In the past few years, several approaches for revision (and update) of logic programs have been studied. None of these however matched the generality and elegance of the original AGM approach to revision in classical ...
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ISBN:
(纸本)9783642405648
In the past few years, several approaches for revision (and update) of logic programs have been studied. None of these however matched the generality and elegance of the original AGM approach to revision in classical logic. One particular obstacle is the underlying nonmonotonicity of the semantics of logic programs. Recently however, specific revision operators based on the monotonic concept of SE-models (which underlies the answer-set semantics of logic programs) have been proposed. Basing revision of logic programs on sets of SE-models has the drawback that arbitrary sets of SE-models may not necessarily be expressed via a logic program. this situation is similar to the emerging topic of revision in fragments of classical logic. In this paper we show how nonetheless classical AGM-style revision can be extended to various classes of logic programs using the concept of SE-models. that is, we rephrase the AGM postulates in terms of logic programs, provide a semantic construction for revision operators, and then in a representation result show that these approaches coincide. this work is interesting because, on the one hand it shows how the AGM approach can be extended to a seemingly nonmonotonic framework, while on the other hand the formal characterization may provide guiding principles for the development of specific revision operators.
Unlike traditional web applications, current web applications called RIAs become powerful and useful by combining several technologies including markup languages, client-side script languages and web services. therefo...
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ISBN:
(纸本)9780889869431
Unlike traditional web applications, current web applications called RIAs become powerful and useful by combining several technologies including markup languages, client-side script languages and web services. therefore, it becomes more complicated to develop these applications and a number of stakeholders including designers and developers are required. It is reasonable to divide an application into several concerns (i.e., modules) to make the development effective, however, pieces of code to combine each concern prevent it. For example, designers design user interfaces with markup languages, e.g., HTML and developers implement application logic with script languages. then developers will often need to add code (e.g., event handlers) to connect the user interface and the logic so that this will become a single application. In this paper, we propose a client-side script language extension inspired by Aspect-Oriented programming, which is well-known concept to realize improved separation of concerns. this language extension mainly focuses on the complete separation between markup languages, which represent user interfaces, and script languages, which represent client-side logic. In addition, we provide a prototype implementation of an weaver, which combines modules before the execution.
In this paper we present possibilistic minimal models for possibilistic normal programs, we relate them to the possibilistic Cω logic, PCωL, and to minimal models of normal logic programs. Possibilistic stable model...
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We present an extension of GLukG, a logicthat was introduced in [8] as a three-valued logic under the name of G3′. GLukG is a paraconsistent logic defined in terms of 15 axioms, which serves as the formalism to defi...
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In this work, a proximity-based generic method for discovery of generalized knowledge is presented and implemented in the framework of a fuzzy logicprogramming language with a weak unification procedure that uses pro...
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ISBN:
(纸本)9783642386817
In this work, a proximity-based generic method for discovery of generalized knowledge is presented and implemented in the framework of a fuzzy logicprogramming language with a weak unification procedure that uses proximity relations to model uncertainty. this method makes use of the concept of lambda-block characterizing the notion of equivalence when working with proximity relations. When the universe of discourse is composed of concepts which are related by proximity, the sets of lambda-blocks extracted from that proximity relation can be seen as hierarchical sets of concepts grouped by abstraction level. then, each group (forming a lambda-block) can be labeled, with user help, by way of a more general descriptor in order to simulate a generalization process based on proximity. thanks to this process, the system can learn concepts that were unknown initially and reply queries that it was not able to answer. the novelty of this work is that it is the first time a method, with analogous features to the one aforementioned, has been implemented inside a fuzzy logicprogramming framework. In order to check the feasibility of the method we have developed a software tool which have been integrated into the Bousk similar to Prolog system.
Answer Set programming is a well-established paradigm of declarative programming in close relationship with other declarative formalisms such as SAT Modulo theories, Constraint Handling Rules, PDDL and many others. Si...
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ISBN:
(纸本)9783642405648
Answer Set programming is a well-established paradigm of declarative programming in close relationship with other declarative formalisms such as SAT Modulo theories, Constraint Handling Rules, PDDL and many others. Since its first informal editions, ASP systems are compared in the nowadays customary ASP Competition. the fourth ASP Competition, held in 2012/2013, is the sequel to previous editions and it was jointly organized by University of Calabria (Italy) and the Vienna University of Technology (Austria). Participants competed on a selected collection of benchmark problems, taken from a variety of research areas and real world applications. the Competition featured two tracks: the Model& Solve Track, held on an open problem encoding, on an open language basis, and open to any kind of system based on a declarative specification paradigm;and the System Track, held on the basis of fixed, public problem encodings, written in a standard ASP language.
In this paper we present a method for debugging XPath queries which has been implemented withthe fuzzy logic language MALP by using the FLOPER tool developed in our group. We describe how XPath expressions can be man...
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ISBN:
(纸本)9783642386817
In this paper we present a method for debugging XPath queries which has been implemented withthe fuzzy logic language MALP by using the FLOPER tool developed in our group. We describe how XPath expressions can be manipulated for obtaining a set of alternative queries matching a given XML document. For each new proposed query, we give a "chance degree" that represents an estimation on its deviation w.r.t. the initial expression. Our work is focused on providing to the programmers a repertoire of paths which can be used to retrieve answers.
Metabolic network reconstruction is of great biological relevance because it offers a way to investigate the metabolic behavior of organisms. However, reconstruction remains a difficult task at boththe biological and...
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ISBN:
(纸本)9783642405648
Metabolic network reconstruction is of great biological relevance because it offers a way to investigate the metabolic behavior of organisms. However, reconstruction remains a difficult task at boththe biological and computational level. Building on previous work establishing an ASP-based approach to this problem, we present a report from the field resulting in the discovery of new biological knowledge. In fact, for the first time ever, we automatically reconstructed a metabolic network for a macroalgae. We accomplished this by taking advantage of ASP's combined optimization and enumeration capacities. Both computational tasks build on an improved ASP problem representation, incorporating the concept of reversible reactions. Interestingly, optimization greatly benefits from the usage of unsatisfiable cores available in the ASP solver unclasp. Applied to Ectocarpus siliculosus, only the combination of unclasp and clasp allowed us to obtain a metabolic network able to produce all recoverable metabolites among the experimentally measured ones. Moreover, 70% of the identified reactions are supported by an homologous enzyme in Ectocarpus siliculosus, confirming the quality of the reconstructed network from a biological viewpoint.
We present Version 2 of system Cplus2ASP, which implements the definite fragment of action language C+. Its input language is fully compatible withthe language of the Causal Calculator Version 2, but the new system i...
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We have recently proposed a technique for generating thresholds (filters) useful for avoiding useless computations when executing fuzzy logic programs in a tabulated way. the method was conceived as a static preproces...
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ISBN:
(纸本)9783642386787
We have recently proposed a technique for generating thresholds (filters) useful for avoiding useless computations when executing fuzzy logic programs in a tabulated way. the method was conceived as a static preprocess practicable on program rules before being executed with our fuzzy thresholded tabulation principle, thus increasing the opportunities of prematurely disregarding those computation steps which are redundant (tabulation) or directly lead to non-significant solutions (thresholding). In this paper we reinforce the power of such static preprocess-which does not require the consumption of extra computational resources at execution time-by re-formulating it in terms of the fuzzy unfolding technique initially designed in our group for transforming and optimizing fuzzy logic programs.
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