Bunin S.G., Dolzhenko D.O.
Estimation the Sensitivity of Receiver that Implements “Non-Energetic” Method of Signal Reception
P. 7–15.
Fig. 9. Tabl. 1. Refs.: 10 titles.
In this paper, the impulse radio UWB receiver sensitivity is estimated. The receiver implements “non-energetic” method of signal reception which provides pulses selection with amplitude that exceeds the root mean square value of noise and interference rather than accumulation of received pulses energy. Selected pulses are used to start a generator of pulses with a longer duration and higher amplitude. The latter are processed by a passive match filter. Calculations show that such receiver effectively receives the pulse signals and has a disadvantage of only 2 dB compared with the optimal coherent and 1 dB with non-coherent method of signal reception.
Bezrodny M.K., Halan M.A.
The Energetic Efficiency of Heat Pump Ventilation System with Heat Recuperator and Exhausted Air Recirculation Application
P. 16–19.
Fig. 5. Refs.: 8 titles.
This paper demonstrates the results of operation analysis of the heat pump ventilation system with a heat recuperator and exhaust air recirculation. We also obtain the coefficient value of energy application for these systems. Finally, we make some conclusion on simultaneous application of the heat pump and the exhausted air recirculation used in the ventilation systems.
Kourilo I.A., Grudska V.P.
The Features of Voltage Control System with the Valve-Commutated Booster Transformer
P. 20–27.
Fig. 7. Refs.: 5 titles.
The article considers the operating conditions of the valve-commutated booster transformer, intended for high-speed stepless three-phase voltage control. We show that the uncoordinated supply of control pulses determining moments of valves operation can cause the appearance of unallowable voltage or current values.
Epik E.Ya., Suprun T.T.
Influence of Separation on Heat Transfer and Hydrodynamic of a Flat Working Surface of Heat Power Equipment
P. 28–35.
Fig. 5. Tabl. 1. Refs.: 16 titles.
The results of an experimental study of heat transfer, friction, velocity and temperature characteristics as well as turbulence structure on the flat surface are presented for relaxation zone after a separation at free stream turbulence Tue≈ 0,2 % in the range of velocities 5–10 m/s. The type of a separation (laminar, transitional or turbulent) is adjusted by velocity, shape of an inlet edge of the plate and length of an interceptor, installed in the end of test section of the wind tunnel. The dissimilarity of an internal structure of a hydrodynamic and thermal boundary layers and different rates of their recovery in relaxation zone were confirmed. The similarity equation was proposed for calculation of heat transfer intensification depending on turbulent viscosity.
Bidyuk P.I., Korshevnyuk L.O., Fefelov A.O., Litvinenko V.I.
Diagnosing Technical Objects Based on Artificial Immune Systems and Bayesian Networks
P. 36–45.
Fig. 6. Tabl. 2. Refs.: 10 titles.
A generalized information technology for building artificial immune systems for solving problems of technical diagnosis is proposed. The technology allows creating a mathematical description of the drift parameters and detecting anomalies in the operation of complex technical systems. The novel method and algorithm for detecting the location and type of failure of complex engineering system with Bayesian networks and information content criteria are created. The information technology for neural networks development based on the theory of immune systems is developed. Specifically, this technology is employed to meet the challenges of forecasting parameters drift of the technical object. A combined method and algorithm for detecting anomalies in controlled parameters of the diagnosis based on clonal selection are elaborated. Finally, the computational model experiments for the developed methods, algorithms and information technologies are conducted.
Glushak V.V., Novikov O.M.
The Method of Information Security System Design Using Deterministic Game “Defender–Attacker”
P. 46–53.
Fig. 2. Tabl. 1. Refs.: 14 titles.
This study describes the approach to solving the problem of creating a system of information protection with limited resources. The problem is solved using the game theory, notably a formal apparatus which allows taking into account the conflict relationships between an attacker and a defender. In terms of the game theory, the attacker’s reward is the damage inflicted on the victim, while the defender aims to minimize the risk and ensure the stable system operation. Solving the described problem, we obtain the optimal set of security measures that provides the maximum level of protection under the given constraints.
Golinko I.M., Kubrak A.I.
Determination of the Object Dynamic Characteristics Based on Control System Dynamics
P. 54–58.
Fig. 9. Refs.: 4 titles.
In this paper, we consider the algorithm for calculating the object dynamic characteristics in the automatic control system. Specifically, the algorithm allows obtaining numerically pulse and transitive characteristics of the process relying on the reaction of a control system on the task change. The algorithm of this problem solving can be numerically applied by employing the Duhamel integral. Moreover, we consider the sample of this algorithm program implementation when modeling transients in the control system.
Danylov V.Ya., Zinchenko A.Yu., Marchuk P.P.
Implementation of Information Technology for Identification of Dynamic Chaos and Pseudophase Reconstruction of Attractors of One-Dimensional Realization
P. 59–68.
Fig. 8. Tabl. 1. Refs.: 15 titles.
In this paper, we have offered the information technology of chaotic behavior identification of one-dimensional scalar realization of dynamic systems, scalar time series and the pseudophase reconstruction of their attractors. The applied methodology is based on 14 different modern methods. To optimize the computations, we have used the method of length estimation for partitioning phase trajectories. It led to modification of some methods that utilize correlation integrals. In addition, we have estimated the minimum distance between 2 points on the phase trajectory. By presenting the examples of stocks dynamics of a leading issuer according to the capital rating of the PFTS stock exchange, as well as of one-dimensional signal, obtained by calculating the dynamic system, we have conducted the research of chaotic dynamics, have discovered chaotic attractors and have also reconstructed their pseudophase space.
Dychka I.A., Golub V.I., Novosad M.V.
The Compression of the Alphanumeric Information in its Graphic Coding Representation
P. 69–76.
Fig. 5. Tabl. 2. Refs.: 6 titles.
We devise the compression method of alphanumeric information in its graphic coding representation. The method of data compression is based on converting data from one alphabet to another – from the alphabet of characters into alphabet of graphic coding symbols. The method provides the data compression on average by 20 % for digit data and by 12 % for text sequences. Furthermore, this method provides the storage of a large information content (over 1000 alphanumerical characters) in the form of graphical codes on a limited area of carrier.
Konovalyuk M.M.
Bayesian Analysis of Stochastic Volatility Model by OpenBUGS
P. 77–84.
Fig. 4. Tabl. 1. Refs.: 18 titles.
This article illustrates Bayesian analysis of stochastic volatility models of daily dollar/hrivna exchange rates from 10/24/2006 to 4/15/2011, using a package of applied programs OpenBUGS. In addition, we determine that the estimation is completely accurate with acceptable computational cost as well as characterized by convergence at a given time gap.
Legeza D.V.
Monitoring System of Sickness Rate of Acute Respiratory Diseases in Ukraine
P. 85–89.
Fig. 5. Refs.: 5 titles.
Based on the multivariate regression analysis, we construct a mathematical model which allows analyzing and predicting the ARD incidence on the territory of Ukraine. The obtained results indicate a high accuracy of our calculations and the model adequacy to real-life conditions.
Redko I.V., Snigur N.M.
An Algebraic Characteristic of the Graph Transformation Class on the Weighted Graphs Set
P. 90–94.
Refs.: 21 titles.
The paper under scrutiny considers a class of computable functions on a set of weighted graphs. Crucially, we find a generating set for the algebra of weighted graph functions and prove it is complete.
Radchenko S.G., Lapach S.M.
Generation of Quasi-Regular Quasi-Uniform Multifactor Experiment Designs (Algorithm RASTA8)
P. 95–99.
Diagram. Tabl. 3. Refs.: 8 titles.
We develop the RASTA8 algorithm for generating quasi-regular and quasi-uniform multifactor experiment designs by using ЛПt of uniformly distributed sequences. It allows obtaining the designs, not presented in catalogs as well as using them in further research. The conducted simulative experiment has shown that the obtained experiment designs are characterized by statistical criteria, rather close to the best possible criteria values.
Gavrish A.P., Roik T.A., Kirichok P.O., Vitsuk Yu.Yu., Khmiliarchuk O.I., Melnik O.O.
The Choice of Exploitation Parameters of Bearing Materials Based Made of Tool High-Speed Steel Based on the Friction Films Analysis
P. 100–107.
Fig. 6. Tabl. 1. Refs.: 7 titles.
This study presents the research results of secondary structure films of bearing materials made of tool high-speed steels Р6М5, Р6М5К5, Р6М5Ф3 abrasive wastes with the solid lubricant CaF2. They are formed on the contact surfaces at friction under hard exploitation conditions and influence functional properties of the friction unit. We also demonstrate the possibility of forecasting the necessary level of antifriction properties by creating films of the required depth and chemical composition as well as justify setting the materials exploitation parameters.
Gorbatenko Yu.P., Bondarev S.V., Zakora O.V.
the application of c involute gearing in the escalator Drive
P. 108–115.
Fig. 4. Refs.: 7 titles.
The subject-matter of our research is transport vehicles with a chain pulling device with an intermediate drive location. Specifically, the paper considers the engagement of the drive sprocket with a pull chain performing the function of cogging and discusses the features of cogging kinematics. We also identify overlapping factors and calculate gearing contact stresses.
Mikulionok I.O.
Definition of Mixing Time for the Closed Type Mixer with Oval Rotors
P. 116–120.
Fig. 2. Refs.: 10 titles.
This paper deals with the design procedure of mixing time of polymer or rubber mixtures taking into account its movement not only in circular, but also in an axial direction of a mixing chamber. The preliminary comparison of theoretical and experimental data shows the possibility of implementing the developed technique.
Рukhovyi I.І.
The Experimental Study of Detachable and Attachable Flow Limits of Liquid Film on the External Surface of Rotating Cone
P. 121–125.
Fig. 3. Refs.: 8 titles.
The paper studies detachable and attachable flow limits of liquid film on the external surface of the rotating cone with different angles at the foundation (from 30 to 55 degrees) in the range from 400 to 1700 rpm with the fluid flow up to 45,2 g/s. The film flow in the lift-off zone looks like radial convex streams, from which droplets are falling. The bulk of the liquid flame spray is formed. The angle cosine at the cone base influences the most the beginning of droplets falling from the film surface. Increasing the film thickness (liquid flow) and rising the speed can reduce the radius of droplets falling. Finally, we obtain the equations for calculating the initial radius of drops falling.
Kolobrodov V.G., Sirii Y.A.
Monochromatic Aberration of Kinoform Element
P. 126–129.
Fig. 6. Refs.: 5 titles.
Based on the aberration model of thin lens, we obtain the monochromatic aberrations of the paraxial kinoform element with a high efficiency in the first diffraction order. We consider the dependence of field aberrations from the aperture position. Moreover, we determine the conditions, under which the kinoform element is free from some aberrations. We also study the conditions of the variation range of each field aberration minimum in the spectral range of 8–12 microns for the element with specific design parameters.
Mikheenko L.A., Timofeev O.S.
Metrological Analysis of the Diffuse Transmitter Based on the Integrating Sphere with Light-Emitting Diodes
P. 130–137.
Fig. 6. Tabl. 5. Refs.: 18 titles.
This paper highlights the metrological analysis of the diffuse transmitter based on the integrating sphere with the cosine radiation sources. We propose novel simplified calibration methods of diffuse emitters.
Burtna I.A., Ruzhinska L.I., Lytvynenko D.V.
Mathematical Model of Pervaporation Separation of Binary Solutions
P. 138–142.
Fig. 2. Refs.: 5 titles.
The paper develops the mathematical model of pervaporation of the organic component through a non-porous polymer membrane in the round crossing. We also present a system of equations describing the process of pervaporation separation of binary solutions.
Gorobets S.V., Gorobets O.Yu., Dvoynenko O.K., Lebeda G.L.
The Effect of Magnetostatic Fields of Ferromagnetic Substrate on the Nickel Dendrites Electrodeposition
P. 143–147.
Fig. 3. Tabl. 2. Refs.: 11 titles.
The paper studies the effect of magnetic state of ferromagnetic substrate on the surface morphology of nickel electrodeposit obtained by the method of electrolysis. After conducting the statistical analysis, we can assume that the residual magnetization of substrate-wire significantly influences dimensioning characteristics of the formed dendrite structures at the absence of an external magnetic field at the Ni electrodeposition. The studied magnetic properties of substrate-wire are confirmed by Bitter powder figures.
Dontsova T.A., Neboga T.I.
The Interaction of Calcium Phosphate with Oxalate Acid
P. 148–151.
Fig. 4. Refs.: 14 titles.
This paper deals with the experimental research into the effectiveness of utilizing oxalic acid for decomposition of the phosphate component of phosphorites employing the trisubstituted calcium phosphate as a sample. Furthermore, the impact of such parameters as duration, temperature, the stoichiometric ratio of initial reagents is defined in the process of calcium phosphate dissolution. We determine that the calcium phosphate dissolution by the oxalate acid finishes in 30–45 minutes and the temperature at which the maximum expansion of calcium phosphate is 80 °C. The results obtained indicate the prospects of using organochemical leaching of phosphorites by the oxalic acid.
Pogrebova I.S., Iantsevitch C.V.
The Heat Resistance of Diffusion Chromosilicide Coatings Applied on a Carbon Stells
P. 152–155.
Fig. 3. Refs.: 7 titles.
The paper studies heat resistance and the mechanism of high-temperature oxidation of chromosilicide diffusion coatings applied on a surface of carbon steels by a gas method. We define the factors of influence on the process of high-temperature steels oxidation with the obtained coatings. The interrelation between the composition, the structure of diffusion layers and the speed of high-temperature oxidation is established. We show that the obtained coatings have a high heat resistance in an interval of temperatures between 623–1273 K. Finally, we propose the structure of a sealing mixture to decrease the speed of the high-temperature oxidation of diffusion coatings at a long isothermal endurance.
Yudina V.V., Sukhoverkhov V.D.
Neutral and Basic Dialkildithiophosphate Structure Investigation
P. 156–160.
Fig. 3. Tabl. 3. Refs.: 14 titles.
Neutral and basic zinc diisobutyldithiophophate (ZDDP) were synthesized and their structure was investigated. Diisobutyldithiophosphoric acid, neutral and basic ZDDP chemical composition was confirmed by elemental analysis. Obtained neutral and basic ZDDP differed by physical-chemical properties. IR-spectra comparison of neutral and basic ZDDP shows absence of absorption band which corresponds to hydroxyl group. XRD investigation neutral and basic ZDDP results in definite formulas and structures. Basic ZDDP is tetranuclear zinc complex with six organic ligands, and oxygen atom in centre of tetrahedron formed by four zinc atoms. Such structure give extensionality to basic ZDDP molecule and give an explanation to differ physical-chemical and antiwear properties. Thus by complex of proposed methods structure of such substances can be discovered for purposeful synthesis.