Technology
Trailer Generation via a Point Process-Based Visual Attractiveness Model
Xu, Hongteng (Georgia Institute of Technology) | Zhen, Yi (Georgia Institute of Technology) | Zha, Hongyuan (Georgia Institute of Technology)
Producing attractive trailers for videos needs human expertise and creativity, and hence is challenging and costly. Different from video summarization that focuses on capturing storylines or important scenes, trailer generation aims at producing trailers that are attractive so that viewers will be eager to watch the original video. In this work, we study the problem of automatic trailer generation, in which an attractive trailer is produced given a video and a piece of music. We propose a surrogate measure of video attractiveness named fixation variance, and learn a novel self-correcting point process-based attractiveness model that can effectively describe the dynamics of attractiveness of a video. Furthermore, based on the attractiveness model learned from existing training trailers, we propose an efficient graph-based trailer generation algorithm to produce a max-attractiveness trailer. Experiments demonstrate that our approach outperforms the state-of-the-art trailer generators in terms of both quality and efficiency.
MergeXplain: Fast Computation of Multiple Conflicts for Diagnosis
Shchekotykhin, Kostyantyn (Alpen-Ardia University Klagenfurt) | Jannach, Dietmar (TU Dortmund) | Schmitz, Thomas (TU Dortmund)
The computation of minimal conflict sets is a central task when the goal is to find relaxations or explanations for overconstrained problem formulations and in particular in the context of Model-Based Diagnosis (MBD) approaches. In this paper we propose MergeXPlain, a non-intrusive conflict detection algorithm which implements a divide-and-conquer strategy to decompose a problem into a set of smaller independent subproblems. Our technique allows us to efficiently determine multiple minimal conflicts during one single problem decomposition run, which is particularly helpful in MBD problem settings. An empirical evaluation on various benchmark problems shows that our method can lead to a significant reduction of the required diagnosis times.
The Cube of Opposition: A Structure Underlying Many Knowledge Representation Formalisms
Dubois, Didier (IRIT, University of Toulouse) | Prade, Henri (IRIT, University of Toulouse) | Rico, Agnรจs (ERIC, Universitรฉ Claude Bernard Lyon 1)
The square of opposition is a structure involving two involutive negations and relating quantified statements, invented in Aristotle time. Rediscovered in the second half of the XXth century, and advocated as being of interest for understanding conceptual structures and solving problems in paraconsistent logics, the square of opposition has been recently completed into a cube, which corresponds to the introduction of a third negation. Such a cube can be encountered in very different knowledge representation formalisms, such as modal logic, possibility theory in its all-or-nothing version, formal concept analysis, rough set theory and abstract argumentation. After restating these results in a unified perspective, the paper proposes a graded extension of the cube and shows that several qualitative, as well as quantitative formalisms, such as Sugeno integrals used in multiple criteria aggregation and qualitative decision theory, or yet belief functions and Choquet integrals, are amenable to transformations that form graded cubes of opposition. This discovery leads to a new perspective on many knowledge representation formalisms, laying bare their underlying common features. The cube of opposition exhibits fruitful parallelisms between different formalisms, which leads to highlight some missing components present in one formalism and currently absent from another.
Planning for Stochastic Games with Co-Safe Objectives
Song, Lei (University of Technology Sydney) | Feng, Yuan (University of Technology Sydney) | Zhang, Lijun (Chinese Academy of Sciences)
We consider planning problems for stochastic games with objectives specified by a branching-time logic, called probabilistic computation tree logic (PCTL). This problem has been shown to be undecidable if strategies with perfect recall, i.e., history-dependent, are considered. In this paper, we show that, if restricted to co-safe properties, a subset of PCTL properties capable to specify a wide range of properties in practice including reachability ones, the problem turns to be decidable, even when the class of general strategies is considered. We also give an algorithm for solving robust stochastic planning, where a winning strategy is tolerant to some perturbations of probabilities in the model. Our result indicates that satisfiability of co-safe PCTL is decidable as well.
Distance-Bounded Consistent Query Answering
Pfandler, Andreas (Vienna University of Technology and University of Siegen) | Sallinger, Emanuel (Vienna University of Technology)
The ability to perform reasoning on inconsistent data is a central problem both for AI and database research. One approach to deal with this situation is consistent query answering, where queries are answered over all possible repairs of the database. In general, the repair may be very distant from the original database. In this work we present a new approach where this distance is bounded and analyze its computational complexity. Our results show that in many (but not all) cases the complexity drops.
Non-Myopic Negotiators See What's Best
Zick, Yair (Carnegie-Mellon University) | Bachrach, Yoram (Microsoft Research) | Kash, Ian A. (Microsoft Research) | Key, Peter (Microsoft Research)
We consider revenue negotiation problems in iterative settings. In our model, a group of agentshas some initial resources, used in order to generate revenue. Agents must agree on some way of dividing resources, but thereโs a twist. At every time-step, the revenue shares received at time t are agent resources at time t + 1, and the game is repeated. The key issue here is that the way resources are shared has a dramatic effect on long term social welfare, so in order to maximize individual long-term revenue one must consider the welfare of others, a behavior not captured by other models of cooperation and bargaining. Our work focuses on homogeneous production functions. We identify conditions that ensure that the socially optimal outcome is an epsilon-Nash equilibrium. We apply our results to some families of utility functions, and discuss their strategic implications.
Compiling Constraint Networks into Multivalued Decomposable Decision Graphs
Koriche, Frรฉdรฉric (CRIL-CNRS and Universitรฉ d'Artois) | Lagniez, Jean-Marie (CRIL-CNRS and Universitรฉ d'Artois) | Marquis, Pierre (CRIL-CNRS and Universitรฉ d'Artois) | Thomas, Samuel (CRIL-CNRS and Universitรฉ d'Artois)
Specifically, we present a top-down algorithm cn2mddg for compiling finite-domain CNs into multivalued decomposable We present and evaluate a top-down algorithm for decision graphs. The input of cn2mddg is a CN compiling finite-domain constraint networks (CNs) represented in the XCSP 2.1 format [Roussel and Lecoutre, into the language MDDG of multivalued decomposable 2009]. The output of our compilation algorithm is a representation decision graphs. Though it includes Decision-of the solutions of the CN in the language MDDG DNNF as a proper subset, MDDG offers the same key of multivalued decomposable decision graphs. MDDG is precisely tractable queries and transformations as Decision-the extension to non-Boolean domains of the language DNNF, which makes it useful for many applications. DDG [Fargier and Marquis, 2006] also known as Decision-Intensive experiments showed that our compiler DNNF [Oztok and Darwiche, 2014]: it is based on decomposable cn2mddg succeeds in compiling CNs which -nodes and (multivalued) decision nodes. Similarly are out of the reach of standard approaches based to Decision-DNNF, the MDDG language offers a number of on a translation of the input network to CNF, followed tractable queries, including (possibly weighted) solution finding by a compilation to Decision-DNNF. Furthermore, and counting, solution enumeration (solutions can be enumerated the sizes of the resulting compiled representations with polynomial delay), and optimization w.r.t. a linear turn out to be much smaller (sometimes by objective function. It also offers tractable transformations, several orders of magnitude).
Awards and Distinguished Papers
Yang, Qiang (Hong Kong University of Science and Technology)
Professor Higgins Professor of Natural Sciences at the School of Engineering and Natural Selman is recognized for expanding our understanding of problem Sciences, Harvard University. Professor Grosz is recognized for her pioneering complexity and developing new algorithms for efficient inference. Previous recipients have been Bernard outstanding young scientists in artificial intelligence. It is currently supported by income Grosz (2001), Alan Bundy (2003), Raj Reddy (2005), Ronald J. Brachman from IJCAI funds. Past recipients of this honor have been Terry (2007), Luigia Carlucci Aiello (2009), Raymond C. Perrault (2011), and Winograd (1971), Patrick Winston (1973), Chuck Rieger (1975), Douglas Wolfgang Wahlster (2013).
Representation Learning for Measuring Entity Relatedness with Rich Information
Zhao, Yu (Tsinghua University) | Liu, Zhiyuan (Tsinghua University) | Sun, Maosong (Tsinghua University)
Incorporating multiple types of relational information from heterogeneous networks has been proved effective in data mining. Although Wikipedia is one of the most famous heterogeneous network, previous works of semantic analysis on Wikipedia are mostly limited on single type of relations. In this paper, we aim at incorporating multiple types of relations to measure the semantic relatedness between Wikipedia entities. We propose a framework of coordinate matrix factorization to construct low-dimensional continuous representation for entities, categories and words in the same semantic space. We formulate this task as the completion of a sparse entity-entity association matrix, in which each entry quantifies the strength of relatedness between corresponding entities. We evaluate our model on the task of judging pair-wise word similarity. Experiment result shows that our model outperforms both traditional entity relatedness algorithms and other representation learning models.
Convergence to Equilibria in Strategic Candidacy
Polukarov, Maria (University of Southampton) | Obraztsova, Svetlana (Tel Aviv University) | Rabinovich, Zinovi (Mobileye Vision Technologies Ltd.) | Kruglyi, Alexander (St.Petersburg State Polytechnical University) | Jennings, Nicholas R. (University of Southampton)
We study equilibrium dynamics in candidacy games, in which candidates may strategically decide to enter the election or withdraw their candidacy, following their own preferences over possible outcomes. Focusing on games under Plurality, we extend the standard model to allow for situations where voters may refuse to return their votes to those candidates who had previously left the election, should they decide to run again. We show that if at the time when a candidate withdraws his candidacy, with some positive probability each voter takes this candidate out of his future consideration, the process converges with probability 1. This is in sharp contrast with the original model where the very existence of a Nash equilibrium is not guaranteed. We then consider the two extreme cases of this setting, where voters may block a withdrawn candidate with probabilities 0 or 1. In these scenarios, we study the complexity of reaching equilibria from a given initial point, converging to an equilibrium with a predermined winner or to an equilibrium with a given set of running candidates. Except for one easy case, we show that these problems are NP-complete, even when the initial point is fixed to a natural---truthful---state where all potential candidates stand for election.