• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1835-1840
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• 2010

The rolling stock have to be tested and evaluated on test line before entry into service. The test items consist of traction performance, braking performance and current collection performance, etc. This paper is a study of defining the test items considering the domestic safety law, IEC 61133 and describes how to establish a test measurement system. Also this paper presents how to conduct the traction performance test and test results.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.174.3-174
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• 2001

Electric power collection is one of the most important factors for the high-speed trains' operation. For the stable current collection, the contact wire of a catenary and the panhead of a pantograph should maintain a constant contact each other. In this paper, the catenary was modeled as a spring with time-varying stiffness from the point of a pantograph moving along the catenary, and the pantograph was modeled as a 3-D.O.F. mass-spring-damper system. Using the adaptive control method, the desired control performance could be obtained with the modeling errors and the time varying parameters. Also the state estimator was used considering the difficulty of applying the sensors obtaining feedback signals. Simulations were accomplished in various ...

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.1223-1225
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• 2001

This paper describes the simulation algorithms and user interfaces of the self-developed CaPoDyS which is to simulate the dynamic interaction between catenary and pantograph based on FEM. Also, the reliability of the simulation results are discussed through comparing with the ERRI report.

• Proceedings of the KSR Conference
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• 2000.05a
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• pp.606-617
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• 2000

A dynamic simulation program for pantograph-catenary system is developed based on a mode superposition method to predict current collection performance. Formulations for the dynamic simulation are presented in this paper. The number of modes which should be considered for a KTX catenary system is reviewed through frequency response analyses. The responses for GPU pantograph - KTX catenary system are simulated with various train speeds. The our simulation results are in reasonably good agreements with RTRI simulation program, SNCF simulation program, and BR simulation program.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.849-852
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• 2002

Recently, amorphous selenium is used as x-ray conversion material for flat-panel x-ray detector. In this paper, we investigated the effect of breakdown under high voltage and leakage current in PN-type multi-layer structure based on p-type a-Se and n-type conductive thin film. Experimental results show that the multi-layer based detector reduced leakage current because n-type CeO2 conductive layer prevent from hole injection into a-Se layer from collection electrode, Also, the breakdown voltage was improved by dielectric layer between a-Se and top electrode.

• Journal of the Korean Society for Library and Information Science
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• v.41 no.1
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• pp.323-344
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• 2007

This study was carried out for extension of SOMS as metadata of KERIS dCollection to activate IR(institutional repository), which was a new media for academic communication. For this study, current trends of foreign IR were surveyed, and MIT Dspace metadata and Bruxel DISpace metadata were analyzed to apply to SOMS. New SOMS suggested in this study will be more flexible to describe various materials, and to import and/or export academic research performance metadata.

• Journal of Biosystems Engineering
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• v.36 no.3
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• pp.204-210
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• 2011

This study developed the cyclone conveying system using roughage cutter for the round bale reported in the previous papers. Performance tests were conducted whether it can easily separate dust from roughage such as rice straws and it can transport roughages from cutter to TMR mixer. In addition, the airflow patterns in the cyclone conveying system were investigated using CFD code (FLUENT 6.2) for various velocities of dust collection fan. The cyclone conveying system was designed based on dried rice straws with a diameter of 1,340 mm, a cylinder length of 1,220 mm, a cone length of 850 mm and the current velocity of the dust collection fan was 15~20 m/s. It was found that transporting of roughage from cutter to TMR mixer and the separation of dust were satisfactory, and the dust removal rate of rice straws was around 31.9%. CFD analysis showed that, at the blowing fan velocity of 11.6 m/s, the airflow velocity inside the dust collector increased as velocity of the dust collection fan increased, but the airflow patterns inside the dust collector were all much the same.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.533-539
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• 1998

Described in this paper are the dynamic model and the dynamic performance of catenary-pantograph system for TGV-K(maximum operating speed of 300km/hr). Dynamic simulations showed that the system satisfies the performance criteria such as contact loss ratio, contact force and lift-off of the contact wire. It is also shown by the simulations that the dynamic behavior and contact performance of the system at the operating speed of 350km/hr are found unacceptable. Design parameters of the catenary-pantograph system should be optimized for the speed-up of the TGV-K.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.723-730
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• 2006

In the electrical railway, the tension ascension of contact wire is essential to speed up of train and current collection performance of catenary largely depends on the tension. The tension variation rate of the tensioning device used in existing line limits within 5%, and the tension variation rate of the spring-type tensioning device installed at the section where tensioning length is short bounds within 15%. So it is urgent for us to localize it for high speed line, which the tension variation rate is limited within 3%. Therefore in this study, a pulley-type tensioning device for high speed line is developed. To verify the performance of developed device, a performance test, overload test and failure test is carried out under the code of the Kyung-Bu High Speed line. And it is secured durability performance through a fatigue test.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.3
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• pp.94-105
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• 1995

Purposes of this study were to apply and examine that the importance-performance analysis(IPA) could be a useful park management tool. The IPA is an easily-applied technique developed in marketing field to measure attribute importance and performance. It displays them simultaneously on a 4-quardrant action grid; therefore, park managers can upgrade current services and address marketing strategies for various user segments. The children's grand park was selected as a study are. Two different types of questionaires were utilized for data analyses. They were collected from one respondent by on-site distribution or by mail survey, because attribute importance and performance should be rated before and after visiting a park, respectively. Then, total data was segmented systematically by 2 variables-age and benefit sought. Action grids from order to meet the needs of each segment. Several comments on both data collection methods and segment variables selection were described to improve the IPA in recreation settings for future researches.