Fundamenta Informaticae - Volume 61, issue 2

Authors: Suraj, Zbigniew

Article Type: Other

Citation: Fundamenta Informaticae, vol. 61, no. 2, pp. i-ii, 2004

Authors: Moshov, Mikhail Ju. | Chikalov, Igor V.

Article Type: Research Article

Abstract: In the paper algorithms are considered which allow to optimize decision trees consecutively againsts relatively different criterions. For decision tables over an arbitrary infinite restricted information system [4], these algorithms have polynomial time complexity.

Keywords: decision trees, complexity measures, optimization

Citation: Fundamenta Informaticae, vol. 61, no. 2, pp. 87-96, 2004

Authors: Pancerz, Krzysztof | Suraj, Zbigniew

Article Type: Research Article

Abstract: The synthesis problem of concurrent systems has earlier been discussed in the literature using different types of formalisms. This paper presents a new method for discovery of asynchronous concurrent models from experimental tables by using a rough set approach. The proposed method can be applied to the automatic data model discovery. The algorithm for constructing asynchronous concurrent models is described in detail. As a model for concurrency the Coloured Petri Nets are used. Constructed asynchronous models …can be helpful to solving some problems arising in design of asynchronous digital systems or addressing of nodes in parallel systems. An example illustrates an application of the proposed approach in such problems. Show more

Keywords: information systems, rough sets, concurrency, asynchronous models, Coloured Petri Nets

Citation: Fundamenta Informaticae, vol. 61, no. 2, pp. 97-116, 2004

Authors: Pindur, Roman | Susmaga, Robert | Stefanowski, Jerzy

Article Type: Research Article

Abstract: In this paper we consider multiple criteria decision aid systems based on decision rules generated from examples. A common problem in such systems is the over-abundance of decision rules, as in many situations the rule generation algorithms produce very large sets of rules. This prolific representation of knowledge provides a great deal of detailed information about the described objects, but is appropriately difficult to interpret and use. One way of solving this problem is to aggregate …the created rules into more general ones, e.g. by forming rules of enriched syntax. The paper presents a generalization of elementary rule conditions into linear combinations. This corresponds to partitioning the preference-ordered condition space of criteria with non-orthogonal hyperplanes. The objective of this paper is to introduce the generalized rules into the multiple criteria classification problems and to demonstrate that these problems can be successfully solved using the introduced rules. The usefulness of the introduced solution is finally demonstrated in computational experiments with real-life data sets. Show more

Keywords: rough sets, knowledge discovery and representation, rule induction

Citation: Fundamenta Informaticae, vol. 61, no. 2, pp. 117-137, 2004

Authors: Stepaniuk, Jarosław | Hońko, Piotr

Article Type: Research Article

Abstract: The aim of this paper is to introduce and investigate an algorithm RSRL for finding first--order logic rules. Rough set methodology is used in the process of selecting literals which may be a part of a rule. The criterion of selecting a literal is as follows: only such a literal is selected, which added to the rule makes the rule discerning the most examples which were indiscernible so far.

Citation: Fundamenta Informaticae, vol. 61, no. 2, pp. 139-157, 2004

Authors: Susmaga, Robert

Article Type: Research Article

Abstract: One of the main notions in the Rough Sets Theory (RST) is that of a reduct. According to its classic definition, the reduct is a minimal subset of the attributes that retains some important properties of the whole set of attributes. The idea of the reduct proved to be interesting enough to inspire a great deal of research and resulted in introducing various reduct-related ideas and notions. First of all, depending on the character of the attributes …involved in the analysis, so called absolute and relative reducts can be defined. The more interesting of these, relative reducts, are minimal subsets of attributes that retain discernibility between objects belonging to different classes. This paper focuses on the topological aspects of such reducts, identifying some of their limitations and introducing alternative definitions that do not suffer from these limitations. The modified subsets of attributes, referred to as constructs, are intended to assist the subsequent inductive process of data generalisation and knowledge acquisition, which, in the context of RST, usually takes the form of decision rule generation. Usefulness of both reducts and constructs in this role is examined and evaluated in a massive computational experiment, which was carried out for a collection of real-life data sets. Show more

Keywords: rough sets theory, attribute reduction, indiscernibility and similarity relation

Citation: Fundamenta Informaticae, vol. 61, no. 2, pp. 159-181, 2004