We first embed Pearce's equilibrium logic and Ferraris's propositional general logic programs in Lin and Shoham's logic of GK, a nonmonotonic modal logic that has been shown to include as special cases bot...
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We first embed Pearce's equilibrium logic and Ferraris's propositional general logic programs in Lin and Shoham's logic of GK, a nonmonotonic modal logic that has been shown to include as special cases both Reiter's default logic in the propositional case and Moore's autoepistemic logic. From this embedding, we obtain a mapping from Ferraris's propositional general logic programs to circumscription, and show that this mapping can be used to check the strong equivalence between two propositional logic programs in classical logic. We also show that Ferraris's propositional general logic programs can be extended to the first-order case, and our mapping from Ferraris's propositional general logic programs to circumscription can be extended to the first-order case as well to provide a semantics for these first-order general logic programs. (C) 2010 Elsevier B.V. All rights reserved.
The DLVHEX system implements the hex-semantics, which integrates answer set programming (ASP) with arbitrary external sources. Since its first release ten years ago, significant advancements were achieved. Most import...
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The DLVHEX system implements the hex-semantics, which integrates answer set programming (ASP) with arbitrary external sources. Since its first release ten years ago, significant advancements were achieved. Most importantly, the exploitation of properties of external sources led to efficiency improvements and flexibility enhancements of the language, and technical improvements on the system side increased user's convenience. In this paper, we present the current status of the system and point out the most important recent enhancements over early versions. While existing literature focuses on theoretical aspects and specific components, a bird's eye view of the overall system is missing. In order to promote the system for real-world applications, we further present applications which were already successfully realized on top of DLVHEX.
Causal discovery algorithms can induce some of the causal relations from the data, commonly in the form of a causal network such as a causal Bayesian network. Arguably however, all such algorithms lack far behind what...
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ISBN:
(纸本)9781450342322
Causal discovery algorithms can induce some of the causal relations from the data, commonly in the form of a causal network such as a causal Bayesian network. Arguably however, all such algorithms lack far behind what is necessary for a true business application. We develop an initial version of a new, general causal discovery algorithm called ETIO with many features suitable for business applications. These include (a) ability to accept prior causal knowledge (e.g., taking senior driving courses improves driving skills), (b) admitting the presence of latent confounding factors, (c) admitting the possibility of (a certain type of) selection bias in the data (e.g., clients sampled mostly from a given region), (d) ability to analyze data with missing-by-design (i.e., not planned to measure) values (e.g., if two companies merge and their databases measure different attributes), and (e) ability to analyze data from different interventions (e.g., prior and posterior to an advertisement campaign). ETIO is an instance of the logical approach to integrative causal discovery that has been relatively recently introduced and enables the solution of complex reverse-engineering problems in causal discovery. ETIO is compared against the state-of-the-art and is shown to be more effective in terms of speed, with only a slight degradation in terms of learning accuracy, while incorporating all the features above. The code is available on the *** website.
This paper introduces the agent platform HumanSim, a combination of the BDI-paradigm and answer set programming (ASP), to simulate entities in three-dimensional virtual environments. We show how ASP can be used to (i)...
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ISBN:
(纸本)9783319458892;9783319458885
This paper introduces the agent platform HumanSim, a combination of the BDI-paradigm and answer set programming (ASP), to simulate entities in three-dimensional virtual environments. We show how ASP can be used to (i) annotate a virtual three-dimensional world and (ii) to model the goal selection behavior of a BDI agent. Using this approach it is possible to model the agent domain and its behavior - reactive or foresighted - with ASP. To demonstrate the practical use of HumanSim, we present a three-dimensional planning and simulation application, in which worker agents are driven by HumanSim in the shop floor domain. Furthermore, we show the results of an evaluation of HumanSim in the former mentioned simulation application.
TropICAL is a Domain Specific Language (DSL) for the description of abstract legal policies. Taking inspiration from narrative tropes, our DSL enables the creation of component "policies" that may be reused ...
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ISBN:
(纸本)9781614997269;9781614997252
TropICAL is a Domain Specific Language (DSL) for the description of abstract legal policies. Taking inspiration from narrative tropes, our DSL enables the creation of component "policies" that may be reused between case descriptions. These components are compiled to social institutions, which are realised in answer set programming (ASP) code. In this way, the actions of defendant and plaintiff take the shape of a story which must conform to the rules in the ASP description. We propose the use of our DSL in a tool designed for lawyers to generate arguments for the argumentation process.
The DLVHEX system implements the hex-semantics, which integrates answer set programming (ASP) with arbitrary external sources. Since its first release ten years ago, significant advancements were achieved. Most import...
详细信息
The DLVHEX system implements the hex-semantics, which integrates answer set programming (ASP) with arbitrary external sources. Since its first release ten years ago, significant advancements were achieved. Most importantly, the exploitation of properties of external sources led to efficiency improvements and flexibility enhancements of the language, and technical improvements on the system side increased user's convenience. In this paper, we present the current status of the system and point out the most important recent enhancements over early versions. While existing literature focuses on theoretical aspects and specific components, a bird's eye view of the overall system is missing. In order to promote the system for real-world applications, we further present applications which were already successfully realized on top of DLVHEX.
answer set programming (ASP) under the stable model semantics supports various language constructs which can be used to express the same realities in syntactically different, but semantically equivalent ways. However,...
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ISBN:
(纸本)9783319460734;9783319460727
answer set programming (ASP) under the stable model semantics supports various language constructs which can be used to express the same realities in syntactically different, but semantically equivalent ways. However, these equivalent programs may not perform equally well. This is because performance depends on the underlying solver implementations that may treat different language constructs differently. As performance is very important for the successful application of ASP in real-life domains, knowledge about the mutual interchangeability and performance of ASP language constructs is crucial for knowledge engineers. In this article, we present an investigation on how the usage of different language constructs affects the performance of stateof-the-art solvers and grounders on benchmark problems from the ASP competition. Hereby, we focus on constructs used to express disjunction or choice, classical negation, and various aggregate functions. Some interesting effects of language constructs on solving performance are revealed.
Motivated by the declarative modeling paradigm for data mining, we report on our experience in modeling and solving relational query and graph mining problems with the IDP system, a variation on the answerset program...
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ISBN:
(数字)9783319405667
ISBN:
(纸本)9783319405667;9783319405650
Motivated by the declarative modeling paradigm for data mining, we report on our experience in modeling and solving relational query and graph mining problems with the IDP system, a variation on the answer set programming paradigm. Using IDP or other ASPlanguages for modeling appears to be natural given that they provide rich logical languages for modeling and solving many search problems and that relational query mining (and ILP) is also based on logic. Nevertheless, our results indicate that second order extensions to these languages are necessary for expressing the model as well as for efficient solving, especially for what concerns subsumption testing. We propose such second order extensions and evaluate their potential effectiveness with a number of experiments in subsumption as well as in query mining.
many of the current policy-based management systems implement policies that depend on dynamic operational environment contexts. The existing formal-based approaches for enforcing security policies are mainly expressed...
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ISBN:
(纸本)9781467388450
many of the current policy-based management systems implement policies that depend on dynamic operational environment contexts. The existing formal-based approaches for enforcing security policies are mainly expressed using first-order logic. A major drawback of using first-order logic in implementing dynamic policies is that new observations cannot override previously inferred consequences. In fact, a security system whose enterprise policies are implemented using first-order logic is required to have complete access to data in advance in order to be able to perform an informed reasoning and enforce restricting policies. As a major problem, the systems designed based on these first order logic-based approaches are often static, inflexible, and hard to manage and scale. This paper introduces an approach for expressing and enforcing adaptive access control policies dynamically. The paper presents a non-monotonic formal approach based on answer set programming where default policies are explicitly separated from context-dependent and exception policies that often occur in dynamic systems and in particular when the required context data are unavailable ahead of time. The results of presented case study demonstrate the flexibility of the proposed approach compared to the first order logic-based context-sensitive approaches as implemented in Organizational-Based Access Control (ORBAC) model.
Geographical information systems are ones of the most important application areas of belief revision. Recently, Wurbel and colleagues (Proceedings of the seventh international conference about principles of knowledge ...
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Geographical information systems are ones of the most important application areas of belief revision. Recently, Wurbel and colleagues (Proceedings of the seventh international conference about principles of knowledge representation and reasoning, KR2000, pp. 505-516, 2000) have applied the so-called "removed sets revision" (RSR) to the problem of assessment of water heights in a flooded valley. The application was partially satisfactory since only a small part of the valley has been handled. This paper goes one step further, and proposes an extension of (RSR) called "Prioritized Removed sets Revision" (PRSR). We show that (PRSR) performed using answer set programming makes possible to solve a practical revision problem provided by a real application in the framework of geographical information system (GIS). We first show how PRSR can be encoded into a logic program with answerset semantics, we then present an adaptation of the smodels system devoted to efficiently compute the answersets in order to perform PRSR. The experimental study shows that the answer set programming approach gives better results than previous implementations of RSR and in particular it allows to handle the whole valley. Lastly, some experimental studies comparing our encoding with implementations based on SAT-solvers are also provided.
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