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1311.7139
Florentin Smarandache
Florentin Smarandache
Introduction to Neutrosophic Measure, Neutrosophic Integral, and Neutrosophic Probability
140 pages. 10 figures
Published as a book by Sitech in 2013
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we introduce for the first time the notions of neutrosophic measure and neutrosophic integral, and we develop the 1995 notion of neutrosophic probability. We present many practical examples. It is possible to define the neutrosophic measure and consequently the neutrosophic integral and neutrosophic probability in many ways, because there are various types of indeterminacies, depending on the problem we need to solve. Neutrosophics study the indeterminacy. Indeterminacy is different from randomness. It can be caused by physical space materials and type of construction, by items involved in the space, etc.
[ { "version": "v1", "created": "Wed, 27 Nov 2013 18:56:03 GMT" } ]
1,385,942,400,000
[ [ "Smarandache", "Florentin", "" ] ]
1312.0144
Yanjing Wang
Jie Fan, Yanjing Wang, Hans van Ditmarsch
Knowing Whether
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Knowing whether a proposition is true means knowing that it is true or knowing that it is false. In this paper, we study logics with a modal operator Kw for knowing whether but without a modal operator K for knowing that. This logic is not a normal modal logic, because we do not have Kw (phi -> psi) -> (Kw phi -> Kw psi). Knowing whether logic cannot define many common frame properties, and its expressive power less than that of basic modal logic over classes of models without reflexivity. These features make axiomatizing knowing whether logics non-trivial. We axiomatize knowing whether logic over various frame classes. We also present an extension of knowing whether logic with public announcement operators and we give corresponding reduction axioms for that. We compare our work in detail to two recent similar proposals.
[ { "version": "v1", "created": "Sat, 30 Nov 2013 19:18:49 GMT" }, { "version": "v2", "created": "Wed, 11 Dec 2013 13:19:33 GMT" }, { "version": "v3", "created": "Thu, 12 Dec 2013 10:02:26 GMT" } ]
1,386,892,800,000
[ [ "Fan", "Jie", "" ], [ "Wang", "Yanjing", "" ], [ "van Ditmarsch", "Hans", "" ] ]
1312.0735
Jean-Baptiste Lamy
Jean-Baptiste Lamy (LIM\&BIO), Anis Ellini (LIM\&BIO), Vahid Ebrahiminia, Jean-Daniel Zucker (UMMISCO), Hector Falcoff (SFTG), Alain Venot (LIM\&BIO)
Use of the C4.5 machine learning algorithm to test a clinical guideline-based decision support system
null
Studies in Health Technology and Informatics 136 (2008) 223-8
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Well-designed medical decision support system (DSS) have been shown to improve health care quality. However, before they can be used in real clinical situations, these systems must be extensively tested, to ensure that they conform to the clinical guidelines (CG) on which they are based. Existing methods cannot be used for the systematic testing of all possible test cases. We describe here a new exhaustive dynamic verification method. In this method, the DSS is considered to be a black box, and the Quinlan C4.5 algorithm is used to build a decision tree from an exhaustive set of DSS input vectors and outputs. This method was successfully used for the testing of a medical DSS relating to chronic diseases: the ASTI critiquing module for type 2 diabetes.
[ { "version": "v1", "created": "Tue, 3 Dec 2013 08:59:02 GMT" } ]
1,386,115,200,000
[ [ "Lamy", "Jean-Baptiste", "", "LIM\\&BIO" ], [ "Ellini", "Anis", "", "LIM\\&BIO" ], [ "Ebrahiminia", "Vahid", "", "UMMISCO" ], [ "Zucker", "Jean-Daniel", "", "UMMISCO" ], [ "Falcoff", "Hector", "", "SFTG" ], [ "Venot", "Alain", "", "LIM\\&BIO" ] ]
1312.0736
Jean-Baptiste Lamy
Jean-Baptiste Lamy (LIM\&BIO), Vahid Ebrahiminia, Brigitte Seroussi (LIM\&BIO), Jacques Bouaud, Christian Simon (LIM\&BIO), Madeleine Favre (SFTG), Hector Falcoff (SFTG), Alain Venot (LIM\&BIO)
A generic system for critiquing physicians' prescriptions: usability, satisfaction and lessons learnt
null
Studies in Health Technology and Informatics 169 (2011) 125-9
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Clinical decision support systems have been developed to help physicians to take clinical guidelines into account during consultations. The ASTI critiquing module is one such systems; it provides the physician with automatic criticisms when a drug prescription does not follow the guidelines. It was initially developed for hypertension and type 2 diabetes, but is designed to be generic enough for application to all chronic diseases. We present here the results of usability and satisfaction evaluations for the ASTI critiquing module, obtained with GPs for a newly implemented guideline concerning dyslipaemia, and we discuss the lessons learnt and the difficulties encountered when building a generic DSS for critiquing physicians' prescriptions.
[ { "version": "v1", "created": "Tue, 3 Dec 2013 08:59:47 GMT" } ]
1,386,115,200,000
[ [ "Lamy", "Jean-Baptiste", "", "LIM\\&BIO" ], [ "Ebrahiminia", "Vahid", "", "LIM\\&BIO" ], [ "Seroussi", "Brigitte", "", "LIM\\&BIO" ], [ "Bouaud", "Jacques", "", "LIM\\&BIO" ], [ "Simon", "Christian", "", "LIM\\&BIO" ], [ "Favre", "Madeleine", "", "SFTG" ], [ "Falcoff", "Hector", "", "SFTG" ], [ "Venot", "Alain", "", "LIM\\&BIO" ] ]
1312.0841
Ben Ruijl
Ben Ruijl and Jos Vermaseren and Aske Plaat and Jaap van den Herik
Combining Simulated Annealing and Monte Carlo Tree Search for Expression Simplification
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In many applications of computer algebra large expressions must be simplified to make repeated numerical evaluations tractable. Previous works presented heuristically guided improvements, e.g., for Horner schemes. The remaining expression is then further reduced by common subexpression elimination. A recent approach successfully applied a relatively new algorithm, Monte Carlo Tree Search (MCTS) with UCT as the selection criterion, to find better variable orderings. Yet, this approach is fit for further improvements since it is sensitive to the so-called exploration-exploitation constant $C_p$ and the number of tree updates $N$. In this paper we propose a new selection criterion called Simulated Annealing UCT (SA-UCT) that has a dynamic exploration-exploitation parameter, which decreases with the iteration number $i$ and thus reduces the importance of exploration over time. First, we provide an intuitive explanation in terms of the exploration-exploitation behavior of the algorithm. Then, we test our algorithm on three large expressions of different origins. We observe that SA-UCT widens the interval of good initial values $C_p$ where best results are achieved. The improvement is large (more than a tenfold) and facilitates the selection of an appropriate $C_p$.
[ { "version": "v1", "created": "Tue, 3 Dec 2013 14:56:28 GMT" } ]
1,386,115,200,000
[ [ "Ruijl", "Ben", "" ], [ "Vermaseren", "Jos", "" ], [ "Plaat", "Aske", "" ], [ "Herik", "Jaap van den", "" ] ]
1312.1146
Anna Roub\'i\v{c}kov\'a
Anna Roub\'i\v{c}kov\'a and Ivan Serina
Case-Based Merging Techniques in OAKPLAN
preliminary version
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Case-based planning can take advantage of former problem-solving experiences by storing in a plan library previously generated plans that can be reused to solve similar planning problems in the future. Although comparative worst-case complexity analyses of plan generation and reuse techniques reveal that it is not possible to achieve provable efficiency gain of reuse over generation, we show that the case-based planning approach can be an effective alternative to plan generation when similar reuse candidates can be chosen.
[ { "version": "v1", "created": "Wed, 4 Dec 2013 13:10:45 GMT" } ]
1,386,201,600,000
[ [ "Roubíčková", "Anna", "" ], [ "Serina", "Ivan", "" ] ]
1312.1887
Julio Lemos
Julio Lemos
Constraints on the search space of argumentation
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Drawing from research on computational models of argumentation (particularly the Carneades Argumentation System), we explore the graphical representation of arguments in a dispute; then, comparing two different traditions on the limits of the justification of decisions, and devising an intermediate, semi-formal, model, we also show that it can shed light on the theory of dispute resolution. We conclude our paper with an observation on the usefulness of highly constrained reasoning for Online Dispute Resolution systems. Restricting the search space of arguments exclusively to reasons proposed by the parties (vetoing the introduction of new arguments by the human or artificial arbitrator) is the only way to introduce some kind of decidability -- together with foreseeability -- in the argumentation system.
[ { "version": "v1", "created": "Fri, 6 Dec 2013 15:21:10 GMT" } ]
1,386,547,200,000
[ [ "Lemos", "Julio", "" ] ]
1312.1971
Sarwat Nizamani
Sarwat Nizamani, Nasrullah Memon, Uffe Kock Wiil, Panagiotis Karampelas
Modeling Suspicious Email Detection using Enhanced Feature Selection
null
IJMO 2012 Vol.2(4): 371-377 ISSN: 2010-3697
null
null
cs.AI
http://creativecommons.org/licenses/by-nc-sa/3.0/
The paper presents a suspicious email detection model which incorporates enhanced feature selection. In the paper we proposed the use of feature selection strategies along with classification technique for terrorists email detection. The presented model focuses on the evaluation of machine learning algorithms such as decision tree (ID3), logistic regression, Na\"ive Bayes (NB), and Support Vector Machine (SVM) for detecting emails containing suspicious content. In the literature, various algorithms achieved good accuracy for the desired task. However, the results achieved by those algorithms can be further improved by using appropriate feature selection mechanisms. We have identified the use of a specific feature selection scheme that improves the performance of the existing algorithms.
[ { "version": "v1", "created": "Fri, 6 Dec 2013 19:25:33 GMT" } ]
1,386,547,200,000
[ [ "Nizamani", "Sarwat", "" ], [ "Memon", "Nasrullah", "" ], [ "Wiil", "Uffe Kock", "" ], [ "Karampelas", "Panagiotis", "" ] ]
1312.2242
Nikolaos Mavridis
N. Mavridis, S. Konstantopoulos, I. Vetsikas, I. Heldal, P. Karampiperis, G. Mathiason, S. Thill, K. Stathis, V. Karkaletsis
CLIC: A Framework for Distributed, On-Demand, Human-Machine Cognitive Systems
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Traditional Artificial Cognitive Systems (for example, intelligent robots) share a number of limitations. First, they are usually made up only of machine components; humans are only playing the role of user or supervisor. And yet, there are tasks in which the current state of the art of AI has much worse performance or is more expensive than humans: thus, it would be highly beneficial to have a systematic way of creating systems with both human and machine components, possibly with remote non-expert humans providing short-duration real-time services. Second, their components are often dedicated to only one system, and underutilized for a big part of their lifetime. Third, there is no inherent support for robust operation, and if a new better component becomes available, one cannot easily replace the old component. Fourth, they are viewed as a resource to be developed and owned, not as a utility. Thus, we are presenting CLIC: a framework for constructing cognitive systems that overcome the above limitations. The architecture of CLIC provides specific mechanisms for creating and operating cognitive systems that fulfill a set of desiderata: First, that are distributed yet situated, interacting with the physical world though sensing and actuation services, and that are also combining human as well as machine services. Second, that are made up of components that are time-shared and re-usable. Third, that provide increased robustness through self-repair. Fourth, that are constructed and reconstructed on the fly, with components that dynamically enter and exit the system during operation, on the basis of availability, pricing, and need. Importantly, fifth, the cognitive systems created and operated by CLIC do not need to be owned and can be provided on demand, as a utility; thus transforming human-machine situated intelligence to a service, and opening up many interesting opportunities.
[ { "version": "v1", "created": "Sun, 8 Dec 2013 18:53:58 GMT" } ]
1,386,633,600,000
[ [ "Mavridis", "N.", "" ], [ "Konstantopoulos", "S.", "" ], [ "Vetsikas", "I.", "" ], [ "Heldal", "I.", "" ], [ "Karampiperis", "P.", "" ], [ "Mathiason", "G.", "" ], [ "Thill", "S.", "" ], [ "Stathis", "K.", "" ], [ "Karkaletsis", "V.", "" ] ]
1312.2506
Daniela Inclezan
Daniela Inclezan
An Application of Answer Set Programming to the Field of Second Language Acquisition
17 pages, 3 tables, to appear in Theory and Practice of Logic Programming (TPLP)
Theory and Practice of Logic Programming 15 (2015) 1-17
10.1017/S1471068413000653
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper explores the contributions of Answer Set Programming (ASP) to the study of an established theory from the field of Second Language Acquisition: Input Processing. The theory describes default strategies that learners of a second language use in extracting meaning out of a text, based on their knowledge of the second language and their background knowledge about the world. We formalized this theory in ASP, and as a result we were able to determine opportunities for refining its natural language description, as well as directions for future theory development. We applied our model to automating the prediction of how learners of English would interpret sentences containing the passive voice. We present a system, PIas, that uses these predictions to assist language instructors in designing teaching materials. To appear in Theory and Practice of Logic Programming (TPLP).
[ { "version": "v1", "created": "Mon, 9 Dec 2013 16:37:22 GMT" } ]
1,582,070,400,000
[ [ "Inclezan", "Daniela", "" ] ]
1312.2709
Anugrah Kumar
Anugrah Kumar, Sanjiban Shekar Roy, Sarvesh SS Rawat, Sanklan Saxena
Phishing Detection by determining reliability factor using rough set theory
The International Conference on Machine Intelligence Research and Advancement, ICMIRA-2013
null
null
null
cs.AI
http://creativecommons.org/licenses/by/3.0/
Phishing is a common online weapon, used against users, by Phishers for acquiring a confidential information through deception. Since the inception of internet, nearly everything, ranging from money transaction to sharing information, is done online in most parts of the world. This has also given rise to malicious activities such as Phishing. Detecting Phishing is an intricate process due to complexity, ambiguity and copious amount of possibilities of factors responsible for phishing . Rough sets can be a powerful tool, when working on such kind of Applications containing vague or imprecise data. This paper proposes an approach towards Phishing Detection Using Rough Set Theory. The Thirteen basic factors, directly responsible towards Phishing, are grouped into four Strata. Reliability Factor is determined on the basis of the outcome of these strata, using Rough Set Theory . Reliability Factor determines the possibility of a suspected site to be Valid or Fake. Using Rough set Theory most and the least influential factors towards Phishing are also determined.
[ { "version": "v1", "created": "Tue, 10 Dec 2013 08:10:38 GMT" } ]
1,386,720,000,000
[ [ "Kumar", "Anugrah", "" ], [ "Roy", "Sanjiban Shekar", "" ], [ "Rawat", "Sarvesh SS", "" ], [ "Saxena", "Sanklan", "" ] ]
1312.2798
Fennie Liang
Shao Fen Liang, Donia Scott, Robert Stevens and Alan Rector
OntoVerbal: a Generic Tool and Practical Application to SNOMED CT
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Ontology development is a non-trivial task requiring expertise in the chosen ontological language. We propose a method for making the content of ontologies more transparent by presenting, through the use of natural language generation, naturalistic descriptions of ontology classes as textual paragraphs. The method has been implemented in a proof-of- concept system, OntoVerbal, that automatically generates paragraph-sized textual descriptions of ontological classes expressed in OWL. OntoVerbal has been applied to ontologies that can be loaded into Prot\'eg\'e and been evaluated with SNOMED CT, showing that it provides coherent, well-structured and accurate textual descriptions of ontology classes.
[ { "version": "v1", "created": "Tue, 10 Dec 2013 13:55:30 GMT" } ]
1,386,720,000,000
[ [ "Liang", "Shao Fen", "" ], [ "Scott", "Donia", "" ], [ "Stevens", "Robert", "" ], [ "Rector", "Alan", "" ] ]
1312.3825
Claas Ahlrichs
Claas Ahlrichs and Michael Lawo
Parkinson's Disease Motor Symptoms in Machine Learning: A Review
Health Informatics: An International Journal (HIIJ), November 2013, Volume 2, Number 4
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper reviews related work and state-of-the-art publications for recognizing motor symptoms of Parkinson's Disease (PD). It presents research efforts that were undertaken to inform on how well traditional machine learning algorithms can handle this task. In particular, four PD related motor symptoms are highlighted (i.e. tremor, bradykinesia, freezing of gait and dyskinesia) and their details summarized. Thus the primary objective of this research is to provide a literary foundation for development and improvement of algorithms for detecting PD related motor symptoms.
[ { "version": "v1", "created": "Fri, 13 Dec 2013 14:58:39 GMT" } ]
1,387,152,000,000
[ [ "Ahlrichs", "Claas", "" ], [ "Lawo", "Michael", "" ] ]
1312.3971
Tommaso Urli
Tommaso Urli
Balancing bike sharing systems (BBSS): instance generation from the CitiBike NYC data
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Bike sharing systems are a very popular means to provide bikes to citizens in a simple and cheap way. The idea is to install bike stations at various points in the city, from which a registered user can easily loan a bike by removing it from a specialized rack. After the ride, the user may return the bike at any station (if there is a free rack). Services of this kind are mainly public or semi-public, often aimed at increasing the attractiveness of non-motorized means of transportation, and are usually free, or almost free, of charge for the users. Depending on their location, bike stations have specific patterns regarding when they are empty or full. For instance, in cities where most jobs are located near the city centre, the commuters cause certain peaks in the morning: the central bike stations are filled, while the stations in the outskirts are emptied. Furthermore, stations located on top of a hill are more likely to be empty, since users are less keen on cycling uphill to return the bike, and often leave their bike at a more reachable station. These issues result in substantial user dissatisfaction which may eventually cause the users to abandon the service. This is why nowadays most bike sharing system providers take measures to rebalance them. Over the last few years, balancing bike sharing systems (BBSS) has become increasingly studied in optimization. As such, generating meaningful instance to serve as a benchmark for the proposed approaches is an important task. In this technical report we describe the procedure we used to generate BBSS problem instances from data of the CitiBike NYC bike sharing system.
[ { "version": "v1", "created": "Fri, 13 Dec 2013 22:10:54 GMT" } ]
1,387,238,400,000
[ [ "Urli", "Tommaso", "" ] ]
1312.4231
Aiping Huang
Aiping Huang and William Zhu
Dependence space of matroids and its application to attribute reduction
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Attribute reduction is a basic issue in knowledge representation and data mining. Rough sets provide a theoretical foundation for the issue. Matroids generalized from matrices have been widely used in many fields, particularly greedy algorithm design, which plays an important role in attribute reduction. Therefore, it is meaningful to combine matroids with rough sets to solve the optimization problems. In this paper, we introduce an existing algebraic structure called dependence space to study the reduction problem in terms of matroids. First, a dependence space of matroids is constructed. Second, the characterizations for the space such as consistent sets and reducts are studied through matroids. Finally, we investigate matroids by the means of the space and present two expressions for their bases. In a word, this paper provides new approaches to study attribute reduction.
[ { "version": "v1", "created": "Mon, 16 Dec 2013 02:27:15 GMT" }, { "version": "v2", "created": "Thu, 5 Mar 2015 02:45:33 GMT" } ]
1,425,600,000,000
[ [ "Huang", "Aiping", "" ], [ "Zhu", "William", "" ] ]
1312.4232
Aiping Huang
Aiping Huang and William Zhu
Geometric lattice structure of covering and its application to attribute reduction through matroids
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The reduction of covering decision systems is an important problem in data mining, and covering-based rough sets serve as an efficient technique to process the problem. Geometric lattices have been widely used in many fields, especially greedy algorithm design which plays an important role in the reduction problems. Therefore, it is meaningful to combine coverings with geometric lattices to solve the optimization problems. In this paper, we obtain geometric lattices from coverings through matroids and then apply them to the issue of attribute reduction. First, a geometric lattice structure of a covering is constructed through transversal matroids. Then its atoms are studied and used to describe the lattice. Second, considering that all the closed sets of a finite matroid form a geometric lattice, we propose a dependence space through matroids and study the attribute reduction issues of the space, which realizes the application of geometric lattices to attribute reduction. Furthermore, a special type of information system is taken as an example to illustrate the application. In a word, this work points out an interesting view, namely, geometric lattice to study the attribute reduction issues of information systems.
[ { "version": "v1", "created": "Mon, 16 Dec 2013 02:30:07 GMT" }, { "version": "v2", "created": "Sat, 4 Jan 2014 11:55:51 GMT" } ]
1,389,052,800,000
[ [ "Huang", "Aiping", "" ], [ "Zhu", "William", "" ] ]
1312.4234
Aiping Huang
Aiping Huang and William Zhu
Connectedness of graphs and its application to connected matroids through covering-based rough sets
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Graph theoretical ideas are highly utilized by computer science fields especially data mining. In this field, a data structure can be designed in the form of tree. Covering is a widely used form of data representation in data mining and covering-based rough sets provide a systematic approach to this type of representation. In this paper, we study the connectedness of graphs through covering-based rough sets and apply it to connected matroids. First, we present an approach to inducing a covering by a graph, and then study the connectedness of the graph from the viewpoint of the covering approximation operators. Second, we construct a graph from a matroid, and find the matroid and the graph have the same connectedness, which makes us to use covering-based rough sets to study connected matroids. In summary, this paper provides a new approach to studying graph theory and matroid theory.
[ { "version": "v1", "created": "Mon, 16 Dec 2013 02:32:43 GMT" }, { "version": "v2", "created": "Sat, 4 Jan 2014 12:00:52 GMT" }, { "version": "v3", "created": "Wed, 4 Mar 2015 08:23:03 GMT" } ]
1,425,513,600,000
[ [ "Huang", "Aiping", "" ], [ "Zhu", "William", "" ] ]
1312.4839
Federico Cerutti
Chatschik Bisdikian, Federico Cerutti, Yuqing Tang, Nir Oren
Reasoning about the Impacts of Information Sharing
Submitted to Information Systems Frontiers Journal
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we describe a decision process framework allowing an agent to decide what information it should reveal to its neighbours within a communication graph in order to maximise its utility. We assume that these neighbours can pass information onto others within the graph. The inferences made by agents receiving the messages can have a positive or negative impact on the information providing agent, and our decision process seeks to identify how a message should be modified in order to be most beneficial to the information producer. Our decision process is based on the provider's subjective beliefs about others in the system, and therefore makes extensive use of the notion of trust. Our core contributions are therefore the construction of a model of information propagation; the description of the agent's decision procedure; and an analysis of some of its properties.
[ { "version": "v1", "created": "Tue, 19 Nov 2013 09:30:23 GMT" } ]
1,387,324,800,000
[ [ "Bisdikian", "Chatschik", "" ], [ "Cerutti", "Federico", "" ], [ "Tang", "Yuqing", "" ], [ "Oren", "Nir", "" ] ]
1312.5097
Alexander Darer
Alexander Darer and Peter Lewis
A Cellular Automaton Based Controller for a Ms. Pac-Man Agent
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Video games can be used as an excellent test bed for Artificial Intelligence (AI) techniques. They are challenging and non-deterministic, this makes it very difficult to write strong AI players. An example of such a video game is Ms. Pac-Man. In this paper we will outline some of the previous techniques used to build AI controllers for Ms. Pac-Man as well as presenting a new and novel solution. My technique utilises a Cellular Automaton (CA) to build a representation of the environment at each time step of the game. The basis of the representation is a 2-D grid of cells. Each cell has a state and a set of rules which determine whether or not that cell will dominate (i.e. pass its state value onto) adjacent cells at each update. Once a certain number of update iterations have been completed, the CA represents the state of the environment in the game, the goals and the dangers. At this point, Ms. Pac-Man will decide her next move based only on her adjacent cells, that is to say, she has no knowledge of the state of the environment as a whole, she will simply follow the strongest path. This technique shows promise and allows the controller to achieve high scores in a live game, the behaviour it exhibits is interesting and complex. Moreover, this behaviour is produced by using very simple rules which are applied many times to each cell in the grid. Simple local interactions with complex global results are truly achieved.
[ { "version": "v1", "created": "Wed, 18 Dec 2013 11:08:05 GMT" } ]
1,387,411,200,000
[ [ "Darer", "Alexander", "" ], [ "Lewis", "Peter", "" ] ]
1312.5162
Leon Abdillah
Ardina Ariani, Leon Andretti Abdillah, Firamon Syakti
Sistem pendukung keputusan kelayakan TKI ke luar negeri menggunakan FMADM
Jurnal Sistem Informasi (SISFO)
Jurnal Sistem Informasi (SISFO), vol. 4, pp. 336-343, September 2013
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
BP3TKI Palembang is the government agencies that coordinate, execute and selection of prospective migrants registration and placement. To simplify the existing procedures and improve decision-making is necessary to build a decision support system (DSS) to determine eligibility for employment abroad by applying Fuzzy Multiple Attribute Decision Making (FMADM), using the linear sequential systems development methods. The system is built using Microsoft Visual Basic. Net 2010 and SQL Server 2008 database. The design of the system using use case diagrams and class diagrams to identify the needs of users and systems as well as systems implementation guidelines. This Decision Support System able to rank and produce the prospective migrants, making it easier for parties to take decision BP3TKI the workers who will be working out of the country.
[ { "version": "v1", "created": "Tue, 17 Dec 2013 16:59:16 GMT" } ]
1,387,411,200,000
[ [ "Ariani", "Ardina", "" ], [ "Abdillah", "Leon Andretti", "" ], [ "Syakti", "Firamon", "" ] ]
1312.5378
Guy Van den Broeck
Guy Van den Broeck, Wannes Meert, Adnan Darwiche
Skolemization for Weighted First-Order Model Counting
To appear in Proceedings of the 14th International Conference on Principles of Knowledge Representation and Reasoning (KR), Vienna, Austria, July 2014
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
First-order model counting emerged recently as a novel reasoning task, at the core of efficient algorithms for probabilistic logics. We present a Skolemization algorithm for model counting problems that eliminates existential quantifiers from a first-order logic theory without changing its weighted model count. For certain subsets of first-order logic, lifted model counters were shown to run in time polynomial in the number of objects in the domain of discourse, where propositional model counters require exponential time. However, these guarantees apply only to Skolem normal form theories (i.e., no existential quantifiers) as the presence of existential quantifiers reduces lifted model counters to propositional ones. Since textbook Skolemization is not sound for model counting, these restrictions precluded efficient model counting for directed models, such as probabilistic logic programs, which rely on existential quantification. Our Skolemization procedure extends the applicability of first-order model counters to these representations. Moreover, it simplifies the design of lifted model counting algorithms.
[ { "version": "v1", "created": "Thu, 19 Dec 2013 00:40:56 GMT" }, { "version": "v2", "created": "Wed, 5 Mar 2014 13:50:15 GMT" } ]
1,394,064,000,000
[ [ "Broeck", "Guy Van den", "" ], [ "Meert", "Wannes", "" ], [ "Darwiche", "Adnan", "" ] ]
1312.5515
Marek Kurdej
Marek Kurdej (HEUDIASYC), V\'eronique Cherfaoui (HEUDIASYC)
Conservative, Proportional and Optimistic Contextual Discounting in the Belief Functions Theory
7 pages
16th International Conference on Information Fusion, Istanbul : Turkey (2013)
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Information discounting plays an important role in the theory of belief functions and, generally, in information fusion. Nevertheless, neither classical uniform discounting nor contextual cannot model certain use cases, notably temporal discounting. In this article, new contextual discounting schemes, conservative, proportional and optimistic, are proposed. Some properties of these discounting operations are examined. Classical discounting is shown to be a special case of these schemes. Two motivating cases are discussed: modelling of source reliability and application to temporal discounting.
[ { "version": "v1", "created": "Thu, 19 Dec 2013 12:40:25 GMT" } ]
1,387,497,600,000
[ [ "Kurdej", "Marek", "", "HEUDIASYC" ], [ "Cherfaoui", "Véronique", "", "HEUDIASYC" ] ]
1312.5713
Dimiter Dobrev
Dimiter Dobrev
Giving the AI definition a form suitable for the engineer
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Artificial Intelligence - what is this? That is the question! In earlier papers we already gave a formal definition for AI, but if one desires to build an actual AI implementation, the following issues require attention and are treated here: the data format to be used, the idea of Undef and Nothing symbols, various ways for defining the "meaning of life", and finally, a new notion of "incorrect move". These questions are of minor importance in the theoretical discussion, but we already know the answer of the question "Does AI exist?" Now we want to make the next step and to create this program.
[ { "version": "v1", "created": "Thu, 19 Dec 2013 19:28:18 GMT" }, { "version": "v2", "created": "Tue, 31 Mar 2015 10:26:48 GMT" } ]
1,427,846,400,000
[ [ "Dobrev", "Dimiter", "" ] ]
1312.5714
Patrick Connor
Patrick C. Connor and Thomas P. Trappenberg
Avoiding Confusion between Predictors and Inhibitors in Value Function Approximation
14 pages, 3 figures, 23 references, Workshop paper in ICLR 2014 (updated based on reviewer comments)
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In reinforcement learning, the goal is to seek rewards and avoid punishments. A simple scalar captures the value of a state or of taking an action, where expected future rewards increase and punishments decrease this quantity. Naturally an agent should learn to predict this quantity to take beneficial actions, and many value function approximators exist for this purpose. In the present work, however, we show how value function approximators can cause confusion between predictors of an outcome of one valence (e.g., a signal of reward) and the inhibitor of the opposite valence (e.g., a signal canceling expectation of punishment). We show this to be a problem for both linear and non-linear value function approximators, especially when the amount of data (or experience) is limited. We propose and evaluate a simple resolution: to instead predict reward and punishment values separately, and rectify and add them to get the value needed for decision making. We evaluate several function approximators in this slightly different value function approximation architecture and show that this approach is able to circumvent the confusion and thereby achieve lower value-prediction errors.
[ { "version": "v1", "created": "Thu, 19 Dec 2013 19:52:52 GMT" }, { "version": "v2", "created": "Wed, 18 Feb 2015 15:35:56 GMT" } ]
1,424,304,000,000
[ [ "Connor", "Patrick C.", "" ], [ "Trappenberg", "Thomas P.", "" ] ]
1312.6096
Michael Fink
Mario Alviano and Wolfgang Faber
Properties of Answer Set Programming with Convex Generalized Atoms
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In recent years, Answer Set Programming (ASP), logic programming under the stable model or answer set semantics, has seen several extensions by generalizing the notion of an atom in these programs: be it aggregate atoms, HEX atoms, generalized quantifiers, or abstract constraints, the idea is to have more complicated satisfaction patterns in the lattice of Herbrand interpretations than traditional, simple atoms. In this paper we refer to any of these constructs as generalized atoms. Several semantics with differing characteristics have been proposed for these extensions, rendering the big picture somewhat blurry. In this paper, we analyze the class of programs that have convex generalized atoms (originally proposed by Liu and Truszczynski in [10]) in rule bodies and show that for this class many of the proposed semantics coincide. This is an interesting result, since recently it has been shown that this class is the precise complexity boundary for the FLP semantics. We investigate whether similar results also hold for other semantics, and discuss the implications of our findings.
[ { "version": "v1", "created": "Fri, 20 Dec 2013 20:18:04 GMT" } ]
1,387,756,800,000
[ [ "Alviano", "Mario", "" ], [ "Faber", "Wolfgang", "" ] ]
1312.6105
Michael Fink
Marcello Balduccini and Yulia Lierler
Hybrid Automated Reasoning Tools: from Black-box to Clear-box Integration
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Recently, researchers in answer set programming and constraint programming spent significant efforts in the development of hybrid languages and solving algorithms combining the strengths of these traditionally separate fields. These efforts resulted in a new research area: constraint answer set programming (CASP). CASP languages and systems proved to be largely successful at providing efficient solutions to problems involving hybrid reasoning tasks, such as scheduling problems with elements of planning. Yet, the development of CASP systems is difficult, requiring non-trivial expertise in multiple areas. This suggests a need for a study identifying general development principles of hybrid systems. Once these principles and their implications are well understood, the development of hybrid languages and systems may become a well-established and well-understood routine process. As a step in this direction, in this paper we conduct a case study aimed at evaluating various integration schemas of CASP methods.
[ { "version": "v1", "created": "Fri, 20 Dec 2013 20:44:58 GMT" } ]
1,387,756,800,000
[ [ "Balduccini", "Marcello", "" ], [ "Lierler", "Yulia", "" ] ]
1312.6113
Michael Fink
Mutsunori Banbara, Martin Gebser, Katsumi Inoue, Torsten Schaub, Takehide Soh, Naoyuki Tamura and Matthias Weise
Aspartame: Solving Constraint Satisfaction Problems with Answer Set Programming
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Encoding finite linear CSPs as Boolean formulas and solving them by using modern SAT solvers has proven to be highly effective, as exemplified by the award-winning sugar system. We here develop an alternative approach based on ASP. This allows us to use first-order encodings providing us with a high degree of flexibility for easy experimentation with different implementations. The resulting system aspartame re-uses parts of sugar for parsing and normalizing CSPs. The obtained set of facts is then combined with an ASP encoding that can be grounded and solved by off-the-shelf ASP systems. We establish the competitiveness of our approach by empirically contrasting aspartame and sugar.
[ { "version": "v1", "created": "Fri, 20 Dec 2013 20:57:28 GMT" } ]
1,387,756,800,000
[ [ "Banbara", "Mutsunori", "" ], [ "Gebser", "Martin", "" ], [ "Inoue", "Katsumi", "" ], [ "Schaub", "Torsten", "" ], [ "Soh", "Takehide", "" ], [ "Tamura", "Naoyuki", "" ], [ "Weise", "Matthias", "" ] ]
1312.6130
Michael Fink
Michael Bartholomew and Joohyung Lee
A Functional View of Strong Negation in Answer Set Programming
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The distinction between strong negation and default negation has been useful in answer set programming. We present an alternative account of strong negation, which lets us view strong negation in terms of the functional stable model semantics by Bartholomew and Lee. More specifically, we show that, under complete interpretations, minimizing both positive and negative literals in the traditional answer set semantics is essentially the same as ensuring the uniqueness of Boolean function values under the functional stable model semantics. The same account lets us view Lifschitz's two-valued logic programs as a special case of the functional stable model semantics. In addition, we show how non-Boolean intensional functions can be eliminated in favor of Boolean intensional functions, and furthermore can be represented using strong negation, which provides a way to compute the functional stable model semantics using existing ASP solvers. We also note that similar results hold with the functional stable model semantics by Cabalar.
[ { "version": "v1", "created": "Fri, 20 Dec 2013 21:01:32 GMT" } ]
1,387,843,200,000
[ [ "Bartholomew", "Michael", "" ], [ "Lee", "Joohyung", "" ] ]
1312.6134
Michael Fink
Pedro Cabalar and Jorge Fandinno
An Algebra of Causal Chains
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this work we propose a multi-valued extension of logic programs under the stable models semantics where each true atom in a model is associated with a set of justifications, in a similar spirit than a set of proof trees. The main contribution of this paper is that we capture justifications into an algebra of truth values with three internal operations: an addition '+' representing alternative justifications for a formula, a commutative product '*' representing joint interaction of causes and a non-commutative product '.' acting as a concatenation or proof constructor. Using this multi-valued semantics, we obtain a one-to-one correspondence between the syntactic proof tree of a standard (non-causal) logic program and the interpretation of each true atom in a model. Furthermore, thanks to this algebraic characterization we can detect semantic properties like redundancy and relevance of the obtained justifications. We also identify a lattice-based characterization of this algebra, defining a direct consequences operator, proving its continuity and that its least fix point can be computed after a finite number of iterations. Finally, we define the concept of causal stable model by introducing an analogous transformation to Gelfond and Lifschitz's program reduct.
[ { "version": "v1", "created": "Fri, 20 Dec 2013 21:07:19 GMT" } ]
1,387,843,200,000
[ [ "Cabalar", "Pedro", "" ], [ "Fandinno", "Jorge", "" ] ]
1312.6138
Michael Fink
Vinay K. Chaudhri, Stijn Heymans, Michael Wessel and Tran Cao Son
Query Answering in Object Oriented Knowledge Bases in Logic Programming: Description and Challenge for ASP
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Research on developing efficient and scalable ASP solvers can substantially benefit by the availability of data sets to experiment with. KB_Bio_101 contains knowledge from a biology textbook, has been developed as part of Project Halo, and has recently become available for research use. KB_Bio_101 is one of the largest KBs available in ASP and the reasoning with it is undecidable in general. We give a description of this KB and ASP programs for a suite of queries that have been of practical interest. We explain why these queries pose significant practical challenges for the current ASP solvers.
[ { "version": "v1", "created": "Fri, 20 Dec 2013 21:13:10 GMT" } ]
1,387,843,200,000
[ [ "Chaudhri", "Vinay K.", "" ], [ "Heymans", "Stijn", "" ], [ "Wessel", "Michael", "" ], [ "Son", "Tran Cao", "" ] ]
1312.6140
Michael Fink
Stefan Ellmauthaler and Hannes Strass
The DIAMOND System for Argumentation: Preliminary Report
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Abstract dialectical frameworks (ADFs) are a powerful generalisation of Dung's abstract argumentation frameworks. In this paper we present an answer set programming based software system, called DIAMOND (DIAlectical MOdels eNcoDing). It translates ADFs into answer set programs whose stable models correspond to models of the ADF with respect to several semantics (i.e. admissible, complete, stable, grounded).
[ { "version": "v1", "created": "Fri, 20 Dec 2013 21:17:03 GMT" } ]
1,387,843,200,000
[ [ "Ellmauthaler", "Stefan", "" ], [ "Strass", "Hannes", "" ] ]
1312.6143
Michael Fink
Martin Gebser, Philipp Obermeier and Torsten Schaub
A System for Interactive Query Answering with Answer Set Programming
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Reactive answer set programming has paved the way for incorporating online information into operative solving processes. Although this technology was originally devised for dealing with data streams in dynamic environments, like assisted living and cognitive robotics, it can likewise be used to incorporate facts, rules, or queries provided by a user. As a result, we present the design and implementation of a system for interactive query answering with reactive answer set programming. Our system quontroller is based on the reactive solver oclingo and implemented as a dedicated front-end. We describe its functionality and implementation, and we illustrate its features by some selected use cases.
[ { "version": "v1", "created": "Fri, 20 Dec 2013 21:24:30 GMT" } ]
1,387,843,200,000
[ [ "Gebser", "Martin", "" ], [ "Obermeier", "Philipp", "" ], [ "Schaub", "Torsten", "" ] ]
1312.6146
Michael Fink
Canan G\"uni\c{c}en, Esra Erdem and H\"usn\"u Yenig\"un
Generating Shortest Synchronizing Sequences using Answer Set Programming
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
For a finite state automaton, a synchronizing sequence is an input sequence that takes all the states to the same state. Checking the existence of a synchronizing sequence and finding a synchronizing sequence, if one exists, can be performed in polynomial time. However, the problem of finding a shortest synchronizing sequence is known to be NP-hard. In this work, the usefulness of Answer Set Programming to solve this optimization problem is investigated, in comparison with brute-force algorithms and SAT-based approaches. Keywords: finite automata, shortest synchronizing sequence, ASP
[ { "version": "v1", "created": "Fri, 20 Dec 2013 21:30:10 GMT" } ]
1,387,843,200,000
[ [ "Güniçen", "Canan", "" ], [ "Erdem", "Esra", "" ], [ "Yenigün", "Hüsnü", "" ] ]
1312.6151
Michael Fink
Yuliya Lierler and Miroslaw Truszczynski
Abstract Modular Systems and Solvers
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Integrating diverse formalisms into modular knowledge representation systems offers increased expressivity, modeling convenience and computational benefits. We introduce concepts of abstract modules and abstract modular systems to study general principles behind the design and analysis of model-finding programs, or solvers, for integrated heterogeneous multi-logic systems. We show how abstract modules and abstract modular systems give rise to transition systems, which are a natural and convenient representation of solvers pioneered by the SAT community. We illustrate our approach by showing how it applies to answer set programming and propositional logic, and to multi-logic systems based on these two formalisms.
[ { "version": "v1", "created": "Fri, 20 Dec 2013 21:37:56 GMT" } ]
1,387,843,200,000
[ [ "Lierler", "Yuliya", "" ], [ "Truszczynski", "Miroslaw", "" ] ]
1312.6156
Michael Fink
Joost Vennekens
Negation in the Head of CP-logic Rules
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
CP-logic is a probabilistic extension of the logic FO(ID). Unlike ASP, both of these logics adhere to a Tarskian informal semantics, in which interpretations represent objective states-of-affairs. In other words, these logics lack the epistemic component of ASP, in which interpretations represent the beliefs or knowledge of a rational agent. Consequently, neither CP-logic nor FO(ID) have the need for two kinds of negations: there is only one negation, and its meaning is that of objective falsehood. Nevertheless, the formal semantics of this objective negation is mathematically more similar to ASP's negation-as-failure than to its classical negation. The reason is that both CP-logic and FO(ID) have a constructive semantics in which all atoms start out as false, and may only become true as the result of a rule application. This paper investigates the possibility of adding the well-known ASP feature of allowing negation in the head of rules to CP-logic. Because CP-logic only has one kind of negation, it is of necessity this ''negation-as-failure like'' negation that will be allowed in the head. We investigate the intuitive meaning of such a construct and the benefits that arise from it.
[ { "version": "v1", "created": "Fri, 20 Dec 2013 21:41:20 GMT" } ]
1,387,843,200,000
[ [ "Vennekens", "Joost", "" ] ]
1312.6558
Indre Zliobaite
Indre Zliobaite, Mykola Pechenizkiy
Predictive User Modeling with Actionable Attributes
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Different machine learning techniques have been proposed and used for modeling individual and group user needs, interests and preferences. In the traditional predictive modeling instances are described by observable variables, called attributes. The goal is to learn a model for predicting the target variable for unseen instances. For example, for marketing purposes a company consider profiling a new user based on her observed web browsing behavior, referral keywords or other relevant information. In many real world applications the values of some attributes are not only observable, but can be actively decided by a decision maker. Furthermore, in some of such applications the decision maker is interested not only to generate accurate predictions, but to maximize the probability of the desired outcome. For example, a direct marketing manager can choose which type of a special offer to send to a client (actionable attribute), hoping that the right choice will result in a positive response with a higher probability. We study how to learn to choose the value of an actionable attribute in order to maximize the probability of a desired outcome in predictive modeling. We emphasize that not all instances are equally sensitive to changes in actions. Accurate choice of an action is critical for those instances, which are on the borderline (e.g. users who do not have a strong opinion one way or the other). We formulate three supervised learning approaches for learning to select the value of an actionable attribute at an instance level. We also introduce a focused training procedure which puts more emphasis on the situations where varying the action is the most likely to take the effect. The proof of concept experimental validation on two real-world case studies in web analytics and e-learning domains highlights the potential of the proposed approaches.
[ { "version": "v1", "created": "Mon, 23 Dec 2013 14:37:44 GMT" } ]
1,387,843,200,000
[ [ "Zliobaite", "Indre", "" ], [ "Pechenizkiy", "Mykola", "" ] ]
1312.6726
Jordi Grau-Moya
Jordi Grau-Moya and Daniel A. Braun
Bounded Rational Decision-Making in Changing Environments
9 pages, 2 figures, NIPS 2013 Workshop on Planning with Information Constraints
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A perfectly rational decision-maker chooses the best action with the highest utility gain from a set of possible actions. The optimality principles that describe such decision processes do not take into account the computational costs of finding the optimal action. Bounded rational decision-making addresses this problem by specifically trading off information-processing costs and expected utility. Interestingly, a similar trade-off between energy and entropy arises when describing changes in thermodynamic systems. This similarity has been recently used to describe bounded rational agents. Crucially, this framework assumes that the environment does not change while the decision-maker is computing the optimal policy. When this requirement is not fulfilled, the decision-maker will suffer inefficiencies in utility, that arise because the current policy is optimal for an environment in the past. Here we borrow concepts from non-equilibrium thermodynamics to quantify these inefficiencies and illustrate with simulations its relationship with computational resources.
[ { "version": "v1", "created": "Tue, 24 Dec 2013 00:22:44 GMT" } ]
1,387,929,600,000
[ [ "Grau-Moya", "Jordi", "" ], [ "Braun", "Daniel A.", "" ] ]
1312.6764
Eric Nivel
E. Nivel, K. R. Th\'orisson, B. R. Steunebrink, H. Dindo, G. Pezzulo, M. Rodriguez, C. Hernandez, D. Ognibene, J. Schmidhuber, R. Sanz, H. P. Helgason, A. Chella and G. K. Jonsson
Bounded Recursive Self-Improvement
null
null
null
RUTR-SCS13006
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We have designed a machine that becomes increasingly better at behaving in underspecified circumstances, in a goal-directed way, on the job, by modeling itself and its environment as experience accumulates. Based on principles of autocatalysis, endogeny, and reflectivity, the work provides an architectural blueprint for constructing systems with high levels of operational autonomy in underspecified circumstances, starting from a small seed. Through value-driven dynamic priority scheduling controlling the parallel execution of a vast number of reasoning threads, the system achieves recursive self-improvement after it leaves the lab, within the boundaries imposed by its designers. A prototype system has been implemented and demonstrated to learn a complex real-world task, real-time multimodal dialogue with humans, by on-line observation. Our work presents solutions to several challenges that must be solved for achieving artificial general intelligence.
[ { "version": "v1", "created": "Tue, 24 Dec 2013 06:17:55 GMT" } ]
1,387,929,600,000
[ [ "Nivel", "E.", "" ], [ "Thórisson", "K. R.", "" ], [ "Steunebrink", "B. R.", "" ], [ "Dindo", "H.", "" ], [ "Pezzulo", "G.", "" ], [ "Rodriguez", "M.", "" ], [ "Hernandez", "C.", "" ], [ "Ognibene", "D.", "" ], [ "Schmidhuber", "J.", "" ], [ "Sanz", "R.", "" ], [ "Helgason", "H. P.", "" ], [ "Chella", "A.", "" ], [ "Jonsson", "G. K.", "" ] ]
1312.6996
Muhammad Rezaul Karim
Muhammad Rezaul Karim
A New Approach to Constraint Weight Learning for Variable Ordering in CSPs
null
Proceedings of the IEEE Congress on Evolutionary Computation (CEC 2014), pp. 2716-2723, Beijing, China, July 6-11, 2014
10.1109/CEC.2014.6900262
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A Constraint Satisfaction Problem (CSP) is a framework used for modeling and solving constrained problems. Tree-search algorithms like backtracking try to construct a solution to a CSP by selecting the variables of the problem one after another. The order in which these algorithm select the variables potentially have significant impact on the search performance. Various heuristics have been proposed for choosing good variable ordering. Many powerful variable ordering heuristics weigh the constraints first and then utilize the weights for selecting good order of the variables. Constraint weighting are basically employed to identify global bottlenecks in a CSP. In this paper, we propose a new approach for learning weights for the constraints using competitive coevolutionary Genetic Algorithm (GA). Weights learned by the coevolutionary GA later help to make better choices for the first few variables in a search. In the competitive coevolutionary GA, constraints and candidate solutions for a CSP evolve together through an inverse fitness interaction process. We have conducted experiments on several random, quasi-random and patterned instances to measure the efficiency of the proposed approach. The results and analysis show that the proposed approach is good at learning weights to distinguish the hard constraints for quasi-random instances and forced satisfiable random instances generated with the Model RB. For other type of instances, RNDI still seems to be the best approach as our experiments show.
[ { "version": "v1", "created": "Wed, 25 Dec 2013 18:15:14 GMT" } ]
1,412,553,600,000
[ [ "Karim", "Muhammad Rezaul", "" ] ]
1312.7326
Hiqmet Kamberaj Dr.
Hiqmet Kamberaj
Replica Exchange using q-Gaussian Swarm Quantum Particle Intelligence Method
10 pages, 5 figures, 1 table
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present a newly developed Replica Exchange algorithm using q -Gaussian Swarm Quantum Particle Optimization (REX@q-GSQPO) method for solving the problem of finding the global optimum. The basis of the algorithm is to run multiple copies of independent swarms at different values of q parameter. Based on an energy criterion, chosen to satisfy the detailed balance, we are swapping the particle coordinates of neighboring swarms at regular iteration intervals. The swarm replicas with high q values are characterized by high diversity of particles allowing escaping local minima faster, while the low q replicas, characterized by low diversity of particles, are used to sample more efficiently the local basins. We compare the new algorithm with the standard Gaussian Swarm Quantum Particle Optimization (GSQPO) and q-Gaussian Swarm Quantum Particle Optimization (q-GSQPO) algorithms, and we found that the new algorithm is more robust in terms of the number of fitness function calls, and more efficient in terms ability convergence to the global minimum. In additional, we also provide a method of optimally allocating the swarm replicas among different q values. Our algorithm is tested for three benchmark functions, which are known to be multimodal problems, at different dimensionalities. In addition, we considered a polyalanine peptide of 12 residues modeled using a G\=o coarse-graining potential energy function.
[ { "version": "v1", "created": "Sun, 17 Nov 2013 12:49:15 GMT" } ]
1,388,361,600,000
[ [ "Kamberaj", "Hiqmet", "" ] ]
1312.7422
Michael Fink
Michael Fink and Yuliya Lierler
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
Proceedings of Answer Set Programming and Other Computing Paradigms (ASPOCP 2013), 6th International Workshop, August 25, 2013, Istanbul, Turkey
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This volume contains the papers presented at the sixth workshop on Answer Set Programming and Other Computing Paradigms (ASPOCP 2013) held on August 25th, 2013 in Istanbul, co-located with the 29th International Conference on Logic Programming (ICLP 2013). It thus continues a series of previous events co-located with ICLP, aiming at facilitating the discussion about crossing the boundaries of current ASP techniques in theory, solving, and applications, in combination with or inspired by other computing paradigms.
[ { "version": "v1", "created": "Sat, 28 Dec 2013 11:08:35 GMT" } ]
1,388,448,000,000
[ [ "Fink", "Michael", "" ], [ "Lierler", "Yuliya", "" ] ]
1312.7740
Reza Mortezapour
Reza Mortezapour, Mehdi Afzali
Assessment of Customer Credit through Combined Clustering of Artificial Neural Networks, Genetics Algorithm and Bayesian Probabilities
5 pages
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Today, with respect to the increasing growth of demand to get credit from the customers of banks and finance and credit institutions, using an effective and efficient method to decrease the risk of non-repayment of credit given is very necessary. Assessment of customers' credit is one of the most important and the most essential duties of banks and institutions, and if an error occurs in this field, it would leads to the great losses for banks and institutions. Thus, using the predicting computer systems has been significantly progressed in recent decades. The data that are provided to the credit institutions' managers help them to make a straight decision for giving the credit or not-giving it. In this paper, we will assess the customer credit through a combined classification using artificial neural networks, genetics algorithm and Bayesian probabilities simultaneously, and the results obtained from three methods mentioned above would be used to achieve an appropriate and final result. We use the K_folds cross validation test in order to assess the method and finally, we compare the proposed method with the methods such as Clustering-Launched Classification (CLC), Support Vector Machine (SVM) as well as GA+SVM where the genetics algorithm has been used to improve them.
[ { "version": "v1", "created": "Mon, 30 Dec 2013 15:31:25 GMT" } ]
1,388,448,000,000
[ [ "Mortezapour", "Reza", "" ], [ "Afzali", "Mehdi", "" ] ]
1401.0245
Sujit Gath
S.J Gath and R.V Kulkarni
A Review: Expert System for Diagnosis of Myocardial Infarction
7 pages. arXiv admin note: text overlap with arXiv:1006.4544 by other authors
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A computer Program Capable of performing at a human-expert level in a narrow problem domain area is called an expert system. Management of uncertainty is an intrinsically important issue in the design of expert systems because much of the information in the knowledge base of a typical expert system is imprecise, incomplete or not totally reliable. In this paper, the author present s the review of past work that has been carried out by various researchers based on development of expert systems for the diagnosis of cardiac disease
[ { "version": "v1", "created": "Wed, 1 Jan 2014 03:59:22 GMT" } ]
1,388,707,200,000
[ [ "Gath", "S. J", "" ], [ "Kulkarni", "R. V", "" ] ]
1401.1247
Guy Van den Broeck
Mathias Niepert and Guy Van den Broeck
Tractability through Exchangeability: A New Perspective on Efficient Probabilistic Inference
In Proceedings of the 28th AAAI Conference on Artificial Intelligence
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Exchangeability is a central notion in statistics and probability theory. The assumption that an infinite sequence of data points is exchangeable is at the core of Bayesian statistics. However, finite exchangeability as a statistical property that renders probabilistic inference tractable is less well-understood. We develop a theory of finite exchangeability and its relation to tractable probabilistic inference. The theory is complementary to that of independence and conditional independence. We show that tractable inference in probabilistic models with high treewidth and millions of variables can be understood using the notion of finite (partial) exchangeability. We also show that existing lifted inference algorithms implicitly utilize a combination of conditional independence and partial exchangeability.
[ { "version": "v1", "created": "Tue, 7 Jan 2014 00:30:25 GMT" }, { "version": "v2", "created": "Tue, 22 Apr 2014 22:21:16 GMT" } ]
1,398,297,600,000
[ [ "Niepert", "Mathias", "" ], [ "Broeck", "Guy Van den", "" ] ]
1401.1533
Devis Pantano
Devis Pantano
Proposta di nuovi strumenti per comprendere come funziona la cognizione (Novel tools to understand how cognition works)
In Italian
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
I think that the main reason why we do not understand the general principles of how knowledge works (and probably also the reason why we have not yet designed and built efficient machines capable of artificial intelligence), is not the excessive complexity of cognitive phenomena, but the lack of the conceptual and methodological tools to properly address the problem. It is like trying to build up Physics without the concept of number, or to understand the origin of species without including the mechanism of natural selection. In this paper I propose some new conceptual and methodological tools, which seem to offer a real opportunity to understand the logic of cognitive processes. I propose a new method to properly treat the concepts of structure and schema, and to perform on them operations of structural analysis. These operations allow to move straightforwardly from concrete to more abstract representations. With these tools I will suggest a definition for the concept of rule, of regularity and of emergent phenomena. From the analysis of some important aspects of the rules, I suggest to distinguish them in operational and associative rules. I propose that associative rules assume a dominant role in cognition. I also propose a definition for the concept of problem. At the end I will briefly illustrate a possible general model for cognitive systems.
[ { "version": "v1", "created": "Tue, 7 Jan 2014 22:38:18 GMT" }, { "version": "v2", "created": "Mon, 27 Jan 2014 22:26:33 GMT" }, { "version": "v3", "created": "Fri, 18 Apr 2014 19:39:37 GMT" } ]
1,398,038,400,000
[ [ "Pantano", "Devis", "" ] ]
1401.1669
J. G. Wolff
J. Gerard Wolff
Smart machines and the SP theory of intelligence
arXiv admin note: substantial text overlap with arXiv:1306.3890
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
These notes describe how the "SP theory of intelligence", and its embodiment in the "SP machine", may help to realise cognitive computing, as described in the book "Smart Machines". In the SP system, information compression and a concept of "multiple alignment" are centre stage. The system is designed to integrate such things as unsupervised learning, pattern recognition, probabilistic reasoning, and more. It may help to overcome the problem of variety in big data, it may serve in pattern recognition and in the unsupervised learning of structure in data, and it may facilitate the management and transmission of big data. There is potential, via information compression, for substantial gains in computational efficiency, especially in the use of energy. The SP system may help to realise data-centric computing, perhaps via a development of Hebb's concept of a "cell assembly", or via the use of light or DNA for the processing of information. It has potential in the management of errors and uncertainty in data, in medical diagnosis, in processing streams of data, and in promoting adaptability in robots.
[ { "version": "v1", "created": "Wed, 8 Jan 2014 11:32:56 GMT" } ]
1,392,854,400,000
[ [ "Wolff", "J. Gerard", "" ] ]
1401.2153
V Karthikeyan VKK
V.Karthikeyan, V.J.Vijayalakshmi and P.Jeyakumar
Ontology - Based Dynamic Business Process Customization
This paper has been withdrawn by the author due to a crucial sign error
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The interaction between business models is used in consumer centric manner instead of using a producer centric approach for customizing the business process in cloud environment. The knowledge based human semantic web is used for customizing the business process It introduces the Human Semantic Web as a conceptual interface, providing human-understandable semantics on top of the ordinary Semantic Web, which provides machine-readable semantics based on RDF in this mismatching is a major problem. To overcome this following technique automatic customization detection is an automated process of detecting possible elements or variables of a business process that needto be especially treated in order to suit the requirement of the other process. To the business processto be customized as the primary business process and those that it collaborates with as secondary business process or SBP Automatic customization enactment is an automated process of taking actions to perform the customization on the PBP according to the detected customization spots and the automatic reasoning on the customization conceptualization knowledge framework. The process of customizing businessprocesses by composite the web pages by using web service.
[ { "version": "v1", "created": "Thu, 9 Jan 2014 08:23:27 GMT" }, { "version": "v2", "created": "Wed, 22 Jan 2014 08:21:00 GMT" }, { "version": "v3", "created": "Thu, 23 Jan 2014 03:39:52 GMT" } ]
1,390,521,600,000
[ [ "Karthikeyan", "V.", "" ], [ "Vijayalakshmi", "V. J.", "" ], [ "Jeyakumar", "P.", "" ] ]
1401.2474
Barry Hurley
Barry Hurley, Serdar Kadioglu, Yuri Malitsky, Barry O'Sullivan
Transformation-based Feature Computation for Algorithm Portfolios
null
null
null
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Instance-specific algorithm configuration and algorithm portfolios have been shown to offer significant improvements over single algorithm approaches in a variety of application domains. In the SAT and CSP domains algorithm portfolios have consistently dominated the main competitions in these fields for the past five years. For a portfolio approach to be effective there are two crucial conditions that must be met. First, there needs to be a collection of complementary solvers with which to make a portfolio. Second, there must be a collection of problem features that can accurately identify structural differences between instances. This paper focuses on the latter issue: feature representation, because, unlike SAT, not every problem has well-studied features. We employ the well-known SATzilla feature set, but compute alternative sets on different SAT encodings of CSPs. We show that regardless of what encoding is used to convert the instances, adequate structural information is maintained to differentiate between problem instances, and that this can be exploited to make an effective portfolio-based CSP solver.
[ { "version": "v1", "created": "Fri, 10 Jan 2014 22:05:39 GMT" } ]
1,389,657,600,000
[ [ "Hurley", "Barry", "" ], [ "Kadioglu", "Serdar", "" ], [ "Malitsky", "Yuri", "" ], [ "O'Sullivan", "Barry", "" ] ]
1401.2483
Andino Maseleno
Andino Maseleno and Md. Mahmud Hasan
Dempster-Shafer Theory for Move Prediction in Start Kicking of The Bicycle Kick of Sepak Takraw Game
Middle-East Journal of Scientific Research, Vol. 16, No. 7, 2013. ISSN 1990-9233, pp. 896 - 903
null
null
null
cs.AI
http://creativecommons.org/licenses/by/3.0/
This paper presents Dempster-Shafer theory for move prediction in start kicking of the bicycle kick of sepak takraw game. Sepak takraw is a highly complex net-barrier kicking sport that involves dazzling displays of quick reflexes, acrobatic twists, turns and swerves of the agile human body movement. A Bicycle kick or Scissor kick is a physical move made by throwing the body up into the air, making a shearing movement with the legs to get one leg in front of the other without holding on to the ground. Specifically, this paper considers bicycle kick of sepak takraw game in start kicking of the ball with uncertainty where player has different awareness regarding the contingencies. We have chosen Dempster-Shafer theory because the advantages of the Dempster-Shafer theory which include the ability to model information in a flexible way without requiring a probability to be assigned to each element in a set, providing a convenient and simple mechanism for combining two or more pieces of evidence under certain conditions, it can model ignorance explicitly, rejection of the law of additivity for belief in disjoint propositions.
[ { "version": "v1", "created": "Fri, 10 Jan 2014 23:48:40 GMT" } ]
1,389,657,600,000
[ [ "Maseleno", "Andino", "" ], [ "Hasan", "Md. Mahmud", "" ] ]
1401.3428
Nicolas Meuleau
Nicolas Meuleau, Emmanuel Benazera, Ronen I. Brafman, Eric A. Hansen, Mausam
A Heuristic Search Approach to Planning with Continuous Resources in Stochastic Domains
null
Journal Of Artificial Intelligence Research, Volume 34, pages 27-59, 2009
10.1613/jair.2529
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We consider the problem of optimal planning in stochastic domains with resource constraints, where the resources are continuous and the choice of action at each step depends on resource availability. We introduce the HAO* algorithm, a generalization of the AO* algorithm that performs search in a hybrid state space that is modeled using both discrete and continuous state variables, where the continuous variables represent monotonic resources. Like other heuristic search algorithms, HAO* leverages knowledge of the start state and an admissible heuristic to focus computational effort on those parts of the state space that could be reached from the start state by following an optimal policy. We show that this approach is especially effective when resource constraints limit how much of the state space is reachable. Experimental results demonstrate its effectiveness in the domain that motivates our research: automated planning for planetary exploration rovers.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 04:46:00 GMT" } ]
1,389,830,400,000
[ [ "Meuleau", "Nicolas", "" ], [ "Benazera", "Emmanuel", "" ], [ "Brafman", "Ronen I.", "" ], [ "Hansen", "Eric A.", "" ], [ "Mausam", "", "" ] ]
1401.3431
James Delgrande
James Delgrande, Yi Jin, Francis Jeffry Pelletier
Compositional Belief Update
null
Journal Of Artificial Intelligence Research, Volume 32, pages 757-791, 2008
10.1613/jair.2539
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we explore a class of belief update operators, in which the definition of the operator is compositional with respect to the sentence to be added. The goal is to provide an update operator that is intuitive, in that its definition is based on a recursive decomposition of the update sentences structure, and that may be reasonably implemented. In addressing update, we first provide a definition phrased in terms of the models of a knowledge base. While this operator satisfies a core group of the benchmark Katsuno-Mendelzon update postulates, not all of the postulates are satisfied. Other Katsuno-Mendelzon postulates can be obtained by suitably restricting the syntactic form of the sentence for update, as we show. In restricting the syntactic form of the sentence for update, we also obtain a hierarchy of update operators with Winsletts standard semantics as the most basic interesting approach captured. We subsequently give an algorithm which captures this approach; in the general case the algorithm is exponential, but with some not-unreasonable assumptions we obtain an algorithm that is linear in the size of the knowledge base. Hence the resulting approach has much better complexity characteristics than other operators in some situations. We also explore other compositional belief change operators: erasure is developed as a dual operator to update; we show that a forget operator is definable in terms of update; and we give a definition of the compositional revision operator. We obtain that compositional revision, under the most natural definition, yields the Satoh revision operator.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 04:48:21 GMT" } ]
1,389,830,400,000
[ [ "Delgrande", "James", "" ], [ "Jin", "Yi", "" ], [ "Pelletier", "Francis Jeffry", "" ] ]
1401.3436
St\'ephane Ross
St\'ephane Ross, Joelle Pineau, S\'ebastien Paquet, Brahim Chaib-draa
Online Planning Algorithms for POMDPs
null
Journal Of Artificial Intelligence Research, Volume 32, pages 663-704, 2008
10.1613/jair.2567
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Partially Observable Markov Decision Processes (POMDPs) provide a rich framework for sequential decision-making under uncertainty in stochastic domains. However, solving a POMDP is often intractable except for small problems due to their complexity. Here, we focus on online approaches that alleviate the computational complexity by computing good local policies at each decision step during the execution. Online algorithms generally consist of a lookahead search to find the best action to execute at each time step in an environment. Our objectives here are to survey the various existing online POMDP methods, analyze their properties and discuss their advantages and disadvantages; and to thoroughly evaluate these online approaches in different environments under various metrics (return, error bound reduction, lower bound improvement). Our experimental results indicate that state-of-the-art online heuristic search methods can handle large POMDP domains efficiently.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 04:52:25 GMT" } ]
1,389,830,400,000
[ [ "Ross", "Stéphane", "" ], [ "Pineau", "Joelle", "" ], [ "Paquet", "Sébastien", "" ], [ "Chaib-draa", "Brahim", "" ] ]
1401.3437
Eyal Amir
Eyal Amir, Allen Chang
Learning Partially Observable Deterministic Action Models
null
Journal Of Artificial Intelligence Research, Volume 33, pages 349-402, 2008
10.1613/jair.2575
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present exact algorithms for identifying deterministic-actions effects and preconditions in dynamic partially observable domains. They apply when one does not know the action model(the way actions affect the world) of a domain and must learn it from partial observations over time. Such scenarios are common in real world applications. They are challenging for AI tasks because traditional domain structures that underly tractability (e.g., conditional independence) fail there (e.g., world features become correlated). Our work departs from traditional assumptions about partial observations and action models. In particular, it focuses on problems in which actions are deterministic of simple logical structure and observation models have all features observed with some frequency. We yield tractable algorithms for the modified problem for such domains. Our algorithms take sequences of partial observations over time as input, and output deterministic action models that could have lead to those observations. The algorithms output all or one of those models (depending on our choice), and are exact in that no model is misclassified given the observations. Our algorithms take polynomial time in the number of time steps and state features for some traditional action classes examined in the AI-planning literature, e.g., STRIPS actions. In contrast, traditional approaches for HMMs and Reinforcement Learning are inexact and exponentially intractable for such domains. Our experiments verify the theoretical tractability guarantees, and show that we identify action models exactly. Several applications in planning, autonomous exploration, and adventure-game playing already use these results. They are also promising for probabilistic settings, partially observable reinforcement learning, and diagnosis.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 04:52:56 GMT" } ]
1,389,830,400,000
[ [ "Amir", "Eyal", "" ], [ "Chang", "Allen", "" ] ]
1401.3438
Neil C.A. Moore
Neil C.A. Moore, Patrick Prosser
The Ultrametric Constraint and its Application to Phylogenetics
null
Journal Of Artificial Intelligence Research, Volume 32, pages 901-938, 2008
10.1613/jair.2580
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A phylogenetic tree shows the evolutionary relationships among species. Internal nodes of the tree represent speciation events and leaf nodes correspond to species. A goal of phylogenetics is to combine such trees into larger trees, called supertrees, whilst respecting the relationships in the original trees. A rooted tree exhibits an ultrametric property; that is, for any three leaves of the tree it must be that one pair has a deeper most recent common ancestor than the other pairs, or that all three have the same most recent common ancestor. This inspires a constraint programming encoding for rooted trees. We present an efficient constraint that enforces the ultrametric property over a symmetric array of constrained integer variables, with the inevitable property that the lower bounds of any three variables are mutually supportive. We show that this allows an efficient constraint-based solution to the supertree construction problem. We demonstrate that the versatility of constraint programming can be exploited to allow solutions to variants of the supertree construction problem.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 04:53:22 GMT" } ]
1,389,830,400,000
[ [ "Moore", "Neil C. A.", "" ], [ "Prosser", "Patrick", "" ] ]
1401.3439
Sonia Chernova
Sonia Chernova, Manuela Veloso
Interactive Policy Learning through Confidence-Based Autonomy
null
Journal Of Artificial Intelligence Research, Volume 34, pages 1-25, 2009
10.1613/jair.2584
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We present Confidence-Based Autonomy (CBA), an interactive algorithm for policy learning from demonstration. The CBA algorithm consists of two components which take advantage of the complimentary abilities of humans and computer agents. The first component, Confident Execution, enables the agent to identify states in which demonstration is required, to request a demonstration from the human teacher and to learn a policy based on the acquired data. The algorithm selects demonstrations based on a measure of action selection confidence, and our results show that using Confident Execution the agent requires fewer demonstrations to learn the policy than when demonstrations are selected by a human teacher. The second algorithmic component, Corrective Demonstration, enables the teacher to correct any mistakes made by the agent through additional demonstrations in order to improve the policy and future task performance. CBA and its individual components are compared and evaluated in a complex simulated driving domain. The complete CBA algorithm results in the best overall learning performance, successfully reproducing the behavior of the teacher while balancing the tradeoff between number of demonstrations and number of incorrect actions during learning.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 04:53:48 GMT" } ]
1,389,830,400,000
[ [ "Chernova", "Sonia", "" ], [ "Veloso", "Manuela", "" ] ]
1401.3442
Amir Gershman
Amir Gershman, Amnon Meisels, Roie Zivan
Asynchronous Forward Bounding for Distributed COPs
null
Journal Of Artificial Intelligence Research, Volume 34, pages 61-88, 2009
10.1613/jair.2591
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A new search algorithm for solving distributed constraint optimization problems (DisCOPs) is presented. Agents assign variables sequentially and compute bounds on partial assignments asynchronously. The asynchronous bounds computation is based on the propagation of partial assignments. The asynchronous forward-bounding algorithm (AFB) is a distributed optimization search algorithm that keeps one consistent partial assignment at all times. The algorithm is described in detail and its correctness proven. Experimental evaluation shows that AFB outperforms synchronous branch and bound by many orders of magnitude, and produces a phase transition as the tightness of the problem increases. This is an analogous effect to the phase transition that has been observed when local consistency maintenance is applied to MaxCSPs. The AFB algorithm is further enhanced by the addition of a backjumping mechanism, resulting in the AFB-BJ algorithm. Distributed backjumping is based on accumulated information on bounds of all values and on processing concurrently a queue of candidate goals for the next move back. The AFB-BJ algorithm is compared experimentally to other DisCOP algorithms (ADOPT, DPOP, OptAPO) and is shown to be a very efficient algorithm for DisCOPs.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 04:54:38 GMT" } ]
1,389,830,400,000
[ [ "Gershman", "Amir", "" ], [ "Meisels", "Amnon", "" ], [ "Zivan", "Roie", "" ] ]
1401.3443
Antonis Kakas
Antonis Kakas, Paolo Mancarella, Fariba Sadri, Kostas Stathis, Francesca Toni
Computational Logic Foundations of KGP Agents
null
Journal Of Artificial Intelligence Research, Volume 33, pages 285-348, 2008
10.1613/jair.2596
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents the computational logic foundations of a model of agency called the KGP (Knowledge, Goals and Plan model. This model allows the specification of heterogeneous agents that can interact with each other, and can exhibit both proactive and reactive behaviour allowing them to function in dynamic environments by adjusting their goals and plans when changes happen in such environments. KGP provides a highly modular agent architecture that integrates a collection of reasoning and physical capabilities, synthesised within transitions that update the agents state in response to reasoning, sensing and acting. Transitions are orchestrated by cycle theories that specify the order in which transitions are executed while taking into account the dynamic context and agent preferences, as well as selection operators for providing inputs to transitions.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 04:54:59 GMT" } ]
1,389,830,400,000
[ [ "Kakas", "Antonis", "" ], [ "Mancarella", "Paolo", "" ], [ "Sadri", "Fariba", "" ], [ "Stathis", "Kostas", "" ], [ "Toni", "Francesca", "" ] ]
1401.3444
Didier Dubois
Didier Dubois, H\'el\`ene Fargier, Jean-Fran\c{c}ois Bonnefon
On the Qualitative Comparison of Decisions Having Positive and Negative Features
null
Journal Of Artificial Intelligence Research, Volume 32, pages 385-417, 2008
10.1613/jair.2520
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Making a decision is often a matter of listing and comparing positive and negative arguments. In such cases, the evaluation scale for decisions should be considered bipolar, that is, negative and positive values should be explicitly distinguished. That is what is done, for example, in Cumulative Prospect Theory. However, contraryto the latter framework that presupposes genuine numerical assessments, human agents often decide on the basis of an ordinal ranking of the pros and the cons, and by focusing on the most salient arguments. In other terms, the decision process is qualitative as well as bipolar. In this article, based on a bipolar extension of possibility theory, we define and axiomatically characterize several decision rules tailored for the joint handling of positive and negative arguments in an ordinal setting. The simplest rules can be viewed as extensions of the maximin and maximax criteria to the bipolar case, and consequently suffer from poor decisive power. More decisive rules that refine the former are also proposed. These refinements agree both with principles of efficiency and with the spirit of order-of-magnitude reasoning, that prevails in qualitative decision theory. The most refined decision rule uses leximin rankings of the pros and the cons, and the ideas of counting arguments of equal strength and cancelling pros by cons. It is shown to come down to a special case of Cumulative Prospect Theory, and to subsume the Take the Best heuristic studied by cognitive psychologists.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 04:55:20 GMT" } ]
1,389,830,400,000
[ [ "Dubois", "Didier", "" ], [ "Fargier", "Hélène", "" ], [ "Bonnefon", "Jean-François", "" ] ]
1401.3448
Robert Mateescu
Robert Mateescu, Rina Dechter, Radu Marinescu
AND/OR Multi-Valued Decision Diagrams (AOMDDs) for Graphical Models
null
Journal Of Artificial Intelligence Research, Volume 33, pages 465-519, 2008
10.1613/jair.2605
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inspired by the recently introduced framework of AND/OR search spaces for graphical models, we propose to augment Multi-Valued Decision Diagrams (MDD) with AND nodes, in order to capture function decomposition structure and to extend these compiled data structures to general weighted graphical models (e.g., probabilistic models). We present the AND/OR Multi-Valued Decision Diagram (AOMDD) which compiles a graphical model into a canonical form that supports polynomial (e.g., solution counting, belief updating) or constant time (e.g. equivalence of graphical models) queries. We provide two algorithms for compiling the AOMDD of a graphical model. The first is search-based, and works by applying reduction rules to the trace of the memory intensive AND/OR search algorithm. The second is inference-based and uses a Bucket Elimination schedule to combine the AOMDDs of the input functions via the the APPLY operator. For both algorithms, the compilation time and the size of the AOMDD are, in the worst case, exponential in the treewidth of the graphical model, rather than pathwidth as is known for ordered binary decision diagrams (OBDDs). We introduce the concept of semantic treewidth, which helps explain why the size of a decision diagram is often much smaller than the worst case bound. We provide an experimental evaluation that demonstrates the potential of AOMDDs.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:09:35 GMT" } ]
1,389,830,400,000
[ [ "Mateescu", "Robert", "" ], [ "Dechter", "Rina", "" ], [ "Marinescu", "Radu", "" ] ]
1401.3450
Tal Grinshpoun
Tal Grinshpoun, Amnon Meisels
Completeness and Performance Of The APO Algorithm
arXiv admin note: substantial text overlap with arXiv:1109.6052 by other authors
Journal Of Artificial Intelligence Research, Volume 33, pages 223-258, 2008
10.1613/jair.2611
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Asynchronous Partial Overlay (APO) is a search algorithm that uses cooperative mediation to solve Distributed Constraint Satisfaction Problems (DisCSPs). The algorithm partitions the search into different subproblems of the DisCSP. The original proof of completeness of the APO algorithm is based on the growth of the size of the subproblems. The present paper demonstrates that this expected growth of subproblems does not occur in some situations, leading to a termination problem of the algorithm. The problematic parts in the APO algorithm that interfere with its completeness are identified and necessary modifications to the algorithm that fix these problematic parts are given. The resulting version of the algorithm, Complete Asynchronous Partial Overlay (CompAPO), ensures its completeness. Formal proofs for the soundness and completeness of CompAPO are given. A detailed performance evaluation of CompAPO comparing it to other DisCSP algorithms is presented, along with an extensive experimental evaluation of the algorithm's unique behavior. Additionally, an optimization version of the algorithm, CompOptAPO, is presented, discussed, and evaluated.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:10:44 GMT" } ]
1,389,830,400,000
[ [ "Grinshpoun", "Tal", "" ], [ "Meisels", "Amnon", "" ] ]
1401.3453
Judy Goldsmith
Judy Goldsmith, Jerome Lang, Miroslaw Truszczyski, Nic Wilson
The Computational Complexity of Dominance and Consistency in CP-Nets
null
Journal Of Artificial Intelligence Research, Volume 33, pages 403-432, 2008
10.1613/jair.2627
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We investigate the computational complexity of testing dominance and consistency in CP-nets. Previously, the complexity of dominance has been determined for restricted classes in which the dependency graph of the CP-net is acyclic. However, there are preferences of interest that define cyclic dependency graphs; these are modeled with general CP-nets. In our main results, we show here that both dominance and consistency for general CP-nets are PSPACE-complete. We then consider the concept of strong dominance, dominance equivalence and dominance incomparability, and several notions of optimality, and identify the complexity of the corresponding decision problems. The reductions used in the proofs are from STRIPS planning, and thus reinforce the earlier established connections between both areas.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:13:25 GMT" } ]
1,389,830,400,000
[ [ "Goldsmith", "Judy", "" ], [ "Lang", "Jerome", "" ], [ "Truszczyski", "Miroslaw", "" ], [ "Wilson", "Nic", "" ] ]
1401.3455
Prashant Doshi
Prashant Doshi, Piotr J. Gmytrasiewicz
Monte Carlo Sampling Methods for Approximating Interactive POMDPs
null
Journal Of Artificial Intelligence Research, Volume 34, pages 297-337, 2009
10.1613/jair.2630
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Partially observable Markov decision processes (POMDPs) provide a principled framework for sequential planning in uncertain single agent settings. An extension of POMDPs to multiagent settings, called interactive POMDPs (I-POMDPs), replaces POMDP belief spaces with interactive hierarchical belief systems which represent an agent's belief about the physical world, about beliefs of other agents, and about their beliefs about others' beliefs. This modification makes the difficulties of obtaining solutions due to complexity of the belief and policy spaces even more acute. We describe a general method for obtaining approximate solutions of I-POMDPs based on particle filtering (PF). We introduce the interactive PF, which descends the levels of the interactive belief hierarchies and samples and propagates beliefs at each level. The interactive PF is able to mitigate the belief space complexity, but it does not address the policy space complexity. To mitigate the policy space complexity -- sometimes also called the curse of history -- we utilize a complementary method based on sampling likely observations while building the look ahead reachability tree. While this approach does not completely address the curse of history, it beats back the curse's impact substantially. We provide experimental results and chart future work.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:14:08 GMT" } ]
1,389,830,400,000
[ [ "Doshi", "Prashant", "" ], [ "Gmytrasiewicz", "Piotr J.", "" ] ]
1401.3458
Fahiem Bacchus
Fahiem Bacchus, Shannon Dalmao, Toniann Pitassi
Solving #SAT and Bayesian Inference with Backtracking Search
null
Journal Of Artificial Intelligence Research, Volume 34, pages 391-442, 2009
10.1613/jair.2648
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Inference in Bayes Nets (BAYES) is an important problem with numerous applications in probabilistic reasoning. Counting the number of satisfying assignments of a propositional formula (#SAT) is a closely related problem of fundamental theoretical importance. Both these problems, and others, are members of the class of sum-of-products (SUMPROD) problems. In this paper we show that standard backtracking search when augmented with a simple memoization scheme (caching) can solve any sum-of-products problem with time complexity that is at least as good any other state-of-the-art exact algorithm, and that it can also achieve the best known time-space tradeoff. Furthermore, backtracking's ability to utilize more flexible variable orderings allows us to prove that it can achieve an exponential speedup over other standard algorithms for SUMPROD on some instances. The ideas presented here have been utilized in a number of solvers that have been applied to various types of sum-of-product problems. These system's have exploited the fact that backtracking can naturally exploit more of the problem's structure to achieve improved performance on a range of probleminstances. Empirical evidence of this performance gain has appeared in published works describing these solvers, and we provide references to these works.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:17:49 GMT" } ]
1,389,830,400,000
[ [ "Bacchus", "Fahiem", "" ], [ "Dalmao", "Shannon", "" ], [ "Pitassi", "Toniann", "" ] ]
1401.3459
Maxim Binshtok
Maxim Binshtok, Ronen I. Brafman, Carmel Domshlak, Solomon Eyal Shimony
Generic Preferences over Subsets of Structured Objects
null
Journal Of Artificial Intelligence Research, Volume 34, pages 133-164, 2009
10.1613/jair.2653
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Various tasks in decision making and decision support systems require selecting a preferred subset of a given set of items. Here we focus on problems where the individual items are described using a set of characterizing attributes, and a generic preference specification is required, that is, a specification that can work with an arbitrary set of items. For example, preferences over the content of an online newspaper should have this form: At each viewing, the newspaper contains a subset of the set of articles currently available. Our preference specification over this subset should be provided offline, but we should be able to use it to select a subset of any currently available set of articles, e.g., based on their tags. We present a general approach for lifting formalisms for specifying preferences over objects with multiple attributes into ones that specify preferences over subsets of such objects. We also show how we can compute an optimal subset given such a specification in a relatively efficient manner. We provide an empirical evaluation of the approach as well as some worst-case complexity results.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:18:50 GMT" } ]
1,389,830,400,000
[ [ "Binshtok", "Maxim", "" ], [ "Brafman", "Ronen I.", "" ], [ "Domshlak", "Carmel", "" ], [ "Shimony", "Solomon Eyal", "" ] ]
1401.3460
Daniel S. Bernstein
Daniel S. Bernstein, Christopher Amato, Eric A. Hansen, Shlomo Zilberstein
Policy Iteration for Decentralized Control of Markov Decision Processes
null
Journal Of Artificial Intelligence Research, Volume 34, pages 89-132, 2009
10.1613/jair.2667
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Coordination of distributed agents is required for problems arising in many areas, including multi-robot systems, networking and e-commerce. As a formal framework for such problems, we use the decentralized partially observable Markov decision process (DEC-POMDP). Though much work has been done on optimal dynamic programming algorithms for the single-agent version of the problem, optimal algorithms for the multiagent case have been elusive. The main contribution of this paper is an optimal policy iteration algorithm for solving DEC-POMDPs. The algorithm uses stochastic finite-state controllers to represent policies. The solution can include a correlation device, which allows agents to correlate their actions without communicating. This approach alternates between expanding the controller and performing value-preserving transformations, which modify the controller without sacrificing value. We present two efficient value-preserving transformations: one can reduce the size of the controller and the other can improve its value while keeping the size fixed. Empirical results demonstrate the usefulness of value-preserving transformations in increasing value while keeping controller size to a minimum. To broaden the applicability of the approach, we also present a heuristic version of the policy iteration algorithm, which sacrifices convergence to optimality. This algorithm further reduces the size of the controllers at each step by assuming that probability distributions over the other agents actions are known. While this assumption may not hold in general, it helps produce higher quality solutions in our test problems.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:20:25 GMT" } ]
1,389,830,400,000
[ [ "Bernstein", "Daniel S.", "" ], [ "Amato", "Christopher", "" ], [ "Hansen", "Eric A.", "" ], [ "Zilberstein", "Shlomo", "" ] ]
1401.3461
Marek Petrik
Marek Petrik, Shlomo Zilberstein
A Bilinear Programming Approach for Multiagent Planning
null
Journal Of Artificial Intelligence Research, Volume 35, pages 235-274, 2009
10.1613/jair.2673
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Multiagent planning and coordination problems are common and known to be computationally hard. We show that a wide range of two-agent problems can be formulated as bilinear programs. We present a successive approximation algorithm that significantly outperforms the coverage set algorithm, which is the state-of-the-art method for this class of multiagent problems. Because the algorithm is formulated for bilinear programs, it is more general and simpler to implement. The new algorithm can be terminated at any time and-unlike the coverage set algorithm-it facilitates the derivation of a useful online performance bound. It is also much more efficient, on average reducing the computation time of the optimal solution by about four orders of magnitude. Finally, we introduce an automatic dimensionality reduction method that improves the effectiveness of the algorithm, extending its applicability to new domains and providing a new way to analyze a subclass of bilinear programs.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:21:26 GMT" } ]
1,389,830,400,000
[ [ "Petrik", "Marek", "" ], [ "Zilberstein", "Shlomo", "" ] ]
1401.3468
Hector Geffner
Hector Palacios, Hector Geffner
Compiling Uncertainty Away in Conformant Planning Problems with Bounded Width
null
Journal Of Artificial Intelligence Research, Volume 35, pages 623-675, 2009
10.1613/jair.2708
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Conformant planning is the problem of finding a sequence of actions for achieving a goal in the presence of uncertainty in the initial state or action effects. The problem has been approached as a path-finding problem in belief space where good belief representations and heuristics are critical for scaling up. In this work, a different formulation is introduced for conformant problems with deterministic actions where they are automatically converted into classical ones and solved by an off-the-shelf classical planner. The translation maps literals L and sets of assumptions t about the initial situation, into new literals KL/t that represent that L must be true if t is initially true. We lay out a general translation scheme that is sound and establish the conditions under which the translation is also complete. We show that the complexity of the complete translation is exponential in a parameter of the problem called the conformant width, which for most benchmarks is bounded. The planner based on this translation exhibits good performance in comparison with existing planners, and is the basis for T0, the best performing planner in the Conformant Track of the 2006 International Planning Competition.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:27:00 GMT" } ]
1,389,830,400,000
[ [ "Palacios", "Hector", "" ], [ "Geffner", "Hector", "" ] ]
1401.3469
Vicente Ruiz de Angulo
Vicente Ruiz de Angulo, Carme Torras
Exploiting Single-Cycle Symmetries in Continuous Constraint Problems
null
Journal Of Artificial Intelligence Research, Volume 34, pages 499-520, 2009
10.1613/jair.2711
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Symmetries in discrete constraint satisfaction problems have been explored and exploited in the last years, but symmetries in continuous constraint problems have not received the same attention. Here we focus on permutations of the variables consisting of one single cycle. We propose a procedure that takes advantage of these symmetries by interacting with a continuous constraint solver without interfering with it. A key concept in this procedure are the classes of symmetric boxes formed by bisecting a n-dimensional cube at the same point in all dimensions at the same time. We analyze these classes and quantify them as a function of the cube dimensionality. Moreover, we propose a simple algorithm to generate the representatives of all these classes for any number of variables at very high rates. A problem example from the chemical and#64257;eld and the cyclic n-roots problem are used to show the performance of the approach in practice.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:27:27 GMT" } ]
1,389,830,400,000
[ [ "de Angulo", "Vicente Ruiz", "" ], [ "Torras", "Carme", "" ] ]
1401.3470
J\"org Hoffmann
J\"org Hoffmann, Piergiorgio Bertoli, Malte Helmert, Marco Pistore
Message-Based Web Service Composition, Integrity Constraints, and Planning under Uncertainty: A New Connection
null
Journal Of Artificial Intelligence Research, Volume 35, pages 49-117, 2009
10.1613/jair.2716
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Thanks to recent advances, AI Planning has become the underlying technique for several applications. Figuring prominently among these is automated Web Service Composition (WSC) at the "capability" level, where services are described in terms of preconditions and effects over ontological concepts. A key issue in addressing WSC as planning is that ontologies are not only formal vocabularies; they also axiomatize the possible relationships between concepts. Such axioms correspond to what has been termed "integrity constraints" in the actions and change literature, and applying a web service is essentially a belief update operation. The reasoning required for belief update is known to be harder than reasoning in the ontology itself. The support for belief update is severely limited in current planning tools. Our first contribution consists in identifying an interesting special case of WSC which is both significant and more tractable. The special case, which we term "forward effects", is characterized by the fact that every ramification of a web service application involves at least one new constant generated as output by the web service. We show that, in this setting, the reasoning required for belief update simplifies to standard reasoning in the ontology itself. This relates to, and extends, current notions of "message-based" WSC, where the need for belief update is removed by a strong (often implicit or informal) assumption of "locality" of the individual messages. We clarify the computational properties of the forward effects case, and point out a strong relation to standard notions of planning under uncertainty, suggesting that effective tools for the latter can be successfully adapted to address the former. Furthermore, we identify a significant sub-case, named "strictly forward effects", where an actual compilation into planning under uncertainty exists. This enables us to exploit off-the-shelf planning tools to solve message-based WSC in a general form that involves powerful ontologies, and requires reasoning about partial matches between concepts. We provide empirical evidence that this approach may be quite effective, using Conformant-FF as the underlying planner.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:27:56 GMT" } ]
1,389,830,400,000
[ [ "Hoffmann", "Jörg", "" ], [ "Bertoli", "Piergiorgio", "" ], [ "Helmert", "Malte", "" ], [ "Pistore", "Marco", "" ] ]
1401.3471
Marco Zaffalon
Marco Zaffalon, Enrique Miranda
Conservative Inference Rule for Uncertain Reasoning under Incompleteness
null
Journal Of Artificial Intelligence Research, Volume 34, pages 757-821, 2009
10.1613/jair.2736
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper we formulate the problem of inference under incomplete information in very general terms. This includes modelling the process responsible for the incompleteness, which we call the incompleteness process. We allow the process behaviour to be partly unknown. Then we use Walleys theory of coherent lower previsions, a generalisation of the Bayesian theory to imprecision, to derive the rule to update beliefs under incompleteness that logically follows from our assumptions, and that we call conservative inference rule. This rule has some remarkable properties: it is an abstract rule to update beliefs that can be applied in any situation or domain; it gives us the opportunity to be neither too optimistic nor too pessimistic about the incompleteness process, which is a necessary condition to draw reliable while strong enough conclusions; and it is a coherent rule, in the sense that it cannot lead to inconsistencies. We give examples to show how the new rule can be applied in expert systems, in parametric statistical inference, and in pattern classification, and discuss more generally the view of incompleteness processes defended here as well as some of its consequences.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:28:54 GMT" } ]
1,389,830,400,000
[ [ "Zaffalon", "Marco", "" ], [ "Miranda", "Enrique", "" ] ]
1401.3474
Andreas Krause
Andreas Krause, Carlos Guestrin
Optimal Value of Information in Graphical Models
null
Journal Of Artificial Intelligence Research, Volume 35, pages 557-591, 2009
10.1613/jair.2737
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Many real-world decision making tasks require us to choose among several expensive observations. In a sensor network, for example, it is important to select the subset of sensors that is expected to provide the strongest reduction in uncertainty. In medical decision making tasks, one needs to select which tests to administer before deciding on the most effective treatment. It has been general practice to use heuristic-guided procedures for selecting observations. In this paper, we present the first efficient optimal algorithms for selecting observations for a class of probabilistic graphical models. For example, our algorithms allow to optimally label hidden variables in Hidden Markov Models (HMMs). We provide results for both selecting the optimal subset of observations, and for obtaining an optimal conditional observation plan. Furthermore we prove a surprising result: In most graphical models tasks, if one designs an efficient algorithm for chain graphs, such as HMMs, this procedure can be generalized to polytree graphical models. We prove that the optimizing value of information is $NP^{PP}$-hard even for polytrees. It also follows from our results that just computing decision theoretic value of information objective functions, which are commonly used in practice, is a #P-complete problem even on Naive Bayes models (a simple special case of polytrees). In addition, we consider several extensions, such as using our algorithms for scheduling observation selection for multiple sensors. We demonstrate the effectiveness of our approach on several real-world datasets, including a prototype sensor network deployment for energy conservation in buildings.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:30:52 GMT" } ]
1,389,830,400,000
[ [ "Krause", "Andreas", "" ], [ "Guestrin", "Carlos", "" ] ]
1401.3477
Jos\'e Enrique Gallardo
Jos\'e Enrique Gallardo, Carlos Cotta, Antonio Jos\'e Fern\'andez
Solving Weighted Constraint Satisfaction Problems with Memetic/Exact Hybrid Algorithms
arXiv admin note: substantial text overlap with arXiv:0812.4170
Journal Of Artificial Intelligence Research, Volume 35, pages 533-555, 2009
10.1613/jair.2770
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
A weighted constraint satisfaction problem (WCSP) is a constraint satisfaction problem in which preferences among solutions can be expressed. Bucket elimination is a complete technique commonly used to solve this kind of constraint satisfaction problem. When the memory required to apply bucket elimination is too high, a heuristic method based on it (denominated mini-buckets) can be used to calculate bounds for the optimal solution. Nevertheless, the curse of dimensionality makes these techniques impractical on large scale problems. In response to this situation, we present a memetic algorithm for WCSPs in which bucket elimination is used as a mechanism for recombining solutions, providing the best possible child from the parental set. Subsequently, a multi-level model in which this exact/metaheuristic hybrid is further hybridized with branch-and-bound techniques and mini-buckets is studied. As a case study, we have applied these algorithms to the resolution of the maximum density still life problem, a hard constraint optimization problem based on Conways game of life. The resulting algorithm consistently finds optimal patterns for up to date solved instances in less time than current approaches. Moreover, it is shown that this proposal provides new best known solutions for very large instances.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:32:38 GMT" } ]
1,389,830,400,000
[ [ "Gallardo", "José Enrique", "" ], [ "Cotta", "Carlos", "" ], [ "Fernández", "Antonio José", "" ] ]
1401.3481
Matthias Zytnicki
Matthias Zytnicki, Christine Gaspin, Simon de Givry, Thomas Schiex
Bounds Arc Consistency for Weighted CSPs
null
Journal Of Artificial Intelligence Research, Volume 35, pages 593-621, 2009
10.1613/jair.2797
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Weighted Constraint Satisfaction Problem (WCSP) framework allows representing and solving problems involving both hard constraints and cost functions. It has been applied to various problems, including resource allocation, bioinformatics, scheduling, etc. To solve such problems, solvers usually rely on branch-and-bound algorithms equipped with local consistency filtering, mostly soft arc consistency. However, these techniques are not well suited to solve problems with very large domains. Motivated by the resolution of an RNA gene localization problem inside large genomic sequences, and in the spirit of bounds consistency for large domains in crisp CSPs, we introduce soft bounds arc consistency, a new weighted local consistency specifically designed for WCSP with very large domains. Compared to soft arc consistency, BAC provides significantly improved time and space asymptotic complexity. In this paper, we show how the semantics of cost functions can be exploited to further improve the time complexity of BAC. We also compare both in theory and in practice the efficiency of BAC on a WCSP with bounds consistency enforced on a crisp CSP using cost variables. On two different real problems modeled as WCSP, including our RNA gene localization problem, we observe that maintaining bounds arc consistency outperforms arc consistency and also improves over bounds consistency enforced on a constraint model with cost variables.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:34:30 GMT" } ]
1,389,830,400,000
[ [ "Zytnicki", "Matthias", "" ], [ "Gaspin", "Christine", "" ], [ "de Givry", "Simon", "" ], [ "Schiex", "Thomas", "" ] ]
1401.3483
Hai Leong Chieu
Hai Leong Chieu, Wee Sun Sun Lee
Relaxed Survey Propagation for The Weighted Maximum Satisfiability Problem
null
Journal Of Artificial Intelligence Research, Volume 36, pages 229-266, 2009
10.1613/jair.2808
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The survey propagation (SP) algorithm has been shown to work well on large instances of the random 3-SAT problem near its phase transition. It was shown that SP estimates marginals over covers that represent clusters of solutions. The SP-y algorithm generalizes SP to work on the maximum satisfiability (Max-SAT) problem, but the cover interpretation of SP does not generalize to SP-y. In this paper, we formulate the relaxed survey propagation (RSP) algorithm, which extends the SP algorithm to apply to the weighted Max-SAT problem. We show that RSP has an interpretation of estimating marginals over covers violating a set of clauses with minimal weight. This naturally generalizes the cover interpretation of SP. Empirically, we show that RSP outperforms SP-y and other state-of-the-art Max-SAT solvers on random Max-SAT instances. RSP also outperforms state-of-the-art weighted Max-SAT solvers on random weighted Max-SAT instances.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:36:10 GMT" } ]
1,389,830,400,000
[ [ "Chieu", "Hai Leong", "" ], [ "Lee", "Wee Sun Sun", "" ] ]
1401.3486
Anders Jonsson
Anders Jonsson
The Role of Macros in Tractable Planning
null
Journal Of Artificial Intelligence Research, Volume 36, pages 471-511, 2009
10.1613/jair.2891
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
This paper presents several new tractability results for planning based on macros. We describe an algorithm that optimally solves planning problems in a class that we call inverted tree reducible, and is provably tractable for several subclasses of this class. By using macros to store partial plans that recur frequently in the solution, the algorithm is polynomial in time and space even for exponentially long plans. We generalize the inverted tree reducible class in several ways and describe modifications of the algorithm to deal with these new classes. Theoretical results are validated in experiments.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:37:49 GMT" } ]
1,389,830,400,000
[ [ "Jonsson", "Anders", "" ] ]
1401.3489
Robert Mateescu
Robert Mateescu, Kalev Kask, Vibhav Gogate, Rina Dechter
Join-Graph Propagation Algorithms
null
Journal Of Artificial Intelligence Research, Volume 37, pages 279-328, 2010
10.1613/jair.2842
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The paper investigates parameterized approximate message-passing schemes that are based on bounded inference and are inspired by Pearl's belief propagation algorithm (BP). We start with the bounded inference mini-clustering algorithm and then move to the iterative scheme called Iterative Join-Graph Propagation (IJGP), that combines both iteration and bounded inference. Algorithm IJGP belongs to the class of Generalized Belief Propagation algorithms, a framework that allowed connections with approximate algorithms from statistical physics and is shown empirically to surpass the performance of mini-clustering and belief propagation, as well as a number of other state-of-the-art algorithms on several classes of networks. We also provide insight into the accuracy of iterative BP and IJGP by relating these algorithms to well known classes of constraint propagation schemes.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:38:39 GMT" } ]
1,389,830,400,000
[ [ "Mateescu", "Robert", "" ], [ "Kask", "Kalev", "" ], [ "Gogate", "Vibhav", "" ], [ "Dechter", "Rina", "" ] ]
1401.3490
William Yeoh
William Yeoh, Ariel Felner, Sven Koenig
BnB-ADOPT: An Asynchronous Branch-and-Bound DCOP Algorithm
null
Journal Of Artificial Intelligence Research, Volume 38, pages 85-133, 2010
10.1613/jair.2849
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Distributed constraint optimization (DCOP) problems are a popular way of formulating and solving agent-coordination problems. A DCOP problem is a problem where several agents coordinate their values such that the sum of the resulting constraint costs is minimal. It is often desirable to solve DCOP problems with memory-bounded and asynchronous algorithms. We introduce Branch-and-Bound ADOPT (BnB-ADOPT), a memory-bounded asynchronous DCOP search algorithm that uses the message-passing and communication framework of ADOPT (Modi, Shen, Tambe, and Yokoo, 2005), a well known memory-bounded asynchronous DCOP search algorithm, but changes the search strategy of ADOPT from best-first search to depth-first branch-and-bound search. Our experimental results show that BnB-ADOPT finds cost-minimal solutions up to one order of magnitude faster than ADOPT for a variety of large DCOP problems and is as fast as NCBB, a memory-bounded synchronous DCOP search algorithm, for most of these DCOP problems. Additionally, it is often desirable to find bounded-error solutions for DCOP problems within a reasonable amount of time since finding cost-minimal solutions is NP-hard. The existing bounded-error approximation mechanism allows users only to specify an absolute error bound on the solution cost but a relative error bound is often more intuitive. Thus, we present two new bounded-error approximation mechanisms that allow for relative error bounds and implement them on top of BnB-ADOPT.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:39:26 GMT" } ]
1,389,830,400,000
[ [ "Yeoh", "William", "" ], [ "Felner", "Ariel", "" ], [ "Koenig", "Sven", "" ] ]
1401.3491
Emil Keyder
Emil Keyder, Hector Geffner
Soft Goals Can Be Compiled Away
null
Journal Of Artificial Intelligence Research, Volume 36, pages 547-556, 2009
10.1613/jair.2857
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Soft goals extend the classical model of planning with a simple model of preferences. The best plans are then not the ones with least cost but the ones with maximum utility, where the utility of a plan is the sum of the utilities of the soft goals achieved minus the plan cost. Finding plans with high utility appears to involve two linked problems: choosing a subset of soft goals to achieve and finding a low-cost plan to achieve them. New search algorithms and heuristics have been developed for planning with soft goals, and a new track has been introduced in the International Planning Competition (IPC) to test their performance. In this note, we show however that these extensions are not needed: soft goals do not increase the expressive power of the basic model of planning with action costs, as they can easily be compiled away. We apply this compilation to the problems of the net-benefit track of the most recent IPC, and show that optimal and satisficing cost-based planners do better on the compiled problems than optimal and satisficing net-benefit planners on the original problems with explicit soft goals. Furthermore, we show that penalties, or negative preferences expressing conditions to avoid, can also be compiled away using a similar idea.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:39:49 GMT" } ]
1,389,830,400,000
[ [ "Keyder", "Emil", "" ], [ "Geffner", "Hector", "" ] ]
1401.3492
Frank Hutter
Frank Hutter, Thomas Stuetzle, Kevin Leyton-Brown, Holger H. Hoos
ParamILS: An Automatic Algorithm Configuration Framework
null
Journal Of Artificial Intelligence Research, Volume 36, pages 267-306, 2009
10.1613/jair.2861
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The identification of performance-optimizing parameter settings is an important part of the development and application of algorithms. We describe an automatic framework for this algorithm configuration problem. More formally, we provide methods for optimizing a target algorithm's performance on a given class of problem instances by varying a set of ordinal and/or categorical parameters. We review a family of local-search-based algorithm configuration procedures and present novel techniques for accelerating them by adaptively limiting the time spent for evaluating individual configurations. We describe the results of a comprehensive experimental evaluation of our methods, based on the configuration of prominent complete and incomplete algorithms for SAT. We also present what is, to our knowledge, the first published work on automatically configuring the CPLEX mixed integer programming solver. All the algorithms we considered had default parameter settings that were manually identified with considerable effort. Nevertheless, using our automated algorithm configuration procedures, we achieved substantial and consistent performance improvements.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:40:11 GMT" } ]
1,389,830,400,000
[ [ "Hutter", "Frank", "" ], [ "Stuetzle", "Thomas", "" ], [ "Leyton-Brown", "Kevin", "" ], [ "Hoos", "Holger H.", "" ] ]
1401.3493
Uzi Zahavi
Uzi Zahavi, Ariel Felner, Neil Burch, Robert C. Holte
Predicting the Performance of IDA* using Conditional Distributions
null
Journal Of Artificial Intelligence Research, Volume 37, pages 41-83, 2010
10.1613/jair.2890
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Korf, Reid, and Edelkamp introduced a formula to predict the number of nodes IDA* will expand on a single iteration for a given consistent heuristic, and experimentally demonstrated that it could make very accurate predictions. In this paper we show that, in addition to requiring the heuristic to be consistent, their formulas predictions are accurate only at levels of the brute-force search tree where the heuristic values obey the unconditional distribution that they defined and then used in their formula. We then propose a new formula that works well without these requirements, i.e., it can make accurate predictions of IDA*s performance for inconsistent heuristics and if the heuristic values in any level do not obey the unconditional distribution. In order to achieve this we introduce the conditional distribution of heuristic values which is a generalization of their unconditional heuristic distribution. We also provide extensions of our formula that handle individual start states and the augmentation of IDA* with bidirectional pathmax (BPMX), a technique for propagating heuristic values when inconsistent heuristics are used. Experimental results demonstrate the accuracy of our new method and all its variations.
[ { "version": "v1", "created": "Wed, 15 Jan 2014 05:41:44 GMT" } ]
1,389,830,400,000
[ [ "Zahavi", "Uzi", "" ], [ "Felner", "Ariel", "" ], [ "Burch", "Neil", "" ], [ "Holte", "Robert C.", "" ] ]
1401.3827
Ruijie He
Ruijie He, Emma Brunskill, Nicholas Roy
Efficient Planning under Uncertainty with Macro-actions
null
Journal Of Artificial Intelligence Research, Volume 40, pages 523-570, 2011
10.1613/jair.3171
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Deciding how to act in partially observable environments remains an active area of research. Identifying good sequences of decisions is particularly challenging when good control performance requires planning multiple steps into the future in domains with many states. Towards addressing this challenge, we present an online, forward-search algorithm called the Posterior Belief Distribution (PBD). PBD leverages a novel method for calculating the posterior distribution over beliefs that result after a sequence of actions is taken, given the set of observation sequences that could be received during this process. This method allows us to efficiently evaluate the expected reward of a sequence of primitive actions, which we refer to as macro-actions. We present a formal analysis of our approach, and examine its performance on two very large simulation experiments: scientific exploration and a target monitoring domain. We also demonstrate our algorithm being used to control a real robotic helicopter in a target monitoring experiment, which suggests that our approach has practical potential for planning in real-world, large partially observable domains where a multi-step lookahead is required to achieve good performance.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:36:09 GMT" } ]
1,389,916,800,000
[ [ "He", "Ruijie", "" ], [ "Brunskill", "Emma", "" ], [ "Roy", "Nicholas", "" ] ]
1401.3830
Henrik Reif Andersen
Henrik Reif Andersen, Tarik Hadzic, David Pisinger
Interactive Cost Configuration Over Decision Diagrams
null
Journal Of Artificial Intelligence Research, Volume 37, pages 99-139, 2010
10.1613/jair.2905
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In many AI domains such as product configuration, a user should interactively specify a solution that must satisfy a set of constraints. In such scenarios, offline compilation of feasible solutions into a tractable representation is an important approach to delivering efficient backtrack-free user interaction online. In particular,binary decision diagrams (BDDs) have been successfully used as a compilation target for product and service configuration. In this paper we discuss how to extend BDD-based configuration to scenarios involving cost functions which express user preferences. We first show that an efficient, robust and easy to implement extension is possible if the cost function is additive, and feasible solutions are represented using multi-valued decision diagrams (MDDs). We also discuss the effect on MDD size if the cost function is non-additive or if it is encoded explicitly into MDD. We then discuss interactive configuration in the presence of multiple cost functions. We prove that even in its simplest form, multiple-cost configuration is NP-hard in the input MDD. However, for solving two-cost configuration we develop a pseudo-polynomial scheme and a fully polynomial approximation scheme. The applicability of our approach is demonstrated through experiments over real-world configuration models and product-catalogue datasets. Response times are generally within a fraction of a second even for very large instances.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:48:15 GMT" } ]
1,389,916,800,000
[ [ "Andersen", "Henrik Reif", "" ], [ "Hadzic", "Tarik", "" ], [ "Pisinger", "David", "" ] ]
1401.3831
Raghav Aras
Raghav Aras, Alain Dutech
An Investigation into Mathematical Programming for Finite Horizon Decentralized POMDPs
null
Journal Of Artificial Intelligence Research, Volume 37, pages 329-396, 2010
10.1613/jair.2915
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Decentralized planning in uncertain environments is a complex task generally dealt with by using a decision-theoretic approach, mainly through the framework of Decentralized Partially Observable Markov Decision Processes (DEC-POMDPs). Although DEC-POMDPS are a general and powerful modeling tool, solving them is a task with an overwhelming complexity that can be doubly exponential. In this paper, we study an alternate formulation of DEC-POMDPs relying on a sequence-form representation of policies. From this formulation, we show how to derive Mixed Integer Linear Programming (MILP) problems that, once solved, give exact optimal solutions to the DEC-POMDPs. We show that these MILPs can be derived either by using some combinatorial characteristics of the optimal solutions of the DEC-POMDPs or by using concepts borrowed from game theory. Through an experimental validation on classical test problems from the DEC-POMDP literature, we compare our approach to existing algorithms. Results show that mathematical programming outperforms dynamic programming but is less efficient than forward search, except for some particular problems. The main contributions of this work are the use of mathematical programming for DEC-POMDPs and a better understanding of DEC-POMDPs and of their solutions. Besides, we argue that our alternate representation of DEC-POMDPs could be helpful for designing novel algorithms looking for approximate solutions to DEC-POMDPs.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:49:14 GMT" } ]
1,389,916,800,000
[ [ "Aras", "Raghav", "" ], [ "Dutech", "Alain", "" ] ]
1401.3833
Bozhena Bidyuk
Bozhena Bidyuk, Rina Dechter, Emma Rollon
Active Tuples-based Scheme for Bounding Posterior Beliefs
null
Journal Of Artificial Intelligence Research, Volume 39, pages 335-371, 2010
10.1613/jair.2945
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The paper presents a scheme for computing lower and upper bounds on the posterior marginals in Bayesian networks with discrete variables. Its power lies in its ability to use any available scheme that bounds the probability of evidence or posterior marginals and enhance its performance in an anytime manner. The scheme uses the cutset conditioning principle to tighten existing bounding schemes and to facilitate anytime behavior, utilizing a fixed number of cutset tuples. The accuracy of the bounds improves as the number of used cutset tuples increases and so does the computation time. We demonstrate empirically the value of our scheme for bounding posterior marginals and probability of evidence using a variant of the bound propagation algorithm as a plug-in scheme.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:50:19 GMT" } ]
1,389,916,800,000
[ [ "Bidyuk", "Bozhena", "" ], [ "Dechter", "Rina", "" ], [ "Rollon", "Emma", "" ] ]
1401.3835
Ivan Jos\'e Varzinczak
Ivan Jos\'e Varzinczak
On Action Theory Change
null
Journal Of Artificial Intelligence Research, Volume 37, pages 189-246, 2010
10.1613/jair.2959
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
As historically acknowledged in the Reasoning about Actions and Change community, intuitiveness of a logical domain description cannot be fully automated. Moreover, like any other logical theory, action theories may also evolve, and thus knowledge engineers need revision methods to help in accommodating new incoming information about the behavior of actions in an adequate manner. The present work is about changing action domain descriptions in multimodal logic. Its contribution is threefold: first we revisit the semantics of action theory contraction proposed in previous work, giving more robust operators that express minimal change based on a notion of distance between Kripke-models. Second we give algorithms for syntactical action theory contraction and establish their correctness with respect to our semantics for those action theories that satisfy a principle of modularity investigated in previous work. Since modularity can be ensured for every action theory and, as we show here, needs to be computed at most once during the evolution of a domain description, it does not represent a limitation at all to the method here studied. Finally we state AGM-like postulates for action theory contraction and assess the behavior of our operators with respect to them. Moreover, we also address the revision counterpart of action theory change, showing that it benefits from our semantics for contraction.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:51:08 GMT" } ]
1,389,916,800,000
[ [ "Varzinczak", "Ivan José", "" ] ]
1401.3838
Claudette Cayrol
Claudette Cayrol, Florence Dupin de Saint-Cyr, Marie-Christine Lagasquie-Schiex
Change in Abstract Argumentation Frameworks: Adding an Argument
null
Journal Of Artificial Intelligence Research, Volume 38, pages 49-84, 2010
10.1613/jair.2965
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we address the problem of change in an abstract argumentation system. We focus on a particular change: the addition of a new argument which interacts with previous arguments. We study the impact of such an addition on the outcome of the argumentation system, more particularly on the set of its extensions. Several properties for this change operation are defined by comparing the new set of extensions to the initial one, these properties are called structural when the comparisons are based on set-cardinality or set-inclusion relations. Several other properties are proposed where comparisons are based on the status of some particular arguments: the accepted arguments; these properties refer to the evolution of this status during the change, e.g., Monotony and Priority to Recency. All these properties may be more or less desirable according to specific applications. They are studied under two particular semantics: the grounded and preferred semantics.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:52:08 GMT" } ]
1,389,916,800,000
[ [ "Cayrol", "Claudette", "" ], [ "de Saint-Cyr", "Florence Dupin", "" ], [ "Lagasquie-Schiex", "Marie-Christine", "" ] ]
1401.3839
Silvia Richter
Silvia Richter, Matthias Westphal
The LAMA Planner: Guiding Cost-Based Anytime Planning with Landmarks
null
Journal Of Artificial Intelligence Research, Volume 39, pages 127-177, 2010
10.1613/jair.2972
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
LAMA is a classical planning system based on heuristic forward search. Its core feature is the use of a pseudo-heuristic derived from landmarks, propositional formulas that must be true in every solution of a planning task. LAMA builds on the Fast Downward planning system, using finite-domain rather than binary state variables and multi-heuristic search. The latter is employed to combine the landmark heuristic with a variant of the well-known FF heuristic. Both heuristics are cost-sensitive, focusing on high-quality solutions in the case where actions have non-uniform cost. A weighted A* search is used with iteratively decreasing weights, so that the planner continues to search for plans of better quality until the search is terminated. LAMA showed best performance among all planners in the sequential satisficing track of the International Planning Competition 2008. In this paper we present the system in detail and investigate which features of LAMA are crucial for its performance. We present individual results for some of the domains used at the competition, demonstrating good and bad cases for the techniques implemented in LAMA. Overall, we find that using landmarks improves performance, whereas the incorporation of action costs into the heuristic estimators proves not to be beneficial. We show that in some domains a search that ignores cost solves far more problems, raising the question of how to deal with action costs more effectively in the future. The iterated weighted A* search greatly improves results, and shows synergy effects with the use of landmarks.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:52:55 GMT" } ]
1,389,916,800,000
[ [ "Richter", "Silvia", "" ], [ "Westphal", "Matthias", "" ] ]
1401.3841
Mark Owen Riedl
Mark Owen Riedl, Robert Michael Young
Narrative Planning: Balancing Plot and Character
null
Journal Of Artificial Intelligence Research, Volume 39, pages 217-268, 2010
10.1613/jair.2989
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Narrative, and in particular storytelling, is an important part of the human experience. Consequently, computational systems that can reason about narrative can be more effective communicators, entertainers, educators, and trainers. One of the central challenges in computational narrative reasoning is narrative generation, the automated creation of meaningful event sequences. There are many factors -- logical and aesthetic -- that contribute to the success of a narrative artifact. Central to this success is its understandability. We argue that the following two attributes of narratives are universal: (a) the logical causal progression of plot, and (b) character believability. Character believability is the perception by the audience that the actions performed by characters do not negatively impact the audiences suspension of disbelief. Specifically, characters must be perceived by the audience to be intentional agents. In this article, we explore the use of refinement search as a technique for solving the narrative generation problem -- to find a sound and believable sequence of character actions that transforms an initial world state into a world state in which goal propositions hold. We describe a novel refinement search planning algorithm -- the Intent-based Partial Order Causal Link (IPOCL) planner -- that, in addition to creating causally sound plot progression, reasons about character intentionality by identifying possible character goals that explain their actions and creating plan structures that explain why those characters commit to their goals. We present the results of an empirical evaluation that demonstrates that narrative plans generated by the IPOCL algorithm support audience comprehension of character intentions better than plans generated by conventional partial-order planners.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:54:07 GMT" } ]
1,389,916,800,000
[ [ "Riedl", "Mark Owen", "" ], [ "Young", "Robert Michael", "" ] ]
1401.3842
David Lesaint
David Lesaint, Deepak Mehta, Barry O'Sullivan, Luis Quesada, Nic Wilson
Developing Approaches for Solving a Telecommunications Feature Subscription Problem
null
Journal Of Artificial Intelligence Research, Volume 38, pages 271-305, 2010
10.1613/jair.2992
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Call control features (e.g., call-divert, voice-mail) are primitive options to which users can subscribe off-line to personalise their service. The configuration of a feature subscription involves choosing and sequencing features from a catalogue and is subject to constraints that prevent undesirable feature interactions at run-time. When the subscription requested by a user is inconsistent, one problem is to find an optimal relaxation, which is a generalisation of the feedback vertex set problem on directed graphs, and thus it is an NP-hard task. We present several constraint programming formulations of the problem. We also present formulations using partial weighted maximum Boolean satisfiability and mixed integer linear programming. We study all these formulations by experimentally comparing them on a variety of randomly generated instances of the feature subscription problem.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:54:27 GMT" } ]
1,389,916,800,000
[ [ "Lesaint", "David", "" ], [ "Mehta", "Deepak", "" ], [ "O'Sullivan", "Barry", "" ], [ "Quesada", "Luis", "" ], [ "Wilson", "Nic", "" ] ]
1401.3846
Graeme Gange
Graeme Gange, Peter James Stuckey, Vitaly Lagoon
Fast Set Bounds Propagation Using a BDD-SAT Hybrid
null
Journal Of Artificial Intelligence Research, Volume 38, pages 307-338, 2010
10.1613/jair.3014
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Binary Decision Diagram (BDD) based set bounds propagation is a powerful approach to solving set-constraint satisfaction problems. However, prior BDD based techniques in- cur the significant overhead of constructing and manipulating graphs during search. We present a set-constraint solver which combines BDD-based set-bounds propagators with the learning abilities of a modern SAT solver. Together with a number of improvements beyond the basic algorithm, this solver is highly competitive with existing propagation based set constraint solvers.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:56:56 GMT" } ]
1,389,916,800,000
[ [ "Gange", "Graeme", "" ], [ "Stuckey", "Peter James", "" ], [ "Lagoon", "Vitaly", "" ] ]
1401.3847
Jia-Hong Wu
Jia-Hong Wu, Robert Givan
Automatic Induction of Bellman-Error Features for Probabilistic Planning
null
Journal Of Artificial Intelligence Research, Volume 38, pages 687-755, 2010
10.1613/jair.3021
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Domain-specific features are important in representing problem structure throughout machine learning and decision-theoretic planning. In planning, once state features are provided, domain-independent algorithms such as approximate value iteration can learn weighted combinations of those features that often perform well as heuristic estimates of state value (e.g., distance to the goal). Successful applications in real-world domains often require features crafted by human experts. Here, we propose automatic processes for learning useful domain-specific feature sets with little or no human intervention. Our methods select and add features that describe state-space regions of high inconsistency in the Bellman equation (statewise Bellman error) during approximate value iteration. Our method can be applied using any real-valued-feature hypothesis space and corresponding learning method for selecting features from training sets of state-value pairs. We evaluate the method with hypothesis spaces defined by both relational and propositional feature languages, using nine probabilistic planning domains. We show that approximate value iteration using a relational feature space performs at the state-of-the-art in domain-independent stochastic relational planning. Our method provides the first domain-independent approach that plays Tetris successfully (without human-engineered features).
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:57:22 GMT" } ]
1,389,916,800,000
[ [ "Wu", "Jia-Hong", "" ], [ "Givan", "Robert", "" ] ]
1401.3848
Alexander Feldman
Alexander Feldman, Gregory Provan, Arjan van Gemund
Approximate Model-Based Diagnosis Using Greedy Stochastic Search
null
Journal Of Artificial Intelligence Research, Volume 38, pages 371-413, 2010
10.1613/jair.3025
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
We propose a StochAstic Fault diagnosis AlgoRIthm, called SAFARI, which trades off guarantees of computing minimal diagnoses for computational efficiency. We empirically demonstrate, using the 74XXX and ISCAS-85 suites of benchmark combinatorial circuits, that SAFARI achieves several orders-of-magnitude speedup over two well-known deterministic algorithms, CDA* and HA*, for multiple-fault diagnoses; further, SAFARI can compute a range of multiple-fault diagnoses that CDA* and HA* cannot. We also prove that SAFARI is optimal for a range of propositional fault models, such as the widely-used weak-fault models (models with ignorance of abnormal behavior). We discuss the optimality of SAFARI in a class of strong-fault circuit models with stuck-at failure modes. By modeling the algorithm itself as a Markov chain, we provide exact bounds on the minimality of the diagnosis computed. SAFARI also displays strong anytime behavior, and will return a diagnosis after any non-trivial inference time.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:57:50 GMT" } ]
1,389,916,800,000
[ [ "Feldman", "Alexander", "" ], [ "Provan", "Gregory", "" ], [ "van Gemund", "Arjan", "" ] ]
1401.3850
Alexander Feldman
Alexander Feldman, Gregory Provan, Arjan van Gemund
A Model-Based Active Testing Approach to Sequential Diagnosis
null
Journal Of Artificial Intelligence Research, Volume 39, pages 301-334, 2010
10.1613/jair.3031
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Model-based diagnostic reasoning often leads to a large number of diagnostic hypotheses. The set of diagnoses can be reduced by taking into account extra observations (passive monitoring), measuring additional variables (probing) or executing additional tests (sequential diagnosis/test sequencing). In this paper we combine the above approaches with techniques from Automated Test Pattern Generation (ATPG) and Model-Based Diagnosis (MBD) into a framework called FRACTAL (FRamework for ACtive Testing ALgorithms). Apart from the inputs and outputs that connect a system to its environment, in active testing we consider additional input variables to which a sequence of test vectors can be supplied. We address the computationally hard problem of computing optimal control assignments (as defined in FRACTAL) in terms of a greedy approximation algorithm called FRACTAL-G. We compare the decrease in the number of remaining minimal cardinality diagnoses of FRACTAL-G to that of two more FRACTAL algorithms: FRACTAL-ATPG and FRACTAL-P. FRACTAL-ATPG is based on ATPG and sequential diagnosis while FRACTAL-P is based on probing and, although not an active testing algorithm, provides a baseline for comparing the lower bound on the number of reachable diagnoses for the FRACTAL algorithms. We empirically evaluate the trade-offs of the three FRACTAL algorithms by performing extensive experimentation on the ISCAS85/74XXX benchmark of combinational circuits.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:58:46 GMT" } ]
1,389,916,800,000
[ [ "Feldman", "Alexander", "" ], [ "Provan", "Gregory", "" ], [ "van Gemund", "Arjan", "" ] ]
1401.3853
Michael Katz
Michael Katz, Carmel Domshlak
Implicit Abstraction Heuristics
null
Journal Of Artificial Intelligence Research, Volume 39, pages 51-126, 2010
10.1613/jair.3063
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
State-space search with explicit abstraction heuristics is at the state of the art of cost-optimal planning. These heuristics are inherently limited, nonetheless, because the size of the abstract space must be bounded by some, even if a very large, constant. Targeting this shortcoming, we introduce the notion of (additive) implicit abstractions, in which the planning task is abstracted by instances of tractable fragments of optimal planning. We then introduce a concrete setting of this framework, called fork-decomposition, that is based on two novel fragments of tractable cost-optimal planning. The induced admissible heuristics are then studied formally and empirically. This study testifies for the accuracy of the fork decomposition heuristics, yet our empirical evaluation also stresses the tradeoff between their accuracy and the runtime complexity of computing them. Indeed, some of the power of the explicit abstraction heuristics comes from precomputing the heuristic function offline and then determining h(s) for each evaluated state s by a very fast lookup in a database. By contrast, while fork-decomposition heuristics can be calculated in polynomial time, computing them is far from being fast. To address this problem, we show that the time-per-node complexity bottleneck of the fork-decomposition heuristics can be successfully overcome. We demonstrate that an equivalent of the explicit abstraction notion of a database exists for the fork-decomposition abstractions as well, despite their exponential-size abstract spaces. We then verify empirically that heuristic search with the databased" fork-decomposition heuristics favorably competes with the state of the art of cost-optimal planning.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 04:59:55 GMT" } ]
1,389,916,800,000
[ [ "Katz", "Michael", "" ], [ "Domshlak", "Carmel", "" ] ]
1401.3854
Bonny Banerjee
Bonny Banerjee, B. Chandrasekaran
A Constraint Satisfaction Framework for Executing Perceptions and Actions in Diagrammatic Reasoning
null
Journal Of Artificial Intelligence Research, Volume 39, pages 373-427, 2010
10.1613/jair.3069
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Diagrammatic reasoning (DR) is pervasive in human problem solving as a powerful adjunct to symbolic reasoning based on language-like representations. The research reported in this paper is a contribution to building a general purpose DR system as an extension to a SOAR-like problem solving architecture. The work is in a framework in which DR is modeled as a process where subtasks are solved, as appropriate, either by inference from symbolic representations or by interaction with a diagram, i.e., perceiving specified information from a diagram or modifying/creating objects in a diagram in specified ways according to problem solving needs. The perceptions and actions in most DR systems built so far are hand-coded for the specific application, even when the rest of the system is built using the general architecture. The absence of a general framework for executing perceptions/actions poses as a major hindrance to using them opportunistically -- the essence of open-ended search in problem solving. Our goal is to develop a framework for executing a wide variety of specified perceptions and actions across tasks/domains without human intervention. We observe that the domain/task-specific visual perceptions/actions can be transformed into domain/task-independent spatial problems. We specify a spatial problem as a quantified constraint satisfaction problem in the real domain using an open-ended vocabulary of properties, relations and actions involving three kinds of diagrammatic objects -- points, curves, regions. Solving a spatial problem from this specification requires computing the equivalent simplified quantifier-free expression, the complexity of which is inherently doubly exponential. We represent objects as configuration of simple elements to facilitate decomposition of complex problems into simpler and similar subproblems. We show that, if the symbolic solution to a subproblem can be expressed concisely, quantifiers can be eliminated from spatial problems in low-order polynomial time using similar previously solved subproblems. This requires determining the similarity of two problems, the existence of a mapping between them computable in polynomial time, and designing a memory for storing previously solved problems so as to facilitate search. The efficacy of the idea is shown by time complexity analysis. We demonstrate the proposed approach by executing perceptions and actions involved in DR tasks in two army applications.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 05:00:46 GMT" } ]
1,389,916,800,000
[ [ "Banerjee", "Bonny", "" ], [ "Chandrasekaran", "B.", "" ] ]
1401.3857
Vadim Bulitko
Vadim Bulitko, Yngvi Bj\"ornsson, Ramon Lawrence
Case-Based Subgoaling in Real-Time Heuristic Search for Video Game Pathfinding
null
Journal Of Artificial Intelligence Research, Volume 39, pages 269-300, 2010
10.1613/jair.3076
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Real-time heuristic search algorithms satisfy a constant bound on the amount of planning per action, independent of problem size. As a result, they scale up well as problems become larger. This property would make them well suited for video games where Artificial Intelligence controlled agents must react quickly to user commands and to other agents actions. On the downside, real-time search algorithms employ learning methods that frequently lead to poor solution quality and cause the agent to appear irrational by re-visiting the same problem states repeatedly. The situation changed recently with a new algorithm, D LRTA*, which attempted to eliminate learning by automatically selecting subgoals. D LRTA* is well poised for video games, except it has a complex and memory-demanding pre-computation phase during which it builds a database of subgoals. In this paper, we propose a simpler and more memory-efficient way of pre-computing subgoals thereby eliminating the main obstacle to applying state-of-the-art real-time search methods in video games. The new algorithm solves a number of randomly chosen problems off-line, compresses the solutions into a series of subgoals and stores them in a database. When presented with a novel problem on-line, it queries the database for the most similar previously solved case and uses its subgoals to solve the problem. In the domain of pathfinding on four large video game maps, the new algorithm delivers solutions eight times better while using 57 times less memory and requiring 14% less pre-computation time.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 05:02:02 GMT" } ]
1,389,916,800,000
[ [ "Bulitko", "Vadim", "" ], [ "Björnsson", "Yngvi", "" ], [ "Lawrence", "Ramon", "" ] ]
1401.3860
Tobias Lang
Tobias Lang, Marc Toussaint
Planning with Noisy Probabilistic Relational Rules
null
Journal Of Artificial Intelligence Research, Volume 39, pages 1-49, 2010
10.1613/jair.3093
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
Noisy probabilistic relational rules are a promising world model representation for several reasons. They are compact and generalize over world instantiations. They are usually interpretable and they can be learned effectively from the action experiences in complex worlds. We investigate reasoning with such rules in grounded relational domains. Our algorithms exploit the compactness of rules for efficient and flexible decision-theoretic planning. As a first approach, we combine these rules with the Upper Confidence Bounds applied to Trees (UCT) algorithm based on look-ahead trees. Our second approach converts these rules into a structured dynamic Bayesian network representation and predicts the effects of action sequences using approximate inference and beliefs over world states. We evaluate the effectiveness of our approaches for planning in a simulated complex 3D robot manipulation scenario with an articulated manipulator and realistic physics and in domains of the probabilistic planning competition. Empirical results show that our methods can solve problems where existing methods fail.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 05:03:40 GMT" } ]
1,389,916,800,000
[ [ "Lang", "Tobias", "" ], [ "Toussaint", "Marc", "" ] ]
1401.3863
Gerold J\"ager
Gerold J\"ager, Weixiong Zhang
An Effective Algorithm for and Phase Transitions of the Directed Hamiltonian Cycle Problem
null
Journal Of Artificial Intelligence Research, Volume 39, pages 663-687, 2010
10.1613/jair.3109
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
The Hamiltonian cycle problem (HCP) is an important combinatorial problem with applications in many areas. It is among the first problems used for studying intrinsic properties, including phase transitions, of combinatorial problems. While thorough theoretical and experimental analyses have been made on the HCP in undirected graphs, a limited amount of work has been done for the HCP in directed graphs (DHCP). The main contribution of this work is an effective algorithm for the DHCP. Our algorithm explores and exploits the close relationship between the DHCP and the Assignment Problem (AP) and utilizes a technique based on Boolean satisfiability (SAT). By combining effective algorithms for the AP and SAT, our algorithm significantly outperforms previous exact DHCP algorithms, including an algorithm based on the award-winning Concorde TSP algorithm. The second result of the current study is an experimental analysis of phase transitions of the DHCP, verifying and refining a known phase transition of the DHCP.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 05:04:57 GMT" } ]
1,389,916,800,000
[ [ "Jäger", "Gerold", "" ], [ "Zhang", "Weixiong", "" ] ]
1401.3867
Aaron Hunter
Aaron Hunter, James P. Delgrande
Iterated Belief Change Due to Actions and Observations
null
Journal Of Artificial Intelligence Research, Volume 40, pages 269-304, 2011
10.1613/jair.3132
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In action domains where agents may have erroneous beliefs, reasoning about the effects of actions involves reasoning about belief change. In this paper, we use a transition system approach to reason about the evolution of an agents beliefs as actions are executed. Some actions cause an agent to perform belief revision while others cause an agent to perform belief update, but the interaction between revision and update can be non-elementary. We present a set of rationality properties describing the interaction between revision and update, and we introduce a new class of belief change operators for reasoning about alternating sequences of revisions and updates. Our belief change operators can be characterized in terms of a natural shifting operation on total pre-orderings over interpretations. We compare our approach with related work on iterated belief change due to action, and we conclude with some directions for future research.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 05:06:49 GMT" } ]
1,389,916,800,000
[ [ "Hunter", "Aaron", "" ], [ "Delgrande", "James P.", "" ] ]
1401.3872
Christophe Lecoutre
Christophe Lecoutre, Stephane Cardon, Julien Vion
Second-Order Consistencies
null
Journal Of Artificial Intelligence Research, Volume 40, pages 175-219, 2011
10.1613/jair.3180
null
cs.AI
http://arxiv.org/licenses/nonexclusive-distrib/1.0/
In this paper, we propose a comprehensive study of second-order consistencies (i.e., consistencies identifying inconsistent pairs of values) for constraint satisfaction. We build a full picture of the relationships existing between four basic second-order consistencies, namely path consistency (PC), 3-consistency (3C), dual consistency (DC) and 2-singleton arc consistency (2SAC), as well as their conservative and strong variants. Interestingly, dual consistency is an original property that can be established by using the outcome of the enforcement of generalized arc consistency (GAC), which makes it rather easy to obtain since constraint solvers typically maintain GAC during search. On binary constraint networks, DC is equivalent to PC, but its restriction to existing constraints, called conservative dual consistency (CDC), is strictly stronger than traditional conservative consistencies derived from path consistency, namely partial path consistency (PPC) and conservative path consistency (CPC). After introducing a general algorithm to enforce strong (C)DC, we present the results of an experimentation over a wide range of benchmarks that demonstrate the interest of (conservative) dual consistency. In particular, we show that enforcing (C)DC before search clearly improves the performance of MAC (the algorithm that maintains GAC during search) on several binary and non-binary structured problems.
[ { "version": "v1", "created": "Thu, 16 Jan 2014 05:09:30 GMT" } ]
1,389,916,800,000
[ [ "Lecoutre", "Christophe", "" ], [ "Cardon", "Stephane", "" ], [ "Vion", "Julien", "" ] ]