The possibility of using nonlinear effects in hydroacoustic systems with parametric radiation mode for profiling the bottom and bottom sediments attracts the attention of both domestic and foreign specialists. The use of parametric antennas in hydroacoustic equipment allows, due to their high directivity and low side field level, to increase the information content and accuracy in detecting and determining the coordinates of underwater objects, and to obtain additional features for recognition. The efficiency of using a parametric profiler for solving problems that require high resolution is justified. A block diagram of a parametric profiler for studying the layered structure is developed. The features of the signal generator and the amplification unit are considered. The characteristics of the radiating antenna were measured under laboratory conditions. It is shown that the directivity characteristic is constant in the operating frequency range and the acoustic power at the output makes it possible to solve the tasks of sounding up to 10 m into the ground. A record of the soil profile was obtained, confirming the operability of the system. In the future, the results will be used in full-scale conditions with the use of cepstral echo processing.
Keywords: profilograph, parametric antenna, kepstr, block diagram, signal generator, power amplifier, directional pattern, amplitude-frequency response, pump antenna, ground profile
The use of a separate receiving antenna at different frequencies in parametric acoustic systems is associated with the irreversibility of nonlinear processes underlying its principle of operation. The paper considers the results of experimental and theoretical studies to assess the influence of external elements on the amplitude-frequency response of a piezoceramic acoustic antenna. The structural scheme of the experimental setup is considered. It is shown that parallel connection of an external inductance to a piezoelectric element allows shifting the antiresonance frequency of an acoustic antenna, which leads to an increase in both the signal amplitude at the antenna output and an increase in the complex resistance module at the operating frequency.
Keywords: acoustic antenna, the sensitivity of the receiving antenna, the amplitude-frequency characteristic, the modulus of the complex resistance
In this paper proposed a statistical model of the optoacoustic transformation in the moving liquid medium using nanoparticles for a noninvasive blood analysis system. Since to increase the accuracy of measurements should take into account the probabilistic nature of the distribution of nanoscale objects as contrast agents in the blood stream in the human cardiovascular system. To determine the statistical characteristics of the component of the sound signal formed by a conglomerate of nanoscale objects using Monte Carlo simulation. Main static characteristics were calculated and the density distribution of the probability of the normalized amplitude of the sound signal was determined for a series of numerical experiments.
Keywords: optoacoustics, optoacoustic effect, flow cytometry, acoustic signal, carbon nanotubes, laser sound excitation, statistical analysis
Application for monitoring ice conditions devices based on nonlinear acoustics using parametric radiating antenna takes into consideration such characteristics of the formation of the acoustic field, as having both low-frequency difference frequency formed as a result of the nonlinear interaction of two close by the value of the pump waves, and, in fact, high-frequency radiation source pump waves Development of instruments for acoustic monitoring ice conditions require consideration of all possible real oceanographic situations in which they will operate. The article discusses the results of the development of a system for monitoring the panorama of ice conditions in the parametric mode sonar. The analysis of the formation and propagation of the probing signals into acoustic channel parametric meter ice thickness is formulated the principle of measuring the thickness of the reflection (scattering) of the acoustic signals from a locally stratified system with blurred boundaries. Mathematical modeling of the acoustic channel power meter ice thickness and "windows of transparency" on the basis of the calculation of the critical angles of incidence and refraction. The conclusion of the feasibility of using as reference signals of shear waves.
Keywords: ice monitoring acoustic antenna, the critical angle , the transparency window
This study analyses fractal characteristics of open-loop and closed-loop control mechanisms for different conditions of the sensor control. The stabilogram acquired using three types of the sensor control: open eyes (OE), closed eyes (CE) and visual artificial feedback (VAF). To determine the difference in control mechanisms for different condition of sensor control we have applied the method, offered by Collins J.J. and De Luca C.J. This method is based on the calculation of the Hurst exponent. We did not reveal significant differences (p>0,05) for control mechanisms between OE and CE parameters. However, there were significant differences for control mechanisms between VAF and OE parameters. We revealed that VAF reinforces open-loop and closed loop control mechanisms in anteroposterior directions, as well as VAF reinforces closed-loop control mechanisms in mediolateral directions. It may be important, in a rehabilitation setting, to identify which one of the two components of postural control (open loop or closed loop) needs more reinforcement in a particular patient, and consequently design an optimized device to improve postural balance.
Keywords: fractal analysis, Hurst exponent, open-loop, closed-loop, artificial feedback, analysis of stabilogram, postural control
The method of laser therapy is based on synchronization of phases of inflow (anacrotism) and outflow of blood (catacrotism) in the field of the pathological center with phases of a being narrowed and extending laser spot on a projection of this pathological center. It is supposed that being narrowed on a projection of the pathological center the spot of laser light stimulates blood inflow to the spot center, and the extending spot of a laser beam – activates blood outflow in the direction from the spot center to its periphery. The developed technique of the automated correction of hemodynamic frustration consists in pilot signal formation (in charge of the power and laser positioning) for the laser machine on the basis of a difference between a reference rheogram and a rheogram of the patient (a body site) in real time.The offered technique has to allow to use more efficiently methods of laser therapy at treatment of violations of a blood-groove. The technique is calculated on the basis of numerical experiment by means of methods of mathematical model operation.In the real experiment the question of synchronization of the reference and measured signal is considered solved though this task represents a subject of separate researches.The received pilot signal can be in real time transformed to the current signal operating positioning and laser power.The method gives the chance of an operating control of a condition of the patient and blood-groove diagnostics to, in time and after a session of laser therapy. Development provides possibility of adaptive individual correction and optimization of parameters of influence during a session and a course of treatment.
Keywords: laser, therapy, technique, rheogram, diagnostics, blood-groove, management, signal
The urgency and feasibility of application of biosensors with active biological layer for environmental studies was justified. A study of biosensors of various configurations to build a test system of environmental pollution control and determine the degree of aquatic toxicity was conducted. A simulation model of biosensor system was built. The selectivity of the biosensor was determined by theoretical experiments in which the analytical signal of the biosensor for biologically active layer without other biologically active substances was determined. The relationship between the type of transducer and biologically active substance was revealed. The software implementation of bisensor system was developed that reveals a number of pollutants and allows using not only different converters, but also different strains.
Keywords: biosensor, strain, quartz crystal, simulation model, environmental studies, pollutants, toxicity, sensitivity
A method of expanding the bandwidth and improve the performance of the differential voltage divider – attenuator (AT), which have parasitic capacitance on the outputs C01, C02. Wide range of transmission of the AT provided by introducing a compensation circuit C01, C02, which is achieving data quality indicators. Simulation results of desired are shown.
Keywords: a resistive voltage divider, differential attenuator, the parasitic сapacitance load, speed, upper frequency limit, analog-to-digital converters.
A hybrid reverberation algorithm is offered in this article. This algorithm is using both a convolution section in which a convolution with an inmpulse response of a real acoustic room is being implied and a mathematical reverb model. Also an algorithm for generating impulse responses of optional rooms is also offered in the following article. The algorithm efficiency calculation is specified in the article. Thia reverberation algorithm is a part of a bigger complez auralization algorithm where it is being used coherently with an HRTF-based algorithm in order to simulate a real acoustic environment
Keywords: artificial reverb, room simulation, convolution algorithm, impulse response convolution, impulse response synthesis, dynamic convolution, complex filtering
The mathematical features of construction information and measuring health systems (IMS). Because biological systems are complex, not always well-defined structure, for their correct description and implementation of metrological analysis requires its imposition. Accordingly, the presentation described bioinstrumentalnoe MIS. Within the theory of metrological synthesis formulated the concept of IMS core. With the use of the mathematical theory of categories and object-oriented modeling describes the basic relationships between the elements of the core IMS. The basic position with regards to the construction of MIS based on its structure. A scheme of the developed system of environmental monitoring of water environment on the basis of an integrated assessment of water quality. The main components of the system were presented. Feature of the developed system is the consideration of non-fixed sources of pollution, which was made possible thanks to the developed method of integral evaluation.
Keywords: Measuring health system, object-oriented modeling, method of integral evaluation
The features of circuit engineering and results of chip computer simulation which consists of 4-channel operational amplifier (op amp) and 2-channel electrometric voltage follower, designed for pre-processing of sensors signals in high-energy physics are considered.
The characteristic properties of designed op amp are the absence of current source in the input differential stage and the use of parallel high-frequency channel for increasing of the bandwidth and slew rate.
The results of experimental research that have confirmed the low sensitivity of the parameters of designed integrated circuits created on the field programmable gate array "FGPA-1.3" without the horizontal p-n-p transistors to the influence of gamma-irradiation and electrons with energy of 4 MeV are given.
Keywords: operational amplifier, field programmable gate array, voltage follower, sensor, sensing element, radiation resistance.
The requirements to be met by a data acquisition system in terms of each of the problems to be solved. Presented electric concept developed biopotential amplifier with a total gain of 2000. The theoretical model of the spectrum of RR intervals and changes depending on the running processes. The analysis revealed that the resulting spectrum satisfies the conditions considered in the theoretical model, and can be further analyzed with fractal characteristics.
Keywords: Instrumental amplifier, biopotential, fractal index
Regarding the structural evaluation of the instrumental error of bio MIS tool software package was developed that allows to take into account the error in the analysis of clinical diagnostic measurement in hematology research. It allows to analyze the results of hematological measurements with the measurement error and issue you with a message that characterizes getting results within normal or unreliability. Nanoparticles in biomedical analytical measurements are used as contrast agents, since, being immobilized specific proteins with adhesion to the diseased cells and bacteria. Register ultrasonic signal produced when the laser blood flow to the entered nanoparticles allows the detection and enumeration of diseased cells. The block diagram of analytical studies was designed to prove its basic metrological characteristics. Research is conducted in the centers for collective use of the Southern Federal University "Nanotechnology" and "Laser Technology", equipped with modern and unique nanotechnology research equipment.
Keywords: Bio MIS, nanoparticles, hematological measurements
Various non-invasive assessment of psycho-physiological and emotional state were analyzed: the fractal estimation of speech signals, the analysis of rhythmic EEG patterns and computer stabilometry. The results allowing prediction of the transition of the individual in a particular state, were obtained and objective criteria for determining the individual personality as a specialist were identified.
Keywords: Emotuonal speech, EEG pattern, attractor, suggestibility
Briefly discussed the theoretical model of the spectrum of RR intervals and its changes depending on the processes taking place. Made a device for measuring cardiointervalogramms (CIG). Obtained from the renting of data, of varying duration and frequency shall be recorded for further processing. The analysis revealed that the resulting spectrum satisfies the conditions considered in the theoretical model, and can be further analyzed with fractal characteristics. Such an analysis is of great importance in the diagnosis of the patient directly to the duration of the therapeutic procedure for the optimization of both time and intensity exerted influence.
Keywords: CIG; fractal series; the spectrum of RR intervals