January 25, 2020

3206 words 16 mins read

Paper Group NAWR 26

Paper Group NAWR 26

iComposer: An Automatic Songwriting System for Chinese Popular Music. Distributed Low-rank Matrix Factorization With Exact Consensus. XQA: A Cross-lingual Open-domain Question Answering Dataset. Rethinking Deep Neural Network Ownership Verification: Embedding Passports to Defeat Ambiguity Attacks. Ghmerti at SemEval-2019 Task 6: A Deep Word- and Ch …

Title iComposer: An Automatic Songwriting System for Chinese Popular Music
Authors Hsin-Pei Lee, Jhih-Sheng Fang, Wei-Yun Ma
Abstract In this paper, we introduce iComposer, an interactive web-based songwriting system designed to assist human creators by greatly simplifying music production. iComposer automatically creates melodies to accompany any given text. It also enables users to generate a set of lyrics given arbitrary melodies. iComposer is based on three sequence-to-sequence models, which are used to predict melody, rhythm, and lyrics, respectively. Songs generated by iComposer are compared with human-composed and randomly-generated ones in a subjective test, the experimental results of which demonstrate the capability of the proposed system to write pleasing melodies and meaningful lyrics at a level similar to that of humans.
Tasks
Published 2019-06-01
URL https://www.aclweb.org/anthology/N19-4015/
PDF https://www.aclweb.org/anthology/N19-4015
PWC https://paperswithcode.com/paper/icomposer-an-automatic-songwriting-system-for
Repo https://github.com/hhpslily/iComposer
Framework pytorch

Distributed Low-rank Matrix Factorization With Exact Consensus

Title Distributed Low-rank Matrix Factorization With Exact Consensus
Authors Zhihui Zhu, Qiuwei Li, Xinshuo Yang, Gongguo Tang, Michael B. Wakin
Abstract Low-rank matrix factorization is a problem of broad importance, owing to the ubiquity of low-rank models in machine learning contexts. In spite of its non- convexity, this problem has a well-behaved geometric landscape, permitting local search algorithms such as gradient descent to converge to global minimizers. In this paper, we study low-rank matrix factorization in the distributed setting, where local variables at each node encode parts of the overall matrix factors, and consensus is encouraged among certain such variables. We identify conditions under which this new problem also has a well-behaved geometric landscape, and we propose an extension of distributed gradient descent (DGD) to solve this problem. The favorable landscape allows us to prove convergence to global optimality with exact consensus, a stronger result than what is provided by off-the-shelf DGD theory.
Tasks
Published 2019-12-01
URL http://papers.nips.cc/paper/9050-distributed-low-rank-matrix-factorization-with-exact-consensus
PDF http://papers.nips.cc/paper/9050-distributed-low-rank-matrix-factorization-with-exact-consensus.pdf
PWC https://paperswithcode.com/paper/distributed-low-rank-matrix-factorization
Repo https://github.com/xinshuoyang/DGD-LOCAL
Framework none

XQA: A Cross-lingual Open-domain Question Answering Dataset

Title XQA: A Cross-lingual Open-domain Question Answering Dataset
Authors Jiahua Liu, Yankai Lin, Zhiyuan Liu, Maosong Sun
Abstract Open-domain question answering (OpenQA) aims to answer questions through text retrieval and reading comprehension. Recently, lots of neural network-based models have been proposed and achieved promising results in OpenQA. However, the success of these models relies on a massive volume of training data (usually in English), which is not available in many other languages, especially for those low-resource languages. Therefore, it is essential to investigate cross-lingual OpenQA. In this paper, we construct a novel dataset XQA for cross-lingual OpenQA research. It consists of a training set in English as well as development and test sets in eight other languages. Besides, we provide several baseline systems for cross-lingual OpenQA, including two machine translation-based methods and one zero-shot cross-lingual method (multilingual BERT). Experimental results show that the multilingual BERT model achieves the best results in almost all target languages, while the performance of cross-lingual OpenQA is still much lower than that of English. Our analysis indicates that the performance of cross-lingual OpenQA is related to not only how similar the target language and English are, but also how difficult the question set of the target language is. The XQA dataset is publicly available at http://github.com/thunlp/XQA.
Tasks Machine Translation, Open-Domain Question Answering, Question Answering, Reading Comprehension
Published 2019-07-01
URL https://www.aclweb.org/anthology/P19-1227/
PDF https://www.aclweb.org/anthology/P19-1227
PWC https://paperswithcode.com/paper/xqa-a-cross-lingual-open-domain-question
Repo https://github.com/thunlp/XQA
Framework tf

Rethinking Deep Neural Network Ownership Verification: Embedding Passports to Defeat Ambiguity Attacks

Title Rethinking Deep Neural Network Ownership Verification: Embedding Passports to Defeat Ambiguity Attacks
Authors Lixin Fan, Kam Woh Ng, Chee Seng Chan
Abstract With substantial amount of time, resources and human (team) efforts invested to explore and develop successful deep neural networks (DNN), there emerges an urgent need to protect these inventions from being illegally copied, redistributed, or abused without respecting the intellectual properties of legitimate owners. Following recent progresses along this line, we investigate a number of watermark-based DNN ownership verification methods in the face of ambiguity attacks, which aim to cast doubts on the ownership verification by forging counterfeit watermarks. It is shown that ambiguity attacks pose serious threats to existing DNN watermarking methods. As remedies to the above-mentioned loophole, this paper proposes novel passport-based DNN ownership verification schemes which are both robust to network modifications and resilient to ambiguity attacks. The gist of embedding digital passports is to design and train DNN models in a way such that, the DNN inference performance of an original task will be significantly deteriorated due to forged passports. In other words, genuine passports are not only verified by looking for the predefined signatures, but also reasserted by the unyielding DNN model inference performances. Extensive experimental results justify the effectiveness of the proposed passport-based DNN ownership verification schemes. Code and models are available at https://github.com/kamwoh/DeepIPR
Tasks
Published 2019-12-01
URL http://papers.nips.cc/paper/8719-rethinking-deep-neural-network-ownership-verification-embedding-passports-to-defeat-ambiguity-attacks
PDF http://papers.nips.cc/paper/8719-rethinking-deep-neural-network-ownership-verification-embedding-passports-to-defeat-ambiguity-attacks.pdf
PWC https://paperswithcode.com/paper/rethinking-deep-neural-network-ownership-1
Repo https://github.com/kamwoh/DeepIPR
Framework pytorch

Ghmerti at SemEval-2019 Task 6: A Deep Word- and Character-based Approach to Offensive Language Identification

Title Ghmerti at SemEval-2019 Task 6: A Deep Word- and Character-based Approach to Offensive Language Identification
Authors Ehsan Doostmohammadi, Hossein Sameti, Ali Saffar
Abstract This paper presents the models submitted by Ghmerti team for subtasks A and B of the OffensEval shared task at SemEval 2019. OffensEval addresses the problem of identifying and categorizing offensive language in social media in three subtasks; whether or not a content is offensive (subtask A), whether it is targeted (subtask B) towards an individual, a group, or other entities (subtask C). The proposed approach includes character-level Convolutional Neural Network, word-level Recurrent Neural Network, and some preprocessing. The performance achieved by the proposed model is 77.93{%} macro-averaged F1-score.
Tasks Language Identification
Published 2019-06-01
URL https://www.aclweb.org/anthology/S19-2110/
PDF https://www.aclweb.org/anthology/S19-2110
PWC https://paperswithcode.com/paper/ghmerti-at-semeval-2019-task-6-a-deep-word
Repo https://github.com/edoost/offenseval
Framework tf

Latent Ordinary Differential Equations for Irregularly-Sampled Time Series

Title Latent Ordinary Differential Equations for Irregularly-Sampled Time Series
Authors Yulia Rubanova, Tian Qi Chen, David K. Duvenaud
Abstract Time series with non-uniform intervals occur in many applications, and are difficult to model using standard recurrent neural networks (RNNs). We generalize RNNs to have continuous-time hidden dynamics defined by ordinary differential equations (ODEs), a model we call ODE-RNNs. Furthermore, we use ODE-RNNs to replace the recognition network of the recently-proposed Latent ODE model. Both ODE-RNNs and Latent ODEs can naturally handle arbitrary time gaps between observations, and can explicitly model the probability of observation times using Poisson processes. We show experimentally that these ODE-based models outperform their RNN-based counterparts on irregularly-sampled data.
Tasks Time Series
Published 2019-12-01
URL http://papers.nips.cc/paper/8773-latent-ordinary-differential-equations-for-irregularly-sampled-time-series
PDF http://papers.nips.cc/paper/8773-latent-ordinary-differential-equations-for-irregularly-sampled-time-series.pdf
PWC https://paperswithcode.com/paper/latent-ordinary-differential-equations-for
Repo https://github.com/YuliaRubanova/latent_ode
Framework pytorch

DC2Anet: Generating Lumbar Spine MR Images from CT Scan Data Based on Semi-Supervised Learning

Title DC2Anet: Generating Lumbar Spine MR Images from CT Scan Data Based on Semi-Supervised Learning
Authors Cheng-Bin Jin, Hakil Kim, Mingjie Liu, In Ho Han, Jae Il Lee, Jung Hwan Lee, Seongsu Joo, Eunsik Park, Young Saem Ahn, Xuenan Cui
Abstract Magnetic resonance imaging (MRI) plays a significant role in the diagnosis of lumbar disc disease. However, the use of MRI is limited because of its high cost and significant operating and processing time. More importantly, MRI is contraindicated for some patients with claustrophobia or cardiac pacemakers due to the possibility of injury. In contrast, computed tomography (CT) scans are much less expensive, are faster, and do not face the same limitations. In this paper, we propose a method for estimating lumbar spine MR images based on CT images using a novel objective function and a dual cycle-consistent adversarial network (DC2Anet) with semi-supervised learning. The objective function includes six independent loss terms to balance quantitative and qualitative losses, enabling the generation of a realistic and accurate synthetic MR image. DC2Anet is also capable of semi-supervised learning, and the network is general enough for supervised or unsupervised setups. Experimental results prove that the method is accurate, being able to construct MR images that closely approximate reference MR images, while also outperforming four other state-of-the-art methods.
Tasks Computed Tomography (CT)
Published 2019-06-18
URL https://www.mdpi.com/2076-3417/9/12/2521
PDF https://www.mdpi.com/2076-3417/9/12/2521
PWC https://paperswithcode.com/paper/dc2anet-generating-lumbar-spine-mr-images
Repo https://github.com/ChengBinJin/SpineC2M
Framework tf

Acoustic Non-Line-Of-Sight Imaging

Title Acoustic Non-Line-Of-Sight Imaging
Authors David B. Lindell, Gordon Wetzstein, Vladlen Koltun
Abstract Non-line-of-sight (NLOS) imaging enables unprecedented capabilities in a wide range of applications, including robotic and machine vision, remote sensing, autonomous vehicle navigation, and medical imaging. Recent approaches to solving this challenging problem employ optical time-of-flight imaging systems with highly sensitive time-resolved photodetectors and ultra-fast pulsed lasers. However, despite recent successes in NLOS imaging using these systems, widespread implementation and adoption of the technology remains a challenge because of the requirement for specialized, expensive hardware. We introduce acoustic NLOS imaging, which is orders of magnitude less expensive than most optical systems and captures hidden 3D geometry at longer ranges with shorter acquisition times compared to state-of-the-art optical methods. Inspired by hardware setups used in radar and algorithmic approaches to model and invert wave-based image formation models developed in the seismic imaging community, we demonstrate a new approach to seeing around corners.
Tasks
Published 2019-06-01
URL http://openaccess.thecvf.com/content_CVPR_2019/html/Lindell_Acoustic_Non-Line-Of-Sight_Imaging_CVPR_2019_paper.html
PDF http://openaccess.thecvf.com/content_CVPR_2019/papers/Lindell_Acoustic_Non-Line-Of-Sight_Imaging_CVPR_2019_paper.pdf
PWC https://paperswithcode.com/paper/acoustic-non-line-of-sight-imaging
Repo https://github.com/computational-imaging/AcousticNLOS
Framework none

On two ways to use determinantal point processes for Monte Carlo integration

Title On two ways to use determinantal point processes for Monte Carlo integration
Authors Guillaume Gautier, Rémi Bardenet, Michal Valko
Abstract When approximating an integral by a weighted sum of function evaluations, determinantal point processes (DPPs) provide a way to enforce repulsion between the evaluation points. This negative dependence is encoded by a kernel. Fifteen years before the discovery of DPPs, Ermakov & Zolotukhin (EZ, 1960) had the intuition of sampling a DPP and solving a linear system to compute an unbiased Monte Carlo estimator of the integral. In the absence of DPP machinery to derive an efficient sampler and analyze their estimator, the idea of Monte Carlo integration with DPPs was stored in the cellar of numerical integration. Recently, Bardenet & Hardy (BH, 2019) came up with a more natural estimator with a fast central limit theorem (CLT). In this paper, we first take the EZ estimator out of the cellar, and analyze it using modern arguments. Second, we provide an efficient implementation to sample exactly a particular multidimensional DPP called multivariate Jacobi ensemble. The latter satisfies the assumptions of the aforementioned CLT. Third, our new implementation lets us investigate the behavior of the two unbiased Monte Carlo estimators in yet unexplored regimes. We demonstrate experimentally good properties when the kernel is adapted to basis of functions in which the integrand is sparse or has fast-decaying coefficients. If such a basis and the level of sparsity are known (e.g., we integrate a linear combination of kernel eigenfunctions), the EZ estimator can be the right choice, but otherwise it can display an erratic behavior.
Tasks Point Processes
Published 2019-12-01
URL http://papers.nips.cc/paper/8992-on-two-ways-to-use-determinantal-point-processes-for-monte-carlo-integration
PDF http://papers.nips.cc/paper/8992-on-two-ways-to-use-determinantal-point-processes-for-monte-carlo-integration.pdf
PWC https://paperswithcode.com/paper/on-two-ways-to-use-determinantal-point
Repo https://github.com/guilgautier/DPPy
Framework none

Random Path Selection for Continual Learning

Title Random Path Selection for Continual Learning
Authors Jathushan Rajasegaran, Munawar Hayat, Salman H. Khan, Fahad Shahbaz Khan, Ling Shao
Abstract Incremental life-long learning is a main challenge towards the long-standing goal of Artificial General Intelligence. In real-life settings, learning tasks arrive in a sequence and machine learning models must continually learn to increment already acquired knowledge. The existing incremental learning approaches fall well below the state-of-the-art cumulative models that use all training classes at once. In this paper, we propose a random path selection algorithm, called RPS-Net, that progressively chooses optimal paths for the new tasks while encouraging parameter sharing and reuse. Our approach avoids the overhead introduced by computationally expensive evolutionary and reinforcement learning based path selection strategies while achieving considerable performance gains. As an added novelty, the proposed model integrates knowledge distillation and retrospection along with the path selection strategy to overcome catastrophic forgetting. In order to maintain an equilibrium between previous and newly acquired knowledge, we propose a simple controller to dynamically balance the model plasticity. Through extensive experiments, we demonstrate that the proposed method surpasses the state-of-the-art performance on incremental learning and by utilizing parallel computation this method can run in constant time with nearly the same efficiency as a conventional deep convolutional neural network.
Tasks Continual Learning
Published 2019-12-01
URL http://papers.nips.cc/paper/9429-random-path-selection-for-continual-learning
PDF http://papers.nips.cc/paper/9429-random-path-selection-for-continual-learning.pdf
PWC https://paperswithcode.com/paper/random-path-selection-for-continual-learning
Repo https://github.com/brjathu/RPSnet
Framework pytorch

Pay Attention! - Robustifying a Deep Visuomotor Policy Through Task-Focused Visual Attention

Title Pay Attention! - Robustifying a Deep Visuomotor Policy Through Task-Focused Visual Attention
Authors Pooya Abolghasemi, Amir Mazaheri, Mubarak Shah, Ladislau Boloni
Abstract Several recent studies have demonstrated the promise of deep visuomotor policies for robot manipulator control. Despite impressive progress, these systems are known to be vulnerable to physical disturbances, such as accidental or adversarial bumps that make them drop the manipulated object. They also tend to be distracted by visual disturbances such as objects moving in the robot’s field of view, even if the disturbance does not physically prevent the execution of the task. In this paper, we propose an approach for augmenting a deep visuomotor policy trained through demonstrations with Task Focused visual Attention (TFA). The manipulation task is specified with a natural language text such as “move the red bowl to the left”. This allows the visual attention component to concentrate on the current object that the robot needs to manipulate. We show that even in benign environments, the TFA allows the policy to consistently outperform a variant with no attention mechanism. More importantly, the new policy is significantly more robust: it regularly recovers from severe physical disturbances (such as bumps causing it to drop the object) from which the baseline policy, i.e. with no visual attention, almost never recovers. In addition, we show that the proposed policy performs correctly in the presence of a wide class of visual disturbances, exhibiting a behavior reminiscent of human selective visual attention experiments.
Tasks Imitation Learning
Published 2019-06-01
URL http://openaccess.thecvf.com/content_CVPR_2019/html/Abolghasemi_Pay_Attention_-_Robustifying_a_Deep_Visuomotor_Policy_Through_Task-Focused_CVPR_2019_paper.html
PDF http://openaccess.thecvf.com/content_CVPR_2019/papers/Abolghasemi_Pay_Attention_-_Robustifying_a_Deep_Visuomotor_Policy_Through_Task-Focused_CVPR_2019_paper.pdf
PWC https://paperswithcode.com/paper/pay-attention-robustifying-a-deep-visuomotor-1
Repo https://github.com/pouyaAB/Pay-Attention
Framework none

UnOS: Unified Unsupervised Optical-Flow and Stereo-Depth Estimation by Watching Videos

Title UnOS: Unified Unsupervised Optical-Flow and Stereo-Depth Estimation by Watching Videos
Authors Yang Wang, Peng Wang, Zhenheng Yang, Chenxu Luo, Yi Yang, Wei Xu
Abstract In this paper, we propose UnOS, an unified system for unsupervised optical flow and stereo depth estimation using convolutional neural network (CNN) by taking advantages of their inherent geometrical consistency based on the rigid-scene assumption. UnOS significantly outperforms other state-of-the-art (SOTA) unsupervised approaches that treated the two tasks independently. Specifically, given two consecutive stereo image pairs from a video, UnOS estimates per-pixel stereo depth images, camera ego-motion and optical flow with three parallel CNNs. Based on these quantities, UnOS computes rigid optical flow and compares it against the optical flow estimated from the FlowNet, yielding pixels satisfying the rigid-scene assumption. Then, we encourage geometrical consistency between the two estimated flows within rigid regions, from which we derive a rigid-aware direct visual odometry (RDVO) module. We also propose rigid and occlusion-aware flow-consistency losses for the learning of UnOS. We evaluated our results on the popular KITTI dataset over 4 related tasks, i.e. stereo depth, optical flow, visual odometry and motion segmentation.
Tasks Depth Estimation, Motion Segmentation, Optical Flow Estimation, Stereo Depth Estimation, Visual Odometry
Published 2019-06-01
URL http://openaccess.thecvf.com/content_CVPR_2019/html/Wang_UnOS_Unified_Unsupervised_Optical-Flow_and_Stereo-Depth_Estimation_by_Watching_Videos_CVPR_2019_paper.html
PDF http://openaccess.thecvf.com/content_CVPR_2019/papers/Wang_UnOS_Unified_Unsupervised_Optical-Flow_and_Stereo-Depth_Estimation_by_Watching_Videos_CVPR_2019_paper.pdf
PWC https://paperswithcode.com/paper/unos-unified-unsupervised-optical-flow-and
Repo https://github.com/baidu-research/UnDepthflow
Framework tf

Rethinking Complex Neural Network Architectures for Document Classification

Title Rethinking Complex Neural Network Architectures for Document Classification
Authors Ashutosh Adhikari, Achyudh Ram, Raphael Tang, Jimmy Lin
Abstract Neural network models for many NLP tasks have grown increasingly complex in recent years, making training and deployment more difficult. A number of recent papers have questioned the necessity of such architectures and found that well-executed, simpler models are quite effective. We show that this is also the case for document classification: in a large-scale reproducibility study of several recent neural models, we find that a simple BiLSTM architecture with appropriate regularization yields accuracy and F1 that are either competitive or exceed the state of the art on four standard benchmark datasets. Surprisingly, our simple model is able to achieve these results without attention mechanisms. While these regularization techniques, borrowed from language modeling, are not novel, to our knowledge we are the first to apply them in this context. Our work provides an open-source platform and the foundation for future work in document classification.
Tasks Document Classification, Language Modelling
Published 2019-06-01
URL https://www.aclweb.org/anthology/N19-1408/
PDF https://www.aclweb.org/anthology/N19-1408
PWC https://paperswithcode.com/paper/rethinking-complex-neural-network
Repo https://github.com/castorini/hedwig
Framework pytorch

Speak up, Fight Back! Detection of Social Media Disclosures of Sexual Harassment

Title Speak up, Fight Back! Detection of Social Media Disclosures of Sexual Harassment
Authors Arijit Ghosh Chowdhury, Ramit Sawhney, Puneet Mathur, Debanjan Mahata, Rajiv Ratn Shah
Abstract The {#}MeToo movement is an ongoing prevalent phenomenon on social media aiming to demonstrate the frequency and widespread of sexual harassment by providing a platform to speak narrate personal experiences of such harassment. The aggregation and analysis of such disclosures pave the way to development of technology-based prevention of sexual harassment. We contend that the lack of specificity in generic sentence classification models may not be the best way to tackle text subtleties that intrinsically prevail in a classification task as complex as identifying disclosures of sexual harassment. We propose the Disclosure Language Model, a three part ULMFiT architecture, consisting of a Language model, a Medium-Specific (Twitter) model and a Task-Specific classifier to tackle this problem and create a manually annotated real-world dataset to test our technique on this, to show that using a Discourse Language Model often yields better classification performance over (i) Generic deep learning based sentence classification models (ii) existing models that rely on handcrafted stylistic features. An extensive comparison with state-of-the-art generic and specific models along with a detailed error analysis presents the case for our proposed methodology.
Tasks Language Modelling, Sentence Classification
Published 2019-06-01
URL https://www.aclweb.org/anthology/N19-3018/
PDF https://www.aclweb.org/anthology/N19-3018
PWC https://paperswithcode.com/paper/speak-up-fight-back-detection-of-social-media
Repo https://github.com/ramitsawhney27/NAACLSRW19meToo
Framework none

Offline Contextual Bayesian Optimization

Title Offline Contextual Bayesian Optimization
Authors Ian Char, Youngseog Chung, Willie Neiswanger, Kirthevasan Kandasamy, Oak Nelson, Mark Boyer, Egemen Kolemen
Abstract In black-box optimization, an agent repeatedly chooses a configuration to test, so as to find an optimal configuration. In many practical problems of interest, one would like to optimize several systems, or tasks'', simultaneously; however, in most of these scenarios the current task is determined by nature. In this work, we explore the offline’’ case in which one is able to bypass nature and choose the next task to evaluate (e.g. via a simulator). Because some tasks may be easier to optimize and others may be more critical, it is crucial to leverage algorithms that not only consider which configurations to try next, but also which tasks to make evaluations for. In this work, we describe a theoretically grounded Bayesian optimization method to tackle this problem. We also demonstrate that if the model of the reward structure does a poor job of capturing variation in difficulty between tasks, then algorithms that actively pick tasks for evaluation may end up doing more harm than good. Following this, we show how our approach can be used for real world applications in science and engineering, including optimizing tokamak controls for nuclear fusion.
Tasks
Published 2019-12-01
URL http://papers.nips.cc/paper/8711-offline-contextual-bayesian-optimization
PDF http://papers.nips.cc/paper/8711-offline-contextual-bayesian-optimization.pdf
PWC https://paperswithcode.com/paper/offline-contextual-bayesian-optimization
Repo https://github.com/fusion-ml/OCBO
Framework none
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