Abstract: The subject of the research is the methods of network cyberspace analysis based on graph models. The analysis allows to find leaders of groups and communities, to find cohesive groups and visualize the results. The main methods of the graph theory used for cyberspace social networks are the methods of analyzing the centrality to determine the relative weight or importance of the vertices of the graph. There are known methods for analyzing centralities: by degree, by proximity, by mediation, by radiality, by eccentricity, by status, eigenvector, referential ranking. The disadvantage of these methods is that they are based only on one or several properties of the network participant. Based on the centrality analysis methods, a new generalized centrality method is proposed, taking into account such participant properties as the participant's popularity, the importance and speed of information dissemination in the cyberspace network. A mathematical model of a new method of generalized centrality has been developed. Comparison of the results of the presented method with the methods of the analysis of centralities is performed. As a visual example, a subgroup of cyberspace consisting of twenty participants, represented by a graph model, is analyzed. Comparative analysis showed the accuracy of the method of generalized centrality, taking into account at once a number of factors and properties of the network participant.

Keywords: degree centrality, weights of vertices, definition of group leaders, social networks, graph model, centrality method, community analysis methods, network cyberspace, closeness centrality, betweenness centrality

Abstract: The subject of the research is the implementation of the AES encryption algorithm based on AVR microcontrollers to provide secure data transmission in the sensor network. The sensor network is a network technique for the implementation of Ubiquitous computing environment. It is wireless network environment that consists of the many sensors of lightweight and low-power. Though sensor network provides various capabilities, it is unable to ensure the secure authentication between nodes. Eventually it causes the losing reliability of the entire network and many secure problems. Therefore, encryption algorithm for the implementation of reliable sensor network environments is required to the applicable sensor network. In this paper, the author proposes the solution of reliable sensor network to analyze the communication efficiency through measuring performance of AES encryption algorithm by plaintext size, and cost of operation per hop according to the network scale.

Keywords: encryption, low power consumption, data protection, data encoding, AVR Microcontroller, AES algorithm, wireless sensor networks, decryption, transmission speed, network latency

Abstract: Currently, the main method of monitoring of operating gas pipelines laid by the ground, has become in-line diagnostics, carried out by scanning their inner surface. The use of automated cyber-physical systems of non-destructive testing of gas pipelines will increase the level of man-made safety. The article discusses the types of wireless technologies, analyzes the effectiveness of using WFi technology to modernize the process of non-destructive testing of the pipeline in real time. A hypothesis is put forward on the operation of the pipeline as a waveguide for wireless data transmission. To solve this problem, the methods of data transfer theory, graph theory, analytical and simulation modeling are used. The scientific novelty consists in choosing and justifying the choice of using the method of transmitting data from non-destructive testing results over a wireless link in real time based on the analysis of transmitted data and existing technologies, as well as upgrading the design of the cyber-physical system for in-line diagnostics of the gas pipeline laid underground.

Keywords: robotic system, data transfer, nondestructive testing, pipeline inspection, wireless technology, WiFi, cyberphysical system, visual diagnoistic, WiMax, laser profilometry

Abstract: The researcdh object in this study involves the  multi-level satellite infocommunication networks. The dynamic influence of various factors upon the characteristics of communication lines in different elements of the network causes changes in the distribution of traffic within the studied network, which in turn can lead to a decline in service quality markers, one of which is the average delay in the delivery of information. The article presents the results of the development of the traffic optimization model in the satellite hierarchical communication network based upon the criterion of minimum mean delay time for the purpose of improving the quality of information flows in the studied network. The key method used to develop the optimization model is the node method  for the  tensor analysis of networks, which fits the requirements of accounting for the interaction of the network topology and the processes of servicing information flows, and the used set of initial data. The scientific novelty involves the use of the nodal tensor analysis method in order to optimize the traffic distribution in the hierarchical infocommunication satellite network using the criterion of minimum mean delay time by using an objective function that takes into account the average delay time in each system of the information transmission route and the constraints determined by the tensor equation of behavior of the initial network .

Keywords: satellite networks, average delay, tensor analysis of networks, node method, quality of service, hierarchical networks, network topology, inter-satellite link, system load, Lagrange multipliers method

Abstract: This article concerns the issue of improving performance when processing large amounts of information in data warehouses (storages). The main purpose is to increase the speed of the process of wiping out information in the cache of data warehouses, and, consequently to improve the processing speed of the cached data. The subject of research involves the algorithms of data extortion LRU1 and LRU2, as well as and structural organization of the control table. The article proposes the implementation of algorithms for wiping out information in the data warehouse cache on the basis of an associative data array. The results of a comparative analysis of the basic algorithms of information displacement used in the operational memory of computer systems (LRU, LFU, FIFO, Random) are presented in this article. The results of the development of algorithms for accelerated information extrusion in the cache of data warehouses are also presented. The author construes the systems of canonical equations for these algorithms are. The  mathematical model, which is used by the author,  is an executable formalized specification allowing for a direct transition from the DCS (the system of canonical equations) to the further hardware or software implementation of the proposed algorithms.

Keywords: systems of canonical equations, storages, caching, data wiping algorithms, LRU algorithm, MRU algorithm, ARC algorithm, data processing, automatic models, data storage

Abstract: The subject of the study is the telecommunications network presented in the form of a set of queuing systems. As a result of the study, the authors present a method of analysis of obtaining a mathematical model of optimal distribution of traffic of telecommunications network using the criterion of a minimum number of packets in services throughout the network. Optimization of traffic is performed in two stages. At the first stage, a general optimal solution is sought. At the second stage, the routes between each source-receiver pair within the optimal solution of the first optimization stage are determined. Two-step optimization reduces the number of independent variables in the objective function found at the first stage of optimization. To obtain a mathematical model of the network, tensor analysis of complex systems simultaneously allowing finding linearly independent (phase) variables is performed. This approach made it possible to minimize the dimension and complexity of the problem being solved. Scientific novelty in this article is an algorithm for obtaining a mathematical model of a telecommunications network allowing to find the optimal distribution of information flows through communication channels. The peculiarity of this method is that instead of independent variables in the objective function authors use not all possible traffic routes between each source-destination pair but phase variables of contour and node intensities, which in general will be less than routes. This reduces the dimension of the objective function, and, consequently, accelerates the search for the optimal solution.

Keywords: mathematical network model, queuing system, optimal traffic routes, orthogonal network, traffic engineering, traffic distribution, tenzor analysis, queueing network, telecommunication networks, graph telecommunications network

Abstract: The present article is devoted to the question about increasing productivity of the cache memory subsystem of data storage systems. The main purpose of the article is to increase the speed of executing the basic algorithms of the information search operation in controlling index structures. The subject of the research is the controlling index tables the execution of the basic algorithms is based on. In their article the authors offer to execute modified data processing algorithms and index based on a unique method of hashing. The authors provide results of the analytical modelling of initial and modified data processing algorithms using the method of Markov chains. The authors evaluate the average performance of these algorithms. They also carry out a computer-aided simulation modelling of the search operation within the data structures under research. Within the framework of the studied method of controlling the cache memory, the authors prove that it is reasonable to use hash tables in order to build controlling index tables that containt a great number of stored messages. The research shows that implementation of hash tables allows to significantly increase the speed of the basic data processing algorithms in the cache memory of data storage subsystems. 

Keywords: Markov chain method, simulation modeling, index tables, data structures, search operation, hash table, lists, cache memory, hashing, data storage systems

Abstract: The article is devoted to topical issues of coding in fiber-optic communication lines in the presence of the pattern effect, i.e. the effect of the dependence of the error rate in the process of information transfer on the kind of information. The object of the researh is the information coding methods. In his research Teymurov provides a general review of the coding methods used for fiber-optic communication lines with the pattern effect. Teymurov also analyzes disadvantages of the adaptive block coding method offered by A. S. Skidin and offers ways to eliminate them. The author examines the process of implementation of information coding methods based on the example of fiber-optic communcation lines. The author has also conducted the simulation of adaptive block coding and offered improvements for the multichannel high performance line with the signal modulation amplitude-difference method. The results have been analyzed and conclusions about applicability of the aforesaid codes. The author has developed new coding methods based on the adaptive block coding method offered by A. S. Skidin for communication lines with the pattern effect. The author has conducted a comparative analysis of these methods, the results of the analysis demonstrate that new methods eliminate more errors meanwhile the redundance and coding and decoding methods remain the same. The research aimed at the implementation of coding methods allow to use these methods not only for the aforesaid fiber-optic communication lines but also for any other lines with the pattern effect which proves the wide scope of the implementation of these methods. 

Keywords: nonlinear effect, pattern effect, intersymbol interaction, four-wave interaction, phasic cross-modulation, coding theory, adaptive block coding, constrained codes, information coding methods, fiber-optic communication lines

Abstract: The article addresses the issue of classification of modern cluster systems (clusters). The main objective of the study is to systematize the existing classifications of clusters and to determine a place for PCI Express standard based clusters in it. The goal is achieved by summarizing the existing classifications of clusters, allocation of important classification criteria among them and the introduction of new criteria for the classification of switching cluster systems. Besides, the authors give a detailed analysis of the situation in the classification of clusters of computer systems in general. To solve this problem the following methods were used: an analytical review of the known approaches to the classification of cluster systems and formal-logical method of classification. As the result of the research of known classifications of clusters and generalization of all of the above criteria, highlighting the especially significant and taking into account the new criteria, the authors suggest a general scheme reflecting both the position of all the clusters of computer systems in general and detailed classification within the  clustered systems.

Keywords: cluster systems, cluster classification, classification criteria, systematization of cluster systems, Flynn's taxonomy, R.Hokni classification, specialized communication, general purpose communication, PCI Express commutation, PCI Express standard

Abstract: The article discusses the implementation of a productive and reliable cluster with low cost. As a solution, the authors recommend building a cluster system based on the PCI Express data input / output protocol. The main goal is to find ways to increase the productivity of the cluster system and its circuit protection. The subjects of the study are the algorithms for data transfer and processing on the switch, algorithms for search and displacement data in storage system, switch ports arbitration scheme. The research methodology includes structured systems analysis in the domain of the connection structures, the construction of cache storage, methods of constructing cluster systems. The authors propose the following structural and algorithmic solutions: a modified algorithm for address translation of the external PCI Express Switch; an improved method and algorithm for data searching and processing in the cache data storage systems based on a unique hash; formalization of all stages of arbitration algorithms for ports and virtual switch channels.

Keywords: clusters, communications network, PCI Express protocol, data storage, a cache memory, switch, Port arbitration, address translation, hashing, FPGA

Abstract: The paper deals with technologies of distribution of exact time in the data communication networks. In particular the technologies based on the Network Time Protocol (NTP) are considered. It is important to point out that this article has especially practical character, it is reviewing an implementation of a proving ground of testing of appropriate technologies. By proving ground the authors mean a set of software and hardware solutions which can be used in case of implementation of technology, and which can be integrated by any principle in rather independent stends. The composition of the stends which are a part of a polygon is considered. Examples of the organization of subnets - clients of system of distribution of exact time are given. The optimal version of the logical organization of a subsystem of time synchronization is offered. Ways of further development of a proving ground are planned. A methodological basis of this research is an experiment. The proving ground allows to simulate a huge number of configurations of the subsystem of distribution of exact time and to measure the different parameters of this subsystem. Auxiliary methodology of this research is the methodology of simulation modeling allowing to create optimum configurations for the purpose of practical confirmation of their relative efficiency. The proposed technical solution of the educational proving ground has no domestic analogs: it is unique both as a set ot technical means for support of educational process and from the point of view of creation of complexes of support of scientific researches in the field of distribution of exact time. Authors also present original solutions in the proving ground, monitoring of the environment and separate components of the equipment.

Keywords: IT infrastructure, standards of time, clock synchronization, distribution of exact time, multiservice networks, GPS, NTP, PTP, Sync Ethernet, Petri net

Abstract: The purpose of the study is in increasing the protection of nodes when accessing resources of an outside network. The objects of the study are the schemes of secure access from corporate network nodes to the information in the external network via "Direct connection" and "Connecting node". The study of these schemes is carried in terms of improving the security of the terminal node of corporate network, convenience and quality of organizing access of this node to the external network resources, as well as the complexity of the implementation of these schemes. In addition, the paper considers the possibility of protecting corporate network nodes from DDoS-attacks. The basis of the research is in the method of comparative analysis, which allows to reveal the advantages and disadvantages of each of the schemes. Based on the results it can be concluded that the scheme of "Direct connection" should be used in the following cases. Firstly, when it is impossible to make significant changes to the existing network architecture. Secondly, when the organization has limited financial resources. And thirdly, if it is necessary to work with external network resources in real time. Scheme "Connecting node", in contrast, requires (radical) rebuilding of network architecture and significant financial costs, but allows a much greater extent than the scheme of "direct connection", protecting an organization from the threats from the external network.

Keywords: encryption, network organization, firewalls, unauthorized access, information security, information technology, information protection, protected storage, monitoring of network traffic, access control

Abstract: In the given article the authors examine the problem of applicability of determining the power coefficients for modern processors and graphic cards. The article presents the analysis of the existing methods of hardware testing and shows the solution that allows evaluating PC components with less time and more meaningful results.  The approach suggested makes it possible to avoid marketing ploys used by the hardware companies for increasing profit. The use of the data received from the described module allows to gather real and full information about the power of your processor and video card. The subject of the study is not just in calculating the coefficient of each component of PC, but also in grading, that helps to relate the components against each other which  and to judge the optimality of the assembly as a whole. During the developing of presented modules and studying of the existing software for this problem the authors concluded the impossibility of a full assessment of the power of modern graphics cards and CPU. The methods of a full load of PC components and their ranging were tried out for selecting the most accurate and less time consuming. Calculation of coefficients has been performed on more than ten assemblies of different capacities and has proved to be reliable and applicable to each specific set of processor and graphics card. Based on the research shown  in the article it can be concluded that none of the existing testing system is capable of presenting the correct rating and the accurate enough information in a minimum period of time. The presented system developed during the study can be used in computer analysts and for private use and to test power.

Keywords: components, coefficients, configuration, power, evaluation, modules, optimality, testing, processor, video card

Abstract: The subject of the study is to describe the topology of the network by using graph theory. The purpose of the study is to construct the graphic descriptions of a computer network, a mathematical model and notation (language) for storing and processing computer network. All these problems are related and in the study the author focuses on describing the basic topologies "bus", "star", "ring" using graphs for further development and construction of a mathematical model, language notation of mixed network topology using various components. Creating a mathematical model and graphical / symbolic notation of the language is an important step in the task of building a theoretical mathematical apparatus for the creation of computer-aided design and automated control systems for telecommunications networks. The study uses analysis of the existing topology networks, the theory of networks and telecommunication devices, mathematical apparatus of graph theory and the theory of hypergraphs. The problem of constructing computer-aided design of computer networks is relevant since the beginning of the development of computer networks and up to the present time. Invention of new telecommunication technologies and new areas of their application leaves this task up-to-date and requires the development of new approaches. The novelty of the research is in developing methods to describe the classical topology in the context of the task of building a network topology with a complex combination topology. The author describe the classical topologies using graphs, proposes methods for replacements and decomposition. The results can be used in the development of the graph and the symbol models of telecommunication network topology with a complex mixed topology for use in computer-aided design and automated control systems of telecommunication networks. 

Keywords: binary tree, graph, bus network topology, ring network topology, star network topology, network topology, topology, hypergraph, graph theory, CAD

Abstract: In this paper we propose a new systematic approach to monitor forest fires over large areas. Established architecture of the complex, as well as effective methods of centralization and decision-making. Scientific and technical challenge is to create a system of distributed video surveillance to solve the problem of early detection of forest fires. This article discusses the existing fire detection approaches: the use of specialized towers, fire detection methods from the air, with the use of aircraft of various classes, a holistic approach to forest fire monitoring system uses satellite monitoring, video monitoring system. The described system is designed for the detection of forest fires and the determination of their spatial coordinates in real time. For the operation of the software complex towers and existing infocommunication data transmission medium can be used. This article analyzes existing approaches in the field of forest fire monitoring. A new systematic approach to problems of this kind, which is characterized by high performance and maximum efficiency of the concept solutions with minimal resource costs.

Keywords: GPS, GLONASS, real time, distributed system, forest fires, monitoring system, design, integration, access, systems approach