Contents & Abstracts, Schedae Informaticae, Issue 13 (2004)

Violeta Felea , Richard Olejnik , Bernard Toursel , ADAJ: a Java Distributed Environment for Easy Programming Design and Efficient Execution, pp. 9-36

Abstract.  In this paper we present a platform, ADAJ (Adaptive Distributed Applications in Java), that we have developed for distributed applications in Java over a cluster of computers. The objective of this platform is to facilitate the application design and to efficiently use the computing power. ADAJ offers both a programming and execution environment. The programming environment simplifies the user programming effort and offers a MIMD/SPMD programming model style. Our approach relies on the concept of distributed collections, grouping fragmented objects and on asynchronous calls.
The ADAJ execution environment supports irregularities during the evolution of the application and in the availabilities of resources. We present the architecture and the tools we have developed: object observation and load balancing mechanisms. The observation mechanism allows to estimate the JVM load. The load balancing mechanism dynamically adapts the execution according to this information. We present estimation measures on two different applications, so that to evaluate the benefits and the overhead of ADAJ.

Keywords. methodology of programming, parallelism and distribution, object observation, dynamic load balancing, Java computing.

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Krzysztof Atłasiewicz , Substring Languages, pp. 37-64

Abstract.  This paper investigates the concept of substring languages as an alternative to the traditional parsing scheme. Practical grounds are also presented. Then the properties of substring languages are investigated. The paper proposes the most rudimentary characteristics of substring languages and relations of this concept to classes: and . Finally, the map of problem solutions in substring sense is presented.

Keywords. syntactic pattern recognition, formal languages and automata.

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Andrzej Bielecki , Igor T. Podolak , Marzena Bielecka, A Neuronal Algorithm of Nonlinear Regression, pp. 65-81

Abstract.  This article is devoted to the comparison between two alternative approaches to the economic models creation and to the estimation of their parameters. The first approach is to create a multiple regression model whereas the second one is to use neural modeling. Both methods are applied to estimation of an exemplary econometric model.

Keywords. artificial neuronal networks, nonlinear regression.

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Janusz Jurek , The Object-oriented Architecture of the Syntactic Pattern-recognition System Based on GDPLL(k)
Grammars, pp. 83-102

Abstract.  The syntactic pattern recognition model based on GDPLL(k) grammars has been proposed as an efficient tool for inference support in diagnostic and control expert systems. In this paper we discuss the software engineering aspect of the syntactic pattern recognition (sub)system. The architecture of the system should allow to embed the system in real-time environments, accumulate knowledge about the environment, and flexible react to the changes in the environment. The object-oriented approach has been applied to design the system, and the Unified Modeling Language has been used for the specification of the software model. In the paper we present the model and its practical applications.

Keywords. syntactic pattern recognition, context sensitive languages, parsing, grammatical inference, object-oriented approach, software engineering.

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Piotr Kalita , Shell Models of the Artery Wall, pp. 103-122

Abstract.  In this paper we present different shell models and discuss their applicability to model the mechanical behavior of arterial walls. Presented models are: stationary and evolutionary, linear and nonlinear, membrane dominated and bending dominated. Special focus is put on the physically nonlinear stationary models which were first presented by the author. We give the well posedness results for the physically nonlinear stationary problem and linear nonstationary problem. We also discuss the numerical methods for solving the presented equations for the three dimensional field of displacement of the middle surface of the wall. Finally we give some simple computational examples.

Keywords. biomechanics, finite elements, Koiter shells.

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Alexander Meduna , Martin Vitek , New Language Operations in Formal Language Theory, pp. 123-150

Abstract.  Stringology represents a modern part of the formal language theory, which deals with strings, languages and operations on them. It introduces many new language operations, which can be divided into two groups – insertion and deletion operations. Some of these operations are described. This paper presents these operations and some of their properties. Especially, closure properties are studied here. New algorithms that construct finite automata accepting languages resulting from some of these operations are described here. We actually demonstrate by designing these algorithms, that the family of regular languages is closed under these operations.

Keywords. Stringology, sequential insertion, parallel insertion, scattered sequential insertion, sequential deletion, parallel deletion, scattered sequential deletion, finite automata, closure properties.

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Ryszard Szupiluk , Piotr Wojewnik , Tomasz Ząbkowski , Independent Component Analysis for Modelling Improvement, pp. 151-164

Abstract.  A common problem encountered in such disciplines as statistics, data analysis, signal processing, data mining and time series analysis is finding a suitable model to explore existing dependencies. There are many models with different advantages and it happens that different good criteria indicate different models as an optimal solution. We need good criteria to choose the best model. But how to choose the best criterion? To avoid this disadvantage we propose an Independent Component Analysis for adopting many solutions from a large set of competitive models. Such a transformation seems to capture the essential structure of data solutions in many applications.

Keywords. data mining, Independent Component Analysis, model combination.

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Edward Szczypka , Object Complexity, pp. 165-177

Abstract.  The publications and sources concerning the complexity of algorithms in respect of the complexity of input data are rather scarce, even though it is quite obvious that the complexity of algorithms strongly depends on the complexity of input data. At the same time expressions like 'almost all' or 'a certain part of' are commonly used in terminology concerning probabilistic algorithms and methods. In this paper we will attempt to take a closer look at what these expressions actually mean. Therefore we will aim to develop and systematize the theory of complexity functions.

Keywords. lambda-calculus, complexity function.

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