02040nas a2200121 4500008004100000245007000041210006900111520165400180100001201834700001501846700002001861856003701881 2011 eng d00aComputing Inconsistency Measure based on Paraconsistent Semantics0 aComputing Inconsistency Measure based on Paraconsistent Semantic3 aMeasuring inconsistency in knowledge bases has been recognized as an important problem in several research areas. Many methods have been proposed to solve this problem and a main class of them is based on some kind of paraconsistent semantics. However, existing methods suffer from two limitations: (i) they are mostly restricted to propositional knowledge bases; (ii) very few of them discuss computational aspects of computing inconsistency measures. In this article, we try to solve these two limitations by exploring algorithms for computing an inconsistency measure of first-order knowledge bases. After introducing a four-valued semantics for first-order logic, we define an inconsistency measure of a first-order knowledge base, which is a sequence of inconsistency degrees. We then propose a precise algorithm to compute our inconsistency measure. We show that this algorithm reduces the computation of the inconsistency measure to classical satisfiability checking. This is done by introducing a new semantics, named S[n]-4 semantics, which can be calculated by invoking a classical SAT solver. Moreover, we show that this auxiliary semantics also gives a direct way to compute upper and lower bounds of inconsistency degrees. That is, it can be easily revised to compute approximating inconsistency measures. The approximating inconsistency measures converge to the precise values if enough resources are available. Finally, by some nice properties of the S[n]-4 semantics, we show that some upper and lower bounds can be computed in P-time, which says that the problem of computing these approximating inconsistency measures is tractable.1 aMa, Yue1 aQi, Guilin1 aHitzler, Pascal uhttp://www.knoesis.org/node/159801495nas a2200205 4500008004100000245008100041210006900122300000900191520087500200653001401075653002901089653003001118653002301148100001201171700001501183700001701198700002001215700001701235856003701252 2010 eng d00aComputational Complexity and Anytime Algorithm for Inconsistency Measurement0 aComputational Complexity and Anytime Algorithm for Inconsistency a3-213 aMeasuring inconsistency degrees of inconsistent knowledge bases is an important problem as it provides context information for facilitating inconsistency handling. Many methods have been proposed to solve this problem and a main class of them is based on some kind of paraconsistent semantics. In this paper, we consider the computational aspects of inconsistency degrees of propositional knowledge bases under 4-valued semantics. We first give a complete analysis of the computational complexity of computing inconsistency degrees. As it turns out that computing the exact inconsistency degree is intractable, we then propose an anytime algorithm that provides tractable approximations of the inconsistency degree from above and below. We show that our algorithm satisfies some desirable properties and give experimental results of our implementation of the algorithm. 10aalgorithm10acomputational complexity10ainconsistency measurement10amulti-valued logic1 aMa, Yue1 aQi, Guilin1 aXiao, Guohui1 aHitzler, Pascal1 aLin, Zuoquan uhttp://www.knoesis.org/node/161801249nas a2200145 4500008004100000245006500041210006200106520081700168100001200985700001500997700001701012700001701029700002001046856003701066 2009 eng d00aAn Anytime Algorithm for Computing Inconsistency Measurement0 aAnytime Algorithm for Computing Inconsistency Measurement3 aMeasuring inconsistency degrees of inconsistent knowledge bases is an important problem as it provides context information for facilitating inconsistency handling. Many methods have been proposed to solve this problem and a main class of them is based on some kind of paraconsistent semantics. In this paper, we consider the computational aspects of inconsistency degrees of propositional knowledge bases under 4-valued semantics. We first analyze its computational complexity. As it turns out that computing the exact inconsistency degree is intractable, we then propose an anytime algorithm that provides tractable approximation of the inconsistency degree from above and below.We show that our algorithm satisfies some desirable properties and give experimental results of our implementation of the algorithm.1 aMa, Yue1 aQi, Guilin1 aXiao, Guohui1 aLin, Zuoquan1 aHitzler, Pascal uhttp://www.knoesis.org/node/124601005nas a2200145 4500008004100000245008500041210006900126260004900195520051000244100001500754700001600769700001700785700002000802856003700822 2008 eng d00aA Forgetting-based Approach for Handling Inconsistency in Distributed Ontologies0 aForgettingbased Approach for Handling Inconsistency in Distribut b5th European Semantic Web Conference, ESWC083 aIn the context of multiple distributed ontologies, we are often confronted with the problem of dealing with inconsistency. In this paper, we propose an approach for reasoning with inconsistent distributed ontologies based on *concept forgetting*.We firstly define *concept forgetting* in description logics.We then adapt the notions of recoveries and preferred recoveries in propositional logic to description logics. Two consequence relations are then defined based on the preferred recoveries.1 aQi, Guilin1 aWang, Yimin1 aHaase, Peter1 aHitzler, Pascal uhttp://www.knoesis.org/node/185201106nas a2200157 4500008004100000245008500041210006900126260002100195300001100216520062000227100001200847700001500859700001700874700002000891856003700911 2007 eng d00aAn Algorithm for Computing Inconsistency Measurement by Paraconsistent Semantics0 aAlgorithm for Computing Inconsistency Measurement by Paraconsist aHammamet,Tunisia a91-1023 aMeasuring inconsistency in knowledge bases has been recognized as an important problem in many research areas. Most of approaches proposed for measuring inconsistency are based on paraconsistent semantics. However, very few of them provide an algorithm for implementation. In this paper, we first give a four-valued semantics for first-order logic and then propose an approach for measuring the degree of inconsistency based on this four-valued semantics. After that, we propose an algorithm to compute the inconsistency degree by introducing a new semantics for first order logic, which is called S[n]-4 semantics.1 aMa, Yue1 aQi, Guilin1 aLin, Zuoquan1 aHitzler, Pascal uhttp://www.knoesis.org/node/121500841nas a2200145 4500008004100000245008500041210006900126260002200195520037700217100001200594700001500606700001700621700002000638856003700658 2007 eng d00aMeasuring Inconsistency for Description Logics Based on Paraconsistent Semantics0 aMeasuring Inconsistency for Description Logics Based on Paracons aHammamet, Tunisia3 aIn this paper, we present an approach for measuring inconsistency in a knowledge base.We first define the degree of inconsistency using a four-valued semantics for the description logic ALC. Then an ordering over knowledge bases is given by considering their inconsistency degrees. Our measure of inconsistency can provide important information for inconsistency handling.1 aMa, Yue1 aQi, Guilin1 aLin, Zuoquan1 aHitzler, Pascal uhttp://www.knoesis.org/node/121600887nas a2200145 4500008004100000245008500041210006900126260006800195520037700263100001200640700001500652700002000667700001700687856003700704 2007 eng d00aMeasuring Inconsistency for Description Logics Based on Paraconsistent Semantics0 aMeasuring Inconsistency for Description Logics Based on Paracons bthe 2007 International Workshop on Description Logics (DL-2007)3 aIn this paper, we present an approach for measuring inconsistency in a knowledge base.We first define the degree of inconsistency using a four-valued semantics for the description logic ALC. Then an ordering over knowledge bases is given by considering their inconsistency degrees. Our measure of inconsistency can provide important information for inconsistency handling.1 aMa, Yue1 aQi, Guilin1 aHitzler, Pascal1 aLin, Zuoquan uhttp://www.knoesis.org/node/1835