Approach to Real-Time Communications in Wi-Fi Networks
The development of wireless communication technologies attracts increased interest to scenarios that impose severe restrictions on data transmission reliability and latency. Such scenarios include real-time applications, such as industrial automation, remote control, video streaming, and virtual reality. It is very difficult to satisfy the requirements imposed on the quality of service with the currently widespread communication technologies. Specifically, it is currently impossible to guarantee a low delay in Wi-Fi networks due to some peculiarities of the applied channel access methods. In this work, we study an approach that provides a low latency and high reliability of communications in Wi-Fi networks on the basis of an additional radio air interface. This approach is studied using the mathematical model of a heterogeneous network, which consists of devices that generate prioritized and non-prioritized data packets. The results of studies show that this approach provides the ability to satisfy the requirements of real-time applications, when certain restrictions on the intensity of prioritized traffic are met. In this case, a decrease in the throughput for non-prioritized traffic is insignificant.
The considered model of the failure rate of CMOS VHSIC design proposed in the article Piskun G.A., Alekseev V.F., "Improvement of mathematical models calculating of CMOS VLSIC taking into account features of impact of electrostatic discharge", published in the first issue of the journal "Technologies of electromagnetic compatibility" for the year 2016. It is shown that the authors claim that this model "...will more accurately assess the reliability of CMOS VHSIC design" is fundamentally flawed and its application will inevitably lead to inadequate results. Alternatively, the proposed model of the failure rate of CMOS VHSIC design, which also allows to take into account the views of ESD, but based on the use of resistance characteristics of CMOS VHSIC to the effects of ESD.
The article considers the questions assessing the reliability of mechanical components used in the electronic equipment in the early stages of design. The calculations of failure rates springs shock absorbers according to various methods. It is shown that the use of models failure rates of mechanical elements, taking into account the peculiarities of their structural and technological performance, not only allows us to solve the problem of calculating, but also to ensure the required level of reliability and mechanical components, and containing electronic equipment.
The article is devoted to the problem of selfdisclosure of a personality as implicit readiness to active self-fulfillment. The author examines positive and negative consequences of self-disclosure in communication and studies temporal boundaries, time and relevance of self-disclosure of a person in dyadic, interpersonal and inter-group relationship.
The monograph presents results by professor Dr. A. Shalumov’s Research School of Modeling, Information Technology and Automated Systems (Russia). The program, ASONIKA, developed by the school is reviewed here regarding reliability and quality of devices for simulation of electronics and chips during harmonic and random vibration, single and multiple impacts, linear acceleration and acoustic noise, and steady-state and transient thermal effects. Calculations are done for thermal stress during changes in temperature and power in time. Calculations are done for number of cycles to fatigue failure under mechanical loads as well as under cyclic thermal effects. Simulation results for reliability analysis are taken into account. Models, software interface, and simulation examples are presented.
For engineers and scientists involved in design automation of electronics.
This book constitutes the refereed proceedings of the 5th International Workshop on Multiple Access Communications, MACOM 2012, held in Maynooth, Ireland, in November 2012. The 13 full papers and 5 demo and poster papers presented were carefully reviewed and selected from various submissions. The papers are organized in topical sections on network coding, handling interference and localization techniques at PHY/MAC layers, wireless access networks, and medium access control.
Mathematical models of failure rate of refusals the elements applied in calculations of reliability of the onboard electronic equipment are considered. Possibility of application the models given in foreign standards, for forecasting of reliability of completing elements is shown.
The basic influencing the factor defining its reliability are temperature influences at which speed of chemical reaction of materials a part REE increases. It is represented the equation which has been received by the Swedish chemist Svante Arreniusom from thermodynamic reasons
The monograph contents totaled the many years results of Scientific school «The Automated System for Ensuring of Reliability and Quality of Equipment - ASONIKA» National research University «Higher school of Economics» (scientific supervisor of the Scientific school - academician of RANS, doctor of technical sciences, professor YU. Kofanov) and long-term cooperation with the scientists of Kiev Institute of mathematical machines and systems problems of the Ukrainian National Sciences Academy (Deputy Director on science, doctor of technical sciences V.P. Strelnikov). The final structure of the monograph had been formed in the discussion of modern problems of reliability aerospace electronic equipment at the XVII International scientific-technical conference «Systemic problems of reliability, quality, mathematical modelling, information and infocommunication technologies in innovation projects». This conference was dedicated to the 20th anniversary of the HSE. The book outlines the basics of probability-physical approach to the study and the assessment of the reliability of onboard aerospace equipment. Presents the methods of estimation of reliability parameters of electronic components, as according to reference data and test or operating results in the presence or absence of failures. Developed the methods of calculation of reliability parameters of mechanical elements of aerospace equipment as well as research methods reliability of redundant and non-redundant, non-renewable and renewable systems on the basis of adequate two-parameter distributions of diffusion. Established the theory of planning reliability test with lightweight, durable, including accelerated testing with new methods of processing the testing results and reliability assessment. We propose new methods of evaluation and prediction of the aerospace equipment reliability to measure the determining parameters. Developed methodology of the statistical characteristics evaluation of the degradation process for the study of single samples of aerospace equipment using information about its representative minobject (minibranch, mineralizatsiya). All problems of reliability, which is solved in this book (mathematical modeling, calculation and experimental evaluation of the reliability of systems) result in the identification of the time until failure (or to failure) distribution. It is proved that when assessing the reliability of onboard aerospace equipment, most accurate results diffusion DN-distribution. On the basis of the law of distribution can be carried out the evaluation of all the necessary parameters of aerospace equipment reliability (mathematical expectations developments, gamma-interest developments, the probability of non-failure operating time for the specified time, the residual resource and others). The book provides a large number of examples and problems, proving the effectiveness and efficiency of the proposed methods. Material monograph mostly taught HSE in the various courses of lectures. The monograph is intended for a wide circle of specialists working in the field design, testing and operation of onboard aerospace equipment, as well as students and graduate students of the HSE in the execution of their coursework, independent scientific research, and the preparation of graduation theses and dissertations.
Maintenance of reliability of radio-electronic equipment taking into account thermal modes for various classes of electroradioproducts (ERP) within the limits of system ASONIKA is considered.
A model for organizing cargo transportation between two node stations connected by a railway line which contains a certain number of intermediate stations is considered. The movement of cargo is in one direction. Such a situation may occur, for example, if one of the node stations is located in a region which produce raw material for manufacturing industry located in another region, and there is another node station. The organization of freight traﬃc is performed by means of a number of technologies. These technologies determine the rules for taking on cargo at the initial node station, the rules of interaction between neighboring stations, as well as the rule of distribution of cargo to the ﬁnal node stations. The process of cargo transportation is followed by the set rule of control. For such a model, one must determine possible modes of cargo transportation and describe their properties. This model is described by a ﬁnite-dimensional system of diﬀerential equations with nonlocal linear restrictions. The class of the solution satisfying nonlocal linear restrictions is extremely narrow. It results in the need for the “correct” extension of solutions of a system of diﬀerential equations to a class of quasi-solutions having the distinctive feature of gaps in a countable number of points. It was possible numerically using the Runge–Kutta method of the fourth order to build these quasi-solutions and determine their rate of growth. Let us note that in the technical plan the main complexity consisted in obtaining quasi-solutions satisfying the nonlocal linear restrictions. Furthermore, we investigated the dependence of quasi-solutions and, in particular, sizes of gaps (jumps) of solutions on a number of parameters of the model characterizing a rule of control, technologies for transportation of cargo and intensity of giving of cargo on a node station.
Generalized error-locating codes are discussed. An algorithm for calculation of the upper bound of the probability of erroneous decoding for known code parameters and the input error probability is given. Based on this algorithm, an algorithm for selection of the code parameters for a specified design and input and output error probabilities is constructed. The lower bound of the probability of erroneous decoding is given. Examples of the dependence of the probability of erroneous decoding on the input error probability are given and the behavior of the obtained curves is explained.
Event logs collected by modern information and technical systems usually contain enough data for automated process models discovery. A variety of algorithms was developed for process models discovery, conformance checking, log to model alignment, comparison of process models, etc., nevertheless a quick analysis of ad-hoc selected parts of a journal still have not get a full-fledged implementation. This paper describes an ROLAP-based method of multidimensional event logs storage for process mining. The result of the analysis of the journal is visualized as directed graph representing the union of all possible event sequences, ranked by their occurrence probability. Our implementation allows the analyst to discover process models for sublogs defined by ad-hoc selection of criteria and value of occurrence probability
The Handbook of CO₂ in Power Systems' objective is to include the state-of-the-art developments that occurred in power systems taking CO₂ emission into account. The book includes power systems operation modeling with CO₂ emissions considerations, CO₂ market mechanism modeling, CO₂ regulation policy modeling, carbon price forecasting, and carbon capture modeling. For each of the subjects, at least one article authored by a world specialist on the specific domain is included.