Informatica

The integration of Lithuania to the European Union increases openness of its economy and gives an impulse to create financial and legal system aligning with the leading European countries. The universal German banking market conditioned more universality in Lithuanian banking system. Initially securities and insurance business was partly restricted for banks in Lithuania, but restrictions are gradually diminishing.

The paper develops the idea of valuation capital market regulations efficiency. The performance and efficiency measurement idea is very widely spread in the private sector. However efficiency concept in a public sector is rather new approach and still underdeveloped. The goal of this paper is to reveal the possibilities to measure the efficiency of a public sector performance by applying some descriptive dependencies systems and by using the capital market regulations as an example to disclose the possible outcomes of that analysis process.

This paper discusses the normality assumption of the market model errors, conventionally accepted. Some other possible specifications are proposed and their performance is testing using a test statistic based on the empirical distribution function of the residuals of the model and assuming that the null distribution can depend on some unknown parameters. The parametric bootstrap method is used. Empirical evidence is provided using a sample of thirty companies of the Spanish Stock Market.

One of speech synthesis main problems is synthesis of unvoiced fricatives. One of our previously stated conclusions is that consonant x is influenced by before and behind existing phonetic elements. The aim of experiments described in this paper is to evaluate influence of different x allophones for speech intelligibility and automatic speech recognition.

Peyravian and Zunic (2000) proposed a password transmission scheme and a password change scheme over an insecure network. Their proposed solutions do not require the use of any symmetric-key or public-key cryptosystems. However, this article points out that their schemes have several security flaws for practical applications. A slight improvement on their schemes is proposed in this paper to remove the security flaws.

This paper describes a preliminary algorithm performing epilepsy prediction by means of visual perception tests and digital electroencephalograph data analysis. Special machine learning algorithm and signal processing method are used. The algorithm is tested on real data of epileptic and healthy persons that are treated in Kaunas Medical University Clinics, Lithuania. The detailed examination of results shows that computerized visual perception testing and automated data analysis could be used for brain damages diagnosing.

The aim of the given paper is development of a joint input-output approach and its comparison with a direct one in the case of an additive correlated noise acting on the output of the system (Fig. 1), when the prediction error method is applied to solve the closed-loop identification problem by processing observations. In the case of the known regulator, the two-stage method, which belongs to the ordinary joint input-output approach, reduces to the one-stage method. In such a case, the open-loop system could be easily determined after some extended rational transfer function (25) is identified, including the transfer functions of the regulator and of the open-loop system, respectively, as additional terms. In the case of the unknown regulator, the estimate of the extended transfer function (27) is used to generate an auxiliary input. The form of an additive noise filter (36), that guarantees the minimal value of the mean square criterion (35), is determined. The results of numerical simulation and identification of the closed-loop system (Fig. 5) by computer, using the two-stage method and the direct approach are given (Figures 6–12, Table 1).

The sequential nonlinear mapping is suitable for sequential detection of states of dynamic systems (Montvilas, 1999a). In addition, it can indicate the undesirable states and even the damages of dynamic systems. The last is complicated when the damage is caused by a small changing of respective parameter describing the state. In the paper the problem of nonlinear mapping to be sensitive for the small changing of parameters and the problem related with dimensionality of parameters are solved by using a special pre-processing of data. Examples are given.

The article presents results of the national survey on teaching and studying informatics at Grades 11 and 12 in the Lithuanian secondary school. This study explores the influence of different factors on students' achievements in informatics. The purpose of this work is to study the interaction between various characteristics of student, teacher and school, and factors of studying and teaching informatics and their joint influence on students' achievements in informatics. In addition, the article explores and contrasts the casual influence structures on the students' knowledge of two different branches of informatics: computer application and programming. To explore these interrelations, PLSpath analytic procedure has been used.

Filtering of feature matches is heuristic method aimed to reduce the number of feasible matches and is widely employed in different image registration algorithms based on local features. In this paper we propose to interpret the filtering process as an optimal classification of the matches into the correct or incorrect match classes. The statistics, according to which the filtering is performed, uses differences of the geometrical invariants obtained from ordered sets of local features (composite features) of proper cardinality. Further, we examine some computationally efficient implementation schemes of the classification. Under the assumption of Gaussian measurement error, the conditional distribution densities of invariants can be approximated by well-known linearization approach. Experimental evidences obtained from fingerprint identification, which confirm viability of the proposed approach, are presented.