• 대한기계학회논문집B
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• 제28권8호
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• pp.984-988
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• 2004

This study presents the process of the solenoid parameter estimation of an common-rail injector fer HSDI(High Speed Direct Injection) diesel engines. The EMF(Electromotive Force) and solenoid inductance are the major parameters for presenting the injector dynamics, and also these parameters are estimated by using a multi-layer feedforward artificial neural networks(ANN). The performances of parameter estimators are verified by the simulation with injector model. The feasibility of this methodology is closely examined through the simulation in the various operating points of injector. The simulation results have revealed that estimated parameters show favorable agreements with the common-rail injector model.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.432-441
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• 2007

Any track system needs major changes of its components during its life. The most economical solution is, if possible, to make all components reach their life limit during the major track rehabilitation operation. Usually, the rail does a role as the driving component for the objective: its life-time is equivalent to around 500 million tons of traffic on high speed lines. On the KTX line with 110 trains per day, this would correspond to around 16 years, which is probably too long for the elastic pads of a concrete slab track. The most economical solution should be to change them at an intermediate step of 8 years, without changing the rail, and then to change both the rail and elastic pad at 16 years intervals (some rail changes on the South East TGV line in France began 15 years after service opening at 260 km/h, but recent rails have better characteristics).

• 한국소음진동공학회논문집
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• 제14권10호
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• pp.999-1006
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• 2004

Recently, the ride comfort problem becomes increasingly important because of today's needs for train speedup. The railway has the track irregularities which cause vibrations, such as rail joints, turnout, level crossing, transition corves and super-elevation ramps, and variations in the track level(z-axis) and the gauge(y-axis). In Korea, the service run of the high speed train has been made since the 1st of April, 2004. The commercial high-speed trains must be run on the compound lines which are composed of high-speed line and conventional line. The high speed lines in both Kyoungbu line and Honam line have 57.5％ and 33.8％, respectively In this Paper, the ride comfort has been reviewed by the various experimental methods when the high-speed trains are operated on both Kyoungbu line and Honam line. The results show that the high-speed train has no problems from the viewpoint of the comfort ride during the operation on the high speed line and conventional line.

• 소음진동
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• 제11권2호
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• pp.354-364
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• 2001

The vibration induced by high speed train running on rail is dealt with as an environmental problem. The train induced vibration is characterized by moving loads at specific frequencies and soil conditions. In fact, it is predicted that the vibration sources are involved the wheel distance, number of cars, speed of operation, drift of rails, structural born vibration, etc. In this paper the characteristics of transferring vibration induced by the high-speed train in operation is discussed. Field measurements was conducted at region from Chungnam Yungj So-jung-myan to Chungbuk Chungwon hyun-do-myun. In the near future. these data will be used as the fundamental data for establishment of the countermeasure for vibrational reduction of high speed train using the results of the field measurements and quantitative prediction of the vibration level

• 한국음향학회지
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• 제33권4호
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• pp.238-247
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• 2014

본 논문에서는 철도 전동 소음의 주요 소음원인 레일 소음의 방사 특성을 이론적으로 해석하고 배열 마이크로폰을 이용한 레일 소음 측정 시 발생하는 현상들에 관해 이론적으로 고찰하였다. 철도 궤도는 국내 고속철도 콘크리트 도상 궤도를 대상으로 하였으며, 레일에 고속의 이동 하중이 작용하는 경우에 대한 진동 및 소음 방사 특성을 해석하였다. 본 연구를 통해 이동 하중이 작용할 때 발생하는 레일의 소음 방사 특성을 파악하였으며, 배열 마이크로폰을 이용한 레일 소음 측정시 빔 각도가 배열 마이크로폰 출력 음압에 중요하게 작용함을 확인하였다. 따라서 배열 마이크로폰을 이용해 레일 소음을 규명하기 위해서는 레일의 방사 특성을 반영한 배열 마이크로폰 빔 각도 설정이 필요함을 이해하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.340-350
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• 2007

The major objective of this study is to investigate the fatigue effects of rail pad on High Speed Railway with concrete slab track system. It analyzed the mechanical behaviors of HSR concrete slab track with applying rail pad stiffness based on fatigue effect(hardening and increasing stiffness) on the 3-dimensional FE analysis and laboratory test for static & dynamic characteristics. As a result, the hardening of rail pad due to fatigue loading condition are negative effect for the static & dynamic response of concrete slab track which is before act on fatigue effect. The analytical and experimental study are carried out to investigate rail pad on fatigue effected increase vertical acceleration and stress and decrease suitable deflection on slab track. And rail pad based on fatigue effect induced dynamic maximum stresses, the increase of damage of slab track is predicted by adopting fatigue effected rail pad. after due consideration The servicing HSR concrete slab track with resilient track system has need of the reasonable determination after due consideration fatigue effect of rail pad stiffness which could be reducing the effect of static and dynamic behavior that degradation phenomenon of structure by an unusual response characteristic and a drop durability.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.114-119
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• 2008

A refined three-dimensional finite element interaction model between the high-speed train and railway bride deck has been developed in the present study. Analytical predictions of vertical deflections for a railway bridge are compared with in-situ test results and a good agreement is achieved. Then, input variables employed in the analytical comparisons are selected as random variables for the limit state functions. followed by risk assessment. For this purpose, a linear adaptive weighted response surface method has been developed and applied. A typical railway bridge has been selected and the limit state functions are employed from UIC and Korean specifications in the comparative studies. The results reveal that Korean specifications give significantly risky reliability indices in comparison with UIC specifications. It is thus encouraged from the above that the present linear adaptive weighted response surface method can be an alternative for the fast estimation of nonlinear structural systems.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.110-115
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• 2002

In this paper, the results of an analysis of the dynamic behavior of the eddy current brake(ECB) system are presented. The measured irregularity of the track in Korean high speed line and the track irregularity given by ERRI(high level) were used for simulation. The wheel-rail profile combination were analyzed with different rail gauges. A model of the bogie with an substitute body for the carbody was implemented in the Multi-body-Simulation Program SIMPACK. The ECB frame was modelled both as flexible body and as rigid body. Four different driving conditions were analyzed. In this study dynamic behavior in general were performed to evaluate the design of eddy current brake system and specially the effect of damper was also studied. A comparison of simulations with and without damper shows that the damper have most effect for lower speed. The simulation results will be verified by comparison with measured data from on line test and also used for improving design.

• 대한교통학회:학술대회논문집
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• 대한교통학회 2003년도 제43회 학술발표회논문집
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• pp.127-150
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• 2003

This research presents a novel application of static traffic assignment methods, but with a variable time value, for estimating the market share of a high-speed rail (HSR) in the NW-SE corridor of Korea which is currently served by the airline (AR), conventional rail (CR), and highway (HWY) modes. The proposed model employs the time-space network structure to capture the interrelations among all competing transportation modes, and to reflect their supply- and demand-sides constraints as well as interactions through properly formulated link-node structures. The embedded cost function for each network link offers the flexibility for incorporating all associated factors, such as travel time and fare, in the model computation, and enables the use of a distribution rather than a constant to represent the time-value variation among all transportation mode users. To realistically capture the tripmakers' value-of-time (VOT) along the target area, a novel method for VOT calibration has been developed with aggregate demand information and key system performance data from the target area. Under the assumption that intercity tripmakers often have nearly "perfect" travel information, one can solve the market share of each mode after operations of HSR for each O-D pair under the time-dependent demand with state-of-the-art traffic assignment. Aside from estimating new market share, this paper also investigated the impacts of HSR on other existing transportation modes.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2076-2081
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• 2004

Future exhaust gas limits for diesel-driven passenger cars will force the automotive industry to significantly improve the performance of engine. Since modern common-rail injection systems deliver more degrees of freedom referring to the injection process, again the optimization of the injection process could offer a possibility to meet the exhaust gas limits. This study describes the characteristic the pilot spray structure of piezo-driven injector for a passenger car common-rail system to be applicable multiple injection caused by fast response rather than solenoid-driven injector. The piezo-driven injector is prototype injector with same needle chamber of solenoid injector and the solenoid-driven one is commercial injector. The pilot spray characteristic such as spray tip penetration, spray speed, spray angle were obtained by spray images, which is measured by the Mie scattering method with optical system for high-speed temporal photography. It was found that piezo-driven injector effected electric change as important factor and showed faster response than solenoid-driven injector.