Goto

Collaborating Authors

 Europe


Adding Diversity to Classical Heuristic Planning

AAAI Conferences

In this paper we propose a new algorithm for solving general two-player turn-taking games that performs symbolic search utilizing binary decision diagrams (BDDs). It consists of two stages: First, it determines all breadth-first search (BFS) layers using forward search and omitting duplicate detection, next, the solving process operates in backward direction only within these BFS layers thereby partitioning all BDDs according to the layers the states reside in. We provide experimental results for selected games and compare to a previous approach. This comparison shows that in most cases the new algorithm outperforms the existing one in terms of runtime and used memory so that it can solve games that could not be solved before with a general approach.


Layer-Abstraction for Symbolically Solving General Two-Player Games

AAAI Conferences

One of the latest prominent results was by Schaeffer In recent years general game playing has received an increasing et al. (2007), who were able to solve American Checkers after amount of attention, especially due to the annual more than ten years of computation and proved that the general game playing competition (Genesereth, Love, and optimal outcome is a draw. Of course, due to the domain Pell 2005) that is held at AAAI or IJCAI since 2005. In independent scenario, we cannot expect to come up with solutions general game playing the agents are provided a description for such complex games in general game playing. of a game according to certain rules and need to play it. In explicit representation, many general games are too In case of multi-player games the agents often play against complex to fit into RAM or even on a hard disk. So, to solve each other, while in case of single-player games the agent them we perform symbolic search, which utilizes binary decision tries to find a sequence of moves to reach a terminal state diagrams (BDDs) (Bryant 1986) as they decrease the where it can achieve the best reward possible. The authors memory consumption, if a good variable ordering is found. of the agents do not know which games will be played, so In this paper we will present a new approach to solve general no domain specific knowledge can be inserted.


Heuristic Contraction Hierarchies with Approximation Guarantee

AAAI Conferences

We present a new heuristic point-to-point shortest path algorithm based on contraction hierarchies (CH). Given an epsilon >= 0, we can prove that the length of the path computed by our algorithm is at most (1 + ε) times the length of the optimal (shortest) path. Exact CH is based on node contraction: removing nodes from a network and adding shortcuts to preserve shortest path distances. Our heuristic CH tries to avoid adding shortcuts even when a replacement path is (1+epsilon) times longer. However, we cannot avoid all such shortcuts, as we need to ensure that errors do not stack. Combinations with goal-directed techniques bring further speed-ups.


GPU Exploration of Two-Player Games with Perfect Hash Functions

AAAI Conferences

In this paper we improve solving two-player games by computing the game-theoretical value of every reachable state. A graphics processing unit located on the graphics card is used as a co-processor to accelerate the solution process. We exploit perfect hash functions to store the game states efficiently in memory and to transfer their ordinal representation between the host and the graphics card. As an application we validate Gasser's results that Nine-Men-Morris is a draw on a personal computer. Moreover, our solution is strong, while for the opening phase Gasser only provided a weak solution.


Preface

AAAI Conferences

Welcome to the Third International Symposium on a long line of research that was carried out in the Combinatorial Search (SoCS)! This is an important past decade by him and others about the important year for SoCS as we have established archival proceedings topic of search in nondeterministic environments. These proceedings are the Finally, we scheduled an important panel discussion result of hard work by many, from researchers to reviewers about the differences and mutual influence of domain and the publisher. Every submitted search for planning environments. Wheeler Ruml paper was assigned to three anonymous reviewers; moderates the panel, which includes three experts all experts in the topic of the paper.


An Influence Diagram-Based Approach for Estimating Staff Training in Software Industry

arXiv.org Artificial Intelligence

The successful completion of a software development process depends on the analytical capability and foresightedness of the project manager. For the project manager, the main intriguing task is to manage the risk factors as they adversely influence the completion deadline. One such key risk factor is staff training. The risk of this factor can be avoided by pre-judging the amount of training required by the staff. So, a procedure is required to help the project manager make this decision. This paper presents a system that uses influence diagrams to implement the risk model to aid decision making. The system also considers the cost of conducting the training, based on various risk factors such as, (i) Lack of experience with project software; (ii) Newly appointed staff; (iii) Staff not well versed with the required quality standards; and (iv) Lack of experience with project environment. The system provides estimated requirement details for staff training at the beginning of a software development project.


Learning from Profession Knowledge: Application on Knitting

arXiv.org Artificial Intelligence

Knowledge Management is a global process in companies. It includes all the processes that allow capitalization, sharing and evolution of the Knowledge Capital of the firm, generally recognized as a critical resource of the organization. Several approaches have been defined to capitalize knowledge but few of them study how to learn from this knowledge. We present in this paper an approach that helps to enhance learning from profession knowledge in an organisation. We apply our approach on knitting industry.


A formalism for causal explanations with an Answer Set Programming translation

arXiv.org Artificial Intelligence

We examine the practicality for a user of using Answer Set Programming (ASP) for representing logical formalisms. Our example is a formalism aiming at capturing causal explanations from causal information. We show the naturalness and relative efficiency of this translation job. We are interested in the ease for writing an ASP program. Limitations of the earlier systems made that in practice, the ``declarative aspect'' was more theoretical than practical. We show how recent improvements in working ASP systems facilitate the translation.


Logical Foundations of RDF(S) with Datatypes

Journal of Artificial Intelligence Research

The Resource Description Framework (RDF) is a Semantic Web standard that provides a data language, simply called RDF, as well as a lightweight ontology language, called RDF Schema. We investigate embeddings of RDF in logic and show how standard logic programming and description logic technology can be used for reasoning with RDF. We subsequently consider extensions of RDF with datatype support, considering D entailment, defined in the RDF semantics specification, and D* entailment, a semantic weakening of D entailment, introduced by ter Horst. We use the embeddings and properties of the logics to establish novel upper bounds for the complexity of deciding entailment. We subsequently establish two novel lower bounds, establishing that RDFS entailment is PTime-complete and that simple-D entailment is coNP-hard, when considering arbitrary datatypes, both in the size of the entailing graph. The results indicate that RDFS may not be as lightweight as one may expect.


Ultrametric and Generalized Ultrametric in Computational Logic and in Data Analysis

arXiv.org Machine Learning

Following a review of metric, ultrametric and generalized ultrametric, we review their application in data analysis. We show how they allow us to explore both geometry and topology of information, starting with measured data. Some themes are then developed based on the use of metric, ultrametric and generalized ultrametric in logic. In particular we study approximation chains in an ultrametric or generalized ultrametric context. Our aim in this work is to extend the scope of data analysis by facilitating reasoning based on the data analysis; and to show how quantitative and qualitative data analysis can be incorporated into logic programming.