Informatica - Volume 6, issue 2

Authors: Alastruey, Carlos F.

Article Type: Research Article

Abstract: This paper investigates the progress made in the field of dynamic systems with delays over the last two decades. In particular, it is focused on the simulation and control techniques, which include also modelling, numerical solvability and stabilization procedures.

Keywords: point and distributed delays, stabilizability, state-space

DOI: 10.3233/INF-1995-6201

Citation: Informatica, vol. 6, no. 2, pp. 123-166, 1995

Authors: Lipeika, Antanas | Lipeikienė, Joana

Article Type: Research Article

Abstract: The use of vector quantization for speaker identification is investigated. This method differs from the known methods in that the number of centroids is not doubled but increases by 1 at every step. This enables us to obtain identification results at any number of centroids. This method is compared experimentally with the method (Lipeika and Lipeikienė, 1993a, 1993b), where feature vectors of investigative and comparative speakers are compared directly.

Keywords: speaker identification, likelihood ratio distance, vector quantization

DOI: 10.3233/INF-1995-6202

Citation: Informatica, vol. 6, no. 2, pp. 167-180, 1995

Authors: Maskeliūnas, Saulius

Article Type: Research Article

Abstract: Rule-based systems are usually interpreted as a shallow expert systems realization tool. The paper analyses how the applicability of production rules can be extended using the proposed rule base structuring discipline. Its main constructions are rule grouping according to elementary aspects of investigation, and decomposition of actions. In addition, the rule cycle construction is used for discrete time simulation tasks. The proposed method is illustrated by 2 applications: the expert subsystem for a database, and the simulator of a water heater.

Keywords: knowledge representation, rule base structuring, forward and backward chaining, rule-based simulation

DOI: 10.3233/INF-1995-6203

Citation: Informatica, vol. 6, no. 2, pp. 181-192, 1995

Authors: Mockus, Jonas

Article Type: Research Article

Abstract: We apply some concepts of Information-Based Complexity (IBC) to global and discrete optimization. We assume that only partial information on the objective is available. We gather this partial information by observations. We use the traditional IBC definitions and notions while defining formal aspects of the problem. We use the Bayesian framework to consider less formal aspects, such as expert knowledge and heuristics. We extend the traditional Bayesian Approach (BA) including heuristics. We call that a Bayesian Heuristic Approach (BHA). We discuss how to overcome the computational difficulties using parallel computing. We illustrate the theoretical concepts by three examples: …by discrete problems of flow-shop scheduling and parameter grouping, and by a continuous problem of batch operations scheduling. Show more

Keywords: complexity, average, Bayesian, optimization, heuristic, global, discrete

DOI: 10.3233/INF-1995-6204

Citation: Informatica, vol. 6, no. 2, pp. 193-224, 1995

Authors: Montvilas, Algirdas Mykolas

Article Type: Research Article

Abstract: An algorithm for the sequential analysis of multivariate data structure is presented. The algorithm is based on the sequential nonlinear mapping of L -dimensional vectors from the L -hyperspace into a lower-dimensional (two-dimensional) vectors such that the inner structure of distances among the vectors is preserved. Expressions for the sequential nonlinear mapping are obtained. The mapping error function is chosen. Theoretical minimum amount of the very beginning simultaneously mapped vectors is obtained.

Keywords: dimensionality reduction, sequential nonlinear mapping, sequential detection of changes

DOI: 10.3233/INF-1995-6205

Citation: Informatica, vol. 6, no. 2, pp. 225-232, 1995

Authors: Tumasonis, Vladas

Article Type: Research Article

Abstract: The newest version of Turbo Pascal – Turbo Pascal 7.0 – is concentrately described in comparing with optimal language for programming teaching – Standard Pascal. Data types, control structures, procedures and functions, parameters, new directions of development are classified and discussed.

Keywords: programming languages, Pascal, Turbo Pascal, data types, control structures, procedures and functions, units, objects

DOI: 10.3233/INF-1995-6206

Citation: Informatica, vol. 6, no. 2, pp. 233-243, 1995