Fundamenta Informaticae - Volume 85, issue 1-4

Authors: Gomolińska, Anna

Article Type: Research Article

Abstract: In this article we discuss judgment of satisfiability of formulas of a knowledge representation language as an object classification task. Our viewpoint is that of the rough set theory (RST), and the descriptor language for Pawlak's information systems of a basic kind is taken as the study case. We show how certain analogy-based methods can be employed to judge satisfiability of formulas of that language.

Keywords: satisfiability of formulas, valuation, object classification, Pawlak's information system, descriptor language, analogy-based reasoning

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 139-153, 2008

Authors: Góra, Grzegorz | Kruczek, Piotr | Skowron, Andrzej | Bazan, Jan G. | Bazan-Socha, Stanisława | Pietrzyk, Jacek J.

Article Type: Research Article

Abstract: We discuss medical treatment planning in the context of case-based planning, where plans (of treatment) are treated as complex decisions. A plan for a particular case is constructed from known plans for similar training examples. In order to evaluate and improve the prediction quality of complex decisions, we use a method for approximation of similarity measure between plans. The method makes it possible to transform the acquired domain knowledge about similarities of plans, expressed by medical …experts in natural language, to a low level language understandable by the system. To accomplish this task, we developed a method for approximation of the ontology of concepts expressed by medical experts. We present two applications of the ontology approximation, namely, for approximation of similarity between patient histories and for approximation of compatibility of patient histories with planned therapies. Next, we use these concept approximations to define two measures on which are based two methods for (plan) therapy prediction. The article includes results of experiments with these methods performed on medical data obtained from Neonatal Intensive Care Unit, First Department of Pediatrics, Polish-American Institute of Pediatrics, Collegium Medicum, Jagiellonian University, Krak?ow, Poland. The experiments are pertained to the identification of infants' death risk caused by respiratory failure. Show more

Keywords: automated planning, ontology of concepts, respiratory failure, rough sets, ontology approximation, similarity relation approximation

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 155-172, 2008

Authors: Gruska, Damas P.

Article Type: Research Article

Abstract: A formal model for description of probabilistic timing attacks is presented and studied. It is based on a probabilistic timed process algebra, on observations (mappings which make visible only a part of system behavior) and on an information flow. The resulting security properties are studied and compared with other security concepts.

Keywords: probabilistic timed process algebras, timing attacks, information flow, opacity, security

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 173-187, 2008

Authors: Gruska, Damas P. | Maggiolo–Schettini, Andrea | Milazzo, Paolo

Article Type: Research Article

Abstract: Communicating Hierarchical Transaction-based Timed Automata have been introduced to model systems performing long–running transactions. Here, for these automata a security concept is introduced, which is based on a notion of opacity and on the assumption that an attacker can not only observe public system activities, but also cause abortion of some of them. Different intruder capabilities as well as different kinds of opacity are defined and the resulting security properties are investigated. Security of long–running …transactions is defined by the mentioned notion of opacity and conditions for compositionality are established. Show more

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 189-203, 2008

Authors: Grzymala-Busse, Jerzy W. | Rz�sa, Wojciech

Article Type: Research Article

Abstract: In this paper we discuss approximation spaces that are useful for studying local lower and upper approximations. Set definability and properties of the approximation space, including best approximations, are considered as well. Finding best approximations is a NP-hard problem. Finally, we present LEM2-like algorithms for determining local lower and upper coverings for a given incomplete data set. Lower and upper approximations, associated with these coverings, are sub-optimal.

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 205-217, 2008

Authors: van Hee, Kees | Serebrenik, Alexander | Sidorova, Natalia

Article Type: Research Article

Abstract: State of the art information system commonly record events in log files, also known as audit trails. Moreover, business processes often go beyond the sole recording the events and base decisions on the events observed in the past. To model such processes we extend the basic Petri net framework with the notion of history by associating tokens with histories, adding guards evaluated on the history to the transitions and mapping arcs to expressions involving histories. Guards …and arc expressions can involve data associated with the transitions. Show more

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 219-234, 2008

Authors: Janowska, Agata | Janowski, Paweł | Wróblewski, Dobiesław

Article Type: Research Article

Abstract: The aim of this work is to describe the translation from Intermediate Language, one of the input formalisms of the model checking platform VerICS, to timed automata with discrete data and to compare it with the translation to classical timed automata. The paper presents syntax and semantics of both formalisms, the translation rules as well as a simple example.

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 235-248, 2008

Authors: Jankowski, Andrzej | Peters, James F. | Skowron, Andrzej | Stepaniuk, Jaroslaw

Article Type: Research Article

Abstract: The problem considered in this paper is the evaluation of perception as a means of optimizing various tasks. The solution to this problem hearkens back to early research on rough set theory and approximation. For example, in 1982, Ewa Orłowska observed that approximation spaces serve as a formal counterpart of perception. In this paper, the evaluation of perception is at the level of approximation spaces. The quality of an approximation space relative to a given approximated …set of objects is a function of the description length of an approximation of the set of objects and the approximation quality of this set. In granular computing (GC), the focus is on discovering granules satisfying selected criteria. These criteria take inspiration from the minimal description length (MDL) principle proposed by Jorma Rissanen in 1983. In this paper, the role of approximation spaces in modeling compound granules satisfying such criteria is discussed. For example, in terms of approximation itself, this paper introduces an approach to function approximation in the context of a reinterpretation of the rough integral originally proposed by Zdzisław Pawlak in 1993. We also discuss some other examples of compound granule discovery problems that are related to compound granules representing process models and models of interaction between processes or approximation of trajectories of processes. All such granules should be discovered from data and domain knowledge. The contribution of this article is a proposed solution approach to evaluating perception that provides a basis for optimizing various tasks related to discovery of compound granules representing rough integrals, process models, their interaction, or approximation of trajectories of discovered models of processes. Show more

Keywords: Approximation space, description, function approximation, granule, granular computing, perception, quality of an approximation space, rough integral

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 249-265, 2008

Authors: Jantzen, Matthias | Kudlek, Manfred | Zetzsche, Georg

Article Type: Research Article

Abstract: This paper presents results regarding the various relations among the language classes defined by Concurrent Finite Automata, relations to other language classes, as well as decidability and closure properties.

Keywords: Finite automata, Petri nets, language classes

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 267-280, 2008

Authors: Jółkowska, Joanna | Ochmański, Edward

Article Type: Research Article

Abstract: We propose a trace-based approach to description behaviours of concurrent systems. First, we define the independency relation induced by arbitrary transition system, forming this way an asynchronous transition system. Then we introduce the notion of traceability of transition systems and study some decision problems, related to computing independency and deciding traceability for basic classes of Petri nets. Main results: traceability is decidable for place/transition nets and undecidable in broader classes of nets …– inhibitor, reset and transfer nets. Show more

Citation: Fundamenta Informaticae, vol. 85, no. 1-4, pp. 281-295, 2008