• Journal of the Korean Society of Safety
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• v.18 no.3
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• pp.131-140
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• 2003

An accident involving a boiler can result in a disaster since it handles high-pressurized steam so that it may cause an explosion. Therefore, the boiler is very susceptible to industrial accidents. This thesis aimed to develop counter-plans to prevent industrial accidents involved the boiler. At first after collecting accident cases involving boilers, a survey on the trait of them was carried out. Ant on the other hand a qualitative analysis was conducted to draw out hazardous components in the boiler itself and their inherent relative importance was assessed. Through this procedure, 'negligence of unsafe condition' was noted as the major cause for unsafe acts whereas 'fault in work procedure' for unsafe condition. In the meanwhile, results of a hazard analysis using FMEA technique ranked gas safety devices, a switch preventing gas from under-pressurization, protect relays high. In particular, it was pointed out that the water feeding and steam subsystem has more components in hazard than other subsystems. Considering these analyses results, counter-plans to improve safety management was suggested also.

• Coupled systems mechanics
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• v.3 no.4
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• pp.345-365
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• 2014

A significant problem met in engineering practice when designing cable-stayed bridges is the failure of cables. Many different factors can lead to sudden failure of cables, such as corrosion, continuous friction or abrasion, progressive and extended crevice created by fatigue and finally an explosion caused by sabotage or accident, are some of the causes that can lead to the sudden failure of one or more cables. This paper deals with the sudden failure of cables in a special form of cable-stayed bridges with a single line of cables anchored at the central axis of the deck's cross-section. The analysis is carried out by the modal superposition technique where an analytical method developed by the authors in a previous work has been employed.

• Journal of Korea Multimedia Society
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• v.25 no.2
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• pp.189-196
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• 2022

We have developed an embedded based environment sensing module with high-resolution temperature, humidity and gas sensors to detect gas leakage under the condition of LNG injection. The developed sensing module have linearity with gas concentration. We have confirmed the developed sensing module could detect LNG gas concentration of 5 cmol/mol and 15 cmol/mol, which are gas concentration at risk of explosion. The response time of the developed module was fast within 8 seconds. Therefore it can be used to detect LNG gas leakage.

• Journal of Radiation Industry
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• v.17 no.1
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• pp.93-100
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• 2023

This study analyzes the neutron shielding performance of Soft Magnetic Material and proposes a military application. In general, the military protection facility has been constructed with thick concrete, so Soft Magnetic Material, consisting of boron, was used with concrete in this study. To do so, Monte-Carlo N-Particle (MCNP) was applied to simulate the Watt-fission neutron spectrum of ²³⁵U and ²³⁹Pu. As a result, a configuration of polyethylene and Soft Magnetic Material is evaluated about four times better than borated polyethylene concerning the atomic weight of boron inside each shielding material. Also, when a nuclear weapon explosion is simulated in MCNP, 1 mm of Soft Magnetic Material with 20 cm of concrete shows about 55% more additional neutron shielding performance compared to when Soft Magnetic Material is not used. In this work, the neutron shielding performance of Soft Magnetic Material could be identified and Soft Magnetic Material would be useful for neutron shielding if applicable to concrete structure.

• Journal of Agricultural Extension & Community Development
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• v.3 no.2
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• pp.197-209
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• 1996

Bangladesh that is known as the poorest country of the world has the large land of fertile soil and very good environment to live, even though we think she may be very bad to live. People being habituated to that good environment, the population explosion made the people to be starven, but the treatment has been simple support without deep analysis of the root of poverty. As the result it is general that the poverty is severer and severer in spite of continuous support. For the last century Korea changed from the country of poverty and despair to that of development and hope, to be model mid vision of under development countries including Bangladesh. At this point it is necessary to look back the way of development to help them to solve their poverty problem. That is the goal of this project, and this thesis is the result of it. It is evaluated for the 1st 5 years work of the project to apply the result to the next 5 years plan. This project had been proceeded from 1. Jul. 1990 to 30. Jun. 1995 at Chilmari area of Bangladesh, with teaching and training to wake up the mentality of the people, demonstration farming and cooperative association. It was proceeded as the Agriculture project of KDAB(Korean Development Association in Bangladesh, an NGO registered to Bangladesh) supported by Good Neighbors, KOICA and many churches and individuals. Especially the teaching and training work was proceeded as the branch of the Canaan Farmer`s School of Korea with instruction and support. After the basic survey for project, the confirmation of working place and the preparation of training facility, 10 times of long term training(3 months worse, boarding) was completed, with many times of short term training, informal training, demonstration farm, various demonstrating works. The results of the work are understanding of the not of problem by participatory observation, making plan to solve it, getting the trust from the people and beginning the practical work with the trainees for development of economy and living situation. The biggest problem of Bangladesh is being understood losing the desire to solve the poverty problem and the self-confidence to be able to do it. It is the conclusion that after solving the problem of thought and mentality, the education, technology and money can be effective for development. So the 1st 5 year project is evaluated as the basic work to analyse the root of problem, to chance mentality of people and to search income source. The next goal is to promote practical living level of people. For that it is necessary to develope die mentality of people including responsibility and self-confidence by teaching and training, to educate cooperative association and technology for economical development, to proceed integrated rural development work with economical development, educational improvement and reformation of environment. It is very important result that they decided to grow poultry for main economical source of Chilmari area, to do economical development work by joint operation of poultry through cooperative association.

• Asia pacific journal of information systems
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• v.4 no.2
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• pp.214-246
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• 1994

As the use of information technology continues to bring a dramatic increase in the amount of data available to managers, researchers have noted that having too much data can be as much of a problem as having too little. It becomes very important to understand the effects of "information explosion" on the way managers perform their work. This study examines the effect of the amount of available data on the process and outcome of thinking within a context where managers are equipped with computing tools. The purpose of this study is to better understand how managers respond cognitively to increased information availability. In this experiment with 104 MBAs three groups of subjects were asked to identify high and low potential market categories for effective direct mail sales based on three different amount of computer-based socioeconomic data designed based on existing research on cognition and information overload. Analyses of the outcomes showed that the group with medium amount of data used data and computer-based analysis tools most effectively and efficiently. We expect that the study will provide us a base to relate future MIS research to theories on cognition in such related fields as psychology and organizational behavior.

• Journal of the Korean Society of Safety
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• v.27 no.4
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• pp.20-25
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• 2012

The purpose of this study is to analyze the thermal characteristics and to study fire hazard of electric leakage by iron power accumulated on circuit breaker in an iron processing factory. The thermal characteristics were analyzed while current was applied to the powder for ten minutes. Results showed that temperature of iron powder at 100 mA is $160^{\circ}C$ and at 175mA is $240^{\circ}C$. The sparks have occurred as iron powder drops between two(hot line and neutral line) wires and then iron powder explosion occurred while dropping continuously the iron powder on two lines. Those who work in the iron processing industry need to periodically remove and maintain the iron powder. The thermal characteristics in this paper can be used for electrical fire investigation and for basic data of thermal characteristic of leakage current through iron powder at iron processing factories.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.2
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• pp.216-226
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• 2000

This paper presents a new method to synthesize timed asynchronous circuits directly from the specification without generating a state graph. The synthesis procedure begins with a deterministic signal transition graph specification with timing constraints. First, a timing analysis extracts the timed concurrency and timed causality relations between any two signal transitions. Then, a hazard-free implementation under the timing constraints is synthesized by constructing a precedence graph and finding paths in the graph. The major result of this work is that the method does not suffer from the state explosion problem, achieves significant reductions in synthesis time, and generates circuits that have nearly the same area as compared to previous methods.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.111-118
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• 2006

Relatively high noise emitted from Transformers of in-door-substation in urban area has become the target of public complaints and the frequency is on the rise in these days due to an extension of transformer installations and new establishment of substations. The noise consist of harmonics of a specific frequency of the twice of the electricity frequency(60[Hz]), which is hard to control by using the general sound proofing techniques. In this work, several effective methods were discussed for reducing the noise from a transformer, which is transmitted through explosion preventing shutter and air tunnels. By applying to the actual site, the effects of the methods were verified.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.3
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• pp.77-87
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• 2006

Micro- or nano-size particles are required to improve the combustion efficiency and stability in the case of solid explosives and propellants. The micro-structural properties of an energetic material strongly influence the combustion and explosion behavior. However, the traditional size reduction techniques, including milling, are not suitable for production of ultra-fine size particles. As an alternative to the traditional techniques, various re-crystallization processes based on supercritical fluids have recently been proposed. Supercritical fluids are fluids at temperatures and pressures above their critical point. In principle, they do not give problems of solvent contamination as they are completely released from the solute when the decompression occurs. Rapid Expansion Supercritical Solutions(RESS) and Supercritical Anti-Solvent Process(GAS/SAS) are representatives of a nano-size particle formation process of energetic materials using supercritical fluids. In this work, various fine particle formation processes using supercritical fluids are discussed and the results are presented.