• Title/Summary/Keyword: Reliability concept

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Formulation for Reliability-based Fatigue Assessment of Car Body for High Speed Train Passing Through Tunnels (터널을 통과하는 고속열차 차체의 피로신뢰성 평가의 정식화)

  • Seo Sung-Il;Min Oak-Key;Park Choon-Soo
    • Journal of the Korean Society for Railway
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    • v.8 no.4
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    • pp.348-353
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    • 2005
  • In designing the structures of railway rolling stocks, deterministic methods associated with the concept of a safety factor have been traditionally used. The deterministic approaches based on the mean values of applied loads and material properties have been used as safety verification for the design of rolling-stock car body structures. The uncertainties in the applied loading for the high speed train and the strength of new materials in the rolling stocks require the application of probabilistic approaches to ensure fatigue safety in the desired system. Pressure loadings acting on the car body when the train passes through tunnels show reflected pressure waves for high-speed trains and they may cause a fatigue failure in vehicle bodies. Use of new material technology as body structures also introduces uncertainties in the material strength. A probabilistic approach is more adaptable in designing reliable structures when the pressure waves from the tunnels pounds and new material technology is adopted. In this paper, it is proposed that a fatigue design and assessment method based on a reliability which deals with the loading variations on a railway vehicle due to the pressure reflected in tunnels and the strength variations of material. Equation for the fatigue reliability index has been formulated to calculate the reliability assessment of a vehicle body under fluctuating pressure loadings in a tunnel. Considered in this formulation are the pressure distribution characteristics, the fatigue strength distribution characteristics, and the concept of stress-transfer functions due to the pressure loading.

Investigation of Research Trends in the Selective Functional Movement Assessment (SFMA) (선택적 기능 동작 평가의 연구 동향 분석)

  • Kim, Jae-Eun;Do, Kwang-Sun
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.2
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    • pp.63-73
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    • 2021
  • Purpose : Selective functional movement assessment(SFMA) is a movement-based assessment tool designed for clinicians to diagnose and treat pain and functional physical problems. This concept is used for assistance in occupations related to movement, including clinical medical personnel, such as physical therapists, physical education instructors, and athlete coaches. Although this concept is widely used by clinicians, research and scientific proofs are relatively insufficient. This study aimed to review the literature on the understanding, reliability and effectiveness of SFMA, and to consider its role in the future of rehabilitation. Methods : In this review, a total of nine articles were selected according to the eligibility criteria of three major thesis topics. The main topics covered in the literature are reliability and effectiveness of clinical use of SFMA. To gather research articles, we searched official term 'Selective Functional Movement Assessment'. Among the searched 60 studies, nine were mentioned in this study that contained overlapping information and matched our desired topic. We reviewed four reliability analyses, four case reports, and one experimental study. Results : Reliability has an intermediate degree between high raters and within raters. The validity of the SFMA system is influenced by a combination of experience and logic; hence, further improvement is needed. Therefore, if the intervention was effective based on the diagnosis result, then biomechanical evidence is necessary to further support the claim. Conclusion : In future research, to use SFMA as a diagnostic tool with high accuracy, it is necessary to improve the reliability of the main problem through breakout, support for guidelines and validity and efficiency.

The Development of Satisfaction Tool to Health Care Services - focused on Patients and their families - (의료 서비스에 대한 만족도 측정 도구의 개발)

  • Kang, So-Young;Lee, Sun-Mi
    • Quality Improvement in Health Care
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    • v.3 no.1
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    • pp.104-124
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    • 1996
  • Background : In these days, the health care organizations have concerned about customer-centered care in order to empower the competitiveness on the health care markets. The departments working for quality management of the hospitals have used health care quality indicators in terms of medical areas as well as service areas of the hospitals. However, there were insufficient efforts to develop the credible measurement to seek the customers' needs, their expectations and their satisfaction levels related to health care services because various kinds of challenges were in the process of scale development to measure customers' satisfaction in health care. The purpose of this study was to develop the satisfaction scale to health care services in a Korea health care organization and to test its tool with validity and reliability. Method : The concept of this tool was acceptability that one of the components of health care quality defined by Donabedian. Acceptability has the five dimensions of concept: Accessibility; Patient-Practitioner Relations; Amenities; Patient Preferences as to the effects of care; and Patient Preferences as to the costs of care. The Satisfaction Tool to Health Care Services was reviewed by expert panel with five researchers, including hospital managers and a professor related to quality management of the hospitals. As a result, the content validity index was .84 in the outpatient satisfaction tool. The inpatient satisfaction tool had .87 of the content validity index. The Satisfaction Tools to Health Care Services finally consisted of 44 items for outpatients/their families and of 60 items for inpatients/their families. Study subjects of the construct validity test were 479 outpatients/their families and 561 inpatients/their families who visited or admitted at a University hospital from July 1, 1996 through August 10, 1996. The data were examined by Factor Analysis with SPSS. Result : The items of Satisfaction tools for outpatients/their families were categorized by eleven factors with eigenvalue greater than 1.0 accounting for 64.2 percent of the variation in item scores. Also, the items of inpatient tool had eleven factors with eigenvalue greater than 1.0 accounting for 60.3 percent of the variation in item scores. The reliability of overall scale were .95 and .96 for the outpatients/their families satisfaction scores and inpatient/their families satisfaction scores. The internal consistency reliability with eleven factors was ranged from .30 to .94 for inpatients/their families. The Satisfaction Tool with eleven factors for inpatients/their families had internal consistency reliability ranged from .53 to .89. Conclusion : The Satisfaction Tools to Health Care Services focused on outpatients/their families and inpatients/their families developed in this study had a high reliability and the strong evidence of content validity and construct validity based on quality concept. Therefore, this tool would be utilized as a credible quality indicator of health care services to assess the quality problems and to monitor the quality improvement activities in Korean Health Care Organizations.

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An Analytical Study of the Professional Self-Concept of Hospital Nurses in Korea (임상간호사의 전문직 자아개념에 관한 연구)

  • 송경애;노춘희
    • Journal of Korean Academy of Nursing
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    • v.26 no.1
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    • pp.94-106
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    • 1996
  • Nursing literature suggests that the self-concept of nurses gives an important implications to educators and administrators as well as clinicians for their professional development. With a view to exploring how nurses view themselves, the Professional Self-Concept of Nurses Instrument (PSCNI) using 27 Likert items was developed by Arthur in Australia in 1990. This study is an extension of the PSCNI using Korean samples with some modifications. A convenience sample was drawn from 800 nurses working in three university hospitals in Seoul ; three university hospitals in Kyonggi-do and a university hospital and a psychiatric hospital in Kangwon-do. Seven hundred questionnaires were analyzed using the statistical analysis system(SAS). The reliability of the scale was tested by test-retest and Cronbach's alpha. Differences in the PSCNI, which are closely related to demographic variables, were examined by t-test, ANOVA and the Duncan's multiple range test. Factor analysis was employed so as to examine component factors. The results are summarized as follows : 1. The test-retest reliability of the PSCNI was .79 and Cronbach's alpha was .85. Item correlations with total revealed consistent correlations and subscale reliability varied from .49 to .85. 2. The average score of PSCNI was 75.21 and average item score was 2.79. 3. Twenty four items were derived from the PSCNI 27 items and these items clustered in three component factors. The cumulative percent of variance was 38.12% and for factor 1 was 22.81%, for factor 2, 9.79% and for factor 3, 5.51% respectively 4. A comparison of the scores for the dimensions of the PSCNI shows a relative difference in terms of mean item scores and in descending order, professional practice(m=2.83), communication (m=2.82) and satisfaction(m=2.70). 5. Professional self-concept of nurses was found to vary significantly according to age(P=.0001), religion(P=.0001), academic background(P= .0109), marital status(P=.0001), career(P= .0001) and position(P=.0001). In conclusion, there was a correlation between professional self-concept of nurses, and life and work variables. This study provides an important message for administrators and nurse educators by highlighting factors which can be addressed by education programs, staff development and appraisal. While the test results largely confirm the Australian and Canadian tests, further research is necessary to improve the cumulative percent of variance instead of applying Arthur's PSCNI directly to Korean nurses.

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Beyond Categories: A Structural Analysis of the Social Representations of Information Users' Collective Perceptions on 'Relevance'

  • Ju, Boryung;O'Connor, Daniel O.
    • Journal of Information Science Theory and Practice
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    • v.1 no.2
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    • pp.16-35
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    • 2013
  • Relevance has a long history of scholarly investigation and discussion in information science. One of its notable concepts is that of 'user-based' relevance. The purpose of this study is to examine how users construct their perspective on the concept of relevance; to analyze what the constituent elements (facets) of relevance are, in terms of core-periphery status; and to compare the difference of constructions of two groups of users (information users vs. information professionals) as applied with a social representations theory perspective. Data were collected from 244 information users and 123 information professionals through use of a free word association method. Three methods were employed to analyze data: (1) content analysis was used to elicit 26 categories (facets) of the concept of relevance; (2) structural analysis of social representations was used to determine the core-periphery status of those facets in terms of coreness, sum of similarity, and weighted frequency; and, (3) maximum tree analysis was used to present and compare the differences between the two groups. Elicited categories in this study overlap with the ones from previous relevance studies, while the findings of a core-periphery analysis show that Topicality, User-needs, Reliability/Credibility, and Importance are configured as core concepts for the information user group, while Topicality, User-needs, Reliability/Credibility, and Currency are core concepts for the information professional group. Differences between the social representations of relevance revealed that Topicality was similar to User-needs and to Importance. Author is closely related to Title while Reliability/Credibility is linked with Currency. Easiness/Clarity is similar to Accuracy. Overall, information users and professionals function with a similar social collective of shared meanings for the concept of relevance. The overall findings identify the core and periphery concepts of relevance and their relationships in terms of coreness, similarity, and weighted frequency.

A Study on the Development of the Korean Family Resilience Scale (한국가족의 기능 회복력 측정도구 개발 연구 - 만성질환아 가족을 대상으로 -)

  • ;;;;Hesook Suzie, Kim
    • Journal of Korean Academy of Nursing
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    • v.32 no.4
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    • pp.560-569
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    • 2002
  • The purpose of this study was to develop an instrument to measure family resilience for Korean families with a chronically ill child, and to test the validity and reliability of the instrument. Method: The items of instruments used based on the researchers' previous study of concept analysis of Korean family resilience. Nineteen item scales were developed with five domains. In order to test reliability and validity of the scale, data were collected from 231 families, who had a child with a chronic illness. Data was collected between August and September of 2001 in a 3rd level University Hospital in Seoul, Korea. Result: The results were as follows: As a result of the item analysis, 19 items were selected from the total of 37 items, excluding items with low correlation with the total scale. Five factors were evolved by factor analysis, which explained 56.4% of the total variance. The first factor 'Family strength' explained 28.5%, 2nd factor 'Family maturity' 8.7%, 3rd factor 'The ability to use of external resources' 7.0%, 4th factor 'Control' 6.6%, 5th factor 'The driving force for finance' 5.7%. The attributes in these factors were different with those identified by concept analysis of the family resilience in Korean families from the previous study. Cronbach's $\alpha$ coefficient of this scale was .8039 and Guttman spilt- half coefficient was .8184. Conclusion: The study support the reliability and validity of the scale. Because the main concept of family resilience was family strength, there were distinct differences in dimensions of family functioning scales.

On the Reliability of the Computational Fire Model Based on the Yield Rate Concept of Combustion Gases (생성율 개념에 기초한 화재모델의 신뢰성에 대한 연구)

  • Kim, Sung-Chan;Ko, Gwon-Hyun;Lee, Seong-Hyuk
    • Fire Science and Engineering
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    • v.23 no.4
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    • pp.130-136
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    • 2009
  • The present study has been performed to evaluate the reliability of the fire field model (FDS version 5.2) with yield rate concept of combustion products. The CO and smoke density predicted by FDS model was directly compared with measurement in a reduced scale ISO-9705 room. The GER (global equivalence ratio) concept was used to characterize the CO and smoke density with ventilation condition in the fire compartment. The FDS model tends to under-predict CO concentration and smoke density than those of measurement for the under-ventilated conditions. Also, the discrepancy between predicted and measured result increases as GER increases. In order to improve the reliability of the fire model for performance evaluation of fire safety, the fire model is necessary to be validated in various fire cases as well as develop detailed physical model.

Collaborative Relationship Analysis between Members of Apartment Construction Organizations

  • Kim, Jae-Yeob
    • Journal of the Korea Institute of Building Construction
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    • v.14 no.1
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    • pp.102-109
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    • 2014
  • The purpose of this study is to analyze collaborative relationship between members of a building construction organization. For the analysis of collaborative relationship, this researcher collected data by conducting a questionnaire survey with members of three large building construction organizations for apartment housing. The analyzed contents of collaborative relationship were the 'frequency of communication between organizational members' and their 'reliability'. According to the analysis of communication network, construction managers had low frequency of communication, whereas those responsible for each area, like construction deputy managers, had high frequency of communication. It indicates that middle managers are at the center of communication related to construction work in construction organizations. According to the analysis of reliability network, construction managers showed highest reliability, and employees at the top level in an organizational map also showed high reliability. Since they generally have a lot of experience, are some older of age, and assume responsibility for work, they are considered to receive reliability from other organizational members. This study proved that it was possible to numerically express reliability of organizational members, which is an abstract concept, and analyze it. Therefore, it is expected that the analysis result will highly be likely to be used in the area of construction management.

THE DESIGN OF AN OPTIMAL SPARE KIT FOR WEAPON SYSTEMS

  • Oh Kwan-Chi
    • Journal of the military operations research society of Korea
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    • v.1 no.1
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    • pp.131-135
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    • 1975
  • One of the pending issues of the Ministry of Defense is the efficient management of space parts for the weapon systems. It has been known that more than 000 million dollars are needed for spare parts for the weapon systems annually. Though the problem demands a serious consideration, there has not been any systematic study on the problem as far as the author knows. One way to approach the problem is through an investigation of the system reliability under constraints. A measure of how well a system performs or meets its design objectives is provided by the concept of system reliability. If successful operation is desired for a specified period of time, reliability is defined as the probability that the system will perform satisfactorily for the required time period. This interpretation of reliability is normally applied to devices which are subject to random failures such as electrical or mechanical systems. It has been found necessary to express system reliability in terms of the reliability of the components or subsystems which comprise the system. The major subsystems of an aircraft, for example, include the electronics, powerplant, airframe and armament subsystems. Therefore, the optimal spare part kit can be found by maximizing the system reliability subject to cost or other constraints.

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Reliability Study on YangSaeng Survey Using by Hong-Cheon Data (홍천군 데이터를 이용한 한의학 설문지의 문항간 신뢰성 분석에 관한 연구)

  • Choo, Chae-Shin;Shin, Heon-Tae;Park, Hae-Mo;Lee, Sun-Dong;Jeon, Seong-Jin;Park, Chul-Soo
    • Journal of Society of Preventive Korean Medicine
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    • v.12 no.3
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    • pp.1-8
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    • 2008
  • Background : 'Yangsaeng' means health preservation concept in TKM(Traditional Korean Medicine). Health promotion using by traditional medicine was increased recently, but, has little measurement tools in evaluating traditional health care program. This study accomplished to analyze internal consistency reliability by Hong-Cheon survey data Method : Internal consistency reliability analysis within survey items Result : There was little reliability in mind and sexual life yangsaeng factor(Cronbach's alpha value 0.325, 0.273), higher reliability in lifestyle yangsaeng factor(0.718). And reliability was various within items according to age and health insurance type.

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