Journal of Artificial Intelligence Research最新文献_第10页

Better Decision Heuristics in CDCL through Local Search and Target Phases 基于局部搜索和目标阶段的CDCL优化决策启发式

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-08-08 DOI: 10.1613/jair.1.13666

Shaowei Cai, Xindi Zhang, M. Fleury, Armin Biere

{"title":"Better Decision Heuristics in CDCL through Local Search and Target Phases","authors":"Shaowei Cai, Xindi Zhang, M. Fleury, Armin Biere","doi":"10.1613/jair.1.13666","DOIUrl":"https://doi.org/10.1613/jair.1.13666","url":null,"abstract":"On practical applications, state-of-the-art SAT solvers dominantly use the conflict-driven clause learning (CDCL) paradigm. An alternative for satisfiable instances is local search solvers, which is more successful on random and hard combinatorial instances. Although there have been attempts to combine these methods in one framework, a tight integration which improves the state of the art on a broad set of application instances has been missing. We present a combination of techniques that achieves such an improvement. Our first contribution is to maximize in a local search fashion the assignment trail in CDCL, by sticking to and extending promising assignments via a technique called target phases. Second, we relax the CDCL framework by again extending promising branches to complete assignments while ignoring conflicts. These assignments are then used as starting point of local search which tries to find improved assignments with fewer unsatisfied clauses. Third, these improved assignments are imported back to the CDCL loop where they are used to determine the value assigned to decision variables. Finally, the conflict frequency of variables in local search can be exploited during variable selection in branching heuristics of CDCL. We implemented these techniques to improve three representative CDCL solvers (Glucose, MapleLcm DistChronoBT, and Kissat). Experiments on benchmarks from the main tracks of the last three SAT Competitions from 2019 to 2021 and an additional benchmark set from spectrum allocation show that the techniques bring significant improvements, particularly and not surprisingly, on satisfiable real-world application instances. We claim that these techniques were essential to the large increase in performance witnessed in the SAT Competition 2020 where Kissat and Relaxed LcmdCbDl NewTech were leading the field followed by CryptoMiniSAT-Ccnr, which also incorporated similar ideas.","PeriodicalId":54877,"journal":{"name":"Journal of Artificial Intelligence Research","volume":"357 1","pages":"1515-1563"},"PeriodicalIF":5.0,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76317989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Improving Simulated Annealing for Clique Partitioning Problems 团划分问题的改进模拟退火

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-07-27 DOI: 10.1613/jair.1.13382

Jian Gao, Yiqi Lv, Minghao Liu, Shaowei Cai, Feifei Ma

{"title":"Improving Simulated Annealing for Clique Partitioning Problems","authors":"Jian Gao, Yiqi Lv, Minghao Liu, Shaowei Cai, Feifei Ma","doi":"10.1613/jair.1.13382","DOIUrl":"https://doi.org/10.1613/jair.1.13382","url":null,"abstract":"The Clique Partitioning Problem (CPP) is essential in graph theory with a number of important applications. Due to its NP-hardness, efficient algorithms for solving this problem are very crucial for practical purposes, and simulated annealing is proved to be effective in state-of-the-art CPP algorithms. However, to make simulated annealing more efficient to solve large-scale CPPs, in this paper, we propose a new iterated simulated annealing algorithm. Several methods are proposed in our algorithm to improve simulated annealing. First, a new configuration checking strategy based on timestamp is presented and incorporated into simulated annealing to avoid search cycles. Afterwards, to enhance the local search ability of simulated annealing and speed up convergence, we combine our simulated annealing with a descent search method to solve the CPP. This method further improves solutions found by simulated annealing, and thus compensates for the local search effect. To further accelerate the convergence speed, we introduce a shrinking factor to decline initial temperature and then propose an iterated local search algorithm based on simulated annealing. Additionally, a restart strategy is adopted when the search procedure converges. Extensive experiments on benchmark instances of the CPP were carried out, and the results suggest that the proposed simulated annealing algorithm outperforms all the existing heuristic algorithms, including five state-of-the-art algorithms. Thus the best-known solutions for 34 instances out of 94 are updated. We also conduct comparative analyses of the proposed strategies and show their effectiveness.","PeriodicalId":54877,"journal":{"name":"Journal of Artificial Intelligence Research","volume":"5 1","pages":"1485-1513"},"PeriodicalIF":5.0,"publicationDate":"2022-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85775921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Deciding FO-rewritability of Regular Languages and Ontology-Mediated Queries in Linear Temporal Logic 线性时序逻辑中正则语言和本体中介查询的fo -可重写性决定

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-07-13 DOI: 10.1613/jair.1.14061

Agi Kurucz, V. Ryzhikov, Yury Savateev, M. Zakharyaschev

{"title":"Deciding FO-rewritability of Regular Languages and Ontology-Mediated Queries in Linear Temporal Logic","authors":"Agi Kurucz, V. Ryzhikov, Yury Savateev, M. Zakharyaschev","doi":"10.1613/jair.1.14061","DOIUrl":"https://doi.org/10.1613/jair.1.14061","url":null,"abstract":"Our concern is the problem of determining the data complexity of answering an ontology-mediated query (OMQ) formulated in linear temporal logic LTL over (Z,<) and deciding whether it is rewritable to an FO(<)-query, possibly with some extra predicates. First, we observe that, in line with the circuit complexity and FO-definability of regular languages, OMQ answering in AC0, ACC0 and NC1 coincides with FO(<,≡)-rewritability using unary predicates x ≡ 0 (mod n), FO(<,MOD)-rewritability, and FO(RPR)-rewritability using relational primitive recursion, respectively. We prove that, similarly to known PSᴘᴀᴄᴇ-completeness of recognising FO(<)-definability of regular languages, deciding FO(<,≡)- and FO(<,MOD)-definability is also PSᴘᴀᴄᴇ-complete (unless ACC0 = NC1). We then use this result to show that deciding FO(<)-, FO(<,≡)- and FO(<,MOD)-rewritability of LTL OMQs is ExᴘSᴘᴀᴄᴇ-complete, and that these problems become PSᴘᴀᴄᴇ-complete for OMQs with a linear Horn ontology and an atomic query, and also a positive query in the cases of FO(<)- and FO(<,≡)-rewritability. Further, we consider FO(<)-rewritability of OMQs with a binary-clause ontology and identify OMQ classes, for which deciding it is PSᴘᴀᴄᴇ-, Π2p- and coNP-complete.","PeriodicalId":54877,"journal":{"name":"Journal of Artificial Intelligence Research","volume":"117 1","pages":"645-703"},"PeriodicalIF":5.0,"publicationDate":"2022-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79743005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

HEBO: An Empirical Study of Assumptions in Bayesian Optimisation HEBO:贝叶斯优化假设的实证研究

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-07-11 DOI: 10.1613/jair.1.13643

A. Cowen-Rivers, Wenlong Lyu, Rasul Tutunov, Zhi Wang, Antoine Grosnit, Ryan-Rhys Griffiths, A. Maraval, Jianye Hao, Jun Wang, Jan Peters, Haitham Bou-Ammar

{"title":"HEBO: An Empirical Study of Assumptions in Bayesian Optimisation","authors":"A. Cowen-Rivers, Wenlong Lyu, Rasul Tutunov, Zhi Wang, Antoine Grosnit, Ryan-Rhys Griffiths, A. Maraval, Jianye Hao, Jun Wang, Jan Peters, Haitham Bou-Ammar","doi":"10.1613/jair.1.13643","DOIUrl":"https://doi.org/10.1613/jair.1.13643","url":null,"abstract":"In this work we rigorously analyse assumptions inherent to black-box optimisation hyper-parameter tuning tasks. Our results on the Bayesmark benchmark indicate that heteroscedasticity and non-stationarity pose significant challenges for black-box optimisers. Based on these findings, we propose a Heteroscedastic and Evolutionary Bayesian Optimisation solver (HEBO). HEBO performs non-linear input and output warping, admits exact marginal log-likelihood optimisation and is robust to the values of learned parameters. We demonstrate HEBO’s empirical efficacy on the NeurIPS 2020 Black-Box Optimisation challenge, where HEBO placed first. Upon further analysis, we observe that HEBO significantly outperforms existing black-box optimisers on 108 machine learning hyperparameter tuning tasks comprising the Bayesmark benchmark. Our findings indicate that the majority of hyper-parameter tuning tasks exhibit heteroscedasticity and non-stationarity, multiobjective acquisition ensembles with Pareto front solutions improve queried configurations, and robust acquisition maximisers afford empirical advantages relative to their non-robust counterparts. We hope these findings may serve as guiding principles for practitioners of Bayesian optimisation.","PeriodicalId":54877,"journal":{"name":"Journal of Artificial Intelligence Research","volume":"11 1","pages":"1269-1349"},"PeriodicalIF":5.0,"publicationDate":"2022-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78883366","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Evolutionary Dynamics and Phi-Regret Minimization in Games 游戏中的进化动力学和phi -遗憾最小化

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-07-08 DOI: 10.1613/jair.1.13187

G. Piliouras, Mark Rowland, Shayegan Omidshafiei, R. Élie, Daniel Hennes, Jerome T. Connor, K. Tuyls

{"title":"Evolutionary Dynamics and Phi-Regret Minimization in Games","authors":"G. Piliouras, Mark Rowland, Shayegan Omidshafiei, R. Élie, Daniel Hennes, Jerome T. Connor, K. Tuyls","doi":"10.1613/jair.1.13187","DOIUrl":"https://doi.org/10.1613/jair.1.13187","url":null,"abstract":"Regret has been established as a foundational concept in online learning, and likewise has important applications in the analysis of learning dynamics in games. Regret quantifies the difference between a learner’s performance against a baseline in hindsight. It is well known that regret-minimizing algorithms converge to certain classes of equilibria in games; however, traditional forms of regret used in game theory predominantly consider baselines that permit deviations to deterministic actions or strategies. In this paper, we revisit our understanding of regret from the perspective of deviations over partitions of the full mixed strategy space (i.e., probability distributions over pure strategies), under the lens of the previously-established Φ-regret framework, which provides a continuum of stronger regret measures. Importantly, Φ-regret enables learning agents to consider deviations from and to mixed strategies, generalizing several existing notions of regret such as external, internal, and swap regret, and thus broadening the insights gained from regret-based analysis of learning algorithms. We prove here that the well-studied evolutionary learning algorithm of replicator dynamics (RD) seamlessly minimizes the strongest possible form of Φ-regret in generic 2 × 2 games, without any modification of the underlying algorithm itself. We subsequently conduct experiments validating our theoretical results in a suite of 144 2 × 2 games wherein RD exhibits a diverse set of behaviors. We conclude by providing empirical evidence of Φ-regret minimization by RD in some larger games, hinting at further opportunity for Φ-regret based study of such algorithms from both a theoretical and empirical perspective.","PeriodicalId":54877,"journal":{"name":"Journal of Artificial Intelligence Research","volume":"99 1","pages":"1125-1158"},"PeriodicalIF":5.0,"publicationDate":"2022-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89541019","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

A Comprehensive Framework for Learning Declarative Action Models 学习陈述性行动模型的综合框架

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-07-07 DOI: 10.1613/jair.1.13073

Diego Aineto, Sergio Jiménez, E. Onaindía

引用次数: 4

Two-phase Multi-document Event Summarization on Core Event Graphs 核心事件图上的两阶段多文档事件摘要

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-07-05 DOI: 10.1613/jair.1.13267

Zengjian Chen, Jin Xu, M. Liao, Tong Xue, Kun He

{"title":"Two-phase Multi-document Event Summarization on Core Event Graphs","authors":"Zengjian Chen, Jin Xu, M. Liao, Tong Xue, Kun He","doi":"10.1613/jair.1.13267","DOIUrl":"https://doi.org/10.1613/jair.1.13267","url":null,"abstract":"Succinct event description based on multiple documents is critical to news systems as well as search engines. Different from existing summarization or event tasks, Multi-document Event Summarization (MES) aims at the query-level event sequence generation, which has extra constraints on event expression and conciseness. Identifying and summarizing the key event from a set of related articles is a challenging task that has not been sufficiently studied, mainly because online articles exhibit characteristics of redundancy and sparsity, and a perfect event summarization needs high level information fusion among diverse sentences and articles. To address these challenges, we propose a two-phase framework for the MES task, that first performs event semantic graph construction and dominant event detection via graph-sequence matching, then summarizes the extracted key event by an event-aware pointer generator. For experiments in the new task, we construct two large-scale real-world datasets for training and assessment. Extensive evaluations show that the proposed framework significantly outperforms the related baseline methods, with the most dominant event of the articles effectively identified and correctly summarized.","PeriodicalId":54877,"journal":{"name":"Journal of Artificial Intelligence Research","volume":"4 1","pages":"1037-1057"},"PeriodicalIF":5.0,"publicationDate":"2022-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90044099","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

On Dynamics in Structured Argumentation Formalisms 论结构化论证形式主义的动态性

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-07-01 DOI: 10.24963/kr.2022/29

Anna Rapberger, Markus Ulbricht

{"title":"On Dynamics in Structured Argumentation Formalisms","authors":"Anna Rapberger, Markus Ulbricht","doi":"10.24963/kr.2022/29","DOIUrl":"https://doi.org/10.24963/kr.2022/29","url":null,"abstract":"In this paper we contribute to the investigation of dynamics in assumption-based argumentation (ABA) and investigate situations where a given knowledge base undergoes certain changes. We show that two frequently investigated problems, namely enforcement of a given target atom and deciding strong equivalence of two given ABA frameworks, are intractable in general. Interestingly, these problems are both tractable for abstract argumentation frameworks (AFs) which admit a close correspondence to ABA by constructing semantics-preserving instances. Inspired by this observation, we search for tractable fragments for ABA frameworks by means of the instantiated AFs. We argue that the usual instantiation procedure is not suitable for the investigation of dynamic scenarios since too much information is lost when constructing the AF. We thus consider an extension of AFs, called cvAFs, equipping arguments with conclusions and vulnerabilities in order to better anticipate their role after the underlying knowledge base is extended. We investigate enforcement and strong equivalence for cvAFs and present syntactic conditions to decide them. We show that the correspondence between cvAFs and ABA frameworks is close enough to capture ABA also in dynamic scenarios. This yields the desired tractable ABA fragment. We furthermore discuss consequences for the corresponding problems for logic programs.","PeriodicalId":54877,"journal":{"name":"Journal of Artificial Intelligence Research","volume":"1983 1","pages":"563-643"},"PeriodicalIF":5.0,"publicationDate":"2022-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90303440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Equivalence in Argumentation Frameworks with a Claim-Centric View - Classical Results with Novel Ingredients 以主张为中心的论证框架中的等价性——具有新成分的经典结果

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-06-28 DOI: 10.1609/aaai.v36i5.20486

Ringo Baumann, Anna Rapberger, Markus Ulbricht

{"title":"Equivalence in Argumentation Frameworks with a Claim-Centric View - Classical Results with Novel Ingredients","authors":"Ringo Baumann, Anna Rapberger, Markus Ulbricht","doi":"10.1609/aaai.v36i5.20486","DOIUrl":"https://doi.org/10.1609/aaai.v36i5.20486","url":null,"abstract":"A common feature of non-monotonic logics is that the classical notion of equivalence does not preserve the intended meaning in light of additional information. Consequently, the term strong equivalence was coined in the literature and thoroughly investigated. In the present paper, the knowledge representation formalism under consideration are claim-augmented argumentation frameworks (CAFs) which provide a formal basis to analyze conclusion-oriented problems in argumentation by adapting a claim-focused perspective. CAFs extend Dung AFs by associating a claim to each argument representing its conclusion. In this paper, we investigate both ordinary and strong equivalence in CAFs. Thereby, we take the fact into account that one might either be interested in the actual arguments or their claims only. The former point of view naturally yields an extension of strong equivalence for AFs to the claim-based setting while the latter gives rise to a novel equivalence notion which is genuine for CAFs. We tailor, examine and compare these notions and obtain a comprehensive study of this matter for CAFs. We conclude by investigating the computational complexity of naturally arising decision problems.","PeriodicalId":54877,"journal":{"name":"Journal of Artificial Intelligence Research","volume":"49 1","pages":"891-948"},"PeriodicalIF":5.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77912140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Path Counting for Grid-Based Navigation 基于网格导航的路径计数

IF 5 3区计算机科学

Journal of Artificial Intelligence Research Pub Date : 2022-06-25 DOI: 10.1613/jair.1.13544

Rhys Goldstein, Kean Walmsley, Jacobo Bibliowicz, Alex Tessier, Simon Breslav, Azam Khan

{"title":"Path Counting for Grid-Based Navigation","authors":"Rhys Goldstein, Kean Walmsley, Jacobo Bibliowicz, Alex Tessier, Simon Breslav, Azam Khan","doi":"10.1613/jair.1.13544","DOIUrl":"https://doi.org/10.1613/jair.1.13544","url":null,"abstract":"Counting the number of shortest paths on a grid is a simple procedure with close ties to Pascal’s triangle. We show how path counting can be used to select relatively direct grid paths for AI-related applications involving navigation through spatial environments. Typical implementations of Dijkstra’s algorithm and A* prioritize grid moves in an arbitrary manner, producing paths which stray conspicuously far from line-of-sight trajectories. We find that by counting the number of paths which traverse each vertex, then selecting the vertices with the highest counts, one obtains a path that is reasonably direct in practice and can be improved by refining the grid resolution. Central Dijkstra and Central A* are introduced as the basic methods for computing these central grid paths. Theoretical analysis reveals that the proposed grid-based navigation approach is related to an existing grid-based visibility approach, and establishes that central grid paths converge on clear sightlines as the grid spacing approaches zero. A more general property, that central paths converge on direct paths, is formulated as a conjecture.","PeriodicalId":54877,"journal":{"name":"Journal of Artificial Intelligence Research","volume":"21 1","pages":"917-955"},"PeriodicalIF":5.0,"publicationDate":"2022-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89071479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4