• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.93-98
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• 1999

We had investigated combustion properties of rice bran dusts. Decomposition of rice bran dusts with temperature were investigated using DSC and the weight loss according to temperature using TGA in order to find the thermal hazard of rice bran dusts, and the properties of dust explosion in variation of their dust with the same particle size. Using Hartman's dust explosion apparatus which estimate dust explosion by electric ignition after making dust disperse by compressed air, dust explosion experiments have been conducted by varying concentration and size of rice bran dust.According to the results for thermodynamic stability of rice bran dust, there are little change of initiation temperature of heat generation and heating value for used particle size. But initiation temperature of heat generation decreased with high heating rate whereas decomposition heat increased with particle size. Average maximum explosion pressure was $10kgf/cm^2$ for 60/70 mesh and $1.5mg/cm^2$ dust concentration.

• 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.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1998.10a
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• pp.413-420
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• 1998

In this paper, two methods, Stepp's and EQHAZARD, are introduced and applied to a recent earthquake catalog for the entire Korean Peninsula that can estimate the seismicity by incorporating the incompleteness of the earthquake catalog. EQHAZARD method, different from Stepp's method in that it used priori information besides the assumption of stationary Poisson process of the earthquakes, produces the higher seismicity rate for the smaller earthquakes. EQHAZARD method are also used to estimated the incompleteness of the recent earthquake catalog for the southern part of the Korean Peninsula in terms of the Probability of Activity for the specified earthquke magnitude classes and time periods. It is believed that the Probability of Activity thus obtained can be used as a strong priori information in estimating the seismicity for a seismic source within the region where there are not enough earthquakes detected. Finally, it is demonstrated that the arbitrary selection of the methods. of incompleteness analysis brings quite different seismic hazard results, which suggests the need to employ a rigid quantitative method for incompleteness analysis in estimating the seismicity parameters in order to reduce the uncertainty in the Seismic Hazard Results with the EQHAZARD method being one of the competent practical alternatives.

• Journal of the Korean Society of Safety
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• v.21 no.5 s.77
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• pp.53-59
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• 2006

Standard safety management costs can not be applied to each site with same rate, it is very difficult, because it depends on the experience, work method, work kind, work progress schedule, and hazard level of each construction company. Therefore, this study is to find out hazard level of each work kinds through questionnaire and interview and investigate analyze the status which standard safety management costs have been used. Also, this study is to show reasonable rates of standard safety management costs in construction industry and to set up countermeasures against those problem after reviewing its status in korea with in Japan and Europe. The domestic system of standard safety management costs is not considered in the foreign country, while only related subjective items have been investigated and evaluated for this study. This study is to investigate eleven project kinds of domestic system, first, and to investigate eleven items of apartment bldg, office, civil work such as bridge, tunnel, dam, plant etc, secondly. Additionally, three items of gymnasium, railway, particular steel tower are investigated in this study. Also this study is to investigate and analyze performed costs of presently processing worker finished work so that it shows a new reasonable rate against standard safety management costs in construction industry, in order to make basial data and material to be systemized.

• 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.

• Journal of the Korean Statistical Society
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• v.36 no.1
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• pp.93-109
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• 2007

Gamma distributions are some of the most popular models for hydrological processes. In this paper, a very flexible family which contains the gamma distribution as a particular case is introduced. Evidence of flexibility is shown by examining the shape of its pdf and the associated hazard rate function. A comprehensive treatment of the mathematical properties is provided by deriving expressions for the nth moment, moment generating function, characteristic function, Renyi entropy and the asymptotic distribution of the extreme order statistics. Estimation and simulation issues are also considered. Finally, a detailed application to drought data from the State of Nebraska is illustrated.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.75-79
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• 2008

As Information Technology developed, Information requirement has been went higher. In the field of GIS(Geographic Information System) more information is processed more quickly and accurately. Especially, quick analysis of forest fire information (topography, ignition point, weather condition, etc.) over a wide area is essential in order to minimize victim, environmental damage, and economical damage, decide course of evacuating, estimate a fire spread course, and attack resource arrangement. We determined a fire spread distance at each unit time through an experiment with various slope degrees and distinction of flat, upslope and downslope. For the tests on the upslope, as the slope increased, the rate of spread increased. On the downslope in contrast with the upslope, as the slope increased, the rate of spread decreased. We analyzed a spread rate of forest fire on each slope as the method classified upslope(+) and downslope(-) using the results obtained from the experiment. Consequently, the proposed method is able to be used to effectively support the attack of forest fire by providing accurate predictions of fire spread.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.4
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• pp.370-380
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• 2009

Reliable hazard and risk communication is needed to prevent the safety accident & occupational disease through right use of chemicals and MSDS(Material Safety Data Sheet) is mainly used as such a tool of communication. MSDS policy has been put into effect in order to prevent the safety accident & occupational disease through right use of chemicals and fulfill workers' right to know. If information on MSDS lacks reliability due to its inaccuracy, prevention of the various effects related with environmental safety & health in advance is not possible to achieve. The most essential thing regarding authoring MSDS is to exactly evaluate the composition and ingredients of the chemical and include reliability-guaranteed information. Therefore, in this study reliability was evaluated on MSDSs in 15 aromatic hydrocarbons(benzene, toluene, xylene, etc.) manufacturers and ways to secure reliability of MSDS were suggested. The results showed 93.5% of composition agreement rate and 89% of reliability on each section in MSDSs. In order to curb MSDSs with low reliability, examination on CBI(confidential business information) in MSDS, certification of MSDS, collection and verification of MSDS are suggested.

• Journal of the Society of Disaster Information
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• v.10 no.1
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• pp.71-83
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• 2014

This study carried out an experiment in order to compare thermal characteristics after collecting dust generated in the process of disposing of waste tire, plywood flour in the process of manufacturing plywood, salicylic acid dust in the process of manufacturing functional soap, and dust in the process of manufacturing wheat powder, which has potential fire and explosion hazard. According to the results of experiment, the analysis showed that all samples subject to the experiment were in the condition where heat flux decreased and temperature decreased as the quantity of added talc was increased. This shows that decomposition rate decreased, and hazard decreased. However, in all of samples subject to the experiment, as heating rate increased, endothermic onset temperature moved to the low-temperature part, and the amount of absorbed heat was largely increased. This showed that the decomposition hazard of sample increased as heating rate increased, according to the analysis. Besides, TGA experiment results showed that thermal stability was secured because total weight loss decreased as the amount of talc was increased for all samples subject to the experiment regarding the ratio of weight loss. It is expected that the continuous research and supplementation of dust explosion mechanism in the future will contribute to the establishment of measures for the effective dust explosion prevention.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.2
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• pp.188-194
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• 2015

The powered purse seine fishery is an important fishery accounting for 19.4% of adjacent water fishery production in Korea, and the commercial fishing is associated with high rate of fatal and non-fatal occupational injury. The hazard analysis for the fishermen's safety of offshore large powered purse seiner was conducted to serve as a basic data for improving the healthy and safe working environment of fishermen using fishermen's occupational accidents of the national federation of fisheries cooperatives (NFFC) in 2013 (n=583). As a result, the occupational accident occurrence rate of this fishery was 182.6‰ in all industries 30.9 times the rate of that. In addition, death and missing rate was found to have a very serious level management to 25.1‰ in all industries of death of 17.5 times. The accident occurred in 72.3 to 85.8% was happened at sea. The others, slipping and struck by object etc occurred more frequently in order in the frequency of accident occurrence pattern. However, the occurrence rate of death and missing did not match the frequency of accident pattern. In other words, slipping occurred frequently higher while death and missing risk was not high. And the contact with fishing gear and fall in the waters was low while death and missing risk was high. The results are expected to contribute for identification and assessment of safety hazard occurred in offshore large powered purse seiners.