• Title/Summary/Keyword: reliability and safety

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Repeat Auditing of Primary Health-care Facilities Against Standards for Occupational Health and Infection Control: A Study of Compliance and Reliability

  • Cloete, Brynt;Yassi, Annalee;Ehrlich, Rodney
    • Safety and Health at Work
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    • v.11 no.1
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    • pp.10-18
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    • 2020
  • Background: The elevated risk of occupational infection such as tuberculosis among health workers in many countries raises the question of whether the quality of occupational health and safety (OHS) and infection prevention and control (IPC) can be improved by auditing. The objectives of this study were to measure (1) audited compliance of primary health-care facilities in South Africa with national standards for OHS and IPC, (2) change in compliance at reaudit three years after baseline, and (3) the inter-rater reliability of the audit. Methods: The study analyzed audits of 60 primary health-care facilities in the Western Cape Province of South Africa. Baseline external audits in the time period 2011-2012 were compared with follow-up internal audits in 2014-2015. Audits at 25 facilities that had both internal and external audits conducted in 2014/2015 were used to measure reliability. Results: At baseline, 25% of 60 facilities were "noncompliant" (audit score<50%), 48% "conditionally compliant" (score >50 < 80%), and only 27% "compliant" (score >80%). Overall, there was no significant improvement in compliance three years after baseline. Percentage agreement on specific items between internal and external audits ranged from 28% to 92% and kappa from -0.8 to 0.41 (poor to moderate). Conclusion: Low baseline compliance with OHS-IPC measures and lack of improvement over three years reflect the difficulties of quality improvement in these domains. Low inter-rater reliability of the audit instrument undermines the audit process. Evidence-based investment of effort is required if repeat auditing is to contribute to occupational risk reduction for health workers.

Improvement Strategy of System Unavailability by Review of Logical Structure and Reliability Importance of Reliability Block Diagram (RED) and Fault Tree Analysis (FTA) (RBD와 FTA의 논리구조와 신뢰성 중요도의 고찰에 의한 시스템 비시간가동률 개선방안)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.13 no.3
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    • pp.45-53
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    • 2011
  • The research proposes seven elimination rules of redundant gates and blocks in Fault Tree Analysis (FTA) and Reliability Block Diagram (RBD). The computational complexity of cut sets and path sets is NP-hard. In order to reduce the complexity of Minimal Cut Set (MCS) and Minimal Path Set (MPS), the paper classifies generation algorithms. Moreover, the study develops six implementation steps which reflect structural importance (SI) and reliability importance (RI) from Reliability Centered Maintenance (RCM) that a priority of using the functional logic among components is to reduce (improve) the system unavailability (or availability). The proposed steps include efficient generation of state structure function by Rare Event Enumeration (REA). Effective use of importance measures, such as SI and ill measures, is presented based on the number and the size of MCS and MPS which is generated from the reference[5] of this paper. In addition, numerical examples are presented for practitioners to obtain the comprehensive understanding of six steps that is proposed in this research.

The Effect of Food Service Franchise Selection Factors on Brand Loyalty and Revisit Intention - Focusing on Consumer Survey in Tokyo - (외식 프랜차이즈 선택요인이 브랜드 충성도와 재방문의도에 미치는 영향 연구 -동경(東京)지역 한국 외식 프랜차이즈를 이용하는 소비자 설문조사를 중심으로-)

  • Kim, Seon-Hyen;Hwang, Jae-Hyun
    • Korean Journal of Organic Agriculture
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    • v.25 no.4
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    • pp.663-677
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    • 2017
  • As Korean food service franchise companies sought to advance into around 2,000 new foreign markets, the importance of global management was emphasized. They intensively expanded into Chinese and American markets in 2015 and these two markets account for approximately 40% of total food service franchise companies in foreign countries. Although Japan has huge franchise market, Korean food service franchise companies in Japan only account for 5% of total franchise companies in Asian countries. The purpose of this study is to analyze the relationship between food service franchise selection factors, brand loyalty, and revisit intention of Japanese consumers using Korean food service franchise companies in Japanese food service market, and based on the analysis results, draw the implications for the expansion of Korean food service franchise companies into the Japanese market. Food service franchise selection factors is defined as service and cleanliness, taste, safety and reliability, cost and convenience, and professionalism. The study results can be summarized as follows. First, analysis was performed to identify the effects of food service franchise selection factors on the brand loyalty, it showed that five food service franchise selection factors including professionalism, service and cleanliness, cost and convenience had positive (+) effects on the brand loyalty. One of the most important factors influencing the brand loyalty is professionalism. In order to raise food service franchise's professionalism, it is necessary for the food service franchise companies to establish stronger strategies containing professional operation systems and services compared to general restaurants. Second, analysis was performed to identify the effects of food service franchise selection factors on revisit intention, five food service franchise selection factors, service and cleanliness, safety and reliability, and cost and convenience had positive (+) effects on revisit intention. One of the most important factors influencing revisit intention is safety and reliability. Thus, in order to raise safety and reliability it is important to form trust with consumers by properly utilizing systems of food hygiene and food safety accreditation.

Study on the Optimum Route Travel Time for Bus to Improve Bus Schedule Reliability (정시성 확보를 위한 버스노선 당 적정 운행시간 산정 연구)

  • Kim, Min ju;Lee, Young ihn
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.6
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    • pp.112-123
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    • 2017
  • The accurate forecasting of the public transportation's transit and arrival time has become increasingly important as more people use buses and subways instead of personal vehicles under the government's public transportation promotion policy. Using bus management system (BMS) data, which provide information on the real-time bus location, operation interval, and operation history, it is now possible to analyze the bus schedule reliability. However, the punctuality should always be considered together with the operation safety. Therefore, this study suggests a new methodology to secure both reliability and safety using the BMS data. Unlike other studies, we calculated the bus travel time between two bus stops by dividing the total travel length into 6 sections using 5 different measuring points. In addition, the optimal travel time for each bus route was proposed by analyzing the mean, standard deviation and coefficient of variation of the each section's measurement. This will ensure the reliability, safety and mobility of the bus operation.

Methodology for Reliability-based Assessment of Capacity-Rating of Plate Girder Railroad Bridges using Ambient Measurement Data (상시 계측 데이터를 이용한 신뢰성에 기초한 판형 철도교의 내하력 평가법)

  • Cho, Hyo Nam;Choi, Hyun Ho;Lee, Sang Yoon;Sun, Jong Wan
    • Journal of Korean Society of Steel Construction
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    • v.15 no.2
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    • pp.187-196
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    • 2003
  • Today, the Working Stress Rating (WSR) is being widely used for the capacity-rating and the safety assessment of railroad steel bridges. Since it cannot incorporate the uncertainties, several studies have been carried out in order to get over the incompleteness of the conventional capacity-rating and safety assessment. A system reliability-based equivalent capacity-rating method, which can evaluate the capacity of existing bridges, has been recently proposed. For more efficient reliability analysis, probabilistic parameters of the random variables in the limit-state models should be reasonably evaluated. Especially, uncertainties for live load effects must be realistically included. In this study, an improved limit-state model was used for the system reliability-based equivalent strength method. This model can incorporate the probabilistic parameters obtained from ambient measurement data. To demonstrate the applicability of the improved system reliability-based equivalent capacity rating method, this was applied to the existing steel plate girder bridge for comparison with the conventional capacity-rating and safety assessment.

Human Reliability Analysis Using Reliability Physics Models (신뢰도 물리모델을 이용한 인간신뢰도분석 연구)

  • Moo-sung Jae
    • Journal of the Korean Society of Safety
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    • v.17 no.3
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    • pp.123-130
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    • 2002
  • This paper presents a new dynamic human reliability analysis method and its application for quantifying the human error probabilities in implementing accident management actions. The action associated with implementation of the cavity flooding during a station blackout sequence is considered for its application. This method is based on the concept of the quantified correlation between the performance requirement and performance achievement. For comparisons of current HRA methods with the new method, the characteristics of THERP, HCR, and SLIM-MAUD, which m most frequency used method in PSAs, are discussed. The MAAP code and Latin Hypercube sampling technique are used to determine the uncertainty of the performance achievement parameter. Meanwhile, the value of the performance requirement parameter is obtained from interviews. Based on these stochastic obtained, human error probabilities are calculated with respect to the various means and variances of the things. It is shown that this method is very flexible in that it can be applied to any kind of the operator actions, including the actions associated with the implementation of accident management strategies.

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.

Evaluation of Target Failure Level on Sliding Mode of Vertical Breakwaters using Safety Factors (안전율을 이용한 직립 방파제의 활동에 대한 목표파괴수준 산정)

  • Lee, Cheol-Eung
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.2
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    • pp.112-119
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    • 2010
  • A Monte-Carlo simulation method is proposed which can evaluate the target failure/safety levels on any failure modes of harbor structures as a function of central safety factor. Unlike the calibration method based on the average safety level of conventional design criteria, the target failure/safety level can be directly evaluated by only using central safety factors of the harbor structures which have been designed by safety factor method during the past several decade years. Several mathematical relationships are represented to straightforwardly connect the conventional safety factor design method with reliability-based design method. Even though limited data have been used in applying Monte-Carlo simulation method to sliding failure mode of the vertical breakwaters, it is found that target reliability indices evaluated by the suggested method in this paper is satisfactorily agreement with new criteria of reliability index of Japan.

Study of Standardization and Test Certification for Wearable Smart Devices (웨어러블 스마트기기의 표준화 및 시험인증 연구)

  • Han, Tae-Su;Kim, Deok-kee;Kwon, Oh-Young;Choa, Sung-Hoon
    • Journal of the Microelectronics and Packaging Society
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    • v.23 no.4
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    • pp.11-18
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    • 2016
  • Today, wearable technology products are used in a wide range of consumer, healthcare, bio-medical, and industrial applications. The market for wearable technology products is expected to increase dramatically over the next several years. In addition, concerns for safety, performance and reliability of wearable products keep increasing and will be essential for widespread acceptance in the marketplace. Wearable smart devices, which are generally in contact with the human body and skin, are exposed to the risk of the electric shock, burn, and explosion. Therefore, the standardization of wearable devices in terms of human safety and reliability should be very important. Furthermore, the development of test method and test certification of the wearable products will be one of the key technology for mass production. Such standardization and certification will help consumers to choose the safest and best quality wearable devices and allow manufacturers to prove the safety and quality of their products, thereby helping them to gain a competitive technology. This paper discusses the current status of the wearable smart devices as well as the standardization and test certification applicable to wearable technology products.