• Proceedings of the KSR Conference
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• 2004.06a
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• pp.334-338
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• 2004

KTX has started commercial service from Seoul to Busan and Mokpo since April 1, 2004. The service line is composed of new-high speed line and conventional line. Before KTX is runs, the maximum operational speed on conventional line was 140km/h. In order to reduce the traveling time, operation speed of KTX must be increased on the conventional line. So, we performed test running with prototype HSR-350x and verification of safety was made in $10\%$ speed-up. Korean High Speed Train HSR-350x) was developed by G7 - R&D project. In this study, in safety aspect, several technical reviews are introduced and the possibility for reduction of traveling time is investigated on the conventional line by using HSR-350x.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.675-678
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• 2004

Comparative analysis it did the interior noise of the KTX vehicle and the P-P Semaeul vehicle from the conventional line Homan Seodaejeon-Hanam section from the research which it sees. The test result KTX vehicle appeared when the P-P Semaeul vehicle compared to 20 - 25 KM/H speed up operating commerce operation speed even, the standard values 66 dBA the lowers 55 - 62 dBA. P-P Semaeul vehicle interior noise of the identical test section 63 dBA it will compare and there is a possibility the KTX vehicle knowing from the existing line operating hour interior noise.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.788-792
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• 1993

The objective of this study is to develope a satellite dynamic simulator, which can test and analyze the performance of spacecraft attitude control, antenna pointing instruments, communication equipments and spacecraft components under the space environment. The satellite simulator can be used to predict the events such as malfunction and failure of satellites in space during operation and can be used to protect against emergencies. At first, the performance test system of attitude control is investigated which can simulate motion and verify stability of spacecraft. Our system consists of an attitude control main processor and a sub-processor including some real hardwares such as attitude sensors and actuators. In this paper, we describe the procedure of designing and manufacturing the dynamic simulator hardware, which consists of the central processor board, the sub-processor board and the sun sensor, and also communication between the components.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.601-604
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• 1996

It is well known that steam generator water level control at low power operation has many difficulties in a PWR (pressurized water reactor) nuclear power plant. The reverse process responses known as shrink and swell effects make it difficult to control the steam generator water level at low power. A new automatic control logic to remove the reverse process responses is proposed in this paper. It is implemented in PLC (programmable logic controller) and evaluated by using test equipment in Korea Atomic Energy Research Institute. The simulation test shows that the performance requirements is met at low power (below 15%). The water level control by new control logic is stabilized within 1% fluctuation from setpoint, while the water level by YGN 3 and 4 control logic is unstable with the periodic fluctuation of 25% magnitude at 5% power.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.05a
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• pp.335-337
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• 2009

Internal Pressure Maintenance Equipment absorbs internal pressure variation for it's storage has developed. The bladder ; main item of Internal Pressure Maintenance Equipment, has developed with multi-layer to prevent a penetration and to improve durability. And durability test and environment test was carried out to verify the performance in the condition that could be happened in storage or operation.

• Journal of Hydrogen and New Energy
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• v.19 no.1
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• pp.26-34
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• 2008

This study presents an aerodynamic design and an experimental performance test of a turbo air compressor consisted of mixed-flow impeller and curved diffuser for the PEM fuel cell vehicle application. Many studies compare the efficiency, cost or noise level of high-pressure and low-pressure operation of PEM fuel cell systems. Pressure ratio 2.2:1 is considered as design target The goal of compressor design is to enlarge the flow margin of compressor from surge to choke mass flow rate to cover the operational envelope of FCV. Large-scale rig test is performed to evaluate the compressor performance and to compare the effects of compressor exit pipe volume to stall or surge characteristics. The results show that the mixed-flow compressor designed has large flow margin, and the flow margin of compressor configuration with small exit volume is larger than that with large exit volume.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.8
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• pp.864-871
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• 2008

The tilting trains can run on curve track about 30% faster than conventional train without affecting passenger comfort. As the tilting trains offer the optimum means of providing faster and more comfortable rail service with minimum of environmental disturbance and capital investment, it is widely adopted for commercial operation all over the world. Over several years, the Korea Railroad Research Institute(KRRI) and Ministry of Construction and Transportation(MOCT) have been developing 200 km/h Korean tilting train, Hanvit200. Hanvit200 adopts the pendulum type tilting mechanism and hybrid car body structure, mainly CFRP combined with steel. In this paper the vibrational characteristics of Hanvit200 was investigated through Eigen vector analysis, modal test and main line running test.

• The KSFM Journal of Fluid Machinery
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• v.8 no.1 s.28
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• pp.7-15
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• 2005

Tip clearance of centrifugal compressor affects the performance. Larger tip clearance results in lower efficiency. What really affects the performance is the running tip clearance, not the cold tip clearance. When the compressor is operating, blade strain and the pressure difference between impeller backplate and hub affects the running tip clearance. This paper describes measured running tip clearance and its effects on the performance of centrifugal compressor. Cold tip clearance before operation was 0.4 mm and running tip clearance varied from 0.86 mm to 0.25 mm with impeller exit pressure. As the pressure at impeller exit increases, the running tip clearance tends to decreases. The target running tip clearance for Compressor at $100\%$ speed was 0.3 mm, and it turned out to be exactly 0.30 mm from experiment.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.1
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• pp.39-42
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• 2002

For the purpose of modeling EEG signal which has nonstationary and nonlinear dynamic characteristics, this paper propose a state feedback real time recurrent neural network model. The state feedback real time recurrent neural network is structured to have memory structure in the state of hidden layers so that it has arbitrary dynamics and ability to deal with time-varying input through its own temporal operation. For the model test, Mackey-Glass time series is used as a nonlinear dynamic system and the model is applied to the prediction of three types of EEG, alpha wave, beta wave and epileptic EEG. Experimental results show that the performance of the proposed model is better than that of other neural network models which are compared in this paper in some view points of the converging speed in learning stage and normalized mean square error for the test data set.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.703-705
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• 1999

The Power supplies used commonly in the Nuclear, Thermal and Hydraulic Power Plant are required to test the function and reliabilities. For the better contribution of reliable operation and speedy maintenance of Power Plant, it is necessary to gather and analyze the datum, to print out the result of testing using PC and proper controllers. Various kinds of power supply shall be tested and examined automatically. By storing the test results in the Database it is possible to find out the changing of characteristics of power supplies. So it is very useful to prevent any problems that may occur in the power supplies.