• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.252-255
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• 1990

Analyzing and simulating of today's complex electrical networks require the use of computer-aided engineering tools. In recent years, the rapid advances in micro-computer hardware technology have increased the availability of power application software on the personal computer, once the domain of mainframes and minicomputers, enabling efficient and cost-effective power system analysis. An interactive simulation and analysis software for a power system is developed and presented in this paper. The software is written in PASCAL and is designed for PC use. This paper presents an integrated software package to run PC-DOS for the analysis of electric power networks. The software is menu driven and controlled by prompts. These programs are intended to help users understand the process of power system analysis and design.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.521-523
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• 2007

기존의 PCS는 저 출력에서 효율과 전력 품질이 낮은 단점을 가지고 있다. 이로 인하여 발전 사업자용 태양광 발전 인버터로 사용 시 전력 생산량이 떨어지게 된다. 이를 개선하기 위해서, 한 대의 단일 PCS 내에서 두 대의 인버터 스택을 적용, 개별/병렬 운전하여 효율과 전력품질을 향상시키고자 하며, 향후 500kW급 인버터 개발에 기초 기술개발을 위하여 본 논문에서는 50kW급 계통 연계형 병렬 운전 PCS를 개발하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.546-548
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• 2011

컴퓨터 실습실에서 사용되고 있는 씬 클라이언트 PC는 개인별로 할당된 것이 아니라 다수의 사용자들이 공유하기 때문에 씬 클라이언트 PC를 관리하기 위한 별도의 관리시스템(Management System)이 필요하다. 본 논문에서는 컴퓨터 실습실 환경에서 가상머신에 원격으로 접속된 씬 클라이언트 PC의 전원관리를 효과적으로 할 수 있는 방법을 제안한다. 사용자가 이용하는 씬 클라이언트 PC에 대해 일정시간 동안 키보드/마우스의 입력이 없으면 해당 씬 클라이언트 PC로 메시지를 전송하여 사용 여부를 확인하고 해당 사용자로부터 아무런 응답이 없을 경우 씬 클라이언트 PC를 Shutdown 한다. 이러한 관리 방법은 사용되지 않는 씬 클라이언트 PC에 대해 불필요하게 낭비되는 전력을 줄일 수 있어 효율적으로 컴퓨터 실습실을 운영할 수 있을 것으로 예상된다.

• Journal of KIISE:Computing Practices and Letters
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• v.7 no.6
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• pp.593-601
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• 2001

This paper presents an efficient system for power system education using 3-D computer graphics animation in the PC environment. Several power system phenomena are simulated using Real-Time Digital Simulator. Results are transmitted through on-line communication line to PC for graphic animation, and simulated in the 3-D graphics animation. It can immediately reflect user control input and re-simulated this result. The proposed method was tested on both the sub-synchronous resonance phenomena and multi-bus system. It is expected that the proposed method would be helpful for the operator training as well as power system education.

• Bulletin of the Korean Chemical Society
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• v.35 no.3
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• pp.705-708
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• 2014

We demonstrate the blue InGaN/GaN multiple quantum wells light-emitting diodes (LEDs) with an embedded air-gap photonic crystal (PC) which was fabricated by the lateral epitaxial overgrowth of GaN layer on the tungsten (W) nano-masks. The periodic air-gap PC was formed by the chemical reaction of hydrogen with GaN on the W nano-mask. The optical output power of LEDs with an air-gap PC was increased by 26% compared to LEDs without an air-gap PC. The enhanced optical output power was attributed to the improvement in internal quantum efficiency and light extraction efficiency by the air-gap PC embedded in GaN layer.

• Macromolecular Research
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• v.9 no.3
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• pp.129-142
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• 2001

To efficiently demonstrate the molecular motion, physical properties, and mechanical properties of polycarbonates, we studied the differences between bisphenol-A polycarbonate(BPA-PC) and tetramethyl bisphenol-A-polycarbonate(TMBPA-PC) using molecular modeling techniques. To investigate the conformations of BPA-PC and TMBPA-PC and the effect of the conformation on mechanical properties, we performed conformational energy calculation, molecular dynamics calculation, and stress-strain curves based on molecular mechanics method. From the result obtained from conformational energy calculations of each segment, the molecular motions of the carbonate and the phenylene group in BPA-PC were seen to be more vigorous and have lower restriction to mobility than those in TMBPA-PC, respectively. In addition, from the results of radial distribution function, velocity autocorrelation function, and power spectrum, BPA-PC appeared to have higher diffusion constant than TMBPA-PC and is easier to have various conformations because of the less severe restrictions in molecular motion. The result of stress-strain calculation for TMBPA-PC seemed to be in accordance with the experimental value of strain-to-failure ∼4%. From these results of conformational energy calculations of segments, molecular dynamics, and mechanical properties, it can be concluded that TMBPA-PC has higher modulus and brittleness than BPA-PC because the former has no efficient relaxation mode against the external deformations.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.505-506
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• 2007

Organic photovoltaic effects were studied in a device structure of ITO/CuPc/Al and ITO/CuPc/$C_{60}$/BCP/Al. A thickness of CuPc layer was varied from 10 nm to 50 nm, we have obtained that the optimum CuPc layer thickness is around 40 nm from the analysis of the current density-voltage characteristics in CuPc single layer photovoltaic cell. From the thickness-dependent photovoltaic effects in CuPc/$C_{60}$ heterojunction devices, higher power conversion efficiency was obtained in ITO/20nm CuPc/40nm $C_{60}$/Al, which has a thickness ratio (CuPc/$C_{60}$) of 1:2 rather than 1:1 or 1:3. Light intensity on the device was measured by calibrated Si-photodiode and radiometer/photometer of International Light Inc(IL 14004).

• Journal of the Korean Ceramic Society
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• v.43 no.1 s.284
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• pp.38-41
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• 2006

Surface of PC (Polycarbonate) and PES (Polyethersulphone) treated by plasma modification with rf power from 50 W to 200 W substrates in Ar (3 sccm), $O_2$ (12 sccm) atmosphere. From the results of modified substrates in XPS (X-ray Photoelectron Spectroscopy), the ratio of oxide containing bond increased with rf power. As the rf power was 200 W, the contact angle was the lowest value of 14.09 degree. And the datum from AFM (Atomic Force Microscopy), rms roughness value of PES and PC substrates increased with rf power. We could deposit $Ta_2O_5$ with good adhesion on plasma treated PES and PC substrates using by in-situ rf magnetron sputter.

• Journal of Korea Game Society
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• v.7 no.1
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• pp.53-58
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• 2007

In this paper, a game control system was constructed, in which a game was controlled by a remote joystick connected with a power line by the power line communication (PLC) method. The structure of the system was that the connection line between the remote joystick and a PC, and the PC and an audio play device was the home power line. And, the communication data rate between them was 2400 bps. The Polling communication technique was used for the PC to read the joystick's control commands, and to send some acoustic informations to the receiver PLC device. A game was programmed, in which an aircraft was moved according to the joystick's left, right, up, and, down direction, and was shooting its missile after the joystick's shooting button was pushed. The communication delay of about 100 msec between them didn't cause any big problem in playing the game.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.293-294
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• 2010