• 한국산학기술학회논문지
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• 제6권2호
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• pp.178-182
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• 2005

본 논문에서는 오브컴 위성 통신 및 X.400 통신 프로토콜을 이용하여 글로벌 위치 확인 시스템을 구현하는 논문으로 본 시스템은 인터넷을 통해서 전 세계 어디에서나 이동 및 고정 물체의 위치를 확인할 수 있는 양방향 데이터 통신을 제공한다. 본 연구에서는 데이터 통신 링크를 구축하기 위해서 X.400 프로토콜, 그리고 SIP(Serial Interface Protocol) 및 자체 정의한 제어 프로토콜을 사용하였다. GPS수신기와의 인터페이스를 위하여 사용자 단말기와 연결된 데이터 프로세서도 설계 및 제작하였다. 실시간 실험을 통해서 본 연구에서 제안한 글로벌 위치확인 시스템이 정해진 프로토콜에 따라서 잘 동작하는 것을 확인하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2594-2599
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• 2011

In Korea, the HEMU-400X(High-speed Electric Multiple Unit-400km/h eXpress) has been developed since 2007 and will be operated over 400km/h in 2013. It is necessary to prepare test-bed section in Honam high-speed railroad to take the maxim running speed test for the HEMU-400X developed. In order to determine proper test-bed sections for the maximum speed of 400km/h, TPS(Train Performance Simulation) program with the data of train model, running resistance, traction power and braking capacity was used to analyze the train performances such as locations, speeds and power consumptions by times. In this study, the specifications of the HEMU-400X project and the route conditions of the Honam high-speed railroad under construction were utilized for the TPS program to determine the optimal test-bed sections for the maximum speed of 400km/h.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.201-206
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• 2009

In the testing stage of HEMU-400X(next Korean high speed train) developing project, maximum speed(400km/h) tests will be conducted. On present and near future conditions of the overhead contact lines, 400km/h is over the design speed criteria. The predictions of current collection performance including the percentage loss of contact(arcs level) parameter through dynamic interaction simulation of HEMU-400X maximum speed test run are described in this paper. Various simulations are conducted at the condition of two different contact wire tensions to draw the proper contact wire increasing values in the 400km/h test line under the available contact wire tension supporting condition of that line.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1-6
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• 2011

In Korea, high-speed train(HEMU-400X) system with distributed power is being developed, and the highest test speed of this train is 400km/h. This developed the first high-speed train as a distributed power train in Korea, as well as for the development of train system and evaluation system included evaluation technology is needed. Accordingly, a comprehensive and efficient OMS(Overall Measurement System) was build up for verifying the performance of HEMU-400X. By the case study of the G7 and TTX, OMS of HEMU-400X was improved the test performance and maintainability. In particular, the existing Window-based systems has a limit to the control, due to this reason OMS applying enhanced RT(Real-time) system. In this study, compare the advantages and disadvantages of RT systems with Window-based systems, as well as the configuration of the RT systems.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.88-93
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• 2011

The aerodynamic drag characteristics of HEMU-400X which has been being developed for the maximum speed of 430km/h were analyzed experimentally as the variations of the pantograph cover configurations to reduce the acoustic noise and the aerodynamic drag of the pantograph system. The wind tunnel tests were performed with three pantograph cover models upon 1/20 scaled 5-car model of HEMU-400X. Two kinds of wedge shapes which induce up-flow in the vicinity of the pantograph and one cone shape which reduces the whole train drag were used in order to compare the aerodynamic characteristics as the pantograph cover shape changes. The each axial force of 5 each car was measured at a time with the test velocities, 30, 40, 50, 60m/s. Through the wind tunnel test the base drag forces of HEMU-400x model and the forces by the pantograph cover on the train model were investigated and the aerodynamic drag characteristics of the train model by the pantograph cover configurations were analyzed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.58-63
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• 2010

HEMU-400X train have been developed and will be operated over 350km/h. In this paper, the influence of vertical alignment on running behavior and safety for HEMU-400X train was instigated by numerical analysis. The wavelength and amplitude of vertical alignment were considered in scenario of this numerical analysis. This research is based on just numerical analysis and the final result which include measurement will be published in the future.

• 대한핵의학회:학술대회논문집
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• 대한핵의학회 2004년도 추계학술대회 및 총회
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• pp.400.2-400.2
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• 2004

• 한국전자통신학회논문지
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• 제6권5호
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• pp.621-627
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• 2011

본 논문에서는 로드-풀을 이용하여 X-band에서 on-Wafer 상태의 GaN HEMT 소자에 대한 성능을 분석하고 분석한 결과를 바탕으로 최적의 임피던스 점을 분석하였다. 패키징 하기 전 on-Wafer 상태에 있는 반도체 소자의 최적의 임피던스 분석을 통해 소자 자체에서 최적의 성능을 내는 방안을 제안하였다. Gate length가 0.25um이고 Gate Width가 각각 400um, 800um인 소자에 대한 최적의 임피던스를 선정하여 성능을 분석한 결과, 400um는 $P_{sat}$=33.16dBm(2.06W), PAE=67.36%, Gain=15.16dBm의 성능을 가지며, 800um는 $P_{sat}$=35.9 dBm(3.9W), PAE=69.23%, Gain=14.87dB의 성능을 보였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 춘계학술대회
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• pp.140-142
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• 2011

본 논문에서는 모바일 그래픽프로세용 특수목적 연산 회로를 설계하였다. 특수목적 연산회로(SFU)는 6개의 연산, 즉, $1/{\chi}$, $\frac{1}{{\sqrt{x}}$, $log_2x$, $2^x$, $sin(x)$, $cos(x)$를 지원한다. 특수목적 연산 회로는 높은 정밀도 조건을 만족하기 위해 IEEE 표준 부동 소수점 형식을 사용하는 2차 다항식 minimax 알고리즘을 사용하였으며, 높은 연산 성능을 위해 5-단 파이프라인 구조를 갖고 있다. 설계한 특수목적 연산회로 는 65nm 삼성 CMOS 표준셀 공정 조건에서 약 23,000개의 게이트로 구성되며, 약 400 Mhz의 동작 주파수를 가진다. 설계된 회로는 파이프라인 구조로 동작하므로 약 400 MOPS(Million Operations Per Second)의 연산 성능을 갖고 있어서, 고성능 3차원 그래픽 프로세서에 적용이 가능하다.

• 한국수소및신에너지학회논문집
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• 제23권6호
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• pp.581-587
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• 2012

Thermal aging effect on NSR kinetics was studied over Pt/Co/Fe/Ba/$Al_2O_3$ catalyst. The amount of $NO_x$ uptake over Pt/Co/Fe/Ba/$Al_2O_3$ calcined at $400^{\circ}C$ increased with increasing NSR temperature from $200^{\circ}C$ to $400^{\circ}C$, where amount of $NO_x$ uptake is the highest at $400^{\circ}C$ with mol ratio of $NO_x$/Ba = 0.5. Thereafter, the amount of $NO_x$ uptake at $400^{\circ}C$ decreased with the higher calcination temperature, where Pt/Co/Fe/Ba/$Al_2O_3$ catalyst calcined at $700^{\circ}C$ showed an amount of $NO_x$ uptake with the mol ratio of $NO_x$/Ba=0.062. Result of XRD and NSR showed that Fe addition into Pt/Co/Fe/Ba/$Al_2O_3$ suppressed sintering of Pt crystallites and make $NO_x$ uptake larger, compared to no addition of Fe into Pt/Co/Fe/Ba/$Al_2O_3$ catalyst. From BET result, it was found that the change of specific surface area was relatively small by the thermal aging process. Therefore, it was found that the sintering of Pt crystallites caused the decrease of $NO_x$ uptake during NSR reaction and Fe played a role to suppress the sintering process of Pt crystallites caused by thermal aging.