• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.72-77
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• 2009

In this paper, performance of a turbo-coded PLC system is analyzed and simulated in a power line communication channel. Since the power line communication system typically operates in a hostile environment, turbo code has been employed to enhance reliability of transmitted data. The performance is evaluated in terms of bit error probability. As turbo decoding algorithms, Max-Log-MAP algorithms are chosen and performances are compared. The results in this paper can be applied to OFDM-based high-speed power line communication systems

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.176-181
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• 2000

Stress intensity factors for a rigid line inclusion tying along a bimaterial interface are calculated by the boundary element method with the multiregion and double-Point techniques. The formula between the stress intensity factors and the inclusion surface stresses are derived. The numerical values of the stress intensity factors for the bimaterial interface rigid line inclusion in the infinite body are proved to be in good agreement within 3% when compared with the previous exact solutions. In the finite bimaterial systems, the stress intensity factors for the center and edge rigid line inclusions at interface are computed with the variation of the rigid line inclusion length and the shear modulus ratio under the biaxial and uniaxial loading conditions.

• Journal of Electrical Engineering and information Science
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• v.3 no.3
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• pp.300-305
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• 1998

This paper describes new sense amplifier with fast sensing delay time of 0.54ns and 32kb CMOS embedded SRAM with 4.67 ns access time for a 3-V power supply. It was achieved using the sense amplifier with multiple point sensing scheme and highs peed bit-line scheme. The sense amplifier saves 25% of the power dissipation compared with the conventional one while maintaining a very short sensing delay. The SRAM uses 0.5m double-polysilicon and triple-metal CMOS process technology. A die size is 1.78${\times}$mm2.13mm.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.899-904
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• 2007

Improvement projects has been progressed for railway electrification and double track line in the conventional line as well as high speed line for the high speed and large transportation capability of railway. Especially, many variable operation plans are possible such as interaction between high speed line and conventional line and operation of tilting train due to the electrification of the conventional line. Railway electrification is more energy efficient and environmentally-friendly, but it has some problems such as an enormous initial construction and maintenance costs and electrical accidents. Therefore, the more intensive research will be progressed about railway electrification effectiveness for the continuous electrification project. So, we analyzed railway electrification effectiveness about the energy side using annual operation data of electric car and diesel car. The energy side was divided into energy costs and national energy consumption for analyzing electrification effectiveness about entire line and specific line. We verified advantage of energy costs and national energy consumption in this paper and this result will contribute to the progress of the continuous electrification project and the more efficient operation ways in electrification line

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1660-1663
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• 2003

This paper present the characteristics of radiation pattern of microstrip slot antenna on the ground plane fed by microstrip line. It is proposed for resonance frequency at 10 GHz. We will analysis two shape of slot antenna; double L-shape slot antenna and U-shape slot antenna. In this case, we will compare far-field radiation pattern of two shape slot antenna. Far-field radiation pattern of double L-shape slot antenna is bi-directional nevertheless U-shape slot antenna is uni-directional. The microstrip slot antenna is propose to analyze far-field radiation pattern for use in the wireless communication systems

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.647-650
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• 2005

In this paper, a low voltage SRAM using double boosting scheme is described. A low supply voltage deteriorates the static noise margin (SNM) and the cell read-out current. For read/write operation, a selected word line and cell VDD bias are boosted in a different level using double boosting scheme. This increases not only the static noise margin but also the cell readout current at a low supply voltage. A low voltage SRAM with 32K ${\times}$ 8bit implemented in a 0.18um CMOS technology shows an access time of 26.1ns at 0.8V supply voltage.

• Transactions of Materials Processing
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• v.16 no.2 s.92
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• pp.132-137
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• 2007

A double roll rotary forming equipment is presented in this paper. The equipment is developed for joining the socket with the ball of a concave piston assembly with its geometrical tolerance requirements satisfied. The equipment is composed of a lathe, a double roll system and a roll pressing unit driven by the hydraulic system. The workpiece rotates by spindle chuck of the lathe while the double roll system approaches perpendicularly to the central line of the workpiece. The equipment is successfully applied to precision joining of the ball and the socket fur the concave piston assembly of a high pressure hydraulic pump.

• Proceedings of the KSR Conference
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• 2001.10a
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• pp.62-73
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• 2001

The scope of this study is focused on the survey of new logistics transportation systems in railroad and case studies of new systems such as piggyback system, bi-modal system swapbody, and double stack train(DST). Piggyback system, bi-modal system, swapbody, and double stack train are reviewed in term of technological validity and economic validity in Korea. Piggyback - trailer does pass loaded weight limits but does not pass train limits and can not utilize the existing freight cars. Piggyback - cargo trunk does pass all the criteria and could be developed by a domestic technology. But this study suggests to expand the length of train cars to 18.300mm for accommodation of two cargo trucks. Bi-modal system and swapbody do also pass. Double stack train could only pass the loaded weights and does not meet the train limit and the possibility of using existing freight cars. Domestic technology could not development DST, due to civil engineering construction limits and low standard height of electric line, which could not afford to operate DST.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.59-63
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• 2003

Modal properties of guided waves along circular dispersive double negative (DNG) index metamaterial rod waveguides are numerically investigated. Identical forms of dispersive dielectric and magnetic material constants are used for simplicity. For degenerated azimuthally symmetric mode, a multimode region, a single mode region, a band gap region and a forbidden region are found which cannot be observed in the case of the conventional dielectric rod waveguide. As the normalized frequency goes down, discrete guided modes are continuously generated, which is a reverse property of conventional dielectric rod waveguide. Also, there are high-frequency cutoffs, which have been generally examined in dispersive circular geometries such as a plasma column or a plasma Goubau line. In the single mode region, both the low- and high-frequency cutoffs are existed where the propagation constants are continued between the guided oscillating and surface modes.

• Proceedings of the KIEE Conference
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• 1997.07c
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• pp.1038-1040
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• 1997

This paper describes dynamic characteristics test of distance relay and current differential relay using Real Time Digital Simulator on double circuit transmission line. First, The double circuit T/L modeling on RTDS was proposed and the results from the proposed model were compared with those of PSS/E. This comparison shows the possibility of dynamic test using the RTDS. The relay included about 20 test items which are apt to include maloperation of protective relays in critical situations.