Vol. 26 - Year 2001 Abstracts

No. 1

Z. Fryźlewicz, R. Gierusz:

Graphical interface design using XML


The article introduces a methodology for graphical user interface design basing on an interface specified in an XML document. The proposed solution in based on Java language constructs. The architecture and the processing of information are described. The proposed solution is scalable and rapidly extensible, and is intended to support the process of interface design for the needs of large and medium-sized applications.

B. Hnatkowska, M. Piasecki:

Conceptual modeling of user interface in object oriented methodologies


The paper proposes application of COOAD method of conceptual modeling of user interface in well-known object-oriented methodologies of software development like RUP or USDP. The main phases of user interface construction are presented and located in mentioned processes. The introduced ideas and notions are illustrated with a simple example.

A. Jarzębowicz, J. Górski:

Experimental comparison of UML-HAZOP inspection and non-strucutred interview


The paper describes an experiment conducted in the academic environment with participation of students from Gdansk University of Technology. The aim of the experiment was to compare two review techniques: inspection based on the UML-HAZOP method and a non-structured review. Effectiveness and efficiency of both methods were measured and compared. The paper presents the schedule, realisation and results of the experiment. An introduction to reviews and inspections as well as a brief description of the UML-HAZOP method are also included.

K. Drozdowski, J. Jarzemski, H. Krawczyk, M. Melzer, M. Smółka, B. Wiszniewski:

A cooperative model for implementing complex virtual enterprises


Authors strongly argue for the cooperative model of software development based on a virtual enterprise paradigm, where classic models such as waterfall or spiral may fail. Arguments have been supported with concrete evidence gathered during the recently concluded MEMORIAL IST-2001-33441 project funded by EU.

L. Madeyski, M. Stochmiałek:

Architectural design of modern web applications


Architectural design is about decisions which influence characteristics of arising system e.g. maintainability or scalability. Existing architectural frameworks, like MVC or PCMEF, allow building well-structured applications as a result of minimizing dependences between the system modules. Authors of this paper analysed these frameworks in the web application context. MVC and PCMEF appeared to be inspirations for the new XWA (eXtensible Web Architecture) architectural framework combining strengths of both frameworks and incorporating the idea of continuations into a separated controller. Additionally the detailed description of practical implementation of XWA on e-Informatyka portal example and guidelines for building web applications especially based on Apache Cocoon similar technologies are presented.

M. Szpyrka, T. Szmuc, P. Matyasik, W. Szmuc:

A formal approach to modelling of real-time systems using RTCP-nets


The paper deals with an application of formal methods for modelling of real-time systems. The main objective of this approach is to support development of these systems in order to ensure that the produced software artefacts are correct, as well as to improve the development process. The Real-Time Coloured Petri nets (RTCP-nets), which are a subclass of time coloured Petri nets, are used as a modelling tool. To make the nets more suitable for modelling and analysis RTCP-nets are derived from coloured Petri nets. Applications of RTCP-nets as a modelling and verification tool are strongly supported by the so-called Adder Tools. The formal description of RTCP-nets is not presented here since the paper focuses on the main properties of these and the supporting facilities of the Adder Tools. The approach is illustrated by a practical example, that shows the expressiveness of RTCP-nets for modelling and verification of real-time systems.

Vol. 30 No. 2

Z. Bubnicki:

On allocation problems for a complex of parallel operations described by uncertain variables


The paper is concerned with allocation problems for a class of parallel operations described by a relational knowledge representation. Unknown parameters in the relations are assumed to be values of uncertain variables described by certainty distributions given by an expert. Theorems concerning properties of the optimal allocation are presented. The equivalence of the solutions obtained by a direct approach to the allocation problem and by a decomposition is discussed. An example illustrates the presented method.

S. Dumitrescu:

Aspects context freeness for hyperedge replacement grammars


In this paper we are studying some aspects of context freeness concerning hyperedge replacement grammars. We introduce a Normal Form for hyperedge replacement grammars, which is related to Chomsky Normal Form for string grammars. For this, we define equivalence and we prove the existence of two grammars: a hyperedge replacement grammar without λ-productions and a grammar without rewritings. In the next step we prove the existence of a grammar where the productions have on the right side a hypergraph, with all hyperedges being labeled in the terminal alphabet. In all these considerations, context freeness is essential.

E. Fernandez, J. Navarro:

Computer-based decision models for R&D project selection in public organizations


Project selection is the most important problem concerning R&D management in public organizations, where weak heuristics are used for evaluating projects and making decisions about final portfolios. We propose here an integrated approach for analyzing projects and solving portfolio problems whose central parts are the use of decision tables as models of decision-maker’s preferences and beliefs, and a model of R&D portfolio quality derived from Utility Theory and based on fuzzy sets to model some sources of imprecision. The resulting optimization problem is very complex in order to be solved by classical mathematical programming methods, so we propose an evolutionary algorithm able to achieve a strong improvement of the quality of solution. Some results are applicable in other problems outside the scope of this paper.

Z. Pawlak:

Orthodox and non-orthodox sets - some philosophical remarks


We outline the relationship between classical (orthodox) sets from one side, and fuzzy and rough (non-orthodox) sets from another side. The classical concept of a set used in mathematics leads to antinomies, i.e., it is contradictory. This deficiency has, however, rather philosophical than practical meaning. Antinomies are associated with very “artificial” sets constructed in logic but not found in sets used in mathematics. That is why one can use mathematics safely. Fuzzy set and rough set theory are two different approaches to vagueness and are not remedy for classical set theory difficulties. Fuzzy set theory addresses gradualness of knowledge, expressed by the fuzzy membership, whereas rough set theory addresses granularity of knowledge, expressed by the indiscernibility relation. From practical point of view both theories are not competing but are rather complementary.

G.D. Samaras, N.F. Matsatsinis, C. Zopoudnis:

Towards an intelligent decision support system for portfolio management


The paper presents an Intelligent DSS to cover the needs in stock portfolio management. The system introduced develops the three tools of portfolio management: Fundamental Analysis, Technical Analysis and Market Psychology. In addition, it is also led by the investor’s profile in order to make a personalized investment decision. The system integrates multi-criteria analysis methods and AI technologies, in order to obtain an efficient system, better suited to the rapidly changing conjunctures of financial markets. It introduces to the potential investor a complete fully justified investment suggestion for portfolio management of the Athens Stock Exchange.

Y. Siskos, N. Bouranta, N. Tsotsolas:

Measuring service quality for students in higher education: the case of a business university


Student satisfaction barometers are of vital importance for the universities because they promote their internal re-organization, strengthen their image and emphasize on meeting the expectations and needs of students. Measuring student satisfaction by emphasizing on components of service quality delivered to students is an effective performance evaluation index. The paper presents an original study that measures the students’ satisfaction of a Greek Business University. The most important results are focused on the determination of the weak and the strong points of the university as well as on the identification of distinctive variations amongst the departments of the university.

Vol. 30 No. 3

J. Błażewicz, M. Borowski, P. Formanowicz, T. Głowacki:

On graph theoretical models for peptide sequence assembly


The amino acid sequences of proteins determine their structure and functionality, hence methods for reading such sequences are crucial for many areas of biological sciences. Obviously, the genetic information encoding proteins is written in DNA however, knowing gene sequences is not always sufficient for determining the corresponding amino acid sequences. Since direct methods for reading amino acid sequences allow for determination of only very short fragments, some methods for assembly of these fragments are required. In this paper, we show and analyze some graph theoretic models of the peptide sequence assembly process.

D. Emiris, D. Koulouriotis, N. Matsatsinis:

Development of an idef0 model od integrated logistics support system (ILS) for the armed forces


The cost of support for an expensive military system during its “in-service” phase of its life often exceeds the two-thirds of the entire life cycle cost. The support of a system in a military operational environment is the main subject of the Logistics Department and is realised through the collaboration of the maintenance and supply Departments. The success of this endeavour depends on the quantitative tasks need to be considered through the life cycle of the system and are related to its reliability, availability and maintainability. The management approach that is related to the control of this cost, the estimation and the determination of the type of supporting, is known in the international bibliography as Integrated Logistics Support (ILS). This approach materialises the doctrine “planning for support”, which ensures the integration of the processes of supply and support, in order to cover with success the needs of the system during its operational phase. This objective is achieved by the application of an analysis process known as Logistics Support Analysis (LSA). The result of this analysis is a dynamic database called Logistics Support Analysis Record (LSAR) and follows the system until the end of its life. The present study illustrates analytically the ILS processes according to the IDEF0 standard and is based on the simplification of the models that have been developed by the American and British Armed Forces.

G. Mavrommatis, J. Kalligatsis, J.-Ch. Panayiotopoulos:

MOP: Mutation-Oriented Programming


In this paper the notion of Mutation-Oriented Programming (MOP) is presented. MOP extends traditional Object-Oriented Programming model and is capable of maintaining its functionality not only in Regular but also in Irregular, Dynamic Data Spaces. A formulation, as well as approach techniques for the design and development of this new form of software, are given.

M. Sikora:

An algorithm for generalization of decision rules by joining


An algorithm for rules generalization consisting in joining of rules with the same structure is presented in the paper. The algorithm joins rules conditionals descriptors so as the language of rules representation is unchanged. A value of rules quality evaluation measure is a criterion deciding about advisability of rules joining. Some exemplary results of algorithm working is described in the paper as well. The tolerance rough sets model is used in rules induction.

S. Tsasakou:

Formal refinement modeling using patterns in hardware/software co-design


A co-design methodology is presented for correct stepwise refinement of abstract system architectures into lower-level implementation architectures. The methodology is based on the modeling of the basic refinement procedures (control and data related refinement) that constitute most of the system architecture implementations. The refinement models rely on the use of patterns, an idea/practice adopted from the software engineering world and adjusted to the needs of hardware-software co-design. Each pattern defines the steps that should be followed for the transition from an abstract system model to a more detailed one. The validity of each pattern is proved using the rules and axioms of TLA (Temporal Logic of Actions). The applicability of the presented methodology is exhibited through the use of the pattern-based refinement process in a representative design cases appearing in hardware-software co-design.

N.H. Viet, M. Kleiber:

Neural networks in solving systems of interval linear equations


In this paper, a new approach for approximating the algebraic solution of systems of interval linear equations, denoted here as SILE, is proposed. The original SILE problem is first considered in terms of an optimization problem. The exact arithmetic operations over interval numbers which appear in the cost function of this optimization problem are replaced by those performed with the use of some simple sigmoidal feed-forward neural networks. This modified cost function is then minimized using one of the gradient based algorithms. A number of numerical evaluations are provided in order to verify the proposed approach. The results are discussed and some final remarks are included.

Vol. 30 No. 4

G. Christodoulou, V. Zissmopoulos:

On-line maximum independent set in chordal graphs


In this paper we deal with the on-line maximum independent set and we propose a probabilistic O(log n)-competitive algorithm for chordal and interval graphs, proving that the same ratio is a lower bound of the problem. The relation of the on-line maximum independent set with the on-line admission control, allows us to obtain as particular case, an O(log n)-competitive algorithm for the on-line admission control in trees and lines. In addition to that, we propose a competitive algorithm for the on-line call admission of subtrees in trees.

M. Drozdowski, M. Lawenda:

The combinatorics in divisble load scheduling


Divisible load scheduling problem is studied in this work. Though tractability of this problem in the practical cases is considered as its great advantage, we show that it has a hard combinatorial core. Computational hardness and polynomial time solvability of some special cases are shown.

D. Koulocheris, V. Dertimanis:

A hybrid algorithm for the PEM estimation of ARMAX structures


This paper proposes a new methodology for the estimation of ARMAX models, based on the implementation of a hybrid optimisation algorithm and a corresponding estimation procedure. The specific algorithm attempts to interconnect the diverse characteristics of two entirely different optimisation techniques, deterministic and stochastic, combining high convergence rate with increased reliability in the search for global optimum, and it consists of a super-positioned stochastic global search, followed by an independent deterministic procedure, in which the analytical gradients of the ARMAX model are used. The corresponding estimation procedure is split into two parts, due to the mixed linear-nonlinear relationship between the prediction errors and the parameter vector, and assures the stability and invertibility of the resulted models. The parametric identification test case, which is considered in this study, refers to the estimation of an ARMAX model for the description of a half-car passive suspension system of a road vehicle.

A. Salappa, M. Doumpos, C. Zopoudnis:

Feature selection algorithms in classification problems: An experimental evaluation


Feature selection (FS) is a significant topic for the development of efficient pattern recognition systems. FS refers to the selection of the most appropriate subset of features that describes (adequately) a given classification task. The objective of this paper is to perform a thorough analysis of the performance and efficiency of feature selection algorithms (FSAs). The analysis covers a variety of important issues with respect to the functionality of FSAs, such as: (a) their ability to identify relevant features, (b) the performance of the classification models developed on a reduced set of features, (c) the reduction in the number of features, and (d) the interactions between different FSAs with the techniques used to develop a classification model. The analysis considers a variety of FSAs and classification methods.

M. Schechter, R.E. Steuer:

A correction to the connectedness of the Evans-Steuer algorithm of multple objective linear programming


The Evans-Steuer algorithm (and its ADBASE computerized implementation) for finding all eficient extreme points of a multiple objective linear program (MOLP) is based on eficient pivots. The justification of the algorithm rests on the assumption that the set of eficient basic index sets is connected with respect of eficient pivots. This assumption is incorrect. Nevertheless, the algorithm is valid and is, in fact, more eficient than originally believed.

R. Wrembel, B. Bębel, Z. Królikowski:

The framework for detecting and propagating changes from data sources structures into a data warehouse


In this paper we propose a framework for detecting changes in external data sources (EDSs) and propagating them into a multiversion data warehouse (MVDW). The architecture of our prototype MVDW uses an operational data store (ODS) as a buffering layer between EDSs and a MVDW. The functionality of the ODS that we developed is responsible for detecting structural changes in external data sources and creating the set of MVDW modification operations automatically. The operations can next be applied to a new or existing data warehouse version. Changes in data sources that are to be detected and the way they are to be propagated into a data warehouse are defined by a management software, also discussed in the paper.

Last changed on: 2008-05-19 by Bartłomiej Prędki