scholarly journals EFFICIENCY OF COMPUTER NETWORKS WITH SDN IN THE CONDITIONS OF INCOMPLETE INFORMATION ON RELIABILITY

2021 ◽  
Vol 5 (2) ◽  
pp. 103-107
Author(s):  
Ольга Зінченко ◽  
Віктор Вишнівський ◽  
Юлія Березовська ◽  
Петер Седлачек
Keyword(s):  
Incomplete Information ◽  
Computer Networks ◽  
Computer Network ◽  
A Priori ◽  
Packet Transmission ◽  
Reliability Indicators ◽  
Distribution Laws ◽  
Priori Information ◽  
Management Functions ◽  
Time Reserve

The paper analyzes the effectiveness of computer networks with SDN in conditions of incomplete reliability information. In order to ensure the specified indicators of the reliability of the computer network, it is recommended to use their guaranteed estimates. To increase the level of security of information systems and introduce the concept of time reserve in the process of packet transmission, it is necessary to separate the functions of traffic transmission from management functions. This is the basic principle of SDN. When using SDN technology in computer networks, it is possible to enter a time reserve when transmitting messages. This makes it possible to more accurately determine the reliability. The evaluation of the data transmission system of the computer network takes into account the possibility of entering a time reserve and obtained the basic calculated ratios for reliability indicators in terms of incomplete information about their distribution laws. A priori information is limited by knowledge of the first initial moments of mathematical expectation and variance. These results are a justification for the structure of computer networks that are designed or upgraded. You can also use this information to build highly reliable networks or technical facilities that exist in a single implementation.

TAKING INTO CONSIDERATION OF THE MULTIPLE MODE OF THE FUNCTIONING AND CHARACTERISTICS OF THE CONTROL IN RELIABILITY MODELS OF REPLACEMENT TIME SYSTEMS

2019 ◽  
Author(s):  
Iryna Kononova
Keyword(s):  
A Priori ◽  
Telecommunication System ◽  
Structural Element ◽  
Reliability Models ◽  
Quick Recovery ◽  
Reliability Indicators ◽  
A Priori Uncertainty ◽  
Control Of Parameters ◽  
Time Systems ◽  
Time Reserve

The article evaluates the reliability indicators of telecommunication system equipment, which can be represented by multi-mode objects of continuous and episodic use with a time reserve operating under conditions of a priori uncertainty. Particular attention is paid to consideration of the process of functioning of the system with a replenished time reserve. The telecommunication system includes an object represented by one structural element and used in different modes of operation. In each mode, the object can be used continuously or episodically (the object performs tasks that occur at random times), herewith only a certain part of its equipment is operating. The restoration of the facility's operation in each mode is based on the "quick" recovery scheme ("quick" recovery means that the repair time is much less than the average working time of the element between failures). Also, some cases of the transition of an object from one mode to another are considered, and the control system operates according to the method of sequential control of parameters. In this case, the system, after waiting mode, begins to analyze the first parameter of the monitored complex, then the second and so on. After analyzing the parameters, the system enters the waiting mode. These calculated ratios allow for a comprehensive assessment of the reliability of telecommunication equipment, taking into account the totality of the main factors that significantly affect the reliability of the equipment in real conditions of operation, make it possible to solve important practical problems which arise from the improvement of existing equipment and development of existing equipment.

Identification and Control of Multidimensional Delayed Processes in Conditions of Incomplete Information

2021 ◽  
Vol 27 (12) ◽  
pp. 658-667
Author(s):  
A. V. Medvedev ◽  
◽  
D. I. Yareshchenko ◽  
Keyword(s):  
Incomplete Information ◽  
A Priori ◽  
Identification Problem ◽  
Control Algorithms ◽  
Main Task ◽  
Multidimensional System ◽  
Implicit Equations ◽  
Priori Information ◽  
Definition Of ◽  
And Control

Problems of identification and control of multidimensional discrete-continuous processes with delay in conditions of incomplete information about the object are considered. In such conditions, the form of parametric equations for various channels of the object is absent due to the lack of a priori information. Moreover, multidimensional processes have stochastic dependences of the components of the vector of output variables. Under such conditions, the mathematical description of such processes leads to a system of implicit equations. Nonparametric identification and control algorithms for multidimensional systems are proposed. The main task of modeling such processes is to determine the predicted values of the output variables from the known input. Moreover, for implicit equations, it is only known that one or another output variable can depend on other input and output variables that determine the state of a multidimensional system. In this study, a nontrivial situation arises when solving a system of implicit equations under conditions when the dependences between the components of the output variables are unknown. The application of the parametric theory of identification in this case will not lead to success. One of the possible directions is the use of the theory of nonparametric systems. The main content of the work is the solution of the identification problem in the presence of dependencies of the output variables and then the solution of the control problem for such a process. Here you should pay attention to the fact that when determining the reference actions for a multidimensional system, it is first necessary to solve the system of reference actions, since it is not possible to choose arbitrarily setting influences from the range of definition of output variables. Computational eXperiments aimed at investigating the effectiveness of the proposed identification and control algorithms are presented.

scholarly journals Functional stability of information networks in the availability of limited a priori information about reliability

Connectivity ◽  
2020 ◽  
Vol 148 (6) ◽  
Author(s):  
S. M. Ishcheryakov ◽  
◽  
S. V. Prokopov ◽  
Yu. V. Karhapolov ◽  
Yu. V. Berezovsʹka
Keyword(s):  
Information System ◽  
Information Systems ◽  
Communication Systems ◽  
A Priori ◽  
Real Life ◽  
Design Stage ◽  
Functional Stability ◽  
A Priori Information ◽  
Priori Information ◽  
Time Reserve

In the article, based on the use of the results of evaluating of linear and fractional-linear functionals, sets of calculated ratios are obtained to determine the guaranteed (largest and smallest) values of basic of the reliability indicators of information systems in the presence of limited a priori information about the distributions of determining random variables which are represented by the initial moments. Such calculations at the design stage of complex information systems are predictable, because they serve as a grounding for the expected indicators of reliability of information systems that do not yet exist in real life. The peculiarity of the considered information systems is that they are used not continuously, but sporadically. In this case they perform tasks that come at random times. In such systems, the replenished time reserve provided in the system itself is used along with the random time reserve due to the nature of the task (this time reserve is determined from the moment of failure of the element or information system until the receipt of the task). Examples of sporadic information systems are VANET car networks, which have high latency requirements, real-time data centers, and communication systems. The main purpose of these calculations is as follows: a comparative analysis of various design (scheme) options for information systems at the design stage for a reasonable choice of the general structural scheme, methods of redundancy, methods of control and maintenance; a predicted assessment of the reliability of the system is given to substantiate the guaranteed conclusion that the designed information system can be manufactured according to the requirements that meet the requirements of functional stability; an approximate assessment of the reliability of information systems at the stage of testing a test sample for a reasonable determination of the terms of maintenance of systems in conditions of a priori uncertainty.

scholarly journals Ensuring functional stability of the information system with limited initial information about determining random values

2020 ◽  
Vol 69 (4) ◽  
Author(s):  
Yu. V. Berezovska ◽  
Keyword(s):  
Information System ◽  
Information Systems ◽  
A Priori ◽  
Random Variables ◽  
Distribution Functions ◽  
Functional Stability ◽  
A Priori Information ◽  
Experimental Development ◽  
Reliability Indicators ◽  
Priori Information

Ensuring functional stability, reliability and effective management in information systems is a complex and complex scientific task. At the stage of design and construction of information systems, reliability indicators are interpreted as characteristics of the created probabilistic mathematical models of objects, and at the stage of experimental development, testing and operation, the role of reliability indicators is performed by statistical assessments of the corresponding probabilistic characteristics. When assessing the reliability indicators of information systems, the necessary initial data for a priori probabilistic calculations are often lacking, and the statistical assessment is hampered by a small volume of tests, according to which it is possible to determine only the estimates of the moments of determining random variables of the process of functioning of information systems or its components (mathematical expectations and variances of mean time between failures, recovery time, standby time, etc.). However, in such a situation, it is necessary to substantiate some characteristics of the information system, for example, a reserve of time, guaranteed exact boundaries of the probability of system uptime and the availability factor. When obtaining specific estimates, the minimum a priori information is used, which corresponds to a large number of real situations when assessing the reliability of information systems with time redundancy in the process of design, testing and operation. This article highlights various types of functionals that characterize the efficiency of an information system, under conditions of incomplete a priori information about the distribution function of determining random variables, through which the main indicators of the reliability of information systems are expressed, an analytical method is proposed and substantiated for finding distribution functions that deliver the greatest or least linear value. or linear fractional functionals under moment constraints on variable distribution functions. The method is based on identifying the limiting distribution functions, constructing the corresponding limiting polynomials, and solving special inequalities.

Innovative Approach to Information Search by Example of a Patent Analysis of an Important Substitution Plan

2020 ◽  
pp. 143-157
Author(s):  
Maria A. Milkova
Keyword(s):  
Information Search ◽  
Topic Modeling ◽  
Cognitive Biases ◽  
A Priori ◽  
Import Substitution ◽  
Innovative Approach ◽  
Iterative Search ◽  
Comprehensive Picture ◽  
Priori Information ◽  
Selection Of

Nowadays the process of information accumulation is so rapid that the concept of the usual iterative search requires revision. Being in the world of oversaturated information in order to comprehensively cover and analyze the problem under study, it is necessary to make high demands on the search methods. An innovative approach to search should flexibly take into account the large amount of already accumulated knowledge and a priori requirements for results. The results, in turn, should immediately provide a roadmap of the direction being studied with the possibility of as much detail as possible. The approach to search based on topic modeling, the so-called topic search, allows you to take into account all these requirements and thereby streamline the nature of working with information, increase the efficiency of knowledge production, avoid cognitive biases in the perception of information, which is important both on micro and macro level. In order to demonstrate an example of applying topic search, the article considers the task of analyzing an import substitution program based on patent data. The program includes plans for 22 industries and contains more than 1,500 products and technologies for the proposed import substitution. The use of patent search based on topic modeling allows to search immediately by the blocks of a priori information – terms of industrial plans for import substitution and at the output get a selection of relevant documents for each of the industries. This approach allows not only to provide a comprehensive picture of the effectiveness of the program as a whole, but also to visually obtain more detailed information about which groups of products and technologies have been patented.

scholarly journals Computational Method for Wavefront Sensing Based on Transport-Of-Intensity Equation

Photonics ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 177
Author(s):  
Iliya Gritsenko ◽  
Michael Kovalev ◽  
George Krasin ◽  
Matvey Konoplyov ◽  
Nikita Stsepuro
Keyword(s):  
A Priori ◽  
Spherical Wave ◽  
Computational Method ◽  
Optical Systems ◽  
Radius Of Curvature ◽  
Imaging Method ◽  
Wavefront Sensing ◽  
Phase Imaging ◽  
Transport Of Intensity Equation ◽  
Priori Information

Recently the transport-of-intensity equation as a phase imaging method turned out as an effective microscopy method that does not require the use of high-resolution optical systems and a priori information about the object. In this paper we propose a mathematical model that adapts the transport-of-intensity equation for the purpose of wavefront sensing of the given light wave. The analysis of the influence of the longitudinal displacement z and the step between intensity distributions measurements on the error in determining the wavefront radius of curvature of a spherical wave is carried out. The proposed method is compared with the traditional Shack–Hartmann method and the method based on computer-generated Fourier holograms. Numerical simulation showed that the proposed method allows measurement of the wavefront radius of curvature with radius of 40 mm and with accuracy of ~200 μm.

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