Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Journal of Achievements in Materials and Manufacturing Engineering

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: chaotic algorithms

Sortuj według:

Ogranicz wyniki do:

Efficiency of the computer tomography algorithms in examination of the internal structure of materials with non-transparent elements by using the incomplete information

Grzymkowski R., Hetmaniok E., Pleszczyński M.

Journal of Achievements in Materials and Manufacturing Engineering

2011

Vol. 49, nr 2

285--298

Purpose: of this paper: The effectiveness of computer tomography algorithms applied for reconstructing the internal structure of objects containing the non-transparent elements is discussed, in conditions of the incomplete information about the examined object. Design/methodology/approach: Problem of the internal structure examination of an object with non-transparent elements, without its destruction, is considered by means of the classical and non-classical algebraic algorithms of computer tomography used in standard approaches and in cases of incomplete projection data. Findings: Computer tomography algorithms, known from literature and designed by the authors, are tested in solving the problems of reconstructing the discrete objects of high contrast with non-transparent elements, with regard to their precision, convergence and utility. Carried out research indicate that the chaotic algorithms are more efficient, for the same values of parameters, in comparison with the corresponding classical algorithms. Practical implications: Problems considered in the paper can arise in some technical issues, for example, in exploring the coal interlayers in looking for the compressed gas reservoirs which can be dangerous for the people’s life and health, in which application of the standard algorithms of computer tomography is impossible for some reasons (like size of the examined object, its localization or its accessibility). Originality/value: In the paper the originally designed by the authors reconstruction algorithms are presented which appear to be more effective than the standard algebraic algorithms adapted for solving problems with the incomplete projection data.

Application of the computer tomography in examination of the internal structure of materials by considering the specific conditions of the problem

Grzymkowski R., Hetmaniok E., Pleszczyński M., Zielonka A.

Journal of Achievements in Materials and Manufacturing Engineering

2010

Vol. 43, nr 1

288--298

Purpose of this paper: In this paper we present a summary of the results reached in the field of computer tomography applied in some special case – for the problem of incomplete projection data. This particular problem arises in the technical issues in which, for some reasons (like for example size of the examined object, its localization or its accessibility), it is impossible to apply the standard algorithms of computer tomography. Design/methodology/approach: In the paper we discuss the standard algebraic algorithms of computer tomography and, additionally, the new algebraic algorithms (parallel and chaotic), designed by the authors, suitable not only for the case of incomplete projection data but also useful in the standard approach. Findings: The above mentioned algorithms are tested in solving the problems of reconstruction the discrete objects of high-contrast. Moreover, convergence, stability and utility of the algorithms are proved experimentally. Research limitations/implications: Algorithms, created by the authors, are designed for the multiprocessor computers which allow to execute the calculations simultaneously. However, the results compiled in the paper were elaborated by using the one-processor computer. Calculations in which the parallel computing structure will be used are planned for the nearest future.Practical implications: Possibilities of the effective applications of the discussed algorithms in different practical technical problems are showed in the paper. Research, done till now, indicate the chances of applying the proposed algorithms in certain technical problem in which the incomplete projection data appear (like, for example, in searching for the elements in material which cause decreasing of its strength or in looking for the compressed gas reservoirs in the coal bed, which can be dangerous for the people’s life and health). Originality/value: The paper presents the reconstruction algorithms (block and chaotic-bloc), designed by the authors, which appear to be more effective than the standard algebraic algorithms adapted for solving problems with the incomplete projection data.