• 한국철도학회논문집
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• 제10권4호
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• pp.381-387
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• 2007

In this paper, crashworthiness of the EMU carbody of Incheon Metro is numerically evaluated against two types of overhead line structures (headspan and portal-type). The material of the EMU carbody is stainless steel (SUS301L), and that of the overhead line structures is the structural steel (SS400). The EMU carbody is analyzed under collision conditions, such as upright side-on impact, side-on roof impact and angled roof impact scenarios, to be collided against the headspan type or the portal type at the speed of 64.4km/h, respectively. It is concluded from the numerical results that the overhead line structures will not do so much harm to the EMU carbody of Incheon Metro for various collisions caused by derailment. Furthermore, the overhead line structure of the portal type is superior to that of the headspan type in the crashworthy point of view.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.969-974
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• 2008

As the railway becomes higher, the reliable stability and riding comfort of higher railway are required. To improve the riding comfort of high-speed trains, it is very helpful to use active suspension system for railway. In Japan, the high-speed train, Shinkansen has adopted semi-active suspension system and now it is running in the main trunk. In this paper, the authors introduce several technical trends of vibration control methods of Japanese Shinkansen. And the installation of semi-active suspension to HSR 350x and the test result of test run on the Kyoung-Bu high speed ling are also explained. After development of HSR 350x, new R&D national project of high speed train is progressed by Ministry of Land, Transport, and Maritime Affairs. This project is the development of Electric Multiple Unit of high speed train with 400km/h of maximum test speed. These result would be helpful to progress next generation high speed project.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1201-1208
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• 2008

Ubiquotuous technology should be adopted in railroad business to provide passenger's security and convenience. In this project, IT and smart sensor technologies are reviewed, benchmarked, designed, and implemented. The target system is the next generation high speed train to be developed and operated in Korea with the maximum speed of 400km/h. Wireless sensor network with smart sensors is implemented around a train car. PC-like IT terminal will be designed and implemented so an individual passenger can use it to do information retrieval through the Internet, personal data processing, the e-learning, shopping on the railroad, and so on. These provision will give comfort, convenience, and safety of a passenger during his/her trip.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.835-840
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• 2008

Next Generation High Speed Train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project is in stage of concept design and so, it needs to take some review and analysis the characteristics of suspensions on the view of concept design. A vehicle modeling is made of modified Korean High Speed Train bogie model with Vampire program and analyzed the effect on the dynamic performances according to the variation of primary and secondary suspension characteristics. The results would be useful to manage the potential risks in the next stage of basic and precision design that will be done by the manufacturing company.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.387-392
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• 2008

Next Generation High Speed Train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project is in stage of concept design and so, it needs to take some review and analysis the characteristics of suspensions on the view of concept design. A train dynamic modeling is modified with the one car model presented in the previous conference and it was extended to 6cars models having the same suspensions and added some connection's characteristics between the cars with Vampire program. It is used to analyze the effect on the dynamic performances according to the variation of primary and secondary suspension characteristics in the condition of 6 cars configuration. The results would be useful to manage the potential risks in the next stage of basic and critical design that will be done by the manufacturing company.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.1056-1064
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• 2008

It is estimated that the running of locally-developed next generation High Speed Trains with maximum speed of 400km/h will help to deteriorate track components. It was presented rail defect coding system in UIC 712R includes the definitions of damage types of rail, maintenance procedures, and etc to detect and maintain. It is necessary to make a track maintenance manual determining track maintenance periods using the standardization of damage types of track components such as: sleeper, fastener, elastic pad. In this paper, the damage types of high speed track components are investigated by referring domestic and foreign literatures. And then the damage types of rail given in UIC 712R is reclassified more particularly and classified damage types of track components using internal high speed railway. In conclusion, this paper suggests standardization for damage types of track components on internal high speed railway.

• Asian-Australasian Journal of Animal Sciences
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• 제22권12호
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• pp.1609-1613
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• 2009

The objective of this study was to estimate genetic parameters for racing performance traits of thoroughbredracehorses, using a total of 58,124 racing records of 4,200 horses at Gwacheon Racing Park collected from January 2002 to December 2006. This study measured start one furlong time, last three and last one furlong times, and the resulting furlong time averages were 14.2 seconds, 39.9 seconds and 13.9 seconds, respectively. Furlong time means a split time measured based on a 1/8-mile (or approximately 201 m) distance and finished time means total racing time measured from start position to finish line. In the shortest distance races of 1,000 m, the average last three and last one furlong time was fastest at 38.7 seconds and 13.6 seconds, respectively. The correlation between finished time and start one furlong time decreased as the race distance increased, and the same trend was recognized from the correlation between finished time and last three furlong time. In short distance races of 1,400 m or less, the starting ability was found to be an important trait. The average speed was highest at 56 km/h for a 1,000 m race and lowest at 53.2 km/h for a 1,700 m race. Heritabilities of the start one furlong time, the last three and last one furlong time were estimated to be 0.337, 0.245 and 0.210, respectively; and repeatabilities for them were 0.452, 0.353 and 0.309, respectively. Phenotypic and genetic correlations between the start and the last one furlong time were negative at -0.141 and -0.155, respectively.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.327-330
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• 2011

CFD simulation is widely used in various industries, universities and research centers. In Korea most of the researchers use foreign commercial S/W packages especially in industries. But commercial CFD packages have some problems as limit to source code and very high license foe. So from several years ago open source CFD code has been widely spread as an alternative. But in Korea there are a few users of open source code. Insufficiency of performance validation as for accuracy, robustness, convenience and parallel speed-up is important obstacles of open source code. So we tested some validation cases as to incompressible external aerodynamics and internal flaws and now are doing compressible flaws. As the first stage of compressible flow validation, we simulated Korea next generation high speed train(HEMU). It's running condition is 400km/hr and maximum Mach number reaches up to 0.4. With the high speed train we tested accuracy, robustness and parallel performance of open source CFD code OpenFOAM Because there isn't experimental data we compared results with widely used commercial code. When use $1^{st}$ order upwind scheme aerodynamic forces are very similar to commercial code. But using $2^{nd}$ order upwind scheme there was some discrepancy. The reason of the difference is not clear yet. Mesh manipulation, domain decomposition, post-processing and robustness are satisfactory. Paralle lperformance is similar to commercial code.

• 한국철도학회논문집
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• 제16권1호
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• pp.40-46
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• 2013

국내 철도노반설계기준에는 강화노반 두께를 일반철도와 고속철도로 이원화하여 규정하고 있으며 강화노반의 입도기준도 이원화되어 있다. 이로 인해 향후 기존선 속도향상 또는 유도상 궤도를 무도상 궤도로 변경 시 강화노반 두께증가 및 재료변경으로 인한 비용증가가 요구된다. 따라서 본 논문에서는 실대형 실험을 통하여 노반상태 변경 없이 기존 일반철도인 유도상 궤도를 무도상 궤도로 변경하고 동일선로에서의 열차속도 향상 가능성을 검토하였다. 일반철도 설계기준에서 제시하고 있는 강화노반 두께를 20cm로 하고 강화노반 재료를 입도조정부순골재(M-40)를 사용한 선로 노반의 동적 특성을 분석하고 철도설계기준에서 제시하는 노반침하를 비교한 결과, 기존 일반철도 자갈궤도의 강화노반 두께 및 재료 변경 없이 무도상 궤도화가 가능하며 열차속도 400km/h까지 주행이 가능한 것으로 나타났다. 이러한 결과는 실내실험만의 결과이므로 추후 수치해석과 현장 실측치와의 비교 검토가 필요하다.

• 대한기계학회논문집A
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• 제36권8호
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• pp.929-934
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• 2012

본 연구에서는 레이저 TWB로 용접된 이종재료의 동적 특성에 대한 해석이 수행되었다. 해석프로그램은 Hyper works 10.0으로 Solver는 LS-DYNA v.971, 모델링 요소는 2D-Shell, 요소 수는 35,641개, 노드 수는 36,561개이다. 충격속도는 10 km/h이다. 상 하부의 용접선 높이에 따르는 영향을 연구하기 위하여, 하부의 길이를 300 mm와 400 mm로 하였다. 얻어진 결론은 다음과 같다. 길이 300 mm인 하부 재료 SPFC980의 변형은 가장 작고, 충돌 흡수 에너지는 가장 크다. 하부 냉연강 기준으로 TWB의 위치가 짧을수록 성능이 우수하게 나타났다. 즉, 상대적으로 상부 고강도강인 SABC1470 재료가 차지하는 비율에 따라 성능이 좌우되었다. 하부 재료 SPFH590은 큰 변형이 나타났고, 충돌성능은 SPFC980보다 현저히 떨어졌다. 따라서 충돌 성능 해석 결과에서 하부 재료 SPFC980인 길이 300 mm가 가장 우수한 것으로 나타났다.