• Title/Summary/Keyword: Reliability measure

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Practical Application of Reliability Growth in Automotive New Product Cycle (자동차 개발에 있어서 심리팽창이론의 적용방법)

  • Jung, Won
    • IE interfaces
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    • v.12 no.1
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    • pp.158-165
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    • 1999
  • One solution to the estimation of product reliability during the development phase is to measure reliability improvement over time and compare this improvement to previous product development progress. This paper presents the reliability growth theory and applies it to some subsystems of vehicles during their design, development and prototype testing. The data presented illustrates explicitly the prediction of the reliability growth in the product development cycle. The application of these techniques is a part of the product assurance function that plays an important role in product reliability improvement.

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Software Reliability for Order Statistic of Burr XII Distribution

  • Lee, Jae-Un;Yoon, Sang-Chul
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.4
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    • pp.1361-1369
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    • 2008
  • The analysis of software reliability model provides the means to analysts, software engineers, and systems analysts and developers who want to predict, estimate, and measure failure rate of occurrences in software. In this paper, reliability growth model, in which the operating time between successive failure is a continuous random variable, is proposed. This model is based on order statistics of two parameters Burr type XII distribution. We propose the measure based on U-plot. Also the performance of the suggested model is tested on real data set.

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Inter-Rater Reliability of Chedoke-McMaster Stroke Assessment for Stroke Patients (뇌졸중환자 평가를 위한 Chedoke-McMaster Stroke Assessment의 측정자간 신뢰도)

  • Won, Jong-Hyuk;Kim, Yong-Wook
    • Physical Therapy Korea
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    • v.4 no.3
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    • pp.45-60
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    • 1997
  • This study was performed to determine the inter-rater reliability of the Chedoke-McMaster Stroke Assessment translated in Korean. This measures the physical impairments and disabilities that impact on the lives of individuals with stroke. The purposes of this measure were 1) to stage motor recovery to classify individuals in terms of clinical characteristics, 2) to predict rehabilitation outcomes, and 3) to measure clinically important change in physical function. Twenty-two subjects from physical therapy unit were assessed by two physical therapists. The ratings were compared by Spearman's rank correlation The correlation between two raters ranged from 0.85 to 0.98. Inter-rater reliability coefficient for total scores ranged from 0.95 to 0.97. This study confirms that the Chedoke-McMaster Stroke Assessment yields reliable results.

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A Study on the Development of the Scale for Measuring Perception of Equity in Marital Relationship (한국부부간 공평성 인지척도 개발에 관한연구)

  • 박정희
    • Journal of Families and Better Life
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    • v.16 no.2
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    • pp.107-122
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    • 1998
  • It has been suggested that equity theory a social psychological theory concerned with the fairness in casual relationships should be applicable to marital relationships. This study describes the development of the scale for measuring perception of equity which measure the level of equity in marital relationships among Korean couples. PES(Perception of Equity Scale) is composed of two subscales; detailed measure of equity(DME) and global measure of equity(GME). The PES which include items from two areas of concern for intimates-pschological-emotional concern day-to-day concern-are describes. As results of test reliability of areas of DME range from .86 to .88 and reliability of GME is .92. And there are primarily evidences of construct validity of PES. Therefore PES is very reasonable scale to measure of equity/inequity perception in married couples. Finally analyzing of the level of equity in this sample husbands and wives has generally equitable relationships with their partn rs. Another findings suggest that husbands are overbenefited of their patners through marriage whereas wives are not.

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Correlation Measure for Big Data (빅데이터에서의 상관성 측도)

  • Jeong, Hai Sung
    • Journal of Applied Reliability
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    • v.18 no.3
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    • pp.208-212
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    • 2018
  • Purpose: The three Vs of volume, velocity and variety are commonly used to characterize different aspects of Big Data. Volume refers to the amount of data, variety refers to the number of types of data and velocity refers to the speed of data processing. According to these characteristics, the size of Big Data varies rapidly, some data buckets will contain outliers, and buckets might have different sizes. Correlation plays a big role in Big Data. We need something better than usual correlation measures. Methods: The correlation measures offered by traditional statistics are compared. And conditions to meet the characteristics of Big Data are suggested. Finally the correlation measure that satisfies the suggested conditions is recommended. Results: Mutual Information satisfies the suggested conditions. Conclusion: This article builds on traditional correlation measures to analyze the co-relation between two variables. The conditions for correlation measures to meet the characteristics of Big Data are suggested. The correlation measure that satisfies these conditions is recommended. It is Mutual Information.

Measurement of Deformations in Micro-Area Using High Resolution AFM Scanning Moiré Technique (고분해능 원자 현미경 스캐닝 무아레 기법을 이용한 미소 영역의 변형량 측정)

  • Park, Jin-Hyoung;Lee, Soon-Bok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.31 no.6 s.261
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    • pp.659-664
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    • 2007
  • $Moire\'{e}$ interferometry is a useful technique to assess the reliability of electronic package because $Moire\'{e}$ interferometry can measure the whole-field and real-time deformations. The shear strain of a small crack site is important to the reliability assessment of electronic package. The optical limitation of $Moire\'{e}$ interferometry makes ambiguous the shear strain of a small area. An atomic force microscope (AFM) is used to measure the profile of a micro site. High resolution of AFM can apply to the $Moire\'{e}$ technique. AFM $Moire\'{e}$ technique is useful to measure the shear strain of a small area. In this research, the method to accurately measure the deformation of a small area by using AFM $Moire\'{e}$ is proposed. A phase-shifting method is applied to improve the resolution of AFM $Moire\'{e}$.

Determining the complexity level of proceduralized tasks in a digitalized main control room using the TACOM measure

  • Inseok Jang;Jinkyun Park
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4170-4180
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    • 2022
  • The task complexity (TACOM) measure was previously developed to quantify the complexity of proceduralized tasks conducted by nuclear power plant operators. Following the development of the TACOM measure, its appropriateness has been validated by investigating the relationship between TACOM scores and three kinds of human performance data, namely response times, human error probabilities, and subjective workload scores. However, the information reflected in quantified TACOM scores is still insufficient to determine the levels of complexity of proceduralized tasks for human reliability analysis (HRA) applications. In this regard, the objective of this study is to suggest criteria for determining the levels of task complexity based on logistic regression between human error occurrences in digitalized main control rooms and TACOM scores. Analysis results confirmed that the likelihood of human error occurrence according to the TACOM score is secured. This result strongly implies that the TACOM measure can be used to identify the levels of task complexity, which could be applicable to various research domains including HRA.

Optimum Design of Water Distribution Network with a Reliability Measure of Expected Shortage (부족량기대치를 이용한 배수관망의 신뢰최적설계)

  • Park, Hee-Kyung;Hyun, In-Hwan;Park, Chung-Hyun
    • Journal of Korean Society of Water and Wastewater
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    • v.11 no.1
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    • pp.21-32
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    • 1997
  • Optimum design of water distribution network(WDN) in many times means just reducing redundancy. Given only a few situations are taken into consideration for such design, WDN deprived of inherited redundancy may not work properly in some unconsidered cases. Quantifying redundancy and incorporating it into the optimal design process will be a way of overcoming just reduction of redundancy. Expected shortage is developed as a reliability surrogate in WDN. It is an indicator of the frequency, duration and severity of failure. Using this surrogate, Expected Shortage Optimization Model (ESOM) is developed. ESOM is tested with an example network and results are analyzed and compared with those from other reliability models. The analysis results indicate that expected shortage is a quantitative surrogate measure, especially, good in comparing different designs and obtaining tradeoff between cost and. reliability. In addition, compared other models, ESOM is also proved useful in optimizing WDN with reliability and powerful in controlling reliability directly in the optimization process, even if computational burden is high. Future studies are suggested which focus on how to increase applicability and flexibility of ESOM.

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A reliability measure of three dimensional shapes based on statistical shape analysis (통계적 형상분석을 이용한 3차원 형상의 신뢰도 계수)

  • Shin, Sang Min
    • The Korean Journal of Applied Statistics
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    • v.32 no.1
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    • pp.15-27
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    • 2019
  • The reliability of the data means the overall consistency of the measurement results. Methods for evaluating reliability have been continuously studied because it affects the results of the statistical analysis. Cronbach's ${\alpha}$ coefficient or intraclass correlation coefficient is used for reliability evaluation; however, these measures cannot be applied to data consisting of three-dimensional coordinates to represent an object. In this study, we propose a measure to evaluate the reliability of three dimensional shapes based on statistical shape analysis that is made possible by extracting the shape information from the measured three dimensional coordinates and decomposing the shape variation.

Implementation of Reliability Measure and Distribution (신뢰성 척도 및 분포의 적용)

  • Choi Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.7 no.5
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    • pp.175-184
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    • 2005
  • This paper presents the practial guide to implementation of reliability distributions. The applicability and property of various reliability distribution will then be illustrated. Main objective of this study is to present how to use reliability distributions summary with respect to the total life cycle management. This paper provides insight info the good aspects of using relability distributions properly.