Радиотехника

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Зараз показано 1 - 20 з 2054

Algorithm for multi-board radio-electronic devices synthesis on maximal accepted overheat
(ХНУРЭ, 2017) Sinotin, A. M.; Tsymbal, O. M.; Kolesnikova, T. F.; Sotnik, S. V.
The provision of a normal thermal regime for the future design of the radio-electronic device at the design stage prior to its manufacture is considered. The effect of the form of the radio electronic device on its temperature regime at the stage of its design is established. Tha algorithm for the thermophysical design of single-unit radioelectronic devices has been developed. For the first time recommendations were received on the choice of the optimal form of the radio electronic device at the design stage prior to its manufacture.
Analysis of attack surfaces on blockchain systems
(ХНУРЕ, 2020) Stetsenko, P.; Khalimov, G.; Kotukh, Y.
This paper presents a study of attack planessurfaces and possible ways of conducting various attacks on decentralized systems based on Blockchain technology. To accomplish the task, the effectiveness of the attack is studied relative to the plane of its application, namely, relatively: cryptographic designs of Blockchain technology, distributed architecture of systems based on Blockchain technology, Blockchain application context. Several attacks have been identified for each of these planes, including malicious mining strategies, coordinated peer behavior, 51% attacks, domain name attacks (DNS), distributed denial of service attacks, delayed consensus achieving, Blockchain branching, orphaned and obsolete blocks, digital wallet thefts and privacy attacks. An attack by malicious mining allows an attacker to increase rewards by intentionally keeping his blocks closed in order to obtain a longer version of the Blockchain register than the current main version of the register. A 51% attack occurs when a single attacker, a group of nodes, or a mining pool (a combination of miners) in a network reaches most of the total processing power of mining in the system and gets the ability to manipulate the functionality of the Blockchain system. In the plane of DNS attacks, an attacker can potentially isolate peers of the Blockchain system, distribute fake blocks with fraudulent transactions among new nodes, and invalidate transactions. Manifestations of DDoS attacks can vary, depending on the nature of the functionality of the Blockchain application, the features of its network architecture and the behavior of peer nodes. Measures to counter attacks on peer-to-peer peer-to-peer architecture are considered.
Analysis of the effectiveness of the load balancing mechanisms in Software-Defined Networking
(ХНУРЭ, 2016) Tkachova, O. B.; Abdulghafoor Raed Yahya; Hassan Mohamed Muhi-Aldeen
The paper is devoted to analysis of load balancing mechanisms in Software-Defined Networking. Software-Defined Networking has a lot of benefits, however the use of classical traffic engineering principles for traffic management in Software-Defined Network presents a problem. Analysis of the effectiveness of management mechanisms, and in particular, algorithms for network load balancing that enable to take into account the centralised structure and heterogeneous nature of traffic in software-defined networks is proposed.
Another dynamic model of Markovian human-machine-environment system affected by some hazard
(ХНУРЭ, 2013) Naumeyko, I. V.; Alazawi, R. J.
The problem of modeling the behavior of a system and operator, both effected by some hazard is discussed. The cases are considered, when the flow of events generated by the subsystems "machine" and "environment" is the simplest, and also the case when the intensity of the flow is possible to approximate by a flow of Erlang, and when the intensity changes in time.
Application of the theory of formal grammars and the E-nets tools for analysis of correctness of network resources distribution in the NFV infrastructure
(ХНУРЭ, 2016) Duravkin, E. V.; Tkachova, O. B.; Mohammed Jamal Salim
The work is devoted to the development of new methods for the analysis of the correctness of resource allocation in networks with the NFV support. An overview of functional and non-functional requirements for the NFV infrastructure and methods of their verification is presented. As a consequence of the analysis it is proposed to use the E-networks tools for modeling processes of providing services. It is suggested to use the theory of formal grammars as a tool of analysis of the network resources allocation. The algorithm of constructing chains of derivation of the language of R-type for the analyzed model of the E-network is generated and tested
Architecture of network knowledge base of a complex military system
(ХНУРЕ, 2021) Yermoshyn, M.; Poberezhnyi, A.; Onopriyenko, O.; Shuryha, M.
The article examines the architecture of a networked knowledge base and the organizational structure of a complex military-purpose system, which is built when a group of troops (forces) is created and kept in a state where it is capable of solving the tasks assigned to it. This requires a deep study of issues not only of modern tactics regarding the preparation and conduct of hostilities, but also more complex issues of scientific substantiation of the architecture of a networked knowledge base and the structure of a complex military system with a networked knowledge base. The internal representation of knowledge in the knowledge base (formal programmatic and logical content) is advisable to implement in the form of an adjacency matrix, which displays the relationship and relationship between target settings; initial conditions; the resources of the grouping of troops (temporary, material, combat and quantitative composition), their costs and replenishment; rules for the use of resources and the choice of criteria for their distribution. The knowledge base synthesizes a mathematical network model for making decisions, which provides a change (correction) of the structure of target attitudes when replenishing the knowledge base. Tasks solved in the knowledge base: selection of vertices and relations when replenishing catalogs; making changes to the adjacency matrix in accordance with the identified or changed relationships between targets. A necessary element of the synthesis of a mathematical network model for making decisions on the preparation and conduct of hostilities is the construction of the structure of the target systems of the system for a specific situation. A feature of controlling the correctness of knowledge presented in the form of target attitudes is the need for a joint analysis of the entire set of target attitudes and initial conditions in their relationship. For this, the matrix of the relations of target attitudes and the matrix of the relations of initial conditions are combined. The control of the correctness of the knowledge base is carried out when replenishing the knowledge base, it includes: identification of contradictions in the structure of target attitudes when making changes to this structure; search and detection of contradictions in the graph of the semantic network according to available resources and time; checking the completeness of the graph of the mathematical network model; issuance of revealed contradictions to an expert and their elimination. A practical approach to building the architecture of a networked knowledge base and the organizational structure of a complex military system can be implemented during the substantiation of the components and elements of the system when creating a grouping of troops (forces).
CAMELLIA -128-битный перспективный блочный симметричный шифр: методы преобразований, свойства и области применения
(ХНУРЭ, 2003) Горбенко, И. Д.; Михайленко, М. С.; Гриненко, Т. А.
Приводится описание 128-битного перспективного блочного симметричного шифра Camellia. Дается порядок организации прямых и обратных криптопреобразований. Приводятся результаты анализа основных характеристик статистической безопасности алгоритма
Comparative analysis of using transmission and receiving diversity methods in WiMAX technology
(ХНУРЭ, 2009) Loshakov, V.; Vadia, Z.; Hasan, A.
WiMAX o f 802.16e standard is a very promising wireless technology which can support transmission rate about 45Mbit/sec. By adding the fast mobility with the high bit rate WiMAX 802.16e is considered the future o f wireless networks. Because mobile WiMAX is not line o f sight technology it makes the multifading channels interference a very severe problem which challenges the WiMAX performance ability.
Estimation of Expanded Uncertainty in Measurement When Implementing a Bayesian Approach
(2018) Zakharov, I. P.; Botsyura, O. A.
Issues with the estimation of expanded uncertainty in the fi rst draft of the revised Guide to the Expression of Uncertainty in Measurement (GUM) based on the Bayesian approach are considered. Comparative analysis is done of the methodologies that are known and those that are proposed by the authors for estimating expanded uncertainty, based on the current version of the GUM, the GOST R 8.736–2011 standard, and the distribution law of expanded uncertainty. It is shown that the authors’ technique makes it possible to achieve good correspondence of the estimates of expanded uncertainty with estimates obtained by the Monte Carlo method.
Improving the efficiency of LTE using OFDM/OQAM
(ХНУРЭ, 2016) Ali Abdourahamane
Orthogonal Frequency Division Multiplexing modulation technique is used in the downlink of LTE. One of OFDM disadvantages is the outside of guard intervals (cyclic prefixes), which limits the date rate. The basic idea in this article is the increase in the LTE throughput using OFDM/OQAM. Two preamblebased channel estimation methods for OFDM/OQAM modulation systems are presented.
Markovian approach to man-machine-environment systems
(ХНУРЭ, 2012) Alazawi, R. J.
The man-machine system including human being and environment is considered as a queuing system with respect to the How of incoming disasters, all considered models demonstrate markovian properties. The formulas for the system states probabilities are derived in the stable and non-stable cases.
MDES-I28 с таблицами подстановок случайного типа
(ХТУРЭ, 2001) Долгов, В. И.; Руженцев, В. И.; Федотов, М. А.; Мелецкий, А. П.; Пинчук, М. В.
Внимание сосредотачивается на устранении таких слабых сторон алгоритма DES как недостаточная длина ключа и блока данных, а также подверженность атакам дифференциального и линейного криптоанализов. В предлагаемом шифре размер секретного ключа составляет 128 битов, размер информационного блока - также 128 бит. В целях защиты от атак дифференциального и линейного криптоанализов в цикловую шифрующую функцию введена дополнительная нелинейная операция параметрического циклического сдвига. Приводится теоретическое и экспериментальное обоснование этого нововведения
Method of robust algorithm synthesis for separation signals and interference in adaptive antenna arrays
(ХТУРЭ, 2001) Titarenko, L. A.
Method of algorithm synthesis for adaptive spatial separation of signals (signals and interference) with partially unknown parameters is proposed. The synthesized algorithms provide the signal/(mterference+noise) ratio value at each output of the adaptive array that in a given signal-noise environment is close to the potentially accessible one
Methods for contradictions detection in OpenFlow protocol specification
(ХНУРЭ, 2015) Tkachova, O. B.; Abdulghafoor Raed Yahya
Methods of contradictions detectin in the requirements of the OpenFlow protocol specification are offered: the method of successive comparison of formalism requirements and the method of construction of the reachability tree of protocol states graph. The method of sequential detection and collation of all specification formalisms that containe the statement being verified makes it possible to solve effectively a number of narrowly focused tasks. The method for checking the reachability of the graph of states corresponding to the requirements of the specification, which makes it possible to identify all the multiple contradictions within the specification or its fragment.
Optimization of NTRU Prime asymmetric encryption algorithm
(ХНУРЭ, 2017) Kachko, O. G.; Gorbenko, Yu. I.; Esina, M. V.; Akolzina, O. S.
The results of algorithms optimization for the post-quantum mechanism of asymmetric encryption NTRU Prime are given. Namely: module reduction, blinding polynomial calculation, encryption and decryption algorithms. A comparative analysis of different polynomials multiplications is also given
Photonic-crystal fibers gyroscopes
(ХНУРЭ, 2015) Haider Ali Muse
Over the last few decades optical fibers have been widely used in navigation industries owing to their special performance as the best light guide. A fiber-optic gyroscope is one of the applications of optical fibers dependent mainly on the Sagnac effect . It is an important application to the space navigation. It is offered to use the fiber-optic based on photonic crystals with an internal hollow defect. A material medium does not affect on the use of such fibers propagation of optical radiation. Photonic crystal fibers present special properties and capabilities that lead to an outstanding potential for sensing applications
Radio meteor physics – a comparison between techniques from 1945 to the mid-1970's.
(ХНУРЕ, 2020) Hocking, W. K.; Kolomiyets, S. V.
A description of the physics of radar meteors from 1945 to the mid-1970s is presented. Concrete designs of various radars in different countries are presented. Harvard project is the best documented of these early radars, and we will focus on that radar. Application of multi-receiver stations for orbit determination became relatively common, especially with the advent of the IGY in 1957. Canada also built the Springhill Meteor Observatory around the time of the IGY, but of special note was the construction of several meteor radars in the USSR.
S-блоки для современных шифров
(ХНУРЭ, 2012) Долгов, В. И.; Мельничук, Е. Д.
Приводятся результаты оценки эффективности S-блоковых конструкций, применяемых в современных блочных симметричных шифрах. Используется новый показатель оценки эффективности S-блоковых конструкций, который строится на основе оценки числа циклов шифра, необходимых ему для прихода к стационарному состоянию, свойственному случайной подстановке. Показывается, что с высокой вероятностью случайно выбранные S-блоки по этому показателю эффективности будут обладать криптографическими свойствами, не уступающими лучшим известным конструкциям. Предлагаются конструкции случайных S-блоков для шифра Rijndael и шифров, представленных на прошедший украинский конкурс по выбору национального стандарта шифрования
Software quality model based on SQuaRE standards
(ХНУРЕ, 2021) Shtefan, N.; Zaporozhets, O.
Quality is one of the factors that ensure the commercial success and safety of using the software. Quality is understood as conformity the explicit and implicit requirements of various stakeholders. It is necessary to ensure a joint understanding between developers and users, engineers need to understand the meaning of the concept of quality, characteristics and importance of quality for the developed or maintained software. Measurements are the basis for quality assurance. They are the main tool for managing the life cycle of software products, assessing the implementation of plans and monitoring. To quantify quality, it is necessary to measure the characteristics of the software. Standardization provides unification of requirements for quality, its measurement and assessment. The use of standards has many potential benefits for any organization, especially in key areas such as measuring the quality of software products, information and measurement systems. Recognized international standards organizations have published the ISO/IEC 25000 series of standards for systems and software quality requirements and evaluation SQuaRE, which is gaining widespread practical application. The paper discusses a series of international standards SQuaRE, analyzes the relationship between the quality model, quality characteristics, quality measures and a new concept – a quality measure element of the software, presents the measurement of quality based on these standards.
Statement of the problem of assessing instability of passive quantum frequency standards in the pres-ence of an error from the interaction
(ХНУРЕ, 2021) Nariezhnii, O. P.; Grinenko, T. O.; Gorbenko, I. D.
Construction of modern measuring complexes of the coordinate-time support system of Ukraine is impossible without improving mathematical models of quantum standards of frequency (QSF) used in group standards. This work is devoted to the analysis of methods for the stable solution of direct and inverse problems (methods for solving ill-posed problems) in models of the interaction of passive QSF in the process of their comparisons. The priority task is to use these methods for the numerical solution of problems in the design of group QSF and parallel quantum generators of random numbers. Methods for solving such problems are in demand, since they make it possible to create mathemat-ical models of group QSF interaction. These models will enable the design of efficient parallel quantum random number generation devices for high-tech areas of cybersecurity. Varieties of methods such as the method of least squares or the method of the Moore-Penrose pseudo-inverse matrix are used, as a rule when evaluating the metrological parameters of QSF. Robust methods of regularization or fil-tering, for example, the Kalman or Wiener filter method, are used in the algorithms of group standards, due to the insta-bility of the solution. However, these methods do not work in the presence of an error from the interaction of QSF in the process of their functioning in a group standard or in comparisons. The aim of this work is to analyze and substantiate the formulation of the problem of assessing the potential accuracy characteristics of passive QSF in the presence of an error from the interaction. Regularization parameters when determining the state vector of the group standard are found using signals transmitted by global navigation satel-lite systems such as GPS\GLONASS in the local differential correction mode.

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