• 전기학회논문지
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• 제60권2호
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• pp.451-454
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• 2011

In this paper, a wideband clock generator using novel Automatic frequency calibration(AFC) scheme is proposed. Wideband clock generator using AFC has the advantage of small VCO gain and wide frequency band. The conventional AFC compares whether the feedback frequency is faster or slower then the reference frequency. However, the proposed AFC can detect frequency difference between reference frequency with feedback frequency. So it can be reduced an operation time than conventional methods AFC. Conventional AFC goes to the initial code if the frequency step changed. This AFC, on the other hand, can a prior state code so it can approach a fast operation. In simulation results, the proposed clock generator is designed for DisplayPort using the CMOS ring-VCO. The VCO tuning range is 350MHz, and a VCO frequency is 270MHz. The lock time of clock generator is less then 3us at input reference frequency, 67.5MHz. The phase noise is -109dBC/Hz at 1MHz offset from the center frequency. and power consumption is 10.1mW at 1.8V supply and layout area is $0.384mm^2$.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.151-156
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• 2002

The output voltage of Synchronous Generator is regulated constantly by field current control in excitation system. A synchronous generator is equipped with an automatic voltage regulator(AVR), which is responsible for keeping the constant output voltage under normal operating conditions about various levels. High frequency PWM converter (Current Mode Control Buck converter) type excitation system for synchronous generator is able to sustain output voltage level properly when the fault condition happened. This paper deals with the design and evaluation of the excitation system controller for a synchronous generator to improve the steady state and transient stability. The simulation and experimental results show that the proposed excitation system is improve the respons time by the AVR(automatic voltage regulator) of 50kW synchronous generator that is applied the current mode control excitation system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.101-104
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• 1996

In nuclear power plants, workers are reluctant of works in steam generator because of the high radiation environment and limited working space. It is strongly recommended that the examination and maintenance works be done by an automatic system for the protection of the operator from the radiation exposure. In this paper, it is proposed a new approach to the development of the automatic vision system to examine and repair the steam generator tubes at remote distance. Digital signal processors are used in implementing real time recognition and examination of steam generator holes in the proposed vision system. Performance of proposed digital vision system is illustrated by experiment for similar steam generator model.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1996년도 추계학술대회 논문
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• pp.107-112
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• 1996

In this paper it is proposed a new approach to the development of the automatic vision system to examine and repair the steam generator tubes at remote distance. In nuclear power plants workers are reluctant of works in steam generator because of the high radiation environment and limited working space. It is strongly recommended that the examination and maintenance works be done by an automatic system for the protection of the operator from the radiation exposure. Digital signal processors are used in implementing real time recognition and examination of steam generator tubes in the preposed vision system, Performance of proposed digital vision system is illustrated by experiment for similar steam generator model.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.469-473
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• 1996

In this paper, it is proposed a new approach to the development of the automatic vision system to e famine and repair the steam generator tubes at remote distance. In nuclear power plants, workers are reluctant of works in steam generator because of the high radiation environment and limited working space. It is strongly recommended that the examination and maintenance works be done by an automatic system for the protection of the operator from the radiation exposure. Digital signal processors are used it, implementing real time recognition and examination of steam generator tubes in the proposed vision system. Performance of proposed digital vision system is illustrated by experiment for similar steam generator model.

• 전자공학회논문지B
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• 제32B권5호
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• pp.661-670
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• 1995

This paper presents a fast massively parallel automatic test pattern generator for digital combinational logic circuits using neural networks. Automatic test pattern generation neural network(ATPGNN) evolves its state to a stable local minima by exchanging messages among neural network modules. In preprocessing phase, we calculate the essential assignments for the stuck-at faults in fault list by adopting dominator concept. It makes more neurons be fixed and the system speed up. Consequently. fast test pattern generation is achieved. Test patterns for stuck-open faults are generated through getting initialization patterns for the obtained stuck-at faults in the corresponding ATPGNN.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 춘계종합학술대회
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• pp.803-806
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• 2007

TRNG (True Random Number Generator)를 테스트 하는 방법은 PRNG (Pseudo Random Number Generator)나 산술연산기를 비롯한 결정적 (deterministic) 소자에 대한 테스트와는 많이 틀려서, 새로운 개념과 방법론이 제시되어야 한다. 하드웨어적으로 결정적인 소자들은 패턴을 사용한 테스트 (ATPG; automatic test pattern generation)에 의해 커버가 될 수 있지만, 순수 난수는 발생 결과의 아날로그적인 특성에 의하여 자동 패턴 생성 방식에 의해 소자를 테스트하기가 불가능하다. 본 논문에서는 하드웨어와 소프트웨어를 결합한 테스트 방식으로 테스트 패턴에 연속적인 패턴의 변화를 주면서 통계적으로 관찰하는 방식인 Diehard test라는 테스트 방식을 연구, 분석하고, 순수 난수의 테스트 시 고려해야 할 주안점을 제안한다.

• 전기학회논문지
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• 제61권10호
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• pp.1399-1411
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• 2012

The grid frequency is controlled cooperatively by the governor of the Turbine-Generator and the automatic generation controller(AGC) of the KPX(Korea Power Exchange). It is a basic requirement that the reliability of the governor is verified to enhance the power system stability but it is not easy to confirm the response characteristics of the governor because all generators are operated in the grid system that has the constant voltage and frequency. Therefore, it is necessary to study a new test method in order to examine the governor dynamic characteristic in the similar fault conditions. A study has shown that it is verified to simulate the turbine-generator power control system, the governor response characteristic under limited conditions and contribution of AGC with the gas turbine generator simulation model as well as demonstrate the dynamic response of the governor with the developed governor dynamic characteristic tester based on digital controller while the turbine-generator is connected to the grid system. This tester is constructed by the built-in functions of the turbine-generator main controller. In this treatise, the theoretical background, development method and the results of both simulations and demonstrations are described as another way to verify the turbine-generator governor dynamic characteristics.

• 소음진동
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• 제10권4호
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• pp.623-628
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• 2000

This paper presents the automatic plumbness measuring system form improving the accuracy and working time for plumbness measuring of semi-umbrella type hydraulic turbine generator. It is general practice that rotating shaft should run within acceptable vibration limit. In order to obtain more accurate measuring data for single stage shaft on the semi-umbrella type, plumbness approach must be established carefully and accurately. Generally, present plumbness procedure is required several calculation algorithm, laser sensor and data acquisition devices. As a result of application to actual new system it is confirmed that working time could be saved over 80% and accurate measurement data could be acquired.

• 한국항공우주학회지
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• 제30권1호
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• pp.139-146
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• 2002

다목적 실용위성 1호의 초기운영과 정상임무운영을 위한 임무 및 명령계획 작업은 MAPS(Mission Analysis & Planning Subsystem)의 임무 및 명령계획 S/W를 이용하였다. 시간이 지날수록 요구되는 임무양이 증가하면서 수동작업이 많아 요구되는 기존 S/W를 이용하여 임무운영을 수행할 경우 안정성이 크게 저하되었으며, 자동 처리과정이 부족하여 결과검증에 소모되는 시간도 증가하였다. 다목적 실용위성 관제국은 이를 개선하고자 보다 신속하고 안전하게 임무 및 명령계획 작업을 수행할 수 있으며, 중요 과정들을 자동화하여 임무운영의 안정성을 높일 수 있는 새로운 임무 및 명령계획 S/W를 개발하였다. 본 논문은 다목적 실용위성 1호의 임무계획 및 자동 명령계획표 생성기(KSCG, KOMPSAT-1 Scheduling & Automatic Command Plan Generator)의 개발내용과 실제 운영결과를 기술하였다. KSCG를 사용한 결과, 작업능률 향상과 임무운영 안정성을 획기적으로 높였다.