• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.285-290
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• 1994

The influence of elevated temperatures on the mechanical properties of concrete is important for fire-resistance studies and also for understanding the behavior of containment vessel, such as nuclear reactor pressure vessels, during service and ultimate condition. The present study is to clarify the damage/deterioration of concrete structures that are subjected to high temperature exposure. To this end, comprehensive experiments are conducted. The major test variables are the peak temperatures, rate of temperature increase, and sustained duration at peak temperature. The results include weight loss residual compressive strength and stress-strain curve. From those results, residua compressive strength formula and stress-strain relationship are proposed.

• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.291-300
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• 1994

The influence of elevated temperatures on the mechanical properties of concrete is important for fire-resistance studies and also for understanding the behavior of containment vessel, such as nuclear reactor pressure vessels, during service and ultimate condition. The present study is to clarify the damage/deterioration of concrete structures that are subjected to high temperature exposure. To this end, comprehensive experiments are conducted. The major test variables are the peak temperatures, rate of temperature increase, and sustained duration at peak temperature. The results include weight loss residual compressive strength and stress-strain curve. From those results, residua compressive strength formula and stress-strain relationship are proposed.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.403-410
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• 2003

Annual roadbed failure due to the rainfall has brought out the social and economic damage such as the loss of life and property, the consumption of time and cost for recovery, and the delay of logistics in railway. However, there was not an appropriate way that could be used as a permanent solution. As a suggestion of the answer to this problem, the method using Geotextile Container was considered for the rehabilitation of the failed railway roadbed, and the numerical analysis is applied for the evaluation of the slope stability. This study focused on the most common case among the roadbed failures. In addition, the investigation for the applicability of this method as a permanent use was made.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.421-424
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• 1998

In this paper are presented a newly proposed 3D monte carlo (MC) damage model for the dynamic simulation in order to more accurately and consistently predict the implant-induced point defect distributions of the various ions in crystalline silicon. This model was applied to phosphorus implants for the ULSI CMOS technology developement. In additon, a newly applied 3D-trajectory split method has been implemented into our model to reduce the statistical fluctuations of the implanted impurity and the defect profiles in the relatively large implanted area as compared to 1D or 2D simulations. Also, an empirical electronic energy loss model is proposed for phosphorus and silicon implants. The 3D formations of the amorphous region and the ultra-shallow junction around the implanted region could be predicted by using our model, TRICSI(Transport ions into crystal-silicon).

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.15-18
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• 2009

In recent years electric devices and telecommunication facilities were often damaged by surge generated lightning discharge. When the service was interrupted by failure of electrical devices due to surge the social loss is very enormous. Therefore in order to protect electrical systems against lightning, SPDs(Surge protective device) have been used But damaged SPDs often make some troubles like fire and interrupt of service. In this work, 3rd harmonic leakage current defection method was applied as the diagnosis of SPD degradation and the effectiveness of this method was verified by field survey.

• Proceedings of the KIEE Conference
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• 1989.07a
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• pp.443-446
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• 1989

154kV insulator strings are frequently damaged by lightning strokes, overvoltage and contamination. And this insulator damage inflicts a loss on the power company. The purpose of this paper is to develop the arcing horn as a protective device of 154kV insulator strings against lightning flashover and overvoltages. So We have developed the arcing horn which is suitable for 154kV transmission line and estimated the performance of arcing horn by high current arcs and high voltage tests.

• International Journal of Safety
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• v.7 no.1
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• pp.21-25
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• 2008

The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154kV dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in l54kV power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method (FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.239-244
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• 2011

This study is aimed to develop fundamental technology on the smoke control method by simulation model and scale model simulation technique in pressure differential systems. Thereby, this research aimed to establish design elements and technologies required for smoke control system that is suitable to pressure differential systems of the high-rise buildings in order to minimize the loss of lives and property damage in case of fire.

• Fashion & Textile Research Journal
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• v.7 no.1
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• pp.85-90
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• 2005

The effect of sodium acetate to reduce the fiber damage and hardening of acetate fabrics during alkaline treatment is studied. The optimal condition is controlled concentration 2%, at $50^{\circ}C$ for 6 minutes and at $70^{\circ}C$ for 2 minutes through the result of weight loss, shrinkage and tensile strength. Alkaline treated acetate fabrics under optimal condition show softer than untreated acetate fabrics. Alkaline treatment with sodium acetate brings the reduction in hardening and shrinkage in internal fiber of acetate fabric. Also, alkaline treatment with sodium acetate improves the tensile strength of acetate fabrics compared with only alkaline treatment. The moisture regain of acetate fabrics is also improved by alkaline treatment under optimal condition.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.107-110
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• 2008

This study is aimed to develop fundamental technology on the smoke control method by simulation model and scale model simulation technique in underground space. Thereby, this research aimed to establish design elements and technologies required for smoke control system that is suitable to underground spaces of the high-rise residential-commercial and office buildings in order to minimize the loss of lives and property damage in case of fire.