http://journals.uran.ua/eejet/issue/feedEastern-European Journal of Enterprise Technologies2019-01-10T12:24:10+02:00Makarenko Alinaselezniova.alina@gmail.comOpen Journal Systems<p><span lang="EN-US">Terminology used in the title of the "Eastern-European Journal of Enterprise Technologies" - "enterprise technologies" should be read as "industrial technologies". <strong>"Eastern-European Journal of Enterprise Technologies"</strong> publishes all those best ideas from the science, which can be introduced in the industry. Since, obtaining the high-quality, competitive industrial products is based on introducing high technologies from various independent spheres of scientific researches, but united by a common end result - a finished high-technology product. Among these scientific spheres, there are engineering, power engineering and energy saving, technologies of inorganic and organic substances and materials science, information technologies and control systems. Publishing scientific papers in these directions are the main development "vectors" of the "Eastern-European Journal of Enterprise Technologies". Since, these are those directions of scientific researches, the results of which can be directly used in modern industrial production: space and aircraft industry, instrument-making industry, mechanical engineering, power engineering, chemical industry and metallurgy.</span></p><p><span lang="EN-US">Therefore, the scientists, associated with modern production, have the opportunity to participate in technology transfer to industry, publishing the results of their applied scientific researches. Industrialists, in turn, can draw scientific and practical information from the journal - each in their direction:</span></p><ul><li>specialists in management and computer science - from volumes "Applied Information Technologies and Control Systems", "Mathematics and Cybernetics - Applied Aspects";</li><li>mechanical and design engineers - from the volume "Applied Mechanics";</li><li>production engineers - from volumes "Mechanical Engineering Technology", "Applied Physics", " Materials Science", "Technology of organic and inorganic substances and the Ecology";</li><li>production and power engineers - from the volume "Energy-saving technology and equipment".</li></ul><p><span lang="EN-US">The goal of the journal is to eliminate the gap, which occurs between the rapidly emerging new scientific knowledge and their introduction in the industry, which requires much more time. Industrial enterprises are active subscribers to the "Eastern-European Journal of Enterprise Technologies", and production engineers check the practical value of those scientific and technological ideas, which are recommended for implementation by scientists-authors of the ''Eastern-European Journal of Enterprise Technologies".</span></p><p><span lang="EN-US">The objective of the journal in achieving the goal is forming a "scientific component" of modern technologies transfer from science to industry. Therefore, in the papers, published in the journal, the emphasis is placed on both scientific novelty, and practical value.</span></p>http://journals.uran.ua/eejet/article/view/152793Algorithm for selecting the winning strategies in the processes of managing the state of the system "supplier – consumer" in the presence of aggressive competitor2019-01-09T14:38:34+02:00Olena Dominainfo@eu-jr.euDmitry Luninno_mail@gmail.comOlga Barabasholja8877@yahoo.comOlga Balynskaolga_bal@ukr.netYurii Paidavovo4ka23@ukr.netLiudmyla Mikhailovamihajlovaimesg@gmail.comOlena Niskhodovskaolenas1308@gmail.com<p>The issue examined in this work relates to the search for an optimal pricing strategy by an enterprise-supplier in case it faces a new competitor that offers products at a lower price. The emergence of such a problem necessitates looking for a rational way to reduce its selling price, in order to prevent losing in an aggressive competitive environment, formed by new players entering the market with proposals that are obviously better. To resolve this problem, we have developed an algorithm for selecting the winning strategies based on the estimation of strategic capabilities of a competitor under conditions of uncertainty.</p><p>It has been proposed, in order to assess the cost of a product in the system "supplier-consumer", to apply the concept of the l- level scale. It is shown that, given such a representation, it becomes possible to employ a dimensionless estimation of product pricing, regardless of its type or natural cash value. For a formalized description of relations between an enterprise- supplier and a competing company, it is proposed to use the theory of strategic games, in which a game matrix is built based on universal regression equations. A feature of the proposed solutions is that the value of winning in the game matrix is defined by solving an optimization problem based on the regression equation that describes the impact of transportation costs, profit, and a value-added tax (VAT) on the price of the game. It has been established that, given such a description, the game that is played has a saddle point with the net price of the game z=–0.5. Based on mathematical modelling, it was established that the selection of a supplier company is limited by strategies at which own profit must be close to the average or the minimally possible value.</p><p>We have constructed a predictive model for strategic opportunities of a competitor in the system "supplier-consumer", representing a universal regression equation. Based on it, an adjustment of numerical indicators for the components in product pricing can be made. It is shown that such an adjustment allows the existence of multiple alternatives, neutralizing competitor's advantages. We have substantiated constraints for the solutions derived, related to two factors: an assumption about the accuracy of determining the pricing components of a competitor, and the presence of taxation specificity in international cargo transportation.</p>2018-12-30T23:22:25+02:00Copyright (c) 2018 Olena Domina, Dmitry Lunin, Olga Barabash, Olga Balynska, Yurii Paida, Liudmyla Mikhailova, Olena Niskhodovskahttp://journals.uran.ua/eejet/article/view/152740Characteristics of radiolocation scattering of the Su25T attack aircraft model at different wavelength ranges2018-12-29T14:30:13+02:00Sergey Herasimovgsvnr@ukr.netYaroslav BelevshchukBelevshchuk.76@gmail.comIvan Ryapolovi.ryapolov.79@gmail.comOleksandr Tymochkotimochko.alex@gmail.comMaksim Pavlenkobpgpma@ukr.netOleh DmitriievDmitronik70@i.uaMykola Zhyvytskyin.zhyvytskyi@gmail.comNatalia Goncharenkognika64@gmail.comThis paper demonstrates that mathematical modeling makes it possible to build and explore radiolocation profiles of modern and advanced aircraft. Construction and studying mathematical models based on modern information and computer technology can implement methods for calculating the characteristics of secondary radiation of aircraft at required accuracy, in order to ensure their practical feasibility. We have substantiated a method for the calculation of characteristics of aircraft secondary radiation to analyze the radiolocation scattering of the Su-25T attack aircraft model. The advantage of this method is taking into consideration the integrated representations of classical electrodynamics and shortwave asymptotics. A model of the surface of Su-25T aircraft has been built and a method of mathematical modeling has been constructed. The basic characteristics of radiolocation scattering of aircraft have been substantiated ‒ the effective surface of scattering, the "non-coherent" effective surface of scattering, average and median values for the effective surface of scattering, the distribution laws of the amplitude multiplier of reflected signal. The paper reports results of calculation of these characteristics for the radiolocation scattering of Su-25T aircraft for different radiation frequencies of the probing signal. The obtained results are proposed for application during modernization and design of promising means of radiolocation. The results presented here are useful to assess the feasibility of different structural variants of such tools aimed to detect, track, and recognize aircraft of the same type. Application of the results obtained would make it possible to optimize the design of modernized and promising aircraft in order to reduce their radiolocation visibility. The proposed method is the basis for mathematical modelling of radiolocation characteristics of different types of aircraft under the assigned spatial and time-frequency parameters of probing signals, in order to solve the applied tasks on radiolocation2018-12-29T14:10:52+02:00Copyright (c) 2018 Sergey Herasimov, Yaroslav Belevshchuk, Ivan Ryapolov, Oleksandr Tymochko, Maksim Pavlenko, Oleh Dmitriiev, Mykola Zhyvytskyi, Natalia Goncharenkohttp://journals.uran.ua/eejet/article/view/152713Development of methods to improve noise immunity in the fifthgeneration mobile networks based on multiposition signals2018-12-29T14:30:08+02:00Volodymyr Tolubkoinfo@dut.edu.uaLubov Berkman090289@ukr.netEvgen Gavrylkodut.aspirantura@ukr.netOleg Barabashbar64@ukr.netOlexiy Kilmeninovkilmeninov@ukr.net<p>We have examined technologies for building 5 G mobile networks, which should provide for the creation of ultradense networks in order to render high-quality services. A formalized statement of the problem on synthesis of the optimal signal based on conditions for relative invariance to an additive interference has been prepared. A method for the optimization of signal parameters based on a mean square criterion has been developed. We have proposed to solve the optimization problem by applying the nonlinear programming methods. It has been shown that solving this problem makes it possible to find a signal with the predefined parameters, invariant to deterministic interferences.</p><p>We have developed a method for the optimization of signal parameters based on a uniform criterion. The method is based on determining a totality of signal decomposition coefficients, at which a maximum of the module of an output signal form a demodulator, taken for all values of a random parameter, is minimal. It has been proposed to solve the problem by employing the linear programming methods. Application of this method makes it possible to improve noise immunity in a data transfer system and increase the rate of information transmission along a communication channel.</p><p>Synthesis of the optimal signal with respect to the additive interference has been performed. A given signal renders the maximum possible noise immunity to the system. We have considered a discrete difference transform that possesses a universal property of invariance relative to a wide class of interference.</p>It has been shown that the achievement of an absolute or a relative invariance and the expediency of applying one of the specified methods depend on the characteristics of an interference, the degree of their a priori certainty, as well as the feasibility to form a reverse communication channel. Simulation results have shown that the methods for the formation of an invariant signal, proposed in this paper, could improve a system noise immunity in the communication channel by 5‒7 dB. Introduction of the devised methods would make it possible to increase the rate of transmitted information by 30 %, provided the assigned reliability of data transfer is ensured. Enabling the invariance of an information transfer system would make it possible to build the ultradense fifth-generation networks2018-12-29T13:51:30+02:00Copyright (c) 2018 Volodymyr Tolubko, Lubov Berkman, Evgen Gavrylko, Oleg Barabash, Olexiy Kilmeninovhttp://journals.uran.ua/eejet/article/view/152013Substantiation of quantitative composition of consignments in organizing aggregated shipments in containers2018-12-31T00:14:03+02:00Valeria KorolValeriaKorol1304@gmail.com<p>The task of substantiating quantitative composition of cargo batches during formation of aggregated shipments in containers was studied.</p><p>As a result of the study, a general formulation of the problem of substantiating quantitative composition of consignments during organization of LCL transportations was obtained, and particular versions of its interpretation were defined. To solve local production problems, some technologies have been developed that take into consideration peculiarities of situation and initial information on the planned shipment. The use of these technologies ensures maximum utilization of technical and operational capabilities of the container in formation of aggregated shipments of cargoes. For the first two versions of the task, the technology provides implementation of certain systems of equations and verification of obtained results with regard to the quality of utilization of the carrying capacity and freightage of the container. To solve the problem of the third and fourth versions of the developed mathematical models, implementation of the models ensures maximum utilization of technical parameters of the container due to the optimality criteria reflected in the corresponding objective functions. Therefore, verification of the obtained results with regard to the quality of utilization of carrying capacity and freightage of the container is not required.</p><p>Based on the proposed methodological provisions, experimental studies were carried out that have shown universality of solving problems of optimizing loading of consolidated containers.</p><p>The developed provisions are of scientific importance. They contribute to the development of a theory of transport processes and systems and are of practical interest for commercial departments of transport companies that provide cargo forwarding services. Introduction of these provisions will ensure an increase in efficiency of production activities of representatives of the transport business and will also enable formation of rational systems of cargo forwarding services for cargoes in regional, interregional and international transportation.</p>2018-12-20T14:39:12+02:00Copyright (c) 2018 Valeria Korolhttp://journals.uran.ua/eejet/article/view/151937Optimizing performance of lithiumion battery by nanosilicon addition mixed in LI4TI5O12 anode made using mechanochemicalhydrothermal method2019-01-08T10:09:44+02:00Bambang Priyonobambang.priyono@ui.ac.idAnne Zulfia Syahrialanne@metal.ui.ac.idAchmad Subhanachm037@lipi.go.idFaizah Faizahfaizah474@yahoo.co.idAgnes Gusviantygusvianty@gmail.com<p>Lithium Titanate (Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub> or LTO) is one of the best candidates to replace graphite as anode material in the lithium-ion battery (LIB), due to unwanted solid electrolyte interphase (SEI) layer formation that consumes Li<sup>+</sup> ion and reduces LIB performance and may cause thermal run-away. The ability of LTO to avoid SEI formation and undergo zero-strain during intercalation makes LTO has excellent safety during application. However, the spinel lithium titanate has the low theoretical capacity and poor electronic conductivity. This less conductivity brings limitation to its application. The sol-gel method and combining the LTO with Si that possesses a high theoretical capacity are the key factor to overcome the LTO disadvantages. To attain its high power, safety factor and low-cost fabrication properties, hydrothermal-mechanochemical treatment were used in sol-gel synthesis method in order to outgrowth (Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>)nanostructure. Then, the 5 %, 10 %, and 15 % weight ratio percentage of silicon nano-particle were added into electrode composite in order to enhance the capacity of lithium titanate anode. All samples were characterized using XRD, SEM and TEM. The active anode material LTO/Si nano was coated and prepared into coin cell battery. The assembled coin half-cell used lithium metal foil as the counter electrode. The battery performance was tested using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and charge-discharge (CD).</p><p>The XRD results showed that the obtained compounds of lithium titanate (Li<sub>4</sub>Ti<sub>5</sub>O<sub>12</sub>) crystalline spinel and the impurities of TiO<sub>2</sub> rutile. The SEM micrograph results showed almost uniform morphological structures as agglomerates in most of the samples. While, the TEM image of Si nano had a crystalline phase with the particle size less than 100 mm. However, the presence of unwanted SiO<sub>x</sub> layer was not clearly observed. Addition of Si-nanoparticle could increase the specific capacity to above the LTO theoretical capacity, however, the formation of SiO<sub>x</sub> insulating layer is predicted to be the main hindrance that reduces the effectiveness of addition of Si nanoparticle to the present LTO compound. The hydrothermal treatment of the sample could enhance the performance of nano-composite LTO/Si anode. Based on CD results, the obtained LTO/Si compound possesses the discharge capability up to 12 C.</p><p class="Abstract">The CV and CD results showed the optimum percentage of 10 % wt. Si and best capacity of the sample was obtained at 229.72 mAh/g</p>2018-12-20T11:44:08+02:00Copyright (c) 2018 Bambang Priyono, Anne Zulfia Syahrial, Achmad Subhan, Faizah Faizah, Agnes Gusviantyhttp://journals.uran.ua/eejet/article/view/151929Study into conditions for the interaction between different types of transport at intermodal terminals2019-01-09T14:40:53+02:00Vasyl Petrushovvvpetrushov@gmail.comOleg Shandero.e.shander@gmail.com<p>The study conducted into organization of the interaction among various types of transport at intermodal terminals found that it is necessary to improve the technological process of a terminal to achieve effective functioning of transshipment terminals. Specifically, it is necessary to provide basic requirements, such as continuity, rhythm, parallelism and sequenced-flow of all operations and maximum combination with the high quality of unconditional use. The study proved that achievement of appropriate conditions is possible when using the descriptive model of a two-port terminal. It operates due to the processes of self-synchronization of movement of automated platforms, which transport containers between a road portal and a railroad portal. The study established that we must solve the design problem of creation of perfect computer models for needs of organization of the interaction of various types of transport at intermodal terminals in a combination of descriptive model and analytical model. These models include software components and hardware components that provide conditions for implementation of the concept of self-synchronization movement of forklift trucks. Specifically, the study found that the self-timed control approach provides a greater degree of coordination in operation of a container terminal. That makes it possible to improve the parallelism of processes, that is, simultaneous implementation of events within a system.</p><p>The study showed a possibility for the formalization of processes of self-synchronization by means of Petri nets. This mathematical apparatus is very convenient for modeling dynamic discrete systems and makes it possible to explore the sequential execution of all processes, which occur at an intermodal terminal. Based on the simulation, the study proved that an average container demurrage at a terminal diminishes, which makes it possible to increase processing capacity and to reduce unit costs for processing a container at a terminal.</p><p>Thus, there is reason to state that it is quite possible to develop technologically complete "seaport-railroad portal-automobile portal" terminal structures in various configurations. The type of configuration depends on selected logistics routes for delivery of good. We should apply the method of organization of operation of a two-port terminal for this purpose.</p>2018-12-20T11:42:56+02:00Copyright (c) 2018 Vasyl Petrushov, Oleg Shanderhttp://journals.uran.ua/eejet/article/view/151922Construction and analysis of the model for stochastic optimization of inventory management at a ship repair yard2018-12-31T00:14:20+02:00Igor Petrovfirmness@list.ruMykhaylo Postanpostan@ukr.net<p>A stochastic model of work of inventory management system at a ship repair yard (SRY) has been developed. In order to account for factors related to uncertainties and risks (random moments of arrival of ships at SRY, random volumes of repairs), it has been proposed to apply the apparatus of Markov drift processes for modeling. These processes make it possible to take into consideration the discrete character of change in the number of vessels at SRY, as well as the ongoing character of fluctuation in the inventory level of materials in warehouse. In this case, docks at SRY are interpreted as a queueing system. It is also assumed that the restocking of materials at a warehouse and their utilization during repair of ships is carried out continuously, at constant intensities, but depending on the availability of a material in warehouse. The result of this study is the stated problem on stochastic optimization of intensities in the resupply of materials based on the criterion of minimum cumulative average current expenses of the yard, which also take into consideration the losses associated with additional downtime of ships due to the lack of materials in warehouse during repair. It has been shown that the results obtained are important to the practical operation of SRY supply department as they make it possible to build a strategy for the replenishment of materials in stock at SRY under conditions of time-dependent non-uniformity in the need for ship repairs. From a theoretical point of view, the obtained results demonstrate a possibility of using the apparatus of Markov drift processes to solve various problems on optimal inventory control under conditions of random fluctuations in the demand for materials in warehouse.</p>2018-12-20T11:41:50+02:00Copyright (c) 2018 Igor Petrov, Mykhaylo Postanhttp://journals.uran.ua/eejet/article/view/147585The effect of additive on combustion characteristics and cycle to cycle variations on si engine fueled by gasoline and bioethanol2018-12-29T10:12:50+02:00Setia Abikusnasetia.abikusna@gmail.comBambang Sugiartono_mail@gmail.comRatna Monasarino_mail@gmail.comIqbal Yaminno_mail@gmail.com<span lang="EN-US">Currently, the main energy source is heavily dependent on fossil energy. The current transportation technology also uses fossil-derived energy sources to make vehicle engines are ignited. Also, the electricity that is currently enjoyed by billions of people resulted enormously from the use of fossil energy. Limitations of existing fossil energy sources and the issue of global warming have led many to expand on renewable energy and energy conservation to maintain energy availability. One of an alternative energy source that is currently being developed is the use of bioethanol as a mixture or replacement of fossil fuel. The use of bioethanol (C<sub>2</sub>H<sub>5</sub>OH) as a substitute for a mixture of fossil fuels affects the efficiency of the engine produced by fuel. This study examines the effect of a mixture of bioethanol gasoline (RON 80) on a single-cylinder spark ignition (SI) 125 cc engine that is carried out with variations in fuel mixtures (E0, E5, E10, and E15) with the addition of 0.5 vol</span><span lang="UK"> </span><span lang="EN-US">% oxygenated cyclohexanol and this experimental test is carried out as much as 800 cycles for each fuel mixture, with throttle opening, maintained 100 %, and variations in engine speed at 4,000 rpm up to 8,500 rpm with engine speed increases every 500 rpm.</span><span lang="EN-US"> Engine performance is measured by connecting a machine with a dynamometer, and the variation of cylinder pressure combustion is measured by a pressure transducer. The test results are expected to prove that the mixture of fuel with oxygenated cyclohexanol can reduce COV<sub>IMEP</sub> in the cycle to cycle variations (E10++ which is 4.24 %), so that torque fluctuations do not occur which results in reliable engine performance or vehicle driveability increase, besides that the performance of both power and torque becomes better</span>2018-12-20T11:38:41+02:00Copyright (c) 2018 Setia Abikusnahttp://journals.uran.ua/eejet/article/view/151863Formalization of selection of contract-organizational project delivery strategy2019-01-10T12:24:10+02:00Olexander Bugrovbugrov.oleksandr@gmail.comOlena Bugrovabugrova.olena@gmail.com<p>The formalized system to select a strategy for the implementation of a capital construction project was developed. This is important because an error in making a strategic decision (in an intuitive rather than formalized way) critically affects the further course of events on a project and usually cannot be fixed through the efforts of tactical and operative control. Throughout the whole range of strategies, a number of those, which have characteristic features, and therefore affect specifically project initiators, were determined. Discreteness of the field of alternatives gives a possibility to avoid "fuzziness" in making decisions on the most appropriate strategy. The system became unified through the separation of two elements in it: (1) variable (movable) context that recognizes the features a specific business situation and the specificity of the analyzed project, (2) constant (unmovable) context that reflects the properties of each of the alternative strategies. The business process of comparative analysis involves three stages: assessment of the organization maturity, identification of the market development level, determining project priorities and conformity of a priority complex with the profiles of key contract-organizational models. The first stage gives an answer to the question: "Is it worth following a multi-variant contract-organizational scheme of project management?", the second one solves the problem "Is it worthwhile applying IPD in the current situation?" and the third one gives a response to the question "Which of the contract-organizational models of the analyzed project should be followed?" Thus, the conceptual model reflects all available alternatives of typical strategies that are applied in the international best practices. The total number of key basic contract-organizational alternatives includes 26 strategies. Both the project space, and the field of strategic alternatives are reflected in an integrated coordinate system "time–costs–value–risk" by the conceptual model. The formalized toolset formed the system of the project agreement-organization models COMPAS. The formalized system makes it possible to make unambiguous well-grounded decisions on project delivery strategies, which in practice will lead to better project results.</p>2018-12-19T12:10:05+02:00Copyright (c) 2018 Olexander Bugrov, Olena Bugrovahttp://journals.uran.ua/eejet/article/view/151686Electric heaters based on nanomodified paraffin with selfinstalling heat contact for antiicing systems of aerospace crafts2018-12-29T13:41:41+02:00Alexander ShchegolkovEnergynano@yandex.ruAlexander Semenovsemenov.venture@mail.ruAnna Ostrovskayaostrovskaya-aa@rudn.ruVadym Kovalenkovadimchem@gmail.comImproved effectiveness of ice protection systems of aerospace crafts can be achieved with the development of more effective heaters. Self-regulating electric heaters based on positive or negative temperature coefficient have achieved the highest demand. Development of heaters with such properties involves various matrixes based on cement, glass frit, asphalt mastic, and polymers. Conductivity in such matrixes is governed by metallic or carbon filler. Carbon nanostructures possess the greatest effectiveness. The synthesis method of carbon nanostructures and composites to which they are introduced, the basic properties of resulting electric heaters are determined. To study the effectiveness of electric heaters, a non-contact method of temperature field measurement was used. CNT were synthesized using the Ni/MgO catalytic system, using the thermal decomposition method. CNT morphology was studied using the field emission electron microscope Hitachi H-800. During the investigation, it was found that for the electric heater based on paraffin modified with CNT, the basic specific power was 800±10 % W/m<sup>2 </sup>at an ambient temperature of +10 °C. When the temperature was lowered to -40 °C, specific power increased to 1,600±20 % W/m<sup>2</sup>. Dynamic change of power at different temperatures indicated the presence of a self-regulating effect. Thermal images of the heat contact have revealed that heat radiation stabilizes at 56 °С. The developed heaters can operate at a voltage up to 200 V and possess rational electrophysical and functional parameters, which allow for effective operation in ice protection systems for aircrafts2018-12-19T09:40:40+02:00Copyright (c) 2018 Alexander Shchegolkov, Alexander Semenov, Anna Ostrovskaya, Vadym Kovalenkohttp://journals.uran.ua/eejet/article/view/151650Development of geomodel for concentration determination of hazardous chemicals in the atmosphere2018-12-26T12:50:41+02:00Khudhair Abed ThamerKder.abd@mail.ruA critical analysis of the approaches to the development of a model for determining the concentration of hazardous chemicals (HC) in the atmosphere, which are the basis of computeraided environmental monitoring systems (CEMS) has been carried out. It has been established that the lack of effective functioning of the existing CEMS is determined by the imperfection of the models used to determine the concentration of atmospheric chemical concentration in the atmosphere. In addition, the organic disadvantage of such systems is their departmental affiliation and, as a result, the limited number of potential users. To improve the efficiency of the discussed class of systems, a concept of integrated use has been proposed, within the CEMS framework, elements of information and analytical systems for environmental monitoring, satellite image processing tools, geoinformation technologies, and also mathematical software for calculating the concentration of various types of atmospheric HCs. Building a CEMS based on this concept will provide an opportunity to significantly improve the efficiency of their functioning in the aspects of reducing the time for making decisions, as well as reducing the risk of making wrong decisions. The mathematical support of the CEMS is based on the “Gaussian” statistical model of HC emission, and is intended, along with geographic information technologies, to synthesize a geomodel of groundlevel atmosphere pollution by HCs. As an illustrative example, the situation of the release of chemical waste in the area of Bila Tserkva (Kyiv region, Ukraine) is considered. Theoretical results form the methodological basis for the implementation of the applied information technology for the creation, deployment and operation of a decision support system for eliminating the consequences of an emergency situation caused by the proliferation of chemical water in the atmosphere2018-12-19T09:39:23+02:00Copyright (c) 2018 Khudhair Abed Thamerhttp://journals.uran.ua/eejet/article/view/151816Development of the procedure for forming nonstationary signal structures based on multicomponent LFM signals2018-12-29T14:30:17+02:00Volodymyr Korchinskyivladkorchin@ukr.netMatin Hadzhyievgadjievmm@ukr.netPavlo Pozdniakovpozdner86@gmail.comVitalii Kildishevkildishev@ukr.netValeriy Hordiichukgordiychukvalval@gmail.com<p>Noise protection of existing radio lines with noise-shaped signals and digital types of modulation was studied. Analysis has shown that the use of such signals in conditions of the radio-electronic conflict does not permit to provide necessary level of noise immunity and transmission security of radio communication lines. It was explained by presence of cyclo-conditionality of the carrier oscillation in signals with digital modulation types. Such properties simplify detection and search of signals by means of spectral correlation methods of modern hostile means of electronic surveillance.</p><p>To solve this problem, the use of nonstationary signal structures with variable central frequency and spectral density of power was proposed. A procedure of forming such signal structures by application of the Gram-Schmidt orthogonalization procedure to the ensemble of multicomponent LFM signals with controlled spectral characteristics was developed.</p><p>It was proposed to estimate various signal structures of multicomponent signal by means of phase portraits of summed signals depending on the scaling factor value. This factor’s boundary values at which complexity of the multicomponent signal structure is ensured and degeneration of the process into classical LFM is prevented were established.</p><p>Change of probability of a symbol error in a channel with the use of multicomponent orthogonal signal structures was studied depending on the signal/noise ratio. This makes it possible to estimate potential noise immunity of the radio line provided that the signal/noise ratio is determined by energy indicators of the radio channel and the spectral density of the noise of natural origin.</p>Structural security of the developed signal structures was estimated by means of an energy detector and a cyclo-stationarity detector. It was established that in the case of energy detection, nonstationary signals, and signals of any other type of modulation are equivalent. However, probability of detecting nonstationary signal structures decreased 2–2.5 times compared to other types of signal modulation when using the cyclo-stationarity detector2018-12-19T09:37:49+02:00Copyright (c) 2018 Volodymyr Korchinskyi, Matin Hadzhyiev, Pavlo Pozdniakov, Vitalii Kildishev, Valeriy Hordiichukhttp://journals.uran.ua/eejet/article/view/151806X-ray diagnostics of the structure of nearsurface layers of ionimplanted monocrystalline materials2018-12-29T13:41:49+02:00Ivan YaremiyYaremiyIP@gmail.comSofiya YaremiyYaremiy.S.I@gmail.comMariia Povkhmariia.umantsiv@gmail.comOlesia Vlasiiolesia_vlasii@comp-sc.if.uaVasyl Fedorivfedoriv@pu.if.uaAnna Luсasanlucas09@gmail.comA method for obtaining information on the distribution of the parameters of a crystalline structure in the thickness of a near-surface ion-implanted layer, types and characteristics of radiation defects (size, concentration, etc.) has been developed. The influence of the main diffraction parameters on the rocking curve was established, which made it possible to develop an algorithm for the approximation of the theoretically calculated rocking curves to the experimental ones. It is shown that at small doses of implantation, the value of the extinction coefficient μ<sub>ds</sub> influences most significantly on the intensity of the rocking curves outside the additional oscillatory structure, and the value of the static Debye-Waller factor E influences most significantly on the intensity of the last oscillations of the additional oscillatory structure that correspond to the maximum deformation. To characterize a defective system, it is necessary to analyze the diffuse component using a part of the rocking curve, which is located behind an additional oscillatory structure and in which the contribution of the coherent component is minimal. The method is tested in the analysis of boron-implanted iron-yttrium garnet films. The presented approach provides an opportunity to obtain much of information about the structure of the ion-implanted layer, since it uses the statistical dynamic theory of X-ray scattering, which takes into account the defects of the crystalline structure of any type and size. Also, this approach makes it possible to use all the information contained in the rocking curves and to assess the degree of uniqueness of the specified parameters2018-12-19T09:36:51+02:00Copyright (c) 2018 Ivan Yaremiy, Sofiya Yaremiy, Mariia Povkh, Olesia Vlasii, Vasyl Fedoriv, Anna Luсashttp://journals.uran.ua/eejet/article/view/151751Comparative tests of contact elements at current collectors in order to comprehensively assess their operational performance2018-12-29T13:41:35+02:00Mykola Babyakbabajk_tt@ukr.netVolodymyr Horobetsvgor5650@gmail.comViktor Sychenkoelpostz@i.uaYevhen Horobetsgorobets.eugene@gmail.com<p>We have studied the interaction between contact elements in the pantographs of electric transport under operation at the sections of railroads powered by direct and alternating current. In contrast to known techniques for bench tests, we investigated the mechanism of current collection and wear resistance at the new testing installation over a minimally narrow region of the sliding contact, simulating the phenomenon of a pantograph "cut". This installation can be used both industrially when manufacturing new contact elements and under laboratory setting when studying wear resistance.</p><p>The experimental research confirmed that the wear intensity of contact elements at pantographs depends on current load over a contact area, the magnitude of contact pressure, the area of a contact surface, and motion speed. We have practically proven a possibility to maintain a reliable contact connection in the sliding contact under extreme operating conditions when using a reliable contact material for the current collector pads.</p><p>It has been proposed to use the powder composition BrIG based on bronze, iron, and graphite, for making contact elements for pantographs that could provide for reliable contact when interacting with the contact wire. Application of new and high-quality contact materials affects the tribology and stability of interaction between plates and the contact wire.</p><p>Owing to our study, a possibility has been established to manufacture a reliable contact element BrIG, which would prolong the time of interaction in the contact pair "pantograph at electric transport ‒ contact network".</p><p>The practical significance of this research relates to the proven efficiency of utilizing the new contact material BrIG for electric railroad transport network, in trolley buses and trams.</p>Thus, one can argue about the possibility to prolong the time of operation for the contact pair "pad in a pantograph at electric transport ‒ contact network" by applying the new contact material BrIG2018-12-19T09:35:54+02:00Copyright (c) 2018 Mykola Babyak, Volodymyr Horobets, Viktor Sychenko, Yevhen Horobetshttp://journals.uran.ua/eejet/article/view/151090Substantiation of correctness and advantages of Lenstra factorization method on Edwards curves2018-12-28T19:35:15+02:00Lyudmyla Kovalchuklusi.kovalchuk@gmail.comOleksij Bespalovalexb5dh@gmail.comNataliia Kuchynskan.kuchinska@gmail.comPolina Seliukhbaidenko.polina@gmail.comArtem Zhylinzhylinartem@gmail.comVasyl Tsurkanv.v.tsurkan@gmail.com<p>The factorization problem, which is the basis for many classical asymmetric cryptosystems (RSA, Rabin, and others) and a cryptographically strong generator of pseudo-random sequences (PBS), has been investigated in this paper. The methods that served as prototypes for the Lenstra method were described, the method for factorization of numbers, which is analogous to the Lenstra method on Edwards curves, has been proposed. To substantiate the correctness of the method, an appropriate mathematical apparatus was developed. In addition, an analog of the Lenstra method on Edwards curves was constructed with the use of the presented apparatus; the appropriate algorithm for the factorization of numbers was designed. The correctness of the method and correctness of the algorithm operation were substantiated mathematically; the top analytical estimates of its performance speed, as well as the lower estimates of success probability, have been strictly proved. The advantages of the developed method in comparison with the classical Lenstra method, which applies elliptic curves in the Weierstrass form, were presented and strictly substantiated. A comparative analysis of the new and the classical algorithms was performed.</p><p>Results of the research provided a strict proof that the new algorithm on full Edwards curves, in comparison with the classic one, has some advantages in terms of performance speed, by about 1.5 times. The presented experimental results show that the performance speed increases even larger (by up to 30 per cent) in case the twisted and quadratic curves are used instead of full Edwards curves. It was shown that the assessment of probability of success of the new method increases due to the emergence of new conditions that lead to success of the algorithm that are not satisfied for the classical Lenstra algorithm on Weierstrass curves.</p>The obtained results make it possible to decrease the time required for solving the problem on factorization by approximately 1.5 times, and thus, enable the faster breaking of cryptosystems whose stability is based on this problem2018-12-17T18:06:31+02:00Copyright (c) 2018 Lyudmyla Kovalchuk, Oleksij Bespalov, Nataliia Kuchynska, Polina Seliukh, Artem Zhylin, Vasyl Tsurkanhttp://journals.uran.ua/eejet/article/view/151038Studying fiberreinforced concrete for casting housing parts of pumps2018-12-29T13:41:38+02:00Leonid Krupnikleonkr38@mail.ruKassym Yelemessovelemesov_75@mail.ruSaiyn Bortebayevsbortebaev@mail.ruDinara Baskanbayevabaskanbaeva@mail.ru<p>Many enterprises of the mining and metallurgical industry use pumps transferring aggressive liquids and slurries containing abrasive particles. For the manufacture of pump housings, taking into account their operating conditions, expensive alloy steels with increased wall thickness are used.</p><p>As a result of the study, the analysis of possible materials for the manufacture of fiber-reinforced concrete with the required strength characteristics was carried out. The selection of the optimum ratio of the components, providing, on the one hand, cost minimization of fiber-reinforced concrete and, on the other hand, rational technology for the manufacture of housing parts of fiber-reinforced concrete without additional machining, was carried out.</p><p>It was found that the specified conditions are met to the greatest extent by the mixes containing crushed rubble, quartz sand and ground quartz as aggregate, anchor steel fiber, as well as resin and hardener.</p><p>Theoretical and experimental studies showed that the aggregate must meet the following requirements: it must be three-component by particle size distribution, and the particle size of each component must differ by an order of magnitude from the previous one. This allows obtaining dense mixes by filling voids in large fractions with smaller particles.</p><p>As a result of laboratory studies, it was found that the compressive strength of such hardened mixes is 230...240 MPa.</p><p>It was found experimentally that the optimum fiber additive (steel anchor) should be within 3...5 % by weight.</p>The results of the study allow carrying out calculations of the parameters of pump housing parts with reduced wall thickness, lower weight, and also developing a technology for casting such parts with a high degree of readiness for use2018-12-17T17:57:39+02:00Copyright (c) 2018 Leonid Krupnik, Kassym Yelemessov, Sayn Bortebayev, Dinara Baskanbayevahttp://journals.uran.ua/eejet/article/view/150983Construction of mathematical models for the estimation of signal strength at the input to the 802.11 standard receiver in a 5 GHz band2018-12-29T14:30:11+02:00Dmytro Mykhalevskiyno_Mykhalevskiy@ukr.net<p>The paper proposes mathematical models for the spatial estimation of signal strength at the input of the receiver for the 802.11x family of standards in a 5 GHz range. The models were constructed based on the experimental research into signal distribution for the angular and central location of an access point.</p><p>A special feature of these models is taking the main energy parameter into consideration under a real-time mode, and accounting for the maximally possible number of impact factors. In addition, the permissible limits have been determined for these models, which exert a minimal influence on the effective data transfer rate.</p><p>It was established that for the 802.11 standard, in a 5 GHz frequency range, the rather significant signal fluctuations exist. Depending on the extent to which premises are filled with various objects, the level of fluctuations can amount to δ=±4..8 dBm, subject to the MIMO system availability. The greatest concentration of radiation energy is observed directly at the transmitting antenna at a distance of up to two meters; it subsequently fades on 10...20 dBm.</p><p>It has been established that the presence of MIMO technology introduces a certain heterogeneity to spatial distribution. In this case, there are zones with a lower signal level, as well as zone-bands with a higher level in the presence of multiple antennas. The effectiveness of such a system is maximal in the plane of the arrangement of antennas.</p>The advantages of the derived models for the spatial signal distribution include: the estimation of a signal level in space for any premises; taking into consideration fluctuations in the primary energy parameter, as well as parameters for the transmission medium; accounting for the parameters of premises, as well as the extent to which space is filled with objects. Such models are most effective for application in methods to diagnose and control wireless networks and channels in the 802.11x family of standards<pre> </pre>2018-12-17T17:52:04+02:00Copyright (c) 2018 Dmytro Mykhalevskiyhttp://journals.uran.ua/eejet/article/view/150921Analysis of the efficiency of spacetime access in the mobile communication systems based on an antenna array2018-12-29T14:30:19+02:00Naors Y. Anad Alsaleemnawrasyounis@yahoo.comMohammed A. Kashmoolamohmadkashmola2@gmail.comMykola Moskaletsmykola.moskalets@nure.ua<p class="Default">We performed analysis of effectiveness of various methods and criteria of space-time processing of the signals by an adaptive antenna array with a view to identifying the algorithm suitable for using in arrangement of space-time access to mobile communication systems. It was shown that all methods are based on the assessment of an integrated vector of weight coefficients, included in the reception tract of every antenna element and controlled by certain algorithms.</p><p class="Default">It was shown that recursive procedures that make it possible to correct the vector of weight coefficients in the dynamic situation, including non-stationary signal-interference situation, are more constructive for using in problems of space-time access. This is especially important for communications with mobile subscriber stations and allows reducing the time for processing calling signals due to the rapid convergence of recursive procedures.</p><p class="Default">A comparative analysis of Widrow-Hoff and Kalman-Bucy algorithms was conducted. It was shown that the Kalman-Bucy procedure, in addition to optimality, in complicated signal-interference situation is characterized by maximally short time of convergence to the sustainable state. The convergence of the procedure is ensured on the time interval, allocated for the action of calling signals of subscriber stations in a mobile network.</p><p class="Default">We proposed the model for studying the influence of initial conditions on the effectiveness of space-time access by the parameter of the convergence rate of the algorithm for adaptive space-time signal processing in an antenna array. It is possible to approximate the vector value to the optimal due to configuration of the integrated vector of weight coefficient based on the use of the information about directions of arrival of calling signals of subscriber stations in a mobile network.</p>The results of the calculations of the indicator of the signal/(interference + noise) ratio on the convergence pitch for different algorithms of an adaptive antenna array were obtained. It was shown that it was possible to improve essentially the transitive characteristics of the algorithms for a linear four-element adaptive antenna array due to the successful initial choice of the value of the integrated vector of weight coefficients. This made it possible to increase the value of the signal/ (interference + noise) ratio at the outlet of an antenna up to 4 dB2018-12-13T19:25:25+02:00Copyright (c) 2018 Naors Y. Anad Alsaleem, Mohammed A. Kashmoola, Mykola Moskaletshttp://journals.uran.ua/eejet/article/view/150903Practical implementation of the Niederreiter modified cryptocode system on truncated elliptic codes2018-12-28T19:35:21+02:00Serhii Yevseievserhii.yevseiev@hneu.netOleksii Tsyhanenkooleksii.tsyhanenko@hneu.netSerhii Ivanchenkosoivanch@ukr.netVolodymyr Aleksiyevaleksiyev@gmail.comDmytrо Verhelesdndi_vdd@dsszzi.gov.uaSergey Volkovgreyw@ukr.netRoman Korolevkorolevrv01@ukr.netHryhorii Kotsdekanstei@gmail.comOleksandr MilovOleksandr.Milov@hneu.netOlexander Shmatkoasu.spios@gmail.comOn the basis of the practical implementation of the classic Niederreiter scheme for non-binary codes, a pattern has been identified for practical implementation –fixing the admissible position vectors of the plaintext transformation based on equilibrium coding. The obtained set of position vectors of the error vector with a fixed set of masking matrices (the recipient's private key) allows us to obtain the algorithm for decoding the classical Niederreiter crypto-code scheme on non-binary codes. For this, a modification of the crypto-code system (CCS) is necessary. It is proposed to use the additional parameter of key data – the initialization vector (the set of invalid position vectors of the error vector). To counter the Sidelnikov attacks, it is proposed to use modified (shortened) algebraic-geometric (elliptic) codes (MEC). For this, it is necessary to use the second additional initialization vector (the set of positions for shortening the error vector). Based on the modification of the classical Niederreiter scheme on non-binary codes, applied algorithms for generating and decrypting a cryptogram in the Niederreiter modified crypto-code system based on modified (shortened) elliptic codes and software are proposed. To confirm the profitability of the proposed crypto-code system, the results of the comparative evaluation of energy consumption for the implementation of the classical Niederreiter scheme on elliptic codes and the implementation of the proposed system on modified elliptic codes are presented. The results confirm the possibility of practical implementation of the Niederreiter crypto-code system based on the proposed algorithms. At the same time, the required level of cryptographic strength of the crypto-code system, protection of the cryptosystem against the Sidelnikov attacks and an increase in the rate of cryptographic transformations by 3-5 times compared with the classical Niederreiter scheme are guaranteed2018-12-13T19:23:26+02:00Copyright (c) 2018 Serhii Yevseiev, Oleksii Tsyhanenko, Serhii Ivanchenko, Volodymyr Aleksiyev, Dmytrо Verheles, Sergey Volkov, Roman Korolev, Hryhorii Kots, Oleksandr Milov, Olexander Shmatkohttp://journals.uran.ua/eejet/article/view/150870Application of the basic module's foundation for factorization of big numbers by the Fеrmаt method2018-12-28T19:35:18+02:00Stepan Vynnychukvynnychuk@i.uaYevhen Maksymenkomaksimenco@gmail.comVadym Romanenkoroma_38@ukr.net<p>The Fermat method is considered to be the best for factorization of numbers N=p×q in case of close p and q. Computational complexity of the basic algorithm of the method is determined by the number of check values of X when solving equation Y<sup>2</sup>=X<sup>2</sup>‑N, as well as by complexity of the arithmetic operations. To reduce it, it is proposed to consider admissible those of test values X, for which (X<sup>2</sup>–N)modbb is quadratic residue modulo bb, called basic. Application of basic foundation of module bb makes it possible to decrease the number of check X by the number of times, close to Z=bb/bb<sup>*</sup>, where bb<sup>* </sup>is the number of elements of set Т of the roots of equation (Ymodb)<sup>2</sup>modb=((Xmodb)<sup>2</sup>–Nmodb)modb, and Z is the acceleration coefficient.</p><p>It was determined that magnitude Z(N, bb) is affected by the value of residues Nmodp (at p=2, Nmod8 residues are used). The statement of the problem of finding bb with a maximum Z(N, bb) at restrictions for the amount of memory of the computer, where exponents of prime numbers – multipliers bb – are determined, and the method of its solution were proposed.</p><p>To decrease the number of arithmetic operations with big numbers, it was proposed that instead of them to perform the operations with the values of differences between the nearest values of elements T. Then arithmetic operations of multiplication and addition with big numbers are performed only in rare cases. And if we derive the square root of X<sup>2</sup>–N only in cases, where the values of (X<sup>2</sup>–N)modb will be quadratic residues for many foundations of module b, other than bb, the computational complexity of this operation can be neglected.</p>It was established that the proposed modified algorithm of the Fermat method for numbers 2<sup>1024</sup> ensures a decrease in computational complexity compared to the basic algorithm on average by 10<sup>7</sup> times2018-12-13T19:22:39+02:00Copyright (c) 2018 Stepan Vynnychuk, Yevhen Maksymenko, Vadym Romanenko