Comparison of different coding schemes for 1-bit ADC

This paper devotes to comparison of different coding schemes (various constructions of Polar and LDPC codes, Product codes and BCH codes) for the case when information is transmitted over AWGN channel with quantization with lowest possible complexity and resolution: 1-bit. We examine performance (in terms of Frame-error-rate -- FER) for schemes mentioned above and give some reasoning for results we obtained. Also we give some recommendations for choosing coding schemes for a given code rate and code length

NOISE SHAPING IN SAR ADC

The successive approximation register (SAR) analog-to-digital converter (ADC) is currently the most popular type of ADC architecture, owing to its power efficiency. They are also used in multichannel systems, where power efficiency is of high importance because of the large number of simultaneously working channels. However, the SAR ADC architecture is not the most area efficient. In SAR ADCs, the binary weighted capacitive digital-to-analog converter (DAC) is used, which means that one additional bit of resolution costs double the increase of area. Oversampling and noise shaping are methods that allow an increase in resolution without an increase of area. In this paper we present the new SAR ADC architectures with a noise shaping. A first-order noise transfer function (NTF) with zero located nearly at one can be achieved. We propose two modifications of the architecture: with zero-only NTF and with the NTF with additional pole. The additional pole theoretically increases the efficiency of noise shaping to further 3 dB. The architectures were applied to the design of SAR ADCs in a 65 nm complementary metal-oxide semiconductor (CMOS) with OSR equal to 10. A 6-bit capacitive DAC was used. The proposed  architectures  provide nearly 4 additional bits in ENOB. The equalent input bandwitdth is equal to 200 kHz with the sampling rate equal to 4 MS/s

Experimental and Numerical Studies of Suppression of Forest Combustible Material Pyrolysis under Influence of Steam-Water Curtain

Forest fires inflict enormous damage to the environment and the economy of many countries around the world. This paper presents the results of experimental and numerical studies of the suppression of the pyrolysis reaction of forest combustible materials (birch leaves, spruce needles) under the influence of water vapor. The dependences of the characteristic times of suppression of the thermal decomposition and the complete decomposition of forest combustible material on the thickness of its layer were established. We used typical model of fire source with fixed height 0.04 m and varied diameter 0.02-0.06 m. The processes of suppressing the pyrolysis reaction of forest combustible materials were recorded using a high-speed video camera (recording frequency 6∙10{5} fps). Numerical studies were conducted using Ansys Fluent and Matlab. The obtained results are important for the development of technologies of extinguishing forest bottom fires

Development of an On-board Failure Diagnostics and Prognostics System for Solid Rocket Booster

We develop a case breach model for the on-board fault diagnostics and prognostics system for subscale solid-rocket boosters (SRBs). The model development was motivated by recent ground firing tests, in which a deviation of measured time-traces from the predicted time-series was observed. A modified model takes into account the nozzle ablation, including the effect of roughness of the nozzle surface, the geometry of the fault, and erosion and burning of the walls of the hole in the metal case. The derived low-dimensional performance model (LDPM) of the fault can reproduce the observed time-series data very well. To verify the performance of the LDPM we build a FLUENT model of the case breach fault and demonstrate a good agreement between theoretical predictions based on the analytical solution of the model equations and the results of the FLUENT simulations. We then incorporate the derived LDPM into an inferential Bayesian framework and verify performance of the Bayesian algorithm for the diagnostics and prognostics of the case breach fault. It is shown that the obtained LDPM allows one to track parameters of the SRB during the flight in real time, to diagnose case breach fault, and to predict its values in the future. The application of the method to fault diagnostics and prognostics (FD&P) of other SRB faults modes is discussed

Differentiation of physical education lessons by body mass index of schoolchildren

Background: Many methodological problems associated in a sports and fitness environment based on a differentiated approach remain beyond the interest of researchers and developers. The aim of the study was to differentiate physical education classes in school in terms of the individual body mass index of schoolchildren and experimentally prove the effectiveness of its implementation for the harmonious development of youth. Study participants: schoolchildren 15-17 years (n = 64). All the schoolchildren were divided into four groups using the method of body mass index (BMI). Interventions: Pedagogical research was carried out for 7 months at school. The study used tests "Ready for work and defense", BMI, body health indicator and cognitive rate. Main outcome measures. In schoolchildren from the groups (EG1 and EG2), differentiated by BMI for physical education classes, the results on physical qualities improved: endurance and dexterity (p < .05). In CG1, where there was no differentiation, during the experiment 3 schoolchildren with overweight added. Thanks to the experimental intervention in EG1, the schoolchildren kept their initial BMI normal. Separate education of schoolchildren has a positive effect on the cognitive abilities of schoolchildren: comparison of EG1 and CG1 (p < .01), comparison of EG2 and CG2 (p < .05). Findings. The study showed the effectiveness of the BMI in differentiating of youth into groups. If the differentiating physical education at school to indicators of BMI, it will significantly improve the performance of physical and cognitive abilities schoolchildren 15-17 years old and reduce obesity of youth

Individual system of self-monitoring of the daily motor activity of athletes

Background: The implementation of daily and weekly self-control of individual motor activity, consisting of various speed modes, is not a systematically studied issue. The aim of the study was to develop an individually-differentiated system of self-monitoring of daily physical activity of athletes to increase their motor regime and prove its effectiveness by increasing the level of physical development and health of participants in the experiment. Study participants: Thirty-two subjects from 18 to 25 years of age, engaged for 12 weeks at the Sports Club “Progress”(Glazov, Russia). Interventions: self-monitoring by the participants of this research on a ranking system for diverse types of physical exercises by their correlation to one ordinary step or author's motor unit. Main outcome measures: the author’s self-monitoring system contributes to lowering the body mass index of athletes and developing their endurance. However, its implementation is effective in increasing the level of physical health only among athletes, stably, systematically and without significant deviations in the level of weekly physical activity performing physical activity. The results of the study. the implementation of daily monitoring of motor activity of young people in various motor modes stimulates respondents to increase their motor daily, weekly and monthly activity. Findings. The author’s recommendations for the implementation of continuous self-monitoring will provide feedback to the user of the programme, increase motivation for setting individual goals of amateur athletes and strategies for their further achievement

Development of correction coefficients for cable cross-sections selection in polymeric cable channel

Relevance. The need to develop correction coefficients for selecting cable sections when laying in the polymeric cable channel in the Russian Federation. Currently, there are no recommendations fixed by the state standards for laying cable power lines in polymer pipes. Aim. To develop correction factors for laying cable power lines in the polymer cable channel. Objects. Cable transmission lines laid underground in polymer pipes. Methods. Numerical simulation of combined frequency-stationary method; determination of correction factors based on interpolation of model results; evaluation and analysis of comparison of cables in corrugated and smooth polymer pipes. Results. Calculations of the long-term current load for cables laid in the polymeric cable channel showed the effectiveness of this method of laying cable lines. The use of pipes with smooth walls makes it much more efficient to remove heat from cables into the environment (compared to a corrugated pipe), which allows you to increase the capacity of the same cable by about 25%, depending on the number of pipes laid nearby. Based on the results of the simulation of the thermal mode of corrugated and smooth polymer pipes, it can be concluded that corrugated pipe significantly complicates heat removal from the cable system to the environment (soil). This is due to the presence of air gaps in the ribbed structure of the corrugated pipe. The gaps filled with air act as a heat-insulating layer, unlike a smooth pipe in which this gap is absent. The developed coefficients will take into account the influence of the location of cables on their allowable current already at the design stage, which will reduce the cost of power transmission losses due to the wrong cable cross-section and high temperature

Risk Assessment and Scaling for the SLS LH2 ET

In this report the main physics processes in LH2 tank during prepress and rocket flight are studied. The goal of this investigation is to analyze possible hazards and to make risk assessment in proposed LH2 tank designs for SLS with 5 engines (the situation with 4 engines is less critical). For analysis we use the multinode model (MNM) developed by us and presented in a separate report and also 3D ANSYS simulations. We carry out simulation and theoretical analysis the physics processes such as (i) accumulation of bubbles in LH2 during replenish stage and their collapsing in the liquid during the prepress; (ii) condensation-evaporation at the liquid-vapor interface and tank wall, (iv) heating the liquid near the interface and wall due to condensation and environment heat, (v) injection of hot He during prepress and of hot GH2 during flight, (vi) mixing and cooling of the injected gases due to heat transfer between the gases, liquid and the tank wall. We analyze the effects of these physical processes on the thermo- and fluid gas dynamics in the ullage and on the stratification of temperature in the liquid and assess the associated hazards. A special emphasize is put on the scaling predictions for the larger SLS LH2 tank