Unification is one of the fundamental algorithms of logic programming. It is fundamentally a pattern matching process which includes variables that match anything. This paper explores various alternatives for the APL2...
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Answer Set programming (ASP) is a powerful declarative programming paradigm that has been successfully applied to many different domains. Recently, ASP has also proved successful for hard optimization problems like co...
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Answer Set programming (ASP) is a powerful declarative programming paradigm that has been successfully applied to many different domains. Recently, ASP has also proved successful for hard optimization problems like course timetabling and travel allotment. In this paper, we approach another important task, namely, the shift design problem, aiming at an alignment of a minimum number of shifts in order to meet required numbers of employees (which typically vary for different time periods) in such a way that over- and understaffing is minimized. We provide an ASP encoding of the shift design problem, which, to the best of our knowledge, has not been addressed by ASP yet. Our experimental results demonstrate that ASP is capable of improving the best known solutions to some benchmark problems. Other instances remain challenging and make the shift design problem an interesting benchmark for ASP-based optimization methods.
Background: Clinical protocols and guidelines have been considered as a major means to ensure that cost-effective services are provided at the point of care. Recently, the computerisation of clinical guidelines has at...
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Background: Clinical protocols and guidelines have been considered as a major means to ensure that cost-effective services are provided at the point of care. Recently, the computerisation of clinical guidelines has attracted extensive research interest. Many languages and frameworks have been developed. Thus far, however, an enactment mechanism to facilitate decentralised guideline execution has been a largely neglected line of research. It is our contention that decentralisation is essential to maintain a high-performance system in pervasive health care scenarios. In this paper, we propose the use of Lightweight Coordination Calculus (LCC) as a feasible solution. LCC is a light-weight and executable process calculus that has been used successfully in multi-agent systems, peer-to-peer (p2p) computer networks, etc. In light of an envisaged pervasive health care scenario, LCC, which represents clinical protocols and guidelines as message-based interaction models, allows information exchange among software agents distributed across different departments and/or hospitals. Results: We outlined the syntax and semantics of LCC;proposed a list of refined criteria against which the appropriateness of candidate clinical guideline modelling languages are evaluated;and presented two LCC interaction models of real life clinical guidelines. Conclusions: We demonstrated that LCC is particularly useful in modelling clinical guidelines. It specifies the exact partition of a workflow of events or tasks that should be observed by multiple "players" as well as the interactions among these "players". LCC presents the strength of both process calculi and Horn clauses pair of which can provide a close resemblance of logic programming and the flexibility of practical implementation.
We show how Finite Model Computation (FMC) of first-order theories can efficiently and transparently be solved by taking advantage of an extension of Answer Set programming, called incremental Answer Set programming (...
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ISBN:
(纸本)9781577355120
We show how Finite Model Computation (FMC) of first-order theories can efficiently and transparently be solved by taking advantage of an extension of Answer Set programming, called incremental Answer Set programming (iASP). The idea is to use the incremental parameter in iASP programs to account for the domain size of a model. The FMC problem is then successively addressed for increasing domain sizes until an answer set, representing a finite model of the original first-order theory, is found. We developed a system based on the iASP solver iClingo and demonstrate its competitiveness.
Expert system technology becomes more and more important for next generation computer systems. A rule base is a widely used approach to construct an expert system, where knowledge and expertise are represented as prod...
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Expert system technology becomes more and more important for next generation computer systems. A rule base is a widely used approach to construct an expert system, where knowledge and expertise are represented as production rules. However, due to the growth of rule base usage, the scale of rule base is increasing and hence many management related issues arise. By considering not only the structural relatedness between rules but also the semantic relatedness of rules, RP-MES is proposed combining both rule base partitioning mechanism and meta-rule construction mechanism to solve these issues in this paper. An Intrusion Detection prototype System is also designed and implemented based on RP-MES, and some experiments have been done to evaluate the system performance. The experimental results show that RP-MES can improve the accuracy of the inference results, and that the performance of RP-MES is better than that of original rule base without partitioning.
It has been recognised that better programming tools are required to support the logic programming paradigm of Answer Set programming (ASP), especially when larger scale applications need to be developed. In order to ...
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It has been recognised that better programming tools are required to support the logic programming paradigm of Answer Set programming (ASP), especially when larger scale applications need to be developed. In order to meet this demand, the aspects of programming in ASP that require better support need to be investigated, and suitable tools to support them identified and implemented. In this paper we detail an exploratory development approach to implementing an Integrated Development Environment (IDE) for ASP, the AnsProlog* programming Environment (APE). APE is implemented as a plug-in for the Eclipse platform. Given that an IDE is itself composed of a set of programming tools, this approach is used to identify a set of tool requirements for ASP, together with suggestions for improvements to existing tools and programming practices.
We study abduction in First Order Horn logic theories where all atoms can be abduced and we are looking for preferred solutions with respect to three objective functions: Cardinality minimality, coherence, and weighte...
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We study abduction in First Order Horn logic theories where all atoms can be abduced and we are looking for preferred solutions with respect to three objective functions: Cardinality minimality, coherence, and weighted abduction. We represent this reasoning problem in Answer Set programming (ASP), in order to obtain a flexible framework for experimenting with global constraints and objective functions, and to test the boundaries of what is possible with ASP. Realizing this problem in ASP is challenging as it requires value invention and equivalence between certain constants, because the Unique Names Assumption does not hold in general. To permit reasoning in cyclic theories, we formally describe fine-grained variations of limiting Skolemization. We identify term equivalence as a main instantiation bottleneck, and improve the efficiency of our approach with on-demand constraints that were used to eliminate the same bottleneck in state-ofthe- art solvers. We evaluate our approach experimentally on the ACCEL benchmark for plan recognition in Natural Language Understanding. Our encodings are publicly available, modular, and our approach is more efficient than state-of-the-art solvers on the ACCEL benchmark.
Smart environments powered by the Internet of Things aim at improving our daily lives by automatically tuning ambient parameters (e.g. temperature, interior light) and by achieving energy savings through self-managing...
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We show that the concept of strong equivalence of logic programs can be generalized to an abstract algebraic setting of operators on complete lattices. Our results imply characterizations of strong equivalence for sev...
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We show that the concept of strong equivalence of logic programs can be generalized to an abstract algebraic setting of operators on complete lattices. Our results imply characterizations of strong equivalence for several nonmonotonic logics including logic programming with aggregates, default logic and a version of autoepistemic logic.
This paper focuses on the inference of modes for which a logic program is guaranteed to *** generalizes traditional termination analysis where an analyzer tries to verify termination for a specified *** contribution i...
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