• Title/Summary/Keyword: reliability factors

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A Study on the Reliability Prediction for Space Systems (우주 시스템의 신뢰성 예측에 관한 연구)

  • Yu, Seung-U;Lee, Baek-Jun;Jin, Yeong-Gwon
    • Aerospace Engineering and Technology
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    • v.5 no.2
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    • pp.227-239
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    • 2006
  • Reliability prediction provides a rational basis for design decisions such as the choice between alternative concepts, choice of part quality levels, derating factors to be applied, use of proven versus state-of-the-art techniques, and other factors. For this reasons, reliability prediction is essential functions in developing space systems. The worth of the quantitative expression lies in the information conveyed with the numerical value and the use which is made of that information and reliability prediction should be initiated early in the configuration definition stage to aid in the evaluation of the design and to provide a basis for item reliability allocation (apportionment) and establishing corrective action priorities. Reliability models and predictions are updated when there is a significant change in the item design availability of design details, environmental requirements, stress data, failure rate data, or service use profile. In this paper, the procedure, selection of reliability data and methods for space system reliability prediction is presented.

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The Effect of Website Characteristics and Online Service Quality of Kidult Online Shopping Mall on The Reliability and Repurchase Intention (키덜트 전문 쇼핑몰의 사이트 특성과 온라인 서비스 품질이 신뢰 및 재구매 의도에 미치는 영향)

  • Lee, Sang Won;Kim, Hong Keun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.4
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    • pp.161-178
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    • 2019
  • The purpose of this study is to analyze the effect of characteristics of the online shopping mall website and the service quality factors required on the online service on the reliability and repurchase intention. Through this, the key customer response service and operation management strategy can be proposed for the growth of kidult online shopping mall which is continuously spreading. Also, implications for development direction can be suggested. For this purpose, the ES-QUAL and E-Rec-S-QUAL factors proposed by Parasuraman et al.(2005) were set as independent variables, as well as professionalism, diversity, playfulness, and personalization, and website reliability as a mediating factor, and repurchase intention as a dependent variable. For the analysis, a structured questionnaires survey was conducted to 200 domestic online shopping mall users. The main results are as follows. First, the professionalism, personalization in the characteristics, and service quality factors had positive effects on website reliability. Second, playfulness, personalization in the characteristics, and service quality factors had positive effects on repurchase intention. Third, website reliability had a positive effect on repurchase intention. Fourth, website reliability was found to mediate the relationship between predictive (independent) variables and dependent variables. The above results show that if a professional online shopping mall is equipped with online service quality and establish personalization through enhancing the professionalism, the online shopping mall can form a website reliability and expect to build continuous relationship with customers. In addition, implications can be suggested for future customer response service and operation management strategies.

Resistance Factors of Driven Steel Pipe Piles for LRFD Design in Korea (LRFD 설계를 위한 국내 항타강관말뚝의 저항계수 산정)

  • Park, Jae Hyun;Huh, Jungwon;Kim, Myung Mo;Kwak, Kiseok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.6C
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    • pp.367-377
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    • 2008
  • As part of study to develop LRFD (Load and Resistance Factor Design) codes for foundation structures in Korea, resistance factors for static bearing capacity of driven steel pipe piles were calibrated in the framework of reliability theory. The 57 data sets of static load tests and soil property tests conducted in the whole domestic area were collected and these load test piles were sorted into two cases: SPT N at pile tip less than 50, SPT N at pile tip equal to or more than 50. The static bearing capacity formula and the Meyerhof method using N values were applied to calculate the expected design bearing capacities of the piles. The resistance bias factors were evaluated for the two static design methods by comparing the representative measured bearing capacities with the expected design values. Reliability analysis was performed by two types of advanced methods: the First Order Reliability Method (FORM), and the Monte Carlo Simulation (MCS) method using resistance bias factor statistics. The target reliability indices are selected as 2.0 and 2.33 for group pile case and 2.5 for single pile case, in consideration of the reliability level of the current design practice, redundancy of pile group, acceptable risk level, construction quality control, and significance of individual structure. Resistance factors of driven steel pipe piles were recommended based on the results derived from the First Order Reliability Method and the Monte Carlo Simulation method.

A Study on Comparison Analysis of the System Quality Factors between Korea and China Shopping mall Websites

  • Kwon, Young-Jik;Cui, Jun;Kwon, Donghwoon
    • Journal of Korea Multimedia Society
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    • v.16 no.11
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    • pp.1315-1324
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    • 2013
  • This paper mainly focuses on the system quality factors of a website targeted at shopping mall websites in China and Korea. We categorized six system quality factors and formulated hypotheses regarding how those six factors are different. We also conducted an empirical study to verify hypotheses. Statistical data for an empirical study targeted at undergraduate students in Korea and China, having filled in a questionnaire. Reliability of the collected data was measured, and a T-test of the established hypotheses was carried out. The following describes the results that were found. While the shopping mall websites of two countries showed a difference in terms of quick transition of the web pages or images, ease of use, reliability, and accessibility, they did not show the difference in term of accuracy and the short cut function. We analyzed the causes of the verified results and suggested a strategy to implement the effective shopping mall web sites.

Handling dependencies among performance shaping factors in SPARH through DEMATEL method

  • Zhihui Xu;Shuwen Shang;Xiaoyan Su;Hong Qian;Xiaolei Pan
    • Nuclear Engineering and Technology
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    • v.55 no.8
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    • pp.2897-2904
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    • 2023
  • The Standardized Plant Analysis Risk-Human Reliability Analysis (SPAR-H) method is a widely used method in human reliability analysis (HRA). Performance shaping factors (PSFs) refer to the factors that may influence human performance and are used to adjust nominal human error probabilities (HEPs) in SPAR-H. However, the PSFs are assumed to be independent, which is unrealistic and can lead to unreasonable estimation of HEPs. In this paper, a new method is proposed to handle the dependencies among PSFs in SPAR-H to obtain more reasonable results. Firstly, the dependencies among PSFs are analyzed by using decision-making trial and evaluation laboratory (DEMATEL) method. Then, PSFs are assigned different weights according to their dependent relationships. Finally, multipliers of PSFs are modified based on the relative weights of PSFs. A case study is illustrated that the proposed method is effective in handling the dependent PSFs in SPAR-H, where the duplicate calculations of the dependent part can be reduced. The proposed method can deal with a more general situation that PSFs are dependent, and can provide more reasonable results.

Development of the Burnout Scale for General Hospital Nurses (종합병원 간호사의 소진 측정도구 개발)

  • Lee, Sun-Mi;Shin, Hye Sook
    • Journal of East-West Nursing Research
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    • v.29 no.2
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    • pp.95-105
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    • 2023
  • Purpose: The purpose of this study was to develop a measurement tool for burnout in general hospital nurses and verify its reliability and validity. Methods: Construct factors were extracted through an extensive literature review and in-depth interviews with nurses. Psychometric testing was conducted with 550 nurses in a general hospital. Data were analyzed using validity and reliability testing. Results: As a result of factor analysis, 4 factors and 26 items were selected. The burnout factors of general hospital nurses were professional quality of life, work environment excellence, job satisfaction, and negative emotions. The overall coefficient of determination was 46.38%. These factors were validated through convergent, discriminant and concurrent validity testing. The internal consistency reliability was acceptable (Cronbach's α=.91). Conclusions: The Burnout Scale for General Hospital Nurses is a valid and reliable tool that contributes to the assessment of burnout in general hospital nurses. This scale is expected to be used in burnout practice and research of general hospital nurses.

The Impact of Psychological and Environmental Factors on Consumers' Purchase Intention toward Organic Food: Evidence from Vietnam

  • NGUYEN, Dinh Toan;TRUONG, Dinh Chien
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.1
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    • pp.915-925
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    • 2021
  • The study investigates some psychological and environmental factors affecting the intention to purchase organic foods of consumers in the inner-city of Hanoi. Impact factors applied for the study include three psychological factors (health concern, environmental concern, consumer awareness of organic foods) and seven environment factors (family's opinion, friends and colleagues' opinion, influence of celebrities, expert's opinion, social status, mass media, state's encouragement). We analyzed research data from 396 consumers to measure the impacting level of these factors. The convenient sampling method was used to collect the research sample. The measurement applied a 5-point Likert scale classifying from 1-completely disagree to 5-completely agree. Based on previous studies, the research model was recommended. We had estimated the reliability of the scales through Cronbach's Alpha and composite reliability. The research data is analyzed by using Structural Equation Model method (SEM). The findings of the study suggest that psychological factors (health concern, environmental concern, consumer awareness of organic foods) had a significantly positive influence on consumer's purchase attention toward organic food. The results also revealed that environmental factors (family's opinion, friends and colleagues' opinion, influence of celebrities, expert's opinion, mass media) were positively linked to consumer's purchase attention toward organic food.

Model for Predicting Ultrasonic NDE Reliability and Statistical Data Analysis of Piping Inspection Round Robin

  • Park, Ik-Keun;Kim, Hyun-Mook
    • International Journal of Reliability and Applications
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    • v.5 no.1
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    • pp.25-36
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    • 2004
  • Ultrasonic inspection system consist of the examination procedures, equipment, and operators. The reliability of nondestructive testing is influenced by the inspection environment, materials and types of defect. It is very difficult to estimate the reliability of NDT due to the various factors. Piping inspection round robin was conducted to quantify the capability of ultrasonic inspection during in-service. In this study, the models for predicting the ultrasonic NDE reliability by logistic model and linear regression model are discussed. The utility of the NDT reliability assessment is verified by the analysis of the data from round robin test with these models.

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A Study on Controlling the External Effect in Student Evaluation of Teaching

  • Lee S. W.;Lee K. H.
    • Communications for Statistical Applications and Methods
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    • v.12 no.3
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    • pp.589-601
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    • 2005
  • Student evaluation of university teaching is a common tool for measuring the educational contribution of a professor and improving the quality of classes. There, however, exist external factors in the beyond of control of a instructor, which affect the result of Student's rating to prevent practical use of evaluation for administrative purpose. This paper investigates the factors that spoil the validity and the reliability of student evaluation and proposes a method to control the effect by the statistical analysis of evaluation data of Jeonju University for two years.

Study on the Influence Factors for Accuracy of Simulation-based Reliability Calculation Methods (시뮬레이션 신뢰도 계산방법의 정확성에 대한 영향요인 연구)

  • Ren, Ziyan;Zhang, Dianhai;Koh, Chang-Seop
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1025-1026
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    • 2011
  • Monte Calrlo Simulation (MCS) and Sensitivity-based MCS (SMCS) are studied and compared in this paper. Quantitative analysis of the influence factors for reliability calculation accuracy is performed through a analytic function and finally applied to TEAM problem 22.

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