№ 818 (2015)
УДК 681.3.06+519.6(075.8)
Л. І. Танцюра
Державний університет телекомунікацій, Київ
АНАЛІЗ НАДІЙНОСТІ КОМП’ЮТЕРНОЇ МЕРЕЖІ НА ОСНОВІ БІНАРНОЇ ДІАГРАМИ РІШЕНЬ
© Танцюра Л. І., 2015
Досліджено спосіб оцінки надійності комп’ютерних мереж на основі бінарної діаграми рішень (БДР). Розглянуто різні алгоритми обчислення надійності комп’ютерної мережі на основі БДР: алгоритм факторизації, алгоритм, що ґрунтується на пошуку мінімальних шляхів або перерізів, алгоритм створення БДР без отримання булевого виразу. Методи обчислення надійності на основі БДР дають змогу обчислити надійність мережі із сотень елементів.
Ключові слова: надійність мережі, мінімальний шлях, мінімальний переріз, декомпозиція Шеннона, бінарна діаграма рішень (БДР), алгоритм Дейкстри,
2-термінальна надійність.
L. I. Tantsiura
State university of Telecommunication, Kyiv
COMPUTER NETWORK RELIABILITY ANALYSIS BASED ON BINARY DECISION DIAGRAM
© Tantsiura L. I., 2015
The present paper is aimed at investigating modelling and analysis techniques for the calculating the reliability of computer communication network using binary decision diagram. The network can be represented in a form of a graph, whose elements (vertices and edges) are considered as binary objects characterized by a working or a failed condition. Nodes and communication links of computer network may fail with known probability. The network reliability is defined as the probability that all nodes, or a subset of the nodes, of the graph communicate through at least one path of working edges. Failure of a single component may directly affect the functioning of a network. Determination of the probability properties of the network is based on Binary Decision Diagram and Shannon’s decomposition principle. Binary decision diagram is a modern data structure proved to be compact in representation and efficient in manipulation of Boolean formulas. A path is defined as asset of edges so that if these edges are all up, the system is up. A path is minimal if it has no proper subpaths. A cut is defined as a set of edges so that if these edges are all down, the system is down. A cut is minimal if it has no proper subcuts. Different approaches are based on the use of BDD. One is factoring algorithm. The idea is to choose an edge and break the model down into two cases: the first assumes the edge has failed, the second assumes it has not failed. For each case, a new reliability graph is built by taking into account the behavior of the chosen edge. The alternative class of methods is to directly obtain minpaths or mincuts. Minpaths are searched by means of the Dijkstra algorithm, while mincuts are searched by means of a recursive algorithm. In these methods we first enumerate all the minpaths and mincuts of the given network and then the reliability expression is evaluated using different methods, like inclusion-exclusion method or sums of disjoint products. There are some disadvantages in the above methods. In the factoring algorithm, the number of factored reliability graphs will increase exponentially with the number of edges increases. In the minpaths or mincuts methods, as the number of edges becomes large, the number of minpaths or mincuts will be large and inclusion-exclusion or sums of disjoint products expression will be increased too large. Size of BDD strongly depends on the ordering of variables. The size of BDD means the total number of non-terminal vertices in the BDD and the number of vertices in particular level. There is no polynomial search algorithms for optimal variable ordering.
The present paper introduces BDD representation of the 2-terminal connectivity of a graph without preliminary search for the minpaths or mincuts. The algorithm starts from the source node and visits the graph until the destination node is reached. The BDD construction starts recursively once the destination node is reached. The BDD’s of the nodes along a path from source node to destination node are combined in AND. If a node possesses more than one outgoing edge the BDD of the paths starting from each edge are combined in OR. A bridge network with directed arcs is considered as an example under assumption that only arcs can failure.
Key words: network reliability, minpath, mincut, Shannon’s decomposition, Binary Decision Diagram (BDD), Dijkstra algorithm, 2-terminal reliability.
Літератури – 15
УДК 621.396.96
С. Є. Фабіровський, І. Н. Прудиус
Національний університет “Львівська політехніка”
ПІДВИЩЕННЯ РОЗДІЛЬНОЇ ЗДАТНОСТІ БАГАТОСПЕКТРАЛЬНИХ ЗОБРАЖЕНЬ МЕТОДОМ СУБПІКСЕЛЬНОЇ ОБРОБКИ
© Фабіровський С. Є., Прудиус І. Н., 2015
Розглянуто методи синтезування багатоспектрального зображення низької роздільної здатності й панхроматичного зображення високої роздільної здатності у високороздільне кольорове зображення, їх переваги та недоліки. Для забезпечення високої роздільної здатності останнього запропоновано метод, оснований на використанні субпіксельної обробки, суть якої полягає в обробці вихідних даних сенсорів у вигляді ПЗЗ лінійок, зсунутих на половину піксела одна відносно іншої. Представлено результати моделювання запропонованого методу та одержано синтезовані кольорові зображення з підвищеною роздільною здатністю.
Ключові слова: комплексування, обробка зображень, субпіксельна обробка зображень, просторова роздільна здатність, багатоспектральні зображення, панхроматичне злиття, оптичний давач, інтерполяція, відновлення, дистанційне зондування Землі.
S. E. Fabirovskyy, I. N. Prudyus
Lviv Polytechnic National University
IMPROVING THE RESOLUTION OF MULTISPECTRAL IMAGES BY SUBPIXEL PROCESSING METHOD
© Fabirovskyy S. E., Prudyus I. N., 2015
The methods, their advantages and disadvantages, of fusion a low-resolution multispectral and panchromatic high-resolution image in high-resolution color image are considered. Is proposed a method to provide high-resolution, which is based on the use of sub-pixel processing, the essence of which is the handling of input data in the form of a CCD sensor arrays shifted by a half pixel with respect to each other. Using of subpixel imaging technology can improve the device resolution, or in the preservation of the low resolution, to reduce the system focal length and reduce the weight and volume of the optical system, which is very important for monitoring systems.
The flow charts of algorithms to improve the multispectral images resolution using of subpixel image processing are synthesized. The simulation results of the proposed method and the obtained synthesized color images with high resolution are presented. The complexity and speed of the proposed method are calculated.
As a result it was succeeded effectively to improve the resolution and formation quality of multispectral image.
Key words: data fusion, image processing, subpixel image processing, spatial resolution, multispectral images, pan-sharpening, optical sensor, interpolation, restoration, remote sensing of the Earth.
Літератури – 11
УДК 621.372.061
Ю. І. Шаповалов, Б. А. Мандзій, Д. Р. Бачик
Національний університет “Львівська політехніка”
ДОСЛІДЖЕННЯ СТІЙКОСТІ ПАРАМЕТРИЧНИХ ПІДСИЛЮВАЧІВ У СЕРЕДОВИЩІ MAOPCs
© Шаповалов Ю. І., Мандзій Б. А., Бачик Д. Р., 2015
У пропонованій роботі наведено результати дослідження асимптотичної стійкості одно- та двоконтурного параметричних підсилювачів. Оцінка стійкості у системі функцій MAOPCs основана на визначенні коренів знаменника параметричної нормальної передавальної функції кола, що має вигляд степеневого полінома від комплексної змінної.
Ключові слова: лінійне параметричне коло, частотний символьний метод.
Yu. I. Shapovalov, B. А. Mandziy,D. R. Bachyk
Lviv Polytechnic National University
INVESTIGATION OF STABILITY OF PARAMETRIC AMPLIFIERS IN AN ENVIRONMENT MAOPCs
© Shapovalov Yu. I., Mandziy B. А., Bachyk D. R., 2015
The paper considers the question of the research of assessment of the stability of linear periodically time-variable circuits by the frequency symbolic method. The function system MAOPCs, which is based on the frequency symbolic method, is an effective tool of investigation of linear periodically time-variable circuits and in particular parametric amplifiers. The assessment of circuit stability in the system MAOPCs is carried out by the real parts of the denominator roots of a normal parametric transfer function of the inertial part of circuit, which is also defined by the frequency symbolic method in the form of approximation by the Fourier trigonometric polynomials. If the real parts of roots are negative, the circuit is asymptotically stable and is not stable if the real part of at least one of the roots is equal to zero or positive. This criterion of asymptotic stability deservedly gained great importance with the appearance of such an effective method of formation of parametric transfer functions as frequency symbolic method. This paper presents the results of research of asymptotic stability of one- and double-circuit parametric amplifiers. For a single-circuit parametric amplifier with two parametric elements maps of stability for different phase differences of parametric elements were built. When the phase difference is 0 ° zone of stability is the biggest and when the phase difference 180 ° zone of stability is the smallest. These two cases are called in literature a synchronous and asynchronous modes and it is shown that energies brought into the circuit by change of capacitance and inductance in the first case are deducted, and in the second case are attached. This fact has received full confirmation in experiments carried out in the system MAOPCs. In this paper it is shown that the formation of parametric transfer function by the frequency symbolic method and determining the roots of the denominator in which parameters of the circuit set in symbolic form nowadays is the most effective tool of assessment of the asymptotic stability of electronic devices which are represented by linear periodically time-variable circuits. This approach allows you to build the trajectories of roots and maps of stability under multiple change of numerical values of symbolic parameters of circuit. The results of computer experiments presented in this paper made it possible to draw the following conclusions:
– complete coincidence of the results between programs MAOPCs and Micro-Cap proves the adequacy of transfer functions formed by frequency symbolic method and high accuracy of assessment of stability through the roots of the polynomial;
– the frequency symbolic method allows you to effectively assess stability and to form trajectories of roots or map of stability of circuit by the change of its random parameters that it is sufficiently comfortable at stability control in tasks of statistical character and optimization of parametric devices;
– computer experiments have shown that the formation of parametric transfer function by the frequency symbolic method and determining the roots of its denominator nowadays is the most effective tool of assessment of the asymptotic stability of electronic devices which are represented by linear periodically time-variable circuits.
Key words: linear periodically time-variable circuits, frequency symbolic method, stability.
Літератури – 7
УДК 621.397+681.723
В. І. Шклярський, Ю. М. Матієшин
Національний університет “Львівська політехніка”
ВІДОБРАЖЕННЯ РЕЗУЛЬТАТІВ ВИМІРЮВАННЯ ПАРАМЕТРІВ ДИНАМІЧНИХ МІКРООБ’ЄКТІВ ТЕЛЕВІЗІЙНИМ СКАНУВАЛЬНИМ ОПТИЧНИМ МІКРОСКОПОМ
© Шклярський В. І., Матієшин Ю. М., 2015
Розглянуто питання відображення результатів вимірювання параметрів динамічних мікрооб’єктів за допомогою телевізійного сканувального оптичного мікроскопа. При цьому мікрооб’єкти можуть бути як одиничними, так і перебувати у групі з декількох окремих динамічних мікрооб’єктів. Наведено принципи та алгоритм роботи мікроскопа, що забезпечують відображення результатів вимірювання параметрів як окремих динамічних мікрооб’єктів, так і усієї групи.
Ключові слова: телевізійна сканувальна оптична мікроскопія, відображення результатів вимірювання параметрів динамічного мікрооб’єкта, група динамічних мікрооб’єктів.
V. I. Shkliarskyi, Y. M. Matiieshyn
Lviv Polytechnic National University
DYNAMIC MICROOBJECTS PARAMETERS MEASUREMENT RESULTS DISPLAY WITH THE TELEVISION SCANNING OPTICAL MICROSCOPE
© Shkliarskyi V. I., Matiieshyn Y. M., 2015
Television scanning optical microscope (TSOM) combined with computer support allows control of its modes in general, individual nodes, image processing and transmission capabilities, storage and playback of the data in the right form for the operator (graphs, tables, diagrams, etc.).
An example of the effective use of computer technology symbiosis and measuring systems are complex CASA (Computer-aided sperm analysis). Graphic display of measurement results methods are widely used in cytophotometry to analyze the distribution of absorbing substances in the cells processes. These ways of quantitative assessment of cytological microobjects structure (MO) are based on microphotometry: histogram and topograms, calculating of the surface relief indicator and texture coefficient and so on. It is possible to represent MO in digital or gray-scale fields, as well as pseudorelief.
Solving problems related to the display of the velocity vector in the form that is most visible to the operator and can give him the maximum amount of information about the behavior of MO, as well as to simplify and speed up its work, is very important. This article contains analysis ways of display the results of measurement parameters in TSOM as single dynamic MO and dynamic individual MO which are in a group of several MO moving chaotically – with variable velocity and direction of motion. The basic principles of TSOM in determining the dynamic parameters of individual MO and averaged parameters of several MO as a whole.
A vector representation of measured values used in vector-cardiography, which originated in the development of electrocardiography. Presenting measure as vektorogram enables display bias in the direction of MO. The pronounced tendency of MO movement within a certain angular sector at a certain velocity rate may indicate different defects of physiological character in the structure of the MO. Examples are the different forms of violation of human sperm structure, which affect the nature of their movement velocity and the consequent loss of the ability to fertilize.
MO real movement usually occurs in 3-D space. In this case, three-dimensional model is built as vektorogram. It gives researchers the complete information on the movement of MO, providing at the same time to assess the actual relationships between different components of the movement.
Under the group of dynamic MO will realize several separate dynamic MO, which are within sight of TSOM have chaotic (random) motion with variable velocity and direction of movement. Often in modern medicine, microbiology, ecology and many others there is a need to analyze the dynamic parameters not only individual MO, but averaged dynamic parameters of the group as a whole. To do this successfully, you can use all the above listed ways reflect the results of measuring the dynamics of MO.
Key words: television scanning optical microscopy, dynamic microobject parameters measurement results display, group of dynamic microobjects.
Літератури – 9
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