• 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.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.57-60
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• 2011

EPS패널의 열방출율과 가스유해성에 대한 연구는 꾸준히 진행되어왔다. 그러나 그 동안의 시험 결과는 KSF ISO 5660-1(콘칼로리미터) 시험규정에 의한 소형시편을 이용한 것으로 난연제의 과다투입 또는 심재의 변형이 쉬워 결과를 신뢰하기 힘들고 실제 생산되는 크기의 샌드위치패널의 난연성능을 판단하기 힘들다. 따라서, 보다 정확한 실물화재시험의 필요성이 요구되고 있다. 난연 EPS샌드위치패널과 일반EPS샌드위치패널의 실물화재 실험결과 난연EPS샌드위치패널은 기타재료의 샌드위치패널과 열방출율, 연기발생율, 부분별 온도분포, 플래시오버등과 같은 난연성능이 EPS샌드위치패널과 우레탄폼패널보다 우수하며, 글라스울과 비슷한 성능을 나태내는 것을 확인 할 수 있다. 그래서 시공성, 경제성 등의 EPS샌드위치패널의 장점을 그대로 유지하며 난연제의 코팅법을 통해 우수한 난연성능을 확보하였다.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.12
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• pp.1039-1045
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• 2016

We investigated the protection capability of a plate against high speed projectiles demonstrating collision and penetration behaviors by finite element analysis. The element erosion method was used for penetration analysis, which showed that the speed of the projectile was slightly reduced by the collision with the protection plate. Protection capability was measured by the projectile's attitude angle change because the damage of our tanks by projectiles was also dependent on the projectile-tank collision angle. When the length of the protection plate was sufficiently long, the projectile was severely deformed and incapacitated. In the case of a small plate, the projectile was deformed only in the collision region. Thus, projection capability was investigated by the change of attitude angle. The effect of collision angle, velocity, and length of the plate on the rotational and vertical velocities of the projectile was investigated.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.9 s.112
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• pp.795-803
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• 2006

In this paper, we studied hierarchical channel coding scheme using unequal error protection method fur consecutively broadcastingservice under the rain attenuation of Ka band satellite broadcasting. Unlike time-sharing methods, which are design for different channel coding scheme in according to different modulation, unequal error protection method is made in such way that minimum distance between signals are different for importance of signals with same modulation. Consequently we proposed optimal method according to performance analysis.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.442_443
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• 2009

A large wind farm should satisfy the requirements for a grid and accomplish the optimization of the wind farm system. In that point of view, the wind farm intertie protection system, which must consider the Fault Ride-Through (FRT) requirement for more reliable protection, should be improved. This paper proposes a modified distance relay suitable for protection of a wind farm intertie considering a FRT requirement. The frequency change is used to discriminate the intertie fault from a outside zone fault. The performance of the proposed algorithm is verified using a PSCAD/EMTDC simulator.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.1822-1831
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• 2014

Micro-grid is connected to the main power grid through a static switch. One of the critical issues in micro-grids is protection which must disconnect the micro-grid from the network in short-circuit contingencies. Protective methods of micro-grid mainly follow the model of distribution system protection. This protection scheme suffers from improper operation due to the presence of single-phase loads, imbalance of three-phase loads and occurrence of power swings in micro-grid. In this paper, a new method which prevents from improper performance of static micro-grid protection is proposed. This method works based on artificial neural network (ANN) and able to differentiate short circuit from power swings by measuring impedance and the rate of impedance variations in PCC bus. This new technique provides a protective system with higher reliability.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.3019-3021
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• 2005

In this paper we suggest a novel temperature detection method utilized in direct over-temperature protection circuit modeling. The suggested model detects temperature variation using Rds(on) characteristics of MOSFET, while the conventional methods are using extra devices such as a temperature sensor or an over-temperature detection transistor. The temperature-dependant MOSFET model is implemented using Spice ABM(Spice Analog Behavior Model). The direct over-temperature protection circuit was designed including it. We verified effectiveness of the temperature dependant Rds(on) model characteristics and performance of the direct over-temperature protection circuit on PSpice simulation

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.2
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• pp.47-49
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• 2004

Gate protection $SiN_x$ as an alternative to a conventional re-oxidation process in Dynamic Random Access Memory devices is investigated. This process can not only protect the gate electrode tungsten against oxidation, but also save the thermal budget due to the re-oxidation. The protection $SiN_x$ process is applied to the poly-Si gate, and its device performance is measured and compared with the re-oxidation processed poly-Si gate. The results on the gate dielectric integrity show that etch damage-curing capability of protection $SiN_x$ is comparable to the re-oxidation process. In addition, the hot carrier immunity of the $SiN_x$ deposited gate is superior to that of re-oxidation processed gate.

• Journal of Auto-vehicle Safety Association
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• v.9 no.4
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• pp.14-19
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• 2017

The mortality rate of car-pedestrian accidents is quite high compared to the frequency of accident. Recently, governments and insurance companies tend to establish and implement new safety standards for pedestrian protection such as EURO-NCAP and K-NCAP. The performance for the pedestrian protection has been gradually improved, but it is still insufficient. Therefore, various studies for the pedestrian protection are being carried out. The car-pedestrian accident is simulated in order to study to the upper legform test of the EURO-NCAP protocol. A pedestrian dummy model is employed and the results are discussed.