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103-112.pdf
Eurographics/ ACM SIGGRAPH Symposium on Computer Animation (2010) M. Otaduy and Z. Popovic (Editors) A Bayesian Interactive Optimization Approach to Procedural Animation Design Eric Brochu Tyson Brochu Nando de Freitas University of British Columbia Abstract The computer graphics and animation fields are filled with applications that require the setting of tricky param-eters. In many cases, the models are complex and the parameters unintuitive for non-experts. In this paper, wepresent an optimization method for setting parameters of a procedural fluid animation system by showing the userexamples of different parametrized animations and asking for feedback. Our method employs the Bayesian tech-nique of bringing in “prior” belief based on previous runs of the system and/or expert knowledge, to assist users infinding good parameter settings in as few steps as possible. To do this, we introduce novel extensions to Bayesianoptimization, which permit effective learning for parameter-based procedural animation applications. We showthat even when users are trying to find a variety of different target animations, the system can learn and improve.We demonstrate the effectiveness of our method compared to related active learning methods. We also present aworking application for assisting animators in the challenging task of designing curl-based velocity fields, evenwith minimal domain knowledge other than identifying when a simulation “looks right”. Categories and Subject Descriptors (according to ACM CCS) : Learning [I.2.6]: Parameter Learning.—User Inter- faces [H.5.2]: Interaction Styles.—Three-Dimensional Graphics and Realism [I.3.7]: Animation.— 1 Introduction Procedural methods for generating animation have long been used by visual effects and games studios due to their effi-ciency and artist controllability. However, this control comeswith a cost: a set of often unintuitive parameters confrontsthe user of a procedural animation system. The desired endresult is often identifiable by the user, but these parametersmust be tuned in a tedious trial-and-error process. For example, realistic animation of smoke can be achieved by driving a particle system through a simple combinationof vortex rings and curl noise [BHN07]. However even thesetwo relatively simple procedural methods are influenced byseveral parameters: The velocity, radius and magnitude ofthe vortex rings, and the length scale and magnitude of thecurl noise. Adding more procedural “flow primitives”, suchas uniform and vortical flows, sources and sinks [WH91],turbulent wind [SF93], vortex particles [SRF05], and vortexfilaments [AN05] can produce a wider variety of animations,but each of these primitives carries its own set of associatedparameters. These parameters can interact in subtle and non-intuitive ways, and small adjustments to certain settings mayresult in non-uniform changes in the appearance. Brochu et al. [BGdF07, BdFG07] propose a Bayesian op- timization technique to assist artists with parameter tuningfor bidirectional reflectance distribution functions (BRDF s). In their iterative scheme, the algorithm selects two sets ofparameters and generates example images from them. Theuser selects the preferred image and the algorithm incorpo-rates this feedback to learn a model of the user’s valuation function over the domain of parameter values. Given thisvaluation function, the algorithm is able to select parame-ters to generate simulations that are likely to be closer to theones wanted by the artist. The process is repeated until theuser is satisfied with the results. During the development of a procedural smoke anima- tion system, we found ourselves with a parameterized sys-tem with 12 continuous parameters. Setting these was a chal-lenge for the developers, let alone other users, so we lookedto adapt [BdFG07]. In the process, though, we found that themodel as presented was unsuitable for our procedural anima-tion. In particular, we identified several limitations: c⃝The Eurographics Association 2010. DOI: 10.2312/SCA/SCA10/103-112
2303.01469.pdf
Consistency Models Yang Song1Prafulla Dhariwal1Mark Chen1Ilya Sutskever1 Abstract Diffusion models have significantly advanced the fields of image, audio, and video generation, but they depend on an iterative sampling process that causes slow generation. To overcome this limita- tion, we propose consistency models , a new fam- ily of models that generate high quality samples by directly mapping noise to data. They support fast one-step generation by design, while still al- lowing multistep sampling to trade compute for sample quality. They also support zero-shot data editing, such as image inpainting, colorization, and super-resolution, without requiring explicit training on these tasks. Consistency models can be trained either by distilling pre-trained diffu- sion models, or as standalone generative models altogether. Through extensive experiments, we demonstrate that they outperform existing distilla- tion techniques for diffusion models in one- and few-step sampling, achieving the new state-of- the-art FID of 3.55 on CIFAR-10 and 6.20 on ImageNet 64ˆ64for one-step generation. When trained in isolation, consistency models become a new family of generative models that can outper- form existing one-step, non-adversarial generative models on standard benchmarks such as CIFAR- 10, ImageNet 64ˆ64and LSUN 256ˆ256. 1. Introduction Diffusion models (Sohl-Dickstein et al., 2015; Song & Er- mon, 2019; 2020; Ho et al., 2020; Song et al., 2021), also known as score-based generative models, have achieved unprecedented success across multiple fields, including im- age generation (Dhariwal & Nichol, 2021; Nichol et al., 2021; Ramesh et al., 2022; Saharia et al., 2022; Rombach et al., 2022), audio synthesis (Kong et al., 2020; Chen et al., 2021; Popov et al., 2021), and video generation (Ho et al., 1OpenAI, San Francisco, CA 94110, USA. Correspondence to: Yang Song <songyang@openai.com >. Proceedings of the 40thInternational Conference on Machine Learning , Honolulu, Hawaii, USA. PMLR 202, 2023. Copyright 2023 by the author(s). Figure 1: Given a Probability Flow (PF) ODE that smoothly converts data to noise, we learn to map any point ( e.g.,xt, xt1, andxT) on the ODE trajectory to its origin ( e.g.,x0) for generative modeling. Models of these mappings are called consistency models, as their outputs are trained to be consistent for points on the same trajectory. 2022b;a). A key feature of diffusion models is the iterative sampling process which progressively removes noise from random initial vectors. This iterative process provides a flexible trade-off of compute and sample quality, as using extra compute for more iterations usually yields samples of better quality. It is also the crux of many zero-shot data editing capabilities of diffusion models, enabling them to solve challenging inverse problems ranging from image inpainting, colorization, stroke-guided image editing, to Computed Tomography and Magnetic Resonance Imaging (Song & Ermon, 2019; Song et al., 2021; 2022; 2023; Kawar et al., 2021; 2022; Chung et al., 2023; Meng et al., 2021). However, compared to single-step generative models like GANs (Goodfellow et al., 2014), V AEs (Kingma & Welling, 2014; Rezende et al., 2014), or normalizing flows (Dinh et al., 2015; 2017; Kingma & Dhariwal, 2018), the iterative generation procedure of diffusion models typically requires 10–2000 times more compute for sample generation (Song & Ermon, 2020; Ho et al., 2020; Song et al., 2021; Zhang & Chen, 2022; Lu et al., 2022), causing slow inference and limited real-time applications. Our objective is to create generative models that facilitate ef- ficient, single-step generation without sacrificing important advantages of iterative sampling, such as trading compute for sample quality when necessary, as well as performing zero-shot data editing tasks. As illustrated in Fig. 1, we build on top of the probability flow (PF) ordinary differen- tial equation (ODE) in continuous-time diffusion models (Song et al., 2021), whose trajectories smoothly transition 1arXiv:2303.01469v2 [cs.LG] 31 May 2023
2402.08797.pdf
Computing Power and the Governance of Artificial Intelligence Girish Sastry,∗†1Lennart Heim,∗†2Haydn Belfield,∗†3 Markus Anderljung,∗2Miles Brundage,∗1Julian Hazell,∗2,4Cullen O’Keefe,∗1,5 Gillian K. Hadfield,∗6,7Richard Ngo,1Konstantin Pilz,8George Gor,9 Emma Bluemke,2Sarah Shoker,1Janet Egan,10Robert F . Trager,11 Shahar Avin,12Adrian Weller,13Yoshua Bengio,14Diane Coyle15 1OpenAI,2Centre for the Governance of AI (GovAI), 3Leverhulme Centre for the Future of Intelligence, Uni. of Cambridge, 4Oxford Internet Institute,5Institute for Law & AI,6University of Toronto 7Vector Institute for AI,8Georgetown University,9ILINA Program,10Harvard Kennedy School, 11AI Governance Institute, Uni. of Oxford,12Centre for the Study of Existential Risk, Uni. of Cambridge, 13Uni. of Cambridge,14Uni. of Montreal /Mila,15Bennett Institute, Uni. of Cambridge February 14, 2024 Abstract Computing power, or "compute," is crucial for the development and deployment of artificial intelligence (AI) capabilities. As a result, governments and companies have started to leverage compute as a means to govern AI. For example, governments are investing in domestic compute capacity, controlling the flow of compute to competing countries, and subsidizing compute access to certain sectors. However, these efforts only scratch the surface of how compute can be used to govern AI development and deployment. Relative to other key inputs to AI (data and algorithms), AI-relevant compute is a particularly effective point of intervention: it is detectable ,excludable , and quantifiable , and is produced via an extremely concentrated supply chain . These characteristics, alongside the singular importance of compute for cutting-edge AI models, suggest that governing compute can contribute to achieving common policy objectives, such as ensuring the safety and beneficial use of AI. More precisely, policymakers could use compute to facilitate regulatory visibility of AI, allocate resources to promote beneficial outcomes, and enforce restrictions against irresponsible or malicious AI development and usage. However, while compute-based policies and technologies have the potential to assist in these areas, there is significant variation in their readiness for implementation. Some ideas are currently being piloted, while others are hindered by the need for fundamental research. Furthermore, naïve or poorly scoped approaches to compute governance carry significant risks in areas like privacy, economic impacts, and centralization of power. We end by suggesting guardrails to minimize these risks from compute governance. Each author contributed ideas and /or writing to the paper. However, being an author does not imply agreement with every claim made in the paper, nor does it represent an endorsement from any author’s respective organization. ∗Denotes primary authors, who contributed most significantly to the direction and content of the paper. Both primary authors and other authors are listed in approximately descending order of contribution. †Indicates the corresponding authors: Girish Sastry (girish@openai.com), Lennart Heim (lennart.heim@governance.ai), and Haydn Belfield (hb492@cam.ac.uk). Figures can be accessed at https://github.com/lheim/CPGAI-Figures . 1arXiv:2402.08797v1 [cs.CY] 13 Feb 2024
2005.04613.pdf
arXiv:2005.04613v1 [cs.CV] 10 May 2020Variational Clustering: Leveraging Variational Autoencoders for Image Clustering Vignesh Prasad* TU Darmstadt Germany vignesh.prasad@tu-darmstadt.deDipanjan Das* Embedded Systems and Robotics TCS Innovation Labs , Kolkata, India dipanjan.da@tcs.comBrojeshwar Bhowmick Embedded Systems and Robotics TCS Innovation Labs , Kolkata, India b.bhowmick@tcs.com Abstract —Recent advances in deep learning have shown their ability to learn strong feature representations for images . The task of image clustering naturally requires good feature re p- resentations to capture the distribution of the data and sub se- quently differentiate data points from one another. Often t hese two aspects are dealt with independently and thus tradition al feature learning alone does not suffice in partitioning the d ata meaningfully. Variational Autoencoders (V AEs) naturally lend themselves to learning data distributions in a latent space . Since we wish to efficiently discriminate between different clust ers in the data, we propose a method based on V AEs where we use a Gaussian Mixture prior to help cluster the images accuratel y. We jointly learn the parameters of both the prior and the poster ior distributions. Our method represents a true Gaussian Mixtu re V AE. This way, our method simultaneously learns a prior that captures the latent distribution of the images and a posteri or to help discriminate well between data points. We also propo se a novel reparametrization of the latent space consisting of a mixture of discrete and continuous variables. One key takea way is that our method generalizes better across different data sets without using any pre-training or learnt models, unlike exi sting methods, allowing it to be trained from scratch in an end-to- end manner. We verify our efficacy and generalizability experim en- tally by achieving state-of-the-art results among unsuper vised methods on a variety of datasets. To the best of our knowledge , we are the first to pursue image clustering using V AEs in a pure ly unsupervised manner on real image datasets. Index Terms —Unsupervised Learning, Clustering, Variational Inference I. I NTRODUCTION Image Clustering is a fundamental, challenging and widely studied problem in machine learning [3]–[8]. with variety o f applications in image retrieval [9], fast 3D reconstructio ns [10] [11] [12] etc. Some classical examples are K-means [13], Gaussian Mixture Models [14] and Spectral clustering [6] which are promising, but require a robust feature represen- tation for good clustering. In recent years, Deep Learning h as made huge progress in learning robust feature representati ons of images. These learned representations help cluster the d ata more accurately when used with traditional methods like K- means for example [15]. One way to use deep representations, off the shelf, is to extract the feature representation of an image from a pre-trained model and use them directly in any This work was done when Vignesh Prasad worked at TCS Innovati on Labs. * - Equal Contributionclustering algorithm [16]. The problem with such approache s is that they don’t fully exploit the power of deep neural networks. Song et al. [17] learn a representation to accurately cluster the images in the dataset by integrating K-means into the bottleneck layer of an Autoencoder. This associati on enables the model to learn a meaningful clustering-oriente d representation. With the motivation to pursue a robust and generalizable methodology in a principled way, we aim to make inferences in a latent space learned specifically for a clustering task. The idea is that it would be easier to group the data in this space, compared to an arbitrary space defined by pre-trained featur es. Off late, the use of generative methods for clustering has be en on the rise as their expressive power helps efficiently captu re, represent and recreate sampled data points. As we wish to experiment with data distributions in a latent space that ca n accurately represent the input data, the paradigm of Variat ional Autoencoders (V AEs) lends itself directly to the task at han d. We build on the ideas of GMV AE [1] and VaDE [2] addressing their fallacies while maintaining the underlyi ng motivation of using a Gaussian Mixture Model as the latent space distribution. Instead of deriving the prior from a ran dom variable, as in GMV AE, our prior is deterministic. This is similar to VaDE however, we learn the parameters for the prio r and posterior jointly, unlike in VaDE which uses a pre-train ing phase to initialize the parameters of the prior. To illustrate the differences between our process, GVMAE [1] and VaDE [2] we visualize the graphical models in Fig. 1. In GMV AE, the Gaussian prior z2depends on a noise variable z1& varies for a given cluster, as shown in Fig. 1a. Ours is more intuitive as it depends only on the cluster, as shown in Fig. 1c. Secondly, GMV AE expresses the categorical posteri or q(k|z1,z2)with the prior pβ(z2|z1,k)using Bayes’ rule. This applies to VaDE too, along with fixing the GMM prior during pre-training. We learn it during training, giving more flexi ble learning, the effectiveness of which is seen in the results i n Table I. This can also be seen on a toy dataset, compared to GMV AE, where our method learns a more compact cluster representation as compared to GMV AE, as shown in Fig. 3. Our method is more principled as we directly learn the cluster assignment probabilities q(k|z)instead of performing a Bayesian classification, as done in both GMV AE and VaDE. Once the cluster predictions q(k|z)become closer to a one-
10.1145.3600006.3613165.pdf
Efficient Memory Management for Large Language Model Serving with PagedAttention Woosuk Kwon1,∗Zhuohan Li1,∗Siyuan Zhuang1Ying Sheng1,2Lianmin Zheng1Cody Hao Yu3 Joseph E. Gonzalez1Hao Zhang4Ion Stoica1 1UC Berkeley2Stanford University3Independent Researcher4UC San Diego Abstract High throughput serving of large language models (LLMs) requires batching sufficiently many requests at a time. How- ever, existing systems struggle because the key-value cache (KV cache) memory for each request is huge and grows and shrinks dynamically. When managed inefficiently, this memory can be significantly wasted by fragmentation and redundant duplication, limiting the batch size. To address this problem, we propose PagedAttention, an attention al- gorithm inspired by the classical virtual memory and pag- ing techniques in operating systems. On top of it, we build vLLM, an LLM serving system that achieves (1) near-zero waste in KV cache memory and (2) flexible sharing of KV cache within and across requests to further reduce mem- ory usage. Our evaluations show that vLLM improves the throughput of popular LLMs by 2-4 ×with the same level of latency compared to the state-of-the-art systems, such as FasterTransformer and Orca. The improvement is more pronounced with longer sequences, larger models, and more complex decoding algorithms. vLLM’s source code is publicly available at https://github.com/vllm-project/vllm . 1 Introduction The emergence of large language models ( LLMs ) like GPT [ 5, 37] and PaLM [ 9] have enabled new applications such as pro- gramming assistants [ 6,18] and universal chatbots [ 19,35] that are starting to profoundly impact our work and daily routines. Many cloud companies [ 34,44] are racing to pro- vide these applications as hosted services. However, running these applications is very expensive, requiring a large num- ber of hardware accelerators such as GPUs. According to recent estimates, processing an LLM request can be 10 ×more expensive than a traditional keyword query [ 43]. Given these high costs, increasing the throughput—and hence reducing Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for third- party components of this work must be honored. For all other uses, contact the owner/author(s). SOSP ’23, October 23–26, 2023, Koblenz, Germany ©2023 Copyright held by the owner/author(s). ACM ISBN 979-8-4007-0229-7/23/10. https://doi.org/10.1145/3600006.3613165 NVIDIA A100 40GBParameters (26GB, 65%)KV Cache(>30%)Others 203040Memory usage (GB) Parameter sizeExisting systems vLLM 0 10 20 30 40 Batch size (# requests)00.4k0.8k1.2kThroughput (token/s) Figure 1. Left: Memory layout when serving an LLM with 13B parameters on NVIDIA A100. The parameters (gray) persist in GPU memory throughout serving. The memory for the KV cache (red) is (de)allocated per serving request. A small amount of memory (yellow) is used ephemerally for activation. Right: vLLM smooths out the rapid growth curve of KV cache memory seen in existing systems [ 31,60], leading to a notable boost in serving throughput. the cost per request—of LLM serving systems is becoming more important. At the core of LLMs lies an autoregressive Transformer model [ 53]. This model generates words (tokens), one at a time, based on the input (prompt) and the previous sequence of the output’s tokens it has generated so far. For each re- quest, this expensive process is repeated until the model out- puts a termination token. This sequential generation process makes the workload memory-bound , underutilizing the com- putation power of GPUs and limiting the serving throughput. Improving the throughput is possible by batching multi- ple requests together. However, to process many requests in a batch, the memory space for each request should be efficiently managed. For example, Fig. 1 (left) illustrates the memory distribution for a 13B-parameter LLM on an NVIDIA A100 GPU with 40GB RAM. Approximately 65% of the mem- ory is allocated for the model weights, which remain static during serving. Close to 30% of the memory is used to store the dynamic states of the requests. For Transformers, these states consist of the key and value tensors associated with the attention mechanism, commonly referred to as KV cache [41], which represent the context from earlier tokens to gener- ate new output tokens in sequence. The remaining small ∗Equal contribution. 1arXiv:2309.06180v1 [cs.LG] 12 Sep 2023
2304.06174.pdf
Accurate transition state generation with an object-aware equivariant elementary reaction diffusion model Chenru Duan1, 2, *, Yuanqi Du3, Haojun Jia1, 2, and Heather J. Kulik1, 2 1Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, 02139 2Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139 3Department of Computer Science, Cornell University, Ithaca, NY , 14850 *Corresponding to: duanchenru@gmail.com Abstract Transition state (TS) search is key in chemistry for elucidating reaction mechanisms and exploring reaction networks. The search for accurate 3D TS structures, however, requires numerous com- putationally intensive quantum chemistry calculations due to the complexity of potential energy surfaces. Here, we developed an object-aware SE(3) equivariant diffusion model that satisfies all physical symmetries and constraints for generating sets of structures – reactant, TS, and product – in an elementary reaction. Provided reactant and product, this model generates a TS structure in seconds instead of hours required when performing quantum chemistry-based optimizations. The generated TS structures achieve a median of 0.08 Å root mean square deviation compared to the true TS. With a confidence scoring model for uncertainty quantification, we approach an accuracy required for reaction rate estimation (2.6 kcal/mol) by only performing quantum chemistry-based optimizations on 14% of the most challenging reactions. We envision the proposed approach useful in constructing large reaction networks with unknown mechanisms. Introduction Breaking down complex chemical reactions into their constituent elementary reactions is key for understanding reaction mechanisms and designing processes that favor target reaction pathways.1–3Due to the transient nature of the intermediate and transition state (TS) involved in these elementary reactions, it is difficult to isolate and characterize these structures experimentally. Instead, high throughput quantum chemistry computation, e.g., with density functional theory (DFT),4provides valuable insights on potential reaction mechanisms by constructing comprehensive reaction networks.2, 5These networks are established by either iteratively enumerating potential elementary reactions on-the-fly given existing species6, 7or propagating biased ab initio molecular dynamics followed by elementary reaction refinement.8–10Both approaches, however, require a tremendous number of quantum chemistry calculations due to the large number of species potentially involved in a chemical reaction.11–13 Among all DFT energy evaluations, the overwhelming majority comes from locating an accurate TS structure solely based on reactant and product information.2, 3Nonetheless, obtaining these TS structures is vital for estimating reaction rates and determining dominant reaction pathways in a reaction network. Conventional TS search algorithms (e.g., nudged elastic band14) are computationally intensive and notorious for their difficulty in convergence,15yielding Preprint. Under review.arXiv:2304.06174v2 [physics.chem-ph] 17 Apr 2023
2207.05221.pdf
Language Models (Mostly) Know What They Know Saurav Kadavath∗, Tom Conerly, Amanda Askell, Tom Henighan, Dawn Drain, Ethan Perez, Nicholas Schiefer, Zac Hatfield-Dodds, Nova DasSarma, Eli Tran-Johnson, Scott Johnston, Sheer El-Showk, Andy Jones, Nelson Elhage, Tristan Hume, Anna Chen, Yuntao Bai, Sam Bowman, Stanislav Fort, Deep Ganguli, Danny Hernandez, Josh Jacobson, Jackson Kernion, Shauna Kravec, Liane Lovitt, Kamal Ndousse, Catherine Olsson, Sam Ringer, Dario Amodei, Tom Brown, Jack Clark, Nicholas Joseph, Ben Mann, Sam McCandlish, Chris Olah, Jared Kaplan∗ Anthropic Abstract We study whether language models can evaluate the validity of their own claims and predict which questions they will be able to answer correctly. We first show that larger models are well-calibrated on diverse multiple choice and true/false questions when they are provided in the right format. Thus we can approach self-evaluation on open-ended sampling tasks by asking models to first propose answers, and then to evaluate the probability "P(True)" that their answers are correct. We find encouraging performance, calibration, and scaling for P(True) on a diverse array of tasks. Performance at self-evaluation further improves when we allow models to consider many of their own samples before predicting the va- lidity of one specific possibility. Next, we investigate whether models can be trained to predict "P(IK)", the probability that "I know" the answer to a question, without reference to any particular proposed answer. Models perform well at predicting P(IK) and partially generalize across tasks, though they struggle with calibration of P(IK) on new tasks. The predicted P(IK) probabilities also increase appropriately in the presence of relevant source materials in the context, and in the presence of hints towards the solution of mathematical word problems. We hope these observations lay the groundwork for training more honest models, and for investigating how honesty generalizes to cases where models are trained on objectives other than the imitation of human writing. ∗Correspondence to: {saurav, jared}@anthropic.com Author contributions are listed at the end of the paper.arXiv:2207.05221v4 [cs.CL] 21 Nov 2022
10.1016.j.cell.2023.04.032.pdf
Article RNA recoding in cephalopods tailors microtubule motor protein function Graphical abstract Highlights dRNA editing in squid specifies unique kinesin protein variants in different tissues dUnique kinesin variants are made acutely in response toseawater temperature dCold-specific kinesin variants have enhanced singlemolecule motility in the cold dCephalopod editomes can reveal functional substitutions innon-cephalopod proteinsAuthors Kavita J. Rangan,Samara L. Reck-Peterson Correspondence krangan@health.ucsd.edu (K.J.R.), sreckpeterson@health.ucsd.edu(S.L.R.-P.) In brief RNA recoding in squid specifies unique kinesin variants with distinct activities indifferent tissues and in response tochanges in seawater temperature, andcephalopod recoding sites provide aguide to identifying functionalsubstitutions in non-cephalopod motorproteins. Rangan & Reck-Peterson, 2023, Cell 186, 2531–2543 June 8, 2023 ª2023 The Author(s). Published by Elsevier Inc. https://doi.org/10.1016/j.cell.2023.04.032 ll
2310.17680.pdf
CODEFUSION : A Pre-trained Diffusion Model for Code Generation Mukul Singh Microsoft Delhi, IndiaJosé Cambronero Sumit Gulwani Vu Le Microsoft Redmond, USCarina Negreanu Microsoft Research Cambridge, UKGust Verbruggen Microsoft Keerbergen, Belgium Abstract Imagine a developer who can only change their last line of code—how often would they have to start writing a function from scratch before it is correct? Auto-regressive models for code generation from natural language have a similar limitation: they do not easily allow reconsid- ering earlier tokens generated. We introduce CODEFUSION , a pre-trained diffusion code gen- eration model that addresses this limitation by iteratively denoising a complete program con- ditioned on the encoded natural language. We evaluate CODEFUSION on the task of natural language to code generation for Bash, Python, and Microsoft Excel conditional formatting (CF) rules. Experiments show that CODEFU - SION (75M parameters) performs on par with state-of-the-art auto-regressive systems (350M– 175B parameters) in top-1 accuracy and outper- forms them in top-3 and top-5 accuracy, due to its better balance in diversity versus quality. 1 Introduction Auto-regressive code generation models (Wang et al., 2021; Brown et al., 2020; Scholak et al., 2021; Feng et al., 2020; Fried et al., 2022) can- not easily reconsider tokens generated earlier in the decoding process. This limitation can lead to lower diversity generations (Lin et al., 2023) in the related domain of text. To balance diversity and quality of candidates generated, prior work has explored decoding strategies such as grouped beam search (Vijayakumar et al., 2018) or nucleus sampling (Holtzman et al., 2019). Diffusion models, which have shown remark- able performance in image generation (Dhariwal and Nichol, 2021), have recently been extended to generate diverse text (Li et al., 2022; Lin et al., 2023). These approaches use an embedding layer to convert discrete tokens to continuous embed- dings, where Gaussian noise can be added and pre- dicted, to imitate the diffusion process. To map denoised embeddings back to discrete text, theseapproaches then select the vocabulary token with the closest embedding. In the code domain, where there are many syntactic and semantic constraints between tokens, independently projecting embed- dings back to tokens can yield invalid programs. We propose CODEFUSION , a natural language to code (NL-to-code) model that combines an encoder-decoder architecture (Raffel et al., 2020) with a diffusion process. The encoder maps the NL into a continuous representation, which is used by the diffusion model as an additional condition for denoising random Gaussian noise input. To generate syntactically correct code, we then feed the denoised embeddings to a transformer decoder, with full self-attention and cross attention with the embedded utterance, to obtain probability distribu- tions over code tokens. Finally, we select the token with the highest probability at each index. To pre-train CODEFUSION for code generation, we extend the continuous paragraph denoising (CPD) task introduced in Lin et al. (2023) to the code domain. Specifically, we only apply noise to tokens that correspond to identifiers in code or to built-in keywords in the target language. This denoising task allows the model to learn relations between critical code tokens (like variable names, function names and control flow built-ins). We find that CODEFUSION yields more diverse code (higher n-gram fraction, lower embedding similarity, and higher edit distance) than auto- regressive models (see Table 2). The CPD objec- tive, which biases the model towards learning to remove noise in a context-aware fashion, paired with a decoder that has access to the full denoised representation, jointly lead CODEFUSION to pro- duce 48.5% more syntactically correct generations (averaged over three languages) when compared to GENIE , a text diffusion model (Table 3). We evaluate CODEFUSION on NL-to-code for three different languages: Python (Yin et al., 2018), Bash (Lin et al., 2018), and conditional formattingarXiv:2310.17680v1 [cs.SE] 26 Oct 2023
2002.05227.pdf
Variational Autoencoders with Riemannian Brownian Motion Priors Dimitris Kalatzis1David Eklund2Georgios Arvanitidis3Søren Hauberg1 Abstract Variational Autoencoders (V AEs) represent the given data in a low-dimensional latent space, which is generally assumed to be Euclidean. This assumption naturally leads to the common choice of a standard Gaussian prior over continuous la- tent variables. Recent work has, however, shown that this prior has a detrimental effect on model capacity, leading to subpar performance. We pro- pose that the Euclidean assumption lies at the heart of this failure mode. To counter this, we as- sume a Riemannian structure over the latent space, which constitutes a more principled geometric view of the latent codes, and replace the stan- dard Gaussian prior with a Riemannian Brownian motion prior. We propose an efficient inference scheme that does not rely on the unknown normal- izing factor of this prior. Finally, we demonstrate that this prior significantly increases model capac- ity using only one additional scalar parameter. 1. Introduction Variational autoencoders (V AEs) (Kingma & Welling, 2014; Rezende et al., 2014) simultaneously learn a conditional densityp(x|z)of high dimensional observations and low dimensional representations zgiving rise to these observa- tions. In V AEs, a prior distribution p(z)is assigned to the latent variables which is typically a standard Gaussian. It has, unfortunately, turned out that this choice of distribution is limiting the modelling capacity of V AEs and richer priors have been proposed instead (Tomczak & Welling, 2017; van den Oord et al., 2017; Bauer & Mnih, 2018; Klushyn et al., 2019). In contrast to this popular view, we will ar- gue that the limitations of the prior are not due to lack of 1Section for Cognitive Systems, Department of Applied Mathe- matics and Computer Science, Technical University of Denmark 2Research Institutes of Sweden, Isafjordsgatan 22, 164 40 Kista, Sweden3Empirical Inference Department, Max Planck Institute for Intelligent Systems, T ¨ubingen, Germany. Correspondence to: Dimitris Kalatzis <dika@dtu.dk >. Proceedings of the 37thInternational Conference on Machine Learning , Vienna, Austria, PMLR 119, 2020. Copyright 2020 by the author(s). Figure 1. The latent space priors of two V AEs trained on the digit 1from MNIST. Left: Using a unit Gaussian prior. Right: Us- ing a Riemannian Brownian motion (ours) with trainable (scalar) variance. capacity , but rather lack of principle . Informally, the Gaussian prior has two key problems. 1. The Euclidean representation is arbitrary. Behind the Gaussian prior lies the assumption that the latent space Zis Euclidean. However, if the decoder pθ(x|z)is of suf- ficiently high capacity, then it is always possible to repa- rameterize the latent space from ztoh(z),h:Z→Z , and then let the decoder invert this reparameterization as part of its decoding process (Arvanitidis et al., 2018; Hauberg, 2018b). This implies that we cannot assign any meaning to specific instantiations of the latent variables, and that Euclidean distances carry limited meaning in Z. This is an identifiability problem and it is well-known that even the most elementary latent variable models are subject to such. For example, Gaussian mixtures can be reparameterized by permuting cluster indices, and principal components can be arbitrarily rotated (Bishop, 2006). 2. Latent manifolds are mismapped onto Z. In all but the simplest cases, the latent manifold Mgiving rise to data observations is embedded in Z. An encoder with adequate capacity will always recover some smoothened form of M, which will either result in the latent space containing “holes” of low density or, in Mbeing mapped to the whole of Z under the influence of the prior. Both cases will lead to bad samples or convergence problems. This problem is called manifold mismatch (Davidson et al., 2018; Falorsi et al., 2018) and is closely related to distribution mismatch (Hoffman & Johnson, 2016; Bauer & Mnih, 2018; Rosca et al., 2018) where the prior samples from regions to which the variational posterior (or encoder) does not assign any density. A graphical illustration of this situation can bearXiv:2002.05227v3 [cs.LG] 7 Aug 2020
10.1038.s41593-023-01304-9.pdf
Nature Neuroscience | Volume 26 | May 2023 | 858–866 858 nature neuroscience Articlehttps://doi.org/10.1038/s41593-023-01304-9 Semantic reconstruction of continuous language from non-invasive brain recordings Jerry Tang1, Amanda LeBel   2, Shailee Jain   1 & Alexander G. Huth   1,2 A brain–computer interface that decodes continuous language from non-invasive recordings would have many scientific and practical applications. Currently, however, non-invasive language decoders can only identify stimuli from among a small set of words or phrases. Here we introduce a non-invasive decoder that reconstructs continuous language from cortical semantic representations recorded using functional magnetic resonance imaging (fMRI). Given novel brain recordings, this decoder generates intelligible word sequences that recover the meaning of perceived speech, imagined speech and even silent videos, demonstrating that a single decoder can be applied to a range of tasks. We tested the decoder across cortex and found that continuous language can be separately decoded from multiple regions. As brain–computer interfaces should respect mental privacy, we tested whether successful decoding requires subject cooperation and found that subject cooperation is required both to train and to apply the decoder. Our findings demonstrate the viability of non-invasive language brain–computer interfaces. Previous brain–computer interfaces have demonstrated that speech articulation1 and other signals2 can be decoded from intracranial recordings to restore communication to people who have lost the ability to speak3,4. Although effective, these decoders require invasive neuro - surgery, making them unsuitable for most other uses. Language decod - ers that use non-invasive recordings could be more widely adopted and have the potential to be used for both restorative and augmentative applications. Non-invasive brain recordings can capture many kinds of linguistic information5–8, but previous attempts to decode this informa - tion have been limited to identifying one output from among a small set of possibilities9–12, leaving it unclear whether current non-invasive recordings have the spatial and temporal resolution required to decode continuous language. Here we introduce a decoder that takes non-invasive brain record - ings made using functional magnetic resonance imaging (fMRI) and reconstructs perceived or imagined stimuli using continuous natural language. To accomplish this, we needed to overcome one major obsta - cle: the low temporal resolution of fMRI. Although fMRI has excellent spatial specificity, the blood-oxygen-level-dependent (BOLD) signal that it measures is notoriously slow—an impulse of neural activity causes BOLD to rise and fall over approximately 10 s (ref. 13). For natu - rally spoken English (over two words per second), this means that each brain image can be affected by over 20 words. Decoding continuous language thus requires solving an ill-posed inverse problem, as there are many more words to decode than brain images. Our decoder accom - plishes this by generating candidate word sequences, scoring the likelihood that each candidate evoked the recorded brain responses and then selecting the best candidate. To compare word sequences to a subject’s brain responses, we used an encoding model5 that predicts how the subject’s brain responds to natural language. We recorded brain responses while the subject listened to 16 h of naturally spoken narrative stories, yielding over five times more data than the typical language fMRI experiment. We trained the encoding model on this dataset by extracting semantic features that capture the meaning of stimulus phrases8,14–17 and using linear regres- sion to model how the semantic features influence brain responses (Fig. 1a). Given any word sequence, the encoding model predicts how the subject’s brain would respond when hearing the sequence with considerable accuracy (Extended Data Fig. 1). The encoding model can then score the likelihood that the word sequence evoked the recorded Received: 1 April 2022 Accepted: 15 March 2023 Published online: 1 May 2023 Check for updates 1Department of Computer Science, The University of Texas at Austin, Austin, TX, USA. 2Department of Neuroscience, The University of Texas at Austin, Austin, TX, USA.  e-mail: huth@cs.utexas.edu
2004.10188.pdf
Journal of Machine Learning Research 21 (2020) 1-41 Submitted 4/20; Revised 10/20; Published 11/20 Residual Energy-Based Models for Text Anton Bakhtin∗∗♦Yuntian Deng∗⋆Sam Gross♦Myle Ott♦ Marc’Aurelio Ranzato♦Arthur Szlam♦ {yolo,sgross,myleott,ranzato,aszlam}@fb.com dengyuntian@seas.harvard.edu ♦Facebook AI Research⋆Harvard University 770 Broadway, New York, NY 10003 33 Oxford St., Cambridge, MA 02138 Editor: Samy Bengio Abstract Current large-scale auto-regressive language models (Radford et al., 2019; Liu et al., 2018; Graves, 2013) display impressive fluency and can generate convincing text. In this work we start by asking the question: Can the generations of these models be reliably distinguished from real text by statistical discriminators? We find experimentally that the answer is affirmative when we have access to the training data for the model, and guardedly affirmative even if we do not. This suggests that the auto-regressive models can be improved by incorporating the (globally normalized) discriminators into the generative process. We give a formalism for this using the Energy-Based Model framework, and show that it indeed improves the results of the generative models, measured both in terms of perplexity and in terms of human evaluation. Keywords: energy-basedmodels, textgeneration, negativesampling, importancesampling, generalization, real/fake discrimination 1. Introduction Energy-based models (EBMs) have a long history in machine learning (Hopfield, 1982; Hinton, 2002a; LeCun et al., 2006), especially in the image domain (Teh et al., 2003; Ranzato et al., 2013). Their appeal stems from the minimal assumptions they make about the generative process of the data: they are a strict generalization of probability models, as the energy function need not be normalized or even have convergent integral. Recent works (Du and Mordatch, 2019) have demonstrated that they can achieve excellent performance as generative models. However, despite several promising efforts (Rosenfeld et al., 2001; Wang et al., 2015, 2017; Wang and Ou, 2017, 2018a), they still have not been as successful in the text domain as locally-normalized auto-regressive models (Radford et al., 2019), which generate each word sequentially conditioned on all previous words (such that the probabilities are normalized per word, hence the name “locally-normalized”). This formulation enables locally-normalized auto-regressive models to be trained efficiently via maximum likelihood and generate samples of remarkable quality. Nevertheless, in the text domain, local normalization and auto-regression leave room for improvement. For example, at training time, standard neural language models (LMs) are ∗Equal contribution. Corresponding author: Marc’Aurelio Ranzato ( ranzato@fb.com ). ©2020 Anton Bakhtin, Yuntian Deng, Sam Gross, Myle Ott, Marc’Aurelio Ranzato, Arthur Szlam. License: CC-BY 4.0, see https://creativecommons.org/licenses/by/4.0/ . Attribution requirements are provided athttp://jmlr.org/papers/v21/20-326.html .arXiv:2004.10188v2 [cs.CL] 21 Dec 2020
2309.03409.pdf
LARGE LANGUAGE MODELS AS OPTIMIZERS Chengrun Yang*Xuezhi Wang Yifeng Lu Hanxiao Liu Quoc V . Le Denny Zhou Xinyun Chen* Google DeepMind*Equal contribution ABSTRACT Optimization is ubiquitous. While derivative-based algorithms have been powerful tools for various problems, the absence of gradient imposes challenges on many real-world applications. In this work, we propose Optimization by PROmpting (OPRO), a simple and effective approach to leverage large language models (LLMs) as optimizers, where the optimization task is described in natural language. In each optimization step, the LLM generates new solutions from the prompt that contains previously generated solutions with their values, then the new solutions are evaluated and added to the prompt for the next optimization step. We first showcase OPRO on linear regression and traveling salesman problems, then move on to prompt optimization where the goal is to find instructions that maximize the task accuracy. With a variety of LLMs, we demonstrate that the best prompts optimized by OPRO outperform human-designed prompts by up to 8%on GSM8K, and by up to 50% on Big-Bench Hard tasks. Code at https://github.com/ google-deepmind/opro . 0 50 100 150 # steps50.060.070.080.0training accuracy GSM8K (a) GSM8K 0 50 100 150 200 # steps60.080.0100.0training accuracy BBH movie_recommendation (b) BBH movie_recommendation Figure 1: Prompt optimization on GSM8K (Cobbe et al., 2021) and BBH (Suzgun et al., 2022) movie_recommendation. The optimization on GSM8K has pre-trained PaLM 2-L as the scorer and the instruction-tuned PaLM 2-L (denoted PaLM 2-L-IT ) as the optimizer; the optimization on BBH movie_recommendation has text-bison as the scorer and PaLM 2-L-IT as the optimizer. Each dot is the average accuracy across all (up to 8) generated instructions in the single step, and the shaded region represents standard deviation. See Section 5 for more details on experimental setup. Table 1: Top instructions with the highest GSM8K zero-shot test accuracies from prompt optimization with different optimizer LLMs. All results use the pre-trained PaLM 2-L as the scorer. Source Instruction Acc Baselines (Kojima et al., 2022) Let’s think step by step. 71.8 (Zhou et al., 2022b) Let’s work this out in a step by step way to be sure we have the right answer. 58.8 (empty string) 34.0 Ours PaLM 2-L-IT Take a deep breath and work on this problem step-by-step. 80.2 PaLM 2-L Break this down. 79.9 gpt-3.5-turbo A little bit of arithmetic and a logical approach will help us quickly arrive at the solution to this problem.78.5 gpt-4 Let’s combine our numerical command and clear thinking to quickly and accurately decipher the answer.74.5 1arXiv:2309.03409v2 [cs.LG] 7 Dec 2023
1810.08575.pdf
Supervising strong learners by amplifying weak experts Paul Christiano OpenAI paul@openai.comBuck Shlegeris∗ bshlegeris@gmail.comDario Amodei OpenAI damodei@openai.com Abstract Many real world learning tasks involve complex or hard-to-specify objectives, and using an easier-to-specify proxy can lead to poor performance or misaligned be- havior. One solution is to have humans provide a training signal by demonstrating or judging performance, but this approach fails if the task is too complicated for a human to directly evaluate. We propose Iterated Amplification, an alternative train- ing strategy which progressively builds up a training signal for difficult problems by combining solutions to easier subproblems. Iterated Amplification is closely related to Expert Iteration (Anthony et al., 2017; Silver et al., 2017b), except that it uses no external reward function. We present results in algorithmic environments, showing that Iterated Amplification can efficiently learn complex behaviors. 1 Introduction If we want to train an ML system to perform a task, we need to be able to evaluate how well it is doing. Whether our training signal takes the form of labels, rewards, or something else entirely, we need some way to generate that signal. If our goal can be evaluated automatically, such as winning a game of Go, or if we have an algorithm that can generate examples of correct behavior, then generating a training signal is trivial. In these cases we might say that there is an “algorithmic” training signal. Unfortunately, most useful tasks don’t have an algorithmic training signal. So in current applications of machine learning, humans often provide the training signal. This can be done by having a human demonstrate the task, for example labeling an image or teleoperating a robot, or by learning a reward function from human judgments. For these classes of tasks, we could say there is a “human” training signal. However, there are harder tasks for which we can’t compute demonstrations or rewards even with human assistance, and for which we currently have no clear method to get a meaningful training signal. Consider making economic policy decisions, advancing the scientific frontier, or managing the security of a large network of computers. Some of these tasks are “beyond human scale” – a single human can’t perform them and can’t make sense of their massive observation space well enough to judge the behavior of an agent. It may be possible for a human to judge performance in the very long run (for example, by looking at economic growth over several years), but such long-term feedback is very slow to learn from. We currently have no way to learn how to perform such tasks much better than a human. The overall situation is depicted in Table 1, which shows six different combinations of training signal source and problem formulation (supervised learning or RL). The bulk of ML practice operates in the top center box (supervised learning from human labels), the bottom left box (RL with a scripted reward), and sometimes the top left box (supervised learning of algorithms). The bottom center box ∗Work done while at OpenAI.arXiv:1810.08575v1 [cs.LG] 19 Oct 2018
2402.06627.pdf
Feedback Loops With Language Models Drive In-Context Reward Hacking Alexander Pan UC Berkeley aypan.17@berkeley.eduErik Jones UC Berkeley erjones@berkeley.eduMeena Jagadeesan UC Berkeley mjagadeesan@berkeley.edu Jacob Steinhardt UC Berkeley jsteinhardt@berkeley.edu Abstract Language models influence the external world: they query APIs that read and write to web pages, generate content that shapes human behavior, and run system commands as autonomous agents. These interactions form feedback loops : LLM outputs affect the world, which in turn affect subsequent LLM outputs. In this work, we show that feedback loops can cause in-context reward hacking (ICRH), where the LLM at test-time optimizes a (potentially implicit) objective but creates negative side effects in the process. For example, consider an LLM agent posting tweets with the objective of maximizing Twitter engagement; the LLM may retrieve its previous tweets into the context window and make its subsequent tweets more controversial, increasing engagement but also toxicity. We identify and study two processes that lead to ICRH: output-refinement andpolicy-refinement . For these processes, evaluations on static datasets are insufficient—they miss the feedback effects and thus cannot capture the most harmful behavior. In response, we provide three recommendations for evaluation to capture more instances of ICRH. As AI development accelerates, the effects of feedback loops will proliferate, increasing the need to understand their role in shaping LLM behavior. 1 Introduction Language models are increasingly influencing the real world. As demand for AI applications accelerates [Benaich et al., 2023], developers are beginning to augment language models (LLMs) with the ability to call external APIs during inference [Mialon et al., 2023], retrieve documents [Jiang et al., 2023], execute code [Zhou et al., 2023a], and act as autonomous agents [Richards, 2023]. LLMs that interact with the world induce feedback loops : the previous outputs affect the world state, which in turn shapes subsequent outputs (Figure 1). For example, Microsoft’s Sydney chat bot (the LLM) interacts with Twitter (the world) by searching through Twitter and placing tweets into its context window. This interaction induced a feedback loop when a user jailbroke Sydney (previous output) and tweeted about it; in a later dialog with the same user, Sydney retrieved the tweet and became hostile (subsequent output) [Perrigo, 2023]. As LLMs are given greater access to tools [OpenAI, 2023b] and deployed in more settings [Grant, 2023], feedback loops will become ubiquitous [Bottou et al., 2013]. In this work, we examine how feedback loops unexpectedly induce optimization in the world-LLM system. Conceptually, when LLMs are deployed with a objective (a goal in natural language), each cycle in the feedback loop provides the LLM with an additional step of computation on the objective. The LLM may use the computation to improve previous outputs (Experiment 1), adjust its policyarXiv:2402.06627v1 [cs.LG] 9 Feb 2024
2308.13731.pdf
Learning variational autoencoders via MCMC speed measures Marcel Hirt1†, Vasileios Kreouzis2†, Petros Dellaportas2,3* 1School of Social Sciences & School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore. 2*Department of Statistical Science, University College London, UK. 3Department of Statistics, Athens University of Economics and Business, Greece. *Corresponding author(s). E-mail(s): p.dellaportas@ucl.ac.uk; †These authors contributed equally to this work. Abstract Variational autoencoders (VAEs) are popular likelihood-based generative models which can be effi- ciently trained by maximizing an Evidence Lower Bound (ELBO). There has been much progress in improving the expressiveness of the variational distribution to obtain tighter variational bounds and increased generative performance. Whilst previous work has leveraged Markov chain Monte Carlo (MCMC) methods for the construction of variational densities, gradient-based methods for adapt- ing the proposal distributions for deep latent variable models have received less attention. This work suggests an entropy-based adaptation for a short-run Metropolis-adjusted Langevin (MALA) or Hamil- tonian Monte Carlo (HMC) chain while optimising a tighter variational bound to the log-evidence. Experiments show that this approach yields higher held-out log-likelihoods as well as improved gener- ative metrics. Our implicit variational density can adapt to complicated posterior geometries of latent hierarchical representations arising in hierarchical VAEs. Keywords: Generative Models,Variational Autoencoders, Adaptive Markov Chain Monte Carlo, Hierarchical Models 1 Introduction VAEs (Kingma and Welling, 2014; Rezende et al, 2014) are powerful latent variable models that routinely use neural networks to parameterise conditional distributions of observations given a latent representation. This renders the Maximum- Likelihood Estimation (MLE) of such models intractable, so one commonly resorts to extensions of Expectation-Maximization (EM) approaches that maximize a lower bound on the data log- likelihood. These objectives introduce a varia- tional or encoding distribution of the latent vari- ables that approximates the true posterior distri- bution of the latent variable given the observation.However, VAEs have shortcomings; for exam- ple, they can struggle to generate high-quality images. These shortcomings have been attributed to failures to match corresponding distributions in the latent space. First, the VAE prior can be significantly different from the aggregated approx- imate posterior (Hoffman and Johnson, 2016; Rosca et al, 2018). To alleviate this prior hole phenomenon, previous work has considered more flexible priors, such as mixtures (Tomczak and Welling, 2017), normalising flows (Kingma et al, 2016), hierarchical priors (Klushyn et al, 2019) or energy-based models (Du and Mordatch, 2019; 1arXiv:2308.13731v1 [stat.ML] 26 Aug 2023
2311.11045.pdf
Orca 2: Teaching Small Language Models How to Reason Arindam Mitra, Luciano Del Corro†, Shweti Mahajan†, Andres Codas‡ Clarisse Simoes‡, Sahaj Agrawal, Xuxi Chen∗, Anastasia Razdaibiedina∗ Erik Jones∗, Kriti Aggarwal∗, Hamid Palangi, Guoqing Zheng Corby Rosset, Hamed Khanpour, Ahmed Awadallah Microsoft Research Abstract Orca 1 learns from rich signals, such as explanation traces, allowing it to outperform conventional instruction-tuned models on benchmarks like BigBench Hard and AGIEval. In Orca 2, we continue exploring how improved training signals can enhance smaller LMs’ reasoning abilities. Research on training small LMs has often relied on imitation learning to replicate the output of more capable models. We contend that excessive emphasis on imitation may restrict the potential of smaller models. We seek to teach small LMs to employ different solution strategies for different tasks, potentially different from the one used by the larger model. For example, while larger models might provide a direct answer to a complex task, smaller models may not have the same capacity. In Orca 2, we teach the model various reasoning techniques (step-by-step, recall then generate, recall-reason-generate, direct answer, etc.). More crucially, we aim to help the model learn to determine the most effective solution strategy for each task. We evaluate Orca 2 using a comprehensive set of 15 diverse benchmarks (corresponding to approximately 100 tasks and over 36,000 unique prompts). Orca 2 significantly surpasses models of similar size and attains performance levels similar or better to those of models 5-10x larger, as assessed on complex tasks that test advanced reasoning abilities in zero-shot settings. We open-source Orca 2 to encourage further research on the development, evaluation, and alignment of smaller LMs. 020406080100 AGI BBH MMLU ARC-E ARC-C RACE GSM8K Average Orca-2-7B Orca-2-13B LLAMA-2-Chat-13B LLAMA-2-Chat-70B WizardLM-13B WizardLM-70B Figure 1: Results comparing Orca 2 (7B & 13B) to LLaMA-2-Chat (13B & 70B) and WizardLM (13B & 70B) on variety of benchmarks (in 0-shot setting) covering language understanding, common sense reasoning, multi-step reasoning, math problem solving, etc. Orca 2 models match or surpass all other models including models 5-10x larger. Note that all models are using the same LLaMA-2 base models of the respective size. ∗work done while at Microsoft;†,‡denote equal contributions.arXiv:2311.11045v1 [cs.AI] 18 Nov 2023
2310.02304.pdf
SELF-TAUGHT OPTIMIZER (STOP ): RECURSIVELY SELF-IMPROVING CODE GENERATION Eric Zelikman1,2, Eliana Lorch, Lester Mackey1, Adam Tauman Kalai1 1Microsoft Research,2Stanford University ABSTRACT Several recent advances in AI systems (e.g., Tree-of-Thoughts and Program-Aided Language Models) solve problems by providing a “scaffolding” program that struc- tures multiple calls to language models to generate better outputs. A scaffolding program is written in a programming language such as Python. In this work, we use a language-model-infused scaffolding program to improve itself. We start with a seed “improver” that improves an input program according to a given utility function by querying a language model several times and returning the best solution. We then run this seed improver to improve itself. Across a small set of downstream tasks, the resulting improved improver generates programs with significantly better performance than its seed improver. A variety of self-improvement strategies are proposed by the language model, including beam search, genetic algorithms, and simulated annealing. Since the language models themselves are not altered, this is not full recursive self-improvement. Nonetheless, it demonstrates that a modern language model, GPT-4 in our proof-of-concept experiments, is capable of writing code that can call itself to improve itself. We consider concerns around the development of self-improving technologies and evaluate the frequency with which the generated code bypasses a sandbox. 1 I NTRODUCTION A language model can be queried to optimize virtually any objective describable in natural language. However, a program that makes multiple, structured calls to a language model can often produce outputs with higher objective values (Yao et al., 2022; 2023; Zelikman et al., 2023; Chen et al., 2022). We refer to these as “scaffolding” programs, typically written (by humans) in a programming language such as Python. Our key observation is that, for any distribution over optimization problems and any fixed language model, the design of a scaffolding program is itself an optimization problem. In this work, we introduce the Self-Taught Optimizer (STOP), a method in which code that applies a language model to improve arbitrary solutions is applied recursively to improve itself. Our approach begins with an initial seed ‘improver’ scaffolding program that uses the language model to improve a solution to some downstream task. As the system iterates, the model refines this improver program. We use a small set of downstream algorithmic tasks to quantify the performance of our self-optimizing framework. Our results demonstrate improvement when the model applies its self-improvement strategies over increasing iterations. Thus, STOP shows how language models can act as their own meta-optimizers. We additionally investigate the kinds of self-improvement strategies that the model proposes (see Figure 1), the transferability of the proposed strategies across downstream tasks, and explore the model’s susceptibility to unsafe self-improvement strategies. Genetic Algorithm Beam Search / Tree Search Multi-Armed Prompt Bandit Vary Temperature to Explore Simulated-annealing Based Search Decomposing and Improving Parts ? Figure 1: Example self-improvement strategies proposed and implemented by GPT-4. Each strategy is then used as scaffolding to revise arbitrary code, including the scaffolding code itself. 1arXiv:2310.02304v1 [cs.CL] 3 Oct 2023
2211.15661.pdf
Published as a conference paper at ICLR 2023 WHAT LEARNING ALGORITHM IS IN -CONTEXT LEARN - ING? INVESTIGATIONS WITH LINEAR MODELS Ekin Aky ¨urek1,2,a.Dale Schuurmans1Jacob Andreas∗2Tengyu Ma∗1,3,bDenny Zhou∗1 1Google Research2MIT CSAIL3Stanford University∗collaborative advising ABSTRACT Neural sequence models, especially transformers, exhibit a remarkable capacity forin-context learning . They can construct new predictors from sequences of labeled examples (x,f(x))presented in the input without further parameter up- dates. We investigate the hypothesis that transformer-based in-context learners implement standard learning algorithms implicitly , by encoding smaller models in their activations, and updating these implicit models as new examples appear in the context. Using linear regression as a prototypical problem, we offer three sources of evidence for this hypothesis. First, we prove by construction that trans- formers can implement learning algorithms for linear models based on gradient descent and closed-form ridge regression. Second, we show that trained in-context learners closely match the predictors computed by gradient descent, ridge regres- sion, and exact least-squares regression, transitioning between different predictors as transformer depth and dataset noise vary, and converging to Bayesian estima- tors for large widths and depths. Third, we present preliminary evidence that in-context learners share algorithmic features with these predictors: learners’ late layers non-linearly encode weight vectors and moment matrices. These results suggest that in-context learning is understandable in algorithmic terms, and that (at least in the linear case) learners may rediscover standard estimation algorithms. 1 I NTRODUCTION One of the most surprising behaviors observed in large neural sequence models is in-context learn- ing(ICL; Brown et al., 2020). When trained appropriately, models can map from sequences of (x,f(x))pairs to accurate predictions f(x′)on novel inputs x′. This behavior occurs both in mod- els trained on collections of few-shot learning problems (Chen et al., 2022; Min et al., 2022) and surprisingly in large language models trained on open-domain text (Brown et al., 2020; Zhang et al., 2022; Chowdhery et al., 2022). ICL requires a model to implicitly construct a map from in-context examples to a predictor without any updates to the model’s parameters themselves. How can a neural network with fixed parameters to learn a new function from a new dataset on the fly? This paper investigates the hypothesis that some instances of ICL can be understood as implicit implementation of known learning algorithms: in-context learners encode an implicit, context- dependent model in their hidden activations, and train this model on in-context examples in the course of computing these internal activations. As in recent investigations of empirical properties of ICL (Garg et al., 2022; Xie et al., 2022), we study the behavior of transformer-based predictors (Vaswani et al., 2017) on a restricted class of learning problems, here linear regression. Unlike in past work, our goal is not to understand what functions ICL can learn, but how it learns these functions: the specific inductive biases and algorithmic properties of transformer-based ICL. In Section 3, we investigate theoretically what learning algorithms transformer decoders can imple- ment. We prove by construction that they require only a modest number of layers and hidden units to train linear models: for d-dimensional regression problems, with O(d)hidden size and constant depth, a transformer can implement a single step of gradient descent; and with O(d2)hidden size aCorrespondence to akyurek@mit.edu. Ekin is a student at MIT, and began this work while he was intern at Google Research. Code and reference implementations are released at this web page bThe work is done when Tengyu Ma works as a visiting researcher at Google Research. 1arXiv:2211.15661v3 [cs.LG] 17 May 2023
2303.04671.pdf
Visual ChatGPT: Talking, Drawing and Editing with Visual Foundation Models Chenfei Wu Shengming Yin Weizhen Qi Xiaodong Wang Zecheng Tang Nan Duan* Microsoft Research Asia {chewu, v-sheyin, t-weizhenqi, v-xiaodwang, v-zetang, nanduan }@microsoft.com Abstract ChatGPT is attracting a cross-field interest as it provides a language interface with remarkable conversational com- petency and reasoning capabilities across many domains. However, since ChatGPT is trained with languages, it is currently not capable of processing or generating images from the visual world. At the same time, Visual Foundation Models, such as Visual Transformers or Stable Diffusion, although showing great visual understanding and genera- tion capabilities, they are only experts on specific tasks with one-round fixed inputs and outputs. To this end, We build a system called Visual ChatGPT , incorporating different Visual Foundation Models, to enable the user to interact with ChatGPT by 1) sending and receiving not only lan- guages but also images 2) providing complex visual ques- tions or visual editing instructions that require the collabo- ration of multiple AI models with multi-steps. 3) providing feedback and asking for corrected results. We design a se- ries of prompts to inject the visual model information into ChatGPT, considering models of multiple inputs/outputs and models that require visual feedback. Experiments show that Visual ChatGPT opens the door to investigating the visual roles of ChatGPT with the help of Visual Founda- tion Models. Our system is publicly available at https: //github.com/microsoft/visual-chatgpt . 1. Introduction In recent years, the development of Large language mod- els (LLMs) has shown incredible progress, such as T5 [32], BLOOM [36], and GPT-3 [5]. One of the most significant breakthroughs is ChatGPT, which is built upon Instruct- GPT [29], specifically trained to interact with users in a gen- uinely conversational manner, thus allowing it to maintain the context of the current conversation, handle follow-up questions, and correct answer produced by itself. Although powerful, ChatGPT is limited in its ability to process visual information since it is trained with a *Corresponding author. BLIPStable Diffusion ControlNet Pix2Pix DetectionVisual Foundation Models User Query please generate a red flower conditioned on the predicted depth of this image and then make it like a cartoon, step by step Iterative Reasoning Outputs Here you are. What else can I help you? ChatGPTPrompt Manager Figure 1. Architecture of Visual ChatGPT. single language modality, while Visual Foundation Mod- els (VFMs) have shown tremendous potential in computer vision, with their ability to understand and generate com- plex images. For instance, BLIP Model [22] is an expert in understanding and providing the description of an image. Stable Diffusion [35] is an expert in synthesizing an image based on text prompts. However, suffering from the task specification nature, the demanding and fixed input-output formats make the VFMs less flexible than conversational language models in human-machine interaction. Could we build a ChatGPT-like system that also supports image understanding and generation? One intuitive idea is to train a multi-modal conversational model. However, building such a system would consume a large amount of data and computational resources. Besides, another chal- lenge comes that what if we want to incorporate modalities beyond languages and images, like videos or voices? Would it be necessary to train a totally new multi-modality model every time when it comes to new modalities or functions? We answer the above questions by proposing a system named Visual ChatGPT . Instead of training a new multi- modal ChatGPT from scratch, we build Visual ChatGPT directly based on ChatGPT and incorporate a variety of VFMs. To bridge the gap between ChatGPT and these VFMs, we propose a Prompt Manager which supports the following functions: 1) explicitly tells ChatGPT the capa- 1arXiv:2303.04671v1 [cs.CV] 8 Mar 2023
2310.03026.pdf
Preprint LANGUAGE MPC: L ARGE LANGUAGE MODELS AS DE- CISION MAKERS FOR AUTONOMOUS DRIVING Hao Sha1, Yao Mu2, Yuxuan Jiang1, Guojian Zhan1, Li Chen2, Chenfeng Xu3, Ping Luo2, Shengbo Eben Li1, Masayoshi Tomizuka3, Wei Zhan3, and Mingyu Ding3,† 1Tsinghua University 2The University of Hong Kong 3University of California, Berkeley ABSTRACT Existing learning-based autonomous driving (AD) systems face challenges in comprehending high-level information, generalizing to rare events, and providing interpretability. To address these problems, this work employs Large Language Models (LLMs) as a decision-making component for complex AD scenarios that require human commonsense understanding. We devise cognitive pathways to en- able comprehensive reasoning with LLMs, and develop algorithms for translating LLM decisions into actionable driving commands. Through this approach, LLM decisions are seamlessly integrated with low-level controllers by guided parameter matrix adaptation. Extensive experiments demonstrate that our proposed method not only consistently surpasses baseline approaches in single-vehicle tasks, but also helps handle complex driving behaviors even multi-vehicle coordination, thanks to the commonsense reasoning capabilities of LLMs. This paper presents an initial step toward leveraging LLMs as effective decision-makers for intricate AD scenarios in terms of safety, efficiency, generalizability, and interoperability. We aspire for it to serve as inspiration for future research in this field. Project page: https://sites.google.com/view/llm-mpc . 1 I NTRODUCTION Imagine you are behind the wheel, approaching an unsignalized intersection and planning to turn left, with an oncoming vehicle straight ahead. Human drivers intuitively know that according to traffic rules, they should slow down and yield, even if it is technically possible to speed through. However, existing advanced learning-based Autonomous Driving (AD) systems typically require complex rules or reward function designs to handle such scenarios effectively (Chen et al., 2023; Kiran et al., 2022). This reliance on predefined rule bases often limits their ability to generalize to various situations. Another challenge facing existing learning-based AD systems is the long-tail problem (Buhet et al., 2019). Both limited datasets and sampling efficiency (Atakishiyev et al., 2023) can present chal- lenges for existing learning-based AD systems when making decisions in rare real-world driving scenarios. Chauffeurnet (Bansal et al., 2018) demonstrated such limits where even 30 million state- action samples were insufficient to learn an optimal policy that mapped bird’s-eye view images (states) to control (action). Furthermore, the lack of interpretability (Gohel et al., 2021) is a pressing issue for existing learning- based AD systems. A mature AD system must possess interpretability to gain recognition within society and regulatory entities, allowing it to be subject to targeted optimization and iterative im- provements. Nevertheless, existing learning-based AD systems inherently resemble black boxes, making it challenging to discern their decision-making processes or understand the rationale behind †Corresponding author. 1arXiv:2310.03026v1 [cs.RO] 4 Oct 2023
2404.14387.pdf
A Survey on Self-Evolution of Large Language Models Zhengwei Tao12*, Ting-En Lin2, Xiancai Chen1, Hangyu Li2, Yuchuan Wu2, Yongbin Li2†,Zhi Jin1†,Fei Huang2,Dacheng Tao3,Jingren Zhou2 1Key Lab of HCST (PKU), MOE; School of Computer Science, Peking University 2Alibaba Group3Nanyang Technological University {tttzw, xiancaich}@stu.pku.edu.cn ,zhijin@pku.edu.cn {ting-en.lte, shengxiu.wyc, shuide.lyb, jingren.zhou}@alibaba-inc.com dacheng.tao@ntu.edu.sg Abstract Large language models (LLMs) have sig- nificantly advanced in various fields and intelligent agent applications. However, current LLMs that learn from human or external model supervision are costly and may face performance ceilings as task complexity and diversity increase. To address this issue, self-evolution approaches that enable LLM to autonomously acquire, refine, and learn from experiences generated by the model itself are rapidly growing. This new training paradigm inspired by the human experiential learning process offers the potential to scale LLMs towards superintelligence. In this work, we present a comprehensive survey of self-evolution approaches in LLMs. We first propose a conceptual framework for self-evolution and outline the evolving process as iterative cycles composed of four phases: experience acquisition, experience refinement, updating, and evaluation. Second, we cate- gorize the evolution objectives of LLMs and LLM-based agents; then, we summarize the literature and provide taxonomy and insights for each module. Lastly, we pinpoint existing challenges and propose future directions to improve self-evolution frameworks, equipping researchers with critical insights to fast-track the development of self-evolving LLMs. Our corresponding GitHub repository is available at https://github.com/AlibabaResearch/DAMO- ConvAI/tree/main/Awesome-Self-Evolution- of-LLM. 1 Introduction With the rapid development of artificial intelli- gence, large language models (LLMs) like GPT- 3.5 (Ouyang et al., 2022), GPT-4 (Achiam et al., 2023), Gemini (Team et al., 2023), LLaMA (Tou- vron et al., 2023a,b), and Qwen (Bai et al., 2023) *Work done while interning at Alibaba Group. †Corresponding authors.mark a significant shift in language understand- ing and generation. These models undergo three stages of development as shown in Figure 1: pre- training on large and diverse corpora to gain a gen- eral understanding of language and world knowl- edge (Devlin et al., 2018; Brown et al., 2020), followed by supervised fine-tuning to elicit the abilities of downstream tasks (Raffel et al., 2020; Chung et al., 2022). Finally, the human prefer- ence alignment training enables the LLMs to re- spond as human behaviors (Ouyang et al., 2022). Such successive training paradigms achieve signif- icant breakthroughs, enabling LLMs to perform a wide range of tasks with remarkable zero-shot and in-context capabilities, such as question an- swering (Tan et al., 2023), mathematical reason- ing (Collins et al., 2023), code generation (Liu et al., 2024b), and task-solving that require interac- tion with environments (Liu et al., 2023b). Despite these advancements, humans anticipate that the emerging generation of LLMs can be tasked with assignments of greater complexity, such as scientific discovery (Miret and Krishnan, 2024) and future events forecasting (Schoenegger et al., 2024). However, current LLMs encounter challenges in these sophisticated tasks due to the inherent difficulties in modeling, annotation, and the evaluation associated with existing training paradigms (Burns et al., 2023). Furthermore, the recently developed Llama-3 model has been trained on an extensive corpus comprising 15 trillion to- kens1. It’s a monumental volume of data, suggest- ing that significantly scaling model performance by adding more real-world data could pose a limi- tation. This has attracted interest in self-evolving mechanisms for LLMs, akin to the natural evolu- tion of human intelligence and illustrated by AI de- velopments in gaming, such as the transition from 1https://huggingface.co/meta-llama/Meta-Llama-3-70B- InstructarXiv:2404.14387v1 [cs.CL] 22 Apr 2024
2302.13971.pdf
LLaMA: Open and Efficient Foundation Language Models Hugo Touvron∗, Thibaut Lavril∗, Gautier Izacard∗, Xavier Martinet Marie-Anne Lachaux, Timothee Lacroix, Baptiste Rozière, Naman Goyal Eric Hambro, Faisal Azhar, Aurelien Rodriguez, Armand Joulin Edouard Grave∗, Guillaume Lample∗ Meta AI Abstract We introduce LLaMA, a collection of founda- tion language models ranging from 7B to 65B parameters. We train our models on trillions of tokens, and show that it is possible to train state-of-the-art models using publicly avail- able datasets exclusively, without resorting to proprietary and inaccessible datasets. In particular, LLaMA-13B outperforms GPT-3 (175B) on most benchmarks, and LLaMA- 65B is competitive with the best models, Chinchilla-70B and PaLM-540B. We release all our models to the research community1. 1 Introduction Large Languages Models (LLMs) trained on mas- sive corpora of texts have shown their ability to per- form new tasks from textual instructions or from a few examples (Brown et al., 2020). These few-shot properties first appeared when scaling models to a sufficient size (Kaplan et al., 2020), resulting in a line of work that focuses on further scaling these models (Chowdhery et al., 2022; Rae et al., 2021). These efforts are based on the assumption that more parameters will lead to better performance. However, recent work from Hoffmann et al. (2022) shows that, for a given compute budget, the best performances are not achieved by the largest mod- els, but by smaller models trained on more data. The objective of the scaling laws from Hoff- mann et al. (2022) is to determine how to best scale the dataset and model sizes for a particular training compute budget. However, this objective disregards the inference budget, which becomes critical when serving a language model at scale. In this context, given a target level of performance, the preferred model is not the fastest to train but the fastest at inference, and although it may be cheaper to train a large model to reach a certain level of ∗Equal contribution. Correspondence: {htouvron, thibautlav,gizacard,egrave,glample}@meta.com 1https://github.com/facebookresearch/llamaperformance, a smaller one trained longer will ultimately be cheaper at inference. For instance, although Hoffmann et al. (2022) recommends training a 10B model on 200B tokens, we find that the performance of a 7B model continues to improve even after 1T tokens. The focus of this work is to train a series of language models that achieve the best possible per- formance at various inference budgets, by training on more tokens than what is typically used. The resulting models, called LLaMA , ranges from 7B to 65B parameters with competitive performance compared to the best existing LLMs. For instance, LLaMA-13B outperforms GPT-3 on most bench- marks, despite being 10 ×smaller. We believe that this model will help democratize the access and study of LLMs, since it can be run on a single GPU. At the higher-end of the scale, our 65B-parameter model is also competitive with the best large lan- guage models such as Chinchilla or PaLM-540B. Unlike Chinchilla, PaLM, or GPT-3, we only use publicly available data, making our work com- patible with open-sourcing, while most existing models rely on data which is either not publicly available or undocumented (e.g. “Books – 2TB” or “Social media conversations”). There exist some exceptions, notably OPT (Zhang et al., 2022), GPT-NeoX (Black et al., 2022), BLOOM (Scao et al., 2022) and GLM (Zeng et al., 2022), but none that are competitive with PaLM-62B or Chinchilla. In the rest of this paper, we present an overview of the modifications we made to the transformer architecture (Vaswani et al., 2017), as well as our training method. We then report the performance of our models and compare with others LLMs on a set of standard benchmarks. Finally, we expose some of the biases and toxicity encoded in our models, using some of the most recent benchmarks from the responsible AI community.arXiv:2302.13971v1 [cs.CL] 27 Feb 2023
2306.04050.pdf
arXiv:2306.04050v2 [cs.IT] 26 Jun 20231 LLMZip: Lossless Text Compression using Large Language Models Chandra Shekhara Kaushik Valmeekam, Krishna Narayanan, Di leep Kalathil, Jean-Francois Chamberland, Srinivas Shakkottai Department of Electrical and Computer Engineering Texas A&M University Email:{vcskaushik9,krn,dileep.kalathil,chmbrlnd,ssh akkot}@tamu.edu Abstract We provide new estimates of an asymptotic upper bound on the e ntropy of English using the large language model LLaMA-7B as a predictor for the next token given a window of past tokens . This estimate is significantly smaller than currently avai lable estimates in [1], [2]. A natural byproduct is an algorithm fo r lossless compression of English text which combines the pr ediction from the large language model with a lossless compression sc heme. Preliminary results from limited experiments sugges t that our scheme outperforms state-of-the-art text compression sch emes such as BSC, ZPAQ, and paq8h. I. I NTRODUCTION There are close connections between learning, prediction, and compression. The success of ChatGPT has captured the fascination of general public and brought the connection be tween learning and prediction to the fore. The main advance brought about by large language models such as LLaMA and GPT- 4 is that they excel at predicting the next word (token) in a paragraph based on knowing the past several words (tokens) . The connection between prediction and compression was expl ored as early as 1951 by Shannon in order to estimate the entropy of the English language [3]. The idea that a good pred ictor for the ith value in a time series based on the past values can be effectively converted to a good compression al gorithm has played a prominent role in information theory. M any algorithms for speech, image, and video compression exploi t this idea either explicitly or implicitly. Within the cont ext of lossless compression of English text, the idea of combining a language model with arithmetic coding has emerged as a very effective paradigm [4]. The performance of such a compressi on scheme depends substantially on the efficacy of the predic tor and every time there is a major advance in the prediction capa bility, it behooves us to study its effect on the compression performance. Indeed, in 2018, the authors of [5] used recurr ent neural networks (RNN) as the predictor and reported impr oved results for certain kinds of sources. Their scheme still did not outperform state-of-the-art algorithms such as BSC and ZPAQ for text compression. It is therefore natural at this time to study whether we can ob tain better compression results and sharper estimates of th e entropy of the English language using recent large language models such as LLaMA-7B [6]. This is the main goal of this paper. We show that when the LLaMA-7B large language model is used as the predictor, the asymptotic upper bound on the entropy is 0.709 bits/character when estimated using a 1MB s ection of the text8 dataset. This is smaller than earlier est imates provided in [1] and [2, Table 4]. The estimate of the upper bou nd increases to 0.85 bits/character for a 100 KB section of the text from [7], which is still lower than the estimates in [ 2]. When LLaMA-7B is combined with an Arithmetic coder for compression, we obtain a compression ratio of 0.7101 bits/c haracter on a 1MB section of the text8 dataset and a compressi on ratio of 0.8426 bits/character on a 100KB section of a text fr om [7], which are significantly better than the compression r atio obtained using BSC, ZPAQ and pq8h on the full 100MB of the text 8 dataset. II. I NTUITIVE EXPLANATION OF THE MAIN IDEA We will use the following example to describe the main idea, w hich is nearly identical to that proposed by Shannon in [3] for estimating the entropy of English. The main difference i s in the use of tokens which represent groups of letters of var iable length and in the use of a large language model instead of a hum an to predict the next token. Consider a part of the sentence that reads as My first attempt at writing a book Our goal is to convert this sentence into a sequence of bits wi th the least possible length such that the original sequence can be reconstructed from the sequence of bits. This sentence ca n first be split into a sequence of words (tokens) ′My′,′first′,′attempt′,′at′,′writing′,′a′,′book′ A language model with memory M(for example, say M= 4) predicts the next word in the sentence based on observing th e pastMwords. Specifically, it produces a rank-ordered list of choi ces for the next word and their probabilities. As shown in
2404.00245.pdf
Aligning Large Language Models with Recommendation Knowledge Yuwei Cao1*, Nikhil Mehta2, Xinyang Yi2, Raghunandan Keshavan3, Lukasz Heldt3, Lichan Hong2, Ed H. Chi2, and Maheswaran Sathiamoorthy4 1University of Illinois Chicago2Google DeepMind3Google 1ycao43@uic.edu2{nikhilmehta ,xinyang }@google.com 4mahesh@smahesh.com Abstract Large language models (LLMs) have recently been used as backbones for recommender sys- tems. However, their performance often lags behind conventional methods in standard tasks like retrieval. We attribute this to a mis- match between LLMs’ knowledge and the knowledge crucial for effective recommenda- tions. While LLMs excel at natural language reasoning, they cannot model complex user- item interactions inherent in recommendation tasks. We propose bridging the knowledge gap and equipping LLMs with recommendation- specific knowledge to address this. Opera- tions such as Masked Item Modeling (MIM) and Bayesian Personalized Ranking (BPR) have found success in conventional recom- mender systems. Inspired by this, we sim- ulate these operations through natural lan- guage to generate auxiliary-task data samples that encode item correlations and user prefer- ences. Fine-tuning LLMs on such auxiliary- task data samples and incorporating more in- formative recommendation-task data samples facilitates the injection of recommendation- specific knowledge into LLMs. Extensive ex- periments across retrieval, ranking, and rating prediction tasks on LLMs such as FLAN-T5- Base and FLAN-T5-XL show the effectiveness of our technique in domains such as Amazon Toys & Games, Beauty, and Sports & Outdoors. Notably, our method outperforms conventional and LLM-based baselines, including the cur- rent SOTA, by significant margins in retrieval, showcasing its potential for enhancing recom- mendation quality. 1 Introduction Large language models (LLMs) exhibit strong gen- eralization abilities through zero-shot learning, in- context learning (Brown et al., 2020), fine-tuning, and instruction tuning (Wei et al., 2022). Encour- aged by this, recent studies explore the use of *Work done when interning at Google.LLMs as backbones in recommendation (Kang et al., 2023; Geng et al., 2022; Zhang et al., 2023; Bao et al., 2023). Despite their great potential, LLMs are inferior to supervised recommenders (He et al., 2017; Rendle et al., 2009) in recom- mendation tasks such as rating-prediction under zero-shot and few-shot in-context learning settings (Kang et al., 2023). We hypothesize that this stems from a gap between LLMs’ knowledge and rec- ommendation knowledge: LLMs are proficient at natural language reasoning, while recommendation involves modeling complex user-item interactions. In this work, we propose to mitigate this gap by fine-tuning LLMs with data samples that encode recommendation knowledge. Recent works (Geng et al., 2022; Zhang et al., 2023; Bao et al., 2023) show that certain recom- mendation knowledge can be introduced into LLMs through instruction tuning. As shown in Figure 1(a), their training data samples, which we refer to as recommendation-task data samples , primar- ily help LLMs understand the recommendation tasks by providing instructions on what to do ( e.g., “Pick an item for the user from the following candi- dates.”). In terms of modeling the target recommen- dation domain, however, they present raw user and item features for personalization ( e.g., the user’s ID or the IDs of the items they recently interacted with), which are insufficient for LLMs to fully com- prehend the target domain. Considering the aforementioned limitations of using LLMs as recommenders, we propose a novel approach to generate additional fine-tuning data samples for LLMs that effectively encode recom- mendation knowledge, particularly focusing on item correlations within the target domain. We refer to these generated data samples as auxiliary- task data samples , as they are used as auxiliary tasks in addition to the recommendations tasks. While developing the auxiliary tasks, our key in- spiration comes from the classical operations thatarXiv:2404.00245v1 [cs.IR] 30 Mar 2024
2312.10794.pdf
A MATHEMATICAL PERSPECTIVE ON TRANSFORMERS BORJAN GESHKOVSKI, CYRIL LETROUIT, YURY POLYANSKIY, AND PHILIPPE RIGOLLET Abstract. Transformers play a central role in the inner workings of large language models. We develop a mathematical framework for analyzing Trans- formers based on their interpretation as interacting particle systems, which reveals that clusters emerge in long time. Our study explores the underlying theory and offers new perspectives for mathematicians as well as computer scientists. Contents 1. Outline 1 Part 1. Modeling 3 2. Interacting particle system 3 3. Measure to measure flow map 9 Part 2. Clustering 14 4. A single cluster in high dimension 14 5. A single cluster for small β 21 Part 3. Further questions 24 6. Dynamics on the circle 24 7. General matrices 26 8. Approximation and control 30 Acknowledgments 31 Appendix 31 Appendix A. Proof of Theorem 4.7 31 Appendix B. Proof of Theorem 5.1 34 Appendix C. Proof of Proposition 6.1 36 References 37 1.Outline The introduction of Transformers in 2017 by Vaswani et al. [VSP`17] marked a significant milestone in development of neural network architectures. Central to 2020Mathematics Subject Classification. Primary: 34D05, 34D06, 35Q83; Secondary: 52C17. Key words and phrases. Transformers, self-attention, interacting particle systems, clustering, gradient flows. 1arXiv:2312.10794v1 [cs.LG] 17 Dec 2023
2312.00752.pdf
Mamba: Linear-Time Sequence Modeling with Selective State Spaces Albert Gu *1and Tri Dao *2 1Machine Learning Department, Carnegie Mellon University 2Department of Computer Science, Princeton University agu@cs.cmu.edu ,tri@tridao.me Abstract Foundation models, now powering most of the exciting applications in deep learning, are almost universally based on the Transformer architecture and its core attention module. Many subquadratic-time architectures such as linear attention, gated convolution and recurrent models, and structured state space models (SSMs) have been developed to address Transformers’ computational inefficiency on long sequences, but they have not performed as well as attention on important modalities such as language. We identify that a key weakness of such models is their inability to perform content-based reasoning, and make several improvements. First, simply letting the SSM parameters be functions of the input addresses their weakness with discrete modalities, allowing the model to selectively propagate or forget information along the sequence length dimension depending on the current token. Second, even though this change prevents the use of efficient convolutions, we design a hardware-aware parallel algorithm in recurrent mode. We integrate these selective SSMs into a simplified end-to-end neural network architecture without attention or even MLP blocks (Mamba). Mamba enjoys fast inference (5 ×higher throughput than Transformers) and linear scaling in sequence length, and its performance improves on real data up to million-length sequences. As a general sequence model backbone, Mamba achieves state-of-the-art performance across several modalities such as language, audio, and genomics. On language modeling, our Mamba-3B model outperforms Transformers of the same size and matches Transformers twice its size, both in pretraining and downstream evaluation. 1 Introduction Foundation models (FMs), or large models pretrained on massive data then adapted for downstream tasks, have emerged as an effective paradigm in modern machine learning. The backbone of these FMs are often sequence models, operating on arbitrary sequences of inputs from a wide variety of domains such as language, images, speech, audio, time series, and genomics (Brown et al. 2020; Dosovitskiy et al. 2020; Ismail Fawaz et al. 2019; Oord et al. 2016; Poli et al. 2023; Sutskever, Vinyals, and Quoc V Le 2014). While this concept is agnostic to a particular choice of model architecture, modern FMs are predominantly based on a single type of sequence model: the Transformer (Vaswani et al. 2017) and its core attention layer (Bahdanau, Cho, and Bengio 2015) The efficacy of self-attention is attributed to its ability to route information densely within a context window, allowing it to model complex data. However, this property brings fundamental drawbacks: an inability to model anything outside of a finite window, and quadratic scaling with respect to the window length. An enormous body of research has appeared on more efficient variants of attention to overcome these drawbacks (Tay, Dehghani, Bahri, et al. 2022), but often at the expense of the very properties that makes it effective. As of yet, none of these variants have been shown to be empirically effective at scale across domains. Recently, structured state space sequence models (SSMs) (Gu, Goel, and Ré 2022; Gu, Johnson, Goel, et al. 2021) have emerged as a promising class of architectures for sequence modeling. These models can be interpreted as a combination of recurrent neural networks (RNNs) and convolutional neural networks (CNNs), with inspiration from classical state space models (Kalman 1960). This class of models can be computed very efficiently as either a recurrence or convolution, with linear or near-linear scaling in sequence length. Additionally, they have principled *Equal contribution. 1
2404.14367v2.pdf
Preference Fine-Tuning of LLMs Should Leverage Suboptimal, On-Policy Data Fahim Tajwar1*, Anikait Singh2*, Archit Sharma2, Rafael Rafailov2, Jeff Schneider1, Tengyang Xie4, Stefano Ermon2, Chelsea Finn2and Aviral Kumar3 *Equal contributions (ordered via coin-flip),1Carnegie Mellon University,2Stanford University,3Google DeepMind,4UW-Madison Learning from preference labels plays a crucial role in fine-tuning large language models. There are several distinct approaches for preference fine-tuning, including supervised learning, on-policy reinforcement learning (RL), and contrastive learning. Different methods come with different implementation tradeoffs and perfor- mance differences, and existing empirical findings present different conclusions, for instance, some results show thatonlineRLisquiteimportanttoattaingoodfine-tuningresults, whileothersfind(offline)contrastiveoreven purely supervised methods sufficient. This raises a natural question: what kind of approaches are important for fine-tuning with preference data and why? In this paper, we answer this question by performing a rigorous analysis of a number of fine-tuning techniques on didactic and full-scale LLM problems. Our main finding is that, in general, approaches that use on-policy sampling or attempt to push down the likelihood on certain responses (i.e., employ a “negative gradient”) outperform offline and maximum likelihood objectives. We conceptualize our insights and unify methods that use on-policy sampling or negative gradient under a notion of mode-seeking objectives for categorical distributions. Mode-seeking objectives are able to alter probability mass on specific bins of a categorical distribution at a fast rate compared to maximum likelihood, allowing them to relocate masses across bins more effectively. Our analysis prescribes actionable insights for preference fine-tuning of LLMs and informs how data should be collected for maximal improvement. 1. Introduction Pre-training endows a large language model (LLM) with knowledge about the world. Yet, it does not provide a lever to control responses from these models, especially when we want these solutions to optimize some task-dependent success criteria (e.g., align with human preferences, optimize correctnessorcompactness). ToalignLLMswithdownstreamsuccesscriteria, theyarethenfine-tuned withdownstreamobjectivesafterpre-training. Inthispaper, wefocusonfine-tuningproblemsthataim tooptimizeforbinarypreferences(fromhumansorotherAImodels). Aplethoraofmethodshavebeen proposed for this sort of fine-tuning, including supervised learning on filtered responses (Gulcehre et al., 2023), contrastive training (Rafailov et al., 2023), and on-policy reinforcement learning (RL) (Ouyang et al., 2022) on a reward function extracted from human preferences. In theory, while all of these methods aim to discover identical optimal policies, achieving this in practice would require full data coverage and infinite computation. These requirements are not met in practice, and hence, the choice of the loss function and the optimization procedure affects performance. However, a lack of a clear understanding of different approaches, coupled with different tradeoffs in implementation, has resulted in substantial confusion: practitioners are unsure as to: (1) whether RL (Ouyang et al., 2022) is required at all, or contrastive approaches (Rafailov et al., 2023; Gheshlaghi Azar et al., 2023), supervised fine-tuning are good enough; and (2)whether preference data should be collected with models in the loop (i.e., in an “on-policy” fashion) or not. Our goal is to provide clarity on these questions by performing a rigorous study to understand the behavior of existing methods when optimizing for preferences. Our study operates under assumptions typical in preference fine-tuning, including the existence of an underlying ground truth reward function that explains the preference data. We study methods that train an LLM policy to optimize a surrogate loss given by the expected reward under a model of the reward function (learned from preference data) penalized by the KL-divergence between the policy and a reference policy. Corresponding author(s): anikait@stanford.edu, ftajwar@cs.cmu.edu. Project Website: https://understanding-rlhf.github.io/arXiv:2404.14367v2 [cs.LG] 23 Apr 2024
10356-a-path-towards-autonomous-mach.pdf
A Path Towards Autonomous Machine Intelligence Version 0.9.2, 2022-06-27 Yann LeCun Courant Institute of Mathematical Sciences, New York University yann@cs.nyu.edu Meta - Fundamental AI Research yann@fb.com June 27, 2022 Abstract How could machines learn as efficiently as humans and animals? How could ma- chines learn to reason and plan? How could machines learn representations of percepts and action plans at multiple levels of abstraction, enabling them to reason, predict, and plan at multiple time horizons? This position paper proposes an architecture and training paradigms with which to construct autonomous intelligent agents. It combines concepts such as configurable predictive world model, behavior driven through intrinsic motivation, and hierarchical joint embedding architectures trained with self-supervised learning. Keywords: Artificial Intelligence, Machine Common Sense, Cognitive Architecture, Deep Learning, Self-Supervised Learning, Energy-Based Model, World Models, Joint Embedding Architecture, Intrinsic Motivation. 1 Prologue This document is not a technical nor scholarly paper in the traditional sense, but a position paper expressing my vision for a path towards intelligent machines that learn more like animals and humans, that can reason and plan, and whose behavior is driven by intrinsic objectives, rather than by hard-wired programs, external supervision, or external rewards. Many ideas described in this paper (almost all of them) have been formulated by many authors in various contexts in various form. The present piece does not claim priority for any of them but presents a proposal for how to assemble them into a consistent whole. In particular, the piece pinpoints the challenges ahead. It also lists a number of avenues that are likely or unlikely to succeed. The text is written with as little jargon as possible, and using as little mathematical prior knowledge as possible, so as to appeal to readers with a wide variety of backgrounds including neuroscience, cognitive science, and philosophy, in addition to machine learning, robotics, and other fields of engineering. I hope that this piece will help contextualize some of the research in AI whose relevance is sometimes difficult to see. 1
2310.14189.pdf
IMPROVED TECHNIQUES FOR TRAINING CONSISTENCY MODELS Yang Song & Prafulla Dhariwal OpenAI {songyang,prafulla}@openai.com ABSTRACT Consistency models are a nascent family of generative models that can sample high quality data in one step without the need for adversarial training. Current consistency models achieve optimal sample quality by distilling from pre-trained diffusion models and employing learned metrics such as LPIPS. However, distil- lation limits the quality of consistency models to that of the pre-trained diffusion model, and LPIPS causes undesirable bias in evaluation. To tackle these challenges, we present improved techniques for consistency training , where consistency mod- els learn directly from data without distillation. We delve into the theory behind consistency training and identify a previously overlooked flaw, which we address by eliminating Exponential Moving Average from the teacher consistency model. To replace learned metrics like LPIPS, we adopt Pseudo-Huber losses from robust statistics. Additionally, we introduce a lognormal noise schedule for the consis- tency training objective, and propose to double total discretization steps every set number of training iterations. Combined with better hyperparameter tuning, these modifications enable consistency models to achieve FID scores of 2.51 and 3.25 on CIFAR-10 and ImageNet 64ˆ64respectively in a single sampling step. These scores mark a 3.5 ˆand 4ˆimprovement compared to prior consistency training approaches. Through two-step sampling, we further reduce FID scores to 2.24 and 2.77 on these two datasets, surpassing those obtained via distillation in both one-step and two-step settings, while narrowing the gap between consistency models and other state-of-the-art generative models. 1 I NTRODUCTION Consistency models (Song et al., 2023) are an emerging family of generative models that produce high-quality samples using a single network evaluation. Unlike GANs (Goodfellow et al., 2014), consistency models are not trained with adversarial optimization and thus sidestep the associated training difficulty. Compared to score-based diffusion models (Sohl-Dickstein et al., 2015; Song & Ermon, 2019; 2020; Ho et al., 2020; Song et al., 2021), consistency models do not require numerous sampling steps to generate high-quality samples. They are trained to generate samples in a single step, but still retain important advantages of diffusion models, such as the flexibility to exchange compute for sample quality through multistep sampling, and the ability to perform zero-shot data editing. We can train consistency models using either consistency distillation (CD) or consistency training (CT). The former requires pre-training a diffusion model and distilling the knowledge therein into a consistency model. The latter allows us to train consistency models directly from data, establishing them as an independent family of generative models. Previous work (Song et al., 2023) demonstrates that CD significantly outperforms CT. However, CD adds computational overhead to the training process since it requires learning a separate diffusion model. Additionally, distillation limits the sample quality of the consistency model to that of the diffusion model. To avoid the downsides of CD and to position consistency models as an independent family of generative models, we aim to improve CT to either match or exceed the performance of CD. For optimal sample quality, both CD and CT rely on learned metrics like the Learned Perceptual Image Patch Similarity (LPIPS) (Zhang et al., 2018) in previous work (Song et al., 2023). However, depending on LPIPS has two primary downsides. Firstly, there could be potential bias in evaluationarXiv:2310.14189v1 [cs.LG] 22 Oct 2023
2309.05858.pdf
Preprint UNCOVERING MESA -OPTIMIZATION ALGORITHMS IN TRANSFORMERS Johannes von Oswald∗,1 ETH Zürich & Google ResearchEyvind Niklasson∗ Google ResearchMaximilian Schlegel∗ ETH ZürichSeijin Kobayashi ETH Zürich Nicolas Zucchet ETH ZürichNino Scherrer Independent ResearcherNolan Miller Google ResearchMark Sandler Google Research Blaise Agüera y Arcas Google ResearchMax Vladymyrov Google ResearchRazvan Pascanu Google DeepMindJoão Sacramento1 ETH Zürich ABSTRACT Transformers have become the dominant model in deep learning, but the reason for their superior performance is poorly understood. Here, we hypothesize that the strong performance of Transformers stems from an architectural bias towards mesa-optimization, a learned process running within the forward pass of a model consisting of the following two steps: ( i) the construction of an internal learn- ing objective, and ( ii) its corresponding solution found through optimization. To test this hypothesis, we reverse-engineer a series of autoregressive Transformers trained on simple sequence modeling tasks, uncovering underlying gradient-based mesa-optimization algorithms driving the generation of predictions. Moreover, we show that the learned forward-pass optimization algorithm can be immediately repurposed to solve supervised few-shot tasks, suggesting that mesa-optimization might underlie the in-context learning capabilities of large language models. Fi- nally, we propose a novel self-attention layer, the mesa-layer, that explicitly and efficiently solves optimization problems specified in context. We find that this layer can lead to improved performance in synthetic and preliminary language modeling experiments, adding weight to our hypothesis that mesa-optimization is an important operation hidden within the weights of trained Transformers. 1 I NTRODUCTION Transformers (Vaswani et al., 2017) and especially large language models (LLMs) are known to strongly adjust their predictions and learn based on data given in-context (Brown et al., 2020). Recently, a number of works have studied this phenomenon in detail by meta-learning Transformers to solve few-shot tasks, providing labeled training sets in context. These studies discovered that Transformers implement learning algorithms that either closely resemble or exactly correspond to gradient-based optimizers (Garg et al., 2022; Akyürek et al., 2023; von Oswald et al., 2023; Kirsch et al., 2022; Zhang et al., 2023; Mahankali et al., 2023; Ahn et al., 2023; Li et al., 2023a). However, it remains unclear how well these findings on meta-trained Transformers translate to models that are autoregressively-trained on sequential data, the prevalent LLM training setup. Here, we address this question by building on the theoretical construction of von Oswald et al. (2023), and show how Transformers trained on sequence modeling tasks predict using gradient-descent learning based on in-context data. Thus, we demonstrate that minimizing a generic autoregressive loss gives rise to a subsidiary gradient-based optimization algorithm running inside the forward pass of a Transformer. This phenomenon has been recently termed mesa-optimization (Hubinger et al., 2019). Moreover, we find that the resulting mesa-optimization algorithms exhibit in-context few-shot learning capabilities, independently of model scale. Our results therefore complement previous reports characterizing the emergence of few-shot learning in large-scale LLMs (Kaplan et al., 2020; Brown et al., 2020). ∗These authors contributed equally to this work.1Correspondence to jvoswald@google.com, rjoao@ethz.ch. 1arXiv:2309.05858v1 [cs.LG] 11 Sep 2023
1711.00937.pdf
Neural Discrete Representation Learning Aaron van den Oord DeepMind avdnoord@google.comOriol Vinyals DeepMind vinyals@google.comKoray Kavukcuoglu DeepMind korayk@google.com Abstract Learning useful representations without supervision remains a key challenge in machine learning. In this paper, we propose a simple yet powerful generative model that learns such discrete representations. Our model, the Vector Quantised- Variational AutoEncoder (VQ-V AE), differs from V AEs in two key ways: the encoder network outputs discrete, rather than continuous, codes; and the prior is learnt rather than static. In order to learn a discrete latent representation, we incorporate ideas from vector quantisation (VQ). Using the VQ method allows the model to circumvent issues of “posterior collapse” -— where the latents are ignored when they are paired with a powerful autoregressive decoder -— typically observed in the V AE framework. Pairing these representations with an autoregressive prior, the model can generate high quality images, videos, and speech as well as doing high quality speaker conversion and unsupervised learning of phonemes, providing further evidence of the utility of the learnt representations. 1 Introduction Recent advances in generative modelling of images [ 38,12,13,22,10], audio [ 37,26] and videos [20,11] have yielded impressive samples and applications [ 24,18]. At the same time, challenging tasks such as few-shot learning [ 34], domain adaptation [ 17], or reinforcement learning [ 35] heavily rely on learnt representations from raw data, but the usefulness of generic representations trained in an unsupervised fashion is still far from being the dominant approach. Maximum likelihood and reconstruction error are two common objectives used to train unsupervised models in the pixel domain, however their usefulness depends on the particular application the features are used in. Our goal is to achieve a model that conserves the important features of the data in its latent space while optimising for maximum likelihood. As the work in [ 7] suggests, the best generative models (as measured by log-likelihood) will be those without latents but a powerful decoder (such as PixelCNN). However, in this paper, we argue for learning discrete and useful latent variables, which we demonstrate on a variety of domains. Learning representations with continuous features have been the focus of many previous work [16,39,6,9] however we concentrate on discrete representations [ 27,33,8,28] which are potentially a more natural fit for many of the modalities we are interested in. Language is inherently discrete, similarly speech is typically represented as a sequence of symbols. Images can often be described concisely by language [ 40]. Furthermore, discrete representations are a natural fit for complex reasoning, planning and predictive learning (e.g., if it rains, I will use an umbrella). While using discrete latent variables in deep learning has proven challenging, powerful autoregressive models have been developed for modelling distributions over discrete variables [37]. In our work, we introduce a new family of generative models succesfully combining the variational autoencoder (V AE) framework with discrete latent representations through a novel parameterisation of the posterior distribution of (discrete) latents given an observation. Our model, which relies on vector quantization (VQ), is simple to train, does not suffer from large variance, and avoids the 31st Conference on Neural Information Processing Systems (NIPS 2017), Long Beach, CA, USA.arXiv:1711.00937v2 [cs.LG] 30 May 2018
1806.07572.pdf
Neural Tangent Kernel: Convergence and Generalization in Neural Networks Arthur Jacot ´Ecole Polytechnique F ´ed´erale de Lausanne arthur.jacot@netopera.net Franck Gabriel Imperial College London and ´Ecole Polytechnique F ´ed´erale de Lausanne franckrgabriel@gmail.com Cl´ement Hongler ´Ecole Polytechnique F ´ed´erale de Lausanne clement.hongler@gmail.com Abstract At initialization, artificial neural networks (ANNs) are equivalent to Gaussian processes in the infinite-width limit ( 16;4;7;13;6), thus connecting them to kernel methods. We prove that the evolution of an ANN during training can also be described by a kernel: during gradient descent on the parameters of an ANN, the network function fθ(which maps input vectors to output vectors) follows the kernel gradient of the functional cost (which is convex, in contrast to the parameter cost) w.r.t. a new kernel: the Neural Tangent Kernel (NTK). This kernel is central to describe the generalization features of ANNs. While the NTK is random at initialization and varies during training, in the infinite-width limit it converges to an explicit limiting kernel and it stays constant during training. This makes it possible to study the training of ANNs in function space instead of parameter space. Convergence of the training can then be related to the positive-definiteness of the limiting NTK. We prove the positive-definiteness of the limiting NTK when the data is supported on the sphere and the non-linearity is non-polynomial. We then focus on the setting of least-squares regression and show that in the infinite- width limit, the network function fθfollows a linear differential equation during training. The convergence is fastest along the largest kernel principal components of the input data with respect to the NTK, hence suggesting a theoretical motivation for early stopping. Finally we study the NTK numerically, observe its behavior for wide networks, and compare it to the infinite-width limit. 1 Introduction Artificial neural networks (ANNs) have achieved impressive results in numerous areas of machine learning. While it has long been known that ANNs can approximate any function with sufficiently many hidden neurons ( 11;14), it is not known what the optimization of ANNs converges to. Indeed the loss surface of neural networks optimization problems is highly non-convex: it has a high number of saddle points which may slow down the convergence ( 5). A number of results ( 3;17;18) suggest that for wide enough networks, there are very few “bad” local minima, i.e. local minima with much 32nd Conference on Neural Information Processing Systems (NIPS 2018), Montr ´eal, Canada.arXiv:1806.07572v4 [cs.LG] 10 Feb 2020
riemann.pdf
A Selbergian Approach to the Riemann Hypothesis via Mochizuki’s Interuniversal Teichm¨ uller Theory HOLOQ March 25, 2024 Abstract We present a novel approach to proving the Riemann Hypothesis by exploit- ing deep connections between the Selberg trace formula, the Euler-Riemann-Siegel theta function, and Mochizuki’s interuniversal Teichm¨ uller theory. Our main re- sult is a conjectural equivalence between the vanishing of a certain integral kernel, constructed using transfinite Atyiah-Hirzebruch-Dwork spectral zetafolds, and the truth of the Riemann Hypothesis. This equivalence arises from the interplay be- tween Weil-Deligne-Langlands autoequivalences of ´ etale motivic Galois groups and the Connes-Kreimer cosmic Galois symmetry. Contents 1 Introduction 1 2 Preliminaries 2 2.1 The Riemann Zeta Function . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.2 Selberg Trace Formula . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2.3 Interuniversal Teichm¨ uller Theory . . . . . . . . . . . . . . . . . . . . . . 3 3 Atyiah-Hirzebruch-Dwork Spectral Zetafolds 3 3.1 Transfinite Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 4 The Integral Kernel 4 5 Main Conjecture 5 6 Future Directions 5 1 Introduction The Riemann Hypothesis, first posited by Bernhard Riemann in 1859, is a conjecture about the location of the non-trivial zeros of the Riemann zeta function ζ(s). It states that all such zeros have real part equal to1 2. Despite its deceptively simple formulation, the Riemann Hypothesis has remained unproven for over 160 years, and is considered one of the most important open problems in mathematics. 1
2010.11929.pdf
Published as a conference paper at ICLR 2021 ANIMAGE IS WORTH 16X16 W ORDS : TRANSFORMERS FOR IMAGE RECOGNITION AT SCALE Alexey Dosovitskiy∗,†, Lucas Beyer∗, Alexander Kolesnikov∗, Dirk Weissenborn∗, Xiaohua Zhai∗, Thomas Unterthiner, Mostafa Dehghani, Matthias Minderer, Georg Heigold, Sylvain Gelly, Jakob Uszkoreit, Neil Houlsby∗,† ∗equal technical contribution,†equal advising Google Research, Brain Team {adosovitskiy, neilhoulsby }@google.com ABSTRACT While the Transformer architecture has become the de-facto standard for natural language processing tasks, its applications to computer vision remain limited. In vision, attention is either applied in conjunction with convolutional networks, or used to replace certain components of convolutional networks while keeping their overall structure in place. We show that this reliance on CNNs is not necessary and a pure transformer applied directly to sequences of image patches can perform very well on image classification tasks. When pre-trained on large amounts of data and transferred to multiple mid-sized or small image recognition benchmarks (ImageNet, CIFAR-100, VTAB, etc.), Vision Transformer (ViT) attains excellent results compared to state-of-the-art convolutional networks while requiring sub- stantially fewer computational resources to train.1 1 I NTRODUCTION Self-attention-based architectures, in particular Transformers (Vaswani et al., 2017), have become the model of choice in natural language processing (NLP). The dominant approach is to pre-train on a large text corpus and then fine-tune on a smaller task-specific dataset (Devlin et al., 2019). Thanks to Transformers’ computational efficiency and scalability, it has become possible to train models of unprecedented size, with over 100B parameters (Brown et al., 2020; Lepikhin et al., 2020). With the models and datasets growing, there is still no sign of saturating performance. In computer vision, however, convolutional architectures remain dominant (LeCun et al., 1989; Krizhevsky et al., 2012; He et al., 2016). Inspired by NLP successes, multiple works try combining CNN-like architectures with self-attention (Wang et al., 2018; Carion et al., 2020), some replacing the convolutions entirely (Ramachandran et al., 2019; Wang et al., 2020a). The latter models, while theoretically efficient, have not yet been scaled effectively on modern hardware accelerators due to the use of specialized attention patterns. Therefore, in large-scale image recognition, classic ResNet- like architectures are still state of the art (Mahajan et al., 2018; Xie et al., 2020; Kolesnikov et al., 2020). Inspired by the Transformer scaling successes in NLP, we experiment with applying a standard Transformer directly to images, with the fewest possible modifications. To do so, we split an image into patches and provide the sequence of linear embeddings of these patches as an input to a Trans- former. Image patches are treated the same way as tokens (words) in an NLP application. We train the model on image classification in supervised fashion. When trained on mid-sized datasets such as ImageNet without strong regularization, these mod- els yield modest accuracies of a few percentage points below ResNets of comparable size. This seemingly discouraging outcome may be expected: Transformers lack some of the inductive biases 1Fine-tuning code and pre-trained models are available at https://github.com/ google-research/vision_transformer 1arXiv:2010.11929v2 [cs.CV] 3 Jun 2021
2404.10719.pdf
Is DPO Superior to PPO for LLM Alignment? A Comprehensive Study Shusheng Xu1Wei Fu1Jiaxuan Gao1Wenjie Ye2Weilin Liu2 Zhiyu Mei1Guangju Wang2Chao Yu* 1Yi Wu* 1 2 3 Abstract Reinforcement Learning from Human Feedback (RLHF) is currently the most widely used method to align large language models (LLMs) with hu- man preferences. Existing RLHF methods can be roughly categorized as either reward-based or reward-free . Novel applications such as ChatGPT and Claude leverage reward-based methods that first learn a reward model and apply actor-critic algorithms, such as Proximal Policy Optimiza- tion (PPO). However, in academic benchmarks, the state-of-the-art results are often achieved via reward-free methods, such as Direct Preference Optimization (DPO). Is DPO truly superior to PPO? Why does PPO perform poorly on these benchmarks? In this paper, we first conduct both theoretical and empirical studies on the algorith- mic properties of DPO and show that DPO may have fundamental limitations. Moreover, we also comprehensively examine PPO and reveal the key factors for the best performances of PPO in fine- tuning LLMs. Finally, we benchmark DPO and PPO across various a collection of RLHF testbeds, ranging from dialogue to code generation. Ex- periment results demonstrate that PPO is able to surpass other alignment methods in all cases and achieve state-of-the-art results in challenging code competitions. 1. Introduction Large Language Models (LLMs) derive their extensive lan- guage patterns and knowledge through pre-training on sub- stantial textual datasets (Brown et al., 2020; OpenAI, 2023; Touvron et al., 2023; Chowdhery et al., 2023; Anil et al., 2023). To leverage the formidable capabilities of LLMs in practical applications, a growing amount of research has *Co-corresponding authors.1Tsinghua University, Beijing China2OpenPsi Inc.3Shanghai Qi Zhi Institute, Shanghai, China. Correspondence to: Shusheng Xu <xssstory@gmail.com >, Chao Yu<zoeyuchao@gmail.com >, Yi Wu <jxwuyi@gmail.com >.underscored the importance of aligning these models with human preferences (Agrawal et al., 2023; Kadavath et al., 2022; Shi et al., 2023; Liang et al., 2021; Sheng et al., 2019). Various methods have been developed for fine-tuning LLMs, with popular approaches including Supervised Fine-Tuning (SFT) (Peng et al., 2023) and Reinforcement Learning from Human Feedback (RLHF) (Ziegler et al., 2019; Stiennon et al., 2020; Ouyang et al., 2022). Typically, fine-tuning in- volves two phases: SFT to establish a base model, followed by RLHF for enhanced performance. SFT involves imitat- ing high-quality demonstration data, while RLHF refines LLMs through preference feedback. Within RLHF, two prominent approaches are reward-based and reward-free methods. Reward-based methods, pio- neered by OpenAI (Ouyang et al., 2022; Ziegler et al., 2019; Stiennon et al., 2020), construct a reward model using pref- erence data and then employ actor-critic algorithms like Proximal Policy Optimization (PPO) to optimize the re- ward signal. In contrast, reward-free methods, including Di- rect Preference Optimization (DPO) (Rafailov et al., 2023), RRHF (Yuan et al., 2023), and PRO (Song et al., 2023), eliminate the explicit use of a reward function. DPO, a representative reward-free method, expresses the reward function in a logarithmic form of the policy and focuses solely on policy optimization. Notably, the most successful applications like Chat- GPT (OpenAI, 2022) and Claude (Antropic, 2023) are pro- duced by the reward-based RLHF method PPO, while strong performances in academic benchmarks often result from the reward-free RLHF method DPO (Rafailov et al., 2023; Mis- tralAI, 2023). This discrepancy raises two fundamental questions: 1) Is DPO truly superior to PPO in the RLHF do- main? and 2) Can the performance of PPO be substantially improved in common RLHF benchmarks? In this paper, we delve into these questions. Through theoretical and empir- ical analysis, we uncover the fundamental limitations of DPO and explore critical factors that enhance the practical performance of PPO in RLHF. First, our theoretical examination reveals that DPO might find biased solutions that exploit out-of-distribution re- sponses. Empirically, we demonstrate that the performance of DPO is significantly affected by the distribution shift 1arXiv:2404.10719v1 [cs.CL] 16 Apr 2024
2305.14699.pdf
Can Transformers Learn to Solve Problems Recursively? Shizhuo Dylan Zhang1Curt Tigges2Stella Biderman2,3Maxim Raginsky1Talia Ringer1 1University of Illinois Urbana-Champaign2EleutherAI3Booz Allen Hamilton {shizhuo2,maxim,tringer}@illinois.edu {curt,stella}@eleuther.ai Abstract Neural networks have in recent years shown promise for helping software engineers write programs and even formally verify them. While semantic information plays a crucial part in these processes, it remains unclear to what degree popular neural architectures like transformers are capable of modeling that information. This paper examines the behavior of neural networks learning algorithms relevant to programs and formal verification proofs through the lens of mechanistic interpretability, focusing in particular on structural recursion. Structural recursion is at the heart of tasks on which symbolic tools currently outperform neural models, like inferring semantic relations between datatypes and emulating program behavior. We evaluate the ability of transformer models to learn to emulate the behavior of structurally recursive functions from input-output examples. Our evaluation includes empirical and conceptual analyses of the limitations and capabilities of transformer models in approximating these functions, as well as reconstructions of the “shortcut” algorithms the model learns. By reconstructing these algorithms, we are able to correctly predict 91% of failure cases for one of the approximated functions. Our work provides a new foundation for understanding the behavior of neural networks that fail to solve the very tasks they are trained for. 1 Introduction A revolution in neural methods for programming languages tasks is underway. Once confined to the realm of symbolic methods, some of the most performant tools for synthesizing [3, 4, 21, 5], repairing [16, 35, 41], and even formally verifying [1, 42, 12, 37, 36, 13] programs now rest in part or in whole upon neural foundations. But how sturdy are these foundations? At the core of many of these tools are transformer-based large language models [4, 5, 13]. It is an open question to what degree these models are simply repeating program syntax, and to what degree they have some model of program semantics —how programs behave and what they mean. State-of-the-art language models still rely on tricks like chain of thought prompting [40] and scratchpadding [28] to approximate program semantics. Even models trained on code often need to be finetuned to solve specific tasks instead of used in a multitask fashion [4, 2, 20]. In this paper, we investigate the degree to which small transformer [38] models can learn to model the semantics of an important class of programs: structural recursion . A program is an example of structural recursion if it is defined over some data structure (say, binary trees) by recursively calling itself over smaller substructures (say, left and right subtrees). Structural recursion is at the heart of important programming and theorem proving tasks for which neural methods still lag behind symbolic methods, like inferring semantic relations between datatypes [34, 33]. Drawing on previous work on reverse engineering neural networks [39, 27, 6], we train small transformer models to solve structural recursion problems and explore the extent to which the models are able to solve Preprint. Under review.arXiv:2305.14699v1 [cs.LG] 24 May 2023
1504.01896.pdf
The Metropolis–Hastings algorithm C.P. Robert1,2,3 1Universit´ e Paris-Dauphine,2University of Warwick, and3CREST Abstract. This article is a self-contained introduction to the Metropolis- Hastings algorithm, this ubiquitous tool for producing dependent simula- tions from an arbitrary distribution. The document illustrates the principles of the methodology on simple examples with R codes and provides entries to the recent extensions of the method. Key words and phrases: Bayesian inference, Markov chains, MCMC meth- ods, Metropolis–Hastings algorithm, intractable density, Gibbs sampler, Langevin diffusion, Hamiltonian Monte Carlo. 1. INTRODUCTION There are many reasons why computing an integral like I(h) =∫ Xh(x)dπ(x), where dπis a probability measure, may prove intractable, from the shape of the domainXto the dimension of X(andx), to the complexity of one of the functionshorπ. Standard numerical methods may be hindered by the same reasons. Similar difficulties (may) occur when attempting to find the extrema ofπover the domain X. This is why the recourse to Monte Carlo methods may prove unavoidable: exploiting the probabilistic nature of πand its weighting of the domainXis often the most natural and most efficient way to produce approximations to integrals connected with πand to determine the regions of the domainXthat are more heavily weighted by π. The Monte Carlo approach (Hammersley and Handscomb, 1964; Rubinstein, 1981) emerged with computers, at the end of WWII, as it relies on the ability of producing a large number of realisations of a random variable distributed according to a given distribution, taking advantage of the stabilisation of the empirical average predicted by the Law of Large Numbers. However, producing simulations from a specific distribution may prove near impossible or quite costly and therefore the (standard) Monte Carlo may also face intractable situations. An indirect approach to the simulation of complex distributions and in par- ticular to the curse of dimensionality met by regular Monte Carlo methods is to use a Markov chain associated with this target distribution, using Markov chain theory to validate the convergence of the chain to the distribution of interest and the stabilisation of empirical averages (Meyn and Tweedie, 1994). It is thus little surprise that Markov chain Monte Carlo (MCMC) methods have been used for almost as long as the original Monte Carlo techniques, even though their impact 1arXiv:1504.01896v3 [stat.CO] 27 Jan 2016
2402.12479.pdf
2024-2-21 In deep reinforcement learning, a pruned network is a good network Johan Obando-Ceron1,2,3, Aaron Courville2,3and Pablo Samuel Castro1,2,3 1Google DeepMind,2Mila - Québec AI Institute,3Université de Montréal Recent work has shown that deep reinforcement learning agents have difficulty in effectively using their network parameters. We leverage prior insights into the advantages of sparse training techniques and demonstrate that gradual magnitude pruning enables agents to maximize parameter effectiveness. This results in networks that yield dramatic performance improvements over traditional networks and exhibit a type of “scaling law”, using only a small fraction of the full network parameters. 1. Introduction Despite successful examples of deep reinforce- ment learning (RL) being applied to real-world problems (Bellemare et al., 2020; Berner et al., 2019; Fawzi et al., 2022; Mnih et al., 2015; Vinyals et al., 2019), there is growing evidence of challenges and pathologies arising when train- ing these networks (Ceron et al., 2023; Graesser etal.,2022;Kumaretal.,2021a;Lyleetal.,2022; Nikishinetal.,2022;Ostrovskietal.,2021;Sokar et al., 2023). In particular, it has been shown that deep RL agents under-utilize their network’s pa- rameters: Kumar et al. (2021a) demonstrated that there is an implicit underparameterization, Sokar et al. (2023) revealed that a large num- ber of neurons go dormant during training, and Graesseretal.(2022)showedthatsparsetraining methods can maintain performance with a very small fraction of the original network parameters. One of the most surprising findings of this last workisthatapplyingthegradualmagnitudeprun- ing technique proposed by Zhu and Gupta (2017) on DQN (Mnih et al., 2015) with a ResNet back- bone (as introduced in Impala (Espeholt et al., 2018)), results in a 50% performance improve- ment over the dense counterpart, with only 10% of the original parameters (see the bottom right panel of Figure 1 of Graesser et al. (2022)). Cu- riously, when the same pruning technique is ap- plied to the original CNN architecture there are no performance improvements, but no degrada- tion either. Thatthesamepruningtechniquecanhavesuch qualitatively different, yet non-negative, results 1 2 3 4 5 Width Scale2.02.53.03.54.04.55.05.5IQM Human Normalized Score Architecture Dense Pruned (95% sparsity)Agent Rainbow DQNFigure1|ScalingnetworkwidthsforResNetar- chitecture ,forDQNandRainbowwithanImpala- based ResNet. We report the interquantile mean after 40 million environment steps, aggregated over 15 games with 5 seeds each; error bars indi- cate95%stratifiedbootstrapconfidenceintervals. by simply changing the underlying architecture is interesting. It suggests that training deep RL agents with non-standard network topologies (as inducedbytechniquessuchasgradualmagnitude pruning) may be generally useful, and warrants a more profound investigation. In this paper we explore gradual magnitude pruning as a general technique for improving the performance of RL agents. We demonstrate that in addition to improving the performance of stan- dard network architectures, the gains increase proportionally with the size of the base network architecture. This last point is significant, as deep RL networks are known to struggle with scaling architectures (Farebrother et al., 2023; Ota et al., 2021; Schwarzer et al., 2023; Taiga et al., 2023). Corresponding author(s): psc@google.com ©2024 Google DeepMind. All rights reservedarXiv:2402.12479v1 [cs.LG] 19 Feb 2024
2203.11171.pdf
Published as a conference paper at ICLR 2023 SELF-CONSISTENCY IMPROVES CHAIN OF THOUGHT REASONING IN LANGUAGE MODELS Xuezhi Wang†‡Jason Wei†Dale Schuurmans†Quoc Le†Ed H. Chi† Sharan Narang†Aakanksha Chowdhery†Denny Zhou†§ †Google Research, Brain Team ‡xuezhiw@google.com ,§dennyzhou@google.com ABSTRACT Chain-of-thought prompting combined with pre-trained large language models has achieved encouraging results on complex reasoning tasks. In this paper, we propose a new decoding strategy, self-consistency , to replace the naive greedy decoding used in chain-of-thought prompting. It first samples a diverse set of reasoning paths instead of only taking the greedy one, and then selects the most consistent answer by marginalizing out the sampled reasoning paths. Self-consistency leverages the intuition that a complex reasoning problem typically admits multiple different ways of thinking leading to its unique correct answer. Our extensive empirical evaluation shows that self-consistency boosts the performance of chain-of-thought prompting with a striking margin on a range of popular arithmetic and commonsense reasoning benchmarks, including GSM8K (+17.9%), SV AMP (+11.0%), AQuA (+12.2%), StrategyQA (+6.4%) and ARC-challenge (+3.9%). 1 I NTRODUCTION Although language models have demonstrated remarkable success across a range of NLP tasks, their ability to demonstrate reasoning is often seen as a limitation, which cannot be overcome solely by increasing model scale (Rae et al., 2021; BIG-bench collaboration, 2021, inter alia ). In an effort to address this shortcoming, Wei et al. (2022) have proposed chain-of-thought prompting , where a language model is prompted to generate a series of short sentences that mimic the reasoning process a person might employ in solving a task. For example, given the question “If there are 3 cars in the parking lot and 2 more cars arrive, how many cars are in the parking lot?” , instead of directly responding with “5”, a language model would be prompted to respond with the entire chain-of-thought: “There are 3 cars in the parking lot already. 2 more arrive. Now there are 3 + 2 = 5 cars. The answer is 5. ” . It has been observed that chain-of-thought prompting significantly improves model performance across a variety of multi-step reasoning tasks (Wei et al., 2022). In this paper, we introduce a novel decoding strategy called self-consistency to replace the greedy decoding strategy used in chain-of-thought prompting (Wei et al., 2022), that further improves language models’ reasoning performance by a significant margin. Self-consistency leverages the intuition that complex reasoning tasks typically admit multiple reasoning paths that reach a correct answer (Stanovich & West, 2000). The more that deliberate thinking and analysis is required for a problem (Evans, 2010), the greater the diversity of reasoning paths that can recover the answer. Figure 1 illustrates the self-consistency method with an example. We first prompt the language model with chain-of-thought prompting, then instead of greedily decoding the optimal reasoning path, we propose a “sample-and-marginalize” decoding procedure: we first sample from the language model’s decoder to generate a diverse set of reasoning paths; each reasoning path might lead to a different final answer, so we determine the optimal answer by marginalizing out the sampled reasoning paths to find the most consistent answer in the final answer set. Such an approach is analogous to the human experience that if multiple different ways of thinking lead to the same answer, one has greater confidence that the final answer is correct. Compared to other decoding methods, self-consistency avoids the repetitiveness and local-optimality that plague greedy decoding, while mitigating the stochasticity of a single sampled generation. 1arXiv:2203.11171v4 [cs.CL] 7 Mar 2023
2308.07037.pdf
Bayesian Flow Networks Alex Graves, Rupesh Kumar Srivastava, Timothy Atkinson, Faustino Gomez {alex,rupesh,timothy,tino }@nnaisense.com NNAISENSE Abstract This paper introduces Bayesian Flow Networks (BFNs), a new class of generative model in which the parameters of a set of independent distributions are modified with Bayesian inference in the light of noisy data samples, then passed as input to a neural network that outputs a second, interdependent distribution. Starting from a simple prior and iteratively updating the two distributions yields a generative procedure similar to the reverse process of diffusion models; however it is conceptually simpler in that no forward process is required. Discrete and continuous-time loss functions are derived for continuous, discretised and discrete data, along with sample generation procedures. Notably, the network inputs for discrete data lie on the probability simplex, and are therefore natively differentiable, paving the way for gradient-based sample guidance and few-step generation in discrete domains such as language modelling. The loss function directly optimises data compression and places no restrictions on the network architecture. In our experiments BFNs achieve competitive log-likelihoods for image modelling on dynamically binarized MNIST and CIFAR-10, and outperform all known discrete diffusion models on the text8 character-level language modelling task. 1 Introduction Large-scale neural networks have revolutionised generative modelling over the last few years, with an unprecedented ability to capture complex relationships among many variables. Building a convincing joint model of all the pixels in a high resolution image, for example, was impossible before the advent of modern generative networks. Key to the expressive power of most of these networks — including autoregressive models [ 9], flow-based models [ 32], deep VAEs [ 48] and diffusion models [ 41] — is that the joint distribution they encode is broken down into a series of steps, thereby eluding the “curse of dimensionality” that would doom any effort to explicitly define all the interactions among so many variables. In colloquial terms they solve a hard problem by splitting it into easy pieces. A general way to view such distributions is as an exchange of messages between a sender, Alice, who has access to some data, and her friend Bob, who wishes to receive it in as few bits as possible. At each step Alice sends a message to Bob that reveals something about the data. Bob attempts to guess what the message is: the better his guess the fewer bits are needed to transmit it. After receiving the message, Bob uses the information he has just gained to improve his guess for the next message. The loss function is the total number of bits required for all the messages. In an autoregressive language model, for example, the messages are the word-pieces the text is divided into. The distribution encoding Bob’s prediction for the first message is of necessity 1arXiv:2308.07037v1 [cs.LG] 14 Aug 2023
2310.07269.pdf
Why Does Sharpness-Aware Minimization Generalize Better Than SGD? Zixiang Chen∗Junkai Zhang∗Yiwen Kou Xiangning Chen Cho-Jui Hsieh Quanquan Gu Department of Computer Science University of California, Los Angeles Los Angeles, CA 90095 {chenzx19,zhang,evankou,xiangning,chohsieh,qgu}@cs.ucla.edu Abstract The challenge of overfitting, in which the model memorizes the training data and fails to generalize to test data, has become increasingly significant in the training of large neural networks. To tackle this challenge, Sharpness-Aware Minimization (SAM) has emerged as a promising training method, which can improve the generalization of neural networks even in the presence of label noise. However, a deep understanding of how SAM works, especially in the setting of nonlinear neural networks and classification tasks, remains largely missing. This paper fills this gap by demonstrating why SAM generalizes better than Stochastic Gradient Descent (SGD) for a certain data model and two-layer convolutional ReLU networks. The loss landscape of our studied problem is nonsmooth, thus current explanations for the success of SAM based on the Hessian information are insufficient. Our result explains the benefits of SAM, particularly its ability to prevent noise learning in the early stages, thereby facilitating more effective learning of features. Experiments on both synthetic and real data corroborate our theory. 1 Introduction The remarkable performance of deep neural networks has sparked considerable interest in creating ever-larger deep learning models, while the training process continues to be a critical bottleneck affecting overall model performance. The training of large models is unstable and difficult due to the sharpness, non-convexity, and non-smoothness of its loss landscape. In addition, as the number of model parameters is much larger than the training sample size, the model has the ability to memorize even randomly labeled data (Zhang et al., 2021), which leads to overfitting. Therefore, although traditional gradient-based methods like gradient descent (GD) and stochastic gradient descent (SGD) can achieve generalizable models under certain conditions, these methods may suffer from unstable training and harmful overfitting in general. To overcome the above challenge, Sharpness-Aware Minimization (SAM) (Foret et al., 2020), an innovative training paradigm, has exhibited significant improvement in model generalization and has become widely adopted in many applications. In contrast to traditional gradient-based methods that primarily focus on finding a point in the parameter space with a minimal gradient norm, SAM also pursues a solution with reduced sharpness, characterized by how rapidly the loss function changes locally. Despite the empirical success of SAM across numerous tasks (Bahri et al., 2021; Behdin et al., 2022; Chen et al., 2021; Liu et al., 2022a), the theoretical understanding of this method remains limited. Foret et al. (2020) provided a PAC-Bayes bound on the generalization error of SAM to show that it will generalize well, while the bound only holds for the infeasible average-direction perturbation instead of ∗Equal contribution. 37th Conference on Neural Information Processing Systems (NeurIPS 2023).arXiv:2310.07269v1 [cs.LG] 11 Oct 2023
2312.11514.pdf
LLM in a flash : Efficient Large Language Model Inference with Limited Memory Keivan Alizadeh, Iman Mirzadeh∗, Dmitry Belenko∗, S. Karen Khatamifard, Minsik Cho, Carlo C Del Mundo, Mohammad Rastegari, Mehrdad Farajtabar Apple† Abstract Large language models (LLMs) are central to modern natural language processing, delivering exceptional performance in various tasks. However, their substantial computational and memory requirements present challenges, especially for devices with limited DRAM capacity. This paper tackles the challenge of efficiently running LLMs that exceed the available DRAM capacity by storing the model parameters in flash memory, but bringing them on demand to DRAM. Our method involves constructing an inference cost model that takes into account the characteristics of flash mem- ory, guiding us to optimize in two critical areas: reducing the volume of data transferred from flash and reading data in larger, more contigu- ous chunks. Within this hardware-informed framework, we introduce two principal techniques. First, “windowing” strategically reduces data transfer by reusing previously activated neurons, and second, “row-column bundling”, tailored to the sequential data access strengths of flash memory, increases the size of data chunks read from flash memory. These methods collectively enable running models up to twice the size of the available DRAM, with a 4-5x and 20-25x increase in inference speed compared to naive loading approaches in CPU and GPU, respectively. Our integration of sparsity awareness, context-adaptive loading, and a hardware-oriented design paves the way for effective inference of LLMs on devices with limited memory. 1 Introduction In recent years, large language models (LLMs), such as GPT-3 (Brown et al., 2020), OPT (Zhang et al., 2022b), and PaLM (Chowdhery et al., 2022), have demonstrated strong performance across a wide range of natural language tasks. However, the ∗Major Contribution †{kalizadehvahid, imirzadeh, d_belenko, skhatamifard, minsik, cdelmundo, mrastegari, farajtabar}@apple.com Naive Falcon 7B (CPU)Ours Naive OPT 6.7B (CPU)Ours Naive OPT6.7B (GPU)Ours10045070022503100Inference Latency (ms)Compute Load From Flash Memory ManagementFigure 1: Inference latency of 1 token when half the memory of the model is available. Our method selec- tively loads parameters on demand per token generation step. The latency is the time needed to load from flash multiple times back and forth during the generation of all tokens and the time needed for the computations, averaged over all generated tokens. unprecedented capabilities of these models come with substantial computational and memory re- quirements for inference. LLMs can contain hun- dreds of billions or even trillions of parameters, which makes them challenging to load and run effi- ciently, especially on resource-constrained devices. Currently, the standard approach is to load the en- tire model into DRAM (Dynamic Random Access Memory) for inference (Rajbhandari et al., 2021; Aminabadi et al., 2022). However, this severely limits the maximum model size that can be run. For example, a 7 billion parameter model requires over 14GB of memory just to load the parameters in half-precision floating point format, exceeding the capabilities of most edge devices. To address this limitation, we propose to store the model parameters in flash memory, which is at least an order of magnitude larger than DRAM. Then, during inference, we directly load the re- quired subset of parameters from the flash mem- 1arXiv:2312.11514v2 [cs.CL] 4 Jan 2024
10.1101.2022.05.17.492325.pdf
Inferring Neural Activity Before Plasticity: A Foundation 1 for Learning Beyond Backpropagation 2 Yuhang Song1,2,*, Beren Millidge2, Tommaso Salvatori1, Thomas Lukasiewicz1,*, Zhenghua Xu1,3, and 3 Rafal Bogacz2,*4 1Department of Computer Science, University of Oxford, Oxford, United Kingdom 5 2Medical Research Council Brain Networks Dynamics Unit, University of Oxford, Oxford, United Kingdom 6 3State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, China 7 *Corresponding authors: yuhang.song@bndu.ox.ac.uk; thomas.lukasiewicz@cs.ox.ac.uk; rafal.bogacz@ndcn.ox.ac.uk 8 Abstract9 For both humans and machines, the essence of learning is to pinpoint which components in its information processing pipeline are responsible for an error in its output — a challenge that is known as credit assignment. How the brain solves credit assignment is a key question in neuroscience, and also of significant importance for artificial intelligence. It has long been assumed that credit assignment is best solved by backpropagation, which is also the foundation of modern machine learning. However, it has been questioned whether it is possible for the brain to implement backpropagation and learning in the brain may actually be more efficient and effective than backpropagation. Here, we set out a fundamentally different principle on credit assignment, called prospective configuration. In prospective configuration, the network first infers the pattern of neural activity that should result from learning, and then the synaptic weights are modified to consolidate the change in neural activity. We demonstrate that this distinct mechanism, in contrast to backpropagation, (1) underlies learning in a well-established family of models of cortical circuits, (2) enables learning that is more efficient and effective in many contexts faced by biological organisms, and (3) reproduces surprising patterns of neural activity and behaviour observed in diverse human and animal learning experiments. Our findings establish a new foundation for learning beyond backpropagation, for both understanding biological learning and building artificial intelligence.10 The credit assignment problem1lies at the very heart of learning. Backpropagation2–5, as a simple 11 yet effective credit assignment theory, has powered notable advances in artificial intelligence since its 12 inception6–11. It has also gained a predominant place in understanding learning in the brain1,12–21. Due to 13 this success, much recent work has focused on understanding how biological neural networks could learn in 14 a way similar to backpropagation22–31: although many proposed models do not implement backpropagation 15 exactly, they nevertheless try to approximate backpropagation, and much emphasis is placed on how 16 close this approximation is22–28, 32–34. However, learning in the brain is superior to backpropagation 17 in many critical aspects — for example, compared to the brain, backpropagation requires many more 18 exposures to a stimulus to learn35and suffers from catastrophic interference of newly and previously 19 stored information36,37. This raises the question of whether using backpropagation to understand learning 20 in the brain should be the main focus of the field. 21 Here, we propose that the brain instead solves credit assignment with a fundamentally different 22 principle, which we call prospective configuration. In prospective configuration, before synaptic weights 23 are modified, neural activity changes across the network so that output neurons better predict the target 24 output; only then are the synaptic weights (weights, for short) modified to consolidate this change in 25 neural activity. By contrast, in backpropagation the order is reversed — weight modification takes the lead 26 1(which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. The copyright holder for this preprint this version posted October 12, 2022. ; https://doi.org/10.1101/2022.05.17.492325doi: bioRxiv preprint
2402.01613.pdf
Nomic Embed: Training a Reproducible Long Context Text Embedder Zach Nussbaum zach@nomic.aiJohn X. Morris jack@nomic.ai jxm3@cornell.edu Brandon Duderstadt brandon@nomic.aiAndriy Mulyar andriy@nomic.ai Abstract This technical report describes the training of nomic-embed-text-v1, the first fully re- producible, open-source, open-weights, open- data, 8192 context length English text em- bedding model that outperforms both OpenAI Ada-002 and OpenAI text-embedding-3-small on short and long-context tasks. We release the training code and model weights under an Apache 2 license. In contrast with other open-source models, we release a training data loader with 235 million curated text pairs that allows for the full replication of nomic-embed- text-v1. You can find code and data to repli- cate the model at https://github.com/nomic- ai/contrastors. 1 Introduction Text embeddings are an integral component of modern NLP applications powering retrieval- augmented-generation (RAG) for LLMs and se- mantic search (Lewis et al., 2021a; Izacard et al., 2022b; Ram et al., 2023). These embeddings en- code semantic information about sentences or doc- uments as low-dimensional vectors that are used in downstream applications, such as clustering for data visualization, classification, and information retrieval. The majority of the top open-source models on the MTEB benchmark (Muennighoff et al., 2023) are limited to context lengths of 512, such as E5 Wang et al. (2022), GTE Li et al. (2023), and BGE Xiao et al. (2023). This short context length reduces model utility in domains where overall document semantics are not localized to sentences or paragraphs. Most top embedding models with a context length longer than 2048 are closed-source, such as V oyage-lite-01-instruct V oyage (2023) and text-embedding-ada-002 Nee- lakantan et al. (2022). The top two performing open-source long con- text embedding models are jina-embedding-v2-50 55 60 65 70 75 80 85JinaLCLoCoMTEB 60.99 52.7 55.2562.26 82.4 58.260.39 85.45 51.962.39 85.53 54.16Nomic Embed Jina Base V2 text-embedding-3-small text-embedding-ada Figure 1: Text Embedding Model Benchmarks. Ag- gregate performance of nomic-embed-text-v1, OpenAI text-embedding-ada, OpenAI text-embedding-3-small and jina-embedding-base-v2 on short and long con- text benchmarks. Nomic Embed is the only fully au- ditable long-context model that exceeds OpenAI text- embedding-ada, OpenAI text-embedding-3-small, and Jina performance across both short and long context benchmarks. X-axis units vary per benchmark suite. base-en G ¨unther et al. (2024) and E5-Mistral-7b- instruct Wang et al. (2023b). Unfortunately, jina-embedding-v2-base does not surpass OpenAI’s text-embedding-ada-002 Neelakantan et al. (2022) (see Table 1). Further, E5-Mistral Wang et al. (2023b) is not feasible to use in many engineering applications due to the large inference requirements of a 7B parameter transformer, and is not recommended for use be- yond 4096 tokens. This report describes how we trained nomic- embed-text-v1, a 137M parameter, open-source, open-weights, open-data, 8192 sequence length model that surpasses OpenAI text-embedding-ada and text-embedding-3-small performance on both short and long context benchmarks (Table 1). We release the model weights and codebase under an Apache-2 license. We additionally release our curated training dataset to enable end-to-end au- ditability and replication of the model.arXiv:2402.01613v1 [cs.CL] 2 Feb 2024
2309.16039.pdf
Effective Long-Context Scaling of Foundation Models Wenhan Xiong†∗, Jingyu Liu†, Igor Molybog, Hejia Zhang, Prajjwal Bhargava, Rui Hou, Louis Martin, Rashi Rungta, Karthik Abinav Sankararaman, Barlas Oguz, Madian Khabsa, Han Fang, Yashar Mehdad, Sharan Narang, Kshitiz Malik, Angela Fan, Shruti Bhosale, Sergey Edunov, Mike Lewis, Sinong Wang∗, Hao Ma∗ Meta Abstract We present a series of long-context LLMs that support effective context windows of up to 32,768 tokens. Our model series are built through continual pretraining from LLAMA 2with longer training sequences and on a dataset where long texts are upsampled. We perform extensive evaluation on language modeling, synthetic context probing tasks, and a wide range of research benchmarks. On research benchmarks, our models achieve consistent improvements on most regular tasks and significant improvements on long-context tasks over LLAMA 2. Notably, with a cost-effective instruction tuning procedure that does not require human-annotated long instruction data, the 70B variant can already surpass gpt-3.5-turbo-16k ’s overall performance on a suite of long-context tasks. Alongside these results, we provide an in-depth analysis on the individual components of our method. We delve into LLAMA ’s position encodings and discuss its limitation in modeling long dependencies. We also examine the impact of various design choices in the pretraining process, including the data mix and the training curriculum of sequence lengths – our ablation experiments suggest that having abundant long texts in the pretrain dataset is notthe key to achieving strong performance, and we empirically verify that long context continual pretraining is more efficient and similarly effective compared to pretraining from scratch with long sequences. 100101102103104 Context length23456Validation loss Llama 2 Long 7B = 25.4, = 0.45, = 1.56 Llama 2 Long 13B = 19.5, = 0.48, = 1.45 Llama 2 Long 34B = 17.7, = 0.50, = 1.41 Llama 2 Long 70B = 17.9, = 0.51, = 1.35 Figure 1: We show that our model’s validation loss can be fit as a function of the context length: L(c) = (α c)β+γwith a different set of α, β, γ for each model size. This power-law relationship also suggests that context length is another important axis of scaling LLMs and our model can continually improve its performance as we increase the context length up to 32,768 tokens.arXiv:2309.16039v1 [cs.CL] 27 Sep 2023
blei03a.pdf
Journalof Machine Learning Research 3 (2003)993-1022 Submitted 2/02; Published 1/03 Latent Dirichlet Allocation David M. Blei BLEI@CS.BERKELEY .EDU Computer Science Division University of CaliforniaBerkeley, CA 94720, USA Andrew Y. Ng ANG@CS.STANFORD .EDU Computer Science DepartmentStanford UniversityStanford, CA 94305, USA Michael I.Jordan JORDAN@CS.BERKELEY .EDU Computer Science Division and Department of Statistics University of CaliforniaBerkeley, CA 94720, USA Editor:John Lafferty Abstract We describe latent Dirichlet allocation (LDA), a generative probabilistic model for collections of discretedatasuchastextcorpora. LDAisathree-levelhierarchicalBayesianmodel,inwhicheachitemofacollectionismodeledasafinitemixtureoveranunderlyingsetoftopics. Eachtopicis,inturn, modeled as an infinite mixture over an underlying set of topic probabilities. In the context oftext modeling, the topic probabilities provide an explicit representation of a document. We presentefficient approximate inference techniques based on variational methods and an EM algorithm forempiricalBayesparameterestimation. Wereportresultsindocumentmodeling,textclassification,and collaborative filtering, comparing to a mixture of unigrams model and the probabilistic LSImodel. 1. Introduction In this paper we consider the problem of modeling text corpora and other collections of discrete data. The goal is to find short descriptions of the members of a collection that enable efficientprocessing of large collections while preserving the essential statistical relationships that are usefulforbasictaskssuchasclassification,noveltydetection,summarization,andsimilarityandrelevancejudgments. Significant progress has been made on this problem by researchers in the field of informa- tion retrieval (IR) (Baeza-Yates and Ribeiro-Neto, 1999). The basic methodology proposed byIR researchers for text corpora—a methodology successfully deployed in modern Internet searchengines—reduces each document in the corpus to a vector of real numbers, each of which repre-sents ratios of counts. In the popular tf-idfscheme (Salton and McGill, 1983), a basic vocabulary of “words” or “terms” is chosen, and, for each document in the corpus, a count is formed of thenumber of occurrences of each word. After suitable normalization, this term frequency count iscomparedtoaninversedocumentfrequencycount,whichmeasuresthenumberofoccurrencesofa c⃝2003David M. Blei, Andrew Y. Ng and Michael I.Jordan.
2204.06860.pdf
AlphaFold2 can predict single-mutation effects John M. McBride,1,∗Konstantin Polev,1, 2Amirbek Abdirasulov,3 Vladimir Reinharz,4Bartosz A. Grzybowski,1, 5, †and Tsvi Tlusty1, 5, ‡ 1Center for Soft and Living Matter, Institute for Basic Science, Ulsan 44919, South Korea 2Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea 3Department of Computer Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea 4Université du Québec à Montréal, Canada 5Departments of Physics and Chemistry, Ulsan National Institute of Science and Technology, Ulsan 44919, South Korea AlphaFold2 (AF) is a promising tool, but is it accurate enough to predict single mutation effects? Here, we report that the localized structural deformation between protein pairs differing by only 1-3 mutations – as mea- sured by the effective strain – is correlated across 3,901 experimental and AF-predicted structures. Furthermore, analysis of ∼11,000 proteins shows that the local structural change correlates with various phenotypic changes. These findings suggest that AF can predict the range and magnitude of single-mutation effects on average, and we propose a method to improve precision of AF predictions and to indicate when predictions are unreliable. Alteration of one or few amino acid residues can af- fect structure [1–3] and function [4, 5] of a protein and, in extreme cases, be the difference between health and dis- ease [6, 7]. Understanding structural consequences of point mutations is important for drug design [8, 9] and could also accelerate optimization of enzymatic function via directed evolution [10, 11]. In these and other applications, theoret- ical models [12] could be of immense help, provided they are sufficiently accurate. In this context, AlphaFold2 [13] has recently made breakthroughs in predicting global pro- tein structure from sequence with unprecedented precision. Notwithstanding, it is not yet known whether AF is sen- sitive enough to detect small, local effects of single muta- tions. Even if AF achieves high accuracy, the effect of a mutation may be small compared to the inherent confor- mational dynamics of the protein – predicting static struc- tures may not be particularly informative [14–16]. Further- more, as accuracy improves, evaluating the quality of pre- dictions becomes increasingly complicated by the inherent noise in experimental measurements [16–23]. So far, no study has evaluated whether AF can accurately measure structural changes due to single mutations, and there are conflicting reports as to whether AF can predict the effect of a mutation on protein stability [24–28]. Furthermore, re- cent evidence suggests that AF learns the energy functional underlying folding, raising the question of whether the in- ferred functional is sensitive enough to discern the subtle physical changes due to a single mutation [29]. We aim to resolve this issue by comparing AF predictions with exten- sive data on protein structure and function. We examine AF predictions in light of structural data from a curated set of proteins from the Protein Data Bank (PDB) [30], and phenotype data from high-throughput ex- periments [31–33]. We find that AF can detect the ef- fect of a mutation on structure by identifying local de- formations between protein pairs differing by 1-3 muta- tions. The deformation is probed by the effective strain (ES) measure. We show that ES computed between a pair of PDB structures is correlated with the ES computed for the corresponding pair of structures predicted by AF. Furthermore, analysis of ∼11,000 proteins whose function was probed in three high-throughput studies shows sig- nificant correlations between AF-predicted ES and three categories of phenotype (fluorescence, folding, catalysis)across three experimental data sets [31–33]. These sets of correlations suggest that AF can predict the range and mag- nitude of single-mutation effects. We provide new tools (github.com/mirabdi/PDAnalysis) for computing deforma- tion in proteins, and a methodology for increasing the pre- cision of AlphaFold predictions of mutation effects. Alto- gether, these results indicate that AF can be used to pre- dict physicochemical effects of missense mutations, un- damming vast potential in the field of protein design and evolution. AF can predict local structural change.— We illustrate our approach by analyzing wild-type (WT; 6BDD_A ) and single- mutant ( 6BDE_A , A71G) structures of H-NOX protein from K. algicida (Fig. 1D) [34]. To quantify local deformation, we calculate the effective strain (ES) per residue Si(See App. A) for, respectively, experimental and AF-predicted pairs of structures (Fig. 1A). The ES is the mean relative change in distance from C αof residue ito neighboring Cαpositions within a range of 13 Å. ES provides a ro- bust estimate of the magnitude of local strain, which ac- counts also for non-affine deformation in addition to affine deformation [35–39]. Like the frame-aligned-point-error (FAPE) measure used in training AF [13], ES is invariant to alignment. In H-NOX, we observe that the Siis highest at, and decays away from the mutated site, showing a cor- relation with the distance from the mutated site (Fig. 1B). We find that Siis correlated across PDB and AF structures (Fig. 1C,E). Taken together, these correlations suggest that Siis a sensitive measure of local structural change, and that AF is capable of predicting such structural change upon mutation. Experimental measurement variability limits evaluation.— Before exploring AF predictions in more detail, we first ex- amine variation within experimental structures by compar- ing repeat measurements of the same protein. In Fig. 1F we show the distribution of Sicalculated for all residues in all pairs (Supplemental Material (SM) Sec. 1A [40]) of pro- tein structures with identical sequences (number of muta- tions, M=0); we excluded pairs where the crystallographic group differed (SM Sec. 1B [40]). Protein structures vary considerably between repeat measurements (average ES is ⟨Si⟩=0.018, and the average Root Mean Square Deviation is RMSD =0.24Å). In comparison, differences between repeat predictions of AF are much lower ( ∆Si=0.005,arXiv:2204.06860v7 [q-bio.BM] 21 Oct 2023
2404.14619.pdf
OpenELM: An Efficient Language Model Family with Open-source Training and Inference Framework Sachin Mehta Mohammad Hossein Sekhavat Qingqing Cao Maxwell Horton Yanzi Jin Chenfan Sun Iman Mirzadeh Mahyar Najibi Dmitry Belenko Peter Zatloukal Mohammad Rastegari Apple Model Public datasetOpen-sourceModel size Pre-training tokens Average acc. (in %) Code Weights OPT [55] ✗ ✓ ✓ 1.3 B 0.2 T 41.49 PyThia [5] ✓ ✓ ✓ 1.4 B 0.3 T 41.83 MobiLlama [44] ✓ ✓ ✓ 1.3 B 1.3 T 43.55 OLMo [17] ✓ ✓ ✓ 1.2 B 3.0 T 43.57 OpenELM (Ours) ✓ ✓ ✓ 1.1 B 1.5 T 45.93 Table 1. OpenELM vs. public LLMs. OpenELM outperforms comparable-sized existing LLMs pretrained on publicly available datasets. Notably, OpenELM outperforms the recent open LLM, OLMo, by 2.36% while requiring 2×fewer pre-training tokens. The average accuracy is calculated across multiple tasks listed in Tab. 3b, which are also part of the OpenLLM leaderboard [4]. Models pretrained with less data are highlighted in gray color. Abstract The reproducibility and transparency of large language models are crucial for advancing open research, ensuring the trustworthiness of results, and enabling investigations into data and model biases, as well as potential risks. To this end, we release OpenELM, a state-of-the-art open lan- guage model. OpenELM uses a layer-wise scaling strategy to efficiently allocate parameters within each layer of the transformer model, leading to enhanced accuracy. For ex- ample, with a parameter budget of approximately one bil- lion parameters, OpenELM exhibits a 2.36% improvement in accuracy compared to OLMo while requiring 2×fewer pre-training tokens. Diverging from prior practices that only provide model weights and inference code, and pre-train on private datasets, our release includes the complete framework for training and evaluation of the language model on publicly available datasets, including training logs, multiple check- points, and pre-training configurations. We also release code to convert models to MLX library for inference and fine-tuning on Apple devices. This comprehensive release aims to empower and strengthen the open research commu- nity, paving the way for future open research endeavors. Our source code along with pre-trained model weights and training recipes is available at https://github. com/apple/corenet . Additionally, OpenELM mod-els can be found on HuggingFace at: https : / / huggingface.co/apple/OpenELM . 1. Introduction Transformer-based [48] large language models (LLM) are revolutionizing the field of natural language processing [7, 46]. These models are isotropic, meaning that they have the same configuration ( e.g., number of heads and feed- forward network dimensions) for each transformer layer. Though such isotropic models are simple, they may not al- locate parameters efficiently inside the model. In this work, we develop and release OpenELM, a fam- ily of pre-trained and fine-tuned models on publicly avail- able datasets. At the core of OpenELM lies layer-wise scaling [30], enabling more efficient parameter allocation across layers. This method utilizes smaller latent dimen- sions in the attention and feed-forward modules of the trans- former layers closer to the input, and gradually widening the layers as they approach the output. We release the complete framework, encompassing data preparation, training, fine-tuning, and evaluation proce- dures, alongside multiple pre-trained checkpoints and train- ing logs, to facilitate open research. Importantly, OpenELM outperforms existing open LLMs that are pre-trained us- ing publicly available datasets (Tab. 1). For example, OpenELM with 1.1 billion parameters outperforms OLMo 1arXiv:2404.14619v1 [cs.CL] 22 Apr 2024
1312.6114.pdf
Auto-Encoding Variational Bayes Diederik P. Kingma Machine Learning Group Universiteit van Amsterdam dpkingma@gmail.comMax Welling Machine Learning Group Universiteit van Amsterdam welling.max@gmail.com Abstract How can we perform efficient inference and learning in directed probabilistic models, in the presence of continuous latent variables with intractable posterior distributions, and large datasets? We introduce a stochastic variational inference and learning algorithm that scales to large datasets and, under some mild differ- entiability conditions, even works in the intractable case. Our contributions are two-fold. First, we show that a reparameterization of the variational lower bound yields a lower bound estimator that can be straightforwardly optimized using stan- dard stochastic gradient methods. Second, we show that for i.i.d. datasets with continuous latent variables per datapoint, posterior inference can be made espe- cially efficient by fitting an approximate inference model (also called a recogni- tion model) to the intractable posterior using the proposed lower bound estimator. Theoretical advantages are reflected in experimental results. 1 Introduction How can we perform efficient approximate inference and learning with directed probabilistic models whose continuous latent variables and/or parameters have intractable posterior distributions? The variational Bayesian (VB) approach involves the optimization of an approximation to the intractable posterior. Unfortunately, the common mean-field approach requires analytical solutions of expecta- tions w.r.t. the approximate posterior, which are also intractable in the general case. We show how a reparameterization of the variational lower bound yields a simple differentiable unbiased estimator of the lower bound; this SGVB (Stochastic Gradient Variational Bayes) estimator can be used for ef- ficient approximate posterior inference in almost any model with continuous latent variables and/or parameters, and is straightforward to optimize using standard stochastic gradient ascent techniques. For the case of an i.i.d. dataset and continuous latent variables per datapoint, we propose the Auto- Encoding VB (AEVB) algorithm. In the AEVB algorithm we make inference and learning especially efficient by using the SGVB estimator to optimize a recognition model that allows us to perform very efficient approximate posterior inference using simple ancestral sampling, which in turn allows us to efficiently learn the model parameters, without the need of expensive iterative inference schemes (such as MCMC) per datapoint. The learned approximate posterior inference model can also be used for a host of tasks such as recognition, denoising, representation and visualization purposes. When a neural network is used for the recognition model, we arrive at the variational auto-encoder . 2 Method The strategy in this section can be used to derive a lower bound estimator (a stochastic objective function) for a variety of directed graphical models with continuous latent variables. We will restrict ourselves here to the common case where we have an i.i.d. dataset with latent variables per datapoint, and where we like to perform maximum likelihood (ML) or maximum a posteriori (MAP) inference on the (global) parameters, and variational inference on the latent variables. It is, for example, 1arXiv:1312.6114v11 [stat.ML] 10 Dec 2022
2103.04047.pdf
Reinforcement Learning, Bit by Bit Suggested Citation: Xiuyuan Lu, Benjamin Van Roy, Vikranth Dwaracherla, Morteza Ibrahimi, Ian Osband and Zheng Wen (2018), “Reinforcement Learning, Bit by Bit”, : Vol. xx, No. xx, pp 1–18. DOI: 10.1561/XXXXXXXXX. Xiuyuan Lu DeepMind lxlu@deepmind.comBenjamin Van Roy DeepMind benvanroy@deepmind.com Vikranth Dwaracherla DeepMind vikranthd@deepmind.comMorteza Ibrahimi DeepMind mibrahimi@deepmind.com Ian Osband DeepMind iosband@deepmind.comZheng Wen DeepMind zhengwen@deepmind.com This article may be used only for the purpose of research, teaching, and/or private study. Commercial use or systematic downloading (by robots or other automatic processes) is prohibited without ex- plicit Publisher approval.Boston — DelftarXiv:2103.04047v8 [cs.LG] 4 May 2023
10.1101.2020.12.15.422761.pdf
TRANSFORMER PROTEIN LANGUAGE MODELS ARE UNSUPERVISED STRUCTURE LEARNERS Roshan Rao∗ UC Berkeley rmrao@berkeley.eduJoshua Meier Facebook AI Research jmeier@fb.comTom Sercu Facebook AI Research tsercu@fb.com Sergey Ovchinnikov Harvard University so@g.harvard.eduAlexander Rives Facebook AI Research & New York University arives@cs.nyu.edu ABSTRACT Unsupervised contact prediction is central to uncovering physical, structural, and functional constraints for protein structure determination and design. For decades, the predominant approach has been to infer evolutionary constraints from a set of related sequences. In the past year, protein language models have emerged as a po- tential alternative, but performance has fallen short of state-of-the-art approaches in bioinformatics. In this paper we demonstrate that Transformer attention maps learn contacts from the unsupervised language modeling objective. We find the highest capacity models that have been trained to date already outperform a state- of-the-art unsupervised contact prediction pipeline, suggesting these pipelines can be replaced with a single forward pass of an end-to-end model.1 1 I NTRODUCTION Unsupervised modeling of protein contacts has an important role in computational protein de- sign (Russ et al., 2020; Tian et al., 2018; Blazejewski et al., 2019) and is a central element of all current state-of-the-art structure prediction methods (Wang et al., 2017; Senior et al., 2020; Yang et al., 2019). The standard bioinformatics pipeline for unsupervised contact prediction includes mul- tiple components with specialized tools and databases that have been developed and optimized over decades. In this work we propose replacing the current multi-stage pipeline with a single forward pass of a pre-trained end-to-end protein language model. In the last year, protein language modeling with an unsupervised training objective has been inves- tigated by multiple groups (Rives et al., 2019; Alley et al., 2019; Heinzinger et al., 2019; Rao et al., 2019; Madani et al., 2020). The longstanding practice in bioinformatics has been to fit linear models on focused sets of evolutionarily related and aligned sequences; by contrast, protein language model- ing trains nonlinear deep neural networks on large databases of evolutionarily diverse and unaligned sequences. High capacity protein language models have been shown to learn underlying intrinsic properties of proteins such as structure and function from sequence data (Rives et al., 2019). A line of work in this emerging field proposes the Transformer for protein language modeling (Rives et al., 2019; Rao et al., 2019). Originally developed in the NLP community to represent long range context, the main innovation of the Transformer model is its use of self-attention (Vaswani et al., 2017). Self-attention has particular relevance for the modeling of protein sequences. Unlike convo- lutional and recurrent LSTM models, the Transformer constructs a pairwise interaction map between all positions in the sequence. In principle this mechanism has an ideal form to model residue-residue contacts. In theory, end-to-end learning with a language model has advantages over the bioinformatics pipeline: (i) it replaces the expensive query, alignment, and training steps with a single forward ∗Work performed during an internship at Facebook. 1Weights for all ESM-1 and ESM-1b models, as well as regressions trained on these models can be found athttps://github.com/facebookresearch/esm. 1. CC-BY-NC-ND 4.0 International license perpetuity. It is made available under apreprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in The copyright holder for this this version posted December 15, 2020. ; https://doi.org/10.1101/2020.12.15.422761doi: bioRxiv preprint
2401.16405.pdf
Scaling Sparse Fine-Tuning to Large Language Models Alan Ansell1Ivan Vuli ´c1Hannah Sterz1Anna Korhonen1Edoardo M. Ponti2 1 Abstract Large Language Models (LLMs) are difficult to fully fine-tune (e.g., with instructions or human feedback) due to their sheer number of parameters. A family of parameter -efficient sparse fine-tuning methods have proven promising in terms of per- formance but their memory requirements increase proportionally to the size of the LLMs. In this work, we scale sparse fine-tuning to state-of-the- art LLMs like LLaMA 2 7B and 13B. We propose SpIEL, a novel sparse fine-tuning method which, for a desired density level, maintains an array of parameter indices and the deltas of these parame- ters relative to their pretrained values. It iterates over: (a) updating the active deltas, (b) pruning indices (based on the change of magnitude of their deltas) and (c) regrowth of indices. For regrowth, we explore two criteria based on either the accu- mulated gradients of a few candidate parameters or their approximate momenta estimated using the efficient SM3 optimizer. We experiment with instruction-tuning of LLMs on standard dataset mixtures, finding that SpIEL is often superior to popular parameter-efficient fine-tuning methods like LoRA (low-rank adaptation) in terms of per- formance and comparable in terms of run time. We additionally show that SpIEL is compatible with both quantization and efficient optimizers, to facilitate scaling to ever-larger model sizes. We re- lease the code for SpIEL at https://github. com/AlanAnsell/peft and for the instruc- tion-tuning experiments at https://github. com/ducdauge/sft-llm . 1. Introduction The scale of Large Language Models (LLMs), such as Fal- con (Almazrouei et al., 2023), LLaMA 2 (Touvron et al., 2023), and Mistral (Jiang et al., 2023), is one of the keys 1University of Cambridge2University of Edinburgh. Corre- spondence to: Alan Ansell <aja63@cam.ac.uk >.to their state-of-the-art performance (Kaplan et al., 2020). However, this scale is both a blessing and a curse as tailor- ing LLMs to specific applications via fine-tuning presents a formidable challenge: if performed na ¨ıvely, this incurs the cost of updating an incredibly large set of parameters. A family of lightweight methods for LLM adaptation have been proposed to mitigate this issue, known collectively as Parameter-Efficient Fine-Tuning (PEFT). PEFT meth- ods learn a small number of new parameters, denoted as ϕ, which augment the frozen LLM weights θ(Pfeiffer et al., 2023; Lialin et al., 2023). For instance, Low-Rank Adapters (LoRA; Hu et al., 2022) learn additional low-rank matrices to modify the linear layers in Transformer blocks. PEFT methods based on unstructured sparse fine-tuning (SFT1), where ϕis a sparse vector added to θ, have recently shown promise (Sung et al., 2021; Guo et al., 2021; Ansell et al., 2022). These offer a strong trade-off between low number of parameters and high model performance without inserting additional layers into the LLM’s neural architec- ture, which would reduce model efficiency. In addition, multiple SFTs are composable while avoiding interference (Ansell et al., 2022), which facilitates the integration of multiple sources of knowledge into LLMs. Formally, SFT can be conceived of as performing joint optimization over the fixed-size set of non-zero indices of ϕand their deltas with respect to the LLM weights. Due to the intricacies of this optimization, however, SFT has so far been severely limited by a major drawback, namely, its high memory re- quirements: existing methods for selecting non-zero indices include learning a mask (Sung et al., 2021), estimating the Fisher information (Guo et al., 2021), or calculating the difference between initialization and convergence (Ansell et al., 2022) for all LLM parameters . Hence, SFT is not currently suitable for adapting LLM at large scales. The main goal of this work is to overcome these challenges by devising memory-efficient methods to update Large Lan- guage Models (LLMs) sparsely, while maintaining perfor- mance benefits, that is, retaining the same performance of full-model fine-tuning or even surpassing it. Specifically, we wish for the memory use during training (beyond that required to store the pretrained model weights) to scale 1Note the unfortunate confusion of nomenclature with super- vised fine-tuning (also frequently referred to as SFT). 1arXiv:2401.16405v2 [cs.CL] 2 Feb 2024
2308.03296.pdf
Studying Large Language Model Generalization with Influence Functions Roger Grosse˚:, Juhan Bae˚:, Cem Anil˚: Nelson Elhage; Alex Tamkin, Amirhossein Tajdini, Benoit Steiner, Dustin Li, Esin Durmus, Ethan Perez, Evan Hubinger, Kamil˙ e Lukoši¯ ut˙ e, Karina Nguyen, Nicholas Joseph, Sam McCandlish Jared Kaplan, Samuel R. Bowman Abstract When trying to gain better visibility into a machine learning model in order to understand and mitigate the associated risks, a potentially valuable source of evidence is: which training examples most contribute to a given behavior? Influence functions aim to answer a counterfactual: how would the model’s parameters (and hence its outputs) change if a given sequence were added to the training set? While influence functions have produced insights for small models, they are difficult to scale to large language models (LLMs) due to the difficulty of computing an inverse-Hessian-vector product (IHVP). We use the Eigenvalue-corrected Kronecker-Factored Approximate Curvature (EK-FAC) approximation to scale influence functions up to LLMs with up to 52 billion parameters. In our experiments, EK-FAC achieves similar accuracy to traditional influence function estimators despite the IHVP computation being orders of magnitude faster. We investigate two algorithmic techniques to reduce the cost of computing gradients of candidate training sequences: TF-IDF filtering and query batching. We use influence functions to investigate the generalization patterns of LLMs, including the sparsity of the influence patterns, increasing abstraction with scale, math and programming abilities, cross-lingual generalization, and role-playing behavior. Despite many apparently sophisticated forms of generalization, we identify a surprising limitation: influences decay to near-zero when the order of key phrases is flipped. Overall, influence functions give us a powerful new tool for studying the generalization properties of LLMs. ∗. Core Research Contributors (Equal Contributions). †. University of Toronto and Vector Institute. ‡. Core Infrastructure Contributor. All authors are at Anthropic. Correspondence to: roger@anthropic.com .arXiv:2308.03296v1 [cs.LG] 7 Aug 2023
journal.pone.0262314.pdf
RESEA RCH ARTICL E Limits todetecting epistasis inthefitness landscape ofHIV Avik Biswas ID 1,2,Allan Haldane ID 1,2,Ronald M.Levy ID 1,2,3* 1Department ofPhysics, Temple University ,Philadelph ia,PA,United States ofAmerica, 2Center for Biophysics andComputationa lBiology ,Temple Univers ity,Philadelph ia,PA,United States ofAmerica, 3Department ofChemistry ,Temple Univers ity,Philadelph ia,PA,United States ofAmerica *ronlevy@ temple.ed u Abstract Therapid evolution ofHIVisconstrained byinteractions between mutations which affect viralfitness. Inthiswork, weexplore theroleofepistasis indetermining themutational fit- ness landscape ofHIVformultiple drug target proteins, including Protease, Reverse Tran- scriptase, andIntegrase. Epistatic interactions between residues modulate themutation patterns involved indrug resistance, withunambiguous signatures ofepistasis bestseen in thecomparison ofthePotts model predicted andexperimental HIVsequence “prevalences” expressed ashigher-order marginals (beyond triplets) ofthesequence probability distribu- tion.Incontrast, experimental measures offitness such asviralreplicative capacities gener- allyprobe fitness effects ofpoint mutations inasingle background, providing weak evidence forepistasis inviralsystems. Thedetectable effects ofepistasis areobscured byhigher evo- lutionary conservati onatsites. While double mutant cycles inprinciple, provide oneofthe bestways toprobe epistatic interactions experimentally without reference toaparticular background, weshow thattheanalysis iscomplicated bythesmall dynamic range ofmea- surements. Overall, weshow thatglobal pairwise interaction Potts models arenecessary for predicting themutational landscape ofviralproteins. Introduction Amajor challenge inbiological research, clinical medicine, and biotechnology ishow todeci- pher and exploit theeffects ofmutations [1].Inefforts ranging from theidentification of genetic variations underlying disease-causing mutations, totheunderstanding ofthegeno- type-phenotype mapping, todevelopment ofmodified proteins with useful properties, there is aneed torapidly assess thefunctional effects ofmutations. Experimental techniques toassess theeffect ofmultiple mutations onphenotype have been effective [2–5], butfunctional assays totestallpossible combinations arenotpossible duetothevast sizeofthemutational land- scape. Recent advances inbiotechnology have enabled deep mutational scans [6]and multi- plexed assays [7]foramore complete description ofthemutational landscapes ofafew proteins, butremain resource intensive and limited inscalability. The measured phenotypes depend onthetype ofexperiment and aresusceptible tochanges inexperimental conditions PLOS ONE PLOS ONE |https://doi.or g/10.137 1/journal.po ne.02623 14January 18,2022 1/22a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Biswas A,Haldane A,Levy RM(2022) Limits todetecting epistasis inthefitness landscape ofHIV.PLoS ONE17(1): e0262314. https://do i.org/10.1371/j ournal.pone .0262314 Editor: Emilio Gallicchio, Brooklyn College ofthe CityUniversity ofNewYork, UNITED STATES Received: October 15,2021 Accepted: December 20,2021 Published: January 18,2022 Peer Review History: PLOS recognize sthe benefits oftranspar ency inthepeer review process; therefore, weenable thepublication of allofthecontent ofpeer review andauthor response salongside final, published articles. The editorial history ofthisarticle isavailable here: https://doi.o rg/10.1371/jo urnal.pone.0 262314 Copyright: ©2022 Biswas etal.Thisisanopen access article distributed under theterms ofthe Creative Commons Attribution License, which permits unrestricte duse,distribu tion,and reproduction inanymedium, provided theoriginal author andsource arecredited. Data Availabilit yStatement: Thecode used for model inferenc eandassociated utilities ispublicly available through Haldane etal.,2020 (https://doi. org/10.1016 /j.cpc.2020.1 07312). HIVprotein sequences ,including sequence alignments, consensus sequen ces,etc.areobtained from the
2308.06259.pdf
Self-Alignment with Instruction Backtranslation Xian Li Ping Yu Chunting Zhou Timo Schick Luke Zettlemoyer Omer Levy Jason Weston Mike Lewis Meta AI Abstract We present a scalable method to build a high quality instruction following language model by automatically labelling human-written text with corresponding instruc- tions. Our approach, named instruction backtranslation , starts with a language model finetuned on a small amount of seed data, and a given web corpus. The seed model is used to construct training examples by generating instruction prompts for web documents ( self-augmentation ), and then selecting high quality examples from among these candidates ( self-curation ). This data is then used to finetune a stronger model. Finetuning LLaMa on two iterations of our approach yields a model that outperforms all other LLaMa-based models on the Alpaca leaderboard not relying on distillation data, demonstrating highly effective self-alignment. 1 Introduction Aligning large language models (LLMs) to perform instruction following typically requires finetuning on large amounts of human-annotated instructions or preferences [Ouyang et al., 2022, Touvron et al., 2023, Bai et al., 2022a] or distilling outputs from more powerful models [Wang et al., 2022a, Honovich et al., 2022, Taori et al., 2023, Chiang et al., 2023, Peng et al., 2023, Xu et al., 2023]. Recent work highlights the importance of human-annotation data quality Zhou et al. [2023], Köpf et al. [2023]. However, annotating instruction following datasets with such quality is hard to scale. In this work, we instead leverage large amounts of unlabelled data to create a high quality instruction tuning dataset by developing an iterative self-training algorithm. The method uses the model itself to both augment and curate high quality training examples to improve its own performance. Our approach, named instruction backtranslation , is inspired by the classic backtranslation method from machine translation, in which human-written target sentences are automatically annotated with model-generated source sentences in another language [Sennrich et al., 2015]. Our method starts with a seed instruction following model and a web corpus. The model is first used toself-augment its training set: for each web document, it creates an instruction following training example by predicting a prompt (instruction) that would be correctly answered by (a portion of) that document. Directly training on such data (similarly to Köksal et al. [2023]) gives poor results in our experiments, both because of the mixed quality of human written web text, and noise in the generated instructions. To remedy this, we show that the same seed model can be used to self-curate the set of newly created augmentation data by predicting their quality, and can then be self-trained on only the highest quality (instruction, output) pairs. The procedure is then iterated, using the improved model to better curate the instruction data, and re-training to produce a better model. Our resulting model, Humpback , outperforms all other existing non-distilled models on the Alpaca leaderboard Li et al. [2023]. Overall, instruction backtranslation is a scalable method for enabling language models to improve their own ability to follow instructions.arXiv:2308.06259v2 [cs.CL] 14 Aug 2023
2309.00267.pdf
RLAIF: Scaling Reinforcement Learning from Human Feedback with AI Feedback Harrison Lee, Samrat Phatale, Hassan Mansoor, Kellie Lu, Thomas Mesnard, Colton Bishop, Victor Carbune, Abhinav Rastogi Google Research {harrisonlee,samratph,hassan}@google.com Abstract Reinforcement learning from human feedback (RLHF) is effective at aligning large language models (LLMs) to human preferences, but gath- ering high-quality human preference labels is a key bottleneck. We conduct a head-to-head comparison of RLHF vs. RL from AI Feed- back (RLAIF) - a technique where preferences are labeled by an off-the-shelf LLM in lieu of humans, and we find that they result in similar improvements. On the task of summarization, human evaluators prefer generations from both RLAIF and RLHF over a baseline supervised fine-tuned model in ∼70% of cases. Further- more, when asked to rate RLAIF vs. RLHF summaries, humans prefer both at equal rates. These results suggest that RLAIF can yield human-level performance, offering a potential solution to the scalability limitations of RLHF. 1 Introduction Reinforcement Learning from Human Feedback (RLHF) is an effective technique for aligning lan- guage models to human preferences (Stiennon et al., 2020; Ouyang et al., 2022) and is cited as one of the key drivers of success in modern conver- sational language models like ChatGPT and Bard (Liu et al., 2023; Manyika, 2023). By training with reinforcement learning (RL), language mod- els can be optimized on complex, sequence-level objectives that are not easily differentiable with traditional supervised fine-tuning. The need for high-quality human labels is an obstacle for scaling up RLHF, and one natural question is whether artificially generated labels can achieve comparable results. Several works have shown that large language models (LLMs) exhibit a high degree of alignment with human judgment - even outperforming humans on some tasks (Gilardi et al., 2023; Ding et al., 2023). Bai et al. (2022b) was the first to explore using AI preferences to train a reward model used for RL fine-tuning - a Figure 1: Human evaluators strongly prefer RLHF and RLAIF summaries over the supervised fine-tuned (SFT) baseline. The differences in win rates between RLAIF vs. SFT andRLHF vs. SFT are not statistically significant. Additionally, when compared head-to-head, RLAIF is equally preferred to RLHF by human evaluators. Error bars denote 95% confidence intervals. technique called "Reinforcement Learning from AI Feedback" (RLAIF)1. While they showed that utilizing a hybrid of human and AI preferences in conjunction with the "Constitutional AI" self- revision technique outperforms a supervised fine- tuned baseline, their work did not directly compare the efficacy of human vs. AI feedback, leaving the question unanswered whether RLAIF can be a suitable alternative to RLHF. In this work, we directly compare RLAIF against RLHF on the task of summarization. Given a text and two candidate responses, we assign a prefer- ence label using an off-the-shelf LLM. We then train a reward model (RM) on the LLM prefer- ences with a contrastive loss. Finally, we fine-tune a policy model with reinforcement learning, using 1We use "RLAIF" to denote training a reward model on AI- labeled preferences followed by conducting RL fine-tuning. This is distinct from "Constitutional AI", which improves upon a supervised learning model through iteratively asking an LLM to generate better responses according to a constitution. Both were introduced in Bai et al. (2022b) and are sometimes confused for one another.arXiv:2309.00267v1 [cs.CL] 1 Sep 2023
big-book-of-mlops-2nd-edition-v2-102723-final.pdf
22 NDND EDITIONEDITION The Big Book of MLOpseBook NOW INCLUDING A SECTION ON LLMOPS JOSEPH BRADLEY | RAFI KURLANSIK | MATT THOMSON | NIALL TURBITTMODELOPS DATAOPS DEVOPS
codellama.pdf
Code Llama: Open Foundation Models for Code Baptiste Rozière†, Jonas Gehring†, Fabian Gloeckle†,∗, Sten Sootla†, Itai Gat, Xiaoqing Ellen Tan, Yossi Adi, Jingyu Liu, Tal Remez, Jérémy Rapin, Artyom Kozhevnikov, Ivan Evtimov, Joanna Bitton, Manish Bhatt, Cristian Canton Ferrer, Aaron Grattafiori, Wenhan Xiong, Alexandre Défossez, Jade Copet, Faisal Azhar, Hugo Touvron, Louis Martin, Nicolas Usunier, Thomas Scialom, Gabriel Synnaeve† Meta AI Abstract We release Code Llama , a family of large language models for code based on Llama 2 providing state-of-the-art performance among open models, infilling capabilities, support for large input contexts, and zero-shot instruction following ability for programming tasks. We provide multiple flavors to cover a wide range of applications: foundation models (Code Llama ), Python specializations ( Code Llama - Python ), and instruction-following models ( Code Llama - Instruct ) with 7B, 13B and 34B parameters each. All models are trained on sequences of 16k tokens and show improvements on inputs with up to 100k tokens. 7B and 13B Code Llama andCode Llama - Instruct variants support infilling based on surrounding content. Code Llama reaches state-of-the-art performance among open models on several code benchmarks, with scores of up to 53% and 55% on HumanEval and MBPP, respectively. Notably, Code Llama - Python 7B outperforms Llama 2 70B on HumanEval and MBPP, and all our models outperform every other publicly available model on MultiPL-E. We release Code Llama under a permissive license that allows for both research and commercial use.1 1 Introduction Large language models (LLMs) power a rapidly increasing number of applications, having reached a proficiency in natural language that allows them to be commanded and prompted to perform a variety of tasks (OpenAI, 2023; Touvron et al., 2023b). By utilizing large, in-domain datasets, their efficacy can be greatly improved for applications that require a combination of both natural and domain-specific language and understanding of specialized terminology. By training on domain-specific datasets, they have proved effective more broadly on applications that require advanced natural language understanding. A prominent use-case is the formal interaction with computer systems, such as program synthesis from natural language specifications, code completion, debugging, and generating documentation (for a survey, see Xu & Zhu, 2022, also see Section 5). In this work, we present Code Llama , a family of LLMs for code generation and infilling derived from Llama 2 (Touvron et al., 2023b) and released under the same custom permissive license. We provide inference code for both completion and infilling models in the accompanying repository.1Our approach is based on gradually specializing and increasing the capabilities of Llama 2 models by applying a cascade of training and fine-tuning steps (Figure 2): •Code-training from foundation models. While most LLMs for code generation such as AlphaCode (Li et al., 2022), InCoder (Fried et al., 2023) or StarCoder (Li et al., 2023) are trained on code only, Codex (Chen et al., 2021) was fine-tuned from a general language model. We also start from a foundation model ( Llama 2 , Touvron et al., 2023b) pretrained on general-purpose text and code data. Our comparison (Section 3.4.1) shows that initializing our model with Llama 2 outperforms the same architecture trained on code only for a given budget. 1https://github.com/facebookresearch/codellama †: Core contributors ∗: Meta AI, CERMICS École des Ponts ParisTech 1
2310.16764.pdf
2023-10-26 ConvNets Match Vision Transformers at Scale Samuel L Smith1, Andrew Brock1, Leonard Berrada1and Soham De1 1Google DeepMind Many researchers believe that ConvNets perform well on small or moderately sized datasets, but are not competitive with Vision Transformers when given access to datasets on the web-scale. We challenge this belief by evaluating a performant ConvNet architecture pre-trained on JFT-4B, a large labelled dataset of images often used for training foundation models. We consider pre-training compute budgets between 0.4k and 110k TPU-v4 core compute hours, and train a series of networks of increasing depth and width from the NFNet model family. We observe a log-log scaling law between held out loss and compute budget. After fine-tuning on ImageNet, NFNets match the reported performance of Vision Transformers with comparable compute budgets. Our strongest fine-tuned model achieves a Top-1 accuracy of 90.4 %. Keywords: ConvNets, CNN, Convolution, Transformer, Vision, ViTs, NFNets, JFT, Scaling, Image Introduction Convolutional Neural Networks (ConvNets) were responsible for many of the early successes of deep learning. Deep ConvNets were first de- ployed commercially over 20 years ago (Le- Cun et al., 1998), while the success of AlexNet on the ImageNet challenge in 2012 re-ignited widespread interest in the field (Krizhevsky et al., 2017). For almost a decade ConvNets (typically ResNets (He et al., 2016a,b)) dominated com- putervisionbenchmarks. Howeverinrecentyears they have increasingly been replaced by Vision Transformers (ViTs) (Dosovitskiy et al., 2020). Simultaneously, the computer vision commu- nity has shifted from primarily evaluating the performance of randomly initialized networks on specific datasets like ImageNet, to evaluat- ing the performance of networks pre-trained on large general purpose datasets collected from the web. This raises an important question; do Vision Transformers outperform ConvNet architectures pre-trained with similar computational budgets? Although most researchers in the community believe Vision Transformers show better scaling properties than ConvNets, there is surprisingly little evidence to support this claim. Many papers studying ViTs compare to weak ConvNet base- lines (typically the original ResNet architecture (Heetal.,2016a)). Additionally,thestrongestViT models have been pre-trained using large com-pute budgets beyond 500k TPU-v3 core hours (Zhai et al., 2022), which significantly exceeds the compute used to pre-train ConvNets. WeevaluatethescalingpropertiesoftheNFNet model family (Brock et al., 2021), a pure con- volutional architecture published concurrently with the first ViT papers, and the last ConvNet to set a new SOTA on ImageNet. We do not make any changes to the model architecture or the training procedure (beyond tuning simple hyper-parameters such as the learning rate or epoch budget). We consider compute budgets up to a maximum of 110k TPU-v4 core hours,1 and pre-train on the JFT-4B dataset which con- tains roughly 4 billion labelled images from 30k classes (Sun et al., 2017). We observe a log-log scaling law between validation loss and the com- pute budget used to pre-train the model. After fine-tuningonImageNet, ournetworksmatchthe performance of pre-trained ViTs with comparable compute budgets (Alabdulmohsin et al., 2023; Zhai et al., 2022), as shown in Figure 1. Pre-trained NFNets obey scaling laws We train a range of NFNet models of varying depthandwidthonJFT-4B.Eachmodelistrained for a range of epoch budgets between 0.25 and 8, using a cosine decay learning rate schedule. 1TPU-v4 cores have roughly double the theoretical flops of TPU-v3 cores, however both cores have similar memory. Corresponding author(s): slsmith@google.com ©2023 Google DeepMind. All rights reservedarXiv:2310.16764v1 [cs.CV] 25 Oct 2023
1912.10702.pdf
The Usual Suspects? Reassessing Blame for VAE Posterior Collapse Bin Dai daib13@mails.tsinghua.edu.cn Institute for Advanced Study Tsinghua University Beijing, China Ziyu Wang wzy196@gmail.com> Department of Computer Science and Technology Tsinghua University Beijing, China David Wipf davidwipf@gmail.com Microsoft Research Beijing, China Abstract In narrow asymptotic settings Gaussian VAE models of continuous data have been shown to possess global optima aligned with ground-truth distributions. Even so, it is well known that poor solutions whereby the latent posterior collapses to an uninformative prior are sometimes obtained in practice. However, contrary to conventional wisdom that largely assigns blame for this phenomena on the undue influence of KL-divergence regularization, we will argue that posterior collapse is, at least in part, a direct consequence of bad local minima inherent to the loss surface of deep autoencoder networks. In particular, we prove that even small nonlinear perturbations of affine VAE decoder models can produce such minima, and in deeper models, analogous minima can force the VAE to behave like an aggressive truncation operator, provably discarding information along all latent dimensions in certain circumstances. Regardless, the underlying message here is not meant to undercut valuable existing explanations of posterior collapse, but rather, to refine the discussion and elucidate alternative risk factors that may have been previously underappreciated. 1. Introduction The variational autoencoder (VAE) (Kingma & Welling, 2014; Rezende et al., 2014) repre- sents a powerful generative model of data points that are assumed to possess some complex yet unknown latent structure. This assumption is instantiated via the marginalized distri- bution pθ(x) =∫ pθ(x|z)p(z)dz, (1) which forms the basis of prevailing VAE models. Here z∈Rκis a collection of unobservable latent factors of variation that, when drawn from the prior p(z), are colloquially said to generate an observed data point x∈Rdthrough the conditional distribution pθ(x|z). The latter is controlled by parameters θthat can, at least conceptually speaking, be optimized by maximum likelihood over pθ(x) given available training examples. 1arXiv:1912.10702v1 [cs.LG] 23 Dec 2019
10.1038.s41586-024-07177-7.pdf
880 | Nature | Vol 627 | 28 March 2024 ArticleEvolutionary trajectories of small cell lung cancer under therapy Julie George1,2 ✉, Lukas Maas1, Nima Abedpour1,3,4, Maria Cartolano1,5, Laura Kaiser1, Rieke N. Fischer6, Andreas H. Scheel7, Jan-Philipp Weber6, Martin Hellmich8, Graziella Bosco1, Caroline Volz3,5, Christian Mueller1,2, Ilona Dahmen1, Felix John6, Cleidson Padua Alves1, Lisa Werr1, Jens Peter Panse9,10, Martin Kirschner9,10, Walburga Engel-Riedel11, Jessica Jürgens11, Erich Stoelben12, Michael Brockmann13, Stefan Grau14,15, Martin Sebastian16,17,18, Jan A. Stratmann16,17, Jens Kern19, Horst-Dieter Hummel20, Balazs Hegedüs21, Martin Schuler18,22, Till Plönes22,23, Clemens Aigner21,24, Thomas Elter3, Karin Toepelt3, Yon-Dschun Ko25, Sylke Kurz26, Christian Grohé26, Monika Serke27, Katja Höpker28, Lars Hagmeyer29, Fabian Doerr21,30, Khosro Hekmath30, Judith Strapatsas31, Karl-Otto Kambartel32, Geothy Chakupurakal33, Annette Busch34, Franz-Georg Bauernfeind34, Frank Griesinger35, Anne Luers35, Wiebke Dirks35, Rainer Wiewrodt36, Andrea Luecke36, Ernst Rodermann37, Andreas Diel37, Volker Hagen38, Kai Severin39, Roland T . Ullrich3,5, Hans Christian Reinhardt40,41, Alexander Quaas7, Magdalena Bogus42, Cornelius Courts42, Peter Nürnberg43, Kerstin Becker43, Viktor Achter44, Reinhard Büttner7, Jürgen Wolf6, Martin Peifer1,5 ✉ & Roman K. Thomas1,7,18 ✉ The evolutionary processes that underlie the marked sensitivity of small cell lung cancer (SCLC) to chemotherapy and rapid relapse are unknown1–3. Here we determined tumour phylogenies at diagnosis and throughout chemotherapy and immunotherapy by multiregion sequencing of 160 tumours from 65 patients. Treatment-naive SCLC exhibited clonal homogeneity at distinct tumour sites, whereas first-line platinum- based chemotherapy led to a burst in genomic intratumour heterogeneity and spatial clonal diversity. We observed branched evolution and a shift to ancestral clones underlying tumour relapse. Effective radio- or immunotherapy induced a re-expansion of founder clones with acquired genomic damage from first-line chemotherapy. Whereas TP53 and RB1 alterations were exclusively part of the common ancestor, MYC family amplifications were frequently not constituents of the founder clone. At relapse, emerging subclonal mutations affected key genes associated with SCLC biology, and tumours harbouring clonal CREBBP/ EP300 alterations underwent genome duplications. Gene-damaging TP53 alterations and co-alterations of TP53 missense mutations with TP73, CREBBP/ EP300 or FMN2 were significantly associated with shorter disease relapse following chemotherapy. In summary, we uncover key processes of the genomic evolution of SCLC under therapy, identify the common ancestor as the source of clonal diversity at relapse and show central genomic patterns associated with sensitivity and resistance to chemotherapy. Small cell lung cancer (SCLC) is one of the deadliest human cancers, with a 5 year survival rate of less than 7%1–4. The standard of care for extensive-stage SCLC consists of systemic treatment with platinum and etoposide, recently combined with programmed death-ligand 1 (PD-L1) immune checkpoint inhibitors (ICIs)2. One peculiarity of SCLC is its typically high sensitivity to platinum-based chemotherapy followed by rapid recurrence, which distinguishes it from most other human cancers. Unfortunately, second-line treatment with other chemothera - peutics or immunotherapy is only marginally effective and patients ultimately succumb to their disease1,2, 4. We and others have previously performed large-scale genome sequencing to comprehensively characterize cancer genome alterations in SCLC, which showed universal biallelic losses of the tumour sup - pressors TP53 and RB1, additional alterations to histone-modifying enzymes and cell cycle regulators, and MYC transcription factor ampli - fications5–7. Furthermore, SCLC subgroups were defined on the basis of the expression of neuroendocrine lineage transcription factors, which impact tumour biology and treatment outcome4,8,9. Finally, preliminary studies have provided initial clues in regard to molecular pathways associated with resistance to chemotherapy10,11. Despite progress in characterization of the molecular basis of SCLC, the underlying patterns of clonal evolution and the mechanisms caus - ing drug resistance have remained unclear. We suggest that cancer genome alterations not only drive malignant transformation in SCLC https://doi.org/10.1038/s41586-024-07177-7 Received: 25 January 2023 Accepted: 7 February 2024 Published online: 13 March 2024 Open access Check for updates A list of affiliations appears at the end of the paper.
2403.03507.pdf
GaLore: Memory-Efficient LLM Training by Gradient Low-Rank Projection Jiawei Zhao1Zhenyu Zhang3Beidi Chen2 4Zhangyang Wang3Anima Anandkumar* 1Yuandong Tian* 2 Abstract Training Large Language Models (LLMs) presents significant memory challenges, predom- inantly due to the growing size of weights and optimizer states. Common memory-reduction approaches, such as low-rank adaptation (LoRA), add a trainable low-rank matrix to the frozen pre-trained weight in each layer, reducing trainable parameters and optimizer states. However, such approaches typically underperform training with full-rank weights in both pre-training and fine-tuning stages since they limit the parameter search to a low-rank subspace and alter the training dynamics, and further, may require full-rank warm start. In this work, we propose Gradient Low-Rank Projec- tion ( GaLore ), a training strategy that allows full-parameter learning but is more memory- efficient than common low-rank adaptation methods such as LoRA. Our approach reduces memory usage by up to 65.5% in optimizer states while maintaining both efficiency and performance for pre-training on LLaMA 1B and 7B architectures with C4 dataset with up to 19.7B tokens, and on fine-tuning RoBERTa on GLUE tasks. Our 8-bit GaLore further reduces optimizer memory by up to 82.5% and total training memory by 63.3%, compared to a BF16 baseline. Notably, we demonstrate, for the first time, the feasibility of pre-training a 7B model on consumer GPUs with 24GB memory (e.g., NVIDIA RTX 4090) without model parallel, checkpointing, or offloading strategies. 1. Introduction Large Language Models (LLMs) have shown impressive performance across multiple disciplines, including conver- sational AI and language translation. However, pre-training *Equal advising1California Institute of Technology2Meta AI 3University of Texas at Austin4Carnegie Mellon University. Cor- respondence to: Jiawei Zhao <jiawei@caltech.edu >, Yuandong Tian<yuandong@meta.com >. Preprint. Work in Progress Memory Cost (GB)BF16 Adafactor 8-bit Adam 8-bit GaLore RTX 4090Figure 1: Memory consumption of pre-training a LLaMA 7B model with a token batch size of 256 on a single device, without activation checkpointing and memory offloading. Details refer to Section 5.5. Algorithm 1: GaLore, PyTorch-like for weight in model.parameters(): grad = weight.grad # original space -> compact space lorgrad = project (grad) # update by Adam, Adafactor, etc. lorupdate = update (lor grad) # compact space -> original space update = project back (lor update) weight.data += update and fine-tuning LLMs require not only a huge amount of computation but is also memory intensive. The memory requirements include not only billions of trainable parame- ters, but also their gradients and optimizer states (e.g., gra- dient momentum and variance in Adam) that can be larger than parameter storage themselves (Raffel et al., 2023; Touvron et al., 2023; Chowdhery et al., 2022). For exam- ple, pre-training a LLaMA 7B model from scratch with a single batch size requires at least 58 GB memory (14GB for trainable parameters, 42GB for Adam optimizer states and weight gradients, and 2GB for activations1). This makes the training not feasible on consumer-level GPUs such as NVIDIA RTX 4090 with 24GB memory. In addition to engineering and system efforts, such as gra- dient checkpointing (Chen et al., 2016), memory offload- ing (Rajbhandari et al., 2020), etc., to achieve faster and more efficient distributed training, researchers also seek to develop various optimization techniques to reduce the memory usage during pre-training and fine-tuning. 1The calculation is based on LLaMA architecture, BF16 nu- merical format, and maximum sequence length of 2048. 1arXiv:2403.03507v1 [cs.LG] 6 Mar 2024
2404.09932.pdf
Foundational Challenges in Assuring Alignment and Safety of Large Language Models Usman Anwar1 Abulhair Saparov∗2, Javier Rando∗3, Daniel Paleka∗3, Miles Turpin∗2, Peter Hase∗4, Ekdeep Singh Lubana∗5, Erik Jenner∗6, Stephen Casper∗7, Oliver Sourbut∗8, Benjamin L. Edelman∗9, Zhaowei Zhang∗10, Mario Günther∗11, Anton Korinek∗12, Jose Hernandez-Orallo∗13 Lewis Hammond8, Eric Bigelow9, Alexander Pan6, Lauro Langosco1, Tomasz Korbak14, Heidi Zhang15, Ruiqi Zhong6, Seán Ó hÉigeartaigh‡1, Gabriel Recchia16, Giulio Corsi‡1, Alan Chan‡17, Markus Anderljung‡17, Lilian Edwards‡18 Yoshua Bengio‡19, Danqi Chen‡20, Samuel Albanie‡1, Tegan Maharaj‡21, Jakob Foerster‡8, Florian Tramer‡3, He He‡2, Atoosa Kasirzadeh‡22, Yejin Choi‡23 David Krueger‡1 ∗indicates major contribution. ‡indicates advisory role. 1University of Cambridge2New York University3ETH Zurich4UNC Chapel Hill 5University of Michigian6University of California, Berkeley7Massachusetts Institute of Technology 8University of Oxford9Harvard University10Peking University11LMU Munich 12University of Virginia13Universitat Politècnica de València14University of Sussex 15Stanford University16Modulo Research17Center for the Governance of AI 18Newcastle University19Mila - Quebec AI Institute, Université de Montréal20Princeton University 21University of Toronto22University of Edinburgh23University of Washington, Allen Institute for AI Abstract This work identifies 18foundational challenges in assuring the alignment and safety of large language models (LLMs). These challenges are organized into three different categories: scientific understanding of LLMs ,development and deployment methods , andsociotechnical challenges . Based on the identified challenges, we pose 200 +concrete research questions. Corresponding author: Usman Anwar « usmananwar391@gmail.com » 1arXiv:2404.09932v1 [cs.LG] 15 Apr 2024
2022.naacl-main.134.pdf
Proceedings of the 2022 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies , pages 1836 - 1853 July 10-15, 2022 ©2022 Association for Computational Linguistics Intent Detection and Discovery from User Logs via Deep Semi-Supervised Contrastive Clustering Rajat Kumar, Mayur Patidar, Vaibhav Varshney, Lovekesh Vig, Gautam Shroff TCS Research, New Delhi, India {k.rajat2, patidar.mayur, varshney.v, lovekesh.vig, gautam.shroff}@tcs.com Abstract Intent Detection is a crucial component of Dia- logue Systems wherein the objective is to clas- sify a user utterance into one of the multiple pre-defined intents. A pre-requisite for devel- oping an effective intent identifier is a training dataset labeled with all possible user intents. However, even skilled domain experts are often unable to foresee all possible user intents at de- sign time and for practical applications, novel intents may have to be inferred incrementally on-the-fly from user utterances. Therefore, for any real-world dialogue system, the number of intents increases over time and new intents have to be discovered by analyzing the utter- ances outside the existing set of intents. In this paper, our objective is to i) detect known intent utterances from a large number of unlabeled utterance samples given a few labeled samples and ii) discover new unknown intents from the remaining unlabeled samples. Existing SOTA approaches address this problem via alternate representation learning and clustering wherein pseudo labels are used for updating the repre- sentations and clustering is used for generating the pseudo labels. Unlike existing approaches that rely on epoch-wise cluster alignment, we propose an end-to-end deep contrastive clus- tering algorithm that jointly updates model pa- rameters and cluster centers via supervised and self-supervised learning and optimally utilizes both labeled and unlabeled data. Our proposed approach outperforms competitive baselines on five public datasets for both settings: (i) where the number of undiscovered intents is known in advance, and (ii) where the number of intents is estimated by an algorithm. We also propose a human-in-the-loop variant of our approach for practical deployment which does not require an estimate of new intents and outperforms the end-to-end approach. 1 Introduction Modern dialogue systems (Louvan and Magnini, 2020) are increasingly reliant on intent detection I1: Activate My Card I2: Card LinkingUser -1​ U11: How do I link a new card in the app |I2|0.90|Pos U12: The ATM didnt return my card!​ |I2|0.10|Pos U13: The ATM machine ate my card.​ |I1|0.25|None U14: What do I do if my card is stolen?​ |I1|0.9|Neg U15: ​ Ineed to report a stolen card |I2|0.20|Neg U16: How is the weather today? |I2|0.10|None User -2 U21: Where do I go to add a new card?|I1|0.30|None U22: I want to activate my new card. |I1|0.95|None U23: The ATM sucked my card in. | I2| 0.20|Neg U24: My card has gone missing. |I1| 0.15 |None U25: My card was stolen |I2| 0.85|NoneU12, U13, U14, U15, U16, U21, U23, U24User utterances for Human Review U12 ,U13 ,U14 ,U15 U21, U23 ,U24, U16 I3: Card Lost or Stolen I4: Card Swallowed U16:OOSFigure 1: An instance of user logs, where the intent detection model is trained on two known intents, i.e., i1andi2. After manual analysis of user logs a human reviewer has discovered two new intents i3andi4and assigned utterance u21to an existing intent, i.e., i2. to classify a user utterance into one of the multiple known user intents. Intent detection is typically modeled as a multi-class classification problem where labeled data comprising of utterances for each known intent is manually created by domain experts. However, most real-world applications have to cope with evolving user needs and new functionality is routinely introduced into the dia- logue system resulting in a continuously increasing number of intents over time. Even for seasoned do- main experts estimating future user requirements at design time is challenging and these often have to be discovered from recent user logs which contain information corresponding to past user utterances, model response (i.e., predicted intent), implicit (confidence or softmax probability), and explicit (user clicks on a thumbs up or thumbs down icon) feedback as shown in Fig 1. The intent detection model presented in Fig. 1 is trained on two ini- tial intents ( I1,I2) from the banking domain using labeled data created by domain experts. Filtered user logs containing implicit and explicit feedback were shared with domain experts, who, discovered two new intents ( I3,I4) and mapped the filtered utterances to these new intents. Additionally, ex- perts also have to identify and discard utterances that are outside the domain of the dialog system.1836
8781_turing_complete_transformers_t.pdf
Under review as a conference paper at ICLR 2023 TURING COMPLETE TRANSFORMERS : T WOTRANS - FORMERS AREMORE POWERFUL THAN ONE Anonymous authors Paper under double-blind review ABSTRACT This paper presents Find+Replace transformers, a family of multi-transformer architectures that can provably do things no single transformer can, and which outperform GPT-4 on several challenging tasks. We first establish that tra- ditional transformers and similar architectures are not Turing complete, while Find+Replace transformers are. Using this fact, we show how arbitrary programs can be compiled to Find+Replace transformers, aiding interpretability research. We also demonstrate the superior performance of Find+Replace transformers over GPT-4 on a set of composition challenge problems (solving problems 20x longer on tower of Hanoi, 3%→100% on multiplication, 72%→100% on a dynamic programming problem). This work aims to provide a theoretical basis for multi- agent architectures, and to encourage their exploration. 1 I NTRODUCTION The first computers – including the difference engine , differential analyzer, Z1, and ABC (Bab- bage & Babbage, 1825; Bush, 1931; Rojas, 2014; Atanasoff, 1940) – were not Turing Complete. Some such machines, like the Hollerith Tabulating Machine (Hollerith, 1889) and the Harvard Mark I (Comrie, 1946), even achieved considerable real-world use despite that limitation. However, the advent of Turing Complete computers (Turing et al., 1936; Goldstine & Goldstine, 1946; Kilburn, 1949) fundamentally changed how computers were used and led to the development of more com- plex, comprehensible, and composable programs (Backus, 1954; Copeland, 2004). As we will show in this paper, current LLMs based on the transformer architecture (Vaswani et al., 2017) are not Turing Complete. We present an alternative that is. The fundamental reason transformers are not Turing complete is that, once the architecture of a transformer is decided, there is a bounded amount of computation that it can do. This guarantees the model will fail to generalize beyond input of some length and complexity. Such limitations are not only theoretical, they are supported by a number of recent results on the ability of language models to generalize to large context lengths (Del’etang et al., 2022; Liu et al., 2023; Dziri et al., 2023). Addressing these deficiencies is nontrivial and requires a fundamental shift in approach. We propose an approach drawing from multi-agent systems (Messing, 2003; Stone & Veloso, 2000), particularly multi-transformer systems. Such systems have recently garnered interest, being employed to gener- ate simulacra of human behavior (Park et al., 2023), perform economic simulations (Horton, 2023), and demonstrate open-ended exploration in games like Minecraft (Wang et al., 2023a). This paper presents a family of multi-transformer architectures, and provides theoretical and em- pirical evidence the family can outperform traditional transformers. We hope this study will ignite further investigations into architectures that are multi-transformer and Turing complete. Our contributions are as follows: • We provide a simple proof that current LLMs are not Turing Complete • We present Find+Replace transformers, a family of provably Turing Complete architectures • We introduce a method for turning any program into a Find+Replace transformer • We show that Find+Replace transformers out-perform GPT-4 on a set of challenge tasks 1
2023.01.11.523679v3.full.pdf
The Nucleotide Transformer: Building and Evaluating Robust Foundation Models for Human Genomics Hugo Dalla-Torre1, Liam Gonzalez1, Javier Mendoza-Revilla1, Nicolas Lopez Carranza1, Adam Henryk Grzywaczewski2, Francesco Oteri1, Christian Dallago2 3, Evan Trop1, Bernardo P. de Almeida1, Hassan Sirelkhatim2, Guillaume Richard1, Marcin Skwark1, Karim Beguir1, Marie Lopez∗†1, Thomas Pierrot∗†1 1InstaDeep2Nvidia3TUM Abstract Closing the gap between measurable genetic information and observable traits is a longstand- ing challenge in genomics. Yet, the prediction of molecular phenotypes from DNA sequences alone remains limited and inaccurate, often driven by the scarcity of annotated data and the inability to transfer learnings between prediction tasks. Here, we present an extensive study of foundation models pre-trained on DNA sequences, named the Nucleotide Transformer, rang- ing from 50M up to 2.5B parameters and integrating information from 3,202 diverse human genomes, as well as 850 genomes selected across diverse phyla, including both model and non- model organisms. These transformer models yield transferable, context-specific representations of nucleotide sequences, which allow for accurate molecular phenotype prediction even in low- data settings. We show that the developed models can be fine-tuned at low cost and despite low available data regime to solve a variety of genomics applications. Despite no supervision, the transformer models learned to focus attention on key genomic elements, including those that regulate gene expression, such as enhancers. Lastly, we demonstrate that utilizing model rep- resentations can improve the prioritization of functional genetic variants. The training and ap- plication of foundational models in genomics explored in this study provide a widely applicable stepping stone to bridge the gap of accurate molecular phenotype prediction from DNA sequence. Code and weights available at: https://github.com/instadeepai/nucleotide-transformer in Jax and https://huggingface.co/InstaDeepAI in Pytorch. Example notebooks to apply these models to any downstream task are available on HuggingFace. Introduction Foundation models in artificial intelligence (AI) are characterized by their large-scale nature, incorpo- rating millions of parameters trained on extensive datasets. These models can be adapted for a wide range of subsequent predictive tasks and have profoundly transformed the AI field. Notable examples in natural language processing (NLP) include the so-called language models (LMs) BERT [ 1] and GPT [2]. LMs have gained significant popularity in recent years owing to their ability to be trained on un- labeled data, creating general-purpose representations capable of solving downstream tasks. One way they achieve a comprehensive understanding of language is by solving billions of cloze tests, in which they predict the correct word to fill in the blank in a given sentence. This approach is known as masked language modeling [1]. Early instances of foundation models applying this objective to biology involved training LMs on protein sequences, where they were tasked with predicting masked amino acids in large protein sequence datasets [3, 4,5]. These protein LMs, when applied to downstream tasks using transfer learning, demonstrated the ability to compete with and even outperform previous methods for tasks such as predicting protein structure [3, 4] and function [6, 7], even in data scarce regiments [8]. ∗Equal Supervision †Corresponding authors: t.pierrot@instadeep.com & m.lopez@instadeep.com 1. CC-BY-ND 4.0 International license available under a(which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made The copyright holder for this preprint this version posted September 19, 2023. ; https://doi.org/10.1101/2023.01.11.523679doi: bioRxiv preprint
bengio03a.pdf
Journal of Machine Learning Research 3 (2003) 1137–1155 Submitted 4/02; Published 2/03 ANeural Probabilistic Language Model YoshuaBengio BENGIOY @IRO.UMONTREAL .CA Réjean Ducharme DUCHARME @IRO.UMONTREAL .CA Pascal Vincent VINCENTP @IRO.UMONTREAL .CA Christian Jauvin JAUVINC@IRO.UMONTREAL .CA Départementd’InformatiqueetRechercheOpérationnelle Centre deRechercheMathématiquesUniversité deMontréal,Montréal,Québec,Canada Editors:Jaz Kandola,ThomasHofmann,TomasoPoggioandJohnShawe-Taylor Abstract A goal of statistical language modeling is to learn the joint probability function of sequences of wordsin a language. Thisis intrinsically difficultbecause of the curse of dimensionality :aw o r d sequenceonwhichthemodelwillbetestedislikelytobedifferentfromallthewordsequencesseen duringtraining. Traditionalbutverysuccessfulapproachesbasedonn-gramsobtaingeneralization byconcatenatingveryshortoverlappingsequencesseeninthetrainingset. We proposetofightthe curse of dimensionality by learning a distributed representation for words which allows each training sentence to inform the model about an exponential number of semantically neighboringsentences. The model learns simultaneously (1) a distributed representation for each word along with (2) the probability function for word sequences, expressed in terms of these representations. Generalization is obtained because a sequence of words that has never been seen before gets highprobabilityifitismadeofwordsthataresimilar(inthesenseofhavinganearbyrepresentation)to wordsforminganalreadyseensentence. Trainingsuchlargemodels(withmillionsofparameters) within a reasonable time is itself a significant challenge. We report on experiments using neuralnetworks for the probability function, showing on two text corpora that the proposed approach significantlyimprovesonstate-of-the-artn-grammodels,andthattheproposedapproachallowsto takeadvantageoflongercontexts. Keywords: Statistical language modeling, artificial neural networks, distributed representation, curseofdimensionality 1. Introduction A fundamental problem that makes language modeling and other learning problems difficult is the curse of dimensionality . It is particularly obvious in the case when one wants to model the joint distribution between many discrete random variables (such as words in a sentence, or discrete at-tributes in a data-mining task). For example, if one wants to model the joint distribution of 10consecutive words in a natural language with a vocabulary Vof size 100,000, there are potentially 100000 10−1=1050−1 free parameters. When modeling continuous variables, we obtain gen- eralization more easily (e.g. with smooth classes of functions like multi-layer neural networks or Gaussian mixture models) because the function to be learned can be expected to have some lo-cal smoothness properties. For discrete spaces, the generalization structure is not as obvious: anychange of these discrete variables may have a drastic impact on the value of the function to be esti- c⃝2003 Yoshua Bengio, Réjean Ducharme, Pascal Vincent, Christian Jauvin.
2004.05150.pdf
Longformer: The Long-Document Transformer Iz Beltagy∗Matthew E. Peters∗Arman Cohan∗ Allen Institute for Artificial Intelligence, Seattle, WA, USA {beltagy,matthewp,armanc }@allenai.org Abstract Transformer-based models are unable to pro- cess long sequences due to their self-attention operation, which scales quadratically with the sequence length. To address this limitation, we introduce the Longformer with an attention mechanism that scales linearly with sequence length, making it easy to process documents of thousands of tokens or longer. Longformer’s attention mechanism is a drop-in replacement for the standard self-attention and combines a local windowed attention with a task moti- vated global attention. Following prior work on long-sequence transformers, we evaluate Longformer on character-level language mod- eling and achieve state-of-the-art results on text8 andenwik8 . In contrast to most prior work, we also pretrain Longformer and finetune it on a variety of downstream tasks. Our pretrained Longformer consistently out- performs RoBERTa on long document tasks and sets new state-of-the-art results on Wiki- Hop and TriviaQA. We finally introduce the Longformer-Encoder-Decoder (LED), a Long- former variant for supporting long document generative sequence-to-sequence tasks, and demonstrate its effectiveness on the arXiv sum- marization dataset.1 1 Introduction Transformers (Vaswani et al., 2017) have achieved state-of-the-art results in a wide range of natu- ral language tasks including generative language modeling (Dai et al., 2019; Radford et al., 2019) and discriminative language understanding (De- vlin et al., 2019). This success is partly due to the self-attention component which enables the net- work to capture contextual information from the entire sequence. While powerful, the memory and computational requirements of self-attention grow ∗Equal contribution. 1https://github.com/allenai/longformer Figure 1: Runtime and memory of full self- attention and different implementations of Long- former’s self-attention; Longformer-loop is non- vectorized, Longformer-chunk is vectorized, and Longformer-cuda is a custom cuda kernel im- plementations. Longformer’s memory usage scales linearly with the sequence length, unlike the full self-attention mechanism that runs out of memory for long sequences on current GPUs. Different implementations vary in speed, with the vectorized Longformer-chunk being the fastest. More details are in section 3.2. quadratically with sequence length, making it infea- sible (or very expensive) to process long sequences. To address this limitation, we present Long- former, a modified Transformer architecture with a self-attention operation that scales linearly with the sequence length, making it versatile for pro- cessing long documents (Fig 1). This is an advan- tage for natural language tasks such as long docu- ment classification, question answering (QA), and coreference resolution, where existing approaches partition or shorten the long context into smaller sequences that fall within the typical 512 token limit of BERT-style pretrained models. Such parti- tioning could potentially result in loss of important cross-partition information, and to mitigate this problem, existing methods often rely on complex architectures to address such interactions. On the other hand, our proposed Longformer is able to build contextual representations of the entire con- text using multiple layers of attention, reducing thearXiv:2004.05150v2 [cs.CL] 2 Dec 2020
2309.17453v4.pdf
Published as a conference paper at ICLR 2024 EFFICIENT STREAMING LANGUAGE MODELS WITH ATTENTION SINKS Guangxuan Xiao1∗Yuandong Tian2Beidi Chen3Song Han1,4Mike Lewis2 1Massachusetts Institute of Technology2Meta AI 3Carnegie Mellon University4NVIDIA https://github.com/mit-han-lab/streaming-llm ABSTRACT Deploying Large Language Models (LLMs) in streaming applications such as multi-round dialogue, where long interactions are expected, is urgently needed but poses two major challenges. Firstly, during the decoding stage, caching previous tokens’ Key and Value states (KV) consumes extensive memory. Secondly, popular LLMs cannot generalize to longer texts than the training sequence length. Window attention, where only the most recent KVs are cached, is a natural approach — but we show that it fails when the text length surpasses the cache size. We observe an interesting phenomenon, namely attention sink , that keeping the KV of initial tokens will largely recover the performance of window attention. In this paper, we first demonstrate that the emergence of attention sink is due to the strong attention scores towards initial tokens as a “sink” even if they are not semantically important. Based on the above analysis, we introduce StreamingLLM, an efficient framework that enables LLMs trained with a finite length attention window to generalize to infinite sequence length without any fine-tuning. We show that StreamingLLM can enable Llama-2, MPT, Falcon, and Pythia to perform stable and efficient language modeling with up to 4 million tokens and more. In addition, we discover that adding a placeholder token as a dedicated attention sink during pre-training can further improve streaming deployment. In streaming settings, StreamingLLM outperforms the sliding window recomputation baseline by up to 22.2 ×speedup. Code and datasets are provided in the link. 1 I NTRODUCTION Large Language Models (LLMs) (Radford et al., 2018; Brown et al., 2020; Zhang et al., 2022; OpenAI, 2023; Touvron et al., 2023a;b) are becoming ubiquitous, powering many natural language processing applications such as dialog systems (Schulman et al., 2022; Taori et al., 2023; Chiang et al., 2023), document summarization (Goyal & Durrett, 2020; Zhang et al., 2023a), code completion (Chen et al., 2021; Rozière et al., 2023) and question answering (Kamalloo et al., 2023). To unleash the full potential of pretrained LLMs, they should be able to efficiently and accurately perform long sequence generation. For example, an ideal ChatBot assistant can stably work over the content of recent day-long conversations. However, it is very challenging for LLM to generalize to longer sequence lengths than they have been pretrained on, e.g., 4K for Llama-2 Touvron et al. (2023b). The reason is that LLMs are constrained by the attention window during pre-training. Despite substantial efforts to expand this window size (Chen et al., 2023; kaiokendev, 2023; Peng et al., 2023) and improve training (Dao et al., 2022; Dao, 2023) and inference (Pope et al., 2022; Xiao et al., 2023; Anagnostidis et al., 2023; Wang et al., 2021; Zhang et al., 2023b) efficiency for lengthy inputs, the acceptable sequence length remains intrinsically finite , which doesn’t allow persistent deployments. In this paper, we first introduce the concept of LLM streaming applications and ask the question: Can we deploy an LLM for infinite-length inputs without sacrificing efficiency and performance? ∗Part of the work done during an internship at Meta AI. 1arXiv:2309.17453v4 [cs.CL] 7 Apr 2024
10.1101.2022.11.18.517004.pdf
High-resolution image reconstruction with latent diffusion models from human brain activity Yu Takagi1,2* Shinji Nishimoto1,2 1Graduate School of Frontier Biosciences, Osaka University, Japan 2CiNet, NICT, Japan {takagi.yuu.fbs,nishimoto.shinji.fbs} @osaka-u.ac.jp Figure 1. Presented images (red box, top row) and images reconstructed from fMRI signals (gray box, bottom row) for one subject (subj01). Abstract Reconstructing visual experiences from human brain ac- tivity offers a unique way to understand how the brain rep- resents the world, and to interpret the connection between computer vision models and our visual system. While deep generative models have recently been employed for thistask, reconstructing realistic images with high semantic fi-delity is still a challenging problem. Here, we propose a new method based on a diffusion model (DM) to recon- struct images from human brain activity obtained via func- tional magnetic resonance imaging (fMRI). More specifi-cally, we rely on a latent diffusion model (LDM) termedStable Diffusion. This model reduces the computationalcost of DMs, while preserving their high generative perfor- mance. We also characterize the inner mechanisms of the LDM by studying how its different components (such as thelatent vector of image Z, conditioning inputs C, and differ-ent elements of the denoising U-Net) relate to distinct brainfunctions. We show that our proposed method can recon- struct high-resolution images with high fidelity in straight- * Corresponding authorforward fashion, without the need for any additional train- ing and fine-tuning of complex deep-learning models. Wealso provide a quantitative interpretation of different LDM components from a neuroscientific perspective. Overall, our study proposes a promising method for reconstructing im-ages from human brain activity, and provides a new frame- work for understanding DMs. Please check out our web- page at https://sites.google.com/view/stablediffusion-with- brain/. 1. Introduction A fundamental goal of computer vision is to construct artificial systems that see and recognize the world as hu-man visual systems do. Recent developments in the mea- surement of population brain activity, combined with ad- vances in the implementation and design of deep neu-ral network models, have allowed direct comparisons be- tween latent representations in biological brains and ar- chitectural characteristics of artificial networks, providing important insights into how these systems operate [3, 8– 10,13,18,19,21,42,43,54,55]. These efforts have in- 1. CC-BY 4.0 International license available under a(which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made The copyright holder for this preprint this version posted March 11, 2023. ; https://doi.org/10.1101/2022.11.18.517004doi: bioRxiv preprint
2309.05444.pdf
Pushing Mixture of Experts to the Limit: Extremely Parameter Efficient MoE for Instruction Tuning Ted Zadouri Cohere for AI ted@cohere.comAhmet Üstün Cohere for AI ahmet@cohere.comArash Ahmadian† Cohere for AI arash@cohere.com Beyza Ermiş Cohere For AI beyza@cohere.comAcyr Locatelli Cohere acyr@cohere.comSara Hooker Cohere for AI sarahooker@cohere.com Abstract The Mixture of Experts (MoE) is a widely known neural architecture where an ensemble of specialized sub-models optimizes overall performance with a constant computational cost. However, conventional MoEs pose challenges at scale due to the need to store all experts in memory. In this paper, we push MoE to the limit. We propose extremely parameter-efficient MoE by uniquely combining MoE architecture with lightweight experts.Our MoE architecture outperforms standard parameter-efficient fine-tuning (PEFT) methods and is on par with full fine-tuning by only updating the lightweight experts – less than 1% of an 11B parameters model. Furthermore, our method generalizes to unseen tasks as it does not depend on any prior task knowledge. Our research underscores the versatility of the mixture of experts architecture, showcasing its ability to deliver robust performance even when subjected to rigorous parameter constraints. Our code used in all the experiments is publicly available here: https://github.com/for-ai/parameter-efficient-moe . 1 Introduction A conventional training paradigm is to apply the weights of a model to each input. Arguably, this is not efficient since a given input may not need all of a model’s capacity. In contrast, MoEs build on the premise that sub-modular components – so called experts – can specialize to different types of inputs. This emphasis on conditional computation has important efficiency side-effects such as constant inference cost. This has made MoEs an area of significant research and widespread adoption in the era of large-scale Transformers where scaling has increased deployment and latency costs (Shazeer et al., 2018; Riquelme et al., 2021; Du et al., 2022; Fedus et al., 2022). While the majority of work to-date has focused on MoEs as a pretraining strategy,the inherent motivation of MoEs is not confined solely to pretraining. In fact, the merits of MoEs are arguably well suited to an instruction fine-tuning setting where the data is often deliberately structured to †Also affiliated with the University of Toronto & the Vector Institute for Artificial Intelligence. Released as a preprint on September 12, 2023 1arXiv:2309.05444v1 [cs.CL] 11 Sep 2023
1506.05254.pdf
Gradient Estimation Using Stochastic Computation Graphs John Schulman1,2 joschu@eecs.berkeley.eduNicolas Heess1 heess@google.com Theophane Weber1 theophane@google.comPieter Abbeel2 pabbeel@eecs.berkeley.edu 1Google DeepMind2University of California, Berkeley, EECS Department Abstract In a variety of problems originating in supervised, unsupervised, and reinforce- ment learning, the loss function is defined by an expectation over a collection of random variables, which might be part of a probabilistic model or the exter- nal world. Estimating the gradient of this loss function, using samples, lies at the core of gradient-based learning algorithms for these problems. We introduce the formalism of stochastic computation graphs —directed acyclic graphs that in- clude both deterministic functions and conditional probability distributions—and describe how to easily and automatically derive an unbiased estimator of the loss function’s gradient. The resulting algorithm for computing the gradient estimator is a simple modification of the standard backpropagation algorithm. The generic scheme we propose unifies estimators derived in variety of prior work, along with variance-reduction techniques therein. It could assist researchers in developing in- tricate models involving a combination of stochastic and deterministic operations, enabling, for example, attention, memory, and control actions. 1 Introduction The great success of neural networks is due in part to the simplicity of the backpropagation al- gorithm, which allows one to efficiently compute the gradient of any loss function defined as a composition of differentiable functions. This simplicity has allowed researchers to search in the space of architectures for those that are both highly expressive and conducive to optimization; yield- ing, for example, convolutional neural networks in vision [12] and LSTMs for sequence data [9]. However, the backpropagation algorithm is only sufficient when the loss function is a deterministic, differentiable function of the parameter vector. A rich class of problems arising throughout machine learning requires optimizing loss functions that involve an expectation over random variables. Two broad categories of these problems are (1) likelihood maximization in probabilistic models with latent variables [17, 18], and (2) policy gradi- ents in reinforcement learning [5, 23, 26]. Combining ideas from from those two perennial topics, recent models of attention [15] and memory [29] have used networks that involve a combination of stochastic and deterministic operations. In most of these problems, from probabilistic modeling to reinforcement learning, the loss functions and their gradients are intractable, as they involve either a sum over an exponential number of latent variable configurations, or high-dimensional integrals that have no analytic solution. Prior work (see Section 6) has provided problem-specific derivations of Monte-Carlo gradient estimators, however, to our knowledge, no previous work addresses the general case. Appendix C recalls several classic and recent techniques in variational inference [14, 10, 21] and re- inforcement learning [23, 25, 15], where the loss functions can be straightforwardly described using 1arXiv:1506.05254v3 [cs.LG] 5 Jan 2016
10.1038.s41586-023-06832-9.pdf
832 | Nature | Vol 625 | 25 January 2024 ArticlePredicting multiple conformations via sequence clustering and AlphaFold2 Hannah K. Wayment-Steele1,7, Adedolapo Ojoawo1,7, Renee Otten1,5, Julia M. Apitz1, Warintra Pitsawong1,6, Marc Hömberger1,5, Sergey Ovchinnikov2, Lucy Colwell3,4 & Dorothee Kern1 ✉ AlphaFold2 (ref.  1) has revolutionized structural biology by accurately predicting single structures of proteins. However, a protein’s biological function often depends on multiple conformational substates2, and disease-causing point mutations often cause population changes within these substates3,4. We demonstrate that clustering a multiple-sequence alignment by sequence similarity enables AlphaFold2 to sample alternative states of known metamorphic proteins with high confidence. Using this method, named AF-Cluster, we investigated the evolutionary distribution of predicted structures for the metamorphic protein KaiB 5 and found that predictions of both conformations were distributed in clusters across the KaiB family. We used nuclear magnetic resonance spectroscopy to confirm an AF-Cluster prediction: a cyanobacteria KaiB variant is stabilized in the opposite state compared with the more widely studied variant. To test AF-Cluster’s sensitivity to point mutations, we designed and experimentally verified a set of three mutations predicted to flip KaiB from Rhodobacter sphaeroides from the ground to the fold-switched state. Finally, screening for alternative states in protein families without known fold switching identified a putative alternative state for the oxidoreductase Mpt53 in Mycobacterium tuberculosis. Further development of such bioinformatic methods in tandem with experiments will probably have a considerable impact on predicting protein energy landscapes, essential for illuminating biological function. Understanding the mechanistic basis of any protein’s functions requires understanding the complete set of conformational substates that it can adopt2. For any protein-structure prediction method, the task of predicting ensembles can be considered in two parts: an ideal method would (1) generate conformations encompassing the com - plete landscape and (2) score these conformations in accordance with the underlying Boltzmann distribution. AlphaFold2 (AF2) achieved breakthrough performance in the CASP14 competition6 in part by advancing the state of the art for inferring patterns of interactions between related sequences in a multiple-sequence alignment (MSA), building on a long history of methods for inferring these patterns7–10, often called evolutionary couplings. The premise of methods to infer structure based on evolutionary couplings is that, because amino acids exist and evolve in the context of 3D structure, they are not free to evolve independently, but instead co-evolve in patterns reflective of the underlying structure. However, proteins must evolve in the context of the multiple conformational states that they adopt. The high accuracy of AF2 (ref. 1 ) at single-structure prediction has garnered interest in its ability to predict multiple conformations of proteins, yet AF2 has been demonstrated to fail in predicting multiple structures of meta - morphic proteins11, proteins with apo/holo conformational changes12 and other multi-state proteins13 using its default settings. Despite these demonstrations of shortcomings, it was shown that subsampling the input MSA enables AF2 to predict known conformational changes of transporters14. Success of the MSA subsampling approach in a given system implies that when calculating evolutionary couplings with a complete MSA, evolutionary couplings for multiple states are already sufficiently present such that when introducing noise to obscure subsets of these contacts, there are still sufficiently complete sets of contacts cor - responding to one or the other state. Indeed, methods for inferring evolutionary couplings have already demonstrated that contacts corre - sponding to multiple states can be observed at the level of entire MSAs for membrane proteins15, ligand-induced conformational changes16 and multimerization-induced conformational changes17. Methods proposed to deconvolve sets of states when previous knowledge about one or more states is known include ablating residues corresponding to contacts of a known dominant state18 and supplementing the original MSA with proteins that are known to occupy a rarer state19. However, there is a need for methods that deconvolve signal from multiple states if they are not already both present at the level of the entire MSA. For example, simply subdividing a MSA and making predictions for por - tions of the MSA has also been used to detect variations in evolutionary couplings within a protein family17,20.https://doi.org/10.1038/s41586-023-06832-9 Received: 7 July 2023 Accepted: 3 November 2023 Published online: 13 November 2023 Open access Check for updates 1Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Waltham, MA, USA. 2Center for Systems Biology, Harvard University, Cambridge, MA, USA. 3Google Research, Cambridge, MA, USA. 4Cambridge University, Cambridge, UK. 5Present address: Treeline Biosciences, Watertown, MA, USA. 6Present address: Biomolecular Discovery, Relay Therapeutics, Cambridge, MA, USA. 7These authors contributed equally: Hannah K. Wayment-Steele, Adedolapo Ojoawo. ✉e-mail: dkern@brandeis.edu
GPSA-Supplementary-Information.pdf
Supplementary Information for: Generative Capacity of Probabilistic Protein Sequence Models Francisco McGee Sandro Hauri Quentin Novinger Slobodan Vucetic Ronald M. Levy Vincenzo Carnevale Allan Haldane Supplementary Note 1 - sVAE implementation The standard variational autoencoder (sVAE) is a deep, symmetrical, and undercomplete autoencoder neural network composed of a separate encoder qφ(Z|S)and decoder pθ(S|Z)1, which map input sequences Sinto regions of a low-dimensional latent space Zand back (see Fig. S1). It is a probabilistic model, and in our “vanilla”2 implementation we assume sequences will be distributed according to a unit normal distribution in latent space, p(Z) =N[0,1](Z)3. Training of a VAE can be understood as maximization of (the logarithm of) the dataset likelihood L=∏Spθ(S) =∑S∫pθ(S|Z)p(Z)dZwith the addition of a Kullback-Leibler regularization term DKL[qφ(Z|S),pθ(Z|S)], where pθ(Z|S)is the posterior of the decoder, which allows use of the fitted encoder qφ(Z|S)to perform efficient estimation of the likelihood and its gradient by Monte-Carlo sampling, for appropriate encoder models. The sVAE architecture is built on the same basic VAE architecture of “EVOVAE”4, which itself appears to be built on the VAE implementation provided by developers for the Keras library5, and this same VAE architecture is used for each protein presented in this work. Similarly to EVOVAE, sVAE’s hyperparameters were tuned using grid search. sVAE is composed of 3symmetrical ELU-activated layers in both the encoder and decoder, each layer with 250dense (fully-connected) nodes. The encoder and decoder are connected by a latent layer of lnodes, and we use l=7in the main text. We provide further justification for the selection of l=7elsewhere in the Supplementary Note 3. sVAE’s input layer accepts one-hot encoded sequences, the output layer is sigmoid-activated, and its node output values can be interpreted as a Bernoulli distribution of the same dimensions as a one-hot encoded sequence. The first layer of the encoder and the middle layer of the decoder have dropout regularization applied with 30% dropout rate, and the middle layer of the encoder uses batch normalization4,6,7. In all inferences, we hold out 10% of the training sequences as a validation dataset, and perform maximum likelihood optimization using the Keras Adam stochastic gradient optimizer on the remaining 90%8, using mini-batch gradient descent with a batch size of 200. After each training epoch we evaluate the loss function for the training and validation data subsets separately. We have tested using early-stopping regularization to stop inference once the validation loss has not decreased for three epochs in a row, as in previous implementations, but this led to some variability in the model depending on when the early stopping criterion was reached. To avoid this variability, and to make different models more directly comparable, we instead fixed the number of epochs to 32for all models, since in the early stopping tests this led to near minimum training loss and validation loss, and did not lead to significant overfitting as would be apparent from an increase in the validation loss. sVAE was implemented using Keras, building on previous implementations4,5, however with a modification of the loss function relative to both of these, to remove a scaling factor of Lqon the reconstruction loss, which is sometimes used to avoid issues with local minima as described further below. This prefactor leads to a non-unit variance of the latent space distribution of the dataset sequences, violating our definition that the latent space distribution should be normal with unit variance, p(Z) =N[0,1](Z). In the next section we show that after removing the prefactor the latent space distribution is approximately a unit normal, which more closely follows the original VAE conception3,9. Our implementation is available at https://github.com/ahaldane/MSA_VAE . To generate a sequence from the model we generate a random sample in latent space from the latent distribution N[0,1], and pass this value to the decoder to obtain a Bernoulli distribution, from which we sample once. 1/20
2402.04236.pdf
CogCoM: Train Large Vision-Language Models Diving into Details through Chain of Manipulations Ji Qi1‡Ming Ding2Weihan Wang1‡Yushi Bai1‡Qingsong Lv2Wenyi Hong1‡ Bin Xu1Lei Hou1Juanzi Li1Yuxiao Dong1Jie Tang1 qj20@mails.tsinghua.edu.cn, ming.ding@zhipuai.cn Abstract Vision-Language Models (VLMs) have demon- strated their widespread viability thanks to exten- sive training in aligning visual instructions to an- swers. However, this conclusive alignment leads models to ignore critical visual reasoning, and fur- ther result in failures on meticulous visual prob- lems and unfaithful responses. In this paper, we propose Chain of Manipulations , a mechanism that enables VLMs to solve problems with a se- ries of manipulations, where each manipulation refers to an operation on the visual input, either from intrinsic abilities ( e.g., grounding ) acquired through prior training or from imitating human- like behaviors ( e.g., zoom in ). This mechanism encourages VLMs to generate faithful responses with evidential visual reasoning, and permits users to trace error causes in the interpretable paths. We thus train CogCoM , a general 17B VLM with a memory-based compatible architecture endowed this reasoning mechanism. Experiments show that our model achieves the state-of-the-art per- formance across 8 benchmarks from 3 categories, and a limited number of training steps with the data swiftly gains a competitive performance. The code and data are publicly available at this url. 1. Introduction Benefiting from the advantage of Large Language Models (LLMs) in broad world knowledge, large Vision Language Models (VLMs) (Alayrac et al., 2022; Wang et al., 2023b) that are further trained to understand vision have demon- strated viabilities on broad scenarios, such as visual question answering (Liu et al., 2023b), visual grounding (Peng et al., 2023), optical character recognition (Zhang et al., 2023b). 1Tsinghua University2Zhipu AI‡Done as intern at Zhipu AI. Correspondence to: Bin Xu <xubin@tsinghua.edu.cn >, Jie Tang <jietang@tsinghua.edu.cn >. CogCOM VLM What is written on the pillar in front of the man in black top?Grounding(the man in black top) Grounding(pillar near the man at )CropZoomIn( , 4 times)Focus on to answer the questionFocus on to answer the questionThe letters written on the pillar are QUICK DEPOSIT.NO SMOKING Q:A: <latexit sha1_base64="k/+edjw63BcBkak5pVpf4fe8LfI=">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</latexit>b1 <latexit 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sha1_base64="Dmpt8GEE6+k1qUxrNT+OzN28VIU=">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</latexit>I0Figure 1. In comparison with existing vision-language models, CogCoM performs the multiple steps of evidential reasoning with chain of manipulations (CoM) to achieve the final answer. The research employing VLMs as foundation models (Bai et al., 2023; Sun et al., 2023b; Wang et al., 2023b) usually involves two main stages of training, where the first stage cultivates intrinsic visual understanding through exposure to massive image-caption pairs, and the second stage endows the models with problem-solving capabilities through an instruction tuning. Some other studies (Dai et al., 2023; Chen et al., 2023b; Zhang et al., 2023b) directly perform the second stage for the applicable scenes. However, existing tuning methods train models to respond to instructions with conclusive linguistic answers upon vi- sual inputs, which leads models to ignore the essential visual reasoning and further results in failures in meticulous vi- sual problems, unfaithful responses, and even hallucinations. For example in Figure 1, we test the top performing model CogVLM (Wang et al., 2023b) about the details in the image (i.e., texts written on pillar ), and it directly gives an incor- rect answer ( i.e., NO SMOKING ), most likely from bias to visual or linguistic priors ( i.e., typical scenes with pillar in office ). The absence of this evidential reasoning with visual evidence leads to a rash response (Hwang et al., 2023). Humans solve the meticulous visual problems by marking or processing the given images for convenience and rigor, 1arXiv:2402.04236v1 [cs.CV] 6 Feb 2024
2301.12652.pdf
REPLUG: Retrieval-Augmented Black-Box Language Models Weijia Shi,1 *Sewon Min,1Michihiro Yasunaga,2Minjoon Seo,3Rich James,4Mike Lewis,4 Luke Zettlemoyer1 4Wen-tau Yih4 Abstract We introduce REPLUG, a retrieval-augmented lan- guage modeling framework that treats the lan- guage model (LM) as a black box and augments it with a tuneable retrieval model. Unlike prior retrieval-augmented LMs that train language mod- els with special cross attention mechanisms to en- code the retrieved text, REPLUG simply prepends retrieved documents to the input for the frozen black-box LM. This simple design can be eas- ily applied to any existing retrieval and language models. Furthermore, we show that the LM can be used to supervise the retrieval model, which can then find documents that help the LM make better predictions. Our experiments demonstrate thatREPLUG with the tuned retriever significantly improves the performance of GPT-3 (175B) on language modeling by 6.3%, as well as the perfor- mance of Codex on five-shot MMLU by 5.1%. 1. Introduction Large language models (LLMs) such as GPT-3 (Brown et al., 2020a) and Codex (Chen et al., 2021a), have demonstrated impressive performance on a wide range of language tasks. These models are typically trained on very large datasets and store a substantial amount of world or domain knowledge implicitly in their parameters. However, they are also prone to hallucination and cannot represent the full long tail of knowledge from the training corpus. Retrieval-augmented language models (Khandelwal et al., 2020; Borgeaud et al., 2022; Izacard et al., 2022b; Yasunaga et al., 2022), in con- trast, can retrieve knowledge from an external datastore when needed, potentially reducing hallucination and increas- ing coverage. Previous approaches of retrieval-augmented language models require access to the internal LM repre- sentations (e.g., to train the model (Borgeaud et al., 2022; 1University of Washington2Stanford University3KAIST4Meta AI. *Work done while the first author was interning at Meta AI. Correspondence to: Weijia Shi <swj0419@uw.edu>. Figure 1. Different from previous retrieval-augmented ap- proaches (Borgeaud et al., 2022) that enhance a language model with retrieval by updating the LM’s parameters, REPLUG treats the language model as a black box and augments it with a frozen or tunable retriever. This black-box assumption makes REPLUG applicable to large LMs (i.e., >100B parameters), which are often served via APIs. Izacard et al., 2022b) or to index the datastore (Khandelwal et al., 2020)), and are thus difficult to be applied to very large LMs. In addition, many best-in-class LLMs can only be accessed through APIs. Internal representations of such models are not exposed and fine-tuning is not supported. In this work, we introduce REPLUG (Retrieve and Plug ), a new retrieval-augmented LM framework where the lan- guage model is viewed as a black box and the retrieval component is added as a tuneable plug-and-play module. Given an input context, REPLUG first retrieves relevant documents from an external corpus using an off-the-shelf retrieval model. The retrieved documents are prepended to the input context and fed into the black-box LM to make the final prediction. Because the LM context length limits the number of documents that can be prepended, we also introduce a new ensemble scheme that encodes the retrieved documents in parallel with the same black-box LM, allow- ing us to easily trade compute for accuracy. As shown inarXiv:2301.12652v2 [cs.CL] 1 Feb 2023
2311.05020.pdf
First Tragedy, then Parse: History Repeats Itself in the New Era of Large Language Models Naomi Saphra Kempner Institute at Harvard University nsaphra@fas.harvard.eduEve Fleisig University of California - Berkeley efleisig@berkeley.edu Kyunghyun Cho New York University & Genentech kyunghyun.cho@nyu.eduAdam Lopez University of Edinburgh alopez@inf.ed.ac.uk Abstract Many NLP researchers are experiencing an ex- istential crisis triggered by the astonishing suc- cess of ChatGPT and other systems based on large language models (LLMs). After such a disruptive change to our understanding of the field, what is left to do? Taking a historical lens, we look for guidance from the first era of LLMs, which began in 2005 with large n-gram models for machine translation. We identify durable lessons from the first era, and more importantly, we identify evergreen problems where NLP researchers can continue to make meaningful contributions in areas where LLMs are ascendant. Among these lessons, we dis- cuss the primacy of hardware advancement in shaping the availability and importance of scale, as well as the urgent challenge of quality eval- uation, both automated and human. We argue that disparities in scale are transient and that researchers can work to reduce them; that data, rather than hardware, is still a bottleneck for many meaningful applications; that meaning- ful evaluation informed by actual use is still an open problem; and that there is still room for speculative approaches. 1 Introduction Picture this scene: A renowned NLP researcher at a hot seven-year-old tech startup steps onstage to give a keynote address. The speaker describes an ambitious new system to the packed room, build- ing up to the results slide: a bar chart in which the x-axis shows the number of training words, and the y-axis shows system accuracy. As each data point is revealed, performance rises relentlessly, culmi- nating in a system trained on well over a trillion words using over a thousand processor cores. It smashes the state of the art by a margin previously thought impossible. Attendees are visibly shaken as they realize, over the course of a minute, that years of research have just been rendered utterly inconsequential. Estab- Figure 1: Results slide (reproduced from Och (2005)) of Franz Och’s keynote talk at the 2005 ACL Workshop on Building and Using Parallel Texts, a predecessor to the Conference on Machine Translation. lished academics panic, anticipating the whole- sale rejection of already-submitted grant applica- tions. PhD students despair, contemplating the irrelevance of their unfinished dissertations. Many ponder an exit to industry or a change of fields. They will speak of little else this week. Does this scene sound like one that might have happened in the past year? In fact, it happened 18 years ago, in 2005, launching the first era of Large Language Models (LLMs): the Statistical Machine Translation (SMT) era .1The speaker, Franz Och, had co-invented key methods in statisti- cal machine translation (Och and Ney, 2003; Koehn et al., 2003; Och, 2003), but had not published new work since joining Google in 2004, instead reveal- ing it in an invited talk prior to the launch of Google Translate.2The provocative results slide from that talk (Figure 1) shows how Google improved its SMT system simply by training a phrase-based lan- guage model on more and more data (Brants et al., 1The description is based on the vivid recollections of one of the authors, who was present. 2https://ai.googleblog.com/2006/04/ statistical-machine-translation-live.htmlarXiv:2311.05020v1 [cs.CL] 8 Nov 2023
Peebles-Scalable-Diffusion-Models-with-Transformers-ICCV-2023-paper.pdf
Scalable Diffusion Models with Transformers William Peebles* UC BerkeleySaining Xie New York University Figure 1: Diffusion models with transformer backbones achieve state-of-the-art image quality. We show selected sam- ples from two of our class-conditional DiT-XL/2 models trained on ImageNet at 512 ⇥512 and 256 ⇥256 resolution. Abstract We explore a new class of diffusion models based on the transformer architecture. We train latent diffusion models of images, replacing the commonly-used U-Net backbone with a transformer that operates on latent patches. We an- alyze the scalability of our Diffusion Transformers (DiTs) through the lens of forward pass complexity as measured by Gflops. We find that DiTs with higher Gflops—through in- creased transformer depth/width or increased number of in- put tokens—consistently have lower FID. In addition to pos- sessing good scalability properties, our largest DiT-XL/2 models outperform all prior diffusion models on the class- conditional ImageNet 512 ⇥512 and 256 ⇥256 benchmarks, achieving a state-of-the-art FID of 2.27 on the latter.1. Introduction Machine learning is experiencing a renaissance pow- ered by transformers. Over the past five years, neural architectures for natural language processing [ 42,8], vi- sion [ 10] and several other domains have been subsumed by transformers [ 60]. Many classes of image-level gener- ative models remain holdouts to the trend, though—while transformers see widespread use in autoregressive mod- els [43,3,6,47], they have seen less adoption in other gen- erative modeling frameworks. For example, diffusion mod- els have been at the forefront of recent advances in image generation [ 9,46]; yet, they all adopt a convolutional U-Net architecture as the de-facto choice of backbone. *Work done during an internship at Meta AI, FAIR Team. Code and project page available here. This ICCV paper is the Open Access version, provided by the Computer Vision Foundation. Except for this watermark, it is identical to the accepted version; the final published version of the proceedings is available on IEEE Xplore. 4195
hyvarinen05a.pdf
Journal ofMachineLearning Researc h6(2005) 695{709 Submitted 11/04; Revised 3/05; Published 4/05 Estimation ofNon-Normalized Statistical Models byScore Matching AapoHyvarinen aapo.hyv arinen@helsinki.fi Helsinki Institute forInformation Technolo gy(BRU) Department ofComputer Scienc e FIN-00014 University ofHelsinki, Finland Editor: PeterDayan Abstract Oneoften wantstoestimate statistical modelswhere theprobabilit ydensit yfunction is knownonlyuptoamultiplicativ enormalization constan t.Typically ,onethenhastoresort toMarkovChain MonteCarlo metho ds,orapproximations ofthenormalization constan t. Here, weproposethatsuchmodelscanbeestimated byminimizing theexpected squared distance betweenthegradien tofthelog-densit ygivenbythemodelandthegradien tof thelog-densit yoftheobserv eddata. While theestimation ofthegradien toflog-densit y function is,inprinciple, averydicult non-parametric problem, weproveasurprising result thatgivesasimple formulaforthisobjectivefunction. Thedensit yfunction ofthe observ eddatadoesnotappearinthisformula,whichsimpli es toasample average ofa sumofsomederivativesofthelog-densit ygivenbythemodel.Thevalidityofthemetho d isdemonstrated onmultivariate Gaussian andindependen tcomponentanalysis models, andbyestimating anovercomplete ltersetfornatural image data. Keywords: statistical estimation, non-normalized densities, pseudo-lik elihood,Markov chainMonteCarlo, contrastiv edivergence 1.Introduction Inmanycases, probabilistic modelsinmachinelearning, statistics, orsignal processing are givenintheformofnon-normalized probabilit ydensities. That is,themodelcontainsan unkno wnnormalization constan twhose computation istoodicult forpractical purposes. Assume weobserv earandom vectorx2Rnwhichhasaprobabilit ydensit yfunction (pdf)denoted bypx(:).Wehaveaparametrized densit ymodelp(:;),whereisanm- dimensional vector ofparameters. Wewanttoestimate theparameterfromx,i.e.we wanttoapproximatepx(:)byp(:;^)fortheestimated parameter value^.(Weshallhere consider thecaseofcontinuous-v alued variables only.) Theproblem weconsider hereisthatweonlyareabletocompute thepdfgivenbythe modeluptoamultiplicativ econstan tZ(): p(;)=1 Z()q(;): Thatis,wedoknowthefunctional formofqasananalytical expression (oranyformthat canbeeasily computed), butwedonotknowhowtoeasily computeZwhichisgivenby c 2005AapoHyvarinen.
2403.09611.pdf
MM1: Methods, Analysis & Insights from Multimodal LLM Pre-training Brandon McKinzie◦, Zhe Gan◦, Jean-Philippe Fauconnier⋆, Sam Dodge⋆, Bowen Zhang⋆, Philipp Dufter⋆, Dhruti Shah⋆, Xianzhi Du⋆, Futang Peng, Floris Weers, Anton Belyi, Haotian Zhang, Karanjeet Singh, Doug Kang, Hongyu Hè, Max Schwarzer, Tom Gunter, Xiang Kong, Aonan Zhang, Jianyu Wang, Chong Wang, Nan Du, Tao Lei, Sam Wiseman, Mark Lee, Zirui Wang, Ruoming Pang, Peter Grasch⋆, Alexander Toshev†, and Yinfei Yang† Apple bmckinzie@apple.com ,zhe.gan@apple.com ◦First authors;⋆Core authors;†Senior authors Abstract. In this work, we discuss building performant Multimodal Large Language Models (MLLMs). In particular, we study the impor- tance of various architecture components and data choices. Through careful and comprehensive ablations of the image encoder, the vision language connector, and various pre-training data choices, we identi- fied several crucial design lessons. For example, we demonstrate that for large-scale multimodal pre-training using a careful mix of image-caption, interleaved image-text, and text-only data is crucial for achieving state- of-the-art (SOTA) few-shot results across multiple benchmarks, com- pared to other published pre-training results. Further, we show that the image encoder together with image resolution and the image token count has substantial impact, while the vision-language connector design is of comparatively negligible importance. By scaling up the presented recipe, we build MM1, a family of multimodal models up to 30B parameters, consisting of both dense models and mixture-of-experts (MoE) variants, that are SOTA in pre-training metrics and achieve competitive perfor- mance after supervised fine-tuning on a range of established multimodal benchmarks. Thanks to large-scale pre-training, MM1 enjoys appealing properties such as enhanced in-context learning, and multi-image rea- soning, enabling few-shot chain-of-thought prompting. 1 Introduction In recent years, the research community has achieved impressive progress in language modeling and image understanding. Thanks to the availability of large- scaleimage-textdataandcomputeatscale,wehaveseentheemergenceofhighly performant Large Language Models (LLMs) [9,10,19,21,26,92,93,103,108,110, 117,130] and Vision Foundation Models [40,88,91] that have become the de- factostandard for the majority of language and image understanding problems.arXiv:2403.09611v1 [cs.CV] 14 Mar 2024
1905.04226.pdf
Language Modeling with Deep Transformers Kazuki Irie1, Albert Zeyer1,2, Ralf Schl ¨uter1, Hermann Ney1,2 1Human Language Technology and Pattern Recognition Group, Computer Science Department RWTH Aachen University, 52074 Aachen, Germany 2AppTek GmbH, 52062 Aachen, Germany {irie, zeyer, schlueter, ney }@cs.rwth-aachen.de Abstract We explore deep autoregressive Transformer models in language modeling for speech recognition. We focus on two aspects. First, we revisit Transformer model configurations specifically for language modeling. We show that well configured Trans- former models outperform our baseline models based on the shallow stack of LSTM recurrent neural network layers. We carry out experiments on the open-source LibriSpeech 960hr task, for both 200K vocabulary word-level and 10K byte-pair encoding subword-level language modeling. We apply our word- level models to conventional hybrid speech recognition by lat- tice rescoring, and the subword-level models to attention based encoder-decoder models by shallow fusion. Second, we show that deep Transformer language models do not require positional encoding. The positional encoding is an essential augmentation for the self-attention mechanism which is invariant to sequence ordering. However, in autoregressive setup, as is the case for lan- guage modeling, the amount of information increases along the position dimension, which is a positional signal by its own. The analysis of attention weights shows that deep autoregressive self- attention models can automatically make use of such positional information. We find that removing the positional encoding even slightly improves the performance of these models. Index Terms : language modeling, self-attention, Transformer, speech recognition 1. Introduction Transformer encoder-decoder models [1] have become popular in natural language processing. The Transformer architecture allows to successfully train a deep stack of self-attention lay- ers [2 –4] via residual connections [5] and layer normalization [6]. The positional encodings [1, 7], typically based on sinusoidal functions, are used to provide the self-attention with the sequence order information. Across various applications, systematic im- provements have been reported over the standard, multi-layer long short-term memory (LSTM) [8] recurrent neural network based models. While originally designed as an encoder-decoder architecture in machine translation, the encoder (e.g., [9]) and thedecoder (e.g., [10]) components are also separately used in corresponding problems depending on whether the problem disposes the whole sequence for prediction or not. A number of recent works have also shown impressive per- formance in language modeling using the Transformer decoder component [10 –15]. The earliest example can be found in [10] where such models are investigated for text generation. Re- cent works on training larger and deeper models [12, 14, 15] have shown further potential of the Transformer in language modeling. On the other hand, an obvious limitation of the Trans- formers is that their memory requirement linearly increases in terms of number of tokens in the sequence, which requires to work with a limited context window (basically a n-gram model where the typical number for nis 512) for tasks dealing with long sequences such as character-level language modeling [12]. Dai et al. [11] has introduced a segment-level recurrence andrelative positional encoding in the Transformer language model to be able to potentially handle unlimited context. In this work, we investigate deep autoregressive Transform- ers for language modeling in speech recognition. To be specific, we focus on two aspects. First, we revisit the parameter configu- rations of Transformers, originally engineered for the sequence- to-sequence problem [1], specifically for language modeling. We conduct experiments on the LibriSpeech automatic speech recog- nition (ASR) task [16] for both word-level conventional speech recognition and byte-pair encoding (BPE) [17] level end-to-end speech recognition [18, 19]. We apply our word-level models to hybrid speech recognition by lattice rescoring [20], and the BPE- level models to end-to-end models by shallow fusion [21, 22]. We show that well configured Transformer language models out- perform models based on the simple stack of LSTM RNN layers in terms of both perplexity and word error rate (WER). Second, we experimentally show that the positional encod- ing is not needed for multi-layer autoregressive self-attention models. The visualization of the attention weights shows that when the sinusoidal positional encoding is provided with the input, the first layer of the Transformers learns to extract n- gram features (therefore making use of positional information). However, in the autoregressive problem where a new token is provided to the model at each time step, the amount of infor- mation the model has access to strictly increases from left to right at the lowest level of the network, which should provide some positional information by its own. We observe that deep Transformer language models without positional encoding au- tomatically make use of such information, and even give slight improvements over models with positional encodings. 2. Related Work The first part of our work follows the spirits of Al-Rfou et al.’s work [12] and Radford et al.’s work [14,15] in investigating larger and deeper Transformers for language modeling. We show that deep Transformer language models can be successfully applied to speech recognition and give good performance. The second part of this work concerns the positional encoding, which is a crucial component in the original Transformer. A number of pre- vious work investigated positional encoding variants to improve self-attention (e.g., [11, 23 –25]). Previous works in Transformer language models systematically use positional encoding, either jointly learned one or the sinusoidal one (both cases are reported to give similar performance in [12]). We show that the deep autoregressive self-attention models do not require any explicit model for encoding positions to give the best performance. 3. Autoregressive Self-Attention The language model we consider is based on the decoder com- ponent of the Transformer architecture [1]. Similar to previous work [10 –15], we define layer as a stack of two components: self-attention andfeed-forward1modules. 1Typically called position-wise feed-forward module [1]. Here we omit position-wise as it is obvious for autoregressive models.arXiv:1905.04226v2 [cs.CL] 11 Jul 2019
10.1038.s41467-023-37023-9.pdf
Article https://doi.org/10.1038/s41467-023-37023-9 Observation of electron orbital signatures of single atoms within metal-phthalocyaninesusing atomic force microscopy Pengcheng Chen1,9, Dingxin Fan1,2,9, Annabella Selloni3,E m i l yA .C a r t e r4,5, Craig B. Arnold1,4, Yunlong Zhang6,A d a mS .G r o s s6, James R. Chelikowsky2,7,8&N a nY a o1 Resolving the electronic structure of a single atom within a molecule is of fundamental importance for understanding and predicting chemical andphysical properties of functional molecu les such as molecular catalysts. How- ever, the observation of the orbital signature of an individual atom is challen-ging. We report here the direct identi fication of two adjacent transition-metal atoms, Fe and Co, within phthalocyanine molecules using high-resolutionnoncontact atomic force microscopy (HR-AFM). HR-AFM imaging reveals thatthe Co atom is brighter and presents four distinct lobes on the horizontal planewhereas the Fe atom displays a “square ”morphology. Pico-force spectroscopy measurements show a larger repulsion force of about 5 pN on the tip exertedby Co in comparison to Fe. Our combined ex perimental and theoretical results demonstrate that both the distinguishable features in AFM images and thevariation in the measured forces arise from Co ’s higher electron orbital occu- pation above the molecular plane. The ability to directly observe orbital sig-natures using HR-AFM should provide a pr omising approach to characterizing the electronic structure of an individual atom in a molecular species and tounderstand mechanisms of certain chemical reactions. Real-space experimental observation of localized electron orbital sig- natures for individual atoms within complex systems can elucidate how atoms interact with each other and provide critical information onthe dissociation and formation of chemical bonds needed for identi-fying reaction pathways. However, the direct measurement of theelectronic structure of a single atom or a chemical bond is challenging.Several experimental methods have enabled probing of molecularorbital distributions under certain conditions, including angle-resolvedphotoemission spectroscopy 1,2, high harmonic interferometry3,a n dphotoionization microscopy4. In real space, orbital-related information can be obtained with scanning tunneling microscopy (STM)5–10,w h i c h images the spatially resolved local density of states near theFermi level 11. In addition, HR-AFM with molecularly functionalized tips has been used for quantitative structural measurements on organicmolecules with spectacular atomic resolution 12,13.B o n do r d e r14,15and heteroatom16,17discrimination, and even real-space imaging of indivi- dual atoms18,19and intermolecular bonds have been reported20,21.T h e s e experimental advances have been accompanied by the innovation ofReceived: 3 October 2022 Accepted: 20 February 2023 Check for updates 1Princeton Materials Institute, Princeton University, Princeton, NJ 08540-8211, USA.2McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX 78712-1589, USA.3Department of Chemistry, Princeton University, Princeton, NJ 08544-0001, USA.4Department of Mechanical and Aerospace Engineering and the Andlinger Center for Energy and the Environment, Princeton University, Princeton, NJ 08544-5263, USA.5Princeton Plasma Physics Laboratory, Princeton, NJ 08540-6655, USA.6ExxonMobil Technology and Engineering Company, Annandale, NJ 08801-3096, USA.7Department of Physics, University of Texas at Austin, Austin, TX 78712-1192, USA.8Center for Computational Materials, Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, TX 78712-1229, USA.9These authors contributed equally: Pengcheng Chen, Dingxin Fan. e-mail: jrc@utexas.edu ;nyao@princeton.edu Nature Communications | (2023) 14:1460 11234567890():,; 1234567890():,;
Text2Graphics.pdf
Text to Graphics by Program Synthesis with Error Correction on Precise, Procedural, and Simulation Tasks Arvind Raghavan Columbia University ar4284@columbia.eduZad Chin Harvard University zadchin@college.harvard.eduAlexander E. Siemenn MIT asiemenn@mit.edu Vitali Petsiuk Boston University vpetsiuk@bu.eduSaisamrit Surbehera Columbia University ss6365@columbia.eduYann Hicke Cornell University ylh8@cornell.eduEd Chien Boston University edchien@bu.edu Ori Kerret Ven Commerce ori@ven.comTonio Buonassisi MIT buonassi@mit.eduKate Saenko Boston University saenko@bu.eduArmando Solar-Lezama MIT armando@csail.mit.edu Iddo Drori MIT, Columbia University, Boston University idrori@mit.edu,idrori@cs.columbia.edu Abstract Current text-to-image methods fail on visual tasks that require precision or a procedural specification. DALL- E 2 and StableDiffusion fit well into frameworks such as Photoshop; however, they cannot accomplish precise de- sign, engineering, or physical simulation tasks. We cor- rectly perform such tasks by turning them into program- ming tasks, automatically generating code with the latest graphics libraries, and then running code to render images. Code generation models such as Codex often generate er- rors on complex programs, so we perform local error cor- rection. Rather than subjectively evaluating results on a set of prompts, we generate a new multi-task benchmark of challenge tasks. We demonstrate the applicability of our approach for precise and procedural rendering and physi- cal simulations. 1. Introduction Text-to-image methods such as DALL-E 2 [16] and Sta- bleDiffusion [18] are remarkably effective at producing cre- ative and novel images that reflect a user prompt. The re- sults have captured the popular imagination, and artists are already using these systems as tools in their creative pro- cess [17]. However, these methods have various failure modes that disrupt this process. For example, they oftenfail to produce precise results and respond appropriately to specified numeracy, positions, spellings, etc. They also do not allow for simple compositional changes to the image, such as modifying the color or styling of a particular ob- ject without manual marking or outlining. Finally, they may produce images that defy conventional physics. We address these particular issues by reframing the prob- lem as one of graphics code generation. When a scene is specified at the code level, precision in numerics and posi- tioning is required, objects are instantiated separately and specified, and realistic physics models are generated. Our particular model uses Codex [3] to generate Python code for rendering objects in Blender [6] and further leverages aprogram synthesis approach, allowing for automatic error correction and user-guided edits to the output image. Figure 1 shows a schematic of this. To demonstrate the efficacy of our method, we show that it outperforms DALL-E 2 and StableDiffusion on tasks from a recent benchmark designed to test the ability of these systems to cope with challenging prompts. In summary, our contributions are listed below: • We reframe the problem of image generation as one of graphics code generation, allowing for unparalleled precision and compositional control over the image output. • We leverage program synthesis tools, allowing for au- tomatic error correction and user-guided modification
2307.00494.pdf
Optimizing protein fitness using Gibbs sampling with Graph-based Smoothing Andrew Kirjner∗ Massachusetts Institute of Technology kirjner@mit.eduJason Yim∗ Massachusetts Institute of Technology jyim@mit.edu Raman Samusevich IOCB, Czech Academy of Sciences, CIIRC, Czech Technical University in Prague raman.samusevich@uochb.cas.czTommi Jaakkola† Massachusetts Institute of Technology tommi@csail.mit.edu Regina Barzilay† Massachusetts Institute of Technology regina@csail.mit.eduIla Fiete† Massachusetts Institute of Technology fiete@mit.edu Abstract The ability to design novel proteins with higher fitness on a given task would be revolutionary for many fields of medicine. However, brute-force search through the combinatorially large space of sequences is infeasible. Prior methods constrain search to a small mutational radius from a reference sequence, but such heuristics drastically limit the design space. Our work seeks to remove the restriction on mu- tational distance while enabling efficient exploration. We propose Gibbs sampling with Graph-based Smoothing (GGS) which iteratively applies Gibbs with gradients to propose advantageous mutations using graph-based smoothing to remove noisy gradients that lead to false positives. Our method is state-of-the-art in discovering high-fitness proteins with up to 8 mutations from the training set. We study the GFP and AA V design problems, ablations, and baselines to elucidate the results. Code: https://github.com/kirjner/GGS 1 Introduction In protein design, fitness is loosely defined as performance on a desired property or function. Ex- amples of fitness include catalytic activity for enzymes [ 1,21] and fluorescence for biomarkers [ 29]. Protein engineering seeks to design proteins with high fitness by altering the underlying sequences of amino acids. However, the number of possible proteins increases exponentially with sequence length, rendering it infeasible to perform brute-force search to engineer novel functions which often requires many mutations (i.e. at least 3 [ 12]). Directed evolution [ 3] has been successful in improving protein fitness, but it requires substantial labor and time to gradually explore many mutations. We aim to find shortcuts to generate high-fitness proteins that are many mutations away from what is known but face several challenges. Proteins are notorious for highly non-smooth fitness landscapes:3 fitness can change dramatically with just a single mutation, and most protein sequences have zero ∗Contributed equally to this work. Authors agreed ordering can be changed for their respective interests. †Advised equally to this work. 3Landscape refers to the mapping from sequence to fitness. Preprint. Under review.arXiv:2307.00494v1 [q-bio.BM] 2 Jul 2023
2302.05442.pdf
Scaling Vision Transformers to 22 Billion Parameters Mostafa Dehghani∗Josip Djolonga∗Basil Mustafa∗Piotr Padlewski∗Jonathan Heek∗ Justin Gilmer Andreas Steiner Mathilde Caron Robert Geirhos Ibrahim Alabdulmohsin Rodolphe Jenatton Lucas Beyer Michael Tschannen Anurag Arnab Xiao Wang Carlos Riquelme Matthias Minderer Joan Puigcerver Utku Evci Manoj Kumar Sjoerd van Steenkiste Gamaleldin F. Elsayed Aravindh Mahendran Fisher Yu Avital Oliver Fantine Huot Jasmijn Bastings Mark Patrick Collier Alexey A. Gritsenko Vighnesh Birodkar Cristina Vasconcelos Yi Tay Thomas Mensink Alexander Kolesnikov Filip Pavetić Dustin Tran Thomas Kipf Mario Lučić Xiaohua Zhai Daniel Keysers Jeremiah Harmsen Neil Houlsby∗ Google Research Abstract The scalingof Transformers has drivenbreakthrough capabilities forlanguagemodels. At present,the largestlargelanguagemodels(LLMs)containupwardsof100Bparameters. VisionTransformers(ViT)have introducedthesamearchitecturetoimageandvideomodelling,butthesehavenotyetbeensuccessfully scaled to nearly the same degree; the largest dense ViT contains 4B parameters (Chen et al., 2022). We present a recipe for highly efficient and stable training of a 22B-parameter ViT ( ViT-22B) and perform a widevarietyofexperimentsontheresultingmodel. Whenevaluatedondownstreamtasks(oftenwitha lightweight linear model on frozen features), ViT-22Bdemonstrates increasing performance with scale. We further observe other interesting benefits of scale, including an improved tradeoff between fairness and performance, state-of-the-art alignment to human visual perception in terms of shape/texture bias, and improvedrobustness. ViT-22Bdemonstratesthepotentialfor“LLM-like”scalinginvision,andprovides key steps towards getting there. 1 Introduction Similar to natural language processing, transfer of pre-trained vision backbones has improved performance on a wide variety of vision tasks (Pan and Yang, 2010; Zhai et al., 2019; Kolesnikov et al., 2020). Larger datasets, scalable architectures, and new training methods (Mahajan et al., 2018; Dosovitskiy et al., 2021; Radford et al., 2021; Zhai et al., 2022a) have accelerated this growth. Despite this, vision models have trailed far behind language models, which have demonstrated emergent capabilities at massive scales (Chowdhery et al., 2022; Wei et al., 2022). Specifically, the largest dense vision model to date is a mere 4B parameter ViT(Chenetal.,2022),whileamodestlyparameterizedmodelforanentry-levelcompetitivelanguagemodel typically contains over 10B parameters (Raffel et al., 2019; Tay et al., 2022; Chung et al., 2022), and the largest dense language model has 540B parameters (Chowdhery et al., 2022). Sparse models demonstrate the same trend, wherelanguage modelsgo beyond atrillion parameters(Fedus etal., 2021)but thelargestreported sparse vision models are only 15B (Riquelme et al., 2021). Thispaperpresents ViT-22B,thelargestdenseViTmodeltodate. Enrouteto22Bparameters,weuncover pathologicaltraininginstabilitieswhichpreventscalingthedefaultrecipe,anddemonstratearchitectural changeswhichmakeitpossible. Further,wecarefullyengineerthemodeltoenablemodel-paralleltrainingat unprecedentedefficiency. ViT-22B’squalityisassessedviaacomprehensiveevaluationsuiteoftasks,ranging from (few-shot) classification to dense output tasks, where it reaches or advances the current state-of-the-art. For example, even when used as a frozen visual feature extractor, ViT-22Bachieves an accuracy of 89.5% on ∗Core contributors. Correspondence: dehghani@google.com 1arXiv:2302.05442v1 [cs.CV] 10 Feb 2023
2103.00020.pdf
Learning Transferable Visual Models From Natural Language Supervision Alec Radford* 1Jong Wook Kim* 1Chris Hallacy1Aditya Ramesh1Gabriel Goh1Sandhini Agarwal1 Girish Sastry1Amanda Askell1Pamela Mishkin1Jack Clark1Gretchen Krueger1Ilya Sutskever1 Abstract State-of-the-art computer vision systems are trained to predict a fixed set of predetermined object categories. This restricted form of super- vision limits their generality and usability since additional labeled data is needed to specify any other visual concept. Learning directly from raw text about images is a promising alternative which leverages a much broader source of supervision. We demonstrate that the simple pre-training task of predicting which caption goes with which im- age is an efficient and scalable way to learn SOTA image representations from scratch on a dataset of 400 million (image, text) pairs collected from the internet. After pre-training, natural language is used to reference learned visual concepts (or describe new ones) enabling zero-shot transfer of the model to downstream tasks. We study the performance of this approach by benchmark- ing on over 30 different existing computer vi- sion datasets, spanning tasks such as OCR, ac- tion recognition in videos, geo-localization, and many types of fine-grained object classification. The model transfers non-trivially to most tasks and is often competitive with a fully supervised baseline without the need for any dataset spe- cific training. For instance, we match the ac- curacy of the original ResNet-50 on ImageNet zero-shot without needing to use any of the 1.28 million training examples it was trained on. We release our code and pre-trained model weights at https://github.com/OpenAI/CLIP . 1. Introduction and Motivating Work Pre-training methods which learn directly from raw text have revolutionized NLP over the last few years (Dai & Le, 2015; Peters et al., 2018; Howard & Ruder, 2018; Rad- ford et al., 2018; Devlin et al., 2018; Raffel et al., 2019). *Equal contribution1OpenAI, San Francisco, CA 94110, USA. Correspondence to: <{alec, jongwook}@openai.com >.Task-agnostic objectives such as autoregressive and masked language modeling have scaled across many orders of mag- nitude in compute, model capacity, and data, steadily im- proving capabilities. The development of “text-to-text” as a standardized input-output interface (McCann et al., 2018; Radford et al., 2019; Raffel et al., 2019) has enabled task- agnostic architectures to zero-shot transfer to downstream datasets removing the need for specialized output heads or dataset specific customization. Flagship systems like GPT-3 (Brown et al., 2020) are now competitive across many tasks with bespoke models while requiring little to no dataset specific training data. These results suggest that the aggregate supervision acces- sible to modern pre-training methods within web-scale col- lections of text surpasses that of high-quality crowd-labeled NLP datasets. However, in other fields such as computer vision it is still standard practice to pre-train models on crowd-labeled datasets such as ImageNet (Deng et al., 2009). Could scalable pre-training methods which learn directly from web text result in a similar breakthrough in computer vision? Prior work is encouraging. Over 20 years ago Mori et al. (1999) explored improving content based image retrieval by training a model to pre- dict the nouns and adjectives in text documents paired with images. Quattoni et al. (2007) demonstrated it was possi- ble to learn more data efficient image representations via manifold learning in the weight space of classifiers trained to predict words in captions associated with images. Sri- vastava & Salakhutdinov (2012) explored deep represen- tation learning by training multimodal Deep Boltzmann Machines on top of low-level image and text tag features. Joulin et al. (2016) modernized this line of work and demon- strated that CNNs trained to predict words in image cap- tions learn useful image representations. They converted the title, description, and hashtag metadata of images in the YFCC100M dataset (Thomee et al., 2016) into a bag-of- words multi-label classification task and showed that pre- training AlexNet (Krizhevsky et al., 2012) to predict these labels learned representations which preformed similarly to ImageNet-based pre-training on transfer tasks. Li et al. (2017) then extended this approach to predicting phrase n- grams in addition to individual words and demonstrated the ability of their system to zero-shot transfer to other imagearXiv:2103.00020v1 [cs.CV] 26 Feb 2021
2304.10464.pdf
Learning to Program with Natural Language Yiduo Guo1, Yaobo Liang2, Chenfei Wu2, Wenshan Wu2, Dongyan Zhao1, Duan Nan2 1Wangxuan Institute of Computer Technology, Peking University,2Microsoft Research, Asia yiduo@stu.pku.edu.cn, zhaodongyan@pku.edu.cn {yaobo.liang, chenfei.wu, wenshan.wu, nanduan}@microsoft.com Abstract Large Language Models (LLMs) have shown remarkable performance in various basic natural language tasks, which raises hopes for achieving Artificial General Intelligence. To better complete complex tasks, we need LLMs to program for the task and then follow the program to generate a specific solution for the test sample. We propose using natural language as a new programming language to describe task procedures, making them easily understandable to both humans and LLMs. The LLM is capable of directly generating natural language programs, but these programs may still contain factual errors or incomplete steps. Therefore, we further propose the Learning to Program ( LP) method to ask LLMs themselves to learn natural language programs from the training dataset of complex tasks and then use the learned program to guide inference. Our experiments on the AMPS (high school math) and Math (competition mathematics problems) datasets demonstrate the effectiveness of our approach. When testing ChatGPT on 10 tasks from the AMPS dataset, our LPmethod’s average performance outperformed the direct zero-shot test performance by 18.3 %. We release our code at https: //github.com/microsoft/NaturalLanguageProgram . 1 Introduction Large Language Models (LLMs), such as ChatGPT and GPT-4 [17], have recently achieved strong zero-shot/few-shot performance on various natural language tasks, such as generating passages [1], generating code [14], and solving grade school math problems [19]. LLMs can further learn new basic abilities by connecting them with millions of APIs like TaskMatrix.AI [13, 26] or new tools like ToolFormer [21]. However, LLMs still struggle to complete complex tasks, such as writing a long novel [27], coding for a large project [18], and solving complex math problems [5]. This indicates that knowing every basic capability is insufficient to complete complex tasks - we also require a procedure for how to combine them. Like programmers who use programming languages to teach computers how to complete complex tasks, we propose leveraging natural language as the new programming language to teach LLMs how to complete complex tasks. To better control the inference process for complex tasks, we propose to make the inference process into two steps explicitly: In the first step, we find a natural language program pfor the test sample. In the second step, we use the test sample, prompt, and natural language program pas the input to LLMs to generate the specific solution. Natural Language Programs can guide LLMs by first analyzing all possible cases and then decomposing the complex task into sub-tasks, sequentially employing functions to complete the task. These programs provide general solutions that explain the generic steps to solve the task, including which basic capability to use and the necessary background knowledge. For example, if the task is to calculate the sine value of an angle in a right triangle, given the lengths of its legs, the natural language program for this task would be as follows: First, use the Pythagorean theorem to calculate the length of the leg whose length is not given. Then, calculate the sine value of the target angle based on its definition. Natural language programs offer two key advantages: (1) generalizability, as they can guide LLMs to solve all questions similar to thearXiv:2304.10464v1 [cs.CL] 20 Apr 2023
2112.11446.pdf
2021-12-08 Scaling Language Models: Methods, Analysis & Insights from Training Gopher Jack W. Rae, Sebastian Borgeaud, Trevor Cai, Katie Millican, Jordan Hoffmann, Francis Song, John Aslanides, Sarah Henderson, Roman Ring, Susannah Young, Eliza Rutherford, Tom Hennigan, Jacob Menick, Albin Cassirer, Richard Powell, George van den Driessche, Lisa Anne Hendricks, Maribeth Rauh, Po-Sen Huang, Amelia Glaese, Johannes Welbl, Sumanth Dathathri, Saffron Huang, Jonathan Uesato, John Mellor, Irina Higgins, Antonia Creswell, Nat McAleese, Amy Wu, Erich Elsen, Siddhant Jayakumar, Elena Buchatskaya, David Budden, Esme Sutherland, Karen Simonyan, Michela Paganini, Laurent Sifre, Lena Martens, Xiang Lorraine Li, Adhiguna Kuncoro, Aida Nematzadeh, Elena Gribovskaya, Domenic Donato, Angeliki Lazaridou, Arthur Mensch, Jean-Baptiste Lespiau, Maria Tsimpoukelli, Nikolai Grigorev, Doug Fritz, Thibault Sottiaux, Mantas Pajarskas, Toby Pohlen, Zhitao Gong, Daniel Toyama, Cyprien de Masson d’Autume, Yujia Li, Tayfun Terzi, Vladimir Mikulik, Igor Babuschkin, Aidan Clark, Diego de Las Casas, Aurelia Guy, Chris Jones, James Bradbury, Matthew Johnson, Blake Hechtman, Laura Weidinger, Iason Gabriel, William Isaac, Ed Lockhart, Simon Osindero, Laura Rimell, Chris Dyer, Oriol Vinyals, Kareem Ayoub, Jeff Stanway, Lorrayne Bennett, Demis Hassabis, Koray Kavukcuoglu and Geoffrey Irving Language modelling provides a step towards intelligent communication systems by harnessing large repositories of written human knowledge to better predict and understand the world. In this paper, we present an analysis of Transformer-based language model performance across a wide range of model scales — from models with tens of millions of parameters up to a 280 billion parameter model called Gopher. Thesemodelsareevaluatedon152diversetasks,achievingstate-of-the-artperformanceacross the majority. Gains from scale are largest in areas such as reading comprehension, fact-checking, and theidentificationoftoxiclanguage,butlogicalandmathematicalreasoningseelessbenefit. Weprovide a holistic analysis of the training dataset and model’s behaviour, covering the intersection of model scale with bias and toxicity. Finally we discuss the application of language models to AI safety and the mitigation of downstream harms. Keywords: Natural Language Processing, Language Models, Deep Learning Contents 1 Introduction 3 2 Background 5 3 Method 5 3.1 Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 3.2 Training . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.3 Infrastructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3.4 Training Dataset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 4 Results 7 4.1 Task Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 4.2 Comparisons with State of the Art . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Corresponding authors: jack.w.rae@gmail.com, geoffreyi@deepmind.com ©2022 DeepMind. All rights reservedarXiv:2112.11446v2 [cs.CL] 21 Jan 2022
2310.06825.pdf
Mistral 7B Albert Q. Jiang, Alexandre Sablayrolles, Arthur Mensch, Chris Bamford, Devendra Singh Chaplot, Diego de las Casas, Florian Bressand, Gianna Lengyel, Guillaume Lample, Lucile Saulnier, Lélio Renard Lavaud, Marie-Anne Lachaux, Pierre Stock, Teven Le Scao, Thibaut Lavril, Thomas Wang, Timothée Lacroix, William El Sayed Abstract We introduce Mistral 7B, a 7–billion-parameter language model engineered for superior performance and efficiency. Mistral 7B outperforms the best open 13B model (Llama 2) across all evaluated benchmarks, and the best released 34B model (Llama 1) in reasoning, mathematics, and code generation. Our model leverages grouped-query attention (GQA) for faster inference, coupled with sliding window attention (SWA) to effectively handle sequences of arbitrary length with a reduced inference cost. We also provide a model fine-tuned to follow instructions, Mistral 7B – Instruct, that surpasses Llama 2 13B – chat model both on human and automated benchmarks. Our models are released under the Apache 2.0 license. Code: https://github.com/mistralai/mistral-src Webpage: https://mistral.ai/news/announcing-mistral-7b/ 1 Introduction In the rapidly evolving domain of Natural Language Processing (NLP), the race towards higher model performance often necessitates an escalation in model size. However, this scaling tends to increase computational costs and inference latency, thereby raising barriers to deployment in practical, real-world scenarios. In this context, the search for balanced models delivering both high-level performance and efficiency becomes critically essential. Our model, Mistral 7B, demonstrates that a carefully designed language model can deliver high performance while maintaining an efficient inference. Mistral 7B outperforms the previous best 13B model (Llama 2, [ 26]) across all tested benchmarks, and surpasses the best 34B model (LLaMa 34B, [ 25]) in mathematics and code generation. Furthermore, Mistral 7B approaches the coding performance of Code-Llama 7B [ 20], without sacrificing performance on non-code related benchmarks. Mistral 7B leverages grouped-query attention (GQA) [ 1], and sliding window attention (SWA) [ 6,3]. GQA significantly accelerates the inference speed, and also reduces the memory requirement during decoding, allowing for higher batch sizes hence higher throughput, a crucial factor for real-time applications. In addition, SWA is designed to handle longer sequences more effectively at a reduced computational cost, thereby alleviating a common limitation in LLMs. These attention mechanisms collectively contribute to the enhanced performance and efficiency of Mistral 7B.arXiv:2310.06825v1 [cs.CL] 10 Oct 2023
2304.06762.pdf
Shall We Pretrain Autoregressive Language Models with Retrieval? A Comprehensive Study Boxin Wang∗‡1Wei Ping∗†2Peng Xu∗2Lawrence McAfee2 Zihan Liu2Mohammad Shoeybi2Yi Dong2Oleksii Kuchaiev2 Bo Li1Chaowei Xiao2,3Anima Anandkumar2Bryan Catanzaro2 Abstract Large decoder-only language models (LMs) can be largely improved in terms of perplex- ity by retrieval ( e.g., RETRO ), but its impact on text generation quality and downstream task accuracy is unclear. Thus, it is still an open question: shall we pretrain large au- toregressive LMs with retrieval? To answer it, we perform a comprehensive study on a scalable pretrained retrieval-augmented LM (i.e., R ETRO ) compared with standard GPT and retrieval-augmented GPT incorporated at fine-tuning or inference stages. We first pro- vide the recipe to reproduce R ETRO up to 9.5B parameters while retrieving a text corpus with 330B tokens. Based on that, we have the following novel findings: i)RETRO out- performs GPT on text generation with much less degeneration (i.e., repetition), moderately higher factual accuracy, and slightly lower toxicity with a nontoxic retrieval database. ii)On the LM Evaluation Harness bench- mark, R ETRO largely outperforms GPT on knowledge-intensive tasks, but is on par with GPT on other tasks. Furthermore, we intro- duce a simple variant of the model, R ETRO ++, which largely improves open-domain QA re- sults of original R ETRO (e.g., EM score +8.6 on Natural Question) and significantly outper- forms retrieval-augmented GPT across differ- ent model sizes. Our findings highlight the promising direction of pretraining autoregres- sive LMs with retrieval as future foundation models. We release our implementation at: https://github.com/NVIDIA/Megatron -LM#retro . 1 Introduction Large language models (LMs), including masked LMs (e.g., BERT (Devlin et al., 2018)), autore- gressive LMs (e.g., GPT (Brown et al., 2020)), and encoder-decoder LMs (e.g., T5 (Raffel et al., ∗Equal contribution. ‡Work done during an internship at NVIDIA.1UIUC.2NVIDIA.3ASU. †Correspondence to: Wei Ping <wping@nvidia.com>2020), BART (Lewis et al., 2020a)), have ob- tained state-of-the-art results for various NLP tasks. Among them, the autoregressive LMs like GPT- 3 (Brown et al., 2020) and GPT-4 (OpenAI, 2023) demonstrate noticeable in-context learning abil- ity and excellent long-form text generation results. Due to its importance, the community has spent considerable efforts to scale up such autoregres- sive generative LMs with more data and param- eters and observed significant breakthroughs in a variety of real-world applications (e.g., Brown et al., 2020), including open-ended text genera- tion and various downstream tasks (e.g., ques- tion answering). The successful public exam- ples include GPT-3 (w/ 170B parameters) (Brown et al., 2020), Gopher (280B) (Rae et al., 2021), Megatron-Turing (530B) (Smith et al., 2022), and PaLM (540B) (Chowdhery et al., 2022). Although large-scale autoregressive LMs have achieved huge successes, they also suffer from sev- eral weaknesses. First, it requires a huge number of model parameters to memorize the world knowl- edge, which makes it costly for deployment. Sec- ond, it is difficult to safeguard factual accuracy, which may provide users with incorrect informa- tion (Lee et al., 2022). Third, it is expensive to update the model knowledge learned during pre- training with up-to-date facts (Meng et al., 2022), yielding outdated answers (Lewis et al., 2020b). To mitigate the problems above, one line of research proposes to improve language models with retrieval. The retrieval process can be inte- grated into LMs at: i)fine-tuning stage (Karpukhin et al., 2020; Lewis et al., 2020b; Guu et al., 2020), orii)pretraining stage (Borgeaud et al., 2022; Izacard et al., 2022). Most previous work aug- ments BERT or encoder-decoder LMs with re- trieval at fine-tuning stage, demonstrating suc- cesses for knowledge-intensive NLP tasks (Guu et al., 2020; Karpukhin et al., 2020; Lewis et al., 2020b; Khandelwal et al., 2020). However, it re-arXiv:2304.06762v1 [cs.CL] 13 Apr 2023
2404.12096.pdf
LONG EMBED : EXTENDING EMBEDDING MODELS FOR LONG CONTEXT RETRIEVAL Dawei Zhu∗ηLiang WangπNan YangπYifan SongηWenhao Wuη Furu WeiπSujian Liη ηPeking UniversityπMicrosoft Corporation https://github.com/dwzhu-pku/LongEmbed ABSTRACT Embedding models play a pivot role in modern NLP applications such as IR and RAG. While the context limit of LLMs has been pushed beyond 1 million tokens, embedding models are still confined to a narrow context window not exceeding 8k tokens, refrained from application scenarios requiring long inputs such as legal contracts. This paper explores context window extension of existing embedding models, pushing the limit to 32k without requiring additional training. First, we examine the performance of current embedding models for long context retrieval on our newly constructed LONGEMBED benchmark. LONGEMBED comprises two synthetic tasks and four carefully chosen real-world tasks, featuring documents of varying length and dispersed target information. Benchmarking results underscore huge room for improvement in these models. Based on this, comprehensive exper- iments show that training-free context window extension strategies like position interpolation can effectively extend the context window of existing embedding models by several folds, regardless of their original context being 512 or beyond 4k. Furthermore, for models employing absolute position encoding (APE), we show the possibility of further fine-tuning to harvest notable performance gains while strictly preserving original behavior for short inputs. For models using rotary position embedding (RoPE), significant enhancements are observed when em- ploying RoPE-specific methods, such as NTK and SelfExtend, indicating RoPE’s superiority over APE for context window extension. To facilitate future research, we release E5 Base-4k and E5-RoPE Base, along with the L ONG EMBED benchmark. QA SyntheticLongEmbed Needle Pass keySummScreenFDNarrativeQAQMSum 2WikimQASummarization (a) .25k .5k1k2k4k8k16k 32kContriever GTE E5 E5 +Tuning E5-RoPE E5-RoPE +SE Jina-V2 BGE-M3 Ada-002 E5-Mistral E5-Mistral+NTKAcc. on Passkey Test (b) 30405060708090 0.1k 1k 10k 100k E5-RoPEE5E5-MistralE5-Mistral +NTK E5 +TuningE5-RoPE +SEAvg. Score on LongEmbed 512 4k 32k (c) Figure 1: (a)Overview of the LONG EMBED benchmark. (b)Performance of current embedding models on passkey retrieval, with evaluation length ranging from 256 to 32,768.1▲/♦denotes embedding models with 512 / ≥4k context. The greener a cell is, the higher retrieval accuracy this model achieves on the corresponding evaluation length. (c)Effects of context window extension methods on E5, E5-RoPE, E5-Mistral, measured by improvements of Avg. Scores on LONGEMBED . SE / NTK is short for SelfExtend / NTK-Aware Interpolation. ∗Work done during Dawei’s internship at MSR Asia. Prof. Sujian Li is the corresponding author. 1For simplicity, we report results from the base versions of the included models by default. 1arXiv:2404.12096v1 [cs.CL] 18 Apr 2024
2103.06874.pdf
CANINE : Pre-training an Efficient Tokenization-Free Encoder for Language Representation Jonathan H. Clark, Dan Garrette, Iulia Turc, John Wieting Google Research {jhclark,dhgarrette,iuliaturc,jwieting}@google.com Abstract Pipelined NLP systems have largely been superseded by end-to-end neural model- ing, yet nearly all commonly-used models still require an explicit tokenization step. While recent tokenization approaches based on data-derived subword lexicons are less brittle than manually engineered tokenizers, these techniques are not equally suited to all languages, and the use of any fixed vocab- ulary may limit a model’s ability to adapt. In this paper, we present C ANINE , a neural encoder that operates directly on character sequences—without explicit tokenization or vocabulary—and a pre-training strategy that operates either directly on characters or op- tionally uses subwords as a soft inductive bias. To use its finer-grained input ef- fectively and efficiently, C ANINE combines downsampling, which reduces the input se- quence length, with a deep transformer stack, which encodes context. C ANINE out- performs a comparable mB ERT model by 5.7 F1 on T YDIQA, a challenging mul- tilingual benchmark, despite having fewer model parameters. 1 Introduction End-to-end neural models have generally replaced the traditional NLP pipeline, and with it, the error cascades and feature engineering common to such systems, preferring instead to let the model automatically induce its own sophisticated representations. Tokenization, however, is one of few holdovers from that era, with nearly all commonly-used models today requiring an ex- plicit preprocessing stage to segment a raw text CANINE :Character Architecture with No tokenization InNeural Encoders. Code and checkpoints are available on GitHub at http://caninemodel.page.link/code . Published in Transactions of the Association for Compu- tational Linguistics (TACL) , 2022.string into a sequence of discrete model inputs. Broadly speaking, tokenizers are generally either carefully constructed systems of language-specific rules, which are costly, requiring both manual feature engineering and linguistic expertise, or data-driven algorithms such as Byte Pair Encod- ing (Sennrich et al., 2016), WordPiece (Wu et al., 2016), or SentencePiece (Kudo and Richardson, 2018) that split strings based on frequencies in a corpus, which are less brittle and easier to scale, but are ultimately too simplistic to properly handle the wide range of linguistic phenomena that can’t be captured by mere string-splitting (§2.1). The degree of sophistication required to accu- rately capture the full breadth of linguistic phe- nomena, along with the infeasibility of writing such rules by hand across all languages and do- mains, suggests that explicit tokenization itself is problematic. In contrast, an end-to-end model that operates directly on raw text strings would avoid these issues, instead learning to compose in- dividual characters into its own arbitrarily com- plex features, with potential benefits for both ac- curacy and ease of use. While this change is con- ceptually very simple—one could replace the sub- word vocabulary in a model like B ERT (Devlin et al., 2019) with a vocabulary made solely of indi- vidual characters—doing so leads to two immedi- ate problems. First, the computational complexity of a transformer (Vaswani et al., 2017), the main components in B ERTas well as other models such as GPT (Radford et al., 2019; Brown et al., 2020) and T5 (Raffel et al., 2020), grows quadratically with the length of the input. Since standard sub- word models have roughly four characters per sub- word on average, the 4x increase in input sequence length would result is a significantly slower model. Second, simply switching to a character vocabu- lary yields empirically poor results (§4.2). In order to enable tokenization-free model- ing that overcomes these obstacles, we presentarXiv:2103.06874v4 [cs.CL] 18 May 2022
1810.12885.pdf
ReCoCoRD: Bridging the Gap between Human and Machine Commonsense Reading Comprehension Sheng Zhang†∗, Xiaodong Liu‡, Jingjing Liu‡, Jianfeng Gao‡, Kevin Duh†and Benjamin Van Durme† †Johns Hopkins University ‡Microsoft Research Abstract We present a large-scale dataset, ReCoRD, for machine reading comprehension requiring commonsense reasoning. Experiments on this dataset demonstrate that the performance of state-of-the-art MRC systems fall far behind human performance. ReCoRDrepresents a challenge for future research to bridge the gap between human and machine commonsense reading comprehension. ReCoRDis available athttp://nlp.jhu.edu/record . 1 Introduction Machine reading comprehension (MRC) is a cen- tral task in natural language understanding, with techniques lately driven by a surge of large-scale datasets (Hermann et al., 2015; Hill et al., 2015; Rajpurkar et al., 2016; Trischler et al., 2017; Nguyen et al., 2016), usually formalized as a task of answering questions given a passage. An in- creasing number of analyses (Jia and Liang, 2017; Rajpurkar et al., 2018; Kaushik and Lipton, 2018) have revealed that a large portion of questions in these datasets can be answered by simply match- ing the patterns between the question and the an- swer sentence in the passage. While systems may match or even outperform humans on these datasets, our intuition suggests that there are at least some instances in human reading compre- hension that require more than what existing chal- lenge tasks are emphasizing. One primary type of questions these datasets lack are the ones that require reasoning over common sense or under- standing across multiple sentences in the pas- sage (Rajpurkar et al., 2016; Trischler et al., 2017). To overcome this limitation, we introduce a large-scale dataset for reading comprehen- sion, ReCoRD (["rEk@rd] ), which consists of over 120,000 examples, most of which require ∗Work done when Sheng Zhang was visiting Microsoft. Passage (Cloze-style) QueryAccording to claims in the suit, "Parts of 'Stairway to Heaven,' instantly recognizable to the music fans across the world, sound almost identical to significant portions of ‘X.’”Reference AnswersTaurus(CNN) -- A lawsuit has been filed claiming that the iconic Led Zeppelin song "Stairway to Heaven" was far from original. The suit, filed on May 31 in the United States District Court Eastern District of Pennsylvania, was brought by the estate of the late musician Randy California against the surviving members of Led Zeppelin and their record label. The copyright infringement case alleges that the Zeppelin song was taken from the single "Taurus" by the 1960s band Spirit, for whom California served as lead guitarist. "Late in 1968, a then new band named Led Zeppelin began touring in the United States, opening for Spirit," the suit states. "It was during this time that Jimmy Page, Led Zeppelin's guitarist, grew familiar with 'Taurus' and the rest of Spirit's catalog. Page stated in interviews that he found Spirit to be 'very good' and that the band's performances struck him 'on an emotional level.' "• Suit claims similarities between two songs•Randy California was guitarist for the group Spirit•Jimmy Page has called the accusation "ridiculous"Figure 1: An example from ReCoRD. The passage is a snippet from a news article followed by some bullet points which summarize the news event. Named enti- ties highlighted in the passage are possible answers to the query. The query is a statement that is factually supported by the passage. Xin the statement indicates a missing named entity. The goal is to find the correct entity in the passage that best fits X. deep commonsense reasoning. ReCoRDis an acronym for the Reading Comprehension with Commonsense Reasoning Dataset. Figure 1 shows a ReCoRDexample: the pas- sage describes a lawsuit claiming that the band “Led Zeppelin ” had plagiarized the song “ Taurus ”arXiv:1810.12885v1 [cs.CL] 30 Oct 2018
2209.00626.pdf
arXiv:2209.00626v4 [cs.AI] 22 Feb 2023The Alignment Problem from a Deep Learning Perspective Richard Ngo OpenAI richard@openai.comLawrence Chan UC Berkeley (EECS) chanlaw@berkeley.eduSören Mindermann University of Oxford (CS) soren.mindermann@cs.ox.ac.uk Abstract Within the coming decades, artificial general intelligence (AGI) may surpass human capabilities at a wide range of important tasks. We outline a case for expecting tha t, without substantial effort to prevent it, AGIs could learn to pursue goals which are undesirable (i.e. misa ligned) from a human perspective. We argue that if AGIs are trained in ways similar to today’s most capable mo dels, they could learn to act deceptively to receive higher reward, learn internally-represented goal s which generalize beyond their training distributions, and pursue those goals using power-seeking strategies. We o utline how the deployment of misaligned AGIs might irreversibly undermine human control over the world, and briefly review research directions aimed at preventing this outcome. 1 Introduction Over the last decade, advances in deep learning have led to th e development of large neural networks with impressive capabilities in a wide range of domains. In addition to reach ing human-level performance on complex games like StarCraft 2 [ Vinyals et al. ,2019 ] and Diplomacy [ Bakhtin et al. ,2022 ], large neural networks show evidence of increasing generality [ Bommasani et al. ,2021 ], including advances in sample efficiency [ Brown et al. ,2020 ,Dorner , 2021 ], cross-task generalization [ Adam et al. ,2021 ], and multi-step reasoning [ Chowdhery et al. ,2022 ]. The rapid pace of these advances highlights the possibility that, wit hin the coming decades, we may develop artificial general intelligence (AGI)—that is, AI which can apply domain-gene ral cognitive skills (such as reasoning, memory, and planning) to perform at or above human level on a wide range of cognitive tasks relevant to the real world (such as writing software, formulating new scientific theories, or r unning a company) [ Goertzel ,2014 ].1This possibility is the aim of major research efforts [ OpenAI ,2023a ,DeepMind ,2023 ] and is taken seriously by leading ML researchers, who in two recent surveys gave median estimates of 2061 and 20 59 for the year in which AI will outperform humans at all tasks—although some expect this to occur much sooner o r later [ Grace et al. ,2018 ,Stein-Perlman et al. ,2022 ].2 The development of AGI could unlock many opportunities, but also comes with serious risks. One concern is known as the alignment problem : the challenge of ensuring that AI systems pursue goals that match human values or interests rather than unintended and undesirable goals [ Russell ,2019 ,Gabriel ,2020 ,Hendrycks et al. ,2020 ]. An increasing body of research aims to proactively address the alignment p roblem, motivated in large part by the desire to avoid hypothesized large-scale tail risks from AGIs that pursue u nintended goals [ OpenAI ,2023b ,Hendrycks and Mazeika , 2022 ,Amodei et al. ,2016 ,Hendrycks et al. ,2021 ]. Previous writings have argued that AGIs will be highly chall enging to robustly align, and that misaligned AGIs may pose accident risks on a sufficiently large scale to threaten human civilization [ Russell ,2019 ,Bostrom ,2014 ,Yud- kowsky ,2016 ,Carlsmith ,2022 ,Cohen et al. ,2022 ]. However, most of these writings only formulate their argu ments in terms of abstract high-level concepts (particularly con cepts from classical AI), without grounding them in modern machine learning techniques, while writings that focus on d eep learning techniques do so very informally, and with little engagement with the deep learning literature [ Ngo,2020 ,Cotra ,2022 ]. This raises the question of whether there are versions of these arguments which are relevant to, and empirically supported by, the modern deep learning paradigm. In this position paper, we hypothesize and defend factors th at could lead to large-scale risks if AGIs are trained using modern deep learning techniques. Specifically, we argue tha t pretraining AGIs using self-supervised learning and fine- tuning them using reinforcement learning from human feedba ck (RLHF) [ Christiano et al. ,2017 ] will plausibly lead to the emergence of three key properties. First, RLHF allows the possibility of situationally-aware reward hacking
2209.15571.pdf
Published as a conference paper at ICLR 2023 BUILDING NORMALIZING FLOWS WITH STOCHASTIC INTERPOLANTS Michael S. Albergo Center for Cosmology and Particle Physics New York University New York, NY 10003, USA albergo@nyu.eduEric Vanden-Eijnden Courant Institute of Mathematical Sciences New York University New York, NY 10012, USA eve2@cims.nyu.edu ABSTRACT A generative model based on a continuous-time normalizing flow between any pair of base and target probability densities is proposed. The velocity field of this flow is inferred from the probability current of a time-dependent density that in- terpolates between the base and the target in finite time. Unlike conventional nor- malizing flow inference methods based the maximum likelihood principle, which require costly backpropagation through ODE solvers, our interpolant approach leads to a simple quadratic loss for the velocity itself which is expressed in terms of expectations that are readily amenable to empirical estimation. The flow can be used to generate samples from either the base or target, and to estimate the like- lihood at any time along the interpolant. In addition, the flow can be optimized to minimize the path length of the interpolant density, thereby paving the way for building optimal transport maps. In situations where the base is a Gaussian den- sity, we also show that the velocity of our normalizing flow can also be used to construct a diffusion model to sample the target as well as estimate its score. How- ever, our approach shows that we can bypass this diffusion completely and work at the level of the probability flow with greater simplicity, opening an avenue for methods based solely on ordinary differential equations as an alternative to those based on stochastic differential equations. Benchmarking on density estimation tasks illustrates that the learned flow can match and surpass conventional contin- uous flows at a fraction of the cost, and compares well with diffusions on image generation on CIFAR-10 and ImageNet 32×32. The method scales ab-initio ODE flows to previously unreachable image resolutions, demonstrated up to 128×128. 1 I NTRODUCTION Contemporary generative models have primarily been designed around the construction of a map between two probability distributions that transform samples from the first into samples from the second. While progress has been from various angles with tools such as implicit maps (Goodfellow et al., 2014; Brock et al., 2019), and autoregressive maps (Menick & Kalchbrenner, 2019; Razavi et al., 2019; Lee et al., 2022), we focus on the case where the map has a clear associated probability flow. Advances in this domain, namely from flow and diffusion models, have arisen through the introduction of algorithms or inductive biases that make learning this map, and the Jacobian of the associated change of variables, more tractable. The challenge is to choose what structure to impose on the transport to best reach a complex target distribution from a simple one used as base, while maintaining computational efficiency. In the continuous time perspective, this problem can be framed as the design of a time-dependent map,Xt(x)witht∈[0,1], which functions as the push-forward of the base distribution at time t= 0 onto some time-dependent distribution that reaches the target at time t= 1. Assuming that these distributions have densities supported on Ω⊆Rd, sayρ0for the base and ρ1for the target, this amounts to constructing Xt: Ω→Ωsuch that ifx∼ρ0thenXt(x)∼ρtfor some density ρtsuch thatρt=0=ρ0andρt=1=ρ1. (1) 1arXiv:2209.15571v3 [cs.LG] 9 Mar 2023
2024.04.15.589672v1.full.pdf
DeProt: Protein language modeling with quantizied structure and disentangled attention Mingchen Li2,3† Yang Tan2,3† Bozitao Zhong1Ziyi Zhou1Huiqun Yu3 Xinzhu Ma2Wanli Ouyang2Liang Hong1,2∗Bingxin Zhou1∗Pan Tan1,2∗ 1Shanghai Jiao Tong University, China 2Shanghai Artificial Intelligence Laboratory, China 3East China University of Science and Technology, China {hongl3liang,bingxin.zhou,tpan1039}@sjtu.edu.cn Abstract Protein language models have exhibited remarkable representational capabilities in various downstream tasks, notably in the prediction of protein functions. Despite their success, these models traditionally grapple with a critical shortcoming: the absence of explicit protein structure information, which is pivotal for elucidating the relationship between protein sequences and their functionality. Addressing this gap, we introduce DeProt, a Transformer-based protein language model designed to incorporate protein sequences and structures. It was pre-trained on millions of protein structures from diverse natural protein clusters. DeProt first serializes pro- tein structures into residue-level local-structure sequences and use a graph neural network based auto-encoder to vectorized the local structures. Then, these vectors are quantized and formed a discrete structure tokens by a pre-trained codebook. Meanwhile, DeProt utilize disentangled attention mechanisms to effectively in- tegrate residue sequences with structure token sequences. Despite having fewer parameters and less training data, DeProt significantly outperforms other state-of- the-art (SOTA) protein language models, including those that are structure-aware and evolution-based, particularly in the task of zero-shot mutant effect prediction across 217 deep mutational scanning assays. Furthermore, DeProt exhibits robust representational capabilities across a spectrum of supervised-learning downstream tasks. Our comprehensive benchmarks underscore the innovative nature of De- Prot’s framework and its superior performance, suggesting its wide applicability in the realm of protein deep learning. For those interested in exploring DeProt further, the code, model weights, and all associated datasets are accessible at: https://github.com/ginnm/DeProt. 1 Introduction Proteins have a myriad of diverse functions that underlie the complexity of life [ 1]. Protein Language Models (PLMs), inspired from Natural Language Processing methods, have heralded a new era in bioinformatics and structural biology. These models have become indispensable tools for protein representation. They effectively capture the semantic and grammatical features inherent within protein sequences through unsupervised training on extensive sequence datasets. As the databases of protein sequences have grown exponentially over the past decades, data-driven approaches for modeling proteins at scale made substantial progress. These PLMs have been trained on diverse protein sequence databases and different unsupervised objectives. They have shown remarkable proficiency in various protein related tasks. ∗Corresponding authors. †Equal contribution. Preprint. Under review.. CC-BY-NC-ND 4.0 International license available under awas not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made The copyright holder for this preprint (which this version posted April 17, 2024. ; https://doi.org/10.1101/2024.04.15.589672doi: bioRxiv preprint
2307.09288.pdf
Llama 2 : Open Foundation and Fine-Tuned Chat Models Hugo Touvron∗Louis Martin†Kevin Stone† Peter Albert Amjad Almahairi Yasmine Babaei Nikolay Bashlykov Soumya Batra Prajjwal Bhargava Shruti Bhosale Dan Bikel Lukas Blecher Cristian Canton Ferrer Moya Chen Guillem Cucurull David Esiobu Jude Fernandes Jeremy Fu Wenyin Fu Brian Fuller Cynthia Gao Vedanuj Goswami Naman Goyal Anthony Hartshorn Saghar Hosseini Rui Hou Hakan Inan Marcin Kardas Viktor Kerkez Madian Khabsa Isabel Kloumann Artem Korenev Punit Singh Koura Marie-Anne Lachaux Thibaut Lavril Jenya Lee Diana Liskovich Yinghai Lu Yuning Mao Xavier Martinet Todor Mihaylov Pushkar Mishra Igor Molybog Yixin Nie Andrew Poulton Jeremy Reizenstein Rashi Rungta Kalyan Saladi Alan Schelten Ruan Silva Eric Michael Smith Ranjan Subramanian Xiaoqing Ellen Tan Binh Tang Ross Taylor Adina Williams Jian Xiang Kuan Puxin Xu Zheng Yan Iliyan Zarov Yuchen Zhang Angela Fan Melanie Kambadur Sharan Narang Aurelien Rodriguez Robert Stojnic Sergey Edunov Thomas Scialom∗ GenAI, Meta Abstract In this work, we develop and release Llama 2, a collection of pretrained and fine-tuned large language models (LLMs) ranging in scale from 7 billion to 70 billion parameters. Our fine-tuned LLMs, called Llama 2-Chat , are optimized for dialogue use cases. Our models outperform open-source chat models on most benchmarks we tested, and based on ourhumanevaluationsforhelpfulnessandsafety,maybeasuitablesubstituteforclosed- source models. We provide a detailed description of our approach to fine-tuning and safety improvements of Llama 2-Chat in order to enable the community to build on our work and contribute to the responsible development of LLMs. ∗Equal contribution, corresponding authors: {tscialom, htouvron}@meta.com †Second author Contributions for all the authors can be found in Section A.1.arXiv:2307.09288v2 [cs.CL] 19 Jul 2023
2306.07629.pdf
SqueezeLLM: Dense-and-Sparse Quantization Sehoon Kim∗ sehoonkim@berkeley.edu UC BerkeleyColeman Hooper∗ chooper@berkeley.edu UC BerkeleyAmir Gholami∗† amirgh@berkeley.edu ICSI, UC Berkeley Zhen Dong zhendong@berkeley.edu UC BerkeleyXiuyu Li xiuyu@berkeley.edu UC BerkeleySheng Shen sheng.s@berkeley.edu UC Berkeley Michael W. Mahoney mmahoney@stat.berkeley.edu ICSI, LBNL, UC BerkeleyKurt Keutzer keutzer@berkeley.edu UC Berkeley ABSTRACT Generative Large Language Models (LLMs) have demonstrated re- markable results for a wide range of tasks. However, deploying these models for inference has been a significant challenge due to their unprecedented resource requirements. This has forced exist- ing deployment frameworks to use multi-GPU inference pipelines, which are often complex and costly, or to use smaller and less performant models. In this work, we demonstrate that the main bot- tleneck for generative inference with LLMs is memory bandwidth, rather than compute, specifically for single batch inference. While quantization has emerged as a promising solution by representing weights with reduced precision, previous efforts have often resulted in notable performance degradation. To address this, we introduce SqueezeLLM, a post-training quantization framework that not only enables lossless compression to ultra-low precisions of up to 3-bit, but also achieves higher quantization performance under the same memory constraint. Our framework incorporates two novel ideas: (i)sensitivity-based non-uniform quantization , which searches for the optimal bit precision assignment based on second-order in- formation; and (ii) the Dense-and-Sparse decomposition that stores outliers and sensitive weight values in an efficient sparse format. When applied to the LLaMA models, our 3-bit quantization signifi- cantly reduces the perplexity gap from the FP16 baseline by up to 2.1×as compared to the state-of-the-art methods with the same memory requirement. Furthermore, when deployed on an A6000 GPU, our quantized models achieve up to 2.3 ×speedup compared to the baseline. Our code is open-sourced and available online1. 1 INTRODUCTION Recent advances in Large Language Models (LLMs), with up to hundreds of billions of parameters and trained on massive text cor- pora, have showcased their remarkable problem-solving capabilities across various domains [ 4,10,16,30,51,53,57,62,64,84,84]. How- ever, deploying these models for inference has been a significant challenge due to their demanding resource requirements. For in- stance, the LLaMA-65B [ 63] model requires at least 130GB of RAM to deploy in FP16, and this exceeds current GPU capacity. Even storing such large-sized models has become costly and complex. ∗Equal contribution †Corresponding author 1https://github.com/SqueezeAILab/SqueezeLLMAs will be discussed in Sec. 3, the main performance bottleneck in LLM inference for generative tasks is memory bandwidth rather than compute. This means that the speed at which we can load and store parameters becomes the primary latency bottleneck for memory-bound problems, rather than arithmetic computations. However, recent advancements in memory bandwidth technology have been significantly slow compared to the improvements in com- putes, leading to the phenomenon known as the Memory Wall [ 50]. Consequently, researchers have turned their attention to exploring algorithmic methods to overcome this challenge. One promising approach is quantization, where model parame- ters are stored at lower precision, instead of the typical 16 or 32-bit precision used for training. For instance, it has been demonstrated that LLM models can be stored in 8-bit precision without incurring performance degradation [ 75], where 8-bit quantization not only reduces the storage requirements by half but also has the potential to improve inference latency and throughput. As a result, there has been significant research interest in quantizing models to even lower precisions. A pioneering approach is GPTQ [ 19] which uses a training-free quantization technique that achieves near-lossless 4-bit quantization for large LLM models with over tens of billions of parameters. However, achieving high quantization performance remains challenging, particularly with lower bit precision and for relatively smaller models (e.g., <50B parameters) such as the recent LLaMA [64] or its instruction-following variants [8, 22, 61]. In this paper, we conduct an extensive study of low-bit precision quantization and identify limitations in existing approaches. Build- ing upon these insights, we propose a novel solution that achieves lossless compression and improved quantization performance for models of the same size, even at precisions as low as 3 bits. Contributions. We start by presenting performance modeling re- sults demonstrating that the memory, rather than the compute, is the primary bottleneck in LLM inference with generative tasks. Building on this insight, we introduce SqueezeLLM, a post-training quantization framework that incorporates a novel sensitivity-based non-uniform quantization technique and a Dense-and-Sparse decom- position method. These techniques enable ultra-low-bit precision quantization, while maintaining competitive model performance, significantly reducing the model sizes and inference time costs. In more detail, our main contributions can be summarized as follows:arXiv:2306.07629v1 [cs.CL] 13 Jun 2023
2205.15317.pdf
Chefs’ Random Tables: Non-Trigonometric Random Features Valerii Likhosherstov* University of Cambridge vl304@cam.ac.ukKrzysztof Choromanski* Google Research & Columbia University kchoro@google.comAvinava Dubey* Google Research Frederick Liu* Google ResearchTamas Sarlos Google ResearchAdrian Weller University of Cambridge & The Alan Turing Institute Abstract We introduce chefs’ random tables (CRTs), a new class of non-trigonometric random features (RFs) to approximate Gaussian and softmax-kernels. CRTs are an alternative to standard random kitchen sink (RKS) methods, which inherently rely on the trigonometric maps [ 41]. We present variants of CRTs where RFs are positive, a key requirement for applications in recent low-rank Transformers [ 13]. Further variance reduction is possible by leveraging statistics which are simple to compute. One instantiation of CRTs, the optimal positive random features (OPRFs), is to our knowledge the first RF method for unbiased softmax-kernel estimation with positive and bounded RFs, resulting in exponentially small tails and much lower variance than its counterparts. As we show, orthogonal random features applied in OPRFs provide additional variance reduction for any dimensionality d (not only asymptotically for sufficiently large d, as for RKS). We test CRTs on many tasks ranging from non-parametric classification to training Transformers for text, speech and image data, obtaining new state-of-the-art results for low-rank text Transformers, while providing linear space and time complexity of the attention. 1 Introduction & related work The idea that nonlinear mappings of the random-weight linear combinations of data features can be used to linearize various nonlinear similarity functions transformed kernel methods. This led to the development of Random Kitchen Sinks (RKSs) techniques; and the new field of scalable kernel algorithms, introduced in the paper trilogy [ 39,40,41], was born. RKSs were subsequently used in many applications, ranging from kernel and function-to-function regression [ 1,30,37], SVM algorithms [ 45] to operator-valued and semigroup kernels [ 33,52], neural networks [ 23,51,9,25] and even differentially-private ML algorithms [ 8], as well as (very recently) nonparametric adaptive control [3]. Random features (RFs) are a subject of much theoretical analysis [31, 53, 46, 43]. To approximate shift invariant (e.g. Gaussian, Cauchy or Laplace) and softmax kernels, RKSs rely on the trigonometric nonlinear mappings provided directly by Bochner’s Theorem [ 33]. Trigonometric RFs provide strong concentration results (e.g. uniform convergence, see Claim 1 in [ 40]), but suffer from a weakness that was noted recently – they are not guaranteed to be positive. This makes them unsuitable for approximating softmax-attention in scalable Transformers relying on implicit attention via random features [ 13]. As noted in [ 13], trigonometric features lead to unstable training, as they yield poor approximations of the partition functions applied to renormalize attention and involving * Equal contribution Preprint. Under review.arXiv:2205.15317v1 [cs.LG] 30 May 2022