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No 6 (2016)
5-10 453
Abstract
The temperature distribution within the anodic alumina during the anodic process has been studied. The temperature increase can reach 300 °C at high lever of Joule heat. The parameters of the heat process such as the heat temperature coefficient, the specific temperature change and the number of thermal process similarity criteria have been determined. The simulation of the temperature distribution within the test system for the given parameters of anodizing has been performed.
11-17 368
Abstract
Ferromagnetic-ferroelectric composite materials on the base of Pb0.85Zr0.53Ti0.47O3-Sr2FeMoO6-δ (PZT-SFMO) compound have been prepared by a complex ceramic technology and the citrate-gel synthesis. It was determined that the dielectric permittivity of a sample with a content of PZT of 55 wt. % and SFMO of 45 wt. % increases with temperature due to the rise of electrical conductivity and an influence of the dielectric dispersion caused by the Maxwell-Wagner relaxation. The electrical conductivity of the sample with a content of PZT of 35 wt. % and a content of SFMO of 65 wt. % possesses a clearly expressed frequency dependence, at temperature lower than 600 K, whereas at higher temperatures the electrical conductivity almost does not depends on frequency in the range 20 Hz-1 MHz. This is concerned with a considerable decrease of critical frequency at higher temperatures. At frequencies higher than 100 kHz and temperature lower than 600 K, the electrical conductivity increases by a power law.
18-23 291
Abstract
The necessary theoretical knowledge for the creation and simulation of stochastic processes with desired properties of trajectories is shown. These properties include: passage of the trajectory through a set process milestones (areas), the formation of the dynamics of the process in view of a given stationary probability density, determination of process parameters on the basis of a predetermined length and duration of the trajectory.
24-29 1351
Abstract
By working out of a radar with the aperture synthesis of the aerial (RAS) of space basing there is a necessity of its debugging and verification at the land conditions. The most difficult verification task is requirement performance on resolution maintenance of RAS on an azimuth. It is caused by the given resolution provided in RAS at an orbit during stable moving in space with a speed about 7,6 km/s. The verification method of maintenance of the demanded linear resolution of RAS on an azimuth in land conditions with turned synthesis of aerial aperture is offered. It operates when RAS is unmoved and objects of resolution are placed at a moving ship.
30-34 274
Abstract
On the basis of the microscopic diffusion mechanism due to formation, migration, and dissolution of «impurity atom-intrinsic point defect» pairs, the investigation of phenomenon of impurity segregation in the vicinity of p-n -junction was carried out. The nonuniform distribution of point defects responsible for impurity diffusion has been taken into account.
35-39 395
Abstract
One of the main problems in the processing of tracks from different radars is the correct correlation of tracks (especially groups of tracks). The proposed algorithm is based on the principle of gravity by analogy with the physical phenomena of charged particles attraction. Modeling shows that probabilities of correct identification calculated according to this algorithm significantly higher than the values calculated by the known method.
40-46 333
Abstract
The method of probabilistic-algebraic simulation driven technological production processes with the potential danger elements, based on the conduct of proactive modeling using parameterized probabilistic-algebraic models is described, which is used for assessing the behavior of the object in the dynamics and thus improving the description adequacy of real processes of potential danger elements interaction during realization of the production cycle.
47-54 259
Abstract
Using features of Doppler frequency and two its derivatives in the filtration problem for radar survey have been considered. Comparative analysis of filtration parameters for different radar survey have been accomplished.
55-61 280
Abstract
The structure of a laboratory-modeling complex for researching the quality indicators of algorithms work for detection, measurement, support in optical-location systems is offered, using for this purpose as entrance influence a stream of video of the information of phon and target conditions from the multimedia screen.
62-66 1186
Abstract
The aim of this work is to find of the mechanism the determination of optimal temperature-time mode of crystallization during the whole process of β-BaB2O4 crystal growth by modified Czochralski method. The phase diagram of the BaB2O4-Na2O system in the temperature range of β-BaB2O4 crystal growing is taken as a basis. The regularities of the constant geometric size crystals growth depending on the crystal-forming oxides concentration, the drawing and cooling rates and the slope of liquidus were established. The described algorithm of calculation allows to choose an optimum time-temperature crystallization mode during the whole growth process.
67-72 2258
Abstract
The linear position control algorithms for multi-agent systems are described. The algorithms use a minimum of prior information and spread of these algorithms to the multidimensional case. The methods take into account the external impacts.
73-79 1381
Abstract
Results of the analysis of physical limits influence of the spherical wave model used for representation of an electromagnetic radiation of cellular phones on procedures adequacy of the probability estimation of its electromagnetic fields dynamic range near ground surface, are resulted. It is indicated, that taking into account these limitations practically does not affect on results of this estimation, but allows to simplify the procedure of a probability estimation of levels of predominating signals of cellular phones in places of its heavy use.
80-85 399
Abstract
An experimental justification of the content of electromagnetic shields constructions based on powdered perlite characterized by fire resistance property is made. The electromagnetic radiation reflection and transmission characteristics of such constructions before and after exposure to them by the open flame are researched.
86-93 284
Abstract
This paper considers a task of management data arrays in memory. As a part of a solution of the task authors present a way of implementing operations on management data arrays based on strategies of dynamic memory chunks allocation, which is done at the devices management level where knowledge-based system is executed. Tests results of the implementation of the proposed way are presented.
94-99 355
Abstract
The evaluation of the activity specifics of Belarus telecommunication companies is made. The realization principles of information protection systems auditing method in these companies is grounded with use of the evaluation results and the requirements of Belarus normative and legal documents in the spheres of information security and telecommunication.
100-106 2332
Abstract
Evaluation method of security assessment a speech signal in information leakage channel under high-level noise with significant Bandpass flatness by complex measuring signal with a large base in equal intelligibility bands is proposed. Using the mathematical approach a derivative of cross-correlation function between complex measuring signal with a large base at the inlet and outlet channel speech information leakage allows to determine the position of the axis points in which derivative is zero. After that its time delay and frequency shift at the output of leakage channel of speech information within а minimum mean square error are determined. Compensation with time delay high accuracy and frequency shift complex measuring signal with a large base at the output of information leakage channel allowed to significantly improving the accuracy and sensitivity of the assessment of protection a speech signal in information leakage channel.
107-112 265
Abstract
A method of content-dependent watermarking images without embedding digital watermark based on visual secret sharing scheme, which allows to encrypt the digital watermark as a noise like secret and public shadow images using binary content-dependent wavelet-pattern with visually significance features and code table and to reconstruct the digital watermark by means of performing a logical operation (AND, OR or XOR) on a secret and a public shadow images. The results of computer simulation are represented.
113-116 380
Abstract
Modeling results of output static characteristics of gallium arsenide transistors for extreme high frequency range are given. Direct ion-implanted gallium arsenide transistors with the special profile under the gate are analyzed. Many particle Monte Carlo method with the solving of the Poisson equation are used for simulation of the three dimension structure with submicron length of the gate. Investigation of the gallium arsenide device provided the new results which connected with the influence of the geometrical size of the structure and features of gate construction to the output static characteristics. New modeling method of contact regions in device is presented for gallium arsenide transistors.
117-120 247
Abstract
The method of determining the volume concentration of blood in contrast of the interference pattern in biological tissues is developed and described. The estimation of measurement uncertainty is given.


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ISSN 1729-7648 (Print)
ISSN 2708-0382 (Online)