Voitenko Iu.Iu.
On Transport Layer Retransmission Timeout in Ad Hoc/Manet Networks
P. 7–10.
Fig. 1. Tabl. 4. Refs.: 5 titles.
This article describes a key aspect of providing the reliability of the network transport layer TCP/IP based networks, such as a retransmission timeout. We are improving the efficiency of the transport mechanisms by adapting the retransmission timeouts of the transport protocol to the conditions of operation of self-organizing radio networks. The basis for the proposed new method for determining the retransmission timeout of packets is to calculate the timeout for each route individually, rather than the cumulative timeout packet-receipts. This allows for a self-organizing networks to calculate such a number of timeouts, how many routes found up to the final destination. It is proved that such an approach can significantly reduce the waiting time in the case of packet loss and retransmit, and thus increase the overall throughput of the transport connection.
Kryzhanovskiy V.I., Kuzmichev A.I., Chaplinskiy R.U.
Effect of thin Film Dielectric Barrier Parameters on the Ozonizer Characteristics
P. 11–15.
Fig. 5. Refs.: 7 titles.
The aim of this paper is to investigate the influence of properties of thin films and glass dielectric barriers (thickness from 8 um to 1 mm) on the ozonizer characteristics and choose the best. This paper presents experimental results on the effect of parameters of dielectric barriers made from polymeric materials (Lavsan, Teflon), quarts glass as well as SiO2 thin films, deposited by the reactive electron-beam vaporization on the ozonizers characteristics. Experimental results show that the dielectric barrier breakdown voltage decreases with roughness of electrode surface under dielectric. Also, experimental results show that the use of the dielectric barriers with SiO2 thin films and polymeric materials leading to the increase of ozonizes efficiency. But polymeric materials show low life cycle. That’s why SiO2 thin film deposited on a polished electrode surface is the best dielectric material to use in ozonizers.
Ksyonzenko P.Ya., Narytnyk T.M., Hymych P.V.
Construction Features of City Data Transmission Network Based on the MITRIS Technology
P. 16–29.
Fig. 9. Tabl. 4. Refs.: 7 titles.
This paper presents possibilities of constructing the city data transmission networks on the microwave integrated multimedia systems of a multiservice radio access (MITRIS technology) basis using the cable standard DOCSIS modems. We describe and propose parameters of the system and its constituents: base station, repeaters, secondary concentrators, and the user's station. Also, we consider the competitiveness and specifics of implementing the data transmission city networks based on the MITRIS technology in the range of frequencies 10,15–10,30 and 10,50–10,65 GHz. We show that the approaches proposed to construction of such networks permit minimizing the influence on ecosystems, reducing the consumption of materials and energy.
Bezrodny M.K., Halan M.A.
Thermodynamic Efficiency of Heat Pump Systems of Air Heating
P. 30–35.
Fig. 7. Refs.: 7 titles.
This article discusses the two most common heating systems based on air heat pumps: air heating scheme of ventilation and the so-called split-system Since the literature lacks data on sound analysis of the peculiarities of different air heating systems, their thermodynamic efficiency under different operating conditions, the article is devoted to addressing these issues. It provides an analysis of heat pump systems, air heating, the resulting values of energy utilization for such systems, given the comparative analysis of the two most common heat pump systems using heat air. As a result, conclusions regarding the efficiency of heat pumps in heating systems, air, which showed that the heat pump circuit air heating with ventilation hardly inferior to its effectiveness as a circuit split-system. These results will be used for comparison of air heating systems with similar but more complex systems.
Brzhezitsky V.A., Scherba A.A., Podoltsev A.D., Trotsenko E.A., Shevchenko S.Yu., Garan Ya.A., Atarod S.
A Study of the Causes of Electric Overlapping of the Middle Phase Insulator String of the Overhead Power Line
P. 36–41.
Fig. 6. Refs.: 5 titles.
Two possible causes of electric overlapping of the middle phase insulator string are taken into consideration: the design defect of cap-and-pin insulator and the tangent tower impact on electric field intensity near insulator string. Experimental and theoretical researches of an electric field of cap-and-pin insulator strings of 330 kV overhead power line were carried out. The insulator string's three-dimentional electric field was calculated using finite element method. By results, for the first time it was shown that frequent overlapping of middle phase insulator string is caused by increase of voltage drop on middle phase last insulator, in comparison with that one of the other phases. Ways of decreasing of non-uniformity of an insulator strings intensity distribution of the middle phase are offered.
Bidyuk P.I., Trofymchuk O.M., Fedorov A.V.
Informational Decision Support System for Forecasting Financial and Economic Processes Based on Structural and Parametric Adaptation of Models
P. 42–53.
Fig. 5. Refs.: 15 titles.
A concept is proposed for solving the problem of adaptive forecasting that is based on the system analysis methodology and combined use of preliminary data processing techniques, mathematical and statistical modeling, forecasting and optimal state estimation of the processes under study. The cyclical adaptation of a structure and model parameters on the basis of a set of statistical characteristics of a process under study provides a possibility for reaching high quality estimates of forecasts with condition that data is informative. The study performed gives a possibility for statement that the methodology proposed could be applied to analysis of a wide class of real life processes.
Golinko I.M., Kubrak A.I., Tregub V.G.
Synthesis of Control System on Integrated Quality criteria
P. 54–59.
Fig. 8. Refs.: 9 titles.
The optimization algorithm of a digital control system on integrated quality criteria is considered. The offered algorithm allows to build parametrical synthesis of a digital proportional-integral-derivative control on integrated quality criteria. The integrated quality criteria of interrelation with character of transients in a control system is numerically investigated. Dependence of quality transients on the influence channel is shown. The examples realization offered algorithm are considered at modeling of transients in a control system. The algorithm can be used by developers of automatic control systems for optimization of control systems.
Kirik O.E., Klimenko V.M., Ostapenko V.V., Iakunina I.L.
Dynamic Models with a Generalized Conservation Law to Control the Flows Distribution in Networks
P. 60–66.
Refs.: 15 titles.
This paper considers general principles for constructing and investigating mathematical models of natural resources flow distribution along the energy network. Based on classical and generalized conservation laws we construct the complex of dynamic models for flow distribution in networks taking into account the ability to create reserves of energy resources and the uncertainty of information objectively inherent in large power systems. Also, we exemplify the issues of water traffic control in the channels of water irrigation systems and gas pipelines. The proposed approach is the most useful for long-term planning, but can be used in cases of the operational control of flow distribution in distribution systems subject to periodic measurement and specification of certain network parameters.
Romanenko V.D., Reutov O.А.
Optimal Decision-Making on the Stabilization of Hryvnia/Dollars Course on the Basis of Mathematical Models with Multirate Sampling
P. 67–73.
Fig. 9. Tabl. 1. Refs.: 10 titles.
The present paper describes the development of the model structure of the hryvnia/dollar in the ARMAX form. The model inputs are seven factors and one control, which are measured at different time intervals. This allows us considering the model with multirate sampling, where the output coordinate and control are measured every ten days, and the factors in their turn have three time rates: every ten days, monthly and quarterly. Based on this model, we propose and test the approach to the optimal decision based on the optimality decision-making in the form of the generalized variance. To simplify its usage, we derive an equation for determining the optimal solution based on the proposed optimality criterion. Relying on historical data, we analyze the reduction of the generalized variance for the historical horizon of testing in general, which suggests the possibility of managing the exchange rate hryvnia/dollar and reducing the fluctuations of the output coordinate.
Romanuke V.V.
Continuum of the Projector Optimal Decisions in Antagonistic Four-Unit Model of Distributing Resources under Two Incorrectly Evaluated Uncertainties and the Corresponding Game Value
P. 74–78.
Refs.: 10 titles.
There is considered a problem of resources optimal distribution with removing uncertainties in the normed cross-section squares of the four-unit construction, where the minimax procedure is particularized for the case of the incorrectly evaluated single left and single right endpoint of segment uncertainties. The resources distribution model under these conditions is the antagonistic game on six-dimensional hyperparallelepiped of Cartesian product of the set of all possible normed loads and the set of all possible decisions of the projector. The theorem on continuum of the projector optimal decisions in the corresponding antagonistic model has been proved. Each element of this continuum may be used for the final producing of the four cross-sections.
Yasinsky V.V.
The Issue of Forecasting and Control of the Knowledge Evolution in Complex Training Systems
P. 79–83.
Refs.: 15 titles.
Relying on studies of systematic approach, we investigate the issue of forecasting and control for the model describing the knowledge evolution in complex training systems. We obtain the substantial mathematical results for the proposed nonlinear evolution equation. These results depend on conditions of parameters of a non-smooth function of the reaction system that ensures saving a fixed level of knowledge, the terms of the dissipation at this level, the existence of global attractor, and the ability to approximate the optimal control process of the evolution of educational knowledge.
Andreyev I.A., Komkina N.V.
A Process of the Laminar Convectional Mixing of Fibroconcrete is at Vibroextrusion in Round Circular Channel
P. 84–88.
Fig. 5. Refs.: 14 titles.
We clarify features of the process that occurs in a round circular channel to assess the degree of the components mixing in fiber-reinforced concrete compositions in a modern vibroextruders. We also consider the process of simple mixing in a laminar flow in the absence of diffusion occurring in such a channel. When reviewing the process we utilize the phenomenological approach, which takes the fiber-reinforced concrete composition for a homogeneous isotropic medium. We solely generalize explanations on the composition structure. Moreover, we take into account that vibrating fiber-reinforced concrete compositions in vibroextruders are pseudo Newtonian systems. We introduce analytical formulas for calculating displacement deformation, functions of allocation of deformation and residence time of composition in a round circular channel. We also found that round circular channels as compared with planes, rounds and conical provide significant reduction in nonuniformity of allocation of displacement deformation of the channel cross section. In its turn it improves mixing and hence properties of the composition throughout its volume conducing to receipt of high quality products.
Arshuk M.V., Khizhnyak V.G., Loskutova T.V., Pogrebova I.S.
The Corrosion Resistance of Chrome-calorized Steel 12Х18N10T
P. 89–95.
Fig. 4. Refs.: 16 titles.
The paper under scrutiny presents the research results of chrome-calorized steel 12Х18N10T. Moreover, we demonstrate that it is possible to obtain complex chrome-calorized coating with titanium nitride TiN on the surface of the steel 12Х18N10T. To obtain this coating, we combine two processes: physical vapor deposition of titanium nitride and diffusion of chrome-calorizing conducted through the powder method in containers with fusible gate under reduced pressure at 1050 C for 3 hours. Hence we obtain the structure, phase and chemical composition of coatings. We determine the effect of the barrier layer of titanium nitride TiN on the composition and structure of the coatings. Chrome-calorized coating on the steel surface 12Х18N10T helps improve its corrosion resistance in these environments: acetic acid at 4,3, 5,3 and the water in the soda is 3,2 times. The coatings obtained are promising for using in friction and wear, high temperatures and corrosive environments.
Kramar H.M., Sushynskyi V.I., Isaiev Ye.O.
Specificity of Polycarbide Sintering Based on Hard Alloys with Fine- and Nanodisperse Binder
P. 96–101.
Fig. 4. Tabl. 2. Refs.: 17 titles.
In this paper, we investigate the kinetic patterns and mass transfer mechanisms at different sintering stages of the polycarbide based on hard alloys TiC-5NbC-5WC with NiCr binder (the ratio of Ni:Cr 3:1) composed of fine- and nanodisperse nickel of 7,5, 13,5 and 18 % (mass.). We show that adding 18 % of (mass.) nanodisperse nickel into the alloys activates sintering allowing to reduce the sintering temperature to 1350 С and the isothermal soaking time to 20 minutes. The grain boundary diffusion mechanism for all alloys is implemented at the stage of solid phase sintering. At the stage of liquid phase sintering for alloys with nanodisperse nickel recrystallization occurs mainly by surface diffusion, while with fine nickel it occurs by the grain boundary diffusion.
Loboda P.I., Karpuschewski B., Dübner L.G., Chaika D.V.
The Effect of Anisotropy of the Microstructure Reinforced Boride Ceramics on the Adhesive Bonding Strength of Titanium Nitride Coatings
P. 102–107.
Fig. 4. Tabl. 1. Refs.: 5 titles.
In this article, firstly we investigated the contact interaction of the tool material made of reinforced boride ceramics and covered with titanium nitride with a diamond indenter with various loads. We studied the influence of the microstructure nature of ceramic and loading conditions on the adhesion strength of the titanium nitride coating. We determined that the magnitude of the friction force depends on the surface microstructure of the composite material. It is satisfactorily correlated with the area of contact interaction between the indenter and the surface of the composite coated with a film of titanium nitride. Moreover, we established that the boride reinforced ceramic coated with TiN on its mechanical properties are not inferior to the best traditional ceramic tool materials.
Makogon Iu.M., Pavlova O.P., Verbitska T.I., Vladymyrskyi I.A.
The Influence of Annealing Conditions on Structure and Magnetic Properties of Nanodimensional Fe50Pt50 Film on Planar SiO2(100 nm)/Si(100) Substrates
P. 108–113.
Fig. 5. Refs.: 8 titles.
It is studied the influence of annealing conditions in temperature range of 300– 900 °С on formation of magnetic-ordered L10(FePt) phase in nanodimensional Fe50Pt50(15 nm) /Ag(3 nm)/Fe50Pt50(15 nm) film composition (NFC) on planar SiO2(100 nm)/Si(100) substrate. It is investigated its structure, morphology and magnetic properties. It is shown that the formation of L10(FePt) phase occurs at annealing 700 С for 30 s and heating rate of 5 С/s. Amount of L10(FePt) phase increases with increase of annealing temperature. It is accompanied with formation more grains with necessary (001) texture in comparison with grains with (111) texture. It is established that NFC under investigation is magnetic-anisotropy. Ratio of magnetic remanence Mr to the saturation magnetization Ms about 1 is obtained after annealing at 700 С in magnetic field applied parallel to the film plane with dominant corresponding orientation of easy magnetization axis. At higher annealing temperatures it is occurred reorientation of easy magnetization axis perpendicularly to the sample plane.
Pelykh V.M.
The Calculation of Fatigue Lifetime of Constructional Aluminium Alloys under Asymmetric Tension-Compression Loading by the Method of Equivalent Stress
P. 114–119.
Fig. 1. Tabl. 1. Refs.: 8 titles.
The paper considers the problem of calculating the fatigue lifetime and creating the S-N curves of constructional aluminium alloys under high-cyclic asymmetric tension-compression loading. The solution is based on the equivalent stresses conception. Also, we calculate the lifetime of constructional aluminium alloys. Our results satisfactorily conform to the experimental data obtained. These methods can be further employed to calculate fatigue lifetime of any constructions’ elements working under the asymmetric tension-compression.
Sorochenko V.F., Chernega D.F., Kud P.D., Ivanchenko D.V.
Nanotechnologic Bases of ZrF4 Application to Increase the Strength of Cast Aluminum Alloy AK12M2
P. 120–124.
Tabl. 1. Refs.: 15 titles.
In this paper, we demonstrate that B.B. Gulyaev’s quasi-static representations of macroprocesses in cast aluminum alloys should be further elaborated. We theoretically justify and experimentally confirm the quantitative influence of ZrF4 nanoparticles on determining its optimal entry and strength of the alloy AK12M2. We propose physical and chemical foundation for the salvation model of ZrF4 nanodistribution, notably particles of ZrF4 modifier in a state of statistical lattice of cast aluminium alloy. It means that one molecule of the modifier on a cluster-solvate complex consists of n2 atoms of the solvent metal (aluminum). In addition, the model takes into account the disparity of coordination numbers of Zr (8) and Al (12). Through experiments conducted, we prove the model for calculating the optimal amount of input into the alloy compounds ZrF4 and its influence on the durability of AK12M2 with a relative deviation of 1–10 %.
Jachno O.М., Strutinsky S.V.
Hydrodynamics of Stream Flows in Cracks of the Managed Hydrostatical Spherical Hinges
P. 125–131.
Fig. 7. Refs.: 11 titles.
In this paper, we propose the construction of hydrostatical spherical hinge with the stream system of adjusting the sphere position. Also, we consider the flow features in the flowing part of hinge. The method of calculating the hydrodynamic parameters of stream flows in cracks of hydrostatical supports enables studying the hydrostatistical spherical hinges. Moreover, we determine the fields of speeds, pressures, tensors of tensions and tensors of deformation speeds in the whole volume of the crack of hydrostatical supports. We find analytical dependences for calculating the hydrodynamic parameters of flow. Through experiments conducted, we study the second vortical flows which appear in a crack at interaction with the limited stream flows. Finally, we define the quantitative characteristics of the second vortical flows and the cause of their formation.
Mikheenko L.A., Timofeev O.S.
Metrological Characteristics of a Diffuse Emitter Based on the Integrating Sphere with Light-Emitting Diodes
P. 132–138.
Fig. 10. Tabl. 1. Refs.: 9 titles.
The aim of this work is developing, with the help of the developed numerical method, analyzing the impact of the main elements of DV on its metrological characteristics and development on this basis, recommendations for designing next-generation high-precision IS. To identify the main parameters of a spherical surface that affect on formed brightness field. It is shown that in all cases the position of the element is non-uniformity of the most significant factor of influence on the brightness distribution of the output aperture, the fluctuations of other design parameters affect the irregularity is much smaller. It is shown the influence of the parameters of the radiation source on the characteristics of DV. It is established that the source size is less affected by the unevenness of brightness than that position of the source. Descry the prospects for improving the metrological characteristics of the IS by using brightness LED belt type. The integrated brightness of the DV, may not exceed 950W/(srm2) with uneven brightness field better than 0,5 % in the spectral range of 0,4–0,7 microns.
Deshko V.I., Shevchenko O.M.
Structural Analysis of Energy Consumption and Energy Efficiency in Education
P. 139–147.
Fig. 8. Tabl. 2. Refs.: 15 titles.
The paper studies the structural analysis of the energy consumption facilities in the area of education. The following areas are included: analysis of energy use, specific consumption of energy facilities, as well as identifying factors that influence the energy consumption of higher education institutions. We determine the specific energy consumption using the data on energy consumption, total areas of buildings and the difference between weather conditions of actual and reference years. Furthermore, we compare the values of specific energy consumption with world analogues and national regulations. And we further evaluate the energy performance objects. Finally, we classify the universities in terms of “specific energy consumption” to further elaborate the approaches and methods for assessing the energy efficiency of universities and their buildings, as well as for developing the energy management system of education in general.
Barbash V.A.
Substantiation of Processes Efficiency Methodology Assessment of Plant Material Delignification
P. 148–153.
Fig. 2. Tabl. 3. Refs.: 10 titles.
The paper analyzes the consumption and production of paper and cardboard during the years of Ukrainian independence. We summarize the experimental data for obtaining laboratory samples of cardboard and paper products with using its fiber composition of pulp from non-wood plant materials. It is shown that to increase the consumption of paper and paperboard per capita to expand the capacity of enterprises to obtain pulp from various sources of plant material, particularly from non-wood plant materials. Found that the use of non-wood pulp from non-wood plant materials in the composition of different types of paper and paperboard expands raw materials of the industry, improves the quality of the final product meets all requirements and standards.
Golembiovskyi A.O., Kovalchuk I.A., Kornilovych B.Yu., Zhdanyuk N.V.
Remediation of the U(VI) Ions from Waters Using Organic Clays
P. 154–158.
Fig. 4. Refs.: 15 titles.
This paper studies characteristics of sorption of anion and cation forms of uranium (VI), as well as uranium carbonate complexes. By modifying the natural clay mineral montmorillonite by cationic surfactant, we obtain sorbents for uranium remediation from waters. Relying on the methods of XRay diffraction, IR-spectroscopy, turbidimetry, and adsoption, we determine sorptive properties of the natural and modified samples. Furthermore, we prove the effectiveness of using these methods for uranium remediation from waters.