• Title/Summary/Keyword: 형상모수

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Analysis of Software Reliability Growth Model with Gamma Family Distribution (감마족 분포를 이용한 소프트웨어 신뢰 성장 모형의 분석)

  • Kan, Kwang-Hyun;Jang, Byeong-Ok;Kim, Hee-Cheul
    • Journal of IKEEE
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    • v.9 no.2 s.17
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    • pp.143-151
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    • 2005
  • Finite failure NHPP models proposed in the literature exhibit is either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. For the sake of proposing shape parameter of the Gamma family distribution, used the special pattern. Data set, where the underlying failure process could not be adequately described by the knowing models, which motivated the development of the Gamma or Weibull model and Gompertz model. Analysis of failure data set that led us to the Gamma or Weibull model and Gompertz model using arithmetic and Laplace trend tests, bias tests was presented in this Paper.

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Estimating using the method of adaptive searching observation (적합탐색 관찰방법을 이용한 추정)

  • 변종석;남궁평
    • The Korean Journal of Applied Statistics
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    • v.9 no.2
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    • pp.145-159
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    • 1996
  • We propose an adaptive searching method using some spatial relations among sample points to estimate the interesting area in the spatial population. The fundamental idea is to observe the neighboring sample points when a sample point is satified with some condition of an adaptive searching observation. For obseving the sample points with this method to estimate the area the sample size is decreased. From this result, we may expect to reduce the cost and time consuming in observation the sample points and to draw the shape of the interesting area without prior information of an spatial population. Some analytical simulation results are also presented.

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Comparisons of Empirical Bayes Approaches to Censored Accelerated Lifetime Data (가속수명자료에 대향 경험적 베이즈 비료연구)

  • Cho, Geon-Ho;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • v.8 no.2
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    • pp.183-194
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    • 1997
  • In accelerated life tests, the failure time of an item is observed under a high stress level and based on the time, the failure rates of items we estimated at the normal stress level. In this paper, when the mean of the prior distribution of a parameter is known in Weibull lifetime model with censored failure time data, we study various estimating methods to obtain the empirical Bayes estimator of a parameter from the empirical Bayes approach under the normal stress level by considering the fact that the Bayes estimator is the function of prior parameters and of the acceleration parameter representing the effect of acceleration. And we compare the performance of several empirical Bayes estimators of a parameter in terms of the Bayes risk.

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A Study on the Evaluation of Linear Cumulative Damage Factor of Membrane Type LNG Tank by use of Probability Density Function (확률밀도함수를 이용한 멤브레인방식 LNG탱크의 선형누적손상도 평가에 관한 연구)

  • 김종호
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.6
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    • pp.993-999
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    • 2004
  • The estimation of fatigue life at the design stage of membrane type LNG tank is very important in order to arrive at feasible and cost effective solutions considering the total lifetime of the tank. In this study, the practical procedure of fatigue life prediction by use of cumulative damage factors based on Miner-Palmgren hypothesis and probability density function has been shown with the corner region of Gaz Transport Membrane type LNG tank being used as an example. In particular the parameters of Weibull distribution that determine the stress spectrum are discussed. The main results obtained from this study are as follows: 1. The recommended value for the shape parameter of Weibull distribution for the LNG tank is 1.1 in case of using the direct calculation method proposed in this study. 2. The calculated fatigue life is influenced by the shape parameter of Weibull distribution and stress block. The safe fatigue design can be achieved by using higher value of shape parameter and the stress blocks divided into more stress blocks.

The Comparative Study based on Gompertz Software Reliability Model of Shape Parameter (곰페르츠형 형상모수에 근거한 소프트웨어 신뢰성모형에 대한 비교연구)

  • Shin, Hyun Cheul;Kim, Hee Cheul
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.10 no.2
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    • pp.29-36
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    • 2014
  • Finite failure NHPP software reliability models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates per fault. In this paper, proposes the Gompertz distribution reliability model, which made out efficiency application for software reliability. Algorithm to estimate the parameters used to maximum likelihood estimator and bisection method, model selection based on mean square error (MSE) and coefficient of determination$(R^2)$, for the sake of efficient model, was employed. Analysis of failure using real data set for the sake of proposing fixed shape parameter of the Gompertz distribution was employed. This analysis of failure data compared with the Gompertz distribution model of shape parameter. In order to insurance for the reliability of data, Laplace trend test was employed. In this study, the proposed Gompertz model is more efficient in terms of reliability in this area. Thus, Gompertz model can also be used as an alternative model. From this paper, software developers have to consider the growth model by prior knowledge of the software to identify failure modes which can was helped.

Accelerated Life Test Design of an Electromagnetic Shielding Door Hinge (전자파 차폐도어용 힌지의 가속 수명 시험법 설계)

  • Kim, Do Sik;Cheong, Han Young
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.9
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    • pp.887-895
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    • 2017
  • This paper presents a study on the accelerated life tests of parts that operate during the opening and closing of door frames, particularly door hinges. Hinge theoretical verification and validation of the test equipment in the present study and the different structures and fault mode, depending on the purpose of usage analysis, failure mode for one of the hinges of the switchgear components used for electromagnetic shielding facilities and on-site operating conditions. The accelerated life test was designed for the characteristic lifetime prediction of the components, by estimating the shape parameter and the acceleration factor.

A Study on Accelerated Life Evaluation Method of Component for Automatic Transmission (자동변속기 구성품의 가속수명평가 방법에 관한 연구)

  • Lim, Hongsoo;Cho, Byungchul;Kim, Yunkyoo;Lee, Heeyong;Kim, Jaehoon
    • Transactions of the Korean Society of Automotive Engineers
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    • v.25 no.2
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    • pp.250-256
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    • 2017
  • Automatic transmission(A/T) is one of a car's core components. The durability of A/T has an effect on the durability of the car. The input shaft of A/T passes the power directly from the engine, so the durability of the input shaft for A/T is likewise vital. In this study, the test method of the input shaft is considered and the load spectrum of A/T is analyzed to secure durability of the input shaft. The shape parameter, T-N curve of the input shaft torsional fatigue test are obtained for life evaluation and analysis. Results of this study can be used to get the basic background of the durability test for A/T components.

Study on Accelerated Life-time Test of O-ring Rubber by Thermal Stress (열 스트레스에 의한 고무 오링의 가속수명시험에 관한 연구)

  • Shin, Young-Ju;Chung, Yu-Kyung;Choi, Kil-Yeong;Shin, Sei-Moon
    • Journal of Applied Reliability
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    • v.7 no.1
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    • pp.31-43
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    • 2007
  • The function of O-ring seals is to prevent leakage during the service life of the components in which they are installed. The life prediction of O-ring is very important at various industry fields. Generally, to evaluated the long-term performance of O-ring in severe environments has applied a life prediction technique based on accelerated life test (ALT). In this work, Accelerated thermal aging test(l20, 130, 140, $150^{\circ}C$) of O-ring was applied for life prediction of O-ring. The property changes after thermal aging test was measured using TGA, DSC, FT - IR, Video Microscope and SEM. Shape parameter and life prediction were obtained using MINITAB program.

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A Comparison of Reliability Factors of Software Reliability Model Following Lifetime Distribution Dependent on Pareto and Erlang Shape Parameters (파레토 및 어랑 형상모수에 의존한 수명분포를 따르는 소프트웨어 신뢰성 모형에 대한 신뢰도 특성요인 비교 연구)

  • Kim, Hee Cheul;Moon, Song Chul
    • Journal of Information Technology Applications and Management
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    • v.24 no.2
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    • pp.71-80
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    • 2017
  • Software reliability is one of the most elementary and important problems in software development In order to find the software failure occurrence, the instantaneous failure rate function in the Poisson process can have a constant, incremental or decreasing tendency independently of the failure time. In this study, we compared the reliability performance of the software reliability model using the parameters of Pareto life distribution with the intensity decreasing pattern and the shape parameter of Erlang life distribution with the intensity increasing and decreasing pattern in the software product testing. In order to identify the software failure environment, the parametric estimation was applied to the maximum likelihood estimation method. Therefore, in this paper, we compare and evaluate software reliability by applying software failure time data. The reliability of the Erlang and Pareto life models is shown to be higher than that of the Pareto lifetime distribution model when the shape parameter is higher and the Erlang model is more reliable when the shape parameter is higher. Through this study, the software design department will be able to help the software design by applying various life distribution and shape parameters, and providing basic knowledge using software failure analysis.

A Study on the Property Analysis of Software Reliability Model with Shape Parameter Change of Finite Fault NHPP Erlang Distribution (유한고장 NHPP 어랑분포의 형상모수 변화에 따른 소프트웨어 신뢰성 모형의 속성 분석에 관한 연구)

  • Min, Kyung Il
    • Journal of Information Technology Applications and Management
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    • v.25 no.4
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    • pp.115-122
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    • 2018
  • Software reliability has the greatest impact on computer system reliability and software quality. For this software reliability analysis, In this study, we compare and analyze the trends of the properties affecting the reliability according to the shape parameters of Erlang distribution based on the finite fault NHPP. Software failure time data were used to analyze software failure phenomena, the maximum likelihood estimation method was used for parameter estimation. As a result, it can be seen that the intensity function is effective because it shows a tendency to decrease with time when the shape parameters a = 1 and a = 3. However, the pattern of the mean value function showed an underestimation pattern for the true values when the shape parameters a = 1 and a = 2, but it was found to be more efficient when a = 3 because the error width from the true value was small. Also, in the reliability evaluation of the future mission time, the stable and high trend was shown when the shape parameters a = 1 and a = 3, but on the contrary, when a = 2, the reliability decreased with the failure time. Through this study, the property of finite fault NHPP Erlang model according to the change of shape parameter without existing research case was newly analyzed, and new research information that software developers can use as basic guideline was presented.