Fundamenta Informaticae - Volume 106, issue 1

Authors: Kamide, Norihiro | Wansing, Heinrich

Article Type: Research Article

Abstract: Inconsistency-tolerant reasoning and paraconsistent logic are of growing importance not only in Knowledge Representation, AI and other areas of Computer Science, but also in Philosophical Logic. In this paper, a new logic, paraconsistent linear-time temporal logic (PLTL), is obtained semantically from the linear-time temporal logic LTL by adding a paraconsistent negation. Some theorems for embedding PLTL into LTL are proved, and PLTL is shown to be decidable. A Gentzentype sequent calculus PLTω for PLTL is introduced, and the completeness and cut-elimination theorems for this calculus are proved. In addition, a display calculus δPLTω for PLTL is defined.

Keywords: paraconsistent logic, linear-time temporal logic, paraconsistent negation, embedding, sequent calculus, cut-elimination, display calculus

DOI: 10.3233/FI-2011-374

Citation: Fundamenta Informaticae, vol. 106, no. 1, pp. 1-23, 2011

Authors: Liu, Guohua | You, Jia-Huai

Article Type: Research Article

Abstract: Level mapping and loop formulas are two different means to justify and characterize answer sets for normal logic programs. Both of them specify conditions under which a supported model is an answer set. Though serving a similar purpose, in the past the two have been studied largely in isolation with each other. In this paper, we study level mapping and loop formulas for weight constraint and aggregate (logic) programs. We show that, for these classes of programs, loop formulas can be devised from level mapping characterizations. First, we formulate a level mapping characterization of stable models and show that it …leads to a new formulation of loop formulas for arbitrary weight constraint programs, without using any new atoms. This extends a previous result on loop formulas for weight constraint programs, where weight constraints contain only positive literals. Second, since aggregate programs are closely related to weight constraint programs, we further use level mapping to characterize the underlying answer set semantics based on which we formulate loop formulas for aggregate programs. The main result is that for aggregate programs not involving the inequality comparison operator, the dependency graphs can be built in polynomial time. This compares to the previously known exponential time method. Show more

Keywords: Logic programs, answer sets, weight constraints, aggregates, loop formulas

DOI: 10.3233/FI-2011-375

Citation: Fundamenta Informaticae, vol. 106, no. 1, pp. 25-43, 2011

Authors: Saha, Indrajit | Maulik, Ujjwal | Bandyopadhyay, Sanghamitra | Plewczynski, Dariusz

Article Type: Research Article

Abstract: In this article, a novel concept is introduced by using both unsupervised and supervised learning. For unsupervised learning, the problem of fuzzy clustering in microarray data as a multiobjective optimization is used, which simultaneously optimizes two internal fuzzy cluster validity indices to yield a set of Pareto-optimal clustering solutions. In this regards, a new multiobjective differential evolution based fuzzy clustering technique has been proposed. Subsequently, for supervised learning, a fuzzy majority voting scheme along with support vector machine is used to integrate the clustering information from all the solutions in the resultant Pareto-optimal set. The performances of the proposed clustering …techniques have been demonstrated on five publicly available benchmark microarray data sets. A detail comparison has been carried out with multiobjective genetic algorithm based fuzzy clustering, multiobjective differential evolution based fuzzy clustering, single objective versions of differential evolution and genetic algorithm based fuzzy clustering as well as well known fuzzy c-means algorithm. While using support vector machine, comparative studies of the use of four different kernel functions are also reported. Statistical significance test has been done to establish the statistical superiority of the proposed multiobjective clustering approach. Finally, biological significance test has been carried out using a web based gene annotation tool to show that the proposed integrated technique is able to produce biologically relevant clusters of coexpressed genes. Show more

Keywords: Fuzzy clustering, improved differential evolution, multiobjective optimization, Pareto-optimal, support vector machine

DOI: 10.3233/FI-2011-376

Citation: Fundamenta Informaticae, vol. 106, no. 1, pp. 45-73, 2011

Authors: Tang, Zhenjun | Wang, Shuozhong | Zhang, Xinpeng | Wei, Weimin

Article Type: Research Article

Abstract: Structural image features are exploited to construct perceptual image hashes in this work. The image is first preprocessed and divided into overlapped blocks. Correlation between each image block and a reference pattern is calculated. The intermediate hash is obtained from the correlation coefficients. These coefficients are finally mapped to the interval [0, 100], and scrambled to generate the hash sequence. A key component of the hashing method is a specially defined similarity metric to measure the “distance” between hashes. This similarity metric is sensitive to visually unacceptable alterations in small regions of the image, enabling the detection of small area …tampering in the image. The hash is robust against content-preserving processing such as JPEG compression, moderate noise contamination, watermark embedding, re-scaling, brightness and contrast adjustment, and low-pass filtering. It has very low collision probability. Experiments are conducted to show performance of the proposed method. Show more

Keywords: image hashing, tampering detection, content-based image retrieval, structural feature, similarity metric, watermarking

DOI: 10.3233/FI-2011-377

Citation: Fundamenta Informaticae, vol. 106, no. 1, pp. 75-91, 2011

Authors: Wakulicz-Deja, Alicja | Przybyła-Kasperek, Małgorzata

Article Type: Research Article

Abstract: The paper presents the process of taking global decisions on the basis of the knowledge of local decision systems, in which sets of conditional attributes are different but not necessarily disjoint. We propose the organization of local decision systems into a multi-agent system with a hierarchical structure. The structure of multi-agent systems and the theoretical aspects of the organization of the system are presented. An editing and a condensing algorithm have been used in the process of global decision making. Also a density-based algorithm has been used in the process of taking global decisions to resolve conflicts. Furthermore, the paper …presents the results of experiments conducted using some data sets from UCI repository. Show more

Keywords: decision system, global decision, editing algorithm, condensing algorithm, density-based algorithm

DOI: 10.3233/FI-2011-378

Citation: Fundamenta Informaticae, vol. 106, no. 1, pp. 93-117, 2011