Анализ факторов моделей для оценки эксплуатационной интенсивности отказов ламп бегущей волны
Traveling wave tubes (TWT) are widely used in power amplifiers for radio means of information transmission, including in space equipment. This is due to the fact that for them there are high requirements to ensure dependability, for example, due to the lack of possibility of maintenance for a long period of active existence. Hence the problem of warranty and reliable evaluation of individual dependability measure, in particular, reliability, because of uncertainty in choosing a mathematical model from the available set because of its variety. They include many factors that take into account the TWT parameters, including specific operating conditions (temperature, electrical parameters, vibration, etc.). The purpose of the work is to conduct an analytical review of mathematical models to improve the numerical evaluation reliability of the TWT operational failure rate due to the criterion of evaluation detail choice. The objects of study are travelling wave tubes. Mathematical models of TWT operational failure rate presented in actual scientific and technical and specialized sources became the subject of research. There is a detailed study of mathematical models for assessing the TWT operational failure rate in this paper. The analysis of parameters which are used at an operational failure rate estimation in each considered mathematical model is carried out. The most common causes of TWT failures are identified and generalized. The key factors that have the greatest impact on the TWT reliability are temperature and production technology. As a result, recommendations for the use of four mathematical models that will help to achieve the most reliable numerical estimate of the TWT operational failure rate are given. However, it is shown that in common they do not take into account all the key factors.
Negative pressure also means negative energy and, therefore, “holes”, antiparticles. Continuation across infinity to negative energies is accomplished by using a parastatistical correction to the Bose-Einstein distribution.
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.
DepCoS – RELCOMEX is an annual series of conferences organized by Wrocław University of Technology to promote a comprehensive approach to evaluation of system performability which is now commonly called dependability. In contrast to classic analyses which were concentrated on reliability of technical resources and structures built from them, dependability is based on multi-disciplinary approach to theory, technology, and maintenance of a system considered to be a multifaceted amalgamation of technical, information, organization, software and human (users, administrators, supervisors, etc.) resources. Diversity of processes being realized (data processing, system management, system monitoring, etc.), their concurrency and their reliance on in-system intelligence often severely impedes construction of strict mathematical models and calls for application of intelligent and soft computing methods.
This book presents the proceedings of the Ninth International Conference on Dependability and Complex Systems DepCoS-RELCOMEX, which took place in Brunów Palace, Poland, from 30th June to 4th July, 2014. The articles selected for this volume illustrate the variety of topics that must be included in system dependability analysis: tools, methodologies and standards for modelling, design and simulation of the systems, security and confidentiality in information processing, specific issues of heterogeneous, today often wireless, computer networks, or management of transportation networks.
Pressure sensors on the basis of thin-film tenzorezistorny nano – and microelectromechanical systems with the frequency output signal, steady to influence of temperatures are considered. Original schemes of frequency converters and topology of an arrangement of tenzoelement on a membrane of a sensitive element of the sensor are submitted.
This paper presents the urgent problem of improving the developed satellite telecommunication equipment reliability and quality. An analysis of the approaches used in the Russian Federation and the United States to assess the "production quality factor" is made, that directly affects the dependability and quality of the telecommunication equipment. Particular criteria are developed to evaluate the efficiency of the quality management system at the enterprises. Recommendations for the implementation of the developed criteria in the mathematical model for assessing the "production quality coefficient" for the failures category related to the systems management process factor are given.
Optimization of designing radio electronic equipment by criterions of temperature and reliability decrease time for creation the new radio electronic equipment, increase reliability of it and decrease expenditures during elementary stages of designing because designers have possibility to choose version of scheme and construction which ensure minimum temperatures of element base in conditions of exsploitation.
DepCos-RELCOMEX is an annual series of conferences organized by the Institute of Computer Engineering, Control and Robotics (CECR), Wroclaw University of Technology, since 2006.
Contemporary technical systems are integrated unities of technical, information, organization, software and human resources. Diversity of the processes being realized in the system, their concurrency and their reliance on in-system intelligence significantly impedes construction of strict mathematical models and calls for application of intelligent and soft computing methods.
The submissions included in this volume illustrate variety of problems that need to be explored in the dependability analysis: methodologies and practical tools for modelling, design and simulation of the systems, security and confidentiality in information processing, specific issues of heterogeneous, today often wireless, computer networks, or management of transportation networks.
A linear theory of the discrete interaction of electron beams and electromagnetic waves in slow-wave structures (SWS) is developed. The theory is based on the finite_difference equations of SWS excitation.The local coupling impedance entering these equations characterizes the field intensity excited by the electron beam in interaction gaps and has a finite value at SWS cutoff frequencies. The theory uniformly describes the electron–wave interaction in SWS passbands and stopbands without using equivalent circuits, a circumstance that allows considering the processes in the vicinity of cutoff frequencies and switching from the Cerenkov mechanism of interaction in a traveling wave tube to the klystron mechanism when passing to SWS stopbands. The features of the equations of the discrete electron–wave interaction in pseudoperiodic SWSs are analyzed.
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.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
The conference “2021 Systems of signals generating and processing in the field of on board communications” is organized with technical sponsorship of Russian (Moscow) IEEE Circuits and Systems (CAS04) Chapter IEEE Region 8, Russian Section Chapter, MTT/ED and Institute of Radio and Information Systems Association (IRIS), Vienna, Austria. The conference featured invited researchers, educators, managers, and graduate students, whose research activity, case studies or best practices, are shedding light on the theory or practice of engineering, include modern digital transportation systems design and technical operation, radio waves propagation, transmitting, receiving and processing signals in television and radio broadcasting devices, information technologies in transport. The main areas of the conference “Systems of signals generating and processing in the field of on board communications” include modern digital transportation systems design and technical operation, radio waves propagation, transmitting, receiving and processing signals in television and radio broadcasting devices, information technologies in transport. FIELD OF INTEREST: Components, Circuits, Devices and Systems; General Topics for Engineers; Signal Processing and Analysis. Reports presented at the conference are grouped in 6 sections: 1. Antennas and Radio Waves Propagation. 2. Navigation and Mathematical Algorithms of an Object Space Orientation. 3. Radiofrequency Applications. 4. Wire and Optical Communication and Control Systems. 5. Intelligent Transport Systems (ITS): Sub-section 1: Use of digital ITS infrastructure in telematic control systems on urban passenger transport Sub-section 2: Peculiarities of data exchange in cooperative ITS Sub-section 3: Theoretical Aspects of Artificial Intelligence Systems Development for Transportation Engineering Sub-section 4: Test methods of motor vehicles integrated into an intelligent transport environment 6. Digital signal processing in on-board radio systems
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.
This volume presents new results in the study and optimization of information transmission models in telecommunication networks using different approaches, mainly based on theiries of queueing systems and queueing networks .
The paper provides a number of proposed draft operational guidelines for technology measurement and includes a number of tentative technology definitions to be used for statistical purposes, principles for identification and classification of potentially growing technology areas, suggestions on the survey strategies and indicators. These are the key components of an internationally harmonized framework for collecting and interpreting technology data that would need to be further developed through a broader consultation process. A summary of definitions of technology already available in OECD manuals and the stocktaking results are provided in the Annex section.