Asia
Solving Constrained Combinatorial Optimisation Problems via MAP Inference without High-Order Penalties
Zhang, Zhen (Northwestern Polytechnical University) | Shi, Qinfeng (The University of Adelaide) | McAuley, Julian (University of California, San Diego) | Wei, Wei (Northwestern Polytechnical University) | Zhang, Yanning (Northwestern Polytechnical University) | Yao, Rui (China University of Mining and Technology) | Hengel, Anton van den (The University of Adelaide)
Solving constrained combinatorial optimisation problems via MAP inference is often achieved by introducing extra potential functions for each constraint. This can result in very high order potentials, e.g. a 2nd-order objective with pairwise potentials and a quadratic constraint over all N variables would correspond to an unconstrained objective with an order-N potential. This limits the practicality of such an approach, since inference with high order potentials is tractable only for a few special classes of functions. We propose an approach which is able to solve constrained combinatorial problems using belief propagation without increasing the order. For example, in our scheme the 2nd-order problem above remains order 2 instead of order N. Experiments on applications ranging from foreground detection, image reconstruction, quadratic knapsack, and the M-best solutions problem demonstrate the effectiveness and efficiency of our method. Moreover, we show several situations in which our approach outperforms commercial solvers like CPLEX and others designed for specific constrained MAP inference problems.
Decentralized Planning in Stochastic Environments with Submodular Rewards
Kumar, Rajiv Ranjan (Singapore Management University) | Varakantham, Pradeep (Singapore Management University) | Kumar, Akshat (Singapore Management University)
Decentralized Markov Decision Process (Dec-MDP) provides a rich framework to represent cooperative decentralized and stochastic planning problems under transition uncertainty. However, solving a Dec-MDP to generate coordinated yet decentralized policies is NEXP-Hard. Researchers have made significant progress in providing approximate approaches to improve scalability with respect to number of agents. However, there has been little or no research devoted to finding guarantees on solution quality for approximate approaches considering multiple (more than 2 agents) agents. We have a similar situation with respect to the competitive decentralized planning problem and the Stochastic Game (SG) model. To address this, we identify models in the cooperative and competitive case that rely on submodular rewards, where we show that existing approximate approaches can provide strong quality guarantees ( a priori, and for cooperative case also posteriori guarantees). We then provide solution approaches and demonstrate improved online guarantees on benchmark problems from the literature for the cooperative case.
Nash Stability in Social Distance Games
Balliu, Alkida (Gran Sasso Science Institute) | Flammini, Michele (University of L'Aquila and Gran Sasso Science Institute) | Melideo, Giovanna (University of L'Aquila) | Olivetti, Dennis (Gran Sasso Science Institute)
In this paper we focus on Social Distance Games (SDGs), Coalition formation is a pervasive aspect of social life and an important subclass of HGs introduced in (Brânzei and it has been studied extensively in algorithmic game theory Larson 2011) where agent utilities are based on the concept using the natural model of Hedonic Games (HGs), introduced of social distance (i.e., the number of hops required to reach in (Dreze and Greenberg 1980) and further explored one node from another), which has become famous since in (Aziz, Brandt, and Harrenstein 2011; Aziz, Brandt, and Milgram's study on six degrees of separation. In SDGs the Seedig 2013; Banerjee, Konishi, and Sönmez 2001; Bogomolnaia utility of an agent is given by the average inverse distance and Jackson 2002; Elkind and Wooldridge 2009; from all the other nodes in her coalition, that is by her harmonic Elkind, Fanelli, and Flammini 2016; Gairing and Savani centrality (Boldi and Vigna 2014) divided by the size 2010). A HG consists of a set of selfish agents (humans, of the coalition. The basic idea is that the agents prefer to robots, software agents, etc.) having preferences over coalitions maintain ties with other agents who are close to them. The that might include them, regardless of which other utility formulation is a variant of the closeness centrality and coalitions may or may not be present. The outcome is a partition reflects the principle of homophily, that similarity breeds of the agent set into disjoint coalitions (or clusters), connection and people tend to form communities with similar referred to as a clustering or coalition structure.
Beyond Monte Carlo Tree Search: Playing Go with Deep Alternative Neural Network and Long-Term Evaluation
Wang, Jinzhuo (Peking University) | Wang, Wenmin (Peking University ) | Wang, Ronggang (Peking University) | Gao, Wen (Peking University)
Monte Carlo tree search (MCTS) is extremely popular in computer Go which determines each action by enormous simulations in a broad and deep search tree. However, human experts select most actions by pattern analysis and careful evaluation rather than brute search of millions of future interactions. In this paper, we propose a computer Go system that follows experts’ way of thinking and playing. Our system consists of two parts. The first part is a novel deep alternative neural network (DANN) used to generate candidates of next move. Compared with existing deep convolutional neural network (DCNN), DANN inserts recurrent layer after each convolutional layer and stacks them in an alternative manner. We show such setting can preserve more contexts of local features and its evolutions which are beneficial for move prediction. The second part is a long-term evaluation (LTE) module used to provide a reliable evaluation of candidates rather than a single probability from move predictor. This is consistent with human experts’ nature of playing since they can foresee tens of steps to give an accurate estimation of candidates. In our system, for each candidate, LTE calculates a cumulative reward after several future interactions when local variations are settled. Combining criteria from the two parts, our system determines the optimal choice of next move. For more comprehensive experiments, we introduce a new professional Go dataset (PGD), consisting of $253,233$ professional records. Experiments on GoGoD and PGD datasets show the DANN can substantially improve performance of move prediction over pure DCNN. When combining LTE, our system outperforms most relevant approaches and open engines based on MCTS.
BattRAE: Bidimensional Attention-Based Recursive Autoencoders for Learning Bilingual Phrase Embeddings
Zhang, Biao (Xiamen University) | Xiong, Deyi (Soochow University) | Su, Jinsong (Xiamen University)
In this paper, we propose a bidimensional attention based recursiveautoencoder (BattRAE) to integrate clues and sourcetargetinteractions at multiple levels of granularity into bilingualphrase representations. We employ recursive autoencodersto generate tree structures of phrases with embeddingsat different levels of granularity (e.g., words, sub-phrases andphrases). Over these embeddings on the source and targetside, we introduce a bidimensional attention network to learntheir interactions encoded in a bidimensional attention matrix,from which we extract two soft attention weight distributionssimultaneously. These weight distributions enableBattRAE to generate compositive phrase representations viaconvolution. Based on the learned phrase representations, wefurther use a bilinear neural model, trained via a max-marginmethod, to measure bilingual semantic similarity. To evaluatethe effectiveness of BattRAE, we incorporate this semanticsimilarity as an additional feature into a state-of-the-art SMTsystem. Extensive experiments on NIST Chinese-English testsets show that our model achieves a substantial improvementof up to 1.63 BLEU points on average over the baseline.
Bootstrapping Distantly Supervised IE Using Joint Learning and Small Well-Structured Corpora
Bing, Lidong (Tencent Inc.) | Dhingra, Bhuwan (Carnegie Mellon University) | Mazaitis, Kathryn (Carnegie Mellon University) | Park, Jong Hyuk (Carnegie Mellon University) | Cohen, William W. (Carnegie Mellon University)
We propose a framework to improve the performance of distantly-supervised relation extraction, by jointly learning to solve two related tasks: concept-instance extraction and relation extraction. We further extend this framework to make a novel use of document structure: in some small, well-structured corpora, sections can be identified that correspond to relation arguments, and distantly-labeled examples from such sections tend to have good precision. Using these as seeds we extract additional relation examples by applying label propagation on a graph composed of noisy examples extracted from a large unstructured testing corpus. Combined with the soft constraint that concept examples should have the same type as the second argument of the relation, we get significant improvements over several state-of-the-art approaches to distantly-supervised relation extraction, and reasonable extraction performance even with very small set of distant labels.
The Unusual Suspects: Deep Learning Based Mining of Interesting Entity Trivia from Knowledge Graphs
Fatma, Nausheen (International Institute of Information Technology, Hyderabad) | Chinnakotla, Manoj K. (Microsoft, India) | Shrivastava, Manish (International Institute of Information Technology, Hyderabad)
Trivia is any fact about an entity which is interesting due to its unusualness, uniqueness or unexpectedness. Trivia could be successfully employed to promote user engagement in various product experiences featuring the given entity. A Knowledge Graph (KG) is a semantic network which encodes various facts about entities and their relationships. In this paper, we propose a novel approach called DBpedia Trivia Miner (DTM) to automatically mine trivia for entities of a given domain in KGs. The essence of DTM lies in learning an Interestingness Model (IM), for a given domain, from human annotated training data provided in the form of interesting facts from the KG. The IM thus learnt is applied to extract trivia for other entities of the same domain in the KG. We propose two different approaches for learning the IM - a) A Convolutional Neural Network (CNN) based approach and b) Fusion Based CNN (F-CNN) approach which combines both hand-crafted and CNN features. Experiments across two different domains - Bollywood Actors and Music Artists reveal that CNN automatically learns features which are relevant to the task and shows competitive performance relative to hand-crafted feature based baselines whereas F-CNN significantly improves the performance over the baseline approaches which use hand-crafted features alone. Overall, DTM achieves an F1 score of 0.81 and 0.65 in Bollywood Actors and Music Artists domains respectively.
A Virtual Personal Fashion Consultant: Learning from the Personal Preference of Fashion
Fu, Jingtian (Tsinghua University) | Liu, Yejun (Tsinghua University) | Jia, Jia (Tsinghua University) | Ma, Yihui (Tsinghua University) | Meng, Fanhang (Tsinghua University) | Huang, Huan (Tsinghua University)
Besides fashion, personalization is another important factor of wearing. How to balance fashion trend and personal preference to better appreciate wearing is a non-trivial task. In previous work we develop a demo, Magic Mirror, to recommend clothing collocation based on the fashion trend. However, the diversity of people’s aesthetics is huge. In order to meet different demand, Magic Mirror is upgraded in this paper, and it can give out recommendations by considering both the fashion trend and personal preference, and work as a private clothing consultant. For more suitable recommendation, the virtual consultant will learn users’ tastes and preferences from their behaviors by using Genetic algorithm. Users can get collocations or matched top/bottom recommendation after choosing occasion and style. They can also get a report about their fashion state and aesthetic standpoint on recent wearing.
Automated Negotiating Agents Competition (ANAC)
Jonker, Catholijn M. (TU Delft) | Aydogan, Reyhan (Ozeygin University) | Baarslag, Tim (Centrum voor Wiskunde en Informatica) | Fujita, Katsuhide (Tokyo University of Agriculture and Technology) | Ito, Takayuki (Nagoya Institute of Technology) | Hindriks, Koen (TU Delft)
The annual International Automated Negotiating Agents Competition (ANAC) is used by the automated negotiation research community to benchmark and evaluate its work andto challenge itself. The benchmark problems and evaluation results and the protocols and strategies developed are available to the wider research community.
Problems in Large-Scale Image Classification
Guo, Yuchen (Tsinghua Univerisity)
The number of images is growing rapidly in recent years because of development of Internet, especially the social networks like Facebook, and the popularization of portable image capture devices like smart phone. Annotating them with semantically meaningful words to describe them, i.e., classification, is a useful way to manage these images. However, the huge number of images and classes brings several challenges to classification, of which two are 1) how to measure the similarity efficiently between large-scale images, for example, measuring similarity between samples is the building block for SVM and kNN classifiers, and 2) how to train supervised classification models for newly emerging classes with only a few or even no labeled samples because new concepts appear every day in the Web, like Tesla's Model S. The research of my Ph. D. thesis focuses on the two problems in large-scale image classification mentioned above. Formally, these two problems are termed as large-scale similarity search which focuses on the large scale of samples/images and zero-shot/few-shots learning which focuses on the large scale of classes. Specifically, my research considers the following three aspects: 1) hashing based large-scale similarity search which adopts hashing to improve the efficiency; 2) cross-class transfer active learning which simultaneously transfers knowledge from the abundant labeled samples in the Web and selects the most informative samples for expert labeling such that we can construct effective classifiers for novel classes with only a few labeled samples; and 3) zero-shot learning which utilizes no labeled samples for novel classes at all to build supervised classifiers for them by transferring knowledge from the related classes.