Factor and regression modeling of the variable state devices in the system statistica

For designing the discrete variable state devices the methods of statistical modeling, in particular, the factor and multi-variable regression analysis have been offered to use. It was shown that the statistical methods which were not used earlier for solving the given problem, allow revealing physical laws of the elements operation in the device that promotes creating the structure optimal from the point of view of supporting minimum phase shift at controlling transfer constant. Reveal and substantial interpretation of the factor loadings influencing various researched characteristics allow changing traditional methodology and simplifying significantly optimization of correction and regulation parameters in phase-invariance devices. The computer system Statistica 6.0 was used for modeling in the pape

Modeling of attenuator structures on field effect transistors with minimal phase shift at attenuation regulation

Controlled absorbing attenuators on Schottky-gate FETs: T-circuit, T-shaped bridge circuit and transistor attenuator in the mode with controlled slope of voltage-current characteristic have been considered. Attenuator phase-frequency characteristics were modeled. The main difference of the circuits from the known ones consists in introduction of equalizers that conditions broadband feature and large attenuation range where minimum of the phase shift is achieved at regulation. As a result, the optimal parameters of adjusting circuits in attenuators are founded. It is shown that the least phase shift is provided in attenuators on transistor with controlled volt-ampere characteristic steepness. The comparative estimation of the considered base structures was given

Снижение вычислительной сложности алгоритма декодирования BCJR MAP в турбо-кодовых конструкциях

Рассматриваются вопросы, связанные с современными методами турбоко-дирования, перспективными для применения в цифровых системах связи. Представлены алгоритмы, которые позволяют снизить вычислительную сложность - log-MAP, linear-log-MAP и maxlog-MAP. Получено обобщенное выражение для вычисления логарифма отношения правдоподобий в процессе этих процедур декодирования. С помощью имитационного моделирования по методу Монте-Карло проведено исследование вероятностно-энергетических характеристик передачи информации в турбо-кодовых конструкциях

Automation of oil and gas exploration by active seismic electric method

The paper considers the issues of automation and improving the performance of the field work by the seismic electric method. It is shown that the measurement scheme used today is not optimal. It leads to a long-term deployment of the measuring installation, as well as the inability to use it in difficult geological and climatic conditions. The authors of the paper propose to use special magnetic antennas for recording the electromagnetic field, which eliminate all the drawbacks of grounded electric dipoles. It is shown that if simultaneously registering the various components of the electromagnetic field, it is possible to estimate the depth of the productive layers. The data of observations of seismic electrical effects in the gas-condensate field for various x, y, z components are given

Design Issues for MEMS-Based Pedestrian Inertial Navigation Systems

The paper describes design issues for MEMS-based pedestrian inertial navigation systems. By now the algorithms to estimate navigation parameters for strap-down inertial navigation systems on the basis of plural observations have been already well developed. At the same time mathematical and software processing of information in the case of pedestrian inertial navigation systems has its specificity, due to the peculiarities of their functioning and exploitation. Therefore, there is an urgent task to enhance existing fusion algorithms for use in pedestrian navigation systems. For this purpose the article analyzes the characteristics of the hardware composition and configuration of existing systems of this class. The paper shows advantages of various technical solutions. Relying on their main features it justifies a choice of the navigation system architecture and hardware composition enabling improvement of the estimation accuracy of user position as compared to the systems using only inertial sensors. The next point concerns the development of algorithms for complex processing of heterogeneous information. To increase an accuracy of the free running pedestrian inertial navigation system we propose an adaptive algorithm for joint processing of heterogeneous information based on the fusion of inertial info rmation with magnetometer measurements using EKF approach. Modeling of the algorithm was carried out using a specially developed functional prototype of pedestrian inertial navigation system, implemented as a hardware/software complex in Matlab environment. The functional prototype tests of the developed system demonstrated an improvement of the navigation parameters estimation compared to the systems based on inertial sensors only. It enables to draw a conclusion that the synthesized algorithm provides satisfactory accuracy for calculating the trajectory of motion even when using low-grade inertial MEMS sensors. The developed algorithm can be implemented in the individual navigation equipment designed to solve practical tasks requiring autonomous positioning

Participation of NO-synthase in Control of Nitric Oxide Level in Rat Hippocampus after Modelling of Ischaemic and Haemorrhagic Insult

Electron paramagnetic resonance (EPR) was used as a method for recording the content of the nitric oxide (NO) in hippocampal tissues of intact rats and rats after modelling of ischaemic and haemorrhagic stroke. Based on direct measurements of NO by EPR spectroscopy, it was shown that, within 5 hours after the onset of symptoms of ischaemic and haemorrhagic stroke, the formation of NO in the hippocampus was reduced by a factor of 2-3 and this reduction was maintained for a period of between 24 and 72 hours. The results show that a systemic character of a decrease in the intensity of NO production during the modelling of ischaemic events in the brain reflects the effects of central dysregulation of the functions at the level of the whole organism such that it is appropriate to consider implementing the correction of the vital systems of the body in a stroke. It has indicated that non-selective NO-synthase blocker L-NAME reduced the low level of NO production by a factor of 3 by its administration within 72 hours after post-ischaemic and haemorrhagic stroke. It was discovered however that L-NAME returns the level of NO production to baseline (control) by its administration within 5 hours after ischaemia