• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 D
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• pp.778-780
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• 2000

The 74181 is arithmetic logic units(ALU)/function generator. This circuit performs 16 binary arithmetic operations on two 4-bit words. And a full carry look-ahead scheme is made available in this device. The 74181 can also be utilized as a comparator. This circuit has been also designed to provide 16 possible functions of two Boolean variables without the use of external circuitry. This paper analyzes the function of the logic and the implementation adopted in the design of 74181. The understanding of the logic characteristics of this chip enables us to improve future applications.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1196-1201
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• 2014

This paper presents an exploration on the effect of wind turbine contribution to the frequency control of individual systems that can be used for efficient power production in India. The research includes the study of Permanent Magnet Synchronous Generator (PMSG), in wind farms. The WTs are tested for inertia and for droop responses with intelligent fuzzy logic controllers (FLC) that choose Double Input Single Output (DISO) strategy that automatically sets gain constants, as well as combined responses for the WTs. Quantitative analyses are presented for the WTs for benefits and drawbacks including appropriate selection parameters. The analysis includes inertia, droop and combined inertia, droop schemes. The reconnaissance also incorporates inertia with FLC, droop with FLC, inertia and droop with FLC schemes for detailed study of WTs, so as to forecast and achieve proper frequency control. Moreover, the analysis provides the best suited method for frequency control in PMSG.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제5권1호
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• pp.83-87
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• 2005

This paper deals with the design and evaluation of the robust controller for a synchronous generator excitation system to improve the steady state and transient stability. The nonlinear characteristics of the system is treated as model uncertainties, and then the robust control techniques are introduced into the power system stability design to take into account these uncertainties at the controller design stage. The performance of the designed controller is examined by extensive non-linear time domain simulation. It is shown that the performance of the robust controller is superior to that of the conventional PI controller. This paper also proposes an improved digital exciter control system for a synchronized generator using a digitally designed controller with database. Results show that the proposed control system manifests excellent control performance compared to existing control systems. It has also been confirmed that it is easy for the proposed control system to implement digital control.

• 한국정밀공학회지
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• 제19권12호
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• pp.33-37
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• 2002

A short shot is a molded part that is incomplete because insufficient material was injected into the mold. Remedial actions to control the process conditions can be taken by the injection molding experts based on their knowledge and experience. However, it is very difficult for the non-experts to avoid short shot by finding the proper process conditions such as mold temperature, melt temperature and filling time. In this paper, an intelligent generator of the optimal process conditions based upon fuzzy logic algorithm is proposed so that trial and error can be minimized and the non-experts as well as the experts can also find the optimal process conditions.

• 대한전자공학회논문지SD
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• 제39권7호
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• pp.81-88
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• 2002

본 논문에서는 패턴 집단 생성 방식을 사용한 새로운 내장형 자체 테스트를 위한 테스트 패턴 생성기를 제안하였다. 제안된 기술은 클럭당 테스트 환경에서 작은 하드웨어 크기를 가지면서 미리 계산된 결정 테스트 집합을 가진다. 테스트를 제어하기 위한 회로는 간단하여 자동적으로 합성된다. 새로운 패턴 생성기를 기존의 방법들과 비교한 결과를 ISCAS 벤치마크 회로를 가지고 검증하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.402-405
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• 2001

A short shot is a molded part that is incomplete because insufficient material was injected into the mold. Remedial actions to control the process conditions can be taken by the injection molding experts based on their knowledge and experience. However, it is very difficult for the non-experts to avoid short shot by finding the proper process conditions such as mold temperature, melt temperature and filling time. In this paper, an intelligent generator of the optimal process conditions based upon fuzzy logic algorithm is proposed so that trial and error can be minimized and the non-experts as well as the experts can also find the optimal process conditions.

• 마이크로전자및패키징학회지
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• 제8권4호
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• pp.53-57
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• 2001

사출성형공정에서 미성형은 가장 빈번하게 발생하는 성형불량중의 하나이다. 이러한 미성형을 해결하기 위해 가상 경제적인 효율적인 방법은 공정조건을 개선하는 일이다. 그러나 대부분의 경우 사출 전문가의 오랜 기간 축적된 경험과 지식에 의존하기 때문에 여러 번의 시행착오을 겪어야 한다. 따라서 본 논문에서는 퍼지 알고리즘을 기반으로 하여 시스템에 적합한 공정조건을 찾는데 있어 시행착오를 줄이고, 또한 비전문가도 쉽게 적용학 수 있는 지능형 공정조건 생성 시스템을 제안하였다.

• 한국통신학회논문지
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• 제22권3호
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• pp.506-514
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• 1997

In this paper, we implement digital circuit of despreading delay lock loop for GPS receiver. The designed system consists of Epoch signal generator, two 13bit correlators which correlates the received C/A code and the locally generated C/A code in the receiver, the C/A code generator which generates C/A code of selected satellite, and the direct digital clock synthesizer which generates the clock of the C/A code generator to control the phase and clock rate, the clock controller, and the clock divider. The designed circuit has the function of the acquisition and tracking by the autocorrelation characteristics of Gold code. The controller generates each other control signals according to the correlation value. The designed circuit is simulated to verify the logic functional performance. By using the simulator STR-2770 that generates the virtual GPS signal, the deigned FPGA chip is verified the circuit performance.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.463-467
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• 1992

This paper describes the automatic generation of sequence control programs for DCS(Distributed Control System), PLC(Programable Logic Controller) and so on. Since there is no same manufacturing process, it is difficult to standardize sequence programs. We propose the automatic sequence control program generator which is CAD software using knowledge engineering technique.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권10호
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• pp.587-594
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• 2002

A low frequency square wave electronic ballast for the high intensity discharge(HID) lamps using fuzzy logic controller is developed. This electronic ballast consists a buck converter, a low frequency square wave full bridge inverter, a high voltage pulse generator for the HID lamp ignition, an over current protection circuit and an 8-bit microcontroller. The ballast system is operated on the constant current mode during the HID lamp start-up process and the system is operated on the constant power mode during steady state. Experimental results show that the fuzzy logic control operation is carried out successfully by the 8-bit microcontroller PIC16F877 In this electronic ballast system, in spite of the limited control bandwidth caused by low operating speed of the microcontroller, the good performance in the constant lamp current characteristic is obtained. Acoustic resonance of the HID lamps can be effectively avoided because the instantaneous In lamp power is fully constant due to the low frequency square wave drive.