• Proceedings of the KSR Conference
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• 2007.11a
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• pp.244-250
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• 2007

The electric train in the first line subway runs faster in the block from Suwon to Cheonan than the general block. The faster run results in the deterioration of ride quality due to the increase of noise and vibration. To reduce the noise and vibration of the electric train, a running test of the electric train was performed in the block from Suwon to Cheonan. The experimental results show that the sources of the noise and vibration basically comes from the irregularity of the railroad track and the connection part between car body and bogie. The possible countermeasure of the high speed electric train can be the reinforcement of the center pivot to have more flexibility and the frequent maintenance of electric train.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1590-1593
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• 2007

Establishing the remote monitoring system of the moving test train is the important issue for the railway systems that provide comfort travel to the passengers. But it is not easy to transmit train's test data to remote site because the train runs tunnels. This paper represent the development results of Hanvit 350 remote monitoring system using wireless data communication system which is installed in the test train. This system can provide both correct positions of unstable track and train's running status such as speed, kilopost and acceleration.

• Journal of KSNVE
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• v.8 no.4
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• pp.603-608
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• 1998

In order to obtain basic data for the prediction of railway noise propagation, the noise radiation characteristics (source position, radiation directivity, etc) of trains were measured by using the sound intensity method. The measurements were performed at a side of railway by setting an intensity-probe array. As the measurement results, it was found that rolling noise due to interaction between wheel and rail and motor noise radiation from the lower part of train are dominant. The location of main sound sources can be described as being at the height of 0.1m in the center line of track, and the radiation directivity in the cross section of actually running trains are presented as a dipole source.

• Proceedings of the IEEK Conference
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• 2003.07e
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• pp.1960-1963
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• 2003

For applications such as video surveillance and human computer interface, we propose an efficiently integrated method to detect and track faces. Various visual cues are combined to the algorithm: motion, skin color, global appearance and facial pattern detection. The ICA (Independent Component Analysis)-SVM (Support Vector Machine based pattern detection is performed on the candidate region extracted by motion, color and global appearance information. Simultaneous execution of detection and short-term tracking also increases the rate and accuracy of detection. Experimental results show that our detection rate is 91％ with very few false alarms running at about 4 frames per second for 640 by 480 pixel images on a Pentium IV 1㎓.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.870-875
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• 2008

The main objective of this paper is to control a trajectory tracking of the fish-mimetic robot by CPG (Central Pattern Generator), which is biological approach. CPG is biological neural networks that generate rhythmic movements for locomotion of animals, such as walking, running, swimming and flying. Animals show marvelous ability of autonomous dynamic adaptation for an unsteady fluid dynamic environment or various environments. So, we propose the 3-DOF CPG controller to track the trajectory of the fish robot in plane motion. The conformity of the proposed control algorithm is validated by simulation for a fish robot model, which is made by a commercial dynamic package.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.984-996
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• 2009

When evaluating the general subgrade states such as geology, stiffness, underground water, compaction and deformation in the Gyeongbu high speed railway, some applicable testing methods should be selected because lots of trains are currently running. The applicable methods includes not only non-destructive tests such as GPR test, electricity resistivity test, MASW proving, but also standard penetration test (SPT), core test, elastic wave tomography through drilling boreholes and measurements using settlement measuring system or inclinometer, etc. In order for evaluating the subgrade states in the Gyeongbu high speed ralway, this study performed GPR test in several sections and drilling boreholes whose locations were chosen after comparing GPR test results and track maintenance history. Furthermore, the progress of subgrade deformations was analysed by comparing previous and this time GPR test results. The results of this study shall be used to understand the general states of currently operating Gyeongbu high speed railway.

• International Journal of Railway
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• v.5 no.2
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• pp.71-76
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• 2012

Recently, axle load, operating speed and traffic density on railroads have had a tendency to increase and thereby cause additional pressure applied on used track. These operating conditions frequently result in service failure due to wear caused by wheel-rail contact and fatigue damage under cyclic loading. Among rail defects, the transverse crack, which has been the most dangerous type of fatigue damages, is developed from the subsurface crack near the rail running face and grows perpendicular to the rail surface. Therefore, it is necessary to investigate systematically the growth behavior of transverse crack for rail steel under mixed mode. In this study, the fatigue crack growth behavior of the transverse crack in rail steel was experimentally investigated under mixed-mode variable amplitude loadings.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.255-261
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• 2008

The importance of maintenance of rail surface defects is increasing according to the KTX operation. That is because during high speed operation of rolling stocks, rail surface defects shorten fatigue life of rail, accelerate track degradation and deteriorate ride comfort. Rail grinding has been applied for effective rail maintenance in Kyeong-Bu HS line. This paper evaluates the effectiveness of rail grinding in term of rail fatigue life. To this end, the stresses of the ground rail are measured under KTX running and the equivalent stress range is calculated by RMC after the frequency analysis done with Rainflow counting method. Also, Pamglen-Miner rule is applied to predict the fatigue life of ground rail. The result of the analysis shows that the fatigue life of ground rail is increased by 15%.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.485-488
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• 2011

본 연구에서는 경부고속철도의 콘크리트궤도에서 열차주행안전측면에서 관리해야할 레일패드강성의 상한값을 차량 및 궤도의 동특성과 운영환경을 고려하여 결정하는 방법을 제시하였다. 차량과궤도의 상호작용의 해석의 중요 입력파라메타인 궤도틀림과 관련하여 프랑스 및 독일에서 제시한 궤도틀림 PSD(Power Spectral Density)와 경부 1단계구간 콘크리트궤도에서 계측한 궤도틀림 자료를 통하여 얻은 PSD를 기초로 하여 넓은 범위의 주파수영역에서 적용할 수 있는 콘크리트궤도의 궤도틀림 PSD를 제시하였다. 제시된 PSD 기준모델을 사용하여 시간영역에서의 궤도틀림 입력을 Random Generation을 통하여 구한 후 개발된 차량-궤도 상호작용해석 기법을 사용하여 레일패드에 따른 윤중감소율을 산정하였다. 산정된 윤중감소율에 대하여 국내 철도차량 안전기준에 관한 규칙의 탈선계수 규정을 적용하여 주행안전측면에서 허용할 수 있는 레일패드강성의 상한값을 제시하였다.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1020-1023
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• 2009

A purpose of this study measure the acceleration of operating KTX high speed train to find out something wrong to obtain reliable the acceleration measurement data. The existing measurement system come about a difference between measurement data of running off the track with the acceleration measurement data of operating KTX high speed train. Therefore, the measurement system needs make up for the weak points in the current system. This study analyze existing measurement system and the acceleration measurement data to introduce the synchronization of the existing measurement system and the acceleration measurement and will be reasonable to this sampling through field test.