• 제목/요약/키워드: Reliability measure

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소프트웨어의 일정테스트노력과 웨이불 테스트 노력의 비교 연구 (A Study on the Reliability Comparison of S/W between Uniform Testing and Weibull Testing)

  • 최규식;김용경
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2006년도 춘계 종합학술대회 논문집
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    • pp.444-447
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    • 2006
  • 본 논문에서는 소프트웨어 테스트 단계중에 발생되는 테스트노력 소요량을 고려한 소프트웨어 신뢰도 성장 모델을 제시하여 시간종속적인 테스트 노력소요량 동태를 일정 테스트 노력일 때와 웨이블 테스트 노력일 때를 비교하여 연구한다. 소프트웨어 신뢰도 척도에 대한 데이터 분석기법을 개발하도록 한다. 테스트 시간의 경과와 신뢰도와의 관계도 심도 있게 연구한다. 목표신뢰도를 만족시키는 최적발행시각을 정한다. 개발 후 테스트를 시작하기 전의 신뢰도가 어떠한 조건에 있는가를 검토하여 각 조건에 따른 최적 발행시각을 결정한다.

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소프트웨어 시험 전략과 신뢰도 모델적응 연구 (A Study of the Software Testing Methods and fitness of the Reliability Models)

  • 문숙경
    • 품질경영학회지
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    • 제29권4호
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    • pp.92-102
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    • 2001
  • Software testing during development and operation should exercise to obtain the desired software quality and leave failure data set. So far, many software reliability models are classified and can be used to measure a software reliability only based on its failure history But, in practice, developers or testers of software systems must decide which existing software reliability model can be fitted. In this paper, we will show that an appropriate reliability model can be selected by considering relations between characteristics of each testing environment and models' assumptions. Several methods of software testing are presented and discussed. Also, unit test, integrated test, function test and system test that are sequentially exercised during development will be introduced.

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Permutation Analysis of Split-Half Reliability Coefficient

  • Um, Yonghwan
    • 한국컴퓨터정보학회논문지
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    • 제22권7호
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    • pp.133-139
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    • 2017
  • In this paper, we describe a permutation procedure in which we compute a resampling probability value and empirical quantile limits for Split-Half measure of internal reliability. We use the Split-Half reliability coefficient given by two simple methods, the Spearman-Brown formula and the two-part coefficient alpha. The use of a permutation test for Split-Half reliability coefficient is highlighted as a valuable tool when the sample sizes are small and necessary assumptions cannot be met. The permutation tests for Split-Half reliability coefficient are illustrated with an example analysis of two survey data with a sample size of 15 and 35, respectively, and a hypothetical data with a sample size of 5.

A fuzzy reasonal analysis of human reliability represented as fault tree structure

  • 김정만;이상도;이동춘
    • 대한인간공학회지
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    • 제16권2호
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    • pp.1-14
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    • 1997
  • In conventional probability-based human reliability analysis, the basic human error rates are modified by experts to consider the influences of many factors that affect human reliability. However, these influences are not easily represented quantitatively, because the relation between human reliability and each of these factors in not clear. In this paper, the relation is expressed quantitatively. Furthermore, human reliability is represented by error possibilities proposed by Onisawa, which is a fuzzy set on the interval [0,1]. Fuzzy reasoning is used in this method in order to obtain error possibilities. And, it is supposed that many basic events affected by the above factors are connected to the top event through Fault Tree structure, and an estimate of the top event expressed by a member- ship function is obtained by using the fuzzy measure and fuzzy integral. Finally, a numerical example of human reliability analysis obtained by this method is given.

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환경의식의 측정을 위한 설문지 개발과 검증 (Devleopment and Verification of Questionnaire for Measurement of Environmental Attitude)

  • 우형택;엄붕훈;문연화
    • 한국환경과학회지
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    • 제8권5호
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    • pp.559-568
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    • 1999
  • This study was conducted to develop the questionnaire for the measurement of environmental attitudes and test its reliability and validity. Development and valiadation of the 46 survey items that measure environmental attitudes were described. The total of 3 surveys were conducted and the total of 510 persons including diverse sample groups were questionnaired. The SAS $PC^+$ package program was used in both the reliability analysis and the validity analysis of surveyed data. Results revealed the very high reliability and the high validity of the questionnaire. The reliability of the finalized questionnaire was increased to the level of Cronbach-$\alpha$ 0.92 after the repeated reliability analyses and revisions of the firstly and secondly designed questionnaires. The validity of our questionnaire was sufficiently affirmed through the use and aplication of factor analysis and known-groups technique.

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Exploring Graphically and Statistically the Reliability of Medium Density Fiberboard

  • Guess, Frank M.;Edwards, David J.;Pickrell, Timothy M.;Young, Timothy M.
    • International Journal of Reliability and Applications
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    • 제4권4호
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    • pp.157-170
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    • 2003
  • In this paper we apply statistical reliability tools to manage and seek improvements in the strengths of medium density fiberboard (MDF). As a part of the MDF manufacturing process, the product undergoes destructive testing at various intervals to determine compliance with customer′s specifications. Workers perform these tests over sampled cross sections of the MDF panel to measure the internal bond (IB) in pounds per square inches until failure. We explore both graphically and statistically this "pressure-to-failure" of MDF. Also, we briefly comment on reducing sources of variability in the IB of MDF.

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한국어판 기후 건강관련 간호사 인지행동 측정도구의 타당도와 신뢰도 (Validity and Reliability of the Korean Version of the Climate, Health, and Nursing Tool)

  • 정다운;김광숙;박민경
    • 대한간호학회지
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    • 제52권2호
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    • pp.173-186
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    • 2022
  • Purpose: Climate change has various negative effects on human health, which has resulted in increased burden on the health care system. Nurses contribute significantly to assessing climate-related health risks and creating a healthy environment. This study aimed to evaluate the reliability and validity of the Korean version of the Climate, Health, and Nursing Tool (K-CHANT) to measure nurses' awareness, motivation, concern, and behaviors at work and at home regarding climate change and health. Methods: The 22 items of English CHANT were translated into Korean with forward-backward translation techniques. Internal consistency reliability, test-retest reliability, and construct validity using confirmatory factor analysis were performed using SPSS WIN (25.0) and AMOS (26.0). Survey data were collected from 220 master's, doctoral, and post-doctoral nursing students. Results: The K-CHANT consists of 20 items across 5 domains. Two items of the original CHANT were excluded because of low content validity index and standardized regression weights. The internal consistency reliability of the K-CHANT, assessed by Cronbach's α was .81, with an intraclass correlation coefficient of .66~.90. The five subscales model was validated by confirmatory factor analysis (SRMR < .08, RMSEA < .08, AGFI > .70, CFI > .70). Conclusion: The K-CHANT has satisfactory construct validity and reliability to measure nurses' awareness, motivation, concern, and behaviors at work and at home regarding climate change and health. Future research should examine nurses' perceptions and behaviors related to the health effects of climate change and develop an action plan to improve it.

Reliability index for non-normal distributions of limit state functions

  • Ghasemi, Seyed Hooman;Nowak, Andrzej S.
    • Structural Engineering and Mechanics
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    • 제62권3호
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    • pp.365-372
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    • 2017
  • Reliability analysis is a probabilistic approach to determine a safety level of a system. Reliability is defined as a probability of a system (or a structure, in structural engineering) to functionally perform under given conditions. In the 1960s, Basler defined the reliability index as a measure to elucidate the safety level of the system, which until today is a commonly used parameter. However, the reliability index has been formulated based on the pivotal assumption which assumed that the considered limit state function is normally distributed. Nevertheless, it is not guaranteed that the limit state function of systems follow as normal distributions; therefore, there is a need to define a new reliability index for no-normal distributions. The main contribution of this paper is to define a sophisticated reliability index for limit state functions which their distributions are non-normal. To do so, the new definition of reliability index is introduced for non-normal limit state functions according to the probability functions which are calculated based on the convolution theory. Eventually, as the state of the art, this paper introduces a simplified method to calculate the reliability index for non-normal distributions. The simplified method is developed to generate non-normal limit state in terms of normal distributions using series of Gaussian functions.

한글판 작업과제 몰입상태척도(Korean version of Flow State Scale for Occupational Task: K-FSSOT)의 타당도 및 신뢰도연구 (Validity and Reliability of a Korean Version of the Flow State Scale for Occupational Task)

  • 이정훈;박지혁
    • 재활치료과학
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    • 제10권4호
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    • pp.53-63
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    • 2021
  • 목적 : 본 연구는 작업치료 활동에서 대상자의 몰입상태정도를 측정하는 한글판 작업과제 몰입상태척도(Korean version of Flow State Scale for Occupational Task: K-FSSOT)를 개발하는 것이다. 연구방법 : 한글판 작업과제 몰입상태척도 개발을 위해 체계적인 번안과정을 거쳐 타당도 및 신뢰도 검증을 하였다. 타당도 검증은 작업치료사 10명의 내용타당도와 환자 20명의 문항이해도 조사를 통해 CVI 값을 산출하였다. 신뢰도 검증은 환자 33명의 내적일치도 및 검사-재검사 신뢰도를 조사하였다. 결과 : 내용타당도의 문항별 I-CVI 값은 .90~1.00으로 나타났고, 전체 항목의 평균인 S-CVI 값은 .97로 적절한 것으로 확인되었다. 신뢰도 검증 결과 전체 문항의 내적일치도 값은 .855로 높은 수준으로 나타났으며, 검사-재검사 신뢰도 값은 .894(p<.01)로 높은 상관관계를 보임으로 높은 신뢰도가 확인되었다. 결론 : K-FSSOT가 대상자의 참여와 몰입을 고민하는 작업치료사에게 작업치료 활동을 수행하는 대상자의 몰입상태정도를 측정하는데 유용한 도구로 활용되기를 기대한다.

이동최소자승근사법을 이용한 개선된 신뢰도 기반 최적설계 (An Improved Reliability-Based Design Optimization using Moving Least Squares Approximation)

  • 강수창;고현무
    • 대한토목학회논문집
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    • 제29권1A호
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    • pp.45-52
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    • 2009
  • 기존의 구조물의 설계에서는 안전성 및 경제성 등을 향상시키기 위해서 시방서에 명시된 설계지침을 제약조건으로 하여 확정론적 최적설계를 수행하는 것이 일반적이다. 하지만, 구조물의 설계에는 본질적으로 재료성질, 작용하중 및 시공오차 등의 불확실성이 내포되어 있으며, 이러한 불확실성과 경제성을 동시에 고려한 설계가 보다 더 합리적인 설계라 할 수 있다. 기존의 확정론적 최적설계에서는 이러한 불확실성을 고려하기 위하여 결정론적인 안전율을 도입하여 설계하지만, 이러한 경우 각 한계상태 및 파괴모드에 대한 일관된 안전성 및 신뢰도 수준을 확보하지 못한다. 최근에 이러한 불확실성 및 경제성을 동시에 고려하는 신뢰도 기반 최적설계에 대한 연구가 수행되고 있다. 신뢰도 기반 최적설계는 확률구속조건을 평가하는 방법에 따라 RIA(reliability index approach) 및 PMA(performance measure approach)로 구분된다. 일반적으로 PMA가 RIA 보다 안정성 및 효율성 측면에서 더 우수하다는 비교연구가 수행된 바 있다. 하지만 아직도 대형구조해석을 필요로 하는 경우에는 계산비용이 과다하여 최적설계가 불가능하므로 보다 개선된 신뢰도 기반 최적설계 알고리즘이 필요하다고 할 수 있다. 본 연구에서는 계산비용을 줄이면서도 안정적으로 수렴하는 개선된 신뢰도 기반 최적설계 알고리즘을 제안한다. PMA에 적합한 응답면 기법을 개발하였으며, 한계상태식의 근사는 이동최소자승근사법을 사용하였다. 이로부터 더 적은 표본점의 추출만으로 더욱더 정확한 응답면 함수를 얻게 되어 정확도 및 효율성을 개선할 수 있었다. 수학적 문제 및 10-bar truss 문제에 대하여 제안된 방법을 적용한 결과, 수렴성 및 효율성 측면에서 우수한 성능을 보여줌을 확인하였다.