UDC 621.391
Ilchenko M.Yu., Kravchuk S.O.
Convergence of the Fixed and Mobile Informational-Telecommunicational Platforms and Networks
P. 7–13. Fig. 1. Refs.: 12 titles.
The purpose of this work is to develop the concept of convergence of fixed and mobile information and communications platforms and networks, which provides users with a single uninterrupted service regardless of location or change of access technology allows total use of resources of mobile and fixed networks. With the implementation of this concept raises a lot competing methods and implementation technologies that need its scientific justification. The study produced the following: the driving force in the convergence of information and telecommunication systems is the development of new and improvement of existing services, convergence of fixed and mobile information and communications platforms and networks is the use of common technology resources to the mobile and fixed-line networks to provide the user with a single uninterrupted service regardless of its location, as well as for the organization of a single service and single billing for services.
UDC 621.372.061
Sushko I.O., Rybin A.I.
The Features of Regularization Method for Solving the Electrical Impedance Tomography Inverse Problem by Zones Conductivities Method
P. 14–22. Fig. 5. Refs.: 15 titles.
The features of regularization method of ill-conditioned derivatives matrices from transfer resistances (nodal voltages) on surface zones conductivities solving the Electrical Impedance Tomography (EIT) reconstruction problems are considered. Using the proposed method allows significantly (hundreds of times) reduce the derivatives matrices orders in comparison to the classical phantom model using finite element method that noticeably simplifies the images reconstruction. The calculation examples show that for separate inhomogeneity visualization (geometric localization, size and character definition) it is sufficient to use the no iteration regularization by A. Tikhonov. The iteration regularization should be applied in cases when it is necessary to determine the absolute values of inhomogeneity conductivities with some precision; it requires a large number of iterations. The alternative method (for the last one) is the modification method for matrix inversion. The examples of inhomogeneity (in the center and in the edge of phantom) visualization are shown.
UDC 621.315.615.2
Protsenko О.R., Trotsenko Ye.O.
Calculation of Basic Characteristics of the Humidity Sensor Transformer Oil
P. 23–27.
Тabl. 3. Refs.: 6 titles.
This article outlines the method of calculating the sensor coefficients based on the sensory element of the insulating paper and highlighting features of this calculation. The sensitive element of the sensor belongs to conductometric type of the transducer “moisture–resistance”. The sensor is designed for use in the automated control moisture in transformer oil power transformers and reactors. To calculate the empirical coefficients that define the relation between the resistance of the sensing element sensor, humidity and temperature of transformer oil, use of least-squares procedure has been proposed. We approximate measurements results of electrical resistance sensor as an exponential function of two variables – temperature and humidity oil. Using the proposed method, we calculate the coefficients of samples and humidity sensor. The calculations reveal that measurement of the temperature of transformer oil and impedance sensing element can help determine moisture content of transformer oil in which it is located. We outline the results and recommend how main characteristics of the humidity sensor of this type of transformer oil can be calculated. Hence it can be used as an algorithm for automated humidity control transformer oil of power equipment.
UDC 338.27
Bratus O.V., Podladchikov V.M.
Construction of Multidimensional Models Based on Kalman Filter and Analysis of Estimation Algorithms of its Parameters
P. 28–34. Fig. 4. Тabl. 2. Refs..: 8 titles.
In this paper, we construct the algorithms for estimating mathematical expectation of accelerating the values change of data sample. Simulation modeling is based on these algorithms for the random process. Based on its results, we analyze and choose best algorithms. We show that estimation of mathematical expectation of accelerating values change of data samples for constructed selective sequences of discrepancies does not show better results compared with its estimation based on a full sequence of discrepancies. Adaptive Kalman filter is constructed. Using real values of data, we build the model based on Kalman filter using the best algorithm of estimating mathematical expectation of accelerating values change of data samples, exponential smoothing model, autoregressive model and autoregressive moving average model. We make forecasts using these models. The model based on Kalman filter shows good results for statistical characteristics. Therefore, it is the best model for forecasting characteristics.
UDC 004.021
Kasitskyj O.V., Bidyuk P.I., Korshevnyuk L.O.
Effective Implementation of the EM-algorithm using GPGPU
P. 35–39. Fig. 5. Тabl. 3. Refs.: 11 titles.
The problem of decreasing of running time for the data processing algorithms is very important especially when they are used in real time. For example, in real time image processing, process control systems, speech recognition, etc. The paper considers the possibility of decreasing running time of the expectation maximization (EM) algorithm using modern computing systems. The proposed modified EM-algorithm is aimed at better parallelism for the general purpose graphical processing unit (GPGPU).The experimental results are obtained with solving of the classical problem of Gaussian random variables mixture separation. The proposed implementation of the algorithm was performed on one and two 8-core processor (CPU) setup, as well as on the general purpose graphical processing unit. The graphics processor, because of its abilities for parallel computations and due to the properties of the EM-algorithm considered, showed substantially higher effectiveness in all the computational experiments. Besides, the modified EM-algorithm showed almost two times faster performance on GPGPU than on one or two CPU using large sample sizes (from 5 million values and higher). The lower price of graphics processor is an additional advantage of the approach proposed for such parallel algorithms and GPGPU usage.
UDC 532.3:534.1
Makaseyev A.M., Shvets A.Yu.
Simulation of Delay Effect on Pendulum Oscillations with Limited Excitation
P. 40–45. Fig. 3. Refs.: 14 titles.
We consider the non-ideal dynamical system “pendulum–electric motor” taking into account the delay effect of the electric motor impulse on the pendulum and delay of the medium reaction on the dynamical pendulum state. The system mathematical model is a system of ordinary differential equations with delay. We propose the approaches reducing the mathematical model of the system to a system of differential equations without delay. We investigate the influence of various factors of delay on steady-state regimes of the system “pendulum–electric motor”. The phase-parametric characteristics of the system and dependences of maximum non-zero Lyapunov’s characteristic exponent of the delay are constructed and analyzed. The essential influence of the delay on origin, evolution and extinction of the deterministic chaos in the system is shown. The scenarios of transition from steady-state regular regimes to chaotic ones are identified. We ascertain that it is sufficient to use three-dimensional mathematical models for small values of the delay, whereas nine-dimensional mathematical models should be used for relatively high values of the delay.
UDC 688.321
Skuratovsky R.V.
Modified Algorithm of Shanks with Ordered Blocks
P. 46–52.
Refs.: 12 titles.
Majority of cryptanalytic methods can be modified due to parallel algorithms. One of them is the method of Shanks solving discrete logarithms problem. The main goal of this article is to construct algorithm, which allows parallel calculating all values from low and high pitch tables, to make this search more directed and to put in order all values of table elements. It will allow applying method of blocks searching, separation on the ordered sub-blocks, accelerate applying method of value indexing (or value hash). Parallel optimization and block parallel radix sorting, which became possible due to fast broadcast in duplex mode and mathematical models of algorithm, are the method of solving this problem. Method of parallel vector calculation, using values from BS table as coordinates, was proposed in this work. Optimal lengths of fine pitch and, as a consequence, high pitch were found for the method, which doesn’t use complete order on the range of elements value of such low pitch. Method of improving Shanks algorithm was proposed.
UDC 531.383
Telenyk S.F., Amons O.A., Yefremov K.V., Lysko V.T.
Logical Approach of Software Applications Integration Dealing with the Support of Interdisciplinary Research
P. 53–72. Fig. 8. Refs.: 22 titles.
The paper proposes an approach to the solution of software applications integration problem dealing with the support of interdisciplinary research on the example of the functioning of World Data System using the apparatus of mathematical logic and the theory of artificial intelligence. The authors proposed the overall architecture of the system integration, a formal language for description of existing applications and their functionalities. The inference rules were formulated that define the implementation circuit of application methods and data exchange in the users’ tasks solution process and the algorithm of the mechanism work dealing with the building of the users’ tasks tree solution based on the received output was designed. The proposed approach and the developed models and algorithms are illustrated with the help of the life safety component calculation task and indication of the threat critical values for the analysis of Ukrainian regions sustainable development, and this analysis is carried out annually by the World Data Center for Geoinformatics and Sustainable Development on behalf of the Committee on the systematic analysis of the Ukrainian NAS Presidium.
UDC 537.312.62
Bariakhtar I.V., Gorobets Yu.I., Nazarenko A.B.
Anomalous One-Particle Properties in the Normal State of a Model with dx2-y2 Superconductivity
P. 73–79.
Fig. 3. Refs.: 27 titles.
The main purpose of this study is to investigate the influence of the strong superconducting fluctuations in the d-wave channel on the normal state properties of a simple two-dimensional strongly correlated Fermi-system. We achieve this goal using a thermodynamically self-consistent Baym–Kadanoff conserving Green’s function approximation (formulation is based on a well-defined free energy and conserving particle number, momentum, and energy), which is known to produce reliable results for the s-wave superconductors well beyond the weak coupling limit up to the range where the interaction strength is comparable to the bandwidth of the quasiparticle spectrum. The research shows that pairing correlations above Tc lead to the appearance of a highly anisotropic pseudogap in the electronic spectral function and the destruction of the Fermi surface. We conclude that our results are in remarkable agreement with the available experimental angle-resolved photoemission data on the high temperature superconductors.
UDC 621.923.6:621.318.4:621.002.3
Gavrysh А.P., Кyrychok P.O., Roik Т.A., Vitsuk Yu.Yu.
The Influence of tool composition and Fine Diamond grinding parameters on surface Roughness of composite sliding bearings for printing machine
P. 80–86. Fig. 2. Тabl. 4. Refs.: 21 titles.
The article presents research results on the influence of tool composition and fine diamond grinding parameters on surface roughness of new composite sliding bearings for printing machines. We determine main regularities of surface roughness formation and their dependence on cutting parameters. We discover that granulosity, vehicle material of the diamond disc essentially influence surface roughness parameter Ra. We also determine that the highest values of roughness parameters are ensured at using grinding discs of the synthetic diamond with granulosity of 14–28 mm on thed hard-rubber vehicle. We show that main regularities of fine precision diamond grinding of new composite materials conform at plane, round external and internal grinding. Technological parameters for plane diamond grinding, as well as for round external and internal diamond grinding of new composite friction parts are presented. We make technological recommendations for industry on choosing the grinding tool and cutting parameters. The grinding tool and technological cutting parameters can satisfy high requests for surfaces quality of new composite bearings for printing machines.
UDC 621.793
Stepanchuk A.M., Shevchuk M.B.
Regularities Obtaining Composite wear resistant alloys with self-fluxing alloys on iron based
P. 87–92. Fig. 7. Тabl. 6. Refs.: 13 titles.
We investigate processes for obtaining composite materials with hard granules of refractory compounds and alloys (TiC, ZrC, VC, NbC, Cr3C2, Mo2C, WC (relit), carbides) and self-fluxing iron based alloys to work under abrasion and shock loads conditions. We show the dependence of the structure and properties of the materials studied on their qualitative and quantitative composition. The dependence of the structure, density and hardness of composite materials obtained from the content of self-fluxing alloy of preparation of granules impregnated carcass of hard refractory compounds and alloys. We show that the materials density fully obtained at the self-fluxing alloy content is by 10 % more than necessary to fill the voids formed by granules during their free filling in the form. The material density also depends on the wetting degree of the self-fluxing alloys TTC of the molten material under other conditions. Hardness depends on the CM component content and impregnation time. The highest hardness values are valid for compositions with an average grain size of 257 microns TTS, SFF Content, which is 10 % above optimal settlement, as well as the impregnation time, which is more than 20–30 minutes.
UDC 519.6
Shukayev S.M., Rudakov K.M., Kornev P.A.
Effect of Technological Factors on the Strength of Composite Bolted Joints
P. 93–97. Fig. 4. Тabl. 2. Refs.: 7 titles.
The paper presents calculation results for a double lap bolted joint with elements made of polymer composite material (PCM) for different combinations of such processing factors as size of the bolt hole and tightening torque. These calculations are as close to real situation as possible: three-dimensional and finite-element models are used; the task is solved as thermoelastic and contact taking into account power load, amount of clearance and tightness in holes, tightening torque, friction within the joint. PCM was modeled as 3D-orthotropic material. The calculations were made using FEMAP/NX NASTRAN, version 10.2.0. We made calculations according to the plan of a complete factorial experiment: two factors at three levels, nine combinations altogether. Based on calculation results a regression model was developed. It describes the influence of selected processing factors on the volume of maximum equivalent stress by von Mises. The calculation results indicated that processing factors accompanying production of the bolted joint can significantly influence the stress and deformation state of joint elements. Thus, the maximum equivalent stress in calculations changed from 782 to 1146 MPa. So, the difference exceeded 30 %. We can conclude that the method application to design of bolted joint elements with PCM, particularly in aircraft building, is promising.
UDC 615.837.3
Kyrylova A.V., Tereshchenko M.F., Tymchik G.S., Rudyk V.U.
Algorithm the Automated Estimation of Ultrasound Effect on Biological Tissue
P. 98–102. Fig. 2. Тabl. 2. Refs.: 23 titles.
The article deals with control methods of the biological object using a biofeedback during physiotherapy. The algorithm of the automated estimation of ultrasound effect on a biological tissue is offered. We propose to use the temperature change of skin surface as feedback parameters during ultrasound irradiation and change of saturation change. The common use of parameters of temperature and saturation of biological tissues allows estimating the organism reaction to ultrasound influence, to prevent damage of tissues damage and to obtain the data on tissues adaptation. Based on the proposed algorithm, we analyze the ultrasound effect on a biological tissue. The proposed application allows increasing the treatment efficiency and ensures the ultrasound therapy effect on organs and tissues interaction by using the signal adjusted and controlled in real time according to a defined acoustic radiation dose during the procedure and control maintenance of the secured acoustical contact between a biological tissue and an emitter and temperature measurements of a biological tissue.
UDC 621.378.325
Kolobrodov V.G., Murga H.V., Murga V.V.
Reduction in Luminescence Enhancement Pulse Regime
P. 103–106. Fig. 5. Refs.: 9 titles.
This paper shows that significant energy losses in the Q-switched lasers are due to enhanced luminescence. We experimentally confirm the reduction of the relaxation time of the active centers with a high level of population inversion working levels. We propose a method of reducing losses of luminescence enhancement by using “complex” pump pulses. We analyze the use of “double” and “complex” pump pulses. Excitation of “double” pump pulse can reduce the loss by 7–10 %. “Сomplex” pump pulse provides the increased energy output by more than 20 % compared to “smooth” pump pulse with the same energy. We demonstrate that the increase of energy efficiency of energy conversion in a 'complex' pumping is accompanied by increased stability of output power. Nevertheless, this method is not trivial and requires a lot of correlation spikes of short follow-up period with crystals geometrical dimensions. The proposed method of laser excitation can be successfully used in monopulse laser-radar transmitters stations and remote sensing systems.
UDC 678.686:678.01.537.63
Vilensky V.O., Bardadym Yu.V., Riabov S.V., Dmytrieva T.V.
Thermo-Physical Properties and Specificity of of Nanocomposites Thermal Degradation Cured in Constant External Physical Fields
P. 107–114. Fig. 3. Тabl. 3. Refs.: 19 titles.
By using the methods of DSC, TGA-DTG analysis, we study nanocomposites composition EP– 3 % CdO and EP–3 % (CdO + PAn) cured under standard conditions in constant magnetic or electric fields. We show that these factors affect the segmental mobility of interstitial cross-linked polymer fragments and the specific heat jump. The interaction of external magnetic field only with dipole molecules of the sample EP–3 % CdO causes a partial change in its structure. Analytical processing of DSC thermograms showed that introduction of the polyaniline (Pan) and CdO 3 % vol. into epoxy matrix contributes to reduction of the specific heat capacity of epoxy (EP) in the investigated temperature range and thus causes the segmental mobility growth. PAn, introduced into the reagent mixture (EP–CdO) is forced into the interfacial organic-inorganic mixture layers and contributes to their reconciliation. These data correlate with changes in the activation energy depending on the nanocomposites composition and their сuring conditions. We discover that the CdO catalytic effect influenced the pyrolysis epoxide matrix.