• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.2
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• pp.39-43
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• 2009

we studied and analyzed a tree mortality of 7 species(Pinus koraiensis etc) in surface forest fire area. In this results, the order of tree mortality was Cryptomeria japonica>Pinus koraiensis>Pinus densiflora>Pinus thunbergii>Larix leptolepis>Pinus rigida>Quercus. More damaged crown was higher tree mortality and more d.b.h was less tree mortality. Especially, oak trees in which a damage rate of crown was less 30% almost survived.

• Journal of the Korea Safety Management & Science
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• v.8 no.2
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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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• v.26 no.2
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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.

• Journal of Environmental Health Sciences
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• v.44 no.4
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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.

• Journal of Korean Society for Quality Management
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• v.25 no.3
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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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• v.4 no.5
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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.

• Proceedings of the KSR Conference
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• 2009.05a
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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.

• The Journal of Engineering Geology
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• v.19 no.3
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• pp.295-306
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• 2009

The risk assessment of groundwater and soil in Sasang industrial complex in Busan Metropolitan City was carried out in order to estimate risks to human health and the environment. The carcinogenic risk (CR) of receptors to soil and air was not identified. However, the CRs for TCE and PCE were 6.7E-6 and 1.0E-5, respectively. Hazard quotient (HQ) and hazard index (HI) did not appear through air exposure pathways. Yet the HQ and HI of soil were 3.4E-5 and 5E-5, respectively, and lower than the critical value (1.0). On the contrary, HQ and HI with respect to groundwater were calculated as 0.7 (not hazardous) and 1.4 (hazardous). The constituent reduction factor (CRF) for TCE in the study area was determined as 2.5, and thus remediation work is demanded. As a result of sensitivity analysis for 18 exposure factors, eight exposure factors (life time of carcinogens, age, body weight, exposure duration, exposure frequency, dermal exposure frequency, water ingestion rate, and soil ingestion rate) varied with the variation of risk.

• YAKHAK HOEJI
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• v.57 no.1
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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.

• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.4
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• pp.107-113
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• 2009

This paper considers the influence of floc on the sedimentation rate for the cohesive material. The effects of floc density and size changes were also taking into consideration during the experiment. The settling velocity of a discrete floc was measured in a quiescent water column. Floc diameter and density were investigated using a modified Stokes equation with some constants such as water density, viscosity, material density and the floc fractal dimension $n_f$ obtained from the relationship between the floc diameter and the floc settling. The floc diameter of quartz and alumina increased at increasing initial concentrations. The floc size of quartz with increasing NaCl concentration varied between approximately 0.8 um to $10{\mu}m$. Floc density decreased as floc size increased. The floc settling velocity and the floc diameter have a straight line relationship on a logarithm. The floc fractal dimension nf was 2.65 with increasing of initial concentration and 2.93 with increasing of NaCl. The exponent n to predict the settling velocity was proposed and varied from 1 to 1.93.