• 대한안전경영과학회지
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• 제8권2호
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• pp.25-38
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• 2006

It was investigated the current state of work-related musculoskeletal disorders (WMSDs), which is one of the major problems in occupational safety and health management. A survey was conducted for safety personnel serve in the enterprises located at two cities in Gyungbuk area, Gumi and Pohang where the major industrial complex reside. The goal of this study was to identify whether the category and scale of the enterprises affect the sort of hazard factors, occurrence rate, and countermeasures against WMSDs. The results from the survey indicated that there were significant differences in the level of recognition and counteracts for WMSDs among the enterprises subject to their categories and scales. On the basis of these results, it was considered a more efficient way of spreading proper ergonomic knowledge and skills to the industries that were coincided with the circumstances of individual enterprise.

• East Asian Economic Review
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• 제26권2호
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• pp.95-117
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• 2022

This paper empirically examines what factors affected the termination of anti-dumping measures in Korea during the 2006-2019 period. Employing a meticulous literature review, the paper investigates the WTO's and Korea's rules on the termination of anti-dumping measures and sets up the related variables in the Cox proportional hazards model. The empirical results show that the GDP growth rate, employment, and trade competitiveness in domestic industries had positive effects on the hazard of the termination of AD measures, while free trade agreements had negative effects. By industry, the hazard of the termination of AD measures was less prominent in the steel industry, while it was more prominent in the machinery industry. These results imply that AD measures in Korea had the properties of a proper trade remedy policy and, at the same time, a protectionism tool to sustain its domestic industries, depending on industrial characteristics and other trade policies.

• 한국환경보건학회지
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• 제44권4호
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• pp.340-347
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• 2018

Objectives: This study was performed to determine environmental hazard factors and provide more eco-friendly child activity spaces within children's playgrounds installed in Gyeonggi-do Province. Methods: Basic (XRF) and precise (ICP, UV) inspections were conducted. The test items examined were heavy metals and parasite eggs. As a sampling point, painted finish materials (180), synthetic rubber (50), and sand (50) were selected. Results: The total excess rate of heavy metals in the XRF was found to be 7.4% (17/230 points). In a comparison between the basic and precise inspections with 17 excess points, the concentration deviation between the two tests was found to be from 0.01 to 7.7 times, resulting in a large difference. Furthermore, all the excess samples were dual samples. However, the contribution rates of Pb and $Cr^{6+}$ to combined concentration were found to be 85.1 and 14.9% for basic inspection and 91.9 and 8.1% for precise inspections, so there is a similar tendency between the two tests. The excess rate of parasite eggs in sand was expressed at 6%. The excess rate of heavy metals in synthetic rubber was found to be 0%. Conclusion: The reliability of the XRF is low. However, considering the contribution rate of Pb and $Cr^{6+}$ between the two tests, it is likely to be applicable for screening. Dual samples provided high concentrations and excess samples and care should be taken when managing them.

• 품질경영학회지
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• 제25권3호
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• pp.96-107
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• 1997

The recent stream to reliability prediction is that it is totally inclusive in depth to consider even the operating and environmental condition at the level of finished goods as well as component itselves. In this study, firstly we present the reliability prediction methods by entire failure rate model which failure rate at the system level is added to the failure rate model at the component level. Secondly we build up the improved bases of reliability demonstration through a, pp.ication of Kaplan-Meier, Cumulative hazard, Johnson's methods as non-parametric and Maximum Likelihood Estimator under exponential & Weibull distribution as parametric. And also present the methods of curve fitting to piecewise failure rate under Weibull distribution, PRST (Probability Ratio Sequential Test), curve fitting to S-shaped reliability growth curve, computer programs of each methods. Lastly we show the practical for determination of optimal burn-in time as a method of reliability enhancement, and also verify the practical usefulness of the above study through the a, pp.ication of failure and test data during 1 year.

• Corrosion Science and Technology
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• 제4권5호
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• pp.201-206
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• 2005

Starting with the meaning of the word quality, diverse concepts connoted by the term are examined. Instead of a bathtub curve, the desirable shape of a failure rate covering the entire life of a good product, which might be called hockey-stick line, is introduced. From the hockey-stick line and the definition of reliability, two measurements are extracted. The terms r-reliability (failure rate) and durability (product life) are explained. The conceptual analysis of failure mechanics explains that reliability technology pertains to design area. The desirable shape of hazard rate curve of electronic items, hockey-stick line, clarifies that Mean-Time-to-failure (MTTF) as the inverse of failure rate can be regarded a nominal life. And Bx life, different from MTTF, is explained. Reliability relationships between components and set products are explained. Reshaped definitions of r-reliability and durability are recommended. The procedure to improve reliability and the reasons for failing to identify failure mode are clarified in order to search right solutions. And generalized Life-Stress failure model is recommended for the calculation of acceleration factor.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.206-212
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• 2009

Chemical behaviors of each surface material for interior facilities affect to fire initiation and growth in general fire situation. These chemical behaviors were characterized by thermal properties (Heat release rate, Pyrolysis rate, specific heat, etc) which could be derived from experimental test. Especially, Heat release rate which indicates aspect of fire size is one of the most important property to asses fire hazard and protection needs. The cone calorimeter test (ISO 5660) has recently assumed to a dominant role in bench scale fire testing to obtain the Heat release rate of materials. This value could be calculated by the 'Oxygen Consumption Method' under various producing irradiances to each surface of materials. In this study, Process of the cone calorimeter test was simulated by Pyrolysis model of FDS (Fire Dynamics Simulator by NIST) base on the ISO 5660 international standard. Then, we could estimate the simulation method of FDS in case of single materials through the comparative study with test results.

• 지질공학
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• 제19권3호
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• pp.295-306
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• 2009

본 연구는 지하수, 토양, 대기의 노출경로에 따라서 부산광역시 사상공단의 지하수와 토양이 인체와 환경에 미치는 영향을 평가하였다. 토양과 대기의 노출경로에 따른 발암 위해는 나타나지 않았으나, 지하수에서는 TCE와 PCE의 발암 위해성이 각각의 기준 한계값인 1.0E-6과 1.0E-5에 대해서 각각 6.7E-6과 1.0E-5로 나타나 발암 위해가 있는 것으로 판단되었다. 대기에서는 비발암성 위해가 나타나지 않았다. 토양의 위해계수와 위해지수는 각각 3.4E-5와 5E-5로서 기준 한계값(1.0) 보다 낮게 나타났으나, 지하수의 위해계수와 위해지수는 각각 0.7 (위해성이 없음)과 1.4(위해성이 있음)로 나타났다. TCE의 최소성분감소비(CRF)는 2.5로서 TCE의 정화작업이 요구된다. 18개의 노출인자에 대한 민감도 분석 결과, 8개의 노출 인자(비 발암 물질에 대한 평균 수명, 발암 물질에 대한 평균 수명, 체중, 노출기간, 노출빈도, 피부노출빈도, 토양 섭취율, 물 섭취율)의 변화에 따라서 위해도가 변화하는 것으로 나타났다.

• 약학회지
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• 제57권1호
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• pp.8-17
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• 2013

The objective of this study is investigation of contamination levels and transfer rate of heavy metals and assessment of health risk effects in animal medicines. A total of sixteen items with 148 samples were obtained for this investigation from major herbal medicine producing areas and herbal markets from 2011 to 2012. Inductively coupled plasma mass spectrometer method was conducted for the quantitative analysis of Pb, Cd and As. In addition, the mercury analyzer system was conducted for that of Hg without sample digestion. The average contents of heavy metals in animal medicines were as follows : 1.55 mg/kg for Pb, 0.28 mg/kg for Cd, 0.70 mg/kg for As and 0.047 mg/kg for Hg respectively. The average contents of heavy metals in decoctions were as follows : 0.03 mg/kg for Pb, 0.01 mg/kg for Cd, 0.17 mg/kg for As and 0.003 mg/kg for Hg respectively. The average transfer rates of heavy metals from animal medicines to decoctions were 1.9% for Pb, 3.6% for Cd, 24.2% for As and 6.0% for Hg respectively. Cancer risks of animal medicines and decoctions through slope factor by ministry of environment republic korea and environmental protection agency was $1.36{\times}10^{-6}$ and $2.50{\times}10^{-8}$ for Pb and $7.46{\times}10^{-5}$ and $1.98{\times}10^{-5}$ for As (assuming that the total arsenic content was equal to the inorganic arsenic) respectively. The hazard index of heavy metals in animal medicines and decoctions was below recommended hazard index as 0.52 and 0.05 respectively. Taken together, cancer risks about Pb and hazard indexes of animal medicines and decoctions indicate that the majority of samples except for some samples with relative high contents of heavy metals were safe. But cancer risks about As of animal medicines indicate that the majority of samples were not relatively safe.

• 한국방재학회 논문집
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• 제9권4호
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• pp.107-113
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• 2009

본 연구는 점착성 미립자의 침전률에 대한 플록의 영향에 관한 것이다. 연구 진행시 플록 밀도와 입경변화의 영향도 고려하였다. 플록입자의 침전속도는 정지수면에서 측정되었다. 플록 입경과 밀도는 수정된 Stokes방정식에 유체의 밀도, 입자의 밀도, 점성계수 및 측정된 침전속도와 입경과의 관계식으로부터 얻은 플록 차원을 이용하여 분석되었다. 석영과 알루미나의 플록지름은 초기농도가 증가함에 따라 증가되었으며, 염도농도의 증가에 따른 석영의 플록된 입경은 $0.8{\sim}10$ ${\mu}m$이다. 플록밀도는 입경이 증가함에 따라 감소하였다. 플록 침전속도와 입경의 관계는 로그표위에 직선식으로 표현된다. 플록 차원($=n_f$)은 초기농도가 증가할 경우 2.65이며, 염도가 증가할 때 2.93이다. 침전속도를 예측하기 위한 비례상수(n)는 제시되었으며, 그 범위는 $1{\sim}1.93$이다.

• 환경영향평가
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• 제15권6호
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• pp.373-383
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• 2006

The spatial mapping of risk is very useful data in planning for disaster preparedness. This research presents a methodology for making the landslide life risk map in the Boeun area which had considerable landslide damage following heavy rain in August, 1998. We have developed a three-stage procedure in spatial data analysis not only to estimate the probability of the occurrence of the natural hazardous events but also to evaluate the uncertainty of the estimators of that probability. The three-stage procedure consists of: (i)construction of a hazard prediction map of "future" hazardous events; (ii) validation of prediction results and estimation of the probability of occurrence for each predicted hazard level; and (iii) generation of risk maps with the introduction of human life factors representing assumed or established vulnerability levels by combining the prediction map in the first stage and the estimated probabilities in the second stage with human life data. The significance of the landslide susceptibility map was evaluated by computing a prediction rate curve. It is used that the Bayesian prediction model and the case study results (the landslide susceptibility map and prediction rate curve) can be prepared for prevention of future landslide life risk map. Data from the Bayesian model-based landslide susceptibility map and prediction ratio curves were used together with human rife data to draft future landslide life risk maps. Results reveal that individual pixels had low risks, but the total risk death toll was estimated at 3.14 people. In particular, the dangerous areas involving an estimated 1/100 people were shown to have the highest risk among all research-target areas. Three people were killed in this area when landslides occurred in 1998. Thus, this risk map can deliver factual damage situation prediction to policy decision-makers, and subsequently can be used as useful data in preventing disasters. In particular, drafting of maps on landslide risk in various steps will enable one to forecast the occurrence of disasters.