• Journal of the Korean Society for Railway
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• v.18 no.1
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• pp.43-52
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• 2015

In this study, to minimize both the costs associated with track maintenance and the energy consumption for train operation, a numerical method that evaluates the optimal vertical stiffness of a fastener for concrete track is presented. A progress model of the track damage is established in order to calculate the concrete track maintenance cost according to the fastener stiffness. Also, the quantitative relationship between the progress of the track damage and the maintenance of the concrete track is derived. The wheel load is more exactly evaluated by using the advanced vehicle-track interaction model, which can precisely consider the behaviors of the track components. An optimal range for the stiffness of the fastener, a range that is applicable to the design of concrete track for domestic high speed lines, is proposed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.15 no.1 s.94
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• pp.29-38
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• 2005

The track pull-in behavior analysis in an optical disk drive (ODD) using plane phase and the evaluations for effecting parameters of it are discussed. Track pull-in, track capture procedure to do track following control, is a key factor to increase data transfer rate. First, the relative velocity between the beam spot of an optical pick-up and the target track of an optical disk is analyzed during the track pull-in procedure. In this process, it is showed that the track error signal has nonlinear characteristics which are depending on the time. Second, Runge-Kutta method to solve the nonlinear equation is applied to find the track pull-in behavior, and some optimal parameters to get stable and fast pull-in condition are obtained. Then, the phase plane analysis for track pull-in procedure is presented. Finally, some comments for the simulated results are discussed briefly.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.717-724
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• 2006

The major objective of this study is to investigate the effects and application of improvement for railway steel plate girder bridge by resilient panel track system. It analyzed the mechanical behaviors of steel plate girder bridge with applying resilient panel track system on the finite element analysis and laboratory test for static & dynamic characteristics. As a result, the improvement of steel plate girder bridge with resilient panel track systems are obviously effective for the static & dynamic response which is non-ballast steel plate girder bridge. The analytical and experimental study are carried out to investigate resilient panel track system decrease vertical acceleration and deflection on steel plate girder bridge for serviceability. And the resilient panel track system reduced dynamic maximum displacements (about 59%) and stresses (about 82%), the increase of dynamic safety is predicted by adopting resilient panel track system. From the dynamic test results of steel plate girder bridge, it is investigated that vertical acceleration and deflection is very low with applying resilient panel track system. The servicing steel plate girder bridge with resilient panel track system has need of the reasonable improvement measures 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.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1864-1874
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• 2007

Korean trains pass many mountain areas, so the volume of structures like bridge and tunnel has large part of railway lines. Train speed-up naturally needs a straight line in railway, then structures are increasing, and the length of structure has more than 70% in Kyongbu high-speed railway. The stiffness of bridge and tunnel is higher than the soil in the roadbed in spite of dynamic difference in vibration and displacement. Differences in stiffness have more dynamic effects and increase the deformation and destruction in the track and roadbed. This influences passenger's comfort and the safety of operation, and it needs more track maintenance. This study selected tunnel with ballast track, tunnel with concrete track, and structure's approaches with short maintenance cycle in the roadbed and had track acceleration tests and track liner inspections using track master in the field. This study will measure periodically to structure's approaches which have very fast track irregularity and analyze dynamic differences and track irregularity near structure's approaches, so realize the cause of track irregularity of structure's approaches and use basic data for reasonably strengthening method of structure's approaches.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1223-1228
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• 2007

Since KHSL 2nd phase was adapted as a main track design, the interests of concrete slab track system have been gradually increased in the division of rail track engineering and many engineering companies have been trying to adapt a concrete slab track system at this moment. Advantages of this system proved in advanced country, japan and Germany etc. are excellent maintenance, track stability and increasing of buckling resistance This developed turnout is same with the KHSR 1st phase's design and applications rules, components and signaling system since it observes KTX specification. Comparing it with the former turnout, High-elasticity pad, lubrication-free roller slide plate and Rheda2000 PC sleeper are only different. The purpose of this study is the development of high speed turnout on concrete slab track and its application on site. Now these studies are going to show the verification and confidence about the interface between ballast-track and concrete slab track by finding and solving the possible problems when it is installed on site and to make these turnouts applied perfectly and completely on concrete slab track. Its first trial construction in korea had been successfully completed at Sangju-station on July 20th ,2007 thanks to KORAIL and KR. Hereunder Sampyo E&C trys to introduce all of turnout technologies on concrete slab track system with Rheda 2000 sleeper

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1647-1652
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• 2008

Track geometry consists of tangent and curved lines, which caused undesirable changes in initial track geometry by traffic loads. The bigger the changes are, the worse the riding comfort and running stability of train. This is so-called track irregularity and is the most important quality parameters of ballasted track. To be able to objectively assess track irregularity, track geometry should be able to be measured. Practically, railway companies use moving chord method, this method determine versine values via a chord. The versine is the vertical distance to curve measured in the middle of the chord. This type of method measures only versine of track irregularity curve by transfer function from specific property of measuring tool. In this report, review the characteristics of two types of measuring tools by comparing the measurements. The one is GRP-1000 system, optical surveying system with Total station and lazar prism trolly. This calculates track geometry by surveying absolute coordinates of two points each on both rail heads. The other is Trackmaster, measures versine with 2m of chord length.

• Journal of the Korean Geotechnical Society
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• v.21 no.5
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• pp.163-170
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• 2005

Track substructure (ballast, subgrade) should have sufficient strength and uniform stiffness to fully support track superstructure (rail, fastener, sleeper). Vertical support stiffness of track is strongly influenced by the condition of ballast and subgrade layers. Therefore, the evaluation of the condition of track substructure is very important to evaluate the vertical support stiffness of track. This paper proposes the trackbed evaluation system, which is composed of Ground Penetrating Radar (GPR), Portable Ballast Sample. (PBS), and Light Falling Weight Deflectomete. (LFWD), to diagnose track substructure. The laboratory and field tests are performed to evaluate the applicability of the proposed trackbed evaluation system.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.437-446
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• 2006

The major objective of this study is to investigate the effects and application of improvement for railway steel plate girder bridge by resilient panel track system. It analyzed the mechanical behaviors of steel plate girder bridge with applying resilient panel track system on the finite element analysis and laboratory test for static & dynamic characteristics. As a result, the improvement of steel plate girder bridge with resilient panel track systems are obviously effective for the static & dynamic response which is non-ballast steel plate girder bridge. The analytical and experimental study are carried out to investigate resilient panel track system decrease vertical acceleration and deflection on steel plate girder bridge for serviceability. And the resilient panel track system reduced dynamic maximum displacements(about 59%) and stresses(about 82%), the increase of dynamic safety is predicted by adopting resilient panel track system. From the dynamic test results of steel plate girder bridge, it is investigated that vertical acceleration and deflection is very low with applying resilient panel track system. The servicing steel plate girder bridge with resilient panel track system has need of the reasonable improvement measures 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3319-3325
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• 2012

This paper describes the development of the TrackSim, which is a discrete event simulation tool for photolithography equipment of semiconductor industry. The TrackSim is focused on the accurate simulation model of the photolithography equipment and easy-to-use user interfaces. TrackSim provides 3D simulation environment for evaluating, validating, and scheduling the photolithography process. One of the major characteristics of TrackSim is in that it is developed based on Applied Materials' AutoMod, a discrete event simulation software broadly used in semiconductor industry. Accordingly, the photolithography model of TrackSim can be used to perform simulation connected with other simulation models built with AutoMod.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.379-384
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• 2009

It is of great importance to assure the running safety and ride comfort in designing the floating slab track for the mitigation of train-induced vibration. In this paper, for this, analyzed are the system requirements for the running safety and ride comfort, and then, the behavior of train and track at the transition zone between the floating slab track and the conventional concrete slab track according to several main design variables such as spring constant, damping coefficient, spacing and arrangement of isolators and slab length, using the dynamic analysis technique considering the train-track interaction. The results of numerical analysis demonstrate that the discontinuity of the support stiffness at the transition results in a drastic increase of the vertical vibration acceleration of the train body, wheel-rail interaction force, rail bending stress and uplift force. The increase becomes higher with the decrease of the spring constant of isolators and the increase of the isolator spacing, but the damping ratio does not significantly affect the behavior of train and track at the transition. Therefore, to assure the running safety and ride comfort, simultaneously increasing the effectiveness of vibration isolation, it is effective to minimize the relative vertical offset between the floating slab and the conventional track slab by adjusting the spring constant and spacing of isolators at the transition.