• Composites Research
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• 제37권2호
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• pp.101-107
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• 2024

해저케이블은 케이블의 손상 시 높은 유지 보수 비용과 문제점들을 해결하기 위해 다양한 종류의 보호기 자재를 사용한다. 특히 파랑 및 해류 등의 외력 요소 들로부터 케이블을 보호하기 위해 사용되는 대표적인 보호기자재로 유연보호튜브를 들 수 있다. 유연보호튜브는 폴리우레탄 85A 초 탄성 재료로 구성되어 있어 기계적 거동을 계산하기 위해 실험 결과를 기반으로 한 물성치를 이용한다. 본 연구에서는 유연 보호 튜브를 대상으로 해석적 방법을 사용하여 휨 성능과 인장 성능을 살펴보았다. 해석에 사용된 물성치는 폴리우레탄 85A의 다축인장 실험을 통해 확보된 물성 값을 이용하였다. 유연보호튜브는 최대 굽힘 모멘트 기준치인 15 kN·m와 인장하중의 기준치인 50 kN에 대해 휨 성능과 인장 성능을 분석하였다. 해석 결과 유연 보호 튜브의 최대 굽힘 모멘트가 15 kN·m일 때 MBR은 13 m로 휨 성능이 확보되었으며, 인장하중이 50 kN일 때 최대 수직 변위가 968 mm를 나타내 인장성능이 확보됨을 확인할 수 있었다.

• 한국강구조학회 논문집
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• 제21권1호
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• pp.27-35
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• 2009

주요 철골구조체는 일정한 시간동안 내화성능을 발휘하기 위한 내화조치를 필요로 한다. 본 연구는 철골기둥의 내화피복 국내인정 제품의 내화성능을 분석 평가함을 목적으로 한다. 대상제품은 보드피복과 뿜칠피복 두 종류의 제품을 대상으로 하여 샘플연구를 하였다. 국내기준과 유럽기준에 기초하여 제품의 내화성능을 분석하였다. 또한 국내기준을 유럽기준의 성능설계관점에서 분석 고찰하였다. 온도적 측면에서 국내기준의 내화성능은 일반적으로 안전하다고 사료되지만, 재료의 물성치 자료확충, 강재온도 산정방법, 프로필계수, 화재시 내력검증 등의 특성을 반영할 필요가 있다고 사료된다.

• 한국풍공학회지
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• 제22권4호
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• pp.155-161
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• 2018

현대 사회에서 도시화와 온난화로 인한 태풍 등 강풍에 의한 피해는 증가될 것으로 예상된다. 본 연구에서는 기 개발된 창호보호장치의 보강성능을 시험하기 위해 비 보강된 판유리와 보강된 판유리의 2점 가력실험과 등분포하중 실험을 수행하였다. 창호보호장치의 보강성능은 휨 성능평가를 토대로 평가하였다. 창호보호장치의 이론적 성능 산정은 탄성하중법과 처짐 곡선의 미분방정식을 이용한 수식해석과 Midas-Gen을 이용한 전산해석을 통해 수행하였다. 실험값과 이론 산정 값의 최대하중 가력시의 판유리 중앙부 최대 처짐 비교를 통해 산정방법의 유효성을 검토하였다. 창호보호장치 부착 시 실험조건하에서 40%까지의 응력감소효과와 동일 하중하에서 71.4%까지의 처짐 감소 효과가 있었다. 판유리를 보요소로 해석한 결과보다 판유리를 판 요소로 해석한 결과가 오차가 적으므로 성능 판단 시 가능하면 판 요소로 해석을 수행하는 것이 유리하다.

• Interaction and multiscale mechanics
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• 제3권4호
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• pp.405-414
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• 2010

The performance of full-scale steel and composite bridge safety barriers under vehicle crash is evaluated by using the nonlinear explicit finite element code LS-DYNA. Two types of vehicles used in this study are passenger car and truck, and the performance criteria considered include structural strength and deformation, occupant protection, and post-crash vehicle behavior. It can be concluded that the composite safety barrier satisfies all performance criteria of vehicle crash. Although the steel safety barrier satisfies the performance criteria of occupant protection and post-crash vehicle behavior, it fails to satisfy the performance criterion of deformation. In all performance evaluations, the composite safety barrier exhibits a superior performance in comparing with the steel safety barrier.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.275-277
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• 2005

In a lithium-ion battery which is being used in many portable electronic goods, electrolyte is disaggregated and then the gas is happened when electric charging volt is over the 4.5V. So, the pressure on the safety valve is increased and electrolyte is leaked out in the cell. It leads to the risk of explosion. On the other hand, in the case which the battery is discharged excessively, the negative pole is damaged and the performance of the battery is deteriorated. The protection module of a lithium-ion battery is used for preventing such risk and the inspection system is needed to check the performance of such protection module. In this research, a PC-based auto inspection system is developed for the inspection of a battery protection module using Dallas chipset. In the inspection system, AVRl28 chip is used as a controller and the communication protocol is developed for the data communication between the protection module and the AVR128 chip. And GPIB interface is used for the control of measuring devices. Also, MMI environment is developed using LabView for convenient monitoring by the tester.

• 대한안전경영과학회지
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• 제13권1호
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• pp.41-49
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• 2011

The automatic fire detection system is an important facility installed with focusing on minimizing the damage from a fire. This paper presents in the followings as the methods to reduce the false alarm of the automatic fire detection system; first, to prepare for legal standard so that revised legal standard can be applied to the fire fighting property prior to revision; second, to introduce the performance based fire detection protection design in the law based fire protection design; third, to maintain the wiring of worn-out detector; forth, to introduce an evaluation system to the education for the fire warden; fifth, to extend the standard of MTBF(meantime between failure) of the detector; sixth, to extend of installing the analog type detector; seventh, to improve the structure of reset switch.

• Corrosion Science and Technology
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• 제7권4호
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• pp.197-200
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• 2008

In this paper, physical scale modeling was employed to identify the configurations of ICCP system and the electric field signatures. Computational boundary element modeling technique has been used to simulate the performance of the CP system and to predict the associated electric fields signatures. The optimization methods combined with the computer models and physical scale modeling will be presented here, which enable the optimum system design to be achieved both in terms of the location and current output of the anode but also in the location of reference electrodes for impressed current cathodic protection(ICCP) systems. The combined methodology was utilized to determine optimal placement of ICCP components (anodes and reference electrodes) and to evaluate performance of ICCP system for the 2%, 10% and 14% wetted hull coatings loss. The objective is to design the system to minimise the electric field while at the same time provide adequate protection for the ship. The results show that experimental scale modeling and computational modeling techniques can be used in concert to design an optimum ICCP system and to provide information for quickly analysis of the system and its surrounding environment.

• Nuclear Engineering and Technology
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• 제34권3호
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• pp.259-267
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• 2002

NFPA-803 has been referred as the Fire Protection Standard at the Nuclear Power Plants of Pressurized Water Reactor. This Standard has been used as the fire protection regulation, containing prescriptive requirements with deterministic methodology. Recently, with cumulative efforts by the U.S. Nuclear Regulatory Commission and Utilities in America to establish a new Standard, including a quantitative evaluation methodology, NFPA-805, the Performance-Based Standard for FIRE Protection for Light Water Reactor Electric Generating Plants was issued and approved by the American National Standards Institute as an American National Standard with an effective date of February 9, 2001. This paper presents an analysis result from the computer modeling for the fire simulation In addition, it proposes the idea that this kind of analytic method can be available for the facilities design of fire prevention and protection fields, as well as an evaluation for the fire suppression system with a quantitative analysis for the thermal phenomena in fire compartments in Nuclear Power Plants.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.1166-1169
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• 2005

This paper describes a new transient voltage suppressor(TVS) with a low insertion loss and a high cut-off frequency to protect antenna circuit from transient voltages. Conventional protection devices have some problems such as a low frequency bandwidth and a high insertion loss. In order to improve these limitations, a coaxal type TVS, which consists of a gas tube is developed. The performance of the proposed transient voltage suppressor is tested by using a combination surge generator specified in IEC 61000-4-5 standard and by using a network analyzer of 40 MHz ${\sim}$ 5 GHz bandwidth. From the experimental results, it is confirmed that the proposed TVS has an enough protection performance in a low insertion loss and a high cut-off frequency.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권6호
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• pp.1327-1342
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• 2010

With the wide deployment of biometric authentication systems, several issues pertaining security and privacy of the biometric template have gained great attention from the research community. To resolve these issues, a number of biometric template protection methods have been proposed. However, the design of a template protection method to satisfy four criteria, namely diversity, revocability and non-invertibility is still a challenging task, especially performance degradation when template protection method is employed. In this paper, we propose a novel method to generate a revocable minutiae-based fingerprint template. The proposed method consists of feature extraction from fingerprint minutiae pairs, quantization, histogram binning, binarization and eventually binary bit-string generation. The contributions of our method are two fold: alignment-free and good performance. Various experiments on FVC2004 DB1 demonstrated the effectiveness of the proposed methods.