• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1180-1184
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• 2004

There are two types of controller between railway and train. those are the Continuous Message Controller and the Intermittent Message Controller using for KHSR. The conventional Intermittent Message Controller board used a variable resister for setting the phase, but the variable resister affected some environmental facts, such as temperature, humidity, and vibration, etc. This study suggests how to solve the environmental problem described above. Using FPGA is quite profitable. It's easy to use and maintain, flexible with the New algorithm to fix up the problem.

• 대한전기학회논문지
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• 제43권7호
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• pp.1093-1102
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• 1994

PWM converters employing GTO's are proposed to be used for the currently planned Korean High-Speed Train system. In this paper, operating methods and harmonic spectrums are investigated for the PWM modulated voltage controlled GTO AC/DC converter used in the High-Speed Train System. It is shown that harmonic components can be controlled by varying carrier frequency in PWM modulation schemes. Then the input power-factor control scheme is suggested and analyzed. It is found that the power-factor can be varied by controlling the converter input voltage and phase angles between the input supply voltage and the converter input voltage. Finally, simulation programs are developed and converter systems are implemented.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2574-2577
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• 2008

The screw-feeders are used at gathering the minerals at the seafloor, transportation of the sewage, and at the beverage industry. This study was carried out to study solid-liquid mixture hydraulic transport of solid particles in a horizontal and inclined screw-feeders with rotating. This study is about the amount of the alteration amount of the material transportation for regular transportation. In this study a clear acrylic pipe was used in order to observe the movement of solid particles. Relates to the angle, rpm and ratio of pitch ; finding the optimum condition and knowing about designing the screw feeders shape. As a result, we found the suitable rpm and a suitable angle. According to the experiment, the best rpm and angle are 100-200rpm and $10^{\circ}$, respectively.

• Journal of Magnetics
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• 제8권2호
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• pp.85-88
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• 2003

The magnetic and transport properties far single crystals of Ru-doped mono-layered manganites $La_{0.5}Sr_{1.5}-Mn_{1-x}Ru_xO_4$ (0$\leq$$\chi$$\leq$0.1) have been studied using neutron diffraction and magnetization measurements. Temperature dependent magnetization data reveal that with an increase in the Ru concentration the parent charge ordered antiferromagnetic state is gradually destroyed and new ferromagnetic phase evolves. In the low Ru-doped system spin glass behavior is apparent in low temperature region, which is confirmed by ac and do magnetization measurements. The competing magnetic interaction between Mn/Mn and Mn/Ru couples is the most likely cause of the spin glass transition.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2002년도 동계연구발표회 논문개요집
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• pp.84-85
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• 2002

Recently doped perovskite manganites have renewed interest because they exhibit a variety of unique magnetic and electronic behaviors such as colossal magnetoresistance (CMR), percolative phase separation, spin/charge/orbital ordering, and so on. For this reason, fabrication of thin films with the best surface morphology and controlling their magneto transport properties is essential for making magneto-resistive devices. (omitted)

• 한국광학회:학술대회논문집
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• 한국광학회 2008년도 하계학술발표회 논문집
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• pp.425-426
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• 2008

The Panda-type polarization maintaining fibers were fabricated by VAD(vapor-phase axial deposition) method. We fabricate Panda style polarization maintaining fibers that have small form factor($80{\mu}m$), high H-parameter of about $1{\times}10^{-4}/m$ and low optical loss of about 3dB/km.

• 교육시설
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• 제12권6호
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• pp.5-17
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• 2005

The purpose of the study is to propose architectural design standards of the Multi-purpose Auditorium planning in educational facilities. The success of the design is measured by how well variable elements are applied to parts of Multi-purpose Auditorium and designed and equipped so that all groups-amateurs, professionals, youth, and adult alike-may use it effectively. The use of this facility will extend over a wide range, including concerts, plays, motion pictures, forums, and other forms of presentation. The wall, stage, roof, windows, and furnitures are important parts of Multi-purpose Auditorium and variable elements can applied to these parts. To successfully application of variable elements, it is necessary that these elements are considered in planning phase including time schedule planning. Various elements are permit a more informal and flexible arrangement and extensive learning activity.

• Journal of Pharmaceutical Investigation
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• 제28권1호
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• pp.51-57
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• 1998

Tetracycline lyogel ointment consisting of hydroxy ethyl cellulose(HEC) in glycerin and Eudragit RS 100 in triacetin were prepared and then release characteristic were investigated. The physical properties of lyogel ointment such as viscosity, particle size and microscopic structures were also evaluated. The microscopic structures showed that lyogel particles containing drug were dispersed in the triactin solution. The release rate of drug from lyogel ointment as a function of HEC was not changed. However the release rate was significantly decresed when the amount of Eudragit RS 100 and triacetin in lyogel ointment was increased. The viscosity and weight fraction in external phase of lyogel ointment influenced the release rate. The current studies suggest that the release rate of drug can be controlled by changing of lyogel ointment compositions.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.409-413
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• 2008

In this paper, we introduce a platform of advanced multiple antenna system based on orthogonal frequency-division multiplexing (OFDM). The advanced multiple antennas have beamforming gain using array antenna. In array antenna systems, received signal has phase delay caused distance of each antennas, therefore it should compensate with optimum weight vector which calculated by Lagrange algorithm. To implement the presented above procedures using Digital Signal Processor (DSP), we should fixed-point design. The performance of implemented platform is verified through MATLAB$^{(R)}$ simulations with various signal environments.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부A
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• pp.304-307
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• 1998

High speed railway is under construction from Seoul to Pusan. A traveling train is large single phase load that consumes 14MW power in feeding system of high speed railroad. In this paper, measurement scheme and method of power system harmonics which are generated from those loads in railroad supply system are described. This measurement scheme will be used as a first step to pave a way to power quality management due to harmonic distortion by the highspeed rail way.