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This paper is primarily concerned with a numerical model of MHD waves. While a hyperbolic system of wave equations admits a shock solution the MHD equations are not strictly hyperbolic. As a consequence of that these equations require special numerical treatment. An application of a resulting numerical code to a problem of wave propagation in a coronal loop is presented.
In the paper the computational method and results of simulation of potential distribution inside the plasma region of the negative ion source are presented. The code uses the well known PIC method [1] for the local charge density determination and finite differences method for the Poisson equation [2]. For simplification, the plasma model does not take into account the interaction between the plasma...
In this work we present and discuss some methodological issues associated with the generation of the computer based anatomical models. The importance of the virtual patient models is becoming increasingly recognized in modern medicine. The advantages of using such biomedical virtual models are analogous to those of real system behavior simulation in the engineering or material sciences. Particularly...
In the article a new approach for solving Markovian linear systems is presented. It is the inverse iteration with the use of the WZ factorization. The paper contains the theoretical base of the method and numerical experiment results where the accuracy and the performance time were investigated. A modified (with the use of the SBLAS library and the Harwell-Boeing sparse matrix storage scheme) method...
In this paper a method of automatic generation of test scenarios for verification of specification requirements (temporal and functional) for reactive embedded systems is presented.
The following article presents the theoretical way of implementing the expert system which, due to the co-operation of the system with the person conducting the endoscope examination, will enable the medical staff to qualify and classify the observed pathological changes in a quicker manner.
The presented article constitutes a fragment of research which aims at automatic recognition of disfluencies in the speech of stuttering people. In the utterances of such people difficulties frequently appear in words beginning with stop consonants. On the basis of acoustical analyses of the episodes, procedures for their automatic detection have been elaborated. The procedures apply fuzzy logic.
The paper presents information theory based image segmentation algorithms. Both advantages and problems related to them are discussed. Then a segmentation framework based on combination of information theory and fuzzy logic is proposed.
This paper describes generalization of multi-class region growing algorithm allowing for segmentation of 3D images (series of slices). The multi-class region growing algorithm was proposed in [1]. Additionally, a new method for finding the start region was presented. As its 2D version the new algorithm does not need initial parameters since it features segmentation quality assessment. A series of...
The analysis of medical images for the purpose of computer-aided diagnosis and therapy planning includes segmentation as a preliminary stage for the visualization or quantification. In this paper, we present the first step in our fuzzy segmentation system that is capable of segmenting magnetic resonance (MR) images of a human brain. The histogram analysis based on the S-function membership and the...
A Decision Support System for Medical Applications was designed by applying the rough set theory to generate rules from the collected data. The data are kept in a table representing information system. There are some improper data in information systems and their removal can improve the quality of the retrieved information. By improper data we can understand such objects that disturb rules generation...
In recent years spectral methods, especially wavelets theory, have gained wide popularity in digital image processing because they allow for very sparse and efficient image coding. Although they are good in analyzing one dimensional signal, they cannot properly catch line discontinuities, so they are often present in two dimensional signals, that is in images. To avoid these problems the theory of...
This paper describes OpenMP parser for Ada, which is meant to make parallel programming in Ada simpler. We present different approaches to parallel programming and advantages of OpenMP solution. Next, implemented directives and clauses are described, and appropriated examples given. General look at parsing algorithm is presented in another part of this article. Finally, we present the source code...
The number of binary functions that can be defined on a set of L vectors in R^N equals 2^L . For L>N the total number of threshold functions in N-dimensional space grows polynomially (2^N(N-1))while the total number of Boolean functions, definable on N binary inputs, growsexponentially ( 2^2^2), and as N increases a percentage of threshold functions in relation to the total number of Boolean functions...
Model checking of software systems becomes more effective each day. However it still can not handle huge state spaces of real software. Particularly, concurrent systems are hard to verify. Abstraction techniques are one of the solutions aimed at managing the complexity problem. This paper describes the object oriented abstraction algorithm. It allows semi-automatic abstraction of real (i.e. Java)...
Special interest in designing, constructing and exploitation of fault tolerant systems is connected with the need of attending to critical infrastructure systems. In this paper we focus on presentation and analysis of the requirements demanded on the context of fault tolerance assurance in the critical infrastructure systems. Especially, we take into consideration algorithmical and topological methods...
Three simulation algorithms of Turing machines by means of real recursive functions are proposed. Moore's shifting mapping GS is used to this end. The relationship between a simulation dimension and classes of rj -hierarchy is established.
In this paper there are presented algorithms for multilevel hierarchical threshold secret sharing schemes based on the interpolation of Hermite type, which use either traditional Shamir's keys or polynomial and orthogonal polynomial keys. These algorithms enable to compute the probability of authenticity of shares during the process of recovering the keys. In addition, two models of secret sharing...
The article is devoted to the problem of finding the triples of integer numbers generating equal sums of the squares in the linear combination. At first the theorem giving the conditions of existing two equal sums of the squares is presented. Based on it the algorithm for finding the triples of the integer numbers generating equal sums of the squares is built. The time complexity is calculated and...
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