• The KIPS Transactions:PartC
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• v.11C no.6 s.95
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• pp.787-798
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• 2004

High performance net재rking is one of key factors to provide support for data intensive applications in the Internet. Extended frame size has a major impact on end to-end performance with increasing effective TCP throughput and decreasing system overhead. Most of the research about extended frames has focused on local area network performance and the impact that extended frame size has on the system elements including memory, network interface card and so forth. In the paper, we analyse the effects of the extended frames to the other traffic flows sharing Internet paths for the wide area performance of TCP by conducting various network simulations. Results show that securing available bandwidth in no loss and low delay networks is indispensable to exploit the efficiency of extended frames.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.6
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• pp.516-525
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• 1990

This paper proposes a hierarchical control algorithm for an efficient network management of a loosely-coupled system which consists of functional division and duplicating structure with a LAN to enhance reliability and availability. The algorithm is modeled using the Perti-net and verified with the reachability tree. Here, the proposed algorithm is compared with the purely centralized control algorithm and distributed control algorithm in terms of message traffic for the network management. The result shows that the message traffic related to system performance is as low as centralized control algorithm and the system availability is independent of a specific processor failure.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1900-1904
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• 2007

지금까지 수공구조물의 설계와 기존 시설의 안전도를 평가시 수문, 수리 및 경제학적 함수들에서 발생하는 불확실성을 설명하기 위하여 안전율 또는 여유고를 증가시키거나 이들 정보의 양과 질을 증가시켜 데이터베이스를 확장하고 측정오차를 최소화시키며, 전통적인 통계해석을 적용하였다. 공공의 안전을 확보하기 위하여 설계과정에 안전율 또는 여유고가 도입되었으나 이것은 단순히 보다 높은 재현기간의 적용을 의미하며, 수문현상이 가지는 추계학적 특성보다 확정론적인 근거로부터 안전설계 개념이 개발되었다. 수자원 계획시 고려되는 부하와 저항은 확정론적인 고정치가 아니라 시간에 따라 변하고 동적이며, 무작위적이므로 확률 변수로서 고려되어야 한다. 이에 따라 최근 수자원 계획과정에서 불확실성 해석에 의한 위험도 분석 개념이 도입되고 있으며, 특히 이상기후 및 집중호우의 빈발, 급격한 도시화로 인한 유출양상의 변화 등으로 급증하고 있는 훙수피해를 감안할 때 설계빈도의 상향조정과 같은 확정론적인 방법보다는 매개변수 또는 함수의 불확실성을 고려한 위험도 해석의 필요성이 더욱 증대되고 있는 실정이다. 따라서 본 논문에서는 수자원 계획시 입력자료 및 매개변수의 불확실성과 불확실성의 분리를 고려한 홍수량의 산정 및 각 매개변수의 영향을 평가하여 홍수위험도 해석에 있어서 모델 매개변수의 영향 규명과 처리방안을 제시하고자 한다.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1559-1561
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• 1994

At present, the principle of puffer action in high current interruption is adopted in almost of the EHV(Extra High Voltage) and UHV(Ultra High Voltage) GCB(Gas Circuit Breakers). The thermal interruption capability of these GCBs critically depends on the pressure rise in the puffer cylinder at current zero. The pressure rise in the puffer cylinder depends on the puffer cylinder volume, flow passage and leakage area in the interrupter, stroke curve etc. Recently commercial CFD(Computational Fluid Dynamics ) packages have been widely adopted to calculate the pressure distribution in the interrupter. However, there are still several problems with it, e.g. very expensive price, moving boundary problem, computation time, difficulty in using the package etc. Thus, the calculation of the puffer cylinder pressure in simple and relatively correct method is essential in early stage of GCB design. In these paper, the model ing technique and computed results for EHV class GCB (HICO, 145kV 40kA and 362kV 40kA GCB) are presented and compared with available measured results.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.627-632
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• 1992

The effect of dietary pectin in the upper gastrointestinal transit rate was studied. Rats fed fiber-free diet or 10% pectin diet were offered 51-$CrCl_3,$ a transit marker. The movement of 51-Cr dose through the gastrointestinal tract was measured at intervals from 20 minutes to 6 hours after dosing. pectin significantly increased gastric emptying rate upto 3 hours after dosing. Pectin also increased small intestinal transit rate from 3 hours to 4 hours after dosing. The results suggest that delayed gastric emptying is not likely the important aspect of the mechanism by which pectin could flatten the post-prandial response of serum glucose and insulin.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1309-1315
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• 2004

The harmonic current originated from electric cars will be cause of electromagnetic interference along adjacent communication cables and troubles with signaling. It will also cause overheating in power capacitor and malfuction in protection relay. Therefore, it brought actual measurement of harmonic current by each operation mode. Because the result exceeded the value prescribed by Korea Electric Power Corporation, we constructed facilities reducing harmonic current on overloaded part at each power supply station located in conventional line (Guro, Kyungsan, and Milyang) as an optimal alternative. Then, this study compared and analyzed the reducing effect before and after constructing facility.

• The Transactions of the Korean Institute of Power Electronics
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• v.15 no.4
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• pp.259-265
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• 2010

The proposed method offers an improved control method for high power density AC/DC adapter by using more energy efficient electrical equipments. Power factor corrector (PFC) topology is based on boost topology with boundary conduction mode (BCM) and DC/DC topology is based on LLC resonant converter, which helps to reduce size of the semiconductor and the magnetic devices. Test results with 85W AC/DC adapter (18.5V/4.6A) design shows that the measured efficiency is 90% at $90V_{rms}$ input voltage with power density of $36W/in^3$. It also shows low no load power consumption of about 0.5W.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.1235-1238
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• 2012

오늘날 소프트웨어가 가지는 규모와 복잡성은 날로 심화되고 있으며, 소프트웨어 개발 시 결함을 찾아 내기 위한 테스트에 많은 시간이 소모되고 있는 실정이다. 이러한 문제점을 해결하기 위해 중요한 기술 중 하나가 결함 위치 추적(Fault Localization)이다. 이 기법을 이용하여 결함을 추적하기 위해서는 다량의 테스트 케이스를 필요로 하며, 추가로 테스트 케이스를 작성하는 것은 또 다른 개발 부하이다. 본 논문에서는 이를 해결하기 위해서 분기별 입력 조합 기반 테스트 케이스 생성방법과 시드 결과 기반 테스트 케이스 생성방법을 제안하였다. 개발자는 본 생성방법을 통해 테스트 케이스 생성에 대한 비용 절감을 기대 할 수 있다. 제안하는 내용의 효용성을 검증하기 위해 실제 예제 코드에 적용하여 평가하였다. 두 가지 방법 모두 무작위 생성한 테스트 케이스에 비해 개발자가 직접 생성하는 것과 유사한 테스트 케이스를 생성하고, 제안 방법으로 생성한 테스트 케이스의 신뢰성을 확인하였다.

• Convergence Security Journal
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• v.24 no.2
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• pp.175-180
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• 2024

Future warfare is evolving with advanced science and technology, introducing a variety of unmanned and manned combat systems. These systems generate and exchange massive amounts of information, challenging current tactical communication systems as a foundation for future communication infrastructure. To analyze the information distribution capability of the Army TIGER corps, this paper examines four scenarios: standalone ground network operation, integrated network operation, load distribution, and error recovery. Utilizing M&S results, we highlight the potential of a multilayer integrated command and control network, incorporating ground, air, and space networks, to enhance the reliability and stability of the overall communication network.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.359-369
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• 2007

This in vitro study was performed to assess the effect of surface sealing on the microleakage of class V composite resin restorations that underwent several aging treatments. Class V cavities were prepared on the buccal surface of 100 sound extracted premolars and restored with a hybrid light-cured composite resin according to the manufacturer's instructions. They were randomly divided into two groups consisting of 50 samples: group I, without surface sealing, and group II, in which margins were etched and surface sealant was applied. After thermocycling, each group was divided into five subgroups, respectively, to represent the five aging treatments: group A = no further treatment (only thermocycling), B = toothbrushing, C = load cycling, D = toothbrushing followed by load cycling, and E = aging treatment in deionized water for six months. Microleakage was assessed by examining the penetration of 2% methylene blue dye. The following results were obtained: 1. At occlusal and cervical margins in groups without surface sealing, there was no significant difference in microleakage after the several aging treatments (p>0.05). 2. The occlusal margins of groups with surface sealing showed no significant differences after the several aging treatments (p>0.05). 3. In the cervical margins of groups with surface sealing, microleakage significantly increased after load cycling or aging in deionized water for six months (p<0.05). 4. The no-further-treatment group and the toothbrushing group with surface sealing showed less microleakage than the corresponding groups without surface sealing (p<0.05). 5. The surface-sealed groups with load cycling or aging in deionized water showed no significant difference in microleakage to the corresponding groups without surface sealing (p>0.05). In conclusion, the results of this study suggest that the surface sealant infiltrating through the gap of the cervical margin exerted a positive effect on microleakage at the initial stage, but the effect was not sufficient to overcome the stress generated by the cuspal flexure during occlusal loading and water absorption.