Journal of the Russian Universities. Radioelectronics / Известия высших учебных заведений России. Радиоэлектроника
Not a member yet
541 research outputs found
Sort by
Метод обработки данных в комплексе прибрежных РЛС средней дальности
Get PDFThe article presents the basic principles of design and development of integrated middle range Coastal Surveillance System (CSS) used for water surface lookout. It provides solutions for such missions as command and control of maritime forces, border monitoring and control, prevention of illegal activities such as piracy, smuggling, illegal immigration, illegal fishing, supporting search and rescue (SAR) operations, and creates a common situation awareness picture of the Naval Theatre. The system structure diagram is designed to solve computational overload problem when processing large volume of data received from radar stations. The measurement-level fusion algorithm is developed based on the JPDA framework, in which radar data received from a single or group of radars and AIS data is aggregated in a processing center. The servers and workstations make use of local area network (LAN), using standard Gigabit Ethernet technologies for local network communications. Acquisition, analysis, storage and distribution of target data is executed in servers, then the data is sent to automated operator stations (console), where functional operations for managing, identifying and displaying of target on digital situational map are performed
ЭМИССИОННЫЕ ПРОЦЕССЫ ВЗАИМОДЕЙСТВИЯ КВАНТОВОЙ ЯМЫ С ДОНОРНЫМ ДЕЛЬТА-СЛОЕМ В pHEMT-ГЕТЕРОСТРУКТУРАХ
Get PDFThe paper provides experimental and theoretical study of pHEMT heterostructures with quantum well (QW) AlGaAs/InGaAs/GaAs and delta-doped layer used as active layers for fabrication of 4-18 GHz transistors. As the experimental techniques, the electrochemical capacitance-voltage (ECV) profiling and other methods of admittance spectroscopy are applied. Modernization of commercial ECV-profiling setup allows observing for the first time the concentration peak from a near-surface delta-layer of pHEMT heterostructures together with the enrichment peak from the quantum well. In order to optimize the etching speed the crater bottom control is performed by means of AFM. The electrolyte-semiconductor contact capacitance is measured with Agilent RLC-meter. The main theoretical technique used in the research is numerical modeling of nanoheterostructure key electronic features by self-consistent solution of Schrödinger and Poisson equations. The potential line-up for the conduction band bottom is obtained, and the quantized energy levels are calculated. The complex analysis of series of samples is carried out in order to understand the influence of delta-layer position on the level depth and at the carrier concentration. The optimum distance between QW and delta-layer providing the most efficient charge carrier delivery to quantum well is found. The performed research is aimed at improvement of microwave electronic devices allowing increase of the gain coefficient and the transfer characteristic of SHF-transistors
ИССЛЕДОВАНИЕ ВЛИЯНИЯ ДЛИНЫ СИГНАЛА ЭЭГ НА ТОЧНОСТЬ КЛАССИФИКАЦИИ УРОВНЕЙ АНЕСТЕЗИИ
Get PDFThis paper considers one of the challenging tasks during surgical procedure, i.e. depth of anasthesia estimate. The purpose of this paper is to investigate the effect of the analyzed EEG signal fragment duration on the accuracy of anesthesia level estimate using the linear discriminant analysis algorithm and determining the EEG signal length, which yields acceptable accuracy of anesthesia level separation using these parameters.A new method for classifying EEG anesthesia levels is proposed. The possibility of classifying levels of anesthesia is demonstrated by means of sharing the EEG parameters under consideration (SE, BSR, SEF95, RBR). The method can be used in anesthesia monitors that are used to monitor the depth of anesthesia in order to select the appropriate dose of anesthetic drugs during operations, thus avoiding both cases of intraoperative arousal and excessively deep anesthesia
Функциональное диагностирование сетей из цифровых автоматов состояний
Get PDFThe problem of functional diagnosis of digital devices forming a network of state automata is considered. This task for the network components is supposed to be solved, and the corresponding diagnostic devices for them are provided. The possibility of their population transformation into the tools for the entire network diagnostics is shown. The result of the transformation with the restrictions on the number of components with errors is simplified in compare with the original population. A procedure is proposed allowing to find analytical expressions defining an auxiliary control and an error discriminator for the most probable case of error localization (all errors are concentrated in a certain component of the network). The first part of the article provides a solution of the functional diagnosis problem for the case when the parity functions of all components are scalar, and the class of detectable errors is given by unit multiplicity. Next, the result generalizes for the case of vector functions, where multiple errors can occur. The procedure minimizes the sought for functional diagnosis devices with respect to the order when preserving the initial detecting ability within any network component. The obtained results are illustrated by an example of construction of functional diagnosis equipment for ranging signal processing device in broadband short-range radio engineering navigation system
ИССЛЕДОВАНИЕ ШИРОКОПОЛОСНОЙ ГИДРОАКУСТИЧЕСКОЙ СИСТЕМЫ, СОДЕРЖАЩЕЙ ПРЕОБРАЗОВАТЕЛИ ВОЛНОВОДНОГО ТИПА
Get PDFThe results of experimental research of models of antennas hydroacoustic system (HAS), containing transducers of the waveguide type (TWT), which represent a coaxial set of identical water-filled piezocylinders, electrically excited by the principle of a traveling wave formation in the inner cavity of the TWT, are given. Possibilities of the TWT are analyzed when they are excited in accordance with the solution of the synthesis problem for the investigated HAS. The realization of such excitation is carried out by means of software-controlled multichannel blocks and allows providing a close to uniform amplitude-frequency characteristic of radiation and linear phase-frequency characteristic of radiation in a 3-octave frequency band. The possibility of radiation in this band of ultrashort pulses, tunable in frequency, as well as the formation of signals similar to the signals of cetaceans, is shown. The influence of the number of active piezocylinders of the TWT and the character of its electric excitation on the frequency and impulse response of the investigated HAS is considered. Directional properties of models of antennas HAS, including scanning and pulse operation modes, are considered. A comparative evaluation of the calculated and experimental data, as well as an evaluation of the efficiency of the TWT radiation, is given
ОЦЕНКА СТАТИСТИЧЕСКИХ ХАРАКТЕРИСТИК МИОГРАФИЧЕСКОЙ ПОМЕХИ ПРИ МНОГОКАНАЛЬНОЙ РЕГИСТРАЦИИ ЭЛЕКТРОКАРДИОСИГНАЛА
Get PDFElectromyographic noise is one of the most common noises in electrocardiogram. In case of several electrocardiogram leads, electromyographic noise affects each lead to different extent. It can be taken into account when developing algorithms for multilead electrocardiogram record processing. However, in the existing literature, there is no information about the relationship of electromyographic noise in various ECG leads and their joint probability distribution. The purpose of this paper is to study statistical characteristics of electromyographic noise in ECG signal, from which the electromyographic noise is extracted. The paper proposes a method for extracting electromyographic noise from electrocardiogram signal, based on a polynomial approximation of electrocardiogram signal fragments in sliding window with overlapping fragment subsequent weight averaging. Using this method, fragments of electromyographic noise are extracted from multichannel electrocardiogram records. Based on the obtained data, a joint probability distribution function of electromyographic noise in two adjacent leads is selected, and the correlation relationships between the electromyographic noise in various ECG leads are investigated. The results show that the joint probability distribution function of electromyographic noise in two adjacent leads in the first approximation can be described using bivariate normal distribution. In addition, between the samples of electromyographic noise from two adjacent leads quite strong correlation relationships can be observed
Оптимальная длительность интервала наблюдения нестационарного потока отказов радиоэлектронных средств
Get PDFThe method for determining the optimal duration of monitoring interval of non-stationary Poisson failure rate of radio-electronic equipment (REE) for a wide range of stationary processes, modulating it by intensity. To know the optimal du-ration of monitoring interval, taking into account the flow double stochasticity is necessary to calculate and predict REE reliability factor, operating in near-Earth space as a part of artificial Earth satellites (AES). In the course of calculation REE is exposed to ionizing radiation of unsteady flows and electrostatic charges, leading to short duration or irreversible failures. Based on the known linear model of double stochastic point process a detailed mathematical analysis is made for the first time ever and analytical expressions were obtained for the optimal monitoring time interval with respect to minimum combined standard uncertainty. Since the true nature of unsteadiness is unknown, analysis is carried out for Gaussian and Gauss-Markov modulating processes, covering a wide range of random processes. The analysis results confirm practical similarity of optimal monitoring time interval values for a wide range of modulating processes
ВЫБОР РАЦИОНАЛЬНОЙ ПРОЦЕДУРЫ ТРАССИРОВКИ ПО КОНСТРУКТИВНОМУ КРИТЕРИЮ
Get PDFThe analysis of autorouter efficiency in the known CAD systems under structural and technological constraints is carried out. The revealed significant constraints are related to the thermal strength of the wires and possible mutual influence through the electromagnetic field. When manually designing the designer guided by his own experience, can ignore these and other constraints. Unlike a person, the autorouter strictly fulfills all the specified constraints, which, given the topology of the printed circuit board, does not allow tracing to complete. On the other hand, giving greater freedom to the autorouter often makes it impossible to meet the production requirements on permissible parameters of the topological pat-tern, which is the width of the conductors and the gaps between them. The problem of tracing printed circuit boards, including multilayer ones, has become much more complicated with the introduction of integrated circuits in TSOP, MOFP and BGA type enclosures packages with fine-pitch pins, a number of which can reach several hundred. The article investigates the possibility of maximizing printed circuit board topological space with these and other types of enclosures. The necessity of introducing a buffer zone around the component to improve the routing efficiency is explained. It is shown, however, that the avail-ability of a buffer zone does not eliminate the appearance of vias in it, the number of which depends on the routing type. On the basis of the proposed criterion for the autorouter performance, i.e. the ratio of the total wire length to the number of vias, the efficiency of using the topological space of a printed circuit board by three autorouters is analyzed.The presented experimental results of competing routing systems TopoR and Specctra confirmed the possibility to enlarge the pattern area of the printed circuit board for its further use