# Electronics, radio engineering and telecommunications

# Comparative Analysis of Average Risk Using the Recommended Limit Concentration of Gases Dissolved in Oil for Detecting Defects in Transformers 110 kV

The comparative analysis of values of average risk, which are accompanied by use of boundary values of concentration of the gases dissolved in oil recommended by known techniques, is presented in this article. For the solution of the given problem, expression for calculation of average risk taking into account laws of distributions of concentration of gases for defectless states and defective states, in conditions, when diagnostics is made on a complex of diagnostic parameters is offered.

# The Image Restoration Algorithms by Conventional Deconvolution

The modified conventional deconvolution method using discrete orthogonal transformations is proposed. The algorithms for method realization in Hadamard transformation field and in RTF basis are considered. RTF transformation is different from Fourier transformation and is the “calque” of difference methods. The main problem of algorithm realization – forming image degradation inverse matrix by symbolic method of any order of matrix forming – is solved. These algorithms for conventional deconvolution method significantly allow simplifying the computations independently of matrix order.

# Visualization of Surface Conduc¬tivity Distribution by Conductivity Zones Method

The usage of modification method for direct EIT problem solving is substantiated. The voltages on phantom contour with known current approximation of surface conductivity distribution are calculated. The classical algorithm with Newton–Raphson method for inverse EIT problem solving is shown. That is “refinement” of surface conductivities by results of analysis. The conductivity zones method to reduce the order and time of calculations is described (transition from solution of the equation with 1000 order to 16 times solving the equations with 14 order). The regularization method by A.N.

# Comprehensive Analysis of the Effective Rate in Adaptive Packet Radio Networks

The aim of the study is to evaluate the effectiveness of joint work of physical and link layer packet radio networks with adaptive control of length of data packets in a competitive access to the radio channel. To do this, an analytical model in the form of two equations, the first of which determines the probability of successful transmission at the physical and data link layer, as a function of the intensity of the errors in the channel and protocol redundancy package format.

# Studies into the Surface Processes of Heat Transfer of Biological Objects by Thermographic Method

In this paper, we elaborate the methods of determining the efficient heat parameters of biological objects. We study heat conduction and capacity on the surface layer of the skin cover by infrared thermography. This research is done under the standard conditions as well as under artificial restriction of blood supply aimed at determining the surface malperfusion as a factor of the pathological states

# The Features of Regularization Method for Solving the Electrical Impedance Tomography Inverse Problem by Zones Conductivities Method

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.

# Convergence of the Fixed and Mobile Informational-Telecommunicational Platforms and Networks

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.

# Eigen Waves of Cross-Waveguide

The purpose of the article is to obtain the algorithms for calculating the characteristics of its own waves in the cross waveguide cross and demonstrate their abilities. We solve the boundary value problem by the mode matching method. By employing the moment method functional equations arising from the boundary conditions are reduced to systems of homogeneous linear equations (SLE), whose order is equal to where M and N are number of terms in schedules of the fields in subfields specified below.

# Application of Nonreciprocal Electric Circuits with Passive Components

This paper describes the method of recording nonreciprocal passive multipoles containing gyrotropic medium with analysis of linear lumped electric circuits. Nonreciprocal passive devices are designed for meter and decameter wave ranges on the basis of nonreciprocal effects of helicon waves propagation in magnetized solid-state plasma. The base element for nonreciprocal passive devices is nonreciprocal transformer containing a helicon resonator.

# Simulation of Ionization and Emission Processes in the High-Voltage Electron-ion System with Cold Cathode and Pulse Ion Generator

This paper develops the mathematical model of high-voltage low pressure electron-ion system with a cold cathode and a pulse plasma ion generator disposed behind an anode. The model is based on kinetic equations describing time dynamics of ionization processes in the plane electrode gap with participation of electrons, ions and neutral species after ion charge exchange, as well as electrode emission processes, including reflection of atoms from cathode and electrons from anode.