• 한국산업융합학회 논문집
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• 제7권2호
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• pp.207-213
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• 2004

This paper describes the development of Behind-Tape-Reader (BTR) type DNC system using CYBER 180-830 as a central computer and IBM PC-AT cell control computer and NC lathe with FANUC 5T NC controller. In this system, the connection between central computer and cell control computer is done via RS-232C serial interface board, and that between cell control computer and FANUC 5T controller is done via parallel interface board. The software consists of two module, central computer communication module for NC program downloading and status uploading, NC machine running module for NC operating.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.2067-2070
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• 2002

In this paper, a VLSI architecture for transform and quantization module, which consists of 2D-DCT, quantization, AC/DC prediction block, scan conversion, inverse quantization and 2D-IDCT, is presented. The architecture of the module is designed to handle a macroblock data within 1064 cycles and suitable for MPEG-4 video codec handling CIF image formats. Only single 1-D DCT/IDCT cores are used for the design instead of 2-D DCT/IDCT, respectively. 1-bit serial distributed arithmetic architecture is adopted for 1-D DCT/IDCT to reduce the hardware area in this architecture. As the result, the maximum utilization of hardware can be achieved, and power consumption can be minimized. The proposed design is operated on 27MHz clock. The experimental results show that the accuracy of DCT and IDCT meet the IEEE specification.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1269-1276
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• 2014

The main objective of this paper is to design DC-DC MPPT circuit using chaotic pulse width modulation to track maximum power from solar PV module for space application. The direct control method of tracking is used to extract maximum power. The nominal duty cycle of the main switch of DC-DC SEPIC converter is adjusted so that the solar panel output impedance is equal to the input resistance of the SEPIC converter which results better spectral performance in the tracked voltages when compared to conventional PWM control. The conversion efficiency of the proposed MPPT system is increased when CPWM is used as a control scheme

• 융복합기술연구소 논문집
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• 제3권2호
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• pp.45-49
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• 2013

Instant custom embroidered souvenir manufacturing system was studied. Recently customers want to get individually specialized souvenir. We present a modular manufacturing system and implementation of image processing, conversion of punching data. The manufacturing system consist of main module, photographing module and U/I module. We can change the system easily through modularization. Image Processing was necessary for making punching data. We developed sketch typed image processing and image processing which used brightness. Brightness type is suitable for instant embroidered souvenir. This study showed that fusion of embroidery technology and image processing technology can make a new business successfully.

• Journal of Power Electronics
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• 제13권2호
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• pp.296-303
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• 2013

This paper proposes a high efficiency three-phase cascaded phase shifted H-bridge multi-level inverter without DC/DC converters for grid-tied multi string photovoltaic (PV) applications. The cascaded H-bridge topology is suitable for PV applications since each PV module can act as a separate DC source for each cascaded H-bridge module. The proposed phase shifted H-bridge multi-level topology offers advantages such as operation at a lower switching frequency and a lower current ripple when compared to conventional two level topologies. It is also shown that low ripple sinusoidal current waveforms are generated with a unity power factor. The control algorithm permits the independent control of each DC link voltage with a maximum power point for each string of PV modules. The use of the controller area network (CAN) communication protocol for H-bridge multi-level inverters, along with localized PWM generation and PV voltage regulation are implemented. It is also shown that the expansion and modularization capabilities of the H-bridge modules are improved since the individual inverter modules operate more independently. The proposed topology is implemented for a three phase 240kW multi-level PV power conditioning system (PCS) which has 40kW H-bridge modules. The experimental results show that the proposed topology has good performance.

• 전기학회논문지P
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• 제63권3호
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• pp.183-188
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• 2014

Power conversion systems used in large gas turbine power plant can be divided into two main part. Because of the initial start-up characteristic of the gas turbine combustor, the gas turbine must be accelerated by starting device(LCI : Load Commutated Inverter) up to 10%~20% of rated speed to ignite it. In addition, the ECS(Excitation Control system) is used to control the rotor field current and reactive power in grid-connected synchronous generator. These two large power conversion systems are located in the same space(container) because of coordination control. Recently, many manufactures develop high speed controller based on function block available in the LCI and ECS with the newest power semiconductor. We also developed high speed controller based on function block to be using these two system and it meets the international standard IEC61131 as using real-time OS(VxWorks) and ISaGRAF. In order to install easily these systems at power plant, main controller, special module and IO module are used with high speed communication line other than electric wire line. Before initial product is installed on the site, prototype is produced and tests are conducted for it. The performance results of Integrated controller and application program(SFC, ECS) were described in this paper. The test results will be considered as the important resources for the application in future.

• 전기학회논문지
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• 제58권1호
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• pp.100-106
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• 2009

A novel 8 V DC power source with an external series-parallel connection of 50 Dye-sensitized Solar Cells (DSCs) has been proposed. One DSC has the optimized length to width ratio of $5.2{\times}2.6\;cm$ and an active area $8\;cm^2$ ($4.62{\times}1.73\;cm$) which attained a conversion efficiency of 4.02%. From the electrochemical impedance spectroscopic analysis, it was found that the resistance elements related to the Pt electrode and electrolyte interface behave like that of diode and the series resistance corresponds to the sum of the other resistance elements. Surface morphology and sheet resistance of Pt counter electrode did not degrade the performance of the cell. This novel 8V-0.33A DC power source shows stable performance with an energy conversion efficiency of 4.24% under 1 sun illumination (AM 1.5, Pin of $100\;mW/cm^2$).

• Current Photovoltaic Research
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• 제10권4호
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• pp.107-110
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• 2022

Lightweight and flexible photovoltaic (PV) modules are attractive for building-integrated photovoltaic (BIPV) applications because of their easy construction and applicability. In this study, we fabricated lightweight and flexible c-Si PV modules using ethylene tetrafluoroethylene (ETFE) front cover and shingled design string cells. The ETFE front cover instead of glass made the PV modules lighter in weight, and the shingled design string cells increased the flexibility. Finally, we fabricated a PV module with a conversion power of 240.08 W at an area of 1.25 m² and weighed only 2 kg/m². Moreover, to check the PV module's flexibility, we conducted a bending test. The difference of conversion power between the modules before and after bending shown was only 1.7 W, which showed a power reduction rate of about 0.7%.

• 전기전자학회논문지
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• 제19권3호
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• pp.319-326
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• 2015

본 논문에서는 OPC 스택이 없는 제어기를 OPC DA 클라이언트와 통신하도록 하는 변환 소프트웨어 개발 기법을 제안한다. 제안된 기법은 OPC DA 표준 프로토콜에 기반을 둔 OPC 서버 구현, OPC 태그 및 포인트의 정보를 확인할 수 있는 GUI 개발, OPC 프로토콜에서 개방형 표준 프로토콜로 변환하는 변환모듈 개발 등의 3가지 과정으로 구성된다. OPC DA 표준 프로토콜에 기반을 둔 OPC 서버 구현 과정은 산업용 OPC DA 클라이언트와 OPC DA 프로토콜을 통하여 데이터를 주고받을 수 있도록 PC에 서버를 구현하는 단계이다. OPC 태그 및 포인트의 정보를 확인할 수 있는 GUI 개발 과정은 OPC 서버를 구동시키고 이를 윈도우 레지스트리에 등록하며 OPC 태그 및 포인트를 확인하고 직렬통신 데이터의 송수신 확인을 위한 GUI 개발 단계이다. OPC DA 프로토콜에서 개방형 표준 프로토콜로 변환하는 변환모듈 개발과정은 OPC DA 클라이언트로부터 수신된 OPC 태그의 데이터를 개방형 표준 프로토콜을 사용하는 산업용 제어기기와 직접적으로 통신을 할 수 있도록 프로토콜을 변환함으로써 데이터를 송수신 할 수 있는 변환모듈을 개발하는 단계이다. 개발된 소프트웨어의 효율성을 평가하기 위하여 본 논문에서 개발한 서버단의 소프트웨어와 OPC 클라이언트를 연결하고, 개방형 표준 프로토콜을 사용하는 5개의 샘플 제어기기와 연결하여 테스트 한 결과 전체 송수신 패킷 중에서 96.98%의 평균 통신 성공률을 나타내었다. 따라서 본 논문에서 제안한 OPC DA 변환 소프트웨어를 이용하여 Modbus 프로토콜을 지원하는 산업용 빌딩 제어 장치와 산업용 OPC DA 클라이언트 사이에 통신을 수행시킬 수 있음이 확인되었다.

• 한국전자파학회논문지
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• 제16권10호
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• pp.1050-1058
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• 2005

본 논문에서는 40 GHz 대역에서 동작하는 IEEE 802.16 고정 무선 통신 액세스를 위한 소형 저가격 및 광대역의 수신 모듈을 설계하고 구현하는 방법을 제안한다. 제안된 수신 모듈은 우수한 성능을 달성하기 위하여 캐비티 공정을 가지는 다층 LTCC 기술을 사용한다. 수신기는 저잡음 증폭기, 서브-하모닉 믹서, 내장된 이미지 제거필터와 IF 증폭기로 구성된다. 전송 손실과 모듈의 크기를 줄이기 위하여, 각 소자를 연결하기 위한 CB-CPW, 스트립 선로, 본드 와이어 및 천이(transition)들이 사용된다. LTCC는 유전율 7.1인 Dupont사의 DP-943을 사용하고 층수는 6층이며, 각 층의 높이가 100 um이다. 구현된 모듈의 크기는 $20{\times}7.5{\times}1.5\;mm^3$이며, 전체 잡음 지수는 4.8 dB 이하, 하향 변환 이득이 19.83 dB, 입력 P1 dB가 -22.8 dBm이고 이미지 제거값이 36.6 dBc 이상이다. 그리고 $560\~590\;MHz$ 대역의 디지털 TV 신호를 40 GHz 대역으로 상향 변환하여 전송시킨 후, 수신 모듈을 이용하여 시연하였다.