• 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 Electrical Engineering and Technology
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• v.12 no.6
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• pp.2365-2377
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• 2017

This paper addresses two interrelated problems concerning the tracking control of pod propulsion unmanned surface vessel (USV), namely, the modeling of pod propulsion USV, and tracking controller design. First, based on MMG modeling theory, the model of pod propulsion USV is derived. Furthermore, a practical adaptive neural tracking controller is proposed by backstepping technique, neural network approximation and adaptive method. Meanwhile, unlike some existing tracking methods for surface vessel whose control algorithms suffer from "explosion of complexity", a novel neural shunting model is introduced to solve the problem. Using a Lyapunov functional, it is proven that all error signals in the system are uniformly ultimately bounded. The advantages of the paper are that first, the underactuated characteristic of pod propulsion USV is proved; second, the neural shunting model is used to solve the problem of "explosion of complexity", and this is a combination of knowledge in the field of biology and engineering; third, the developed controller is able to capture the uncertainties without the exact information of hydrodynamic damping structure and the sea disturbances. Numerical examples have been given to illustrate the performance and effectiveness of the proposed scheme.

• Journal of the Korean Society of Safety
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• v.34 no.4
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• pp.22-31
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• 2019

The flammable liquid conductivity is an important factor in determining the generation of electrostatic in fire and explosion hazardous areas, so it is necessary to study the physical properties of flammable liquids. In particular, the relevant liquid conductivity in the process of handling flammable liquids in relation to the risk assessment and risk control in fire and explosion hazard areas, such as chemical plants, is classified as a main evaluation item according to the IEC standard, and it is necessary to have flammable liquid conductivity measuring devices and related data are required depending on the handling conditions of the material, such as temperature and mixing ratio for preventing the fire and explosion related to electrostatic. In addition, IEC 60079-32-2 [Explosive Atmospheres-Part 32-2 (Electrostatic hazards-Tests)] refers to the measuring device standard and the conductivity of a single substance. It was concluded that there is no measurement data according to the handling conditions such as mixing ratio of flammable liquid and temperature together with the use and measurement examples. We have developed the measurement reliability by improving the structure, material and measurement method of measuring device by referring to the IEC standard. We have developed a measurement device that is developed and manufactured by itself. The test results of flammable liquid conductivity measurement and the data of the NFPA 77 (Recommended Practice on Static Electricity) Annex B Table B.2 Static Electric Characteristic of Liquids were compared and verified by conducting the conductivity measurement of the flammable liquid handled in the fire and explosion hazardous place by using Measuring / Data Acquisition / Processing / PC Communication. It will contribute to the prevention of static electricity related disaster by taking preliminary measures for fire and explosion prevention by providing technical guidance for static electricity risk assessment and risk control through flammable liquid conductivity measurement experiment. In addition, based on the experimental results, it is possible to create a big data base by constructing electrostatic physical characteristic data of flammable liquids by process and material. Also, it is analyzed that it will contribute to the foundation composition for adding the specific information of conductivity of flammable liquid to the physical and chemical characteristics of MSDS.

• Journal of Ocean Engineering and Technology
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• v.26 no.3
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• pp.46-54
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• 2012

More than 70% of the accidents that occur on offshore installations stem from hydrocarbon explosions and fires, which, because they involve blast effects and heat, are extremely hazardous and have serious consequences in terms of human health, structural safety, and the surrounding environment. Blast barriers are integral structures in a typical offshore topside module to protect personnel and safety critical equipment by preventing the escalation of events caused by hydrocarbon explosions. Many researchers have shown the adequacy of the simple design tool commonly used by the offshore industry for the analysis and design of blast walls. However, limited information is available for corrugated blast wall design with explosion impact response characteristics. Therefore, this paper presents a parametric study on the explosion impact response characteristics of an offshore installation's stainless steel corrugated blast wall. This paperalso investigates and recommends design parameters for the structural design of a corrugated blast wall based on a nonlinear structural analysis of experiential results.

• Journal of forensic and investigative science
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• v.1 no.1
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• pp.72-87
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• 2006

Accidents and terrorist acts that utilize explosives have a great influence on society and thus require a prompt investigation for the arrest of the culprit. However, such investigations are often met with difficulties due to the vastness of the crime scene, restrictions on approaching the scene, fragility of the evidence, complexity of investigation, and the lack of expertise. In spite of such facts, scientific investigation regarding explosives have not been widely studied in Korea. Therefore, the focus of this research primarily concerns the effective scientific investigation methods in cases of accidents that involve chemical explosives. Although the a systematic investigation method is at the heart of scientific investigation in cases of explosive accidents, it is only at its rudimentary stage. Therefore, in this research, a systematic investigation method is put forth for the 'scene investigation, the documentation of the scene, and the collection and processing of evidence. Further, I have set forth a 'scene investigation check list' the ensure a thorough scene investigation and to promote an exhaustive evidence collection that would guarantee the admissibility of such evidence in court. The above efforts were aimed at simplifying the currently complicated investigation system. 1) In the future, a guidebook that can be generally applied to accidents involving explosives in Korea ught to be produced, a continual systematic education and integrated training excises for investigators ought to be established, laws that require additives in explosives ought to be instituted so that the type, components, and source of explosives can be identified, and lastly, a database that contain information on former explosion accidents, trends, and techniques of criminal activities that involve explosion accidents should be compiled.

• Explosives and Blasting
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• v.37 no.4
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• pp.10-16
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• 2019

Information on overpressure, positive phase duration, and impulse are required to assess the effects of shock waves or pressure waves on the structure. In this study, the overpressure and positive phase duration were determined by applying the Multi-Energy Method, which is found to be effective in analyzing the explosion of vapor clouds. Based on the total heat of combustion estimated in the cyclohexane vapor cloud explosion in the Nypro Ltd(UK), overpressure and positive phase duration at the distance of 40, 80, 120, 160, 200, 240, 280, 320, 360(m) from the source of explosion were evaluated. Overpressure was shown to decrease exponentially and positive phase duration increased almost linearly with distance. A probit function was used to assess the probability of damages for the structures at each distance using the overpressure and impact obtained at the above mentioned distances. The Analyses of probability of damages have shown that there is a high probability of collapse at distances within 120m, major damage to structures within 240m, and minor damage and breakage of window panes of structures occur over the entire distances.

• Journal of the Society of Disaster Information
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• v.20 no.2
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• pp.293-301
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• 2024

Purpose: Ministry of Environment statistics reveals more than 132 fire·explosion accidents in South Korea between 2014 and 2023. Among them, fire and/or explosion accidents are very impactive in their scale and consequence. This study aims to suggest a new method of reasonable way to calculate the ventilation rate of indoor facility handling hazardous chemicals based on their inflammability. Method: A new method to calculate the ventilation rate is based on the physicochemical properties of the chemicals handled, which is more reasonable compared with the current regulation based only on the floor area of the facility. Result: Considering the physicochemical properties, 178 chemicals based on their inflammability were studied and 168(94%) met the criteria for the current regulation. Some materials have been shown to require too much or too little ventilation rate. Conclusion: Through this study, a reasonable method of calculating the required ventilation rate was proposed. This should be applied to ensure the safety of workers to deal chemicals.

• Journal of the Korean Home Economics Association
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• v.36 no.12
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• pp.129-143
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• 1998

The purpose of this study was to develop a Korean Coping Strategy Scale and to examine coping characteristics of Korean housewives form urban low-income families using this Scale. Two hundred and forty mothers were either interviewed or filled out this Coping Strategy Scale and Demograpic Information Questionnaire. The Coping Strategy Scale consisted of 14 items under 4 dimensions of problem-solving, support-seeking, emotion-regulation/explosion, and abandonment. Item analysis and construct validation were found acceptable. The alpha coefficient of the Scale was 73. The results showed that the mothers used problem-solving most as a coping strategy, followed by supportseeking and emotion-regulation/explosion. Abandonment coping strategy was used least frequently. The demographic variables of mother's and their husbands' age, duration of marriage, income and expenditure per moth were significantly related to mothers' coping strategies.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.6 no.7
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• pp.151-158
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• 2016

The 21st century is an era of knowledge innovation. Under the era background of knowledge explosion and information explosion, the competition among countries is ultimately talent competition. High-end talents are the core element of national competitiveness. Today, with the rapid development of science and technology and knowledge changing with each passing day, the cultivation of students' creativity is the requirement of social development and national progress. This paper makes a comparison between the creativity of business school students in China and Korea with questionnaire survey. Empirical study and comparative study with university students by grade in China and Korea are performed. The test results indicates that there are differences between Korean and Chinese students. Also, university students' creativity are different by grade. This study finds internal reasons for creativity differences and puts forward counter measures and methods for improving students'creativity.

• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.43-48
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• 2004

The Explosion of Content ·Over 80％ of enterprise content is unstructured(Fulcrum Research) ·Content volume is growing by over 200％ per year (Forrester Research) ·There are all kinds of Unstructured Content including Documents, Output, Web, Rich Media, Code etc ·ECM Market growing to more than ＞＄2.6 Billion in 2003. (Frost ＆ Sullivan)(omitted)