January 25, 2020

2515 words 12 mins read

Paper Group NANR 37

Paper Group NANR 37

Reflective and Fluorescent Separation Under Narrow-Band Illumination. The Fallacy of Echo Chambers: Analyzing the Political Slants of User-Generated News Comments in Korean Media. Max-value Entropy Search for Multi-Objective Bayesian Optimization. Additive Compositionality of Word Vectors. Aligning Latent Spaces for 3D Hand Pose Estimation. SO-Hand …

Reflective and Fluorescent Separation Under Narrow-Band Illumination

Title Reflective and Fluorescent Separation Under Narrow-Band Illumination
Authors Koji Koyamatsu, Daichi Hidaka, Takahiro Okabe, Hendrik P. A. Lensch
Abstract In this paper, we address the separation of reflective and fluorescent components in RGB images taken under narrow-band light sources such as LEDs. First, we show that the fluorescent color per pixel can be estimated from at least two images under different light source colors, because the observed color at a surface point is represented by a convex combination of the light source color and the illumination-invariant fluorescent color. Second, we propose a method for robustly estimating the fluorescent color via MAP estimation by taking the prior knowledge with respect to fluorescent colors into consideration. We conducted a number of experiments by using both synthetic and real images, and confirmed that our proposed method works better than the closely related state-of-the-art method and enables us to separate reflective and fluorescent components even from a single image. Furthermore, we demonstrate that our method is effective for applications such as image-based material editing and relighting.
Tasks
Published 2019-06-01
URL http://openaccess.thecvf.com/content_CVPR_2019/html/Koyamatsu_Reflective_and_Fluorescent_Separation_Under_Narrow-Band_Illumination_CVPR_2019_paper.html
PDF http://openaccess.thecvf.com/content_CVPR_2019/papers/Koyamatsu_Reflective_and_Fluorescent_Separation_Under_Narrow-Band_Illumination_CVPR_2019_paper.pdf
PWC https://paperswithcode.com/paper/reflective-and-fluorescent-separation-under
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The Fallacy of Echo Chambers: Analyzing the Political Slants of User-Generated News Comments in Korean Media

Title The Fallacy of Echo Chambers: Analyzing the Political Slants of User-Generated News Comments in Korean Media
Authors Jiyoung Han, Youngin Lee, Junbum Lee, Meeyoung Cha
Abstract This study analyzes the political slants of user comments on Korean partisan media. We built a BERT-based classifier to detect political leaning of short comments via the use of semi-unsupervised deep learning methods that produced an F1 score of 0.83. As a result of classifying 21.6K comments, we found the high presence of conservative bias on both conservative and liberal news outlets. Moreover, this study discloses an asymmetry across the partisan spectrum in that more liberals (48.0{%}) than conservatives (23.6{%}) comment not only on news stories resonating with their political perspectives but also on those challenging their viewpoints. These findings advance the current understanding of online echo chambers.
Tasks
Published 2019-11-01
URL https://www.aclweb.org/anthology/D19-5548/
PDF https://www.aclweb.org/anthology/D19-5548
PWC https://paperswithcode.com/paper/the-fallacy-of-echo-chambers-analyzing-the
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Max-value Entropy Search for Multi-Objective Bayesian Optimization

Title Max-value Entropy Search for Multi-Objective Bayesian Optimization
Authors Syrine Belakaria, Aryan Deshwal, Janardhan Rao Doppa
Abstract We consider the problem of multi-objective (MO) blackbox optimization using expensive function evaluations, where the goal is to approximate the true Pareto-set of solutions by minimizing the number of function evaluations. For example, in hardware design optimization, we need to find the designs that trade-off performance, energy, and area overhead using expensive simulations. We propose a novel approach referred to as Max-value Entropy Search for Multi-objective Optimization (MESMO) to solve this problem. MESMO employs an output-space entropy based acquisition function to efficiently select the sequence of inputs for evaluation for quickly uncovering high-quality solutions. We also provide theoretical analysis to characterize the efficacy of MESMO. Our experiments on several synthetic and real-world benchmark problems show that MESMO consistently outperforms state-of-the-art algorithms.
Tasks
Published 2019-12-01
URL http://papers.nips.cc/paper/8997-max-value-entropy-search-for-multi-objective-bayesian-optimization
PDF http://papers.nips.cc/paper/8997-max-value-entropy-search-for-multi-objective-bayesian-optimization.pdf
PWC https://paperswithcode.com/paper/max-value-entropy-search-for-multi-objective
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Additive Compositionality of Word Vectors

Title Additive Compositionality of Word Vectors
Authors Yeon Seonwoo, Sungjoon Park, Dongkwan Kim, Alice Oh
Abstract Additive compositionality of word embedding models has been studied from empirical and theoretical perspectives. Existing research on justifying additive compositionality of existing word embedding models requires a rather strong assumption of uniform word distribution. In this paper, we relax that assumption and propose more realistic conditions for proving additive compositionality, and we develop a novel word and sub-word embedding model that satisfies additive compositionality under those conditions. We then empirically show our model{'}s improved semantic representation performance on word similarity and noisy sentence similarity.
Tasks
Published 2019-11-01
URL https://www.aclweb.org/anthology/D19-5551/
PDF https://www.aclweb.org/anthology/D19-5551
PWC https://paperswithcode.com/paper/additive-compositionality-of-word-vectors
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Aligning Latent Spaces for 3D Hand Pose Estimation

Title Aligning Latent Spaces for 3D Hand Pose Estimation
Authors Linlin Yang, Shile Li, Dongheui Lee, Angela Yao
Abstract Hand pose estimation from monocular RGB inputs is a highly challenging task. Many previous works for monocular settings only used RGB information for training despite the availability of corresponding data in other modalities such as depth maps. In this work, we propose to learn a joint latent representation that leverages other modalities as weak labels to boost the RGB-based hand pose estimator. By design, our architecture is highly flexible in embedding various diverse modalities such as heat maps, depth maps and point clouds. In particular, we find that encoding and decoding the point cloud of the hand surface can improve the quality of the joint latent representation. Experiments show that with the aid of other modalities during training, our proposed method boosts the accuracy of RGB-based hand pose estimation systems and significantly outperforms state-of-the-art on two public benchmarks.
Tasks Hand Pose Estimation, Pose Estimation
Published 2019-10-01
URL http://openaccess.thecvf.com/content_ICCV_2019/html/Yang_Aligning_Latent_Spaces_for_3D_Hand_Pose_Estimation_ICCV_2019_paper.html
PDF http://openaccess.thecvf.com/content_ICCV_2019/papers/Yang_Aligning_Latent_Spaces_for_3D_Hand_Pose_Estimation_ICCV_2019_paper.pdf
PWC https://paperswithcode.com/paper/aligning-latent-spaces-for-3d-hand-pose
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SO-HandNet: Self-Organizing Network for 3D Hand Pose Estimation With Semi-Supervised Learning

Title SO-HandNet: Self-Organizing Network for 3D Hand Pose Estimation With Semi-Supervised Learning
Authors Yujin Chen, Zhigang Tu, Liuhao Ge, Dejun Zhang, Ruizhi Chen, Junsong Yuan
Abstract 3D hand pose estimation has made significant progress recently, where Convolutional Neural Networks (CNNs) play a critical role. However, most of the existing CNN-based hand pose estimation methods depend much on the training set, while labeling 3D hand pose on training data is laborious and time-consuming. Inspired by the point cloud autoencoder presented in self-organizing network (SO-Net), our proposed SO-HandNet aims at making use of the unannotated data to obtain accurate 3D hand pose estimation in a semi-supervised manner. We exploit hand feature encoder (HFE) to extract multi-level features from hand point cloud and then fuse them to regress 3D hand pose by a hand pose estimator (HPE). We design a hand feature decoder (HFD) to recover the input point cloud from the encoded feature. Since the HFE and the HFD can be trained without 3D hand pose annotation, the proposed method is able to make the best of unannotated data during the training phase. Experiments on four challenging benchmark datasets validate that our proposed SO-HandNet can achieve superior performance for 3D hand pose estimation via semi-supervised learning.
Tasks Hand Pose Estimation, Pose Estimation
Published 2019-10-01
URL http://openaccess.thecvf.com/content_ICCV_2019/html/Chen_SO-HandNet_Self-Organizing_Network_for_3D_Hand_Pose_Estimation_With_Semi-Supervised_ICCV_2019_paper.html
PDF http://openaccess.thecvf.com/content_ICCV_2019/papers/Chen_SO-HandNet_Self-Organizing_Network_for_3D_Hand_Pose_Estimation_With_Semi-Supervised_ICCV_2019_paper.pdf
PWC https://paperswithcode.com/paper/so-handnet-self-organizing-network-for-3d
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Learning to Minify Photometric Stereo

Title Learning to Minify Photometric Stereo
Authors Junxuan Li, Antonio Robles-Kelly, Shaodi You, Yasuyuki Matsushita
Abstract Photometric stereo estimates the surface normal given a set of images acquired under different illumination conditions. To deal with diverse factors involved in the image formation process, recent photometric stereo methods demand a large number of images as input. We propose a method that can dramatically decrease the demands on the number of images by learning the most informative ones under different illumination conditions. To this end, we use a deep learning framework to automatically learn the critical illumination conditions required at input. Furthermore, we present an occlusion layer that can synthesize cast shadows, which effectively improves the estimation accuracy. We assess our method on challenging real-world conditions, where we outperform techniques elsewhere in the literature with a significantly reduced number of light conditions.
Tasks
Published 2019-06-01
URL http://openaccess.thecvf.com/content_CVPR_2019/html/Li_Learning_to_Minify_Photometric_Stereo_CVPR_2019_paper.html
PDF http://openaccess.thecvf.com/content_CVPR_2019/papers/Li_Learning_to_Minify_Photometric_Stereo_CVPR_2019_paper.pdf
PWC https://paperswithcode.com/paper/learning-to-minify-photometric-stereo
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Provably Global Convergence of Actor-Critic: A Case for Linear Quadratic Regulator with Ergodic Cost

Title Provably Global Convergence of Actor-Critic: A Case for Linear Quadratic Regulator with Ergodic Cost
Authors Zhuoran Yang, Yongxin Chen, Mingyi Hong, Zhaoran Wang
Abstract Despite the empirical success of the actor-critic algorithm, its theoretical understanding lags behind. In a broader context, actor-critic can be viewed as an online alternating update algorithm for bilevel optimization, whose convergence is known to be fragile. To understand the instability of actor-critic, we focus on its application to linear quadratic regulators, a simple yet fundamental setting of reinforcement learning. We establish a nonasymptotic convergence analysis of actor- critic in this setting. In particular, we prove that actor-critic finds a globally optimal pair of actor (policy) and critic (action-value function) at a linear rate of convergence. Our analysis may serve as a preliminary step towards a complete theoretical understanding of bilevel optimization with nonconvex subproblems, which is NP-hard in the worst case and is often solved using heuristics.
Tasks bilevel optimization
Published 2019-12-01
URL http://papers.nips.cc/paper/9044-provably-global-convergence-of-actor-critic-a-case-for-linear-quadratic-regulator-with-ergodic-cost
PDF http://papers.nips.cc/paper/9044-provably-global-convergence-of-actor-critic-a-case-for-linear-quadratic-regulator-with-ergodic-cost.pdf
PWC https://paperswithcode.com/paper/provably-global-convergence-of-actor-critic-a
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Neural Dependency Parsing of Biomedical Text: TurkuNLP entry in the CRAFT Structural Annotation Task

Title Neural Dependency Parsing of Biomedical Text: TurkuNLP entry in the CRAFT Structural Annotation Task
Authors Thang Minh Ngo, Jenna Kanerva, Filip Ginter, Sampo Pyysalo
Abstract We present the approach taken by the TurkuNLP group in the CRAFT Structural Annotation task, a shared task on dependency parsing. Our approach builds primarily on the Turku neural parser, a native dependency parser that ranked among the best in the recent CoNLL tasks on parsing Universal Dependencies. To adapt the parser to the biomedical domain, we considered and evaluated a number of approaches, including the generation of custom word embeddings, combination with other in-domain resources, and the incorporation of information from named entity recognition. We achieved a labeled attachment score of 89.7{%}, the best result among task participants.
Tasks Dependency Parsing, Named Entity Recognition, Word Embeddings
Published 2019-11-01
URL https://www.aclweb.org/anthology/D19-5728/
PDF https://www.aclweb.org/anthology/D19-5728
PWC https://paperswithcode.com/paper/neural-dependency-parsing-of-biomedical-text
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Duluth at SemEval-2019 Task 6: Lexical Approaches to Identify and Categorize Offensive Tweets

Title Duluth at SemEval-2019 Task 6: Lexical Approaches to Identify and Categorize Offensive Tweets
Authors Ted Pedersen
Abstract This paper describes the Duluth systems that participated in SemEval{–}2019 Task 6, Identifying and Categorizing Offensive Language in Social Media (OffensEval). For the most part these systems took traditional Machine Learning approaches that built classifiers from lexical features found in manually labeled training data. However, our most successful system for classifying a tweet as offensive (or not) was a rule-based black{–}list approach, and we also experimented with combining the training data from two different but related SemEval tasks. Our best systems in each of the three OffensEval tasks placed in the middle of the comparative evaluation, ranking 57th of 103 in task A, 39th of 75 in task B, and 44th of 65 in task C.
Tasks
Published 2019-06-01
URL https://www.aclweb.org/anthology/S19-2106/
PDF https://www.aclweb.org/anthology/S19-2106
PWC https://paperswithcode.com/paper/duluth-at-semeval-2019-task-6-lexical
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Title Transfer Learning for Health-related Twitter Data
Authors Anne Dirkson, Suzan Verberne
Abstract Transfer learning is promising for many NLP applications, especially in tasks with limited labeled data. This paper describes the methods developed by team TMRLeiden for the 2019 Social Media Mining for Health Applications (SMM4H) Shared Task. Our methods use state-of-the-art transfer learning methods to classify, extract and normalise adverse drug effects (ADRs) and to classify personal health mentions from health-related tweets. The code and fine-tuned models are publicly available.
Tasks Transfer Learning
Published 2019-08-01
URL https://www.aclweb.org/anthology/W19-3212/
PDF https://www.aclweb.org/anthology/W19-3212
PWC https://paperswithcode.com/paper/transfer-learning-for-health-related-twitter
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NLP@UNED at SMM4H 2019: Neural Networks Applied to Automatic Classifications of Adverse Effects Mentions in Tweets

Title NLP@UNED at SMM4H 2019: Neural Networks Applied to Automatic Classifications of Adverse Effects Mentions in Tweets
Authors Javier Cortes-Tejada, Juan Martinez-Romo, Lourdes Araujo
Abstract This paper describes a system for automatically classifying adverse effects mentions in tweets developed for the task 1 at Social Media Mining for Health Applications (SMM4H) Shared Task 2019. We have developed a system based on LSTM neural networks inspired by the excellent results obtained by deep learning classifiers in the last edition of this task. The network is trained along with Twitter GloVe pre-trained word embeddings.
Tasks Word Embeddings
Published 2019-08-01
URL https://www.aclweb.org/anthology/W19-3213/
PDF https://www.aclweb.org/anthology/W19-3213
PWC https://paperswithcode.com/paper/nlpuned-at-smm4h-2019-neural-networks-applied
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LaSTUS/TALN at SemEval-2019 Task 6: Identification and Categorization of Offensive Language in Social Media with Attention-based Bi-LSTM model

Title LaSTUS/TALN at SemEval-2019 Task 6: Identification and Categorization of Offensive Language in Social Media with Attention-based Bi-LSTM model
Authors Lutfiye Seda Mut Altin, {`A}lex Bravo Serrano, Horacio Saggion
Abstract We present a bidirectional Long-Short Term Memory network for identifying offensive language in Twitter. Our system has been developed in the context of the SemEval 2019 Task 6 which comprises three different sub-tasks, namely A: Offensive Language Detection, B: Categorization of Offensive Language, C: Offensive Language Target Identification. We used a pre-trained Word Embeddings in tweet data, including information about emojis and hashtags. Our approach achieves good performance in the three sub-tasks.
Tasks Word Embeddings
Published 2019-06-01
URL https://www.aclweb.org/anthology/S19-2120/
PDF https://www.aclweb.org/anthology/S19-2120
PWC https://paperswithcode.com/paper/lastustaln-at-semeval-2019-task-6
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Prior-Free Dynamic Auctions with Low Regret Buyers

Title Prior-Free Dynamic Auctions with Low Regret Buyers
Authors Yuan Deng, Jon Schneider, Balasubramanian Sivan
Abstract We study the problem of how to repeatedly sell to a buyer running a no-regret, mean-based algorithm. Previous work [Braverman et al., 2018] shows that it is possible to design effective mechanisms in such a setting that extract almost all of the economic surplus, but these mechanisms require the buyer’s values each round to be drawn independently and identically from a fixed distribution. In this work, we do away with this assumption and consider the prior-free setting where the buyer’s value each round is chosen adversarially (possibly adaptively). We show that even in this prior-free setting, it is possible to extract a $(1-\varepsilon)$-approximation of the full economic surplus for any $\varepsilon > 0$. The number of options offered to a buyer in any round scales independently of the number of rounds $T$ and polynomially in $\varepsilon$. We show that this is optimal up to a polynomial factor; any mechanism achieving this approximation factor, even when values are drawn stochastically, requires at least $\Omega(1/\varepsilon)$ options. Finally, we examine what is possible when we constrain our mechanism to a natural auction format where overbidding is dominated. Braverman et al. [2018] show that even when values are drawn from a known stochastic distribution supported on $[1/H, 1]$, it is impossible in general to extract more than $O(\log\log H / \log H)$ of the economic surplus. We show how to achieve the same approximation factor in the prior-independent setting (where the distribution is unknown to the seller), and an approximation factor of $O(1 / \log H)$ in the prior-free setting (where the values are chosen adversarially).
Tasks
Published 2019-12-01
URL http://papers.nips.cc/paper/8727-prior-free-dynamic-auctions-with-low-regret-buyers
PDF http://papers.nips.cc/paper/8727-prior-free-dynamic-auctions-with-low-regret-buyers.pdf
PWC https://paperswithcode.com/paper/prior-free-dynamic-auctions-with-low-regret
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Artificial Error Generation with Fluency Filtering

Title Artificial Error Generation with Fluency Filtering
Authors Mengyang Qiu, Jungyeul Park
Abstract The quantity and quality of training data plays a crucial role in grammatical error correction (GEC). However, due to the fact that obtaining human-annotated GEC data is both time-consuming and expensive, several studies have focused on generating artificial error sentences to boost training data for grammatical error correction, and shown significantly better performance. The present study explores how fluency filtering can affect the quality of artificial errors. By comparing artificial data filtered by different levels of fluency, we find that artificial error sentences with low fluency can greatly facilitate error correction, while high fluency errors introduce more noise.
Tasks Grammatical Error Correction
Published 2019-08-01
URL https://www.aclweb.org/anthology/W19-4408/
PDF https://www.aclweb.org/anthology/W19-4408
PWC https://paperswithcode.com/paper/artificial-error-generation-with-fluency
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