Gulyayev K.D., Kaptur V.A., Tikhonov V.I.
The Principles of Adaptive Interconnection for Open Systems
P. 7–15.
Fig. 6. Tabl. 2. Refs.: 22 titles.
This paper develops the principles of adaptive interaction of open systems that minimize the administrative traffic and provide the integration of diverse traffic in convergent telecommunication networks. To this end, we employ the method of comparative analysis of benefits and open problems applied to the known concepts of NGN networks. We delineate three future generations of NGN networks with specific development stages and implementation of key technology solutions and ideas. We also determine that the potential packet-based technological platform of NGN networks corresponds to the second future generation networks. The expected advantage of this network generation is high quality of service standards. However, some issues remain unsettled, notably the excessive redundancy of administrative traffic running over the network equipments and channels. We introduce novel approaches for adaptive interaction of open systems that considerably reduces the network loading with administrative traffic and provides the flexible mechanism for the integration of various types of services. Based on the proposed multipurpose network meta-protocol, we conclude that methods of fast packet switching of channels in the future third generation networks should be combined.
Askarova A.S., Bolegenova S.A., Maximov V.Ju., Bekmuhamet A.
Investigation of Convective Heat and Mass Transfer in Turbulent Flows in the Burning Presence
P. 16–23.
Fig. 9. Tabl. 1. Refs.: 8 titles.
By employing modern numerical methods, we conduct a comprehensive theoretical study of convective heat and mass transfer in three-dimensional flows of high-temperature reactive environments in the areas of real geometry. We study the processes of heat and mass transfer during combustion of pulverized coal combustion chamber by the example of BKZ-75 Shakhtinsk TPS using 3D modeling technology based on the solution of differential equations of turbulent reacting flows. Crucially, we obtain novel research results on development of modern methods of theoretical, mathematical and computer modeling to study the processes of turbulent heat and mass transfer in high temperature environments in the presence of physical and chemical transformations. Also, we obtain the components distribution of the full speed vector in various sections of the combustion chamber, represent the dependence of the full-speed vector for height of the combustion chamber, as well as obtain the temperature profiles and the height distribution of the combustion chamber. Finally, we establish minimum and maximum values of these variables and show the time history of the characteristics in the investigated volume of combustion chamber.
Bezrodny M.K., Prytula N.O.
The Optimal Characteristics of Ground Heat Exchangers for Heat Pump Heating Systems
P. 24–29.
Fig. 3. Tabl. 1. Refs.: 11 titles.
This paper investigates characteristics of ground heat exchangers for heat pump heating systems. We obtain the optimal ratio between characteristics of ground heat exchanger (tube length of one loop, pipe diameter, and brine velocity in the circuit for heat pump systems) under given conditions of its application (the intensity of selecting heat from soil, thermo-physical characteristics of the heat carrier, temperature conditions of the heat pump system). These optimal characteristics of ground heat exchanger allow providing the optimal degree of cooling brine in the evaporator of the heat pump. Therefore they contribute to obtaining the minimum total costs of electricity of heat pump heating system as a whole. The optimal characteristics of ground heat exchanger mainly depend on soil type, slightly depend on the thermo-physical characteristics of the heat carrier and practically do not depend on temperature conditions of the heat pump system. These relationships can be used for the design stage of the soil reservoir to determine the optimal length of the tube circuit.
Galchenko V.V., Mishyn A.A., Rabchenyuk N.M.
The Analysis of Influence of VVER-1000 TVSA Bias and Manufacturing Tolerances on the Active Core Characteristics During Steady-State and Transients Operation
P. 30–36.
Fig. 8. Tabl. 2. Refs.: 11 titles.
The paper under scrutiny studies the approach of reasonable increase or decrease of multiplication and/or absorption features of fuel and control rods taking into account the fuel assembly bias and manufacturing tolerances. Based on defining conservative initial and boundary conditions, the NPP accident studies are analyzed using this approach. Conservative initial conditions are limiting values (deviations) of reactor systems and equipment parameters defined by the reactor facility design or operational conditions. Hence we choose only those values of parameters which result in the worst consequences for fulfilling the acceptability criteria of the considered initial event. Nowadays defining conservative initial conditions for codes solving thermohydraulic issues is quite well-grounded. However, establishing conservative parameters for 3D core kinetics codes turns out to be rather troublesome since neutron-physical parameters are calculated by the code itself depending on the input data. The possibility of establishing conservative initial conditions deal with preparing few-group macroscopic cross-sections. The research results show the fundamental possibility of influence of bias and manufacturing tolerances at TVS producing on its multiplication features.
Eroshenko V.A., Yarosh T.L.
Synthesis of Fluid with a Large Value of the Temperature Coefficient of Surface Tension–Imperative in the Era of Universal Energy
P. 37–49.
Fig. 5. Tabl. 1. Refs.: 37 titles.
This study briefly discusses the essence of the novel science and technology area - thermomolecular energy. The heterogeneous lyophobic system (HLS) the so called "capillary-porous matrix liquid" is used as a new working fluid. It has a huge surface free energy that can be effectively used to store, to dissipate and to convert energy in the thermo-mechanical systems. We show the important role of the magnitude of temperature derivative of the surface tension of the liquid ds/dT when choosing the functional purpose of the HLS for the developed energy technology. By the example of direct thermodynamic cycle we demonstrate the crucial role of the parameter ds/dT on the magnitude of the thermal efficiency of the thermodynamic cycle and its compactness. Values of these cycle parameters are rising when the value of ds/dT is increasing. It means that the synthesized liquid with preset surface properties (s and ds/dT) will ensure saving of fuel and structural materials in design of energy engines, energy accumulators and energy dissipators. The analysis of the body of scientific literature on the search of such fluids has shown the urgent need for synthesis of a wide range of liquids with ds/dT values. It will allow creating a highly efficient energy technology based on principles of thermomolecular energy.
Golinko I.M.
Optimization of digital Control System from PI-D and I-pd controller
P. 50–58.
Fig. 10. Refs.: 14 titles.
This article considers optimization algorithm of a digital control system from PI-D and I-PD controller on integrated quality criteria. Numerical methods, methods of dynamic optimization systems and digital control theory are used to construct the algorithm. The algorithm proposed allows conducting parametric synthesis of digital modifications of the proportional-integral-derivative (PID) control on integrated quality criteria of merit without the approximation stage of the plant dynamic properties. It allows reducing a lapse of modeling of a control system at the expense of excluding the approximation stage. The interrelation of integrated quality criteria with the character of transients in a control system is numerically investigated. In addition, we demonstrate the dependence of quality transients on the influence channel and modifications of PID controller. We analyze the influence of imperfect PID control on transients’ quality in a control system. We consider the examples of implementing the proposed algorithm at modeling of transients in a control system. The algorithm can be used by developers of automatic control systems for optimizing digital control systems.
Kondratenko N.R., Snihur O.O.
Interval Fuzzy Clustering Based on Alternative Validity Indices
P. 59–66.
Fig. 6. Tabl. 1. Refs.: 15 titles.
The paper studies several clustering validity indices (Kwon index, Xie-Beni index, partition index) in view of the fuzzy parameter. We reveal the pattern of change in indices being researched against the fuzzy parameter change. We introduce an interval type-2 fuzzy clustering method based on combination of three validity indices. The membership values are presented as intervals. It allows preserving completeness of information on a set of their possible values, as well as reducing the influence of each specific index on uncertainty reflected in the result. The latter is achieved by detecting the intersection area of intervals of fuzzy parameter values based on every studied index. The solutions tolerance of results’ abnormal observations is achieved by using the PCM robust clustering method. We analyze the widths of intervals of membership values obtained using the proposed approach in the case of noisy data or data containing abnormalities. Using the proposed approach the countries of the world are clustered relying on their human development characteristics.
Kopets M.M.
The Optimal Control Problem by Singular Linear System with Lumped Parameters
P. 67–72.
Refs.: 7 titles.
In this paper the linear quadratic optimal control problem is considered by singular linear system with lumped parameters. Using the transformation of similarity of singular matrix, the initial system is presented in the form of two subsystems. The Lagrange multiplier method is applied to the transformed system. Relying on this approach we obtain new forms of Euler–Lagrange equations. Furthermore, sufficient conditions are established. By fulfilling these conditions, the optimal control can be unified. Also, we propose the derivation of matrix differential Riccati equations for the above mentioned subsystems. We prove the symmetric property of matrix–valued solutions of Riccati equations. By solving these equations, we obtain the formula for calculating the minimal value of optimality criteria.
Novikova P.A., Novikov Yu.L., Tomashewskiy V.M.
The Motivation Model of Studying the Personality
P. 73–86.
Fig. 5. Tabl. 2. Refs.: 8 titles.
This paper analyzes the impact of motivation on learning and students’ success. Up to date there is no unanimous and clear theoretical view on the motivation phenomenon. The paper considers several approaches to determine motivation and its components. We propose the concept of adaptive e-learning based on the analysis of approaches combining practical advice of Keller’s model and presentation of educational material, given the current psychoemotional state of each student. Also, we apply the model that uses motivational components in the construction of the trajectory of adaptive e-learning. Using a siple test this model allows determining the current psychoemotional state of the student. This test encourages a student to perform tasks which are currently of high priority. It helps creating more comfortable individual conditions for every student’s learning. Moreover, overall performance is improved because students take exams and carry out tests only when they are emotionally prepared for them and thus show better results.
Terentyev O.M., Bidiuk P.I., Korshevnyuk L.A., Prosyankina-Zharova T.I.
Analysis of Investment and Socio-Economic Indicators Using the Methods of Modeling for the Limited Historical Data Sets
P. 87–93.
Fig. 4. Tabl. 7. Refs.: 8 titles.
In this paper, we analyze the development of economic region of Ukraine using statistical data. Specific features of mathematical models construction techniques for analysis and short- and medium term forecasting of regional macroeconomic processes are considered. We study the approaches to constructing mathematical models with short time series and using intellectual data analysis techniques such as principal component method, Bayesian networks, and regression with lagged variables, extended autoregression and trend polynomials. Examples of constructing forecasting models for a regional net product and investments in Cherkasy region are given. Using the models constructed three scenarios are defined for the regional net product development: optimistic, nominal and pessimistic. Finally, we show that even with the nominal scenario for the period till 2015 the region will get enough investments into basic capital that will provide a simple renovation of production. In 2020 the level of extended renovation can be achieved. We also describe the methods used.
Skuratovskii R.V.
Fast Timer Encryption Method
P. 94–101.
Refs.: 10 titles.
A statistical-oriented method of data compression which using non-traditional timer encryption is elaborated. The method uses special weight function. The necessary estimates of compression are developed. Proposed method of multiple system of labels for data compression and decompression method of collection of texts in one area of knowledge. It also was proposed to use a system of multiple labels for a set of texts, which are combined in solid archive. It was proved, that joint unzipping is more effective on the number of operations as a result – on time. Basis for a fundamentally new method of the timer marks on archiving is first proposed the principle of using a set of timer labels which form the shift over another alphabet, labels are in bijection correspondence with blocks of words from text that have a relatively large size m. First time here implemented the principle of self-learning system, which is used in the next step after finding the first prefix label and receipt of accurate data. The probabilistic-statistical analysis and evaluation of the effectiveness of the method are done. This method is used in conjunction with fast timers counters, that have patents on inventions in Ukraine and Russia. The method allowed a virtual software implementation.
Khomenko V.А.
Evaluation Method of Reusable Software Components
P. 102–107.
Fig. 8. Refs.: 12 titles.
The study proposes the evaluation method of reusable software components. The method provides the automated acquisition of properties values based on the directly measured metrics. To fulfill this method, we propose to develop two-level “property-metrics” models that support calculation of properties values based on the direct metrics values. By analyzing aspects of software components based on the 3C-model “conception–construction–context”, the ontology of appropriated properties is developed. The specific technique is proposed to create and to investigate the model properties. This technique encompasses collecting the empirical data of evaluations, checking model dependencies using statistical analysis and modeling the properties calculation. The proposed method enables reducing the efforts for the software evaluation aimed at selecting reusable software components at the non-systematical reuse processes.
Bogyshevsky V.S., Antonevich Ya.K.
Predicting Temperature Regime of Melting Furnace Bath
P. 108–113.
Fig. 2. Tabl. 1. Refs.: 15 titles.
Based on the system approach of the phenomena of heat transfer in a furnace, we obtain relations of kinetics of transition change rate of bath temperature field from the load in the solid metal charge. We uncover the general form of the power expression of the wave process in the bath without integrating differential equations using the experimental data, the ratio of similarity theory, as well as physical modeling. In addition, we obtain criterion equations of heat transfer at fully developed turbulent flow for the internal problem. The heat transfer phenomena are described in the form of the transfer function of the first-order inertial link. The model of heat transfer bath - charge is represented by an object with lumped parameters and used to predict the temperature. The described mathematical model of heat treatment in the induction furnace bath provides high accuracy for obtaining the desired melt temperature. The model can be used in other thermal processes, in which the mixture consists of solid and liquid parts.
Gondliakh O.V.
Finite User Element for Modeling the Processes of Multilayer Structures Delamination in ABAQUS
P. 114–122.
Fig. 9. Tabl. 1. Refs.: 11 titles.
Based on relations of the iterative analytical theory, we develop and numerically apply the stratified 8-nodes finite user element (USER IAT FE) in the ABAQUS environment. The final element allows effectively investigating the processes of nonlinear deformation and failure of spatial multilayer design. Finite element models constructed on the basis of the developed stratified 8-nodes finite user element have persistent rates of solutions convergence both for three-dimensional bodies, thin plates and shells. The ratio of the finite element USER IAT 3D to its length in terms of bending can reach up to 1/500 in the study of spatial structures of thin thickness. In case of stretching it can achieve 1/1000. Convergence rates remain stable for multilayer USER IAT 3D FE when stiffness layers characteristics change for six and more magnitude orders. We conclude that using the stratified 8-nodes finite user element doesn’t lead to increase in the order of resolved equations systems as compared with the standard 8-nodes finite elements.
Makogon Iu.M., Pavlova O.P., Verbitska T.I., Vynar S.A.
Ferromagnetic Resonance in Nanoscaled Fe-Pt Films
P. 123–127.
Fig. 4. Refs.: 7 titles.
The paper under scrutiny studies the influence of phase composition and structure of nanoscaled 10 and 30 nm FePt films on their magnetic properties, specifically on the shape change of ferromagnetic resonance (FMR) lines. The films are deposited on substrate of thermally oxidated (100 nm thick SiO2) monocrystalline Si with orientation of (001). Samples annealings are carried out in the vacuum of ~1,3×10-3 Pа in the temperature range of 100–900 °С for 30 s at each temperature. FMR lines are obtained in magnetic field applied in the film plane after annealing at different temperatures. We establish that the metastable chemically disordered magnetically soft А1(FePt)FCC phase is formed in as-deposited films. FMR line is asymmetric that indicates inhomogeneous magnetic structure of А1(FePt)FCC phase. Films annealings in the chosen temperature range result in transition of А1(FePt)FCC phase to chemically ordered magnetically hard L10(FePt)FCT phase. The processes of diffusion phase formation are accompanied with change of the shape of ferromagnetic resonance lines, their intensities and asymmetric. The dependence of diffusion phase formation processes and change of FMR lines forms from film thickness is not established.
Pirumov A.Ye., Chvertko Ie.P., Shevchenko M.V.
Mathematical Model of Arc Welding with Short Circuits for Development of Quality Monitoring System
P. 128–132.
Fig. 9. Tabl. 1. Refs.: 5 titles.
The paper analyzes the influence of basic parameters of electric arc MAG welding – welding current, arc voltage, electrode diameter and outlet – on electrical processes in welding circuit. Also, we determine basic time parameters of electrode metal transfer for different transfer modes as well as their relationship with basic welding parameters. Furthermore, we develop the stochastic dynamical mathematical model of the welding process. The model includes electrical, physical and welding characteristics of equipment, preset values of welding parameters and electrode metal transfer mode. The model output is presented as electrical process parameters (current and voltage) oscillograms. Statistical tests prove the model adequacy. We determine that it is actually possible to apply the developed model in the quality monitoring system for electric arc welding.
Roik T.A., Dorfman I.Ie.
The Choice of the Operation Mode of Wear-Resistant Details by Analyzing Friction Films
P. 133–136.
Fig. 4. Tabl. 3. Refs.: 7 titles.
The bushing bearings based on wastes of АК12ММгН alloy are produced by powder metallurgy method. We analyze friction films formed on the surface of investigated bushing bearings samples based on wastes of АК12ММгН alloy in the pair with counterface of steel 45 (45–48 HRCe) obtained as a result of tests on friction and wear. We utilize AVMT-1 friction machine to analyze tribotechnical properties of wear-resistant parts based on wastes of АК12ММгН alloy. We demonstrate that this brand new material based on wastes of АК12ММгН alloy has better antifriction properties than the cast material. By using scanning microscopy, we obtain the chemical composition of spectra with arbitrary areas of surface friction. Noteworthy is the fact that results of scanning microscopy correlate with investigated tribotechnical characteristics of wear-resistant parts. We reveal the most efficient operation modes of АК12ММгН material, namely the sliding speed – 1 m/sec; specific load on the friction pair – 5,3 MPa in the air at temperatures up to 120 °C, at which high and stable levels of functional properties of new wear-resistant parts of printing machinery can be achieved.
Donchenko M.I., Byk M.V., Linucheva O.V., Ushchapovskiy D.Yu.
Multistage Galvanostatic Method of Electrowinning Copper from Sulphate Solution of Copper Ore Leaching
P. 137–143.
Fig. 4. Tabl. 2. Refs.: 9 titles.
This paper investigates the process of copper electrowinning from carbonate ore. Copper was leached by sulfuric acid solution. The obtained electrolyte was used for copper electrowinning. We show that step current lowering was the best method to obtain massive cathode deposit or copper foil with 100 % of current efficiency. We make theoretical calculations of the electrolysis process. We demonstrate that the duration of electrowinning period does not depend on metal ion concentration, it rather depends on a, electrochemical equivalent of metal, and cathodes load density in the electrowinning unit. New formulas are proposed for metal ion calculation at step galvanostatic electrowinning. Also, we analyze possible distortions between experimental and theoretical parameters. We show that hydrogen do not evolve at experimental potential, current efficiency decreases in extremely dilute solutions when oxygen reduction current becomes noticeable as compared to main reactions. Experimental cathodic curves allow to measure limiting diffusion currents which correlate very accurately with the ones calculated theoretically.
Kolosov O.Ye., Sivetskyy V.I., Sakharov O.S., Sidorov D.E.
Physical Models of Ultrasonic Influence in Liquid Compositions of Epoxy Polymers. Part 1. Physical Model of the Process of Low Frequency Ultrasonic Cavitation
P. 144–150.
Fig. 3. Tabl. 1. Refs.: 8 titles.
In this paper, we analyze the origin and development of the process of low frequency ultrasonic cavitation in the liquid epoxy oligomer of ЕD-20 brand depending on time of its insonation. We provide the rationale for the physical model of low frequency ultrasonic cavitation in liquid compositions of epoxy polymers. Specifically, it allows choosing effective parameters of this process (frequency, amplitude, intensity) and at the same time ensuring structural integrity of sonicated epoxy compositions. Also, it helps improving technological and operating properties of liquid and hardened epoxy polymers on their basis. We propose to determine effective values of amplitude and intensity of ultrasonic vibrations by studying technological and operating properties of liquid and hardened epoxy polymers. Through experiments conducted, we define the extreme nature of change of these properties from parameters of ultrasonic treatment.
Nagirnyak S.V., Dontsova Т.А., Astrelin I.М., Alekseev А.F., Romanenko U.М.
Synthesis and Characterization of Nanodispersed Powders of Tin Oxide (IV) from Tin Oxalate (II)
P. 151–155.
Fig. 4. Tabl. 1. Refs.: 16 titles.
We synthesize powders of tin oxide (IV) from tin (II) oxalate by thermal method with and without chemical pretreatment. The microstructures of samples are investigated by XR-diffraction and microscopic methods of analysis. We establish that the powders obtained by both methods have a tetragonal structure of rutile. It was determined that the sample obtained by chemical method followed by heat treatment, has a more porous structure than the sample obtained by thermal method. The lattice parameters and size of crystallite of the samples are calculated. The microscopic and XR-diffraction method of analysis shows that sizes of obtained powders are in nanometer range. According to the calculated crystallite size of the samples SnO2 is in the range from 6,9 to 27,4 nm, while according to microscopy it is from 5 to 50 nm.