• Title/Summary/Keyword: Power Shift

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Feeder Reconfiguration Using Binary Coding Particle Swarm Optimization

  • Wu, Wu-Chang;Tsai, Men-Shen
    • International Journal of Control, Automation, and Systems
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    • v.6 no.4
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    • pp.488-494
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    • 2008
  • This paper proposes an effective approach based on binary coding Particle Swarm Optimization (PSO) to identify the switching operation plan for feeder reconfiguration. The proposed method considers the advantages and disadvantages of existing particle swarm optimization method and redefined the operators of PSO algorithm to fit the application field of distribution systems. Shift operator is proposed to construct the binary coding particle swarm optimization for feeder reconfiguration. A typical distribution system of Taiwan Power Company is used in this paper to demonstrate the effectiveness of the proposed method. The test results show that the proposed method can apply to feeder reconfiguration problems more effectively and stably than existing method.

Lapping of Chemical Vapor Deposited Diamond Films Using copper Vapor laser (화학기상증착 다이아몬드 막의 레이저 평탄화)

  • 박영준;백영준
    • Journal of the Korean Ceramic Society
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    • v.36 no.4
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    • pp.417-424
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    • 1999
  • Laser lapping of diamond films is performed with focused beam of copper vapor laser. Both spherical and rod-shape laser beam are used. Diamond surface is scanned at various scan speeds(0,125, 0.5, 0.75 mm/sec) and baem shifts (5, 10, 20, 40, 100$\mu\textrm{m}$) At 0.125 mm/sec 10$\mu\textrm{m}$ scan condition the level difference of di-amond surface of about 700$\mu\textrm{m}$ over 20 mm is reduced to 200$\mu\textrm{m}$ In addition surface roughness is also im-proved from 3.53$\mu\textrm{m}$ to 2.47$\mu\textrm{m}$ at 5$\mu\textrm{m}$ beam shift. But at higher beam shift than 10$\mu\textrm{m}$ laser scan makes the surface rougher which is considered to be due to the non uniform spatial distribution of laser en-ergy. It is concluded that homogenized laser beam with high average power is needed for large area laser lapping of diamond films at appreciable rates.

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Study on Grid-Connected Photovoltaic System using Current-Source Inverter (전류형 인버터를 이용한 계통 연계형 태양광 발전 시스템에 관한 연구)

  • Lim, J.M.;Park, S.J.;Lee, S.H.;Moon, C.J.;Choi, J.H.
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.677-681
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    • 2005
  • This Paper presents a 6 pulse shift operation control mode of current-source-inverter to make improvement of efficiency and to reduce the frequency of inverter switching for photovoltaic generation system using PWM current-source-inverter. This system is connected solar cell energy directly without using a storage cell. The proposed circuit can maintain maximum voltage of photovoltaic generation of take advantage of six Buck-Boost converter and a full-bridge inverter determines the polarity of AC output. That is controlled by using digital signal processor TMS320F2812 for operation about a 6 pulse shift operation control of current-source-inverter, and it is verified through the experimental results.

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Shift in Warfare Paradigm and Military Transformation (전쟁패러다임의 전환과 군사변혁)

  • Jeong, Chun-Il
    • Journal of National Security and Military Science
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    • s.4
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    • pp.381-418
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    • 2006
  • In present, advanced countries in the world are seen concentring on Military Transformation to create new military capability as there is a shift in Warfare Paradigm. Rapid development of technology enables military system, operational concept and organization innovated. As a result, Revolution in Military Affairs(RMA) that dramatically increased warfighting capability is pursued. Especially, advanced information technology constructs system of systems with abilities of battle visualization, information sharing in battlefield, long-range strike capability that are interoperable and combined. Corresponding to this, engagement methods and organizations are being progressively developed. The purpose of this thesis is overview of newly developing Warfare Paradigm and analysis of tendency of Military Transformation that advanced countries are pursuing preparation to this. Above all, specific aspects and contents of the Warfare Paradigm which emerged by information age were summarized. Subsequently, Military Transformation which provides the basic concepts and principles to the advanced countries in the world for the creation of new military capability was discussed. In conclusion, the tendency of Military Transformation by U.S.A, Japan, China, and Russia surround the Korean peninsular as the major power in military was carefully observed.

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Characteristic Analysis of RGB-LED Backlight for Current and Temperature Variations (RGB형 LED Backlight의 전류 및 온도 변화에 따른 특성 분석)

  • Lim, S.H.;Lim, J.G.;Shin, H.B.;Chung, S.K.;Shin, M.J.;Sohn, S.G.
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.244-246
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    • 2007
  • The LCD backlight technique using light-emitting diode(LED) has been studied in the recent backlight market. The white light is need for LCD backlight and it is generally implemented by combining the RGB-LEDs to obtain the high brightness. However, RGB-LEDs have different color characteristics for the current and temperature variations, which results in the color shift problem. The color shift characteristics of RGB-LEDs for the current and temperature variations are investigated in this paper. This result can be used to control the color of backlight system using RGB-LEDs.

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Design of DubaiSAT-1 S-band Receiver RF block (DubaiSAT-1 위성용 S-band 수신기의 RF 블록 설계)

  • Park, In-Yong;Min, Seung-Hyun;Kim, Byung-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.2
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    • pp.178-182
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    • 2011
  • A FSK receiver RF block has been developed for Dubaisat-1 Low Earth Orbit satellite. The receiver has Doppler tracking function which compensate frequency shift on uplink channel for commanding the satellite. It consist of LNA, downconverter and IF module. The IF module has Doppler tracking circuitry which sweep and lock on to input signal. It satisfies the requirement of the Dubaisat-1 in mass, power consumption, tracking speed and BER performance.

Paradigm Shift of Global Market and Pattern of Technology Innovation for Automotive Steel Sheets (자동차용 강판시장의 글로벌 패러다임 변화 및 기술혁신 패턴)

  • Jung, Kyung-Hee
    • Journal of Korean Institute of Industrial Engineers
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    • v.25 no.4
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    • pp.476-489
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    • 1999
  • This paper is concerned with the deployment of core technologies for automotive steel sheets, based on the structural change of global market. The main tasks of automotive industry are to ensure the energy consumption, environmental regulations, and driving safety. With social and legal requirements, this study analyzes the market creation processes with technological innovations for hot rolled, cold rolled and galvanized steel sheets during the 20th century. It has been proven that the leading country in the steel industry was also that in the automotive. The purchaser-supplier relations of sheet materials are then patternized in the regional markets of the United States and Japan, who share nearly 50% of market in the world. According to the paradigm shift of globalization, the balance of power in Porter's 5 forces has been moved to the buyers', and both industries pursue Win-Win strategies such as the PNGV(Partnership for a New Generation of Vehicles ) and design-in system with the competition.

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A study on the computer diagnosis that apply Neural-Fuzzy algorithm accumulation detection of Partial Discharge signal (광섬유 내의 유도 브릴루앙 산란광을 이용한 초고압전력케이블 열화진단에 관한 연구)

  • Hwang, Kyoung-Jun;Yeoum, Keoung-Tae;Kim, Yong-Kab;Kim, Jin-Su
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.1558-1559
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    • 2007
  • This study is an application field by using optical fiber. The system to measure sBs from optical fiber is designed, So it can be used as a temperature sensor. by using frequency shift, resulting from temperature changes. the frequency shift is checked by changing temperature from $25^{\circ}C$ to $69^{\circ}C$ with chamber in the laboratory and using 40Km optical fiber. It's also measured by varying the length of optical fiber The program to do the real-time monitoring and analyze the measured data is created to find accurate frequency. It can be used as an optical fiber sensor, which is capable of measuring temperature and distance by using sBs.

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Design of 6.6kW On-Board Battery Charger for Electric Vehicle using Phase-Shift Full-Bridge Converter (PSFB 컨버터를 이용한 전기자동차용 6.6kW 탑재형 충전기 설계)

  • Ahn, Jung-Hoon;Kim, Yun-Sung;Koo, Keun-Wan;Lee, Byoung-Kuk
    • Proceedings of the KIPE Conference
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    • 2012.07a
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    • pp.166-167
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    • 2012
  • 본 논문은 전기자동차 (Electric Vehicles, EVs)용 리튬 이온 (Li-Ion) 배터리의 충전 및 충전 속도 향상을 위하여 6.6kW급 고전력 탑재형 충전기 (On-Board Charger, OBC)를 설계한다. 높은 부하 가변범위와 차량 실장 특성을 고려하여 가용 가능한 토폴로지들 중 최적의 토폴로지로 위상천이 풀-브릿지 컨버터 (Phase-Shift Full-Bridge, PSFB)를 제안하고 타당성을 밝힌다. 또한 토폴로지를 구동하는 스위칭 주파수와 주요 수동소자의 변화에 따른 부피와 효율 등의 Trade-Off 관계를 이론적으로 전개하여 최적화한다.

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Analysis and Modeling of Slip Mode Frequency Shift Method for Anti-islanding (슬립모드 주파수변이 방식의 단독운전 검출법의 분석과 모델링)

  • Yu, Byung-Gyu;Jung, Young-Seok;So, Jung-Hun;Yu, Gwon-Jong
    • Proceedings of the KIEE Conference
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    • 2005.07b
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    • pp.1699-1701
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    • 2005
  • Islanding phenomenon is undesirable because it lead to a safety hazard to utility service personnel and may cause damage to power generation and rower supply facilities as a result of unsynchronized reclosure. In order to prevent this phenomenon, various anti-islanding methods have been studied. Even though the slip mode frequency shift(SMS) method has been regarded as a highly effective anti-islanding method, the analytical design method of that was not cleared. This paper proposes a modeling of the SMS method using non-detection tone(NDZ) and evaluation of the method according to the test conditions of IEEE Std. 929-2000. The SMS method is derived analytically through modeling and verified visually by simulation and experiment.

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