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Rigorous State Evolution Analysis for Approximate Message Passing with Side Information
Liu, Hangjin, Rush, Cynthia, Baron, Dror
A common goal in many research areas is to reconstruct an unknown signal x from noisy linear measurements. Approximate message passing (AMP) is a class of low-complexity algorithms that can be used for efficiently solving such high-dimensional regression tasks. Often, it is the case that side information (SI) is available during reconstruction. For this reason, a novel algorithmic framework that incorporates SI into AMP, referred to as approximate message passing with side information (AMP-SI), has been recently introduced. In this work, we provide rigorous performance guarantees for AMP-SI when there are statistical dependencies between the signal and SI pairs and the entries of the measurement matrix are independent and identically distributed Gaussian. The AMP-SI performance is shown to be provably tracked by a scalar iteration referred to as state evolution. Moreover, we provide numerical examples that demonstrate empirically that the SE can predict the AMP-SI mean square error accurately.
Unsupervised domain adaptation with exploring more statistics and discriminative information
Du, Yuntao, Zhang, Ruiting, Cao, Yikang, Zhang, Xiaowen, Tan, Zhiwen, Wang, Chongjun
Unsupervised domain adaptation aims at transferring knowledge from the labeled source domain to the unlabeled target domain. Previous methods mainly learn a domain-invariant feature transformation, where the cross-domain discrepancy can be reduced. Maximum Mean Discrepancy(MMD) is the most popular statistic to measure domain discrepancy. However, these methods may suffer from two challenges. 1) MMD-based methods only measure the first-order statistic information across domains, while other useful information such as second-order statistic information has been ignored. 2) The classifier trained on the source domain may confuse to distinguish the correct class from a similar class, and the phenomenon is called class confusion. In this paper, we propose a method called \emph{Unsupervised domain adaptation with exploring more statistics and discriminative information}(MSDI), which tackle these two problems in the principle of structural risk minimization. We adopt the recently proposed statistic called MMCD to measure domain discrepancy which can capture both first-order and second-order statistics simultaneously in RKHS. Besides, we proposed to learn more discriminative features to avoid class confusion, where the inner of the classifier predictions with their transposes are used to reflect the confusion relationship between different classes. Moreover, we minimizing source empirical risk and adopt manifold regularization to explore geometry information in the target domain. MSDI learns a domain-invariant classifier in a unified learning framework incorporating the above objectives. We conduct comprehensive experiments on five real-world datasets and the results verify the effectiveness of the proposed method.
Bridging the Gap Between Spectral and Spatial Domains in Graph Neural Networks
Balcilar, Muhammet, Renton, Guillaume, Heroux, Pierre, Gauzere, Benoit, Adam, Sebastien, Honeine, Paul
This paper aims at revisiting Graph Convolutional Neural Networks by bridging the gap between spectral and spatial design of graph convolutions. We theoretically demonstrate some equivalence of the graph convolution process regardless it is designed in the spatial or the spectral domain. The obtained general framework allows to lead a spectral analysis of the most popular ConvGNNs, explaining their performance and showing their limits. Moreover, the proposed framework is used to design new convolutions in spectral domain with a custom frequency profile while applying them in the spatial domain. We also propose a generalization of the depthwise separable convolution framework for graph convolutional networks, what allows to decrease the total number of trainable parameters by keeping the capacity of the model. To the best of our knowledge, such a framework has never been used in the GNNs literature. Our proposals are evaluated on both transductive and inductive graph learning problems. Obtained results show the relevance of the proposed method and provide one of the first experimental evidence of transferability of spectral filter coefficients from one graph to another.
CAZSL: Zero-Shot Regression for Pushing Models by Generalizing Through Context
Zhang, Wenyu, Seto, Skyler, Jha, Devesh K.
Learning accurate models of the physical world is required for a lot of robotic manipulation tasks. However, during manipulation, robots are expected to interact with unknown workpieces so that building predictive models which can generalize over a number of these objects is highly desirable. In this paper, we study the problem of designing learning agents which can generalize their models of the physical world by building context-aware learning models. The purpose of these agents is to quickly adapt and/or generalize their notion of physics of interaction in the real world based on certain features about the interacting objects that provide different contexts to the predictive models. With this motivation, we present context-aware zero shot learning (CAZSL, pronounced as 'casual') models, an approach utilizing a Siamese network architecture, embedding space masking and regularization based on context variables which allows us to learn a model that can generalize to different parameters or features of the interacting objects. We test our proposed learning algorithm on the recently released Omnipush datatset that allows testing of meta-learning capabilities using low-dimensional data.
Common-Knowledge Concept Recognition for SEVA
Krishnan, Jitin, Coronado, Patrick, Purohit, Hemant, Rangwala, Huzefa
We build a common-knowledge concept recognition system for a Systems Engineer's Virtual Assistant (SEVA) which can be used for downstream tasks such as relation extraction, knowledge graph construction, and question-answering. The problem is formulated as a token classification task similar to named entity extraction. With the help of a domain expert and text processing methods, we construct a dataset annotated at the word-level by carefully defining a labelling scheme to train a sequence model to recognize systems engineering concepts. We use a pre-trained language model and fine-tune it with the labeled dataset of concepts. In addition, we also create some essential datasets for information such as abbreviations and definitions from the systems engineering domain. Finally, we construct a simple knowledge graph using these extracted concepts along with some hyponym relations.
Pipelined Backpropagation at Scale: Training Large Models without Batches
Kosson, Atli, Chiley, Vitaliy, Venigalla, Abhinav, Hestness, Joel, Köster, Urs
Parallelism is crucial for accelerating the training of deep neural networks. Pipeline parallelism can provide an efficient alternative to traditional data parallelism by allowing workers to specialize. Performing mini-batch SGD using pipeline parallelism has the overhead of filling and draining the pipeline. Pipelined Backpropagation updates the model parameters without draining the pipeline. This removes the overhead but introduces stale gradients and inconsistency between the weights used on the forward and backward passes, reducing final accuracy and the stability of training. We introduce Spike Compensation and Linear Weight Prediction to mitigate these effects. Analysis on a convex quadratic shows that both methods effectively counteract staleness. We train multiple convolutional networks at a batch size of one, completely replacing batch parallelism with fine-grained pipeline parallelism. With our methods, Pipelined Backpropagation achieves full accuracy on CIFAR-10 and ImageNet without hyperparameter tuning.
Deep Graph Matching via Blackbox Differentiation of Combinatorial Solvers
Rolínek, Michal, Swoboda, Paul, Zietlow, Dominik, Paulus, Anselm, Musil, Vít, Martius, Georg
Building on recent progress at the intersection of combinatorial optimization and deep learning, we propose an end-to-end trainable architecture for deep graph matching that contains unmodified combinatorial solvers. Using the presence of heavily optimized combinatorial solvers together with some improvements in architecture design, we advance state-of-the-art on deep graph matching benchmarks for keypoint correspondence. In addition, we highlight the conceptual advantages of incorporating solvers into deep learning architectures, such as the possibility of post-processing with a strong multi-graph matching solver or the indifference to changes in the training setting. Finally, we propose two new challenging experimental setups.
iTAML: An Incremental Task-Agnostic Meta-learning Approach
Rajasegaran, Jathushan, Khan, Salman, Hayat, Munawar, Khan, Fahad Shahbaz, Shah, Mubarak
Humans can continuously learn new knowledge as their experience grows. In contrast, previous learning in deep neural networks can quickly fade out when they are trained on a new task. In this paper, we hypothesize this problem can be avoided by learning a set of generalized parameters, that are neither specific to old nor new tasks. In this pursuit, we introduce a novel meta-learning approach that seeks to maintain an equilibrium between all the encountered tasks. This is ensured by a new meta-update rule which avoids catastrophic forgetting. In comparison to previous meta-learning techniques, our approach is task-agnostic. When presented with a continuum of data, our model automatically identifies the task and quickly adapts to it with just a single update. We perform extensive experiments on five datasets in a class-incremental setting, leading to significant improvements over the state of the art methods (e.g., a 21.3% boost on CIFAR100 with 10 incremental tasks). Specifically, on large-scale datasets that generally prove difficult cases for incremental learning, our approach delivers absolute gains as high as 19.1% and 7.4% on ImageNet and MS-Celeb datasets, respectively.
RelatIF: Identifying Explanatory Training Examples via Relative Influence
Barshan, Elnaz, Brunet, Marc-Etienne, Dziugaite, Gintare Karolina
In this work, we focus on the use of influence functions to identify relevant training examples that one might hope "explain" the predictions of a machine learning model. One shortcoming of influence functions is that the training examples deemed most "influential" are often outliers or mislabelled, making them poor choices for explanation. In order to address this shortcoming, we separate the role of global versus local influence. We introduce RelatIF, a new class of criteria for choosing relevant training examples by way of an optimization objective that places a constraint on global influence. RelatIF considers the local influence that an explanatory example has on a prediction relative to its global effects on the model. In empirical evaluations, we find that the examples returned by RelatIF are more intuitive when compared to those found using influence functions.
Heavy-tailed Representations, Text Polarity Classification & Data Augmentation
Jalalzai, Hamid, Colombo, Pierre, Clavel, Chloé, Gaussier, Eric, Varni, Giovanna, Vignon, Emmanuel, Sabourin, Anne
The dominant approaches to text representation in natural language rely on learning embeddings on massive corpora which have convenient properties such as compositionality and distance preservation. In this paper, we develop a novel method to learn a heavy-tailed embedding with desirable regularity properties regarding the distributional tails, which allows to analyze the points far away from the distribution bulk using the framework of multivariate extreme value theory. In particular, a classifier dedicated to the tails of the proposed embedding is obtained which performance outperforms the baseline. This classifier exhibits a scale invariance property which we leverage by introducing a novel text generation method for label preserving dataset augmentation. Numerical experiments on synthetic and real text data demonstrate the relevance of the proposed framework and confirm that this method generates meaningful sentences with controllable attribute, e.g.