• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.467-472
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• 2005

The characteristics of dynamic vibration are generally analyzed by an acceleration of a car body of high speed train and the acceleration can be applied to evaluation of running safety. The test of process and the analysis method about it are well explained on UIC Code 518 OR which is the spacial international standard about running safety and dynamic behavior on the line test for railway vehicle. Korean High Speed Train designed to operate at speed 350km/h has been tested on high speed line since it was developed in 2002 and it recorded the highest speed 352.4km/h at the 16th Dec. 2004 in Korea. This paper includes the analysis of running behavior of this train at speed 350km/h and also the analysis of dynamic safety is presented in it, extending to the range of high speed while the UIC 518 limit the speed below 200km/h.

• 한국염색가공학회지
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• 제9권4호
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• pp.28-38
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• 1997

Peach skin fabrics were washed by the general and ultrasonic washing systems using different conditions. The physical properties of the washed fabrics were estimated. The following results were obtained through experimental data and their analysis. The tensile properties were changed due to fabric running speed and washing methods. The lower the running speed, the higher the extensibility and resilience and the lower the linearity and tensile energy. In the general washing method, the extensibility and resilience had lower values than those of the ultrasonic washing method and the linearity and tensile energy had the higher values than those of the ultrasonic washing system. The bending properties, bending moment and histeresis, were estimated. These values were generally lower in the ultrasonic washing system than those of the general washing system. The faster the washing speed, the higher the value of hysterisis. The shear properties were affected by the fabric running speed and washing methods. Shear stiffness and hysteresis of shear forces increased according to the increase of the fabric running speed. The values were higher in the general washing system than those of the ultrasonic washing system. The compressional energy was affected by the fabric running speed. The higher the fabric speed the higher the compressional energy. The ultrasonic washing system had lower compressional energy than the general washing system. The higher the running speed, the lower the coefficient of friction and geometrical roughness. The values of geometrical roughness were infienced by the removal of the sizing agent. The higher the remaining sizing agent, the higher the fabric weight and the thicker the thickness of fabric.

• 한국철도학회논문집
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• 제10권5호
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• pp.473-479
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• 2007

KTX 인수시험 시 차량 후미부에서 횡진동이 발생하여, 차륜의 답면구배를 1/40에서 1/20로 변경하여 횡진동 문제를 해결하였다. 그러나 차륜의 답면구배를 변경하면 차량의 임계속도 및 주행 안전성에 영향을 미치기 때문에 1/20 차륜에 대한 주행 안전성에 대한 검토 요구된다. 본 논문에서는 VAMPIRE를 이용하여 KTX 1편성 20량을 모델화하여 주행 안전성 및 임계속도를 계산하였으며, 계산결과의 타당성을 검토하기 위해서 KHST차량의 시험결과와 비교하였다. 해석결과 차륜답면이 0.3인 경우 임계속도는 375km/h이상이었으며, 차륜의 답면구배가 1/20인 경우 1/40보다 곡선 추정성이 우수한 것을 알았다. 또한 기존선 주행 시 차량의 속도향상 가능성을 파악하기 위해서 계산한 결과 직선구간에는 10%속도 향상이 가능하지만, 곡선구간에는 기존차량의 속도와 동일하게 운행하는 것이 유리하다는 것을 알았다.

• 한국ITS학회 논문지
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• 제15권1호
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• pp.77-86
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• 2016

운전자는 다양한 종류의 교통정보를 여러 방식을 통해 받을 수 있지만, 인적요소를 고려한 정보 서비스는 이루어지지 않고 있다. 본 연구는 운전자 인적요소에 대한 기초 연구를 실행하기 위해 고속국도 주행 시 다양한 주행환경에서 속도의 차이에 따른 운전자 평균 주시시간의 특성 분석을 목표로 하였다. 분석 시 속도 외에 영향을 줄 수 있는 변수를 통제하기 위하여 주행상황을 '주간에 선행 차량 없이 주행', '주간에 선행 차량이 존재하는 상황에서 주행', '야간에 선행 차량 없이 주행', '야간에 선행 차량이 존재하는 상황에서 주행' 4가지로 분류하였다. ANOVA Test를 활용하여 속도 그룹을 나누었으며 그룹별 평균 주시시간의 차이를 비교하기 위해 다중비교(multiple comparison)를 한 결과 도로, 선행 차량 항목은 속도가 증가함에 따라 평균 주시시간이 증가하고 전경 항목은 평균 주시시간이 감소하는 것으로 나타났다. 도로표지 항목은 속도에 따라 주시시간의 차이가 통계적으로 무의미한 것을 확인할 수 있었다.

• 한국안전학회지
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• 제32권5호
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• pp.41-46
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• 2017

The coefficient of derailment and the rate of wheel load reduction were used as the index of train running safety that was directly affected the train derailment safety. In aspects of track, the train running safety depends on the complex interaction between wheel and rail, and the track-vehicle conditions (i.e., the curvature, cant, track system, vehicle speed and the operation conditions, etc). In this study, the relationship between the train running safety and the track curvature and vehicle speed for direct fixation concrete tracks currently employed in Korean light rapid transit was assessed by performing field tests using actual vehicles running along the service lines. The measured dynamic wheel load, lateral wheel load and lateral displacement of rail head were measured for same train running on four tested tracks under real conditions, which included curved and tangent tracks placed on the tunnel and bridge, thus increasing the train speed by approximately maximum design speed of each test site. Therefore, the measured dynamic track response was applied to the running safety analysis in order to evaluate the coefficient of derailment, the rate of wheel load reduction and the track gauge widening at each test site, and compare with the corresponding Korean train running safety standard. As the results, the lateral track response of direct fixation concrete track appeared to increase with the decreased track curvature; therefore, it was inferred that the track curvature directly affected the train running safety.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.345-350
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• 2005

KTX is the high speed train which is designed for 300km/h in maximum operation speed. But its long train set may cause unstable characters as swaying of the tail of a train and when the train is running on conventional line, its running safety is a point to be considered cautiously. In this study, we evaluated the running safety by the numerical analysis using VAMPIRE and compared the result with the test result of KHST, which is being in performance tests, for verifying the validity of analysis results

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.218-221
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• 2004

This Research is to test the running stability of the developed bogie with 350km/h of which conventional speed is faster than Korea TGV 300Km/h. The running stability test has been executed in status of a car with the developed bogie on the roller rigger to adjust similar to the actual condition. And the test has been done in the two rail conditions, i.e. excitation and non-excitation, respectively. Running speed of bogie increased by the roller step by step. In consequence, the developed bogie in the non-excitation has run without any unstable point for 400kn0h. Vibration characteristics of carbody also was within the value specified on the UIC 518.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1914-1921
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• 2011

When a railway vehicle passes through curves & transitions, the running speed must be improved by proposing the standards on the maximum running possibility speed of each section on conventional line (Dongdaegoo-Namsunghyun) considering derailment safety. In this paper, To improve the maximum running possibility speed of railway vehicle which passes through curves which have high risk of derailment, the track alignment conditions of conventional line (Dongdaegoo-Namsunghyun) that present transition curve length in current railway construction regulations are controlled. We presented elevation way about the section maximum running possibility speed in conventional line by analysis result.

• 한국공작기계학회논문집
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• 제11권2호
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• pp.65-70
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• 2002

The rotational performance off machine tool spindle has a direct influence upon the surface finish of the finished workpiece. This running accuracy of the spindle is improved by increasing preload on the bearings, while it results in higher temperature rise and larger thermal deformation. Therefore, finding the optimal preload condition for high speed spindle is very important factors in spindle motion. in spindle motion. In this study, the effect of the preload on the roundness accuracy has been examined at the different cutting conditions. Experiments were carried out to investigate the effects of the bearing preload on the running accuracy of high speed spindle which was supported by two angular contact bearings.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.477-482
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• 2003

The railway bridges on the new high-speed line are the first structures designed and constructed by our local engineers for high-speed running. In securing running stability and riding comfort in high-speed running, it is very important to verify the performance of structures and local specifications and design criteria by measuring and analyzing the dynamic behavior of main structural members. In this study, 4 different types(simple-span, 2, 3, 4-continuous spans) of PCS Box bridges on the test line(Yongwa$\~$Simok section) were selected, each representing a different type of superstructures, in order to verify the performance of the bridges by measuring dynamic responses during the test-run of KTX. Reviews of the running stability and the riding comfort were carried out with the results of the measurement and the analyses of vibration acceleration, endrotation, distortion and deflection at midspan.