• 수산해양기술연구
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• 제22권1호
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• pp.34-40
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• 1986

This paper deals with a new bit conversion method. When 12 bit AID converter is adapted to 16 bit micro-computer, complicated data aquisition method is not necessary to acquire the AID converted data into memory of computer. However, when the 12 bit AID converter is adapted to the 8 bit micro-computer 12 bit data should be divided into 4 bit data and 8 bit data. Therefore the old data-dividing method made 4 bitl2byte of memory space wasted. On the contrary, using the new bit conversion method suggested in this paper the two of 12 bit data are converted into 3 byte of data without extending the AID conversion time.

• 한국정보통신학회논문지
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• 제8권7호
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• pp.1442-1447
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• 2004

본 논문에서는 HDD나 LAN 둥에 응용하기 위하여 아날로그 신호와 디지털 신호를 동시에 처리하는 VLSI의 내장용 회로로 사용하기에 적합한 CMOS 6-비트 폴딩-인터폴레이팅 AD 변환기를 설계하였다. 고속 데이터 통신에 사용하기 위하여 VLSI에 내장되는 아날로그 회로는 작은 칩의 크기와 적은 소비전력, 빠른 데이터 처리속도를 필요로 한다. 제안한 폴딩-인터폴레이팅 AD 변환기는 서로 다른 원리로 동작하는 2 개의 폴더를 캐스케이드로 결합하여 전압비교기와 인터폴레이션 저항의 개수를 현저히 줄일 수 있으므로 내장형 AD 변환기의 설계에 많은 장점을 제공한다 설계 공정은 0.25${\mu}m$ double-poly 2 metal n-well CMOS 공정을 사용하였다. 모의실험결과 2.5V 전원전압을 인가하고 500MHz의 샘플링 주파수에서 27mW의 전력을 소비하였으며 INL과 DNL은 각각 $\pm$0.lLSB, $\pm$0.15LSB이고 SNDR은 10MHz 입력신호에서 42dB로 측정되었다.

• 전기학회논문지
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• 제57권6호
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• pp.985-993
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• 2008

This paper proposes a new DFIG(Doubly-Fed Induction Generator) system using matrix converter, which is very effectively used for interconnecting the wind power system to the power grid. The operation of proposed system was verified by computer simulations with PSCAD/EMTDC software. The feasibility of hardware implementation was conformed by experimental works with a laboratory scaled-model of wind power system. The laboratory scaled-model was built using a motor-generator set with vector drive system, and a matrix converter with DSP(Digital Signal Processor). The operation of scaled-model was tested by modeling the specific variable-speed wind turbine using the real wind data in order to make the scaled-model simulate the real wind power system as close as possible. The simulation and experimental results confirm that matrix converter can be applied for the DFIG system.

• 한국산업정보학회논문지
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• 제22권2호
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• pp.71-78
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• 2017

본 논문에서는 휴대기기용 DC-DC 부스트 컨버터를 설계하였다. 제안하는 DC-DC 부스트 컨버터는 1MHz의 스위칭 주파수로 구동되며, 인덕터, 출력 커패시터, MOS 트랜지스터 등으로 이루어지는 파워단 부분과 보호회로단, 컨트롤블럭단으로 구성하였다. CMOS magnachip $0.18{\mu}m$ 공정을 이용하여 SPICE 모의실험을 통하여 동작을 확인하였고, 칩을 제작하여 모의실험결과와 비교 분석하였다. 설계된 컨버터는 3.3 V 입력 전압 조건에서 출력전압 4.8 V 가 나타났고, 출력전류 95 mA 로 기존의 25~50 mA보다 큰 출력을 얻었다.

• 한국해양공학회지
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• 제11권4호
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• pp.189-196
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• 1997

An oil tracking system that monitors the spilt oil trajectory by using GPS was developed. The system consists of a tracking buoy deployed on the oil spilt area and an onshore(or onboard) monitoring station. The tracking buoy is equipped with GPS, signal converter, handy radio and battery while the monitoring station includes a station radio, signal converter, antennas and PC. The hull shape of buoy is designed to effectively simulate the spilt oil movement at sea surface. Radio sets for HAM are used as a data transmitter and a data receiving station, and signal converter is also for amateur use. A field experiment was conducted and it was shown that the integrated system is relable and robust. The developed oil tracking system reveals reatively good performance at reasonable cost. In favorable environment the system may communicate in the distance more than 50km.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2015년도 추계학술대회
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• pp.90-92
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• 2015

본 연구는 산업용 모니터링 장비의 통신 프로토콜 해석에 대한 자료를 수집 분석하여 기존에 프로토콜 해석을 위해 소요되었던 시간을 효과적으로 단축하고자 하였다. 산업용 모니터링에 많이 이용되는 프로토콜인 Modbus와 NMEA0183의 데이터를 분석하여 사용자가 활용할 수 있는 데이터로 변환할 수 있도록 하였다. 프로토콜 컨버터의 메인보드는 AVR128을 이용하였고, RS232C, Ethernet 통신이 가능하도록 구성하였다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권4호
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• pp.739-749
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• 2015

A new conceptual dual-buoy Wave Energy Converter (WEC) for the enhancement of energy extraction efficiency is suggested. Based on actual wave data, the design process for the suggested WEC is conducted in such a way as to ensure that it is suitable in real sea. Actual wave data measured in Korea's East Sea (position: $36.404N^{\circ}$ and $129.274E^{\circ}$) from May 1, 2002 to March 29, 2005 were used as the input wave spectrum for the performance estimation of the dual-buoy WEC. The suggested WEC, a point absorber type, consists of two concentric floating circular cylinders (an inner and a hollow outer buoy). Multiple resonant frequencies in proposed WEC affect the Power Ttake-off (PTO) performance of the WEC. Based on the numerical results, several design strategies are proposed to further enhance the extraction efficiency, including intentional mismatching among the heave natural frequencies of dual buoys, the natural frequency of the internal fluid, and the peak frequency of the input wave spectrum.

• 대한기계학회논문집A
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• 제24권2호
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• pp.506-517
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• 2000

One dimensional performance model has been used for the design of torque converter. The model is based on the concept of constant mean flow path and constant flow angle. These constant-assumed para meters make the design procedure to be simple. In practice, some parameters are usually replaced with geometric raw data and, the constant experiential correction factors have been used to minimize the design error. These factors have no definite physical meaning and so they cannot be applied confidently to the other design condition. In this study, the detail dynamic model of torque converter is presented to establish the theoretical background of correction factors. To verify the validity of theoretical model, steady state performance test was carried out on the several input speed. The oil temperature effect on the performance is analysed and adjusted. The constant equivalent flow angles are determined at a part of performance region by comparing the theoretical model and the test data. The sensitivity of correction factors to the input speeds are studied and the change of torus flow is presented.

• 한국자동차공학회논문집
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• 제11권2호
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• pp.104-110
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• 2003

As exhaust emission standards are more stringent, higher conversion efficiency of automotive catalytic converter is required. In addition, catalytic converter is deteriorated during mileage accumulation of vehicle. Therefore the specification of catalytic converter should be decided in consideration of emission standards and deterioration. Because the decision of the specification of catalytic converter is required at the beginning of vehicle development procedure, it is important and necessary to fix the target values of green vehicle exhaust emissions. To do this, a linear regression analysis was done with in-use exhaust emissions data of 5 different kinds of vehicle that received US94 emission standards certification, and data handling methods including some statistical estimation were proposed. As a result, the fixed target values of NMHC, CO, NOx of green vehicle against US94 emission standards were 0.079, 0.83, 0.116, respectively. And expected in-use deterioration factor of NMHC, CO, NOx were 1.75, 2.02, 1.38, respectively. And also it was blown that even if failure rate is 30% after 80,000km driven, it might be sufficiently safe from emission failure confirmatory test of Korea. It is hopeful to make a database of in-use emissions to increase the confidence in correctness of the calculated target values.

• 한국CDE학회논문집
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• 제16권2호
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• pp.146-155
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• 2011

As the seriousness of environmental pollution being on a rise, a low carbon and environment-friendly design for energy efficiency has been issued. With respect to energy in the construction industry, an adoption of BIM which is possible for the various energy performance assessments in the early design phase has been actively working on. In the most cases of energy performance assessment, the data compatibility from the lack of standard software and format became a problem and the improvement for data compatibility system has been needed. This study is to develop the IFC based IDF converter as a middleware which connects between BIM software and energy analysis software. For the building energy performance assessment, Energy Plus and IFC are selected for the standard energy analysis software and its file format. Parameters are organized by steps and the integrated material library is built so it is trying to reduce the existing problem of energy software interface as much as possible. The development of IDF Converter will promote the spread of related fields with increasing the BIM standard and the utilization of energy performance assessment.