• Title/Summary/Keyword: information reliability

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Reliability Prediction using Telcordia SR-332 in Electric Home Appliance (Telcordia SR-332를 이용한 가전제품 신뢰도 예측)

  • Lee Duck-Kyu
    • Journal of Applied Reliability
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    • v.5 no.4
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    • pp.427-438
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    • 2005
  • This paper is concerned with the problem in predicting the reliability of an LCD product, Product reliability calculation methods classify accelerated life test (ALT) and using the reliability standard as MIL-HDBK-217F and Telcordia SR-332. The reliability standard can calculate estimating value more quickly than accelerated life test. The system MTBF was calculated in accordance of Telcordia SR-332 standard which includes directions of part electronic measurement, temperature rise and environmental test data. This research is intended to obtain the useful information for each electric design step to save time and cost.

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Computing Reliability Cluster-based in Wireless Distributed Sensor Networks (클러스터 기반의 무선 분산 센서 네트워크에서의 터미널 간 신뢰도 평가)

  • Lee, Jun-Hyuk;Oh, Young-Hwan
    • Journal of Applied Reliability
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    • v.6 no.4
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    • pp.297-306
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    • 2006
  • In this paper, We presented the algorithm for estimating a reliability between nodes in wireless distributed sensor networks (DSN). To estimate the reliability between nodes, we first modeled DSN as probability graph. Links of the graph are always reliable and the probability of node failure is independent. After all possible simple path which can be established between two nodes are examined, we perform sharp operation to remove repetition event between two nodes. Using probability for each variable of the minimized Boolean equation, we present the reliability formula.

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Collection and Analysis of Automotive Field Reliability Data (자동차 필드데이터 수집 및 신뢰도 분석)

  • Kwon, Young-Il
    • Journal of Applied Reliability
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    • v.8 no.1
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    • pp.1-13
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    • 2008
  • A methodology for collection and analysis of automotive field reliability data is presented. Automotive warranty system usually covers a pre-determined period of time and/or mileage accumulation. Therefore mileage information for the vehicles that have not experienced any failure or problems during the warranty period is not available. In this paper, a reliability analysis method using the estimated mileage distribution from an additional survey for vehicles that have not any record during the warranty period is proposed. Methods of reliability analysis using the warranty information collected under the EU and US warranty policies are also provided.

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Reliability Tests for BLDC Motors Used in Green-Cars (그린카 BLDC 모터의 신뢰성 시험)

  • Yoo, Ki-Hoon;Park, Boo-Hee;Kim, Ki-Tae;Kim, Gi-Young;Kim, Dal-Seok;Jang, Joong-Soon;Hahn, Chang-Su;Cho, Han-Sam
    • Journal of Applied Reliability
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    • v.11 no.1
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    • pp.97-110
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    • 2011
  • BLDC(Brushless Direct Current) motor is a powerful device to control the automotive electronic components used in green cars such as HEV/EVs(Hybrid Electric Vehicle and Electric Vehicle). This study is to propose reliability test items derived through pretesting, suitability analysis abd classification of previous BLDC motor tests. For environmental stress tests are determined by analysing environmental conditions and relevant failure mechanisms induced by climate loads, mechanical loads, chemical loads, etc. ATL and HALT are also considered for life testing and screening.

Mobile Resource Reliability-based Job Scheduling for Mobile Grid

  • Jang, Sung-Ho;Lee, Jong-Sik
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.1
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    • pp.83-104
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    • 2011
  • Mobile grid is a combination of grid computing and mobile computing to build grid systems in a wireless mobile environment. The development of network technology is assisting in realizing mobile grid. Mobile grid based on established grid infrastructures needs effective resource management and reliable job scheduling because mobile grid utilizes not only static grid resources but also dynamic grid resources with mobility. However, mobile devices are considered as unavailable resources in traditional grids. Mobile resources should be integrated into existing grid sites. Therefore, this paper presents a mobile grid middleware interconnecting existing grid infrastructures with mobile resources and a mobile service agent installed on the mobile resources. This paper also proposes a mobile resource reliability-based job scheduling model in order to overcome the unreliability of wireless mobile devices and guarantee stable and reliable job processing. In the proposed job scheduling model, the mobile service agent calculates the mobile resource reliability of each resource by using diverse reliability metrics and predicts it. The mobile grid middleware allocated jobs to mobile resources by predicted mobile resource reliability. We implemented a simulation model that simplifies various functions of the proposed job scheduling model by using the DEVS (Discrete Event System Specification) which is the formalism for modeling and analyzing a general system. We also conducted diverse experiments for performance evaluation. Experimental results demonstrate that the proposed model can assist in improving the performance of mobile grid in comparison with existing job scheduling models.

A New Agent Based Fault Tolerant IED System and Its Reliability Analysis (새로운 에이젼트 기반의 결함극복 IED시스템 및 신뢰성 분석)

  • Fan, Weizhong;Lee, Dong-Wook;Lee, Seun-Jae;Lim, Sung-Il;Han, Seung-Soo
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1371-1373
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    • 2005
  • Nowadays, Intelligent Electronic Devices(IED) are widely used in power system. In order to improve the selectivity, sensitivity, and reliability of the power system composed by IEDs, A new fault tolerant IED system based on agent technique is presented in this paper. in the presented system, different with existing IED systems, the redundancies are drawn out from IED devices, and compose a standby backup system. And those redundancies are not specified to a particular type of IEDs. By using the agent technique, redundancies can download agents to modify their functions to fit different types of IEDs. As a conclusion, the reliability of the presented system is estimated in this paper.

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Estimating the reliability and distribution of ratio in two independent variables with different distributions

  • Yun, Sang-Un;Lee, Chang-Soo
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.5
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    • pp.1017-1025
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    • 2012
  • We consider estimations for the reliability in two independent variables with Pareto and uniform or exponential distributions. And then we compare the mean squared errors of two reliability estimators for each case. We also observe the skewness of densities of the ratio for each case.

A Comparative Study on Nonparametric Reliability Estimation for Koziol-Green Model with Random Censorship

  • Cha, Young-Joon;Lee, Jae-Man
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.2
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    • pp.231-237
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    • 1997
  • The Koziol-Green(KG) model has become an important topic in industrial life testing. In this paper we suggest MLE of the reliability function for the Weibull distribution under the KG model. Futhermore, we compare Kaplan-Meier estimator, Nelson estimator, Cheng & Chang estimator, and Ebrahimi estimator with proposed estimator for the reliability function under the KG model.

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Reliability Estimation for a Shared-Load System Based on Freund Model

  • Hong, Yeon-Woong;Lee, Jae-Man;Cha, Young-Joon
    • Journal of the Korean Data and Information Science Society
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    • v.6 no.2
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    • pp.1-7
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    • 1995
  • This paper considers the reliability estimation of a two-component shared-load system based on Freund model. Maximum likelihood estimator, order restricted maximum likelihood estimator and uniformly minimum variance unbiased estimator of the reliability function for the system are obtained. Performance of three estimators for moderate sample sizes is studied by simulation.

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On the Estimation of Reliability Functions for the Freund Model

  • Hong, Yeon-Woong;Lee, Jae-Man;Cha, Young-Joon
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.1
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    • pp.79-83
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    • 1997
  • This paper considers the problem of estimating the model parameters and reliability functions for Freund bivariate exponential distribution. Uniformly minimum variance unbiased estimators for model parameters, joint reliability and marginal reliability functions are obtained in the both case of non-identically distributed marginals and identically distributed marginals.

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