ASSESSMENT OF THE RELIABILITY OF VACUUM PRECISION PIEZOELECTRIC RESONATORS ACCORDING TO THE RESULTS OF THE ACCUMULATION AND COMPILATION OF THEIR LIFE CYCLE

2018 ◽  
pp. 65-71 ◽  
Author(s):  
I. V. Arkhipova
Keyword(s):  
Life Cycle ◽  
Reliability Theory ◽  
Time To Failure ◽  
Bayesian Theorem ◽  
Piezoelectric Resonators ◽  
Reliability Indicators ◽  
Performance Requirements ◽  
Methodical Basis ◽  
New Ideas ◽  
Generalization Of Data

Within the framework of this article the question of reliability evaluation of resonators with strict performance requirements for resistance to external factors is considered. Due to the increase in requirements for these products in terms of gamma-percentile time to failure and gamma-percentile storageability time, there is a need to develop new ideas and methods of reliability theory. As a methodical basis for generalization of data of their life cycle the approach on the basis of Bayesian theorem is offered. Based on the results of generalization of the statistics of resonator tests for various types of climatic influences and reliability tests, as well as the results of their use in the electronic equipment have been identified their main reliability indicators.

THE ASSESSMENT OF THE RELIABILITY OF ELECTRONIC COMPONENTS OF FOREIGN PRODUCTION ON THE RESULTS OF TESTS OF SMALL SAMPLES

2018 ◽  
pp. 59-64 ◽  
Author(s):  
I. V. Arkhipova
Keyword(s):  
Electronic Component ◽  
Electronic Equipment ◽  
Small Samples ◽  
Time To Failure ◽  
Electronic Components ◽  
Bayesian Theorem ◽  
Foreign Production ◽  
Long Time ◽  
New Ideas ◽  
Standard Value

Within the framework of this article the question of reliability evaluation of electronic component base of foreign production, used as a part of electronic equipment of spacecrafts is considered. The reliability of electronic equipment of spacecrafts directly depends on the reliability of the electronic component base used as a component of it. This electronic component base should provide strict requirements for the active shelf life of the spacecrafts. To date, the requirements for gamma-percentile time to failure of electronic components used as a part of electronic equipment of spacecrafts, reaching 150,000 hours under standard value of у = 95%. Confirmation of such requirements is possible only in case of testing large samples for a long time, which entails considerable economic costs. This inevitably leads to the need to use and develop new ideas and methods of the theory of reliability. In this article, to confirm the reliability requirements for the electronic component base, it is proposed to generalize the estimated score and the data obtained from the results of accelerated tests for reliability, on the basis of the Bayesian theorem. In the result of the investigation was determined by the values of the failure rate of electronic components, as well as the possibility of increasing the value of probability of no failure operation у to a value of 99%, while maintaining the requirements of the gamma-percentile time to failure of electronic components base used as a part of electronic equipment of spacecrafts.

scholarly journals Determination of reliability of power supply of ship's responsible power receivers

2020 ◽  
pp. 22-26
Author(s):  
С.Е. Кузнецов ◽  
Н.А. Алексеев ◽  
А.А. Виноградов
Keyword(s):  
Power Systems ◽  
Power System ◽  
Power Supply ◽  
Electric Power System ◽  
Time To Failure ◽  
Parallel Operation ◽  
Diesel Generator ◽  
Operating Modes ◽  
Reliability Indicators ◽  
Supply Reliability

Изложена методика расчета показателей безотказности электроснабжения (вероятности безотказного электроснабжения и средней наработки до отказа) ответственных приемников морского судна, подключаемых к аварийному электрораспределительному щиту. Методика реализована применительно к судовой электроэнергетической системе с тремя источниками электроэнергии – двумя основными дизель-генераторными агрегатами, подключенными к главному электрораспределительному щиту, и одним аварийным дизель-генераторным агрегатом, подключенным к аварийному электрораспределительному щиту. Рассмотрены различные режимы работы судовой электроэнергетической системы: при работе до первого отказа одного основного дизель-генератора, при параллельной работе двух основных дизель-генераторов, при работе одного аварийного дизель-генератора; а также после обесточивания с учетом возможности последующего включения резервного или (и) аварийного дизель генератора. Методика, с соответствующими корректировками, может быть использована для расчета показателей безотказного электроснабжения в судовых электроэнергетических системах другой комплектации. Расчет показателей безотказности электроснабжения необходим при проектировании для обеспечения требуемого уровня надежности электроснабжения судовых приемников электроэнергии, а при эксплуатации – для предупреждения отказов и планирования технического обслуживания и ремонта элементов судовых электроэнергетических систем. The methodology for calculating the indicators of the reliability of power supply (the probability of failure-free power supply and the mean time to failure) of critical receivers of a sea vessel connected to the emergency electrical switchboard is presented. The technique is implemented in relation to a ship power system with three sources of electricity - two main diesel generator sets connected to the main electrical switchboard, and one emergency diesel generator set connected to an emergency electrical switchboard. Various operating modes of the ship's electric power system are considered: during operation until the first failure of one main diesel generator, during parallel operation of two main diesel generators, during operation of one emergency diesel generator; as well as after de-energizing, taking into account the possibility of subsequent switching on of the backup and / or emergency diesel generator. The technique, with appropriate adjustments, can be used to calculate indicators of reliable power supply in ship power systems of a different configuration. Calculation of power supply reliability indicators is necessary during design to ensure the required level of power supply reliability for ship power receivers, and during operation - to prevent failures and plan maintenance and repair of elements of ship power systems.

Exergy-Based Model of the Depletion of Mineral Resources

2010 ◽  
Vol 650 ◽  
pp. 1-8 ◽  
Author(s):  
Bo Xue Sun ◽  
Zuo Ren Nie ◽  
Yu Liu ◽  
Zhi Hong Wang ◽  
Xian Zheng Gong
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Mineral Resources ◽  
Assessment Method ◽  
Important Indicator ◽  
Related Research ◽  
Natural Minerals ◽  
New Ideas ◽  
Core Idea ◽  
Primary Problem

The primary problem of eco-materials is how to judge whether a material is environmentally friendly or not, and the method of life cycle assessment is usually used to evaluate it. The depletion of mineral resources is a very important indicator of LCA, but its characterization is still filled with dispute. At present, the most commonly used method is CML, which is put forward by Leiden University, and its core idea is that using the ratio of exploitation amount and reserves of mineral resources as the degree of scarcity. Although being accepted by most of the scholars at work on LCA, CML doesn’t grasp the essence of the depletion of mineral resources. Recently, a new assessment method, injecting new ideas to the conventional life cycle assessment, combines exergy with LCA is arising, which can be used to solve some specific problems of LCA especially the depletion of mineral resources. In this paper, two results of elements’ exergy calculated by Rivero and Szargut respectively are compared, and the exergy of some natural minerals, which can be used in LCA and other minerals-related research, is calculated based on the data of Chinese mineral resources.

The Influence of Engine Characteristics on Patrol Aircraft Life Cycle Cost Optimization

1982 ◽  
Author(s):  
A. J. Schuetz
Keyword(s):  
Life Cycle ◽  
Life Cycle Cost ◽  
High Speed ◽  
Cost Optimization ◽  
Life Cycle Costs ◽  
Design Constraints ◽  
Performance Requirements ◽  
Aircraft Performance ◽  
Antisubmarine Warfare ◽  
Flight Profile

A conceptual design study has been conducted for an all-new, land-based patrol aircraft for the U.S. Navy. The selected propulsion system was a conceptual high-speed turboprop. An antisubmarine warfare mission was chosen for the design flight profile. Probable peacetime utilization was postulated so that the engine duty cycle could be estimated. Aircraft designs were optimized for minimum takeoff gross weight (TOGW) and for minimum life cycle cost (LCC). It was shown that the aircraft performance requirements and design constraints bound the optimization process so tightly that the same point design is obtained for both TOGW and LCC criteria. The contribution of the engine costs to the overall life cycle costs was examined. The sensitivity of the aircraft optimization to the engine characteristics — specific fuel consumption (SFC), length, diameter, and cost — was analyzed. It was determined that SFC is the most significant engine characteristic.

scholarly journals Improvement of maintenance and repair system of internal combustion engines of automotive equipment

2021 ◽  
Vol 341 ◽  
pp. 00062
Author(s):  
Leonid Savin ◽  
Alexander Stetsenko ◽  
Vladimir Panyushkin
Keyword(s):  
Internal Combustion Engines ◽  
Road Transport ◽  
Operating Conditions ◽  
Time Interval ◽  
Repair System ◽  
Time To Failure ◽  
Operation Performance ◽  
Deterministic Models ◽  
Reliability Indicators ◽  
Time Drift

The paper analyzes the operating conditions of road transport affecting its reliability. It is concluded that it is necessary to develop scientifically based strategies flexible of AE maintenance based on predicting the failure moment by extrapolating the process of time drift of the informative parameters of the AE at the interval of its intended use. To solve this problem, we propose an approach based on the use of quasi-deterministic models of the time drift of the AE parameters, which allow to obtain analytical expressions for the main reliability indicators -density of the distribution time to failure and the probability of failure -free operation at a given time interval. On the basis of these indicators of reliability in operation, performance indicators have been formed allowing determining of the optimal maintenance frequency. In the final part of the article, the author proposes an algorithm and a methodology that allows organizing flexible strategies for AE maintenance, considering special conditions of its operation.

scholarly journals The role of Twitter in the life cycle of a scientific publication

2013 ◽  
Author(s):  
Emily S Darling ◽  
David Shiffman ◽  
Isabelle M. Côté ◽  
Joshua A Drew
Keyword(s):  
Social Media ◽  
Life Cycle ◽  
Social Impact ◽  
Scientific Publication ◽  
Decision Makers ◽  
New Ideas ◽  
Media Platform ◽  
Long Term Impact

Twitter is a micro-blogging social media platform for short messages that can have a long-term impact on how scientists create and publish ideas. We investigate the usefulness of twitter in the development and distribution of scientific knowledge. At the start of the 'life cycle' of a scientific publication, twitter provides a large virtual department of colleagues that can help to rapidly generate, share and refine new ideas. As ideas become manuscripts, twitter can be used as an informal arena for the pre-review of works in progress. Finally, tweeting published findings can communicate research to a broad audience of other researchers, decision makers, journalists and the general public that can amplify the scientific and social impact of publications. However, there are limitations, largely surrounding issues of intellectual property and ownership, inclusiveness and misrepresentations of science ‘sound bites’. Nevertheless, we believe twitter is a useful social media tool that can provide a valuable contribution to scientific publishing in the 21st century.

scholarly journals Analyzing the reliability of rolling stock units based on operational data

2021 ◽  
Vol 2021 (2) ◽  
pp. 251-260
Author(s):  
Aleksey E. TSAPLIN ◽  
◽  
Zh. O. Kuvondikov ◽  
Keyword(s):  
Failure Rate ◽  
Statistical Data ◽  
Practical Importance ◽  
Reliability Theory ◽  
Rolling Stock ◽  
Reliability Indicators ◽  
Equipment Reliability ◽  
Reliability Characteristics ◽  
Operational Data

Objective: To determine the most failure-prone rolling stock components and assemblies by processing statistical data obtained during operation using the classical reliability theory; to develop recommendations for maintaining the operational state of individual rolling stock components. Methods: Methods for calculating the quantitative reliability characteristics are used based on the rolling stock operational statistical data. Results: The 5-year operational data have been used to provide tabulated statistics on the failure rate of various rolling stock equipment. Reliability indicators have been calculated for various types of rolling stock equipment and the corresponding graphs have been plotted. Based on the calculations, the recommendations for the rolling stock maintenance have been developed. Practical importance: The calculations and the recommendations described determine the types of rolling stock equipment requiring more attention during maintenance

Development life cycle of the games through software engineering

2018 ◽  
Vol 1 (2) ◽  
pp. 14-23
Author(s):  
Mohammad AL_ Ansari
Keyword(s):  
Health Care ◽  
Life Cycle ◽  
Development Process ◽  
The Elderly ◽  
Game Development ◽  
Development Life Cycle ◽  
The World ◽  
New Ideas ◽  
Positive Character ◽  
Main Factor

The games in our time are the main factor in the world of entertainment and it does not depend on young children, but also enjoyed by the elderly and also have the ability to influence their behavior, which leads to new ideas and strategies that affect the positive character of the game .,, But also are used for serious purposes and can be launched on various areas such as health care and education. We will try to highlight software development in the game development process and will try to bridge the gap between the software developments processes used to develop the games.

METHOD FOR CALCULATING THE RELIABILITY OF QUARTZ RESONATORS

2020 ◽  
pp. 53-58
Author(s):  
M. I. Boychuk ◽  
L. A. Vasileva ◽  
S. A. Mikaeva
Keyword(s):  
Operating Time ◽  
Quartz Resonator ◽  
Test Time ◽  
Frequency Change ◽  
Piezoelectric Resonators ◽  
Reliability Indicators ◽  
Resonator Frequency ◽  
The Stability ◽  
Work Done ◽  
Minimum Operating

In the process of developing a thermocompensated quartz generator, it was necessary to calculate the reliability indicators of such an important element of the circuit as a quartz resonator for a failure-free period of 15 000 hours. The main parameter that can be used to evaluate the reliability of the quartz resonator is the stability of the nominal oscillation frequency. It is the stability of the nominal frequency of the resonator that formed the basis of the new developed technique. The method includes rules for constructing a probabilistic and statistical model of the dependence of the resonator frequency change on the test time. The article describes the work done on the accelerated evaluation of the reliability of piezoelectric resonators RK563 on the basis of probabilistic and statistical modeling of the behavior of the frequency from the test time. The method of mathematical modeling is based on the results of incomplete tests for a period of 30…50 % of the set value of the minimum operating time.

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