TY - JOUR
T1 - Computing Inconsistency Measure based on Paraconsistent Semantics
Y1 - 2011
A1 - Yue Ma
A1 - Guilin Qi
A1 - Pascal Hitzler
AB - Measuring 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.
ER -
TY - JOUR
T1 - Computational Complexity and Anytime Algorithm for Inconsistency Measurement
JF - International Journal of Software and Informatics
Y1 - 2010
A1 - Yue Ma
A1 - Guilin Qi
A1 - Guohui Xiao
A1 - Pascal Hitzler
A1 - Zuoquan Lin
KW - algorithm
KW - computational complexity
KW - inconsistency measurement
KW - multi-valued logic
AB - Measuring 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.
ER -
TY - CONF
T1 - An Anytime Algorithm for Computing Inconsistency Measurement
T2 - Third International Conference, KSEM 2009
Y1 - 2009
A1 - Yue Ma
A1 - Guilin Qi
A1 - Guohui Xiao
A1 - Zuoquan Lin
A1 - Pascal Hitzler
AB - Measuring 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.
JA - Third International Conference, KSEM 2009
ER -
TY - CONF
T1 - A Forgetting-based Approach for Handling Inconsistency in Distributed Ontologies
Y1 - 2008
A1 - Guilin Qi
A1 - Yimin Wang
A1 - Peter Haase
A1 - Pascal Hitzler
AB - In 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.
PB - 5th European Semantic Web Conference, ESWC08
ER -
TY - CONF
T1 - An Algorithm for Computing Inconsistency Measurement by Paraconsistent Semantics
T2 - Proceedings of Ninth European Conference on Symbolic and Quanlitative Approaches to Reasoning with Uncertainty
Y1 - 2007
A1 - Yue Ma
A1 - Guilin Qi
A1 - Zuoquan Lin
A1 - Pascal Hitzler
AB - Measuring 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.
JA - Proceedings of Ninth European Conference on Symbolic and Quanlitative Approaches to Reasoning with Uncertainty
CY - Hammamet,Tunisia
ER -
TY - CONF
T1 - Measuring Inconsistency for Description Logics Based on Paraconsistent Semantics
T2 - Ninth European Conference on Symbolic and Quanlitative Approaches to Reasoning with Uncertainty
Y1 - 2007
A1 - Yue Ma
A1 - Guilin Qi
A1 - Zuoquan Lin
A1 - Pascal Hitzler
AB - In 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.
JA - Ninth European Conference on Symbolic and Quanlitative Approaches to Reasoning with Uncertainty
CY - Hammamet, Tunisia
ER -
TY - CONF
T1 - Measuring Inconsistency for Description Logics Based on Paraconsistent Semantics
Y1 - 2007
A1 - Yue Ma
A1 - Guilin Qi
A1 - Pascal Hitzler
A1 - Zuoquan Lin
AB - In 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.
PB - the 2007 International Workshop on Description Logics (DL-2007)
ER -