• Journal of the Korean Institute of Gas
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• v.21 no.5
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• pp.77-82
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• 2017

Thus, chemicals are managed under 9 related central government department and 16 relevant laws with program such as Process Safety Management and Offsite Consequence Analysis in korea. Guidelines for set the endpoint concentration for chemcals based on the ERPG-2 (Emergency Response Planning Guidelines-2) and AEGL-2 (Acute Exposure Guidelines Level-2). but ERPG and AEGL do not describe exposure for less than 10 minutes. because of this, each guidelines define criteria differently for short time less than 10 minutes exposure. This indefinite exposure criteria would give rise to a confusion in the chemical plants, and potentially lead to a critical decision making error when accidents happen. In an effort to apply guidelines with evenly-distributed initial time frame, AEGL concentrations within 10 minute exposure time were evaluated by examining statistical regression curves. The results were in good agreement with those from the Probit Function based on each AEGL grade to explain 3 different threshold levels of exposure effects. Resultant re-enforced guidelines for endpoint chemical concentrations are, therefore, to provide powerful tool to assess and manage the risk associated with any potential chemical accidents at an early stage.

• Journal of the Korean Institute of Gas
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• v.24 no.5
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• pp.74-81
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• 2020

In general, when manufacturing a semiconductor, a number of hazardous and dangerous substances such as flammability, toxic, and corrosiveness are used. In particular, semiconductors are manufactured using specialty gas in processes such as CVD and etching. The specialty gas is filled in a container in the state of compressed or liquefied gas, and a gas cylinder cabinet is used as a facility for supplying this specialty gas to the semiconductor manufacturing process. When a accident occurs in the gas supply system, gas is released through a pressure release device installed in the gas cylinder to secure the safety of the supply system. In this case, the gas released inside the gas cabinet, there is a risk of leaking to the outside. After that, by analyzing the gas flow in the gas cabinet, it is intended to identify the risk associated with leak and to provide measures to prevent accidents.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.4
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• pp.304-312
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• 1998

In order to assure the reliability and integrity of structures such as bridges, Power and petrochemical plants, nondestructive evaluation techniques are recently playing more important roles. Among the various kinds of nondestructive evaluation techniques, ultrasonic technique is one of the most widely used methods for nondestructive inspection of internal defects in structures. For the reliable quantitative evaluation of internal defects from the experimental ultrasonic signals, a numerical analysis of ultrasonic scattering field due to a defect distribution is absolutely required. In this paper, the SH-wave scattering by multi-cavity defects using elastodynamic boundary element method is studied. The effects of shape of defects on transmitted and reflected fields are considered. The interaction of multi-cavity defects in 50-wave scattering is also investigated. Numerical calculation by the boundary element method has been carried out to predict near field solution of scattered fields of ultrasonic SH-wave. The presented results would be useful to improve the sensitivity of flaw defection for inverse analysis and pursue quantitative nondestructive evaluation for inverse problem.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.2
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• pp.162-170
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• 2009

As one of promising solutions to overcome high oil price and energy crisis, the construction market of high value-added LNG plants is spotlighted world widely. The purpose of this manuscript is to introduce domestic activities to develop risk assessment technology against overseas monopolization. After analyzing relevant specific features and their technical levels, risk assessment program, non-destructive reliability evaluation strategy and safety criteria unification class are derived as core technologies. These IT-based convergence technologies can be used for enhancement of LNG plant efficiency, in which the modular parts are related to a system with artificial optimized algorithms as well as diverse databases of facility inspection and diagnosis fields.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.5
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• pp.384-389
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• 2014

In this paper, the result of an ultrasonic performance demonstration are analyzed. The requirements for an ultrasonic performance demonstration (PD) for a nuclear power plant were first described in ASME B&P Code Section XI, Appendix VIII (1989 winter addenda). In order to establish the performance demonstration scheme in Korean nuclear power plants, the Korea Hydro & Nuclear Power Co. Ltd (KHNP) has developed the Korean Performance Demonstration (KPD) system for the for the ultrasonic examination of nuclear power plants. An analysis of the ultrasonic performance demonstration results from 2004 through 2013 will improve the detection of flaws in an ultrasonic examination, as well as the further development of the KPD training system.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.177-193
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• 2004

최근의 화물자동차파업사태 등으로 우리나라 물류체계의 경쟁력제고를 위한 여러 가지 논의가 진행되고 있다. 그 중에서도 환경친화적이며, 사회적 비용이 저렴한 철도화물의 수송분담율을 높여야 한다는 의견이 많이 나오고 있다. 우리나라 물류체계의 근본적인 문제점은 도로운송량의 증가보다 트럭의 공급과잉으로 트럭운송사업자의 수익은 매우 낮고, 철도, 해운 등 대량운송수단의 분담율이 낮아 전체적인 수송효율성이 낮은 것을 들 수 있다. 이러한 문제점의 해결은 트럭의 과잉공급을 억제하고, 제조업 물류비 중 46.5%를 점하고 있는 운송비용을 절감하는 것이 핵심적인 방안이라고 하겠다. 이에 본 논문에서는 철도화물의 활성화와 우리나라의 철도구조개혁의 성공적인 추진을 위해서 우리와 지형조건이 비슷하고, 1987년에 철도민영화를 시행하여 현재 16년이 경과한 일본철도화물의 현황을 분석하여, 현재까지의 문제점을 밝히고 또한 우리나라의 철도화물수송정책에 시사하는 바를 정리해 보았다. 1987년 민영화 이후 일본철도화물수송현황을 보면 영업거리, 화차대수를 포함한 수송능력 감소로 수송량은 감소하였으나, 화물수송의 장거리와 추세와 컨테이너수송량의 증가, 인력감축으로 영업성적은 전반적으로 향상되고 있다. 문제점으로는 경영면에서는 낮은 생산성 그리고 노후장비 등으로 인한 높은 설비투자비지출, 선로사용료 등의 부담 등이 지적되었다. 운영상에서는 현재 선로를 소유하지 못하여 네트워크가 부족하여 자유로운 열차편성이 어렵고, 포워더 기능이 없어 현재 전체물량의 85%를 점하는 소운송구간에서 다른 운송주체간의 수송으로 일관수송서비스에 어려움이 있으며, 직접적인 영업을 하지 못하여, 새로운 수요창출에 어려움이 있다. 이러한 문제점의 해결책으로는 먼저 정부의 인프라에 명확한 책임분담과 이에 따른 지원이 필요하다. 이와 같은 철도화물활성화의 정책수립필요성의 배경에는 철도화물수송이 효율성과 환경친화성, 높은 안전성 등 사회적 비용을 감소시키는 장점을 가지고 때문이다. 철도화물운송회사도 현재의 수송기능과 함께 포워더로서의 기능을 가져야 할 것이며, 운임인하노력과 속도향상을 위한 노력을 계속하여야 할 것이다.

• Journal of Energy Engineering
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• v.24 no.3
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• pp.6-12
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• 2015

The welding technology has been used in almost all industries such as automotive, shipbuilding, power plants and industrial machinery. In this study, the design and implementation of PLC $CO_2$ welding automation system were investigated. For these purposes, the structure analysis for driving supporter was performed and specification of automatic voltage regulator, mutual interface of system and circuit diagram were designed in order to contrive power-saving system. As the results, the stability of design for driving supporter could be convinced by numerical analysis and PLC automatic welding system was suitable for welding automation of structural-manufacturing factory capable of producing various and small amount products. Therefore, it was confirmed that PLC $CO_2$ welding automation system could contribute to productivity, stable quality and power-saving.

• Journal of the Korean Institute of Gas
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• v.16 no.4
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• pp.16-22
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• 2012

The use of welding process has been increased for manufacture of machine, bridges, ships, gas facilities and so on together with development of welding technique. Accordingly, it has been needed to develop the welding methods considering higher productivity and safety design for manufacture of their welding structures. In this study, it was studied basically on characteristics of fatigue strength and fatigue life in full penetrated cruciform fillet weld zone in relation to material thickness, welding passes, loading direction and notch radius of toe zone. Most of fatigue failure occurred in toe zone of cruciform fillet weld joint. Fatigue strength and fatigue life are under the influence of stress concentration due to notch radius and flank angle of toe zone. The metal of toe zone annealed and diffused by multi-layer welding and acicular ferrite structure formed by the result improved fatigue strength and fatigue life.

• Journal of the Korean Institute of Gas
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• v.22 no.2
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• pp.29-33
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• 2018

Accident likelihood is growing due to a correlation for gas and electricity installed in the area of dense energy consumption like traditional market and underground shopping center. In order to prevent and respond accident risks related to gas and electricity in this area, it should be monitored and predicted for factors of gas leak or electricity by developing safety management system. This study is about accident prediction model development considering fire risk factor related to gas accident. The temperature variation characteristic near a gas burner was analyzed. Also, accident prediction algorithm and related module were developed to prevent fire in the area of dense energy consumption.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1080-1087
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• 2019

For a risk analysis in a chemical process, it is important to reflect correctly the characteristic properties of the target process. In this study, computational fluid dynamics (CFD) was adopted for the advanced risk analysis in a residual hydro desulfurization (RHDS) process by considering operation condition, layout of instruments and facilities, atmospheric condition, and wind direction. Release and explosion simulations for the RHDS by using FEA (Finite Element Analysis) and CFD showed the applicability of 3D scanning methods for estimation of release hole size and release amount.