• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1032-1038
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• 2008

KTX train system is composed of TORNAD* network for transmitting information of train's internal equipments and OBCS which proceed information within train. OBCS of one trainset consisted of 28 equipments takes intelligent and dynamic composition according to equipment handling, train command and control flow. Each OBCS which is installed within trainset handle and supervise mutually action information about equipments, transmit it to driver to transmit information about train operation and preventive management. This mutual supervision and information transmission use KTX TORNAD* network system. TORNAD* network system is the one which is uniquely developped by GEC ALSTHOM, the KTX trainset manafacturing provider and this field is excluded from technical know-how transfer item. Through the research on analysis method of KTX TORNAD* system data structure which is operating on Seoul-Pusan Line, I hope that this thesis can contribute to train network system's standardization after applying it to improvement of train network system maintenance, enhancing quality of train service and applying it to future Korean rolling stock network system development.

• 한국응용과학기술학회지
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• 제18권3호
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• pp.191-196
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• 2001

Organic semiconductors based on vacuum-deposited films of fused-ring polycyclic aromatic hydrocarbon have great potential to be utilized as an active layer for electronic and optoelectronic devices. In this study, pentacene thin films and electrode materials were deposited by Organic Molecular Beam Deposition (OMBD) and vacuum evaporation respectively. For the gate dielectric layer, photoacryl (OPTMER PC403 from JSR Co.) was spin-coated and cured at $220^{\circ}C$. Electrical characteristics of the device were investigated, where the channel length and width was 50 ${\mu}m$ and 5 mm. It was found that field effect mobility was 0.039 $cm^{2}V^{-1}s^{-1}$, threshold voltage was -8 V, and on/off current ratio was $10^{6}$. Further details will be discussed.

• 대한조선학회논문집
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• 제30권2호
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• pp.86-97
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• 1993

수치방법은 포텐셜 유동의 가정하에서 Semi-Lagrangian 기법을 사용하여 2차원 쇄기의 비선형운동과 축대칭 물체의 강제 상하동요 운동에 대해서 개발되었다. 2차원에서 Cauchy 이론은 경계를 따라서 복소포텐셜과 그것의 미분치를 계산하기 위해 적용되었고, 3차원에서 Rankinering 쏘오스가 사용되고 대수방정식을 풀기위해서 그린 제2정리를 이용하였다. 해는 완전한 사유표면 조건을 수치적분함으로서 시간전진시킨다. 수치계산 예는 정속도로 입수하는 쇄기형 주상체와 정지 상태로 부터 강제상하동요하는 문제를 택하였다. 쇄기입수 문제는 Chapman [4], Kim[11]의 계산결과와 비교된다. 위에서 적용된 기법을 이용하여 구한 시간영역에서 힘을 Fourier 변환함으로서 부가질량계수, 감쇄계수, 2차조화력등이 얻어지고 Yamashita[5]의 실험치와 비교된다.

• ETRI Journal
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• 제19권4호
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• pp.402-413
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• 1997

A CMOS device which has an extended heavily-doped amorphous silicon source/drain layer on the field oxide and an amorphous silicon local interconnection (ASLI) layer in the self-aligned source/drain region has been studied. The ASLI layer has some important roles of the local interconnections from the extended source/drain to the bulk source/drain and the path of the dopant diffusion sources to the bulk. The junction depth and the area of the source/drain can be controlled easily by the ASLI layer thickness. The device in this paper not only has very small area of source/drain junctions, but has very shallow junction depths than those of the conventional CMOS device. An operating speed, however, is enhanced significantly compared with the conventional ones, because the junction capacitance of the source/drain is reduced remarkably due to the very small area of source/drain junctions. For a 71-stage unloaded CMOS ring oscillator, 128 ps/gate has been obtained at power supply voltage of 3.3V. Utilizing this proposed structure, a buried channel PMOS device for the deep submicron regime, known to be difficult to implement, can be fabricated easily.

• Bulletin of the Korean Chemical Society
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• 제27권4호
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• pp.519-523
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• 2006

Poly(dimethyl siloxane) (PDMS) has been employed as a microchip material for DNA separation in microfluidic condition. Different sieving molecules such as cellulose derivatives having glucose building block (methyl cellulose (MC), hydroxyethyl cellulose (HEC), and hydroxypropyl methyl cellulose (HPMC)) and polyethylene oxide (PEO) having linear (ring-opened ethylene oxide) unit were used and their performance was compared in terms of separation efficiency and resolution. In general, PEO showed better separation performance than cellulose derivatives probably due to the nature of linear shape polymer conformation. It was possible to perform at least 15 consecutive running with 1.2% PEO at the electric field strength around 200 V/cm. Fast analysis of the standard $\Phi$X 174 RF DNA/Hae III (less than 130s) was obtained with the number of the theoretical plate around 250,000/m. Our PMDS microchip was applied to the measurement of CAG repeat number, which is related to male infertile disease.

• 전기학회논문지
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• 제64권8호
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• pp.1256-1261
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• 2015

Along with the increase of railway catenary system operation speed to 400 km/h, there have been growing demands for good quality current collection systems that satisfy quality standards as well as criteria for safe working. Retaining uniform elasticity tension of contact wires is essential in maintaining high quality contact between pantograph and OCL (Overhead Contact Line) of current collection systems in high speed railways. Therefore, the tension of contact wire must be kept within tight tolerance limits in both working conditions and adverse weather conditions of catenary system. In accordance with these conditions, this paper presents a real time monitoring system for the tensioning device of the newly installed catenary system on the special route of Honam high speed line for 400 km/h operation. For the verification of the true value of tension of contact wires, we have developed ring-type tensioning sensors which were installed on supporting points of mast which compose the catenary system. According to the field test performed on the Honam high speed line catenary system, variation of tension was measured accurately in real-time.

• Bulletin of the Korean Chemical Society
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• 제26권6호
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• pp.952-958
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• 2005

Angiotensin-converting enzyme (ACE) is known to be primarily responsible for hypertension. Threedimensional quantitative structure-activity relationship (3D-QSAR) models have been constructed using the comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) for a series of 28 ACE inhibitors. The availability of ACE crystal structure (1UZF) provided the plausible biological orientation of inhibitors to ACE active site (C-domain). Alignment for CoMFA obtained by docking ligands to 1UZF protein using FlexX program showed better statistical model as compared to superposition of corresponding atoms. The statistical parameters indicate reasonable models for both CoMFA ($q^2$ = 0.530, $r^2$ = 0.998) and CoMSIA ($q^2$ = 0.518, $r^2$ = 0.990). The 3D-QSAR analyses provide valuable information for the design of ACE inhibitors with potent activity towards C-domain of ACE. The group substitutions involving the phenyl ring and carbon chain at the propionyl and sulfonyl moieties of captopril are essential for better activity against ACE.

• Geomechanics and Engineering
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• 제21권6호
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• pp.551-564
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• 2020

High-stress and complex geological conditions impose great challenges to maintain excavation stability during deep underground mining. In this research, large anisotropic deformation and its management by support system at a deep underground mine in Western Australia were simulated through three-dimensional finite-difference model. The ubiquitous-joint model was used and calibrated in FLAC3D to reproduce the deformation and failure characteristics of the excavation based on the field monitoring results. After modeling verification, the roles of mining depth also the intercept angle between excavation axis and foliation orientation on the deformation and damage were studied. Based on the results, quantitative relationships between key factors and damage classifications were presented, which can be used as an engineering tool. Subsequently, the performance of support system installation sequences was simulated and compared at four different scenarios. The results show that, first surface support and then reinforcement installation can obtain a better controlling effect. Finally, the influence of bolt spacing and ring spacing were also discussed. The outcomes obtained in this research may play a meaningful reference for facing the challenges in thin-bedded or foliated ground conditions.

• 전자공학회논문지S
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• 제35S권5호
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• pp.42-47
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• 1998

Bridcage RF coil is one of the most widely used RF coils in MRI. In order to use birdcage RF coils in open MRI systems, an open tructured birdcage RF coil has been investigated. By opening the ring structure of an original birdcage RF coil and driving the coil at two opening ends, the original birdcage RF coil can be modified to an open structured coil. In order to improve magnetic field uniformity of the open birdcage RF coil, driving voltage phases at the two opening ends can be controlled to be in-phase or out-of-phase each other. Operating frequency of the open birdcage RF coil has been theoretically derived, and the theoretical derivation has been verified by experiments.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권9호
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• pp.476-483
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• 1999

In this paper, electromagnetic forces acting on the rotor surface of a BLDC motor for hard disk drive are calculated by the finite element field analysis. The frequency characteristics of torque ripple, local force and unbalanced magnetic force as a source of mechanical vibration area analyzed. Ring-type permanent magnets for the brushless DC motor are apt to have different magnetization levels at each pole because of the unbalanced air gap between the magnet surface and the magnetizer fixture during the multi-poles magnetizing process. This paper discusses the effect of the unsymmetric magnetization distribution in the permanent magnet on the brushless DC motor performances. As a result, the unbalanced magnetic force acting on the rotor surface and the torque ripple are examined for the motor with an unsymmetric magnetization distribution, and compared with those of an ideally symmetric motor.