• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.664-675
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• 2010

Recently environment-friendly construction method is major trend in both domestic and world constrction fields. In this paper High Functional Performance Agent(Hi-FA) which has various improved engineering characteristics different with conventional Portland cement grouting, such as high viscosity, liquidity, void filling ability, early hardening, and separation resistance, was analyzed by field and laboratory test. Also soil improvement and existing deep foundation protection works were performed and analyzed using Hi-FA.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.238-240
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• 2007

This paper present adaptation method of rail potential test to verify DC railway system's performance and safety. For protection of person and utility caused by rail potential rise, international standard to limit rail potential rise is made and rail potential is tested at the time of plan and construction of DC railway system in foreign country. So, we need rail potential test at the opening time and prepare a continuous monitoring technique of rail potential and a limitation method of rail potential rise. For these, we describe cause of rail potential rise, international standard about rail potential, protection principle, an example of calculation and measurement, and adaptation method for performance test.

• Proceedings of the KIEE Conference
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• 2002.11d
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• pp.253-256
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• 2002

Generally, the owners of the facilities adopt CP(Cathodic Protection) Systems to protect the corrosion accidents previously. The developed countries have secured the standard of CP systems through the various researches and consolidation of the rules. So in the first stage. I had been studied the international standards; JSCE, NACE Standard, ASTM, DNV, Australian Standard etc. and standardized the CP systems about items performance. specifications and so on. In this thesis, I have been studying the results of standardization of performance test methods of CP rectifier to apply in Korea.

• Fire Science and Engineering
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• v.33 no.6
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• pp.53-62
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• 2019

A recent trend shows that more buildings are being constructed as mixed-use (residential and commercial) properties for efficient land use. This has led to an increased frequency in the occurrence of fires and the associated potential risks. In particular, in case of high-rise apartments, at least one of the elevators in each building is installed for evacuation purposes separately from the emergency elevator; therefore, for a combined ancillary room and emergency elevator platform situation, the structure is inevitably in series with the evacuation elevator platform. Thus, a proposal for a new type of ventilation zone based on existing national fire safety codes is required to achieve smoke control performance. To this end, the air egress velocity and differential pressure of each ventilation zone are checked using the "CONTAM" software; further, an alternative is proposed to secure smoke control performance for series structures.

• Fashion & Textile Research Journal
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• v.20 no.5
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• pp.569-582
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• 2018

The purpose of this study is to verify the impact protection performance and to evaluate the activity, design, fit, and pad characteristics of the fall impact protection clothing for elderly women. The protective clothing was designed as pants type and underwear type, and an impact protection pad in the form of a tightly connected regular hexagon piece was inserted in the hip and hip joints. The pad was made of two kinds of foam single pad and foam and gel combination pad so that they could be inserted into pants type and underwear type, respectively. The results of the shock absorption performance of the fall impact protective clothing showed that when the impact force of 4601N was applied to the pants type protective clothing, the impact force was reduced by 29% in the foam pad type and 26% in the gel and foam pad type. When the force of 5113N was applied to the underwear type, it decreased by 40% in the foam pad type and by 34% in the gel and foam pad type. As a result of wearing evaluation of subject group, it was found that fit and activity of underwear type was better than that of pants type. Foam pad type was evaluated to be lighter than gel and foam pad type in both the subject and the expert group and the gel and foam pad was evaluated to be more flexible in the expert group.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.5
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• pp.521-526
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• 2020

Airfield pavements, such as runways and taxiways, are essential for smooth take-off and landing of fixed-wing aircraft and are the most important installation for the military to carry out air operations during wartime. Therefore, in wartime, it is necessary to reduce the damage to these installations and repair them in the shortest possible time. Recently, the pattern of attack is changing from the use of conventional high explosive which is to create large craters to the use of multiple warheads weapon system which is to effectively attack enemy's airfields but unrelated to accuracy. Hence in this study, through identifying the specification and composition of multiple warheads weapon system, we checked the protection performance and damage patterns of the pavement when explosion occurred on the installed military runway and taxiway by the multiple warheads weapon system. And The multiple warheads weapon systems is able to cause extensive damage but the destructive power of each warhead is not as great, so I would like to propose an airfield pavement design plan for minimal protection against such attacks.

• Journal of Satellite, Information and Communications
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• v.10 no.4
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• pp.6-11
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• 2015

The ESD(electrostatic discharge) protection performance of PPS(PMOS pass structure) embedded N-type silicon controlled rectifier(NSCR_PPS) device with different GPNS(Gate to Primary $N^+$ Diffusion Space) structure was discussed for high voltage I/O applications. A conventional NSCR_PPS standard device with FPW(Full P-Well) structure and non-CPS(Counter Pocket Source) implant shows typical SCR-like characteristics with low on-resistance(Ron), low snapback holding voltage(Vh) and low thermal breakdown voltage(Vtb), which may cause latch-up problem during normal operation. However, our proposed NSCR_PPS devices with modified PPW(Partial P-Well) structure and optimal CPS implant demonstrate the improved ESD protection performance as a function of GPNS variation. GPNS was a important parameter, which is satisfied design window of ESD protection device.

• Smart Structures and Systems
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• v.20 no.2
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• pp.127-137
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• 2017

Identification of damping characteristics is of significant importance for dynamic response analysis and condition assessment of structural systems. Damping is associated with the behavior of the energy dissipation mechanism. Identification of damping ratios based on the sensitivity of dynamic responses and the model updating technique is investigated with numerical and experimental investigations. The effectiveness and performance of using the sensitivity-based model updating method and vibration monitoring data for damping ratios identification are investigated. Numerical studies on a three-dimensional truss bridge model are conducted to verify the effectiveness of the proposed approach. Measurement noise effect and the initial finite element modelling errors are considered. The results demonstrate that the damping ratio identification with the proposed approach is not sensitive to the noise effect but could be affected significantly by the modelling errors. Experimental studies on a steel planar frame structure are conducted. The robustness and performance of the proposed damping identification approach are investigated with real measured vibration data. The results demonstrate that the proposed approach has a decent and reliable performance to identify the damping ratios.

• Fashion & Textile Research Journal
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• v.21 no.5
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• pp.606-617
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• 2019

The present study newly developed a firefighters' protective jacket and pants using a Nomex honeycomb structured layer (HPC) in cases of being exposed to flashover or flameover. This study evaluated the protective and comfort functions of an HPC compared to the current KFI firefighters' protective clothing (FPC). The results are as follows. First, thermal protective performance (TPP) of fabric layers was 2.75 times greater for HPC than FPC at $125kW/m^2$. Second, the predicted second and third degree burn areas were smaller for HPC than FPC when using a flame manikin. Third, thermal insulation using a thermal manikin was 0.2 clo greater for HPC than FPC. Fourth, there were no marked differences in maximal performance, mobility, and microclimate temperature/humidity between FPC and HPC through human wear trials. The thermal insulation of HPC was higher than that of FPC; however, any negative effect of HPC thermal insulation on the comfort functions for firefighters was not found. In conclusion, the newly-developed HPC provided more protection in reducing burn injuries from $125kW/m^2$, while no negative impact on maximal performance, mobility and thermal comfort functions of firefighters, which is appropriate for quick-evasive tactics at the flashover, flameover or back draft fires.

• Journal of the Korean Society of Radiology
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• v.11 no.4
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• pp.189-195
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• 2017

Radiation protection equipment has widely used to protect human body from radiations, for example X-ray and gamma ray. The material of the radiation protection equipment is mainly lead (Pb) which has brought out lead poisoning and pollution when the equipment is fallen into disuse. This problem makes research and development find new Pb-free materials for use of radiation protection. Manufacturing and evaluation processes for developing those material were carried out repletely until obtaining the performance of protection rate. In this study, combination possibility of shielding material was studied using Geant4 monte carlo simulation. X-ray tube under the same condition in the real measurement of the protection rate was simulated, and X-ray tube spectrum was obtained. The X-ray tube spectrum was applied to study on the protection rate and lead equivalent. The porosity effect was simulated, and was one of key factors to determine protection rate or lead equivalent in radiation protection sheet of Pb-free.