• Title/Summary/Keyword: reliability factors

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Safety factor calibration for bridge concrete girders

  • Silva, Rita C.;Cremona, Christian
    • Structural Engineering and Mechanics
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    • v.49 no.2
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    • pp.163-182
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    • 2014
  • Safety factors proposed in codes CEB, B.A.E.L 91 and EUROCODE 1 cover a great number of uncertainties; making them inadequate for the assessment of existing structures. Suitable safety factors are established using a probabilistic assessment, once real dimensions, materials strength and existing structures deterioration mechanisms are taken into account. This paper presents a calibration method for safety factors using a typical set of RC bridges in France. It considers the principal stages of corrosion provoked by $CO_2$ and $Cl^-$ penetration and threshold indexes (${\beta}_0$) for existing structures. Reliability indexes are determined by the FORM method in the calibration method.

Relationships among Service Quality of Brand Coffee Shop and Customer Satisfaction (브랜드 커피전문점의 서비스품질 및 고객 만족도의 관계: 중국 베이징 지역 중심으로)

  • Ma, Hong-Bo;Kim, Yeong-Gug
    • Asia-Pacific Journal of Business
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    • v.6 no.1
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    • pp.45-57
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    • 2015
  • The purpose of this research is to explore the relationships among service quality's five factors(i.e., tangibles, reliability, responsiveness, empathy, and assurance) and customer satisfaction. The study used convenience sampling and selected certain consumers who visited coffee shop in BeiJing, China. Total 300 questionnaires was distributed and 18 unsuitable data were excluded for data analysis. These data were tested using SPSS 21.0. The results of this study are summarized as follows. First, the result of the relationship between coffee shops'service quality and customer satisfaction reveals that two of 5 service quality factors (i.e., assurance and empathy) had a positive effect on customer satisfaction only, and other service quality factors (i.e., tangibles, reliability, and responsiveness) had no positive influence on customer satisfaction. Limitations and future research directions of the study were also discussed.

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Resistance Model for Reliability Analysis of Existing Steel Girder Bridges (강거더 교량의 신뢰성해석을 위한 저항모델 개발)

  • Eom, Jun Sik
    • Journal of Applied Reliability
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    • v.13 no.4
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    • pp.241-252
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    • 2013
  • Because of financial and safety concerns, there are needs for more accurate prediction of bridge behavior. Underestimation of the bridge load carrying capacity can have serious economic consequences, as deficient bridges must be repaired or rehabilitated. Therefore, the knowledge of the actual bridge behavior under live load may lead to a more realistic calculation of the load carrying capacity and eventually this may allow for more bridges to remain in service with or without minor repairs. The presented research is focused on the reliability evaluation of the actual load carrying capacity of existing bridges based on the field testing. Seventeen existing bridges were tested under truck load to confirm their adequacy of reliability. The actual response of existing bridge structures under live load is measured. Reliability analysis is performed on the selected representative bridges designed in accordance with AASHTO codes for bridge component (girder). Bridges are first evaluated based on the code specified values and design resistance. However, after the field testing program, it is possible to apply the experimental results into the bridge reliability evaluation procedures. Therefore, the actual response of bridge structures, including unintentional composite action, partial fixity of supports, and contribution of nonstructural members are considered in the bridge reliability evaluation. The girder distribution factors obtained from the tests are also applied in the reliability calculation. The results indicate that the reliability indices of selected bridges can be significantly increased by reducing uncertainties without sacrificing the safety of structures, by including the result of field measurement data into calculation.

The Reliability and Validity Test of Psychosocial Well-being Index(PWI) (사회심리적 건강 측정 도구의 신뢰도 및 타당도 검정)

  • 김정희
    • Journal of Korean Academy of Nursing
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    • v.29 no.2
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    • pp.304-313
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    • 1999
  • The purpose of this study is to test the reliability and validity test of PWI to utility of PWI. this newly developed by Sejin Jang which measures stress. The subject were 186 workers in service area. Cronbach's a and Guttman split-half coefficient is used to test the reliability of PWI. Factor analysis and the correlation of the GHQ-60. GHQ-30, GHQ-28, GHQ-20, and GHQ-12 with the PWI is used to convergent validity and discriminant validity. The important results of this study are as follows : Cronbach's $\alpha$ coefficient of data was 0.894 and Guttman split-half coefficient was 0.7097. The PWI was classified as 13 principle component (eigenvalue>1.0). After exploring 4 factor structure according to previous study result, 4 factors was explained 40.5% out of the total variance. The factor 1 was explained 15.9% and then the rest three factor was 24.6%. Factor 2 and 4 showed good agreement but factor 1 and 3 did not. Depression-related items were classified two factors. Anxiety and depression-related items were loaded unifactor. It was not clear that the PWI was consist of 4 concepts(factors). The correlation of the GHQ-60, GHQ-30, GHQ-28, GHQ-20, and GHQ-12 with the PWI were 0.744~0.905. According to findings of this study. the PWI showed a high degree of validity and reliability. Thus it is recommended to use the PWI in general setting for screening for stress. In addition, it is necessary to clarify the concept of depression and anxiety. In the further study. it my be considered to the factor structure of PWI and studied to two or unidimensional factor structure.

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Evaluation of Partial Safety Factors on Sliding of Monolithic Vertical Caisson of Composite Breakwaters (혼성제 직립 케이슨의 활동에 대한 부분안전계수 산정)

  • Lee, Cheol-Eung;Park, Dong-Heon;Kwon, Hyuk-Jae;Lee, Sun-Yong
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.21 no.4
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    • pp.267-277
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    • 2009
  • Partial safety factors of the load, resistance, and reliability function are evaluated according to the target probability of failure on sliding mode of monolithical vertical caisson of composite breakwaters. After reliability function is formulated for sliding failure mode of caisson of composite breakwaters regarding bias of wave force, uncertainties of random variables related to loads, strengths are analyzed. Reliability analysis for the various conditions of water depth, geometric, and wave conditions is performed using Level II AFDA model for the sliding failure. Furthermore, the reliability model is also applied to the real caisson of composite breakwaters of Daesan, Dong- hae, and Pohang harbor. By comparing the required width of caisson of composite breakwater according to target probability of failure with the other results, the partial safety factors evaluated in this study are calibrated straightforwardly. Even though showing a little difference on the 1% of target probability, it may be found that the present results agree well with the other results in every other target probability of failure.

The Reliability and Validity of a Drinking Refusal Self-Efficacy Questionnaire-Revised (DRSEQ-R) in Korean College Students (한국 대학생을 대상으로 한 음주거절효능감 도구 [Drinking Refusal Self-Efficacy Questionnaire-Revised: DRSEQ-R]의 신뢰도 및 타당도 검증)

  • Tak, Young-Ran;An, Ji-Yeon;Woo, Hae-Young
    • Journal of Korean Academy of Nursing
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    • v.38 no.2
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    • pp.344-352
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    • 2008
  • Purpose: This study was to test the reliability and validity of a Drinking Refusal Self-Efficacy Questionnaire-Revised (DRSEQ-R) in Korean college students, Methods: The DRSEQ-R was designed to assess an individual's belief in their ability to refuse drinking alcohol by Oei et al. (2005) and consisted of three factors (social pressure, opportunity, and emotional relief). A methodological study design with an exploratory factor analysis for validity and correlation coefficients for reliability was used. DRSEQ-R was translated into Korean and a translation equivalency was obtained. DRSEQ-R was tested with a sample of 201 college students in Korea. The subjects consisted of 106 males and 95 females. Principal component factor analysis was used for construct validity and Cronbach's alpha was used to evaluate for internal consistency of the instrument. Results: The factor analysis showed three factors explaining 66.3% of total variance and the corresponding factors were emotional relief (48.01%), drinking contextual opportunity (11.18%), and social pressure (7.14%). The internal consistency was acceptable (Cronbach's alpha=.937). All three factors of DRSEQ-R negatively correlated with alcohol dependency and a heavy drinker showed a lower DRSEQ-R than a moderate drinker. Conclusion: Based on the findings, DRSEQ-R is a reliable and valid instrument to measure for drinking refusal self-efficacy in Korean college students.

A Study on Public Data Quality Factors Affecting the Confidence of the Public Data Open Policy (공공데이터 품질 요인이 공공데이터 개방정책의 신뢰에 미치는 영향에 관한 연구)

  • Kim, Hyun Cheol;Gim, Gwang Yong
    • Journal of Information Technology Services
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    • v.14 no.1
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    • pp.53-68
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    • 2015
  • This article aims to identify the quality factors of public data which have increased as a public issue; analyze the impact of users satisfaction in the perspective of Technology Acceptance Model (TAM), and investigate the effect of service satisfaction on the government's open policy of public data. This study is consistent with Total Data Quality Management (TDQM) of MIT, it focuses on three main qualities except Contextual Data Quality (CDQ) and includes seven independent variables : accuracy, reliability, fairness for Intrinsic Data Quality (IDQ), accessibility, security for Accessibility Data Quality (ADQ), Consistent representation and understandability for Representational Data Quality (RDQ). Basing on TAM, the research model was conducted to examine which factors affect to perceived usefulness, perceived ease of use, service satisfaction and how service satisfaction affects to the government's open policy of public data. The results showed that accuracy, fairness, understandability affect both perceived ease of use and perceived usefulness; while reliability, consistent representation, security, and accessibility affect only perceived ease of use. This article found that the influence of perceived ease of use on perceived usefulness and the influence of these two causes on service satisfaction in the perspective of TAM were significant and it was consistent with prior studies. The service satisfaction when using public data leads to the reliability of public data open policy. As an initial study on unstructured public data open policy, this article offered quality factors that pubic data providers should consider and also present the operation plan of public data open policy in the future.

Standard Operating Procedure of Tongue-image Analysis System to Improve the Reliability (설진기 시스템의 혀 영상 획득과정에 대한 표준운영절차 제안)

  • Lee, Hyun-Joo;Kim, Su-Ryun;Nam, Dong-Hyun
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.20 no.2
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    • pp.51-65
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    • 2016
  • Objectives This study was conducted to suggest a standard operating procedure (SOP) in order to improve the reliability of tongue-image analysis system. Methods An affecting-factors list was made, which may affect the diagnostic parameters of the tongue-image analysis system. They were sub-classified into two groups: controllable and uncontrollable. Only the controllable factors, which could affect the results and easily set-up, were included into the SOP draft. Affecting factors control experiment was performed to investigate the effects of controllable factors, whose influence on diagnostic parameters of the tongue-image analysis system is ambiguous: rehearsal for tongue extrusion; alignment of camera axis; and presentation of a guideline. Three subjects volunteered for this experiment. Each of three variables was implemented twice in a random order by two operators on the subjects. Finally, 96 tongue images obtained in the aggregate. The diagnostic parameter set as a primary outcome in this experiment was the percentage of tongue coating. Results All of the control variables were not significant in both operators; however, the presentation of a guideline was relatively more affect than two other variables. Interaction effects among the variables were also insignificant. Therefore, the presentation of a guideline was included in the final SOP and the other variables were not included. Conclusions We suggested the SOP which could be used for both experimenter and subject. Moreover, Each of the SOPs applied to various types of tongue-image analysis system should be developed in order to improve the reliability.

Test of the Korean Parent as a Teacher (KPAAT) Inventory - Focusing on the Parents of Preschoolers - (한국형 교사로서의 부모 양육태도 검사도구 검증 - 학령전기 아동의 부모를 대상으로 -)

  • Kim, Young Hee;Kim, Kae Sook;Kim, Shin-Jeong
    • Child Health Nursing Research
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    • v.15 no.3
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    • pp.314-324
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    • 2009
  • Purpose: This study was done to test the reliability and validity of the Korean parent as a teacher (KPAAT) inventory for a group of parents of preschoolers. Methods: For this methodological study with 187parents were recruited from October to December, 2004 using convenience sampling. Self-report questionnaires measured level of child-rearing attitude. Internal consistency reliability was assessed with Cronbach's alpha coefficients. Construct validity of KPAAT inventory was analyzed using item analyses and factor analysis. Statistical analysis was done using SPSS Program Version 14.0. Results: The Cronbach's alpha coefficient for the KPAAT inventory was 0.881. For item analyses, inter-item correlation coefficients were -0.029${\sim}$0.781. Corrected item-total correlation coefficients were 0.012-0.737. Item-to"subscale correlation coefficients ranged from 0.509 to 0.817. Subscale-to-total correlation coefficients were 0.965, 0.711, respectively. Orthogonal varimax rotation of the 85 items in 16 areas of the KPAAT inventory, showed two factors, positive parenting attitude and negative parenting attitude. These two factors explained 48.2% of the total variance. Conclusion: In the original KPAAT inventory six factors were identified through factor analysis, however, in this study only two factors were extracted. Whereas, internal consistency reliability was within an acceptable range, these results suggest additional studies are needed to improve the validity of the KPAAT inventory.

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A Study of Hospital Choice on the Basis of Consumption Values Theory (소비가치 이론에 의한 병원선택 요인 연구)

  • Lee, Sun-Hee
    • Journal of Preventive Medicine and Public Health
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    • v.30 no.2 s.57
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    • pp.413-427
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    • 1997
  • This research is based on the Consumption Values Theory proposed by Sheth(1991). The purpose of this research is finding the factors related to the process of hospital choice. The expectation of six hospital outpatients 600 was analyzed by six consumption values categories: functional value, social value, emotional value, rarity value, condition value, health related values. The main results of this research is as following; 1. In the result of factor analysis 22 consumption value factors which affect the hospital preference were extracted; kindness/clearness, service speed, comfort of space, technical competence in functional values, high income/active social life, low income/blue collar unmarried/man, middle aged/big family, woman/married, introvert in social values, high-class, comfort, reliability in emotional value, newness, classiness in rarity value, social relationship, close to residence, social reputation in conditional values, priority on health, health behavior, active sense of value on health in health related values. 2. The difference of consumption values among hospital types were analyzed. The critical factors in reference for corporate hospitals newly established were kindness/clearness, service speed, convenience, classiness, comfort, and newness. University hospitals were preferred by the factors of reliability, and social reputation. In general hospital, convenience and close to residence were critical factor. 3. In logistic regression, age, marital status, education level and income as socio-demographic variables were significantly related to general hospital choice. Also service speed and close to residence were positively and high income/active social life and high class value were negatively related to general hospital choice. On university hospital choice, age and marital status, education show posive relationship whereas income showing negative relationship. Kindness/clearness, service speed, comfort of space, unmarried/man, comfortable feeling, newness and close to residence showed negative relationship with university hospital selection whereas technical competence, reliability in emotional value, classiness in rarity value, social relationship in functional values showed positive relationship. Lastly kindness/clearness, comfort of space, high income/active social life, unmarried/man, high-class, comfort and newness were positively related to corporate hospitals newly established choice in contrast to negative relationship in reliability in emotional value and classiness. In summary, we found that hospital user also choose to hospital in base of various consumption value. Further studies to investigate the hospital consumer behavior will be needed.

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