• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1689-1694
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• 2011

There are increasing customer's needs for safe operation and comfort of trains for the passengers as trains are getting fast and developed with advanced components. To meet the needs we developed the system which is able to prevent possible risk elements by transverse vibrations during the train operation. System records the amplitude data of trains vibration and location data from GPS antenna in real time. The system is composed of 5 different functioning modules as following GCPU, GGWD, GIFD, GAID and GPSD. GAID module is detecting amplitude value of vibration which is sensed by bogie hunting sensor's. GFID gets location information where vibration data is detected with GPS Antenna. Once those data is prepared, GCPU testify it's amplitude and decides whether it send those data. When it sends those recorded data, those data are sent to control unit by MVB communication. we expect that this information will help operation and maintenance engineers improve the safety train services. This paper explains train transverse Vibrations data recording system and its major functions which can measure the amplitude of trains's data during the operation and introduces the configuration for the system setup.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.830-835
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• 2011

DMT Freight is judged that economic performance is good because can increase cargoes than existing freight. However, the existing freight cars, each with a different balance to the body structure is bogie because the vibrations may occur. Thus, by minimizing vibration over the existing freight securing the safety of the driving if you will not have major problems in cargoes. In this study, multi-body dynamic analysis tool, VI-Rail using the actually Gyeongbu Railroad line and an empty, full freight condition include curve radius, track irregularity, cent. DMT freight of the derailed wagons were assessed for safety analysis. Full and empty freight conditions for parity in the Gyeongbu Railroad line(Dongdaegoo ${\leftrightarrow}$Gyungsan) derailment safety analysis, such as derailment safety coefficient and the radius wheel road decrement, echoing the curve and the orbit is affected by the irregularity was found. Full freight condition than the empty conditions showed a significant derailment safety. Overall, the limits of derailment coefficient (Q/P=0.8) and wheel road decrement limits (${\Delta}P/P=0.6$) is less safe with me confirmed that the derailment safety.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.4
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• pp.266-273
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• 2003

The purpose of this study is to obtain the effects of the parameters of the suspension system in railway rolling-stock for KT-23 type Passenger vehicle. According to the analysis and the small scale model car test. optimal condition was obtained for the stiffness ratio of secondary spring to primary spring of the suspension system and the mass ratio of the bogie frame to the car body. The analysis of the study shows that if the car body mass is increased or secondary stiffness Is lowered, the vertical vibration level is reduced and the passenger comfort can be improved. Especially, strong peaks are occurred in the frequencies corresponding to the rotational speed of driving axle and vehicle wheel. Hence, in order to obtain the dynamic characteristics through the small scale model car, the driving method of the vehicle on the test bench, rotational characteristics of the wheel and the natural modes of vehicle should be investigated and be modified.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.3081-3083
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• 2005

한국형 고속전철차량의 자동제어 구현을 위해서 우선 다양한 종류의 장치들로부터 상태정보(Line Voltage-열차가선전압, Bogie Hunting, Preset Speed, PWM, Train Velocity, Brake Pressure, Reservoir Pressure)를 취득해야하며, Main Process Unit(MPU)에서의 고속 Data 처리를 위해서 취득한 Analog Data를 신속하게 Digital Data로 변환해야 한다. 또한 열차내의 특수한 조건(Noise, Vibration)에서도 안정적인 데이터의 취득을 만족시켜야한다. 이와 같은 상황을 고려한 독자적이 통합형 데이터 취득 장치 -Integrated Data Acquisition Board(IDAB)-의 설계방안을 제시하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.3 s.174
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• pp.661-666
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• 2000

Optimization of the elastic joint of train is performed according to the minimization of ten responses which represent driving safety and ride comfort of train and analyzed by using the each response se surface model from stochastic design of experiments. After the each response surface model is constructed, the main effect and sensitivity analyses are successfully performed by 2nd order approximated regression model as described in this paper. We can get the optimal solutions using by nonlinear programming method such as simplex or interval optimization algorithms. The response surface models and the optimization algorithms are used together to obtain the optimal design of the elastic joint of train. the ten 2nd order polynomial response surface models of the three translational stiffness of the elastic joint (design factors) are constructed by using CCD(Central Composite Design) and the multi-objective optimization is also performed by applying min-max and distance minimization techniques of relative target deviation.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.194-200
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• 2007

The tilting train is able to tilt its body towards the center of the turning radius, preventing roll-over of the train as it runs on a curved rail at high-speed. This train, widely accepted for commercial purpose internationally is very beneficial in that the operating time is shortened without much capital investment to the infrastructure where there are many curved rails. Over several years, the Korea Railroad Research Institute(KRRI) has developed such a train. In this paper, the safety of the Korean tilting train express(TTX) is investigated using a dynamic simulation model. Since, proper safety standards have not been established for the TTX, those for the Korean train express(KTX) is employed instead to analyze the safety and ride comfort of the TTX. This study will prove useful in predicting the behavior of the TTX and ride comfort, and conforming that designed TTX measures up to the safety standards. It would be useful to recommend proper normal operating speed and determine the maximum safety speed, according to the result. Furthermore, it would be possible to provide basic reference data when analyzing the dynamic effect of the catenary system and the fatigue of the bogie.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.65-70
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• 2007

Welding is the most commonly used method to produce bogie and carbody of Electrical Multiple Units(EMU), because it increases the strength and lowers the weight of EMU. Since bogies are constantly exposed to repeated reacting load during acceleration and deceleration, it is also true that crack normally occurs at welding parts. In this study, we have investigated the fatigue strength of SS400 on welded parts in order to find efficiency of treatment after welding by shot peening and Post-Weld heat treatment(PWHT) with butt welded specimens. The results of fatigue test indicate that the measurement of base material specimen is 236MPa, welded specimen is 132MPa and the specimen of PWHT is 107MPa approximately. We concluded that the measurement of welded specimen and PWHT is approximately 44 and 54 percents lower than the base material specimen, respectively. Another finding is that the peened specimen is approximately 23 and 61 percents higher than the base material specimen in terms of the fatigue in strength of specimens.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.567-573
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• 2003

Korean High Speed Train (KHST) has been tested on high speed line in JungBu site since it was developed in 2002. The data acquisition system was developed to accomplish successfully this on-line test for proving the dynamic Performance of KHST. This system was consist of the personal computers based on National Instrument PXI modules and the test programs based on Labview 6i. This paper shows that this system is efficient to acquire the test data through the multi-channels connected the accelerometers which located in long distance places and flexible to change and add channels for data acquisition. The dynamic analysis of an on-line test is very complicate because the environmental conditions, as examples radius of curve, inclination of the track, tunnels, bridges, and so forth, and running conditions, as examples driving, braking, the number of working motors, and so forth, have an effect on the results. Therefor, the analysis method is important and this paper proposes the efficient procedure graphically, showing the proposed method simplify the accelerations of 5th bogie frame acquired during the on-line test for KHST.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.7
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• pp.637-642
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• 2011

The DMT freight is judged that economic performance is good because can increase cargoes than existing freight. However, the existing freight cars, each with a different balance to the body structure is bogie because the vibrations may occur. Thus, by minimizing vibration over the existing freight securing the safety of the driving if you will not have major problems in cargoes. In this study, multi-body dynamic analysis tool, VI-Rail using the actually Gyeongbu Railroad line and an empty, full freight condition include curve radius, track irregularity, The DMT freight of the derailed wagons were assessed for safety analysis. Full and empty freight conditions for parity in the Gyeongbu Railroad line(Dongdaegoo${\leftrightarrow}$Kyungsan) derailment safety analysis, such as derailment coefficient and the wheel unloaded, echoing the curve and the orbit is affected by the irregularity was found. Full freight condition than the empty conditions showed a significant derailment safety. Overall, the limits of derailment coefficient(Q/P = 0.8) and wheel unload decrement limits(${\triangle}P/P$ = 0.6) is less safe with me confirmed that the derailment safety.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.32-38
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• 2020

Cargo train braking uses the pressure changes in the air braking pipe to operate the braking tightening and releasing service repeatedly. Air-braking release failure means partial braking caused by a failure of the variable load valve after the driver handling the brake release. This phenomenon causes wheel flaws while driving a wagon, resulting in wheel breakage or train derailment. This study developed the air-braking release failure proof valve considering the technical requirements of the railway operation corporations. In addition, a durability test of the valve was carried out using a braking performance simulator, and its operating performance was evaluated from the pneumatic history under cyclic braking conditions. The warranty life of this valve was assessed by performing 160,000 cycles of testing of 12 prototypes in accordance with the zero-failure test method, considering the number of braking cycles while driving the wagon. During the durability test, the pneumatic input time, output time, and release velocity were almost constant. The warranty life of this valve was 59,860 times the 95% confidence level, which means that it can be operated without trouble for four years when the valve is installed in the bogie of the wagon.