Recently, strong equivalence for answer set programming has been studied intensively, and was shown to be beneficial for modular programming and automated optimization. In this paper we define the novel notion of stro...
详细信息
Recently, strong equivalence for answer set programming has been studied intensively, and was shown to be beneficial for modular programming and automated optimization. In this paper we define the novel notion of strong order equivalence for logic programs with preferences (ordered logic programs). Based on this definition we give, for several semantics for preference handling, necessary and sufficient conditions for programs to be strongly order equivalent. These results allow us also to associate a so-called SOE structure to each ordered logic program, such that two ordered logic programs are strongly order equivalent if and only if their SOE structures coincide. We also present the relationships among the studied semantics with respect to strong order equivalence, which differs considerably from their relationships with respect to preferred answersets. Furthermore, we study the computational complexity of several reasoning tasks associated to strong order equivalence. Finally, based on the obtained results, we present - for the first time - simplification methods for ordered logic programs.
Stream reasoning is an emerging research area focused on providing continuous reasoning solutions for data streams. The exponential growth in the availability of streaming data on the Web has seriously hindered the ap...
详细信息
Stream reasoning is an emerging research area focused on providing continuous reasoning solutions for data streams. The exponential growth in the availability of streaming data on the Web has seriously hindered the applicability of state-of-the-art expressive reasoners, limiting their applicability to process streaming information in a scalable way. In this scenario, in order to reduce the amount of data to reason upon at each iteration, we can leverage advances in continuous query processing over Semantic Web streams. Following this principle, in previous work we have combined semantic query processing and non-monotonic reasoning over data streams in the StreamRule system. In the approach, we specifically focused on the scalability of a rule layer based on a fragment of answer set programming (ASP). We recently expanded on this approach by designing an algorithm to analyze input dependency so as to enable parallel execution and combine the results. In this paper, we expand on this solution by providing i) a proof of correctness for the approach, ii) an extensive experimental evaluation for different levels of complexity of the input program, and iii) a clear characterization of all the algorithms involved in generating and splitting the graph and identifying heuristics for node duplication, as well as partitioning the reasoning process via input splitting and combining the results.
This paper presents the Argonauts multi-agent framework which was developed as part of a one year student project at Technische Universitat Dortmund. The Argonauts framework builds on a BDI approach to model rational ...
详细信息
This paper presents the Argonauts multi-agent framework which was developed as part of a one year student project at Technische Universitat Dortmund. The Argonauts framework builds on a BDI approach to model rational agents that act cooperatively in a dynamic and indeterministically changing environment. However, our agent model extends the traditional BDI approach in several aspects, most notably by incorporating motivation into the agent's goal selection mechanism. The framework has been applied by the Argonauts team in the 2010 version of the annual multi-agent programming contest organized by Technische Universitat Clausthal. In this paper, we present a high-level specification and analysis of the actual system used for solving the given scenario. We do this by applying the GAIA methodology, a high-level and iterative approach to model communication and roles in multi-agent scenarios. We further describe the technical details and insights gained during our participation in the multi-agent programming contest.
Equilibrium logic is a general purpose nonmonotonic reasoning formalism closely aligned with answer set programming (ASP). In particular it provides a logical foundation for ASP as well as an extension of the basic sy...
详细信息
Equilibrium logic is a general purpose nonmonotonic reasoning formalism closely aligned with answer set programming (ASP). In particular it provides a logical foundation for ASP as well as an extension of the basic syntax of answerset programs. We present an overview of equilibrium logic and its main properties and uses.
In this article, we describe the architecture, the language and the authoring tool of the PENG(ASP) system. This system supports the writing of non-monotonic specifications in controlled natural language with the help...
详细信息
In this article, we describe the architecture, the language and the authoring tool of the PENG(ASP) system. This system supports the writing of non-monotonic specifications in controlled natural language with the help of a web-based predictive text editor. This predictive editor communicates asynchronously with a controlled natural language processor that translates the specification text via discourse representation structures into executable answerset Programs (ASP). The controlled natural language processor additionally generates lookahead categories and anaphoric expressions for the author of a specification text, and it provides a paraphrase of the specification that clarifies the interpretation of the text by the machine. The predictive editor is a central component of the PENG(ASP) system;it guides the writing process and displays multiple sets of lookahead categories simultaneously for different possible sentence completions as well as anaphoric expressions, and supports the addition of new content words to the lexicon.
The recent application of Machine Learning techniques to the answer set programming (ASP) field proved to be effective. In particular, the multi-engine ASP solver ME-ASP is efficient: it is able to solve more instance...
详细信息
The recent application of Machine Learning techniques to the answer set programming (ASP) field proved to be effective. In particular, the multi-engine ASP solver ME-ASP is efficient: it is able to solve more instances than any other ASP system that participated to the 3rd ASP Competition on the 'System Track' benchmarks. In the ME-ASP approach, classification methods inductively learn offline algorithm selection policies starting from both a set of features of instances in a training set, and the solvers performance on such instances. In this article we present an improvement to the multi-engine framework of ME-ASP, in which we add the capability of updating the learned policies when the original approach fails to give good predictions. An experimental analysis, conducted on training and test sets of ground instances obtained from the ones submitted to the 'System Track' of the 3rd ASP Competition, shows that the policy adaptation improves the performance of ME-ASP when applied to test sets containing domains of instances that were not considered for training.
Nowadays, the popularity of online social networks (OSNs) has been increased tremendously. Meanwhile, a wide range of third-party applications (TPAs) facilitated by OSNs has made a significant contribution to their po...
详细信息
Nowadays, the popularity of online social networks (OSNs) has been increased tremendously. Meanwhile, a wide range of third-party applications (TPAs) facilitated by OSNs has made a significant contribution to their popularity. TPAs offer many attractive functionalities and services to the OSN users but pose serious privacy threats to the users. Therefore, it is essential to strictly regulate the divulgence of user data to TPAs. In this paper, we propose an access control framework calledAppMonitorto monitor and curb the user data to TPA. Further, we also introduce a relation-based access control policy model that uses predicate calculus to express data access policies. Analysis of the usability and correctness of the introduced policy model has been made, based on a logical model using answer set programming. A simplified prototype has been developed to show the feasibility of AppMonitor, and its effectiveness is shown through a user study.
The article introduces a logical framework for negotiation among dishonest agents. The framework relies on the use of abductive logic programming as a knowledge representation language for agents to deal with incomple...
详细信息
The article introduces a logical framework for negotiation among dishonest agents. The framework relies on the use of abductive logic programming as a knowledge representation language for agents to deal with incomplete information and preferences. The article shows how intentionally false or inaccurate information of agents can be encoded in the agents' knowledge bases. Such disinformation can be effectively used in the process of negotiation to have desired outcomes by agents. The negotiation processes are formulated under the answerset semantics of abductive logic programming, and they enable the exploration of various strategies that agents can employ in their negotiation. A preliminary implementation has been developed using the ASP-Prolog platform.
We discuss applications of ASP in robotic planning, considering (1) full observability and complete knowledge and (2) with incomplete knowledge and partial observability. We emphasize the strengths of ASP as a useful ...
详细信息
We discuss applications of ASP in robotic planning, considering (1) full observability and complete knowledge and (2) with incomplete knowledge and partial observability. We emphasize the strengths of ASP as a useful knowledge representation and reasoning paradigm to integrate AI and robotics, as well as its flexibility to provide different levels of integration of feasibility checks with planning.
We present a novel implementation of Defeasible Deontic Logic as an answer set programming meta-program, and we evaluate the performance of the implementation against a recent set of benchmarks.
We present a novel implementation of Defeasible Deontic Logic as an answer set programming meta-program, and we evaluate the performance of the implementation against a recent set of benchmarks.
暂无评论