• Title/Summary/Keyword: reliability and safety

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Validity Assessment of the Persian Version of the Nordic Safety Climate Questionnaire (NOSACQ-50): A Case Study in a Steel Company

  • Yousefi, Yadolah;Jahangiri, Mehdi;Choobineh, Alireza;Tabatabaei, Hamidreza;Keshavarzi, Sareh;Shams, Ali;Mohammadi, Younes
    • Safety and Health at Work
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    • v.7 no.4
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    • pp.326-330
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    • 2016
  • Background: The Nordic Safety Climate Questionnaire-50 (NOSACQ-50) was developed by a team of Nordic occupational safety researchers based on safety climate and psychological theories. The aim of this study was to develop and validate the Persian version of NOSACQ-50 and assess the score of safety climate on a group of workers in a steel company in Iran. Methods: The Persian version of NOSACQ-50 was distributed among 661 employees of a steel company in Qazvin Province (Iran). Exploratory factor analysis (EFA) and confirmatory factor analysis were used to determine the dimensions of the questionnaire. The reliability of the questionnaire was assessed using Cronbach ${\alpha}$ coefficient. Pearson correlation test was applied to investigate the correlation between different dimensions. Results: The results of EFA showed that the Persian version of NOSACQ-50 consisted of six dimensions. The Cronbach ${\alpha}$ coefficient of the questionnaire was 0.94. The mean score of safety climate in all dimensions was 2.89 (standard deviation 0.60). Conclusion: The Persian version of NOSACQ-50 had a satisfactory validity for measuring safety climate in the studied Iranian population.

The Third Version of the Copenhagen Psychosocial Questionnaire

  • Burr, Hermann;Berthelsen, Hanne;Moncada, Salvador;Nubling, Matthias;Dupret, Emilie;Demiral, Yucel;Oudyk, John;Kristensen, Tage S.;Llorens, Clara;Navarro, Albert;Lincke, Hans-Joachim;Bocerean, Christine;Sahan, Ceyda;Smith, Peter;Pohrt, Anne
    • Safety and Health at Work
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    • v.10 no.4
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    • pp.482-503
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    • 2019
  • Introduction: A new third version of the Copenhagen Psychosocial Questionnaire (COPSOQ III) has been developed in response to trends in working life, theoretical concepts, and international experience. A key component of the COPSOQ III is a defined set of mandatory core items to be included in national short, middle, and long versions of the questionnaire. The aim of the present article is to present and test the reliability of the new international middle version of the COPSOQ III. Methods: The questionnaire was tested among 23,361 employees during 2016-2017 in Canada, Spain, France, Germany, Sweden, and Turkey. A total of 26 dimensions (measured through scales or single items) of the middle version and two from the long version were tested. Psychometric properties of the dimensions were assessed regarding reliability (Cronbach α), ceiling and floor effects (fractions with extreme answers), and distinctiveness (correlations with other dimensions). Results: Most international middle dimensions had satisfactory reliability in most countries, though some ceiling and floor effects were present. Dimensions with missing values were rare. Most dimensions had low to medium intercorrelations. Conclusions: The COPSOQ III offers reliable and distinct measures of a wide range of psychosocial dimensions of modern working life in different countries; although a few measures could be improved. Future testing should focus on validation of the COPSOQ items and dimensions using both qualitative and quantitative approaches. Such investigations would enhance the basis for recommendations using the COPSOQ III.

Analysis of Live Load Factor for Bridge Evaluation Through Reliability Based Load Factor Calibration (신뢰도기반 하중계수 캘리브레이션을 통한 교량 평가 활하중계수 분석)

  • Yoo, Min-Sun;Kim, Kyung-Hyun;Paik, In-Yeol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.6
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    • pp.212-221
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    • 2022
  • In this paper, the evaluation procedure applying the limit state design method is studied to be consistent with the newly issued bridge design code in Korea. The live load factor for evaluation is proposed by calibrating for the target reliability index through reliability analysis. Using the actual bridge information collected for the representative bridge types in Korea, the load effects of the design live loads for the previous and current design codes are calculated and compared. The live load factor is calibrated through reliability analysis using the minimum required strength which equals to the load effect obtained for the example bridge. Bridge evaluation is performed by applying the live load factors for the evaluation level as well as design level. The load rating result is generally increased by applying the limit state design method compared to the previous design method and applying the proposed load factor for lowered target reliability index further increased the rating result.

Safety analysis and deterioration evaluation of water pipe for improvement according to service year (상수도관의 개량을 위한 시간에 따른 노후도 및 안전성 분석)

  • Kwon, Hyuk Jae;Lee, Kyung Je
    • Journal of Korea Water Resources Association
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    • v.54 no.8
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    • pp.589-597
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    • 2021
  • In this study, corrosion depth equation was suggested according to real measured corrosion data, and then management indexes of pipe network which can determine the deterioration rate and safety rate has been established and applied to real pipe networks. Furthermore, reliability analysis and management index analysis have been conducted to estimate and compare the deterioration rate. From the results of reliability analysis, it was found that probability of failure of 200 mm steel pipe can be increased from 4.36% at present time to 8.23% after 20years at Gaduk and from 7.35% to 12.99% at Nami. From the results of management index analysis, it was found that deterioration rates of Gaduk and Nami are 1.009 and 1.174, respectively. Priority of improvement and replacement of water pipe can be determined by results of reliability analysis and management index analysis.

A Study on the Development of Installation and Management of Safety Shower (Safety shower 설치 및 관리기준 개선에 관한 연구)

  • Lee, Dong Hyeok;Yoo, Byung Tae
    • Journal of the Korean Institute of Gas
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    • v.22 no.6
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    • pp.1-7
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    • 2018
  • Currently chemical plant risk have been issued by occurring frequent accidents. Accidents can be generally composed of fire, explosion, release in chemical plant. In case of fire and explosion, accident victims are occurred immediately after accident but release accident, late emergency response cause damage to worker. Especially, there are many victims by late emergency response against chemical exposure to skin. In case of chemical exposure to skin, irreversible damage like death, blindness, burn can be prevented by washing immediately. Safety shower can provide the cleaning for chemical exposure to eye, skin. Most of chemical plants are built in 1980s so equipment become superannuated. In this reason, safety shower also cannot operate normally in emergency situation. Therefor safety shower should be managed by installation and management guideline. This study perform the establishment guideline for safety shower installation and inspection to increase the reliability.

Target Reliability Indices of Static Design Methods for Driven Steel Pipe Piles in Korea (국내 항타강관말뚝 설계법의 목표 신뢰도지수)

  • Kwak, Kiseok;Huh, Jungwon;Kim, Kyung Jun;Park, Jae Hyun;Lee, Juhyung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1C
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    • pp.19-29
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    • 2008
  • As a part of study to develop LRFD (Load and Resistance Factor Design) codes for foundation structures in Korea, reliability analyses for driven steel pipe piles are performed and the target reliability indices are selected carefully. The 58 data sets of static load tests and soil property tests conducted in the whole domestic area were collected and analyzed to determine the representative bearing capacities of the piles. The static bearing capacity formula and the Meyerhof method using N values are applied to calculate the expected design bearing capacity of the piles. The resistance bias factors were evaluated for the two static design methods by comparing the representative bearing capacities with the design values. Reliability analysis was performed by two types of advanced methods: First Order Reliability Method (FORM), and Monte Carlo Simulation (MCS) method using resistance bias factor statistics. The static bearing capacity formula exhibited relatively small variation, whereas the Meyerhof method showed relatively high inherent conservatism in the resistance bias factors. Reliability indices for safety factors in the range of 3 to 5 were evaluated respectively as 1.50~2.89 and 1.61~2.72 for both of the static bearing capacity formula and the Meyerhof method. The target reliability indices are selected as 2.0 and 2.33 for group pile case and 2.5 for single pile case, based on the reliability level of the current design practice and considering redundancy of pile group, acceptable risk level, construction quality control, and significance of individual structure.

The Prediction of Failure Probability of Bridges using Monte Carlo Simulation and Lifetime Functions (몬테칼로법과 생애함수를 이용한 교량의 파괴확률예측)

  • Seung-Ie Yang
    • Journal of the Korean Society of Safety
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    • v.18 no.1
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    • pp.116-122
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    • 2003
  • Monte Carlo method is one of the powerful engineering tools especially to solve the complex non-linear problems. The Monte Carlo method gives approximate solution to a variety of mathematical problems by performing statistical sampling experiments on a computer. One of the methods to predict the time dependent failure probability of one of the bridge components or the bridge system is a lifetime function. In this paper, FORTRAN program is developed to predict the failure probability of bridge components or bridge system by using both system reliability and lifetime function. Monte Carlo method is used to generate the parameters of the lifetime function. As a case study, the program is applied to the concrete-steel bridge to predict the failure probability.

Reliability estimation about quality assurance method of radiotherapy planning (방사선치료계획 정도관리 방법에 따른 신뢰도 평가)

  • Kim, Jeong-Ho;Kim, Gha-Jung;Yoo, Se-Jong;Kim, Ki-Jin
    • Journal of the Korea Safety Management & Science
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    • v.17 no.1
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    • pp.119-124
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    • 2015
  • According as radiation therapy technique develops, standardization of radiation therapy has been complicated by the plan QA(Quality Assurance). However, plan QA tools are two type, OADT (opposite accumulation dose tool) and 3DADT (3 dimensional accumulation dose tool). OADT is not applied to evaluation of beam path. Therefore tolerance error of beam path will establish measurement value at OADT. Plan is six beam path, five irradiation field at each beam path. And beam path error is 0 degree, 0.2 degree, 0.4 degree, 0.6 degree, 0.6 degree, 0.8 degree. Plan QA accomplishes at OADT, 3DADT. The more path error increases, the more plan QA error increases. Tolerance error of OADT path is 0.357 using tolerance error of conventional plan QA. Henceforth plan QA using OADT will include beam path error. In addition, It will increase reliability through precise and various plan technique.

Development of the Skin Treatment Unit using Low Temperature Plasma (저온 플라즈마를 이용한 피부치료기 개발에 관한 연구)

  • Song, Kwang-Hyun;Ko, Yon-Seok;Lee, Woo-Cheol
    • The Journal of the Korea institute of electronic communication sciences
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    • v.9 no.12
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    • pp.1427-1434
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    • 2014
  • Among the medical devices, medical treatments inflicting physical energy from the outside of the body to the inside or using the energy from the devices which take advantages of chemical changes of the human body require a high degree of reliability and safety. In particular, the medical treatment on the most exposed skin to the external surface in all parts of the human body will be very important. In this perspective, when you undergo skin treatment, you need to reduce all risks and to maximize the effect of treatment equipment. Therefore, the development of equipment which guarantees high therapeutic efficacy and safety is essential.

A Study on the Service Quality Evaluation of University Administrations - The utilization of DMAIC process 6sigma - (대학행정 서비스품질 평가 연구 - 6시그마 DMAIC 프로세스 이용 -)

  • Koo, Il-Seob;Cho, In-Hee;Jung, Kyung-Hee
    • Journal of the Korea Safety Management & Science
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    • v.10 no.4
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    • pp.209-218
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    • 2008
  • The growth in services has focused issues of service quality both for commercial enterprises and across a range of public services and government institutions. The education sector, in particular, has undergone radical change to meet the needs of its varied constituents. This paper examines key issues in internal service, customer satisfaction, service quality, relational commitment as they apply in one particular education sector. The purpose of this study is to analyze effect of internal service on customer satisfaction, educational service quality. First, In the dimension of internal service, many factors affect internal customer's evaluation for overall satisfaction. They are categorized as five factors; tangibles, reliability, responsiveness, assurance, empathy. The results of this study supported the proposed conceptual framework overall. Therefore, we identified that internal service quality is the antecedent of an internal customer satisfaction, and the consequent variables of an internal customer satisfaction are educational service quality, external customer satisfaction. The major findings of this study are summarized as follows. First, some factors(tangibles, reliability, responsiveness, assurance, empathy) affected positively internal customer satisfaction. Second, external service quality affected positively educational service quality, external satisfaction. In other words, the more internal customers have experienced internal service, the higher internal service quality deliver educational service quality.