• Proceedings of the KSR Conference
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• 2008.06a
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• pp.820-825
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• 2008

In the article 16 of the domestic rolling stock crashworthiness regulations, the collision acceleration level during collision accidents should remain under the maximum 7.5g and the average 5g. By the way, the accelerations obtained in crash simulations and tests contain many kinds of high frequency components due to numerical oscillations or noisy signals. So, this paper aims to develop reliable post-processing methods to filter high frequency oscillations and extract the rigid body motions of passenger rail cars. For this study we used the 1-dimensional dynamic model of KHST (Korean high-speed train), and evaluated acceleration data at the driver's area in the first power car and the passenger area in the following trailer.

• Nuclear Engineering and Technology
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• v.41 no.7
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• pp.921-928
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• 2009

As part of an evaluation for an in-vessel severe accident management strategy, a coolant injection into the reactor vessel under depressurization of the reactor coolant system (RCS) has been evaluated in detail using the SCDAP/RELAP5 computer code. A high-pressure sequence of a small break loss of coolant accident (SBLOCA) has been analyzed in the Optimized Power Reactor (OPR) 1000. The SCDAP/RELAP5 results have shown that safety injection timing and capacity with RCS depressurization timing and capacity are very effective on the reactor vessel failure during a severe accident. Only one train operation of the high pressure safety injection (HPSI) for 30,000 seconds with RCS depressurization prevents failure of the reactor vessel. In this case, the operation of only the low pressure safety injection (LPSI) without a HPSI does not prevent failure of the reactor vessel.

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.898-903
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• 2002

The railroad is a means of large transportation which has many talents such as a safety and a regularity. That is a results from various confidential performance tests and evaluations of the system. The railroad system consist of various subsystems - vehicle, power supply, signal, communications, track structures, operations, etc. Among them, as an item of safety evaluation there is a measurement of wheel/rail force, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more inportant in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, it is introduced to preprocess the wheelset for measuring wheel/rail force of high speed rail, such as to treat a measuring wheelset, its finite element analysis, adhesion of strain gauges and static load test.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.11a
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• pp.533-534
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• 2002

In this paper, we studied the transient gain response in TDFA(Thulium-Doped Fiber Amplifier) theoretically. We also investigated the limitation of the gain saturation and recovery time when the short pulse trains are incident into the TDFA with the spectral gain band in 1.47${\mu}{\textrm}{m}$ for using at WDM. We can predict the interval between the pulse train, pump power and the effect of the saturation and recovery time which is affected to the amplification of the optical pulse.

• Proceedings of the KIEE Conference
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• 1999.07a
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• pp.465-467
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• 1999

The data transmission system in MAGLEV is required a high quality and high speed for a train safety and reliability driving. In the transmission channel between a vehicle and a ground-site, Gaussian noise is negligible, but impulse noise from the chopper controlled propulsoin unit and the Power supplying device is very severe. The transmission channel must be protected from these noise. In this paper, we propose a DSSS (direct-sequence spread spectrum) modulation as a new data transmission technique in the railway and analyze this data transmission characteristics.

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.549-551
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• 2003

새로운 대중교통수단의 하나로써 경전철을 도입중이거나 계획중인 도시가 늘어나고 있는 추세이다. 경전철은 장거리 선로상에서 이동하는 부하라는 관점에서 전기철도 및 지하철과 유사성을 가지고 있으나, 전철 설비가 도심의 지상에 설치되는 점과 역사설비가 비교적 간단하며 선로의 긍장이 지하철에 비하여 잘은 경우가 대부분인 경우가 특징이다. 본 논문에서는 경전철을 안전하고 효율적으로 운행하기 위한 전제조건이 되는 전력 계통의 신뢰성확보를 위한 경전철 전력계통 신뢰성평가 및 최적화방안을 도출하였다. 계통공급신뢰도는 확률이론을 이용하여 정량적으로 산출할 수 있으며 정량적 신뢰도 산출법을 이용 개별 계통구성요소의 신뢰도 특성으로부터 전체계통의 신뢰도를 계산할 수 있다. 이로써 신뢰도 측면과, 설치 및 유지보수 비용을 고려한 최적의 계통구성방안이 도출된다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.159-164
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• 1996

For the purpose of establishing laser welding condition(laser power, welding speed and beam focus) and of evaluating tailor welded blank for three kinds of thin steel sheets of SPCC, SK5M and SUS304 using in the thin plate structure such as automobile, train and so on. Their $CO_2$ laser weldability were primarily tested under various welding condition. SPCC and SUS304 thin sheets showed good weldability under some welding condition. But, high carbon steel sheet SK5M needs heat treatment after welding to obtain higher tensile strength and ductility of the welded joint. And next, laser welding condition. Butt-welded specimens were not nearly broken at weld bead. However, base material were ruptured in the direction of circumference. The forming depths by tailor weld bead. However, base material were ruptured in the direction of circumference. The forming depths by tailor welded blank were SPCC+SPCC=22~25mm, SUS304+SUS304=25~43mm and SK5M+SK5M=13~17mm.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.257-262
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• 2003

Now, the population and economical power is deeply concentrated to Seoul-metropolitan region, therefoere the provinces is so lagging behind and the country cannot get balance development. And, like metropolitan region, the more outer the living area of local wide-area city is spreading, the more serious wide-region transportation problems are. But the railroads near wide-area city fun seldom commuter train, so they cannot absorb the transportation demand of wide-area city metropolitan region. To solve above transportation problem, local wide- area cities try to make a subway or a light rail transit. But it is so difficult because the limit of public finance and original small capacity of light rail. In the paper, I propose 'Local city wide-area electric railways' system of the consortium of 'Local wide-city and province transportation union', Korean National Railroad (KNR) and local capital. A 'Local wide-city and province transportation union' operates commuter railways directly using the facilities of KNR, and local capital invests to the stations of above railways system. Therefore the commuter railway system around local wide-city region will be constructed quickly and the stations will be the strong point of local development and investment.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.762-767
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• 2003

The railroad is a means of large transportation which has many talents such as a safety and a regularity. That is a results from various confidential performance tests and evalutions of the system. The railroad system consist of various subsystems - vehicle, power spply, signal communications, track structures, operations, etc. Among them as an item of safety evaluation there is a measurement of wheel/rail force, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more important in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, it is introduced to preprocess the wheelset for measuring wheel/rail force of Gwangiu EMU, such as to treat a measuring wheelset its finite element analysis, adhesion of strain gauges and static load test.

• Journal of the Korean Society for Railway
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• v.8 no.6 s.31
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• pp.610-616
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• 2005

The Incheon International Airport Express(I'Rex) is the railroad that connects Incheon International Airport, Gimpo Airport and Seoul Station. I'Rex is now under construction, and it will be connected to Gimpo Airport by 2007, to Seoul Station by 2010. However, there has been no discussion on how th connect different routes of railway Systems. Therefore it seems likely that rail passenger demand will be lower than that of limousine bus. Therefor, this paper proposes 4 effective connecting methods for I'Rex - (1) Shuttle transport, (2) Short-distance connecting transport (Inside I'Rex, Seoul Subway Line 9, 'Han-River line') (3) Mid-distance connecting transport (Jung-ang, Tae-baek, Young-dong line) (4) Long-distance connecting transport (Korean Train Express (Korean high speed railroad)) These methods can increase the connectivity of I'Rex with existing railroads and the competition power of I'Rex against a highway.