R. V. Belyaev

Passive broadband acoustic thermometry

The 1D internal (core) temperature profiles for the model object (plasticine) and the human hand are reconstructed using the passive acoustothermometric broadband probing data. Thermal acoustic radiation is detected by a broadband (0.8–3.5 MHz) acoustic radiometer. The temperature distribution is reconstructed using a priori information corresponding to the experimental conditions. The temperature distribution for the heated model object is assumed to be monotonic. For the hand, we assume that the temperature distribution satisfies the heat-conduction equation taking into account the blood flow. The average error of reconstruction determined for plasticine from the results of independent temperature measurements is 0.6 K for a measuring time of 25 s. The reconstructed value of the core temperature of the hand (36°C) generally corresponds to physiological data. The obtained results make it possible to use passive broadband acoustic probing for measuring the core temperatures in medical procedures associated with heating of human organism tissues.

Coding and Processing of Graphic Information in Telecommunicational Networks

The method for the graphic information processing allowing coding the contour images by means of complex numbers uniquely defined by form of the image and solving problems of the recognition: identification of an object and determination of figure orientation on the plane was developed.

Complex chaotic discrete signals in telecommunications, radar, and navigation systems

Discrete chaotic signals with a high information capacity are developed and studied on the basis of nonlinear chaotic dynamic systems. The structural and fractal complexity of pseudorandom integer and binary sequences is analyzed. A model digital spread-spectrum radio channel is used to show experimentally that the chaotic algorithms developed can be applied efficiently in various radio facilities, such as telecommunications, radar, and navigation systems. A technique is developed for forming a reproducible irregular fractal structure involved in frequency-independent fractal antennas with a given fractal dimension. An integer chaotic algorithm with retardation is employed to generate a pseudorandom sequence.

DYNAMIC-CHAOS INFORMATION TECHNOLOGIES FOR DATA TRANSMISSION, STORAGE, AND PROTECTION

Information technologies based on dynamic chaos are considered. Their promising applications in data transmission, processing, storage, and protection are reviewed. Wideband data transmission channels that use complex signals with a large processing gain produced by dynamic chaotic systems are described. Finite-dimensional mathematical algorithms are proposed for calculation of chaotic signals by reconstructing nonlinear dynamics in dissipative systems with delay. It is shown that a digital data transmission system with spread spectrum and dynamic code escape exhibits high noise immunity and security, is electromagnetically compatible with other devices, and guarantees reliable and confidential data transmission in a complex electromagnetic environment. Schemes of data masking, protection, processing, and transmission are implemented in original chaotic algorithms.

Locking of self-oscillatory systems with random dynamics

Equations are proposed for describing a self-oscillatory system with a time delay and random dynamics. The interaction of two such systems with mutual diffusion-controlled coupling and the case of one-way coupling are analyzed. It is shown that in both cases, the locking is partial because difference random oscillations persist. Transient processes in random locking stabilization are considered

Investigation of features of sensing of video information in telecommunication systems

The study of features of sensing of video information from a monitor was carried out. The account of characteristics of ocular movements in the process of perception of video information in telecommunication systems allows developing of more effective information technologies, considering features of cognitive processes.

Analysis of a random self-oscillating system with a varying structure

The Rossler equations are transformed to the oscillatory form and are used for constructing a new mathematical model of a controllable system with a varying structure based on the randomizing feedback algorithm. Numerical methods are employed for analyzing randomization of oscillations with the help of self-switching in the case when only regular movements can take place without it. Apart from analysis of a single system with self-switching, randomization of oscillations in a complex system with a varying structure is considered on the basis of two models. It is found that partial synchronization of randomized oscillations of subsystems, which is associated with the existence of a common controlling feedback for these subsystems, takes place.

Coding and processing of graphic raster information in telecommunications technologies

A method of processing graphical information, allowing coding any contour images by using complex numbers explicitly determined by a form of image and solving problems of objectpsilas identification and recognition in the presence of noise was developed.

A method for digital processing of bitmap images

A method for processing of graphical information is proposed. The method makes it possible to code contour images with the use of complex numbers unambiguously defined by the image shape. Mapping of a noise bitmap image onto the complex plane is studied. The possibility of solving such recognition problems as object identification and determination of the orientation of a figure in a plane is demonstrated.

Spectrum spreading communication system on the basis of chaotic binary signals

The development of telecommunications systems using complex signals with large base is considered. The information transmission method by means of code division channel on the basis of chaotic codes ensemble was realized. The hardware realization of the modem using extension and inverse compression of the spectrum directly on carrying frequency of the signal is designed for microwave range. It is shown that digital wide-band communication system with spread spectrum and dynamic change of the chaotic codes have got a high noise immunity factor, secretiveness and provide the reliable transmission of the information in condition of the complex electromagnetic environment.