Deep Learning
Analysis of memory consumption by neural networks based on hyperparameters
Deep learning models are trained and deployed in multiple domains. Increasing usage of deep learning models alarms the usage of memory consumed while computation by deep learning models. Existing approaches for reducing memory consumption like model compression, hardware changes are specific. We propose a generic analysis of memory consumption while training deep learning models in comparison with hyperparameters used for training. Hyperparameters which includes the learning rate, batchsize, number of hidden layers and depth of layers decide the model performance, accuracy of the model. We assume the optimizers and type of hidden layers as a known values. The change in hyperparamaters and the number of hidden layers are the variables considered in this proposed approach. For better understanding of the computation cost, this proposed analysis studies the change in memory consumption with respect to hyperparameters as main focus. This results in general analysis of memory consumption changes during training when set of hyperparameters are altered.
Statistical discrimination in learning agents
Duéñez-Guzmán, Edgar A., McKee, Kevin R., Mao, Yiran, Coppin, Ben, Chiappa, Silvia, Vezhnevets, Alexander Sasha, Bakker, Michiel A., Bachrach, Yoram, Sadedin, Suzanne, Isaac, William, Tuyls, Karl, Leibo, Joel Z.
Undesired bias afflicts both human and algorithmic decision making, and may be especially prevalent when information processing trade-offs incentivize the use of heuristics. One primary example is \textit{statistical discrimination} -- selecting social partners based not on their underlying attributes, but on readily perceptible characteristics that covary with their suitability for the task at hand. We present a theoretical model to examine how information processing influences statistical discrimination and test its predictions using multi-agent reinforcement learning with various agent architectures in a partner choice-based social dilemma. As predicted, statistical discrimination emerges in agent policies as a function of both the bias in the training population and of agent architecture. All agents showed substantial statistical discrimination, defaulting to using the readily available correlates instead of the outcome relevant features. We show that less discrimination emerges with agents that use recurrent neural networks, and when their training environment has less bias. However, all agent algorithms we tried still exhibited substantial bias after learning in biased training populations.
Generalized Out-of-Distribution Detection: A Survey
Yang, Jingkang, Zhou, Kaiyang, Li, Yixuan, Liu, Ziwei
Out-of-distribution (OOD) detection is critical to ensuring the reliability and safety of machine learning systems. For instance, in autonomous driving, we would like the driving system to issue an alert and hand over the control to humans when it detects unusual scenes or objects that it has never seen before and cannot make a safe decision. This problem first emerged in 2017 and since then has received increasing attention from the research community, leading to a plethora of methods developed, ranging from classification-based to density-based to distance-based ones. Meanwhile, several other problems are closely related to OOD detection in terms of motivation and methodology. These include anomaly detection (AD), novelty detection (ND), open set recognition (OSR), and outlier detection (OD). Despite having different definitions and problem settings, these problems often confuse readers and practitioners, and as a result, some existing studies misuse terms. In this survey, we first present a generic framework called generalized OOD detection, which encompasses the five aforementioned problems, i.e., AD, ND, OSR, OOD detection, and OD. Under our framework, these five problems can be seen as special cases or sub-tasks, and are easier to distinguish. Then, we conduct a thorough review of each of the five areas by summarizing their recent technical developments. We conclude this survey with open challenges and potential research directions.
Fast Model Editing at Scale
Mitchell, Eric, Lin, Charles, Bosselut, Antoine, Finn, Chelsea, Manning, Christopher D.
While large pre-trained models have enabled impressive results on a variety of downstream tasks, the largest existing models still make errors, and even accurate predictions may become outdated over time. Because detecting all such failures at training time is impossible, enabling both developers and end users of such models to correct inaccurate outputs while leaving the model otherwise intact is desirable. However, the distributed, black-box nature of the representations learned by large neural networks makes producing such targeted edits difficult. If presented with only a single problematic input and new desired output, fine-tuning approaches tend to overfit; other editing algorithms are either computationally infeasible or simply ineffective when applied to very large models. To enable easy post-hoc editing at scale, we propose Model Editor Networks with Gradient Decomposition (MEND), a collection of small auxiliary editing networks that use a single desired input-output pair to make fast, local edits to a pre-trained model. MEND learns to transform the gradient obtained by standard fine-tuning, using a low-rank decomposition of the gradient to make the parameterization of this transformation tractable. MEND can be trained on a single GPU in less than a day even for 10 billion parameter models; once trained MEND enables rapid application of new edits to the pre-trained model. Our experiments with T5, GPT, BERT, and BART models show that MEND is the only approach to model editing that produces effective edits for models with tens of millions to over 10 billion parameters. Increasingly large neural networks have become a fundamental tool in solving data-driven problems in computer vision (Huang et al., 2017) and natural language processing (Vaswani et al., 2017) in particular. However, a key challenge in deploying and maintaining such models is issuing patches to adjust model behavior after deployment (Sinitsin et al., 2020).
OpenABC-D: A Large-Scale Dataset For Machine Learning Guided Integrated Circuit Synthesis
Chowdhury, Animesh Basak, Tan, Benjamin, Karri, Ramesh, Garg, Siddharth
Logic synthesis is a challenging and widely-researched combinatorial optimization problem during integrated circuit (IC) design. It transforms a high-level description of hardware in a programming language like Verilog into an optimized digital circuit netlist, a network of interconnected Boolean logic gates, that implements the function. Spurred by the success of ML in solving combinatorial and graph problems in other domains, there is growing interest in the design of ML-guided logic synthesis tools. Yet, there are no standard datasets or prototypical learning tasks defined for this problem domain. Here, we describe OpenABC-D,a large-scale, labeled dataset produced by synthesizing open source designs with a leading open-source logic synthesis tool and illustrate its use in developing, evaluating and benchmarking ML-guided logic synthesis. OpenABC-D has intermediate and final outputs in the form of 870,000 And-Inverter-Graphs (AIGs) produced from 1500 synthesis runs plus labels such as the optimized node counts, and de-lay. We define a generic learning problem on this dataset and benchmark existing solutions for it. The codes related to dataset creation and benchmark models are available athttps://github.com/NYU-MLDA/OpenABC.git. The dataset generated is available athttps://archive.nyu.edu/handle/2451/63311
Variational Predictive Routing with Nested Subjective Timescales
Zakharov, Alexey, Guo, Qinghai, Fountas, Zafeirios
Discovery and learning of an underlying spatiotemporal hierarchy in sequential data is an important topic for machine learning. Despite this, little work has been done to explore hierarchical generative models that can flexibly adapt their layerwise representations in response to datasets with different temporal dynamics. Here, we present Variational Predictive Routing (VPR) - a neural probabilistic inference system that organizes latent representations of video features in a temporal hierarchy, based on their rates of change, thus modeling continuous data as a hierarchical renewal process. By employing an event detection mechanism that relies solely on the system's latent representations (without the need of a separate model), VPR is able to dynamically adjust its internal state following changes in the observed features, promoting an optimal organisation of representations across the levels of the model's latent hierarchy. Using several video datasets, we show that VPR is able to detect event boundaries, disentangle spatiotemporal features across its hierarchy, adapt to the dynamics of the data, and produce accurate time-agnostic rollouts of the future. Our approach integrates insights from neuroscience and introduces a framework with high potential for applications in model-based reinforcement learning, where flexible and informative state-space rollouts are of particular interest.
Is High Variance Unavoidable in RL? A Case Study in Continuous Control
Bjorck, Johan, Gomes, Carla P., Weinberger, Kilian Q.
Reinforcement learning (RL) experiments have notoriously high variance, and minor details can have disproportionately large effects on measured outcomes. This is problematic for creating reproducible research and also serves as an obstacle for real-world applications, where safety and predictability are paramount. In this paper, we investigate causes for this perceived instability. To allow for an in-depth analysis, we focus on a specifically popular setup with high variance -- continuous control from pixels with an actor-critic agent. In this setting, we demonstrate that variance mostly arises early in training as a result of poor "outlier" runs, but that weight initialization and initial exploration are not to blame. We show that one cause for early variance is numerical instability which leads to saturating nonlinearities. We investigate several fixes to this issue and find that one particular method is surprisingly effective and simple -- normalizing penultimate features. Addressing the learning instability allows for larger learning rates, and significantly decreases the variance of outcomes. This demonstrates that the perceived variance in RL is not necessarily inherent to the problem definition and may be addressed through simple architectural modifications.
DAIR: Data Augmented Invariant Regularization
Huang, Tianjian, Halbe, Shaunak, Sankar, Chinnadhurai, Amini, Pooyan, Kottur, Satwik, Geramifard, Alborz, Razaviyayn, Meisam, Beirami, Ahmad
While deep learning through empirical risk minimization (ERM) has succeeded at achieving human-level performance at a variety of complex tasks, ERM generalizes poorly to distribution shift. This is partly explained by overfitting to spurious features such as background in images or named entities in natural language. Synthetic data augmentation followed by empirical risk minimization (DA-ERM) is a simple yet powerful solution to remedy this problem. In this paper, we propose data augmented invariant regularization (DAIR). The idea of DAIR is based on the observation that the model performance (loss) is desired to be consistent on the augmented sample and the original one. DAIR introduces a regularizer on DA-ERM to penalize such loss inconsistency. Both theoretically and through empirical experiments, we show that a particular form of the DAIR regularizer consistently performs well in a variety of settings. We apply it to multiple real-world learning problems involving domain shift, namely robust regression, visual question answering, robust deep neural network training, and task-oriented dialog modeling. Our experiments show that DAIR consistently outperforms ERM and DA-ERM with little marginal cost and setting new state-of-the-art results in several benchmarks.
Towards strong pruning for lottery tickets with non-zero biases
Fischer, Jonas, Burkholz, Rebekka
The strong lottery ticket hypothesis holds the promise that pruning randomly initialized deep neural networks could offer a computationally efficient alternative to deep learning with stochastic gradient descent. Common parameter initialization schemes and existence proofs, however, are focused on networks with zero biases, thus foregoing the potential universal approximation property of pruning. To fill this gap, we extend multiple initialization schemes and existence proofs to non-zero biases, including explicit'looks-linear' approaches for ReLU activation functions. These do not only enable truly orthogonal parameter initialization but also reduce potential pruning errors. In experiments on standard benchmark data sets, we further highlight the practical benefits of non-zero bias initialization schemes, and present theoretically inspired extensions for state-of-the-art strong lottery ticket pruning. Challenging tasks across different domains, from protein structure prediction for drug development to detection in complex scenes for self driving cars, have recently been solved through deep neural networks (NNs).
Mixer-based lidar lane detection network and dataset for urban roads
Paek, Donghee, Kong, Seung-Hyun, Wijaya, Kevin Tirta
Accurate lane detection under various road conditions is a critical function for autonomous driving. Generally, when detected lane lines from a front camera image are projected into a birds-eye view (BEV) for motion planning, the resulting lane lines are often distorted. And convolutional neural network (CNN)-based feature extractors often lose resolution when increasing the receptive field to detect global features such as lane lines. However, Lidar point cloud has little image distortion in the BEV-projection. Since lane lines are thin and stretch over entire BEV image while occupying only a small portion, lane lines should be detected as a global feature with high resolution. In this paper, we propose Lane Mixer Network (LMN) that extracts local features from Lidar point cloud, recognizes global features, and detects lane lines using a BEV encoder, a Mixer-based global feature extractor, and a detection head, respectively. In addition, we provide a world-first large urban lane dataset for Lidar, K-Lane, which has maximum 6 lanes under various urban road conditions. We demonstrate that the proposed LMN achieves the state-of-the-art performance, an F1 score of 91.67%, with K-Lane. The K-Lane, LMN training code, pre-trained models, and total dataset development platform are available at github.