GenAI4ELab/papercli-papers huggingface dataset:
Planning with Large Language Models for Code Generation
Authors: Shun Zhang; Zhenfang Chen; Yikang Shen; Mingyu Ding; Joshua B. Tenenbaum; Chuang Gan
Venue: ICLR 2023 (ICLR 2023 poster)

Abstract: Existing large language model-based code generation pipelines typically use beam search or sampling algorithms during the decoding process. Although the programs they generate achieve high token-matching-based scores, they often fail to compile or generate incorrect outputs. The main reason is that conventional Transformer decoding algorithms may not be the best choice for code generation. In this work, we propose a novel Transformer decoding algorithm, Planning-Guided Transformer Decoding (PG-TD), that uses a planning algorithm to do lookahead search and guide the Transformer to generate better programs. Specifically, instead of simply optimizing the likelihood of the generated sequences, the Transformer makes use of a planner that generates candidate programs and tests them on public test cases. The Transformer can therefore make more informed decisions and generate tokens that will eventually lead to higher-quality programs. We also design a mechanism that shares information between the Transformer and the planner to make our algorithm computationally efficient. We empirically evaluate our framework with several large language models as backbones on public coding challenge benchmarks, showing that 1) it can generate programs that consistently achieve higher performance compared with competing baseline methods; 2) it enables controllable code generation, such as concise codes and highly-commented codes by optimizing modified objective.
Preserving Semantics in Textual Adversarial Attacks
Authors: David Herel; Hugo Cisneros; Tomas Mikolov
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Adversarial attacks in NLP challenge the way we look at language models. The goal of this kind of adversarial attack is to modify the input text to fool a classifier while maintaining the original meaning of the text. Although most existing adversarial attacks claim to fulfill the constraint of semantics preservation, careful scrutiny shows otherwise. We show that the problem lies in the text encoders used to determine the similarity of adversarial examples, specifically in the way they are trained. Unsupervised training methods make these encoders more susceptible to problems with antonym recognition. To overcome this, we introduce a simple, fully supervised sentence embedding technique called Semantics-Preserving-Encoder (SPE). The results show that our solution minimizes the variation in the meaning of the adversarial examples generated. It also significantly improves the overall quality of adversarial examples, as confirmed by human evaluators. Furthermore, it can be used as a component in any existing attack to speed up its execution while maintaining similar attack success.
Fast Sampling of Diffusion Models with Exponential Integrator
Authors: Qinsheng Zhang; Yongxin Chen
Venue: ICLR 2023 (ICLR 2023 poster)

Abstract: The past few years have witnessed the great success of Diffusion models~(DMs) in generating high-fidelity samples in generative modeling tasks. A major limitation of the DM is its notoriously slow sampling procedure which normally requires hundreds to thousands of time discretization steps of the learned diffusion process to reach the desired accuracy. Our goal is to develop a fast sampling method for DMs with a much less number of steps while retaining high sample quality. To this end, we systematically analyze the sampling procedure in DMs and identify key factors that affect the sample quality, among which the method of discretization is most crucial. By carefully examining the learned diffusion process, we propose Diffusion Exponential Integrator Sampler~(DEIS). It is based on the Exponential Integrator designed for discretizing ordinary differential equations (ODEs) and leverages a semilinear structure of the learned diffusion process to reduce the discretization error. The proposed method can be applied to any DMs and can generate high-fidelity samples in as few as 10 steps. Moreover, by directly using pre-trained DMs, we achieve state-of-art sampling performance when the number of score function evaluation~(NFE) is limited,  e.g., 4.17 FID with 10 NFEs, 2.86 FID with only 20 NFEs on CIFAR10.
Challenging Common Assumptions about Catastrophic Forgetting
Authors: Timothee LESORT; Oleksiy Ostapenko; Pau Rodriguez; Md Rifat Arefin; Diganta Misra; Laurent Charlin; Irina Rish
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Standard gradient descent algorithms applied to sequences of tasks are known to induce catastrophic forgetting in deep neural networks. When trained on a new task, the model's parameters are updated in a way that degrades performance on past tasks. 
This article explores continual learning (CL) on long sequences of tasks sampled from a finite environment.
\textbf{We show that in this setting, learning with stochastic gradient descent (SGD) results in knowledge retention and accumulation without specific memorization mechanisms.} This is in contrast to the current notion of forgetting from the CL literature, which shows that training on new tasks with such an approach results in forgetting previous tasks, especially in class-incremental settings.
To study this phenomenon, we propose an experimental framework, \Scole{} (Scaling Continual Learning), which allows to generate arbitrarily long task sequences. Our experiments show that the previous results obtained on relatively short task sequences may not reveal certain phenomena that emerge in longer ones.
Stealing and Defending Transformer-based Encoders
Authors: Adam Dziedzic; Franziska Boenisch; Mingjian Jiang; Haonan Duan; Nicolas Papernot
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Self-supervised learning (SSL) has become the predominant approach to training on large amounts of unlabeled data. New real-world APIs offer services to generate high-dimensional representations for given inputs based on SSL encoders with transformer architectures. Recent efforts highlight that it is possible to steal high-quality SSL encoders trained on convolutional neural networks. In this work, we are the first to extend this line of work to stealing and defending transformer-based encoders in both language and vision domains. We show that it is possible to steal transformer-based sentence embedding models solely using their returned representations and with 40x fewer queries than the number of victim's training data points.  We also decrease the number of required stealing queries for the vision encoders by leveraging semi-supervised learning. Finally, to defend vision transformers against stealing attacks, we propose a defense technique that combines watermarking with dataset inference. Our method creates a unique encoder signature based on a private data subset that acts as a secret seed during training. By applying dataset inference on the seed, we can then successfully identify stolen transformers.
Empowering Graph Representation Learning with Test-Time Graph Transformation
Authors: Wei Jin; Tong Zhao; Jiayuan Ding; Yozen Liu; Jiliang Tang; Neil Shah
Venue: ICLR 2023 (ICLR 2023 poster)

Abstract: As powerful tools for representation learning on graphs, graph neural networks (GNNs) have facilitated various applications from drug discovery to recommender systems. Nevertheless, the effectiveness of GNNs is immensely challenged by issues related to data quality, such as distribution shift, abnormal features and adversarial attacks. Recent efforts have been made on tackling these issues from a modeling perspective which requires additional cost of changing model architectures or re-training model parameters. In this work, we provide a data-centric view to tackle these issues and propose a graph transformation framework named GTrans which adapts and refines graph data at test time to achieve better performance. We provide theoretical analysis on the design of the framework and discuss why adapting graph data works better than adapting the model. Extensive experiments have demonstrated the effectiveness of GTrans on three distinct scenarios for eight benchmark datasets where suboptimal data is presented. Remarkably, GTrans performs the best in most cases with improvements up to 2.8%, 8.2% and 3.8% over the best baselines on three experimental settings.
HIVE: HIerarchical Volume Encoding for Neural Implicit Surface Reconstruction
Authors: Xiaodong Gu; Weihao Yuan; Heng Li; Zilong Dong; Ping Tan
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Neural implicit surface reconstruction has become a new trend in reconstructing a detailed 3D shape from images. In previous methods, however, the 3D scene is only encoded by the MLPs which do not have an explicit 3D structure. To better represent 3D shapes, we introduce a volume encoding to explicitly encode the spatial information. We further design hierarchical volumes to encode the scene structures in multiple scales. The high-resolution volumes capture the high-frequency geometry details since spatially varying features could be learned from different 3D points, while the low-resolution volumes enforce the spatial consistency to keep the shape smooth since adjacent locations possess the same low-resolution feature. In addition, we adopt a sparse structure to reduce the memory consumption at high-resolution volumes, and two regularization terms to enhance results smoothness. This hierarchical volume encoding could be appended to any implicit surface reconstruction method as a plug-and-play module, and can generate a smooth and clean reconstruction with more details. Superior performance is demonstrated in DTU, EPFL, and BlendedMVS datasets with significant improvement on the standard metrics. The code of our method will be made public.
Training A Multi-stage Deep Classifier with Feedback Signals
Authors: Chao Xu; Yu Yang; Rongzhao Wang; Guan Wang; Bojia Lin
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Multi-Stage Classifier (MSC) - several classifiers working sequentially in an arranged order and classification decision is partially made at each step - is widely used in industrial applications for various resource limitation reasons. The classifiers of a multi-stage process are usually Neural Network (NN) models trained independently or in their inference order without considering the signals from the latter stages. Aimed at two-stage binary classification process, the most common type of MSC, we propose a novel training framework, named Feedback Training. The classifiers are trained in an order reverse to their actual working order, and the classifier at the later stage is used to guide the training of initial-stage classifier via a sample weighting method. We experimentally show the efficacy of our proposed approach, and its great superiority under the scenario of few-shot training.
KeyCLD: Learning Constrained Lagrangian Dynamics in Keypoint Coordinates from Images
Authors: Rembert Daems; Jeroen Taets; Francis wyffels; Guillaume Crevecoeur
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: We present KeyCLD, a framework to learn Lagrangian dynamics from images. Learned keypoint representations derived from images are directly used as positional state vector for jointly learning constrained Lagrangian dynamics. KeyCLD is trained unsupervised end-to-end on sequences of images. Our method explicitly models the mass matrix, potential energy and the input matrix, thus allowing energy based control. We demonstrate learning of Lagrangian dynamics from images on the dm_control pendulum, cartpole and acrobot environments, wether they are unactuated, underactuated or fully actuated. Trained models are able to produce long-term video predictions, showing that the dynamics are accurately learned. Our method strongly outperforms recent works on learning Lagrangian or Hamiltonian dynamics from images. The benefits of including a Lagrangian prior and prior knowledge of a constraint function is further investigated and empirically evaluated.
The Biased Artist: Exploiting Cultural Biases via Homoglyphs in Text-Guided Image Generation Models
Authors: Lukas Struppek; Dominik Hintersdorf; Kristian Kersting
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Text-guided image generation models, such as DALL-E2 and Stable Diffusion, have recently received much attention from academia and the general public. Provided with textual descriptions, these models are capable of generating high-quality images depicting various concepts and styles. However, such models are trained on large amounts of public data and implicitly learn relationships from their training data that are not immediately apparent. We demonstrate that common multimodal models implicitly learned cultural biases that can be triggered and injected into the generated images by simply replacing single characters in the textual description with visually similar non-Latin characters. These so-called homoglyph replacements enable malicious users or service providers to induce biases into the generated images and even render the whole generation process useless. We practically illustrate such attacks on DALL-E2 and Stable Diffusion as text-guided image generation models and further show that CLIP also behaves similarly. Our results further indicate that text encoders trained on multilingual data provide a way to mitigate the effects of homoglyph replacements.
How robust is unsupervised representation learning to distribution shift?
Authors: Yuge Shi; Imant Daunhawer; Julia E Vogt; Philip Torr; Amartya Sanyal
Venue: ICLR 2023 (ICLR 2023 poster)

Abstract: The robustness of machine learning algorithms to distributions shift is primarily discussed in the context of supervised learning (SL). As such, there is a lack of insight on the robustness of the representations learned from unsupervised methods, such as self-supervised learning (SSL) and auto-encoder based algorithms (AE), to distribution shift. We posit that the input-driven objectives of unsupervised algorithms lead to representations that are more robust to distribution shift than the target-driven objective of SL. We verify this by extensively evaluating the performance of SSL and AE on both synthetic and realistic distribution shift datasets. Following observations that the linear layer used for classification itself can be susceptible to spurious correlations, we evaluate the representations using a linear
head trained on a small amount of out-of-distribution (OOD) data, to isolate the robustness of the learned representations from that of the linear head. We also develop “controllable” versions of existing realistic domain generalisation datasets with adjustable degrees of distribution shifts. This allows us to study the robustness of different learning algorithms under versatile yet realistic distribution shift
conditions. Our experiments show that representations learned from unsupervised learning algorithms generalise better than SL under a wide variety of extreme as well as realistic distribution shifts.
G-Censor: Graph Contrastive Learning with Task-Oriented Counterfactual Views
Authors: tianqianjin lin; Yangyang Kang; Zhuoren Jiang; Xurui Li; Changlong Sun; cui huang; Xiaozhong Liu
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Graph Contrastive learning (GCL) has achieved great success in learning representations from unlabeled graph-structure data. However, how to automatically obtain the optimal contrastive views w.r.t specific downstream tasks is little studied. Theoretically, a downstream task can be causally correlated to particular sub-structures in graphs. The existing GCL methods may fail to enhance model performance on a given task when the task-related semantics are incomplete/preserved in the positive/negative views. To address this problem, we propose G-CENSOR, i.e., Graph Contrastive lEarniNg with taSk-oriented cOunteRfactual views, a model-agnostic framework designed for node property prediction tasks. G-CENSOR can simultaneously generate the optimal task-oriented counterfactual positive/negative views for raw ego-graphs and train graph neural networks (GNNs) with a contrastive objective between the raw ego-graphs and their corresponding counterfac-tual views. Extensive experiments on eight real-world datasets demonstrate that G-CENSOR can consistently outperform existing state-of-the-art GCL methods to improve the task performance and generalizability of a series of typical GNNs. To the best of our knowledge, this is a pioneer investigation to explore task-oriented graph contrastive learning from a counterfactual perspective in node property pre- diction tasks. We will release the source code after the review process.
Adversarial Training of Self-supervised Monocular Depth Estimation against Physical-World Attacks
Authors: Zhiyuan Cheng; James Chenhao Liang; Guanhong Tao; Dongfang Liu; Xiangyu Zhang
Venue: ICLR 2023 (ICLR 2023 notable top 25%)

Abstract: Monocular Depth Estimation (MDE) is a critical component in applications such as autonomous driving. There are various attacks against MDE networks. These attacks, especially the physical ones, pose a great threat to the security of such systems.  Traditional adversarial training method requires ground-truth labels and hence cannot be directly applied to self-supervised MDE that does not have depth ground truth. Some self-supervised model hardening technique (e.g., contrastive learning) ignores the domain knowledge of MDE and can hardly achieve optimal performance. In this work, we propose a novel adversarial training method for self-supervised MDE models based on view synthesis without using the depth ground truth. We improve adversarial robustness against physical-world attacks using $L_0$-norm-bounded perturbation in training. We compare our method with supervised learning-based and contrastive learning-based methods that are tailored for MDE. Results on two representative MDE networks show that we achieve better robustness against various adversarial attacks with nearly no benign performance degradation.
Learning to Cooperate and Communicate Over Imperfect Channels
Authors: Jannis Weil; Gizem Ekinci; Heinz Koeppl; Tobias Meuser
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Information exchange in multi-agent systems improves the cooperation among agents, especially in partially observable settings. This can be seen as part of the problem in which the agents learn how to communicate and to solve a shared task simultaneously. In the real world, communication is often carried out over imperfect channels and this requires the agents to deal with uncertainty due to potential information loss. In this paper, we consider a cooperative multi-agent system where the agents act and exchange information in a decentralized manner using a limited and unreliable channel. To cope with such channel constraints, we propose a novel communication approach based on independent Q-learning. Our method allows agents to dynamically adapt how much information to share by sending messages of different size, depending on their local observations and the channel properties. In addition to this message size selection, agents learn to encode and decode messages to improve their policies. We show that our approach outperforms approaches without adaptive capabilities and discuss its limitations in different environments.
ProtoGNN: Prototype-Assisted Message Passing Framework for Non-Homophilous Graphs
Authors: Yanfei Dong; Mohammed Haroon Dupty; Lambert Deng; Yong Liang Goh; Wee Sun Lee
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Many well-known Graph Neural Network (GNN) models assume the underlying graphs are homophilous, where nodes share similar features and labels with their neighbours. They rely on message passing that iteratively aggregates neighbour's features and often suffer performance degradation on non-homophilous graphs where useful information is hardly available in the local neighbourhood. In addition, earlier studies show that in some cases GNNs are even outperformed by Multi-Layer Perceptron, indicating insufficient exploitation of node feature information. Motivated by the two limitations, we propose ProtoGNN, a novel message passing framework that augments existing GNNs by effectively combining node features with structural information. ProtoGNN learns multiple class prototypes for each class from raw node features with the slot-attention mechanism. These prototype representations are then transferred onto the structural node features with explicit message passing to all non-training nodes irrespective of distance. This form of message passing, from training nodes to class prototypes to non-training nodes, also serves as a shortcut that bypasses local graph neighbourhoods and captures global information. ProtoGNN is a generic framework which can be applied onto any of the existing GNN backbones to improve node representations when node features are strong and local graph information is scarce. We demonstrate through extensive experiments that ProtoGNN brings performance improvement to various GNN backbones and achieves state-of-the-art on several non-homophilous datasets.
Holographic-(V)AE: an end-to-end SO(3)-Equivariant (Variational) Autoencoder in Fourier Space
Authors: Gian Marco Visani; Michael Neal Pun; Armita Nourmohammad
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: Group-equivariant neural networks have emerged as a data-efficient approach to solve classification and regression tasks, while respecting the relevant symmetries of the data. However, little work has been done to extend this paradigm to the unsupervised and generative domains. Here, we present Holographic-(V)AE (H-(V)AE), a fully end-to-end SO(3)-equivariant (variational) autoencoder in Fourier space, suitable for unsupervised learning and generation of data distributed around a specified origin. H-(V)AE is trained to reconstruct the spherical Fourier encoding of data, learning in the process a latent space with a maximally informative invariant embedding alongside an equivariant frame describing the orientation of the data. We extensively test the performance of H-(V)AE on diverse datasets and show that its latent space efficiently encodes the categorical features of spherical images and structural features of protein atomic environments. Our work can further be seen as a case study for equivariant modeling of a data distribution by reconstructing its Fourier encoding.
LEARNING DYNAMIC ABSTRACT REPRESENTATIONS FOR SAMPLE-EFFICIENT REINFORCEMENT LEARNING
Authors: Mehdi Dadvar; Rashmeet Kaur Nayyar; Siddharth Srivastava
Venue: ICLR 2023 (Submitted to ICLR 2023)

Abstract: In many real-world problems, the learning agent needs to learn a problem’s abstractions and solution simultaneously. However, most such abstractions need to be designed and refined by hand for different problems and domains of application. This paper presents a novel top-down approach for constructing state abstractions while carrying out reinforcement learning. Starting with state variables and a simulator, it presents a novel domain-independent approach for dynamically computing an abstraction based on the dispersion of Q-values in abstract states as the agent continues acting and learning. Extensive empirical evaluation on multiple domains and problems shows that this approach automatically learns abstractions that are finely-tuned to the problem, yield powerful sample efficiency, and result in the RL agent significantly outperforming existing approaches.