• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2000.02a
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• pp.136-138
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• 2000

1.5kA HTS current leads for a superconducting magnetic energy storage(SMES) magnet, which are connected to a conventional vapor cooled copper leads, were designed. The HTS lead composed of cylindrically arranged Bi-2223/Ag-1 at5Au tapes and a stainless steel tube. The minimum operating current of the lead is 1.71 kA at 77.3K, self magnetic field, and the heat input to the liquid helium from the clod end of the 36 cm lead is 0.5 W/lead.

• Progress in Superconductivity and Cryogenics
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• v.4 no.1
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• pp.8-12
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• 2002

Since the high performance analog-to-digital converter can be built with Rapid Single Flux Quantum (RSFQ) logic circuits the development of superconductive analog-to-digital converter has attracted a lot of interests as one of the most prospective area of the application of Josephson Junction technology. One of the main advantages in using Rapid Sng1e Flux Quantum logic in the analog-to-digital converter is the low voltage output from the Josephson junction switching, and hence the high resolution. To design an analog-digital converter, first we have used XIC tool to compose a circuit schematic, and then studied the operational principle of the circuit with WRSPICE tool. Through this process, we obtained the proper circuit diagram of an 1-bit analog-digital converter circuit. The optimized circuit was laid out as a mask drawing. Inductance values of the circuit layout were calculated with L-meter.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1114-1115
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• 2015

This paper describes the design of toroid-type HTS DC reactor magnet. Target operating current and inductance of the HTS DC reactor are 1,500 A and 400 mH, respectively. The HTS DC reactors were designed through electromagnetic analysis and 3D CAD program. And, we analyze the operating performance of the Double Pancake Coil module for the 1,500 A, 400 mH HTS DC reactor magnet under the liquid nitrogen condition.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.173-174
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• 2008

The four-point bending test is a widely used method to determine material parameters. The aim of the present study was to evaluate the flexural strength (or modulus of rupture) and the Weibull modulus of cordierite ceramic substrate by means of four-point bending tests. The strength data from experiments followed Weibull statistics. These data indicate that the fatigue effects are more severe when the substrate temperature in the peripheral region is near $200^{\circ}$. At temperatures well above $200^{\circ}C$ the available design strength can be as high as 65% as substrate's initial strength.

• Journal of Advanced Marine Engineering and Technology
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• v.11 no.1
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• pp.39-52
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• 1987

Recently, the design problem of heat insulation have been reappraised in the aspect of energy saving due to the rising trend of energy cost. For example, that design problem is increasingly requsted in the fields of accommodation air conditioning systems, hot water supply systems, cargo handling systems, district heating or cooling systems. The rational design of heat insulation of piping systems can not only improve the overall efficiency of energy transfer but also give energy saving. In this paper, the heat insulation problem of district heating systems is therefore modeled as the multi-stage decision processes, suitable for dynamic programming technique. And take the object function as the sum of heat insulation material cost involved construction cost and heat loss cost, and propose the design method to minimize the object function for overall piping systems by dynamic programing. Effectiveness of design method presented here is proved by a computer simulation.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.63-64
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• 2012

In case of concrete, it should be deformed by many factors, such as explosive spalling, thermal strain and creep at high temperature. Structural fire design has been proposed to predict fire damage as national standard. It is general safer to use values obtained from tests of unstressed residual test in stead of stressed test. But most of thermal properties on concrete were conducted with normal aggregate. In this study, it evaluated mechanical properties of concrete with aggregate type and loading condition. we use normal and light aggregate to have different thermal properties. Also, we test mechanical properties to use Ø100×200 mm cylinder specimen according to target temperature and 0%, 20%, 40% loading.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.589-592
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• 2003

One important issue in the design and the optimization for conductor of a superconducting cable is the control of the current distribution flowing at each layers. In this paper, we calculated the self inductance of each layer and the mutual inductance between two layers from the magnetic field energy and investigated the effects of design parameters on the self and mutual inductances for 4-layer conductors with transport current distribution at each layer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.192-197
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• 1994

High-Tc superconducting magnet properties were dependent upon design conditions such as its radius, length, critical current and notch size. In order to study, design and the simulation for small size magnet were implemented. We know that intensity of magnetic fields controled by critical current and factor ${\alpha}$( R$_2$/R$_1$) and uniformity controled by notch size. The optimal condition of intensity and uniformity magnetic field in this experiments are R$_1$=3[cm], R$_2$=12[cm], Z=10[cm], ${\alpha}$=4, notch=6[cm], critical current=12[A].

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.12
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• pp.640-645
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• 2006

A 22.9kV/50MVA class high temperature superconducting(HTS) power cable system was developed in Korea. For the optimization of electrical insulation design for a HTS cable, it is necessary to investigate the ac breakdown impulse breakdown and partial discharge inception stress of the liquid nitrogen/laminated polypropylene paper(LPP) composite insulation system. They were used to insulation design of the model cable for a 22.9kV class HTS power cable and the model cable was manufactured. The insulation test of the manufactured model cable was evaluated in various conditions and was satisfied standard technical specification in Korea. Base on these experimental data, the single and 3 phase HTS cable of a prototype were manufactured and verified.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.857-859
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• 1999

본 연구에서는 Poly-Si TFT-LCD 패널에 내장할 수 있는 새로운 방식의 디지털 데이터 구동회로를 설계하였는데, 제안된 데이터 구동회로의 특징 및 장점을 요약하면 다음과 같다. 첫째, 단순한 구조의 샘플드램프 D/A Conversion 회로로 구성되어 회로가 복잡하지 않고, 소요되는 TFT의 수가 적으며, 패널의 스캔방식(Inversion Method : Row/Column/Dot)을 쉽게 선택할 수 있다. 둘째, 기존의 디지털 데이터 구동회로와는 달리, D/A Conversion을 위해 필요한 기준 전압원의 수가적어 입력 핀 수를 적게 가져갈 수 있다. 셋째, Ramp 신호의 조정에 의해 감마 보정 등을 포함한 데이터의 에러에 대한 보정이 수월하다. 넷째, 라인 스친 방식으로 구동하므로 기존의 샘플 앤 홀드방식의 아날로그 구동회로에 비해 화소 데이터의 시간적 안정성을 충분히 확보할 수 있다.