• 한국안전학회지
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• 제39권2호
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• pp.75-86
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• 2024

Hydrogen has been selected as one of the key technologies for reducing CO₂ emissions to achieve carbon neutrality by 2050. However, hydrogen safety issues should be fully guaranteed before the commercial and widespread utilization of hydrogen. Here, a bow-tie risk assessment is conducted for the hydrogen fuel supply system in a gas turbine power plant, which can be a mass consumption application of hydrogen. The bow-tie program is utilized for a qualitative risk assessment, allowing the analysis of the causes and consequences according to the stages of accidents. This study proposed an advanced bow-tie method, which includes the barrier criticality matrix and visualized maps of quantitative risk reduction. It is based on evaluating the importance of numerous barriers for the extent of their impact. In addition, it emphasizes the prioritization and concentrated management of high-importance barriers. The radar chart of a bow tie allows the visual comparison of risk levels before/after the application of barriers (safety measures). The risk reduction methods are semi-quantitatively analyzed utilizing the criticality matrix and radar chart, and risk factors from multiple aspects are derived. For establishing a secure hydrogen fuel storage system, the improvements suggested by the bow-tie risk assessment results, such as 'Ergonomic equipment design to prevent human error' and 'Emergency shutdown system,' will enhance the safety level. It attempts to contribute to the development and enhancement of an efficient safety management system by suggesting a method of calculating the importance of barriers based on the bow-tie risk assessment.

• 대한토목학회논문집
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• 제31권5D호
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• pp.679-687
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• 2011

시내버스 준공영제 시행이 시민들의 수송에 좋은 성과를 거두고 있지만 교통사망사고 증가에 따른 부작용이 발생하고 있다. 따라서 본 연구에서는 시내버스 준공영제 시행에 따른 교통사고 저감대책의 의사결정 모델 개발을 시도하였으며, 자료조사 및 분석방법은 교통전문가 설문과 계층분석법(AHP)을 활용하였다. 계층분석법(AHP)의 상위평가항목으로는 정량적 대책과 정성적 대책을 제시하였다. 하위평가항목 중 정량적 대책으로는 버스증차 및 안전장치 설치, 정류소 시설물 보완, 보행자 보호 시설물 보완, 교통안전 진단평가 및 보완으로 구성되어 있으며, 정성적 대책으로는 제도정비, 노선설계 보완, 교육 캠페인강화, 단속강화로 구성되었다. 분석결과를 살펴보면 첫째, 정성적 대책보다 정량적 대책에서 더 높은 가중치 결과가 나타났으며, 둘째, 정량적 대책으로는 정류소 시설물보완, 교통안전 진단평가 및 보완 순으로 나타났고, 셋째, 정성적 대책으로는 제도정비, 노선설계 보완 순으로 나타났다. 이런 결과는 향후 타시도의 교통사고 저감대책을 수립 시행할 경우 참고할 수 있는 기초 자료가 될 것이라고 사료된다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권10호
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• pp.4339-4345
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• 2015

Occupational exposure to wood dust is one cause of nasopharyngeal cancer (NPC); however, assessing this exposure remains problematic. Therefore, the objective of this study was to develop a semi-quantitative exposure assessment method and then utilize it to evaluate the association between occupational exposure to wood dust and the development of NPC. In addition, variations in risk by histology were examined. A case-control study was conducted with 327 newly diagnosed cases of NPC at the National Cancer Institute and regional cancer centers in Thailand with 1:1 controls matched for age, gender and geographical residence. Occupational information was obtained through personal interviews. The potential probability, frequency and intensity of exposure to wood dust were assessed on a job-by-job basis by experienced experts. Analysis was performed by conditional logistic regression and presented in odds ratio (ORs) estimates and 95% confidence intervals (CI). Overall, a non significant relationship between occupational wood dust exposure and NPC risk for all subjects was observed (ORs=1.61, 95%CI 0.99-2.59); however, the risk became significant when analyses focused on types 2 and 3 of NPC (ORs=1.62, 95%CI 1.03-2.74). The significant association was stronger for those exposed to wood dust for > 10 year (ORs=2.26, 95%CI 1.10-4.63), for those with first-time exposure at age > 25 year (ORs=2.07, 95%CI 1.08-3.94), and for those who had a high cumulative exposure (ORs=2.17, 95%CI 1.03-4.58) when compared with those considered unexposed. In conclusion, wood dust is likely to be associated with an increased risk of type 2 or 3 NPC in the Thai population. The results of this study show that semi-quantitative exposure assessment is suitable for occupational exposure assessment in a case control study and complements the information from self-reporting.

• 대한안전경영과학회지
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• 제8권6호
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• pp.13-27
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• 2006

The goal of this study is to propose the effective way of finding injurious factors and making improved plan that prevents the workers against musculoskeletal disorders at a semi-finished medical product fabricating company A questionnaire and an ergonomic assessment method were adopted to analyze the symptoms of workers' musculoskeletal disorders, and an analysis of working postures and a quantitative assessment on various processes were performed to find out harmful factors of workplace. Based on the result of the evaluation, to enhance the working environment, improvement of worktable, working space, tools, and outfit was suggested, and induction of mechanical system was also suggested. It can be concluded that the method and process described in this paper could be helpful for diagnosing the musculoskeletal disorders and making improvement plans to the company with similar working conditions and process.

• 한국안전학회지
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• 제33권6호
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• pp.37-41
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• 2018

Process safety technology has developed from qualitative methods such as HAZOP (hazard and operability study) to semi-quantitative methods such as LOPA (layer of protection analysis), and quantitative methods are actively studied these days. Quantitative risk assessment (QRA) is often based on fault tree analysis (FTA). FTA is efficient, but difficult to apply when failure events are not independent of each other. This problem can be avoided using a Markov process (MP). MP requires definition of all possible states, and thus, generally, is more complicated than FTA. A method is proposed in this work that uses an MP model and a Weibull distribution model in order to construct a reliability model for multiple dependent failures. As a case study, a pressure safety valve (PSV) is considered, for which there are three kinds of failure, i.e. open failure, close failure, and gas tight failure. According to recently reported inspection results, open failure and close failure are dependent on each other. A reliability model for a PSV group is proposed in this work that is to reproduce these results. It is expected that the application of the proposed method can be expanded to QRA of various systems that have partially dependent multiple failure states.

• Journal of Nutrition and Health
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• 제43권6호
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• pp.638-652
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• 2010

A valid food or dish frequency questionnaire needs to be developed in Korea for accurate dietary assessment because the dietary practices of Koreans are very different from those of other countries. This study was conducted to evaluate the accuracy of the newly developed, semi-quantitative, dish-based frequency questionnaire (Semi-DFQ) with 12-day dietary records (12-DRs) as a gold standard. The study subjects were 115 men and 173 women aged 30-65 years old. We calibrated the frequency, portion size and daily intake of 112 dish items reported in Semi-DFQ with those in 12-DRs by Spearman rank correlation coefficients (SCCs). The consumption frequency and portion size reported in Semi-DFQ were higher than those in 12-DRs. The SCCs for the consumption frequency of various dishes ranged from -0.07 (fried seaweed) to 0.70 (instant coffee), the portion size ranged from -0.09 (cold seaweed soup) to 0.68 (soju), and the daily intake ranged from -0.07 (fried seaweed) to 0.71 (soju). The SCCs were higher for dishes consumed daily, such as steamed rice,milk, coffee and alcohol, than those of foods eaten rarely. The overall agreements between the Semi-DFQ and 12-DRs were low for categories of consumption frequency and portion size, even though some dishes showed high SCCs. The SCCs of the two methods in consumption frequency and amount were higher among the women and younger subject. The results revealed the limitation of the Semi-DFQ for evaluating the status of usual individual intake. Therefore, the Semi-DFQ can be used in addition as dietary records and 24-hour recall depending on the research aims.

• Nutrition Research and Practice
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• 제4권2호
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• pp.142-148
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• 2010

The food frequency questionnaire (FFQ) has been used as an important dietary assessment tool in epidemiologic studies, but the usefulness of the FFQ has been debated in recent years. This study was performed to evaluate the relative validities of 3-day food records and the semi-quantitative FFQ. A total of 124 subjects finished 3-day food records (FRs) during each of the four seasons, as well as the FFQ from December 2002 to May 2004. The FFQ was a food based semi-quantitative FFQ including 103 items. Three-day FRs from each season and a randomly selected season were compared with the remaining 9-day FRs. The remaining 9-day FRs, as a reference measurement, were also compared with the FFQ. Pearson's correlation coefficients between the 3-day FRs and the 9-day FRs were between 0.14 and 0.56. Pearson's correlation coefficients between the FFQ and the 9-day FRs ranged between 0.07 and 0.41. Average proportions of classification into the same quartiles, adjacent quartiles, and distant quartiles between the 3-day FRs and the 9-day FRs were 35.8%, 40.5%, and 5.2%, respectively. On average, the proportions of classification into the same quartiles, adjacent quartiles, and distant quartiles between the FFQ and the 9-day FRs were 31.1%, 39.4%, and 6.9%, respectively. Three-day FRs showed higher correlations and higher agreement proportions of quartile classification with the 9-day FRs than did the FFQ, but both relative validities of 3-day FRs and the FFQ appear to be acceptable as dietary assessment tools. Further studies for validating food intake by reliable biomarkers are necessary.

• 대한기계학회논문집A
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• 제29권10호
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• pp.1392-1398
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• 2005

API 581 guideline provides a methodology for calculating the risks of equipments in refinery or petrochemical plant. However, especially in part of the consequence of failure, there is a major limitation of its application to the petrochemical plant directly since only a representative material is considered in calculating the risk while the equipment is composed of numerous materials. The objectives of this paper are to propose an enhanced risk-based inspection (RBI) technique to resolve shortcomings inclusive of the above issue and to assess the risks of typical petrochemical equipments. In this respect, a program incorporating material database was developed to fully incorporate the characteristics of different materials. The proposed RBI program consists of qualitative, semi-quantitative and quantitative risk evaluation modules in which toxic materials as well as representative materials were selected automatically for comparison to those in the current guideline. It has been applied to assess the risks of equipments in ethylene facilities of petrochemical plants. Thereby, more realistic evaluation results were obtained and applicability of the proposed RBI program was proven.

• 한국해양학회지:바다
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• 제29권2호
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• pp.116-138
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• 2024

본 연구는 '해양교란유해종'이 해양 환경과 사회경제적 측면에 미치는 영향을 평가하기 위한 새로운 도구와 프로토콜을 제시한다. 한국의 해양생태계 보전 및 관리법에서 발견된 한계점을 보완하기 위해, 본 연구는 해양 환경과 사회경제 그룹(영역)으로 나누어진 영향 평가 프레임워크를 도입하였다. 각 그룹은 6개의 영향 평가 카테고리(범주)로 구성되어 있으며, 준정량적인 5단계 척도를 사용하여 생태계의 교란에서 건강과 재산에 대한 영향에 이르는 폭넓은 이슈들을 다루는 유연한 방식을 제공한다. 이 영향평가 도구의 실행은 델파이 방법을 기반으로 한 체계적인 5단계 프로세스를 통해 진행된다. 이 접근법은 다양한 전문가와 이해관계자 간의 협력을 촉진하며, 다양한 관점을 통합하는 포괄적인 평가를 가능하게 한다. 또한 이 연구는 불확실성을 효과적으로 관리하고 결과의 일관성을 향상시키는 전략도 모색되었다. 본 평가 프로토콜의 적용은 '해양교란유해종'에 의한 생태학적 피해의 정도를 계량화하고 관리 대상 및 예방 조치의 우선순위를 정립하는 데 결정적인 역할을 할 것으로 기대된다. 평가 과정의 궁극적인 목표는 의사결정자가 해양생태계 보전과 사회경제적 영향을 완화하기 위한 전략을 수립하도록 지원하는 것이다.

• Nutritional Sciences
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• 제6권3호
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• pp.173-184
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• 2003

Objective : This study was carried out to develop a semi-quantitative food frequency Questionnaire (SQFFQ) for estimating average dietary intake to determine the risk factor for lifestyle-related diseases in a conjoint cohort study. Design : We developed an SQFFQ for genomic epidemiological studies based on the data in the'98 Korea Health and Nutrition Examination Survey. A subset of data on informative food items was collected using the 24-hr recall method with 2,714 adults aged 40 or older living in middle-sized cities or in rural areas in Korea. The cumulative percent contribution and cumulative multiple regression coefficients of 17 nutrients (energy, fat, carbohydrate, protein, fiber, iron, potassium, sodium, calcium, phosphorus, vitamin A, retinol, $\beta$-carotene, vitamin $B_1$, vitamin $B_2$, niacin and vitamin C) of each food were computed. Results : Two hundred and forty-nine foods, which were selected based on their 0.9 cumulative percent contribution, and 254 foods, which were selected based on their 0.9 cumulative multiple regression coefficients, respectively, were grouped into 97 food groups according to their nutrient contents. Several popular Korean foods, which were missing from the list due to the seasonality of the survey, were included. The portion sizes were derived from the same data set. The SQFFQ covered 84.8 percent of the intake of 17 nutrients in the one day diet record data of our 326 cohort study subjects. Conclusions . The final list included 103 food items. The foods list in the SQFFQ described herein accounted for 84.8 percent of the average intake of 17 nutrients. Therefore, the list could be used for the assessment of the baseline dietary intakes of the conjoint cohort studies.