• Journal of Korea Society of Industrial Information Systems
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• v.19 no.3
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• pp.1-7
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• 2014

This paper describes the implementation of high speed comparator for the ATE (automatic test equipment) system. The comparator block is composed of continuous comparator, differential difference amplifier(DDA) and output stage. For the wide input dynamic range of 0V to 5V, and for the high speed operation (1~800MHz), high speed rail-to-rail amplifier is used in the first stage. And hysteresis circuits, pre-amp and latch are followed for high speed operation. To measure the difference of output signals between the two devices under test (DUTs), a DDA is applied because it can detect the differences of both common signals and differential signals. This comparator chip was implemented with $0.18{\mu}m$ BCDMOS process and can compare the signal difference of 5mV up to the frequency range of 800 MHz. The chip area of the comparator is $620{\mu}m{\times}830{\mu}m$.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1595-1600
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• 2004

High speed railroad project management has been almost completed by starting operation of Seoul-Busan high speed railroad with the exception of a few constructing blocks currently in April, 2004. After Korea Rail Network Authority was established in 2004, it needs to develop new project management system for both conventional railroad construction and high speed railroad construction for domestic railroad projects, while it plans to invest in overseas railroad project for logistics innovation and improvement in passenger transport services on a large scale. Therefore this paper provides the method that we can adapt the project management system for high speed railroad containing experiences and know-how from construction of high speed railroad for both conventional railroad construction and high speed railroad construction or improve project management system for high speed railroad to use it as project management system for overseas railroad projects.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.513-515
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• 1995

A computer aided process is inevitable for the optimization of train operation planning. Developing of train diagrams is very important for the train operation planning. In this paper, the user friendly program related to the train scheduling that can be used for the basic data on developing of train diagram is introduced. It can also provide basic data for other train operation plannings, such as Timetabling, Crew Operation Scheduling, etc. It provides the planner with data moving, data changing and zooming functions, and it can assist the user easily produces their optimal solution. All this operations are performed interactively through graphic windows.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.12-15
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• 2005

In April 1, 2004, age of high-speed railway was opened to korea railroad. The railroad is a means of large transportation which has many talents such as a safety and a regularity. That is a results from various confidential performance tests and evaluations of the system. The railroad system consist of various subsystems - vehicle, power supply, signal, communications, track structures, operations, etc. Among them, as an item of safety evaluation there is a measurement of wheel/rail farce, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more important in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, examined speed elevation possibility use the korean style high speed railway vehicle for reduce the running time of high-speed railway between high speed line and conventional line.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.4
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• pp.1261-1267
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• 2014

It is generally recognize that the weight of energy cost for railroad alignment in the life cycle cost is higher than that for roadway. This study analyzed the relative weights of railroad road-bed construction cost and energy cost in the case of Seoul-Pusan High Speed Rail. Recently, the optimization of railroad alignment with computerized methodology has been studies. The optimization is supposed to aim the minimization of life cycle cost including the energy cost as well as the minimization of the construction cost. The operation period of the Seoul-Pusan High Speed Rail is limited to ten years, then various future operation scenario were developed for the next 20 years. The weight of energy cost is estimated 10~30% of the construction cost by scenario, and it is lower than the figure generally expected. It may be meaningful to provide the method to include the energy cost in the railroad alignment optimization.

• Journal of the Korean Society for Railway
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• v.7 no.4
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• pp.374-390
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• 2004

In this paper, I illustrate the situations and problems rail industry is faced with. The rail industry has been suffering deficiency in investment with low technical level. Lacks of strategic marketing plans and low competitiveness in the industry led to a small portion of modal share, estimated at 12.6% in 2001(person base). Recently, rail industry has caught up with the current flow of changes. For example, a prototype of Korea high speed train had been manufactured to be successfully tested on commercial track. And the amount of rail investment increased gradually. The rail industry of EU nations, America, Japan reveals good outcomes, which keeps the balance in the black thanks to growth of investment in rail and high technical level. I have come up with some ideas for improvement, which I believe will be helpful to lead the rail industry. First, I suggest the upbringing of rail industry and technology on a national level. Second, expanding the rail network with the rail modernization. Lastly, I think it is crucial to establish a law and institution before we advance into overseas markets.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.23 no.7
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• pp.605-616
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• 2013

An important source of noise from railways is rolling noise caused by wheel and rail vibrations induced by acoustic roughness at the wheel-rail contact. In the present paper, characteristics of rail vibration and radiated sound power from concrete slab tracks for domestic high speed train(KTX) is investigated by means of a numerical method. The waveguide finite element and boundary element are combined and applied for this analysis. The concrete slab track is modelled simply with a rail and rail pad regarding the concrete slab as a rigid ground. The wave types which contribute significantly to the rail vibration and radiated noise are identified in terms of the mobility and decay rates. In addition, the effect of the rail pad stiffness on the radiated power is examined for two different rail pad stiffnesses.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.673-678
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• 2013

Driving gear units can be affected by various problems, including those associated with external or internal defects in the bearing, problems with the lubricant oil, high-loading of the railway, and frequent impacts generated by rail joints. Temperature monitoring is a basic method in diagnosing abnormal conditions in the reduction gear and other components. This paper describes a new wireless monitoring system for the temperature diagnosis of abnormal conditions of the reduction gear. Integrated circuit (IC)-type temperature sensors were installed in the reduction gear box of a high-speed railway car. The temperature data from the reduction gear were acquired and analyzed in situ during high-speed rail operation. Analysis of these data was used to alert the driver and/or maintenance personnel when problems occurred.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1312-1319
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• 2006

Several countries including Korea, Japan and European countries have reached the stage of planning, constructing their high-speed railway systems. High-speed train will become a key tool for intercity passenger transportation. Before that, safety of high-speed train must be secured. It is connected directly with track. The track is composed of ballast, tie, fastening and rail. Also, the fastening system makes tie and rail connect. In this case of the railway bridges used concrete slab track, the deflection of the bridge cause uplife of the rail at the areas between segments. In the structural analysis about it, stiffness of the fastening systems has been assumed. Therefore, use of the stiffness according to an experimental study needs. In this study, the stiffness values of various types of fastening systems are determined by the experiment and the structural behavior of fastening system is analyzed.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.479-487
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• 2004

The Korean railroad has developed as a foundation of nation's nucleus network. Nowadays Korea has entered into a new era because of the operation of KTX(Korea Train Express). As an introduction of KTX, the Korean railroad system has advanced Korean style high speed rail(HSR-350x), which is based on transfer and own technology. It is expected that the Korean rail road system has the leading design and production ability. Korea is planning to develop its own high speed railroad system until 2007. So the present task is to initiate a strategic export method for the development and value-added of Korean high speed railroad system. Furthermore this study proposes the administrative and technical policy for the basic technical research and creativeness predominance.