Автоматизация расчетной оценки долговечности бортовой радиоэлектронной аппаратуры авиационной техники
Automation estimate of durability onboard avionics aviation technology
The work is devoted to the mathematical models study for operational failure rate estimating of traveling wave tubes. The detailed analysis of the parameters taken into account in the considered models is carried out. The key factors that have the greatest impact on the reliability characteristics are highlighted. Based on the results of numerical evaluation of the traveling wave tubes operational failure rate according to the considered mathematical models, a significant difference in the obtained results is shown. Mathematical models of operational failure rate, taking into account the key factors (temperature and manufacturing technology) based on the analysis of the causes of failure of traveling wave tubes are recommended to use. However, the considered mathematical models, in aggregate, do not take into account the key factors. This leads to an unreliable assessment of the reliability characteristics at the design stages
Ensuring the target level of dependability measures in the design of unmanned automatic spacecraft (AS) electronic devices (ED) is an urgent task due to repeated cases of failure during the active lifetime. One of the important measures of ED dependability is their reliability, which is characterized by the failure rate. To calculate this measure in the early stages of the ED design, a methodology for assessing the “production quality factor” was developed, which is included in the failure rate model. A distinctive feature of the proposed methodology is the compliance of actions regulated not only by regulatory and technical documentation (RTD) for the ED creation, production and operation, but also by the quality management system (QMS). Implementation is to apply a structured approach to the formation of the questionnaire for subsequent expert evaluation of both external and internal audits. The methodology allows to timely identify the advantages and disadvantages of a specific action to ensure dependability specified in a certain RTD section of the technical documentation, including QMS. The use of the "production quality factor" obtained for the corresponding RTD taking into account the QMS could increase the authenticity of evaluating the ED dependability measures in the unmanned automatic spacecraft at the design stage. The methodology will enhance the numerical assessment efficiency of the ED dependability measures in the unmanned automatic spacecraft and save the implementing organizations from the additional tests procedure. The developed methodology is planned to be used at the space industry enterprises and in private non-state companies involved in the small satellites production.
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.
The modern level of technological advance allows the use of CAD systems at all the stages of the electronic communication modules development, which allows the designers to discard the time-consuming process of manufacturing and testing an experimental prototype. To organize the interaction of various CADs the design techniques are used. The report discusses the integrated cross-cutting design technique implemented using National Instruments software products. Their advantages and disadvantages are evaluated. The use of the NI LabView made it possible to implement a dynamic calculation of reliability indicators through the use of NI LabView Multisim Connectivity Toolkit, which confirmed the possibility of realization an integrated cross-cutting design technique.
Methodological issues abound when conducting cross-cultural research. In this manuscript we discuss three methodological issues present in many cross-cultural communication studies: lack of geographic diversity, reliability, and validity. To explore these issues the Personal Report of Communication Apprehension (PRCA-24) is assessed. The PRCA-24 serves as an exemplar of a US-designed and -validated measure frequently used outside the US without tests of validity or measurement invariance. In fact, since 1990 less than 10 studies have reported validity results, often citing fit issues. The PRCA-24 was administered to respondents from 11 countries and failed to yield acceptable fit statistics in all samples, showing poor construct validity. Implications for cross-cultural research are discussed, with particular emphasis on recommendations for increased cross-cultural methodological rigor.
It has been proved by the latest research on key performance indicators (KPIs) of transportation services that their successful implementation into practice is possible only if there is a thorough database of indicators and the methodology of their calculation. To reach these goals, it is necessary to classify the indicators within the framework of the system which includes the two levels: the basic (the first) and the specific (the second) KPI. This division allows to form the complex of models to calculate the basic indicators, which characterize performance (e.g. performance per hour), time parameters, expenses, reliability, etc. The article provides the analysis of papers on the methods of transportation efficiency rating in supply chains and the ways of their development to increase the efficiency of transportation; the new approach to obtain analytic dependencies to calculate KPI of transportation on the basis of the integral (factorial) method of economic analysis; the examples of calculations of some KPIs of transportation. The suggested KPI models can be used to create programs aimed at the digitalization of transportation operations in supply chains.
The self-perceived communication competence (SPCC) measure has been used in over 50 published studies since 2000. McCroskey and McCroskey (1988. Self-report as an approach to measuring communication competence. Communication Research Reports, 5, 108–113. doi: 10.1080/08824098809359810) developed the measure to be used within the US college/university classroom. Despite its intended use, the measure is frequently used outside of the US and outside of the college/university setting without tests of measurement invariance. In fact, only four studies have performed tests of internal consistency on the measure since 2000, and each has found poor fit. Therefore, the purpose of this study was to assess the utility of the measure outside of its intended population. The measure was utilized to survey respondents from 12 countries and failed to yield acceptable fit statistics in all samples, showing poor evidence of construct validity.
In this volume of “Lecture Notes in Networks and Systems”, we are pleased to present the proceedings of the 18th International Multidisciplinary Conference on Reliability and Statistics in Transportation and Communication (RelStat 2018), which took place in Riga in Latvia, from October 17 to October 20, 2018. This event belongs to a conference series started in 2001 and organized annually by the Transport and Telecommunication Institute (TTI) in Riga, Latvia. The mission of RelStat is to promote a more comprehensive approach supporting new ideas, theories, technologies, systems, tools, applications, as well as work in progress and activities on all theoretical and practical issues arising in transport, information, and communication technologies. Results of previous editions of RelStat were published by TTI Publishing House (RelStat 2001–2015) in the journal “Transport and Telecommunication” (ISSN 1407-6160), by Elsevier in the “Procedia Engineering” (RelStat 2016) and by Springer in “Lecture Notes in Networks and Systems” volume no. 36 (RelStat 2017). Design, implementation, operation, and maintenance of contemporary complex systems have brought many new challenges to “classic” reliability theory. We define complex systems as integrated unities of assets: technical, information, organization, economical, software, and human (users, administrators, and management) ones. Their complexity comes not only from their technical and organizational internal structure, which is built upon diverse hardware and software resources, but also from the complexity of information processes (data processing, monitoring, management, etc.) that must be executed in their specific environment.