• 대한전기학회논문지:시스템및제어부문D
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• 제49권10호
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• pp.582-590
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• 2000

A fast optimal path planning algorithm using the analog Cellular Nonlinear Circuits(CNC) is proposed. The analog circuits based optimal path planning is very useful since most of the optimal path planning problems require real time computation. There has already been a previous study to implement the dynamic programming with analog circuits. However, it could not be applied for the practically large size of problems since the algorithm employs the mechanism of reducing its input current/voltage by the amount of cost, which causes outputs of distant cells to become zero. In this study, a subgoal-based dynamic programming algorithm to compute the optimal path is proposed. In the algorithm, the optimal paths are computed regardless of the distance between the starting and the goal points. It finds subgoals starting from the starting point when the output of the starting cell is raised from its initial value. The subgoal is set as the next initial position to find the next subgoal until the final goal is reached. The global optimality of the proposed algorithm is discussed and two different kinds of simulations have been done for the proposed algorithm.

• 한국정보처리학회논문지
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• 제4권8호
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• pp.2120-2132
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• 1997

아날로그 집적회로 설계 자동화를 위한 레이아웃 자동화 도구를 제안하였다. 구현된 시스템은 완전 주문형 방식을 채택하고 아날로그 레이아웃의 제약 조건을 고려하였다. 기존의 아날로그 레이아웃 자동화 도구들이 가지고 있는 단점을 보완하기 위하여 변수화된 모듈 라이브러리를 개발, 복잡한 아날로그 모듈들의 레이아웃을 지원하여 확장성을 극대화하였다. 또한 배선 과정에는 기존의 디크스트라 알고리즘을 개선한 종적 다중 경로 알고리즘을 적용하였다. 구현된 아날로그 레이아웃 자동화 도구는 비교기, 연산증폭기 그리고 필터등의 시험회로를 대상으로 시험 수행하였다. 기존의 자동화 도구인 OPASYN과 비교하여 웰 합병과 인터디지트형의 모듈로 레이아웃이 수행된 결과를 얻을 수 있었다.

• 대한전자공학회논문지SD
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• 제42권2호
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• pp.15-22
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• 2005

System-on-Glass 아날로그 회로를 구현하기 위해 요구되는 저항 matching 및 poly-Si TFT 특성을 기존 아날로그 회로를 이용하여 조사하였다. 저항 값, poly-Si TFT의 문턱전압 및 이동도의 matching 조건을 디스플레이 시스템의 해상도에 따라 유도하였다. 또한, 소스 드라이버를 구현하기 위해 요구되는 poly-Si TFT의 유효 이동도를 다양한 패널 크기에 따라서 분석하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 하계종합학술대회논문집
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• pp.847-850
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• 1998

One of the most difficult problem of designing VLSI is a mixed-circuit design, that is to design circuit containing both analog parts and digital parts. Digital to analog converter and analog to digital converter is a typical case. Especially it can be a serious problem when mixed circuit are put into a large digital circuit like microcontroller. However nowadays this problem is settled by separating analog circuit parts outside the IC. This technique is based on converting a digital signal into a pulse sequence. Then an analog signal is obtained by averaging this pulse sequence at the external low-pass filter. An anlog to digital converter is designed using a stochastic logic instead of a traditional PWM (pulse-width modulation) signal and ins implemente dusing FPGa. Stochastic pulse sequence can be made as a simple circuits and moreover can be mathematically processed by simple circuits -AND gates. The spectral property of stochastic pulse sequence method is better than that of PWM method. So it make easy to design a external low-pass filter. This technique has important advantages, especially the reduction of the ADC cost.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(3)
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• pp.149-152
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• 2000

We propose simple analog MOS circuits producing the one-dimensional compact motion-sensing circuits. In the proposed circuit, the optical flow is computed by a number of local motion sensors which are based on biological motion detectors. Mimicking the structure of biological motion detectors made the circuit structure quite simple, compared with conventional velocity sensing circuits. Extensive simulation results by a simulation program of integrated circuit emphasis (SPICE) indicated that the proposed circuits could compute local velocities of a moving light spot and showed direction selectivity for the moving spot

• 전자공학회논문지A
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• 제33A권3호
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• pp.135-139
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• 1996

It is difficult to fabricate precise resistors for the analog integrated circuits using MOS technology. Until now polysilicon resistors were used at the analog integrated circuits, but some deviations of resistance and sensitive variation processes still cause their misactions. In order to improve these misactions, we suggest a CMOS resistor cell which provides precise resistance and excellant linearity. Also we designed the second order active low pass filter using the CMOS resistor cells and verified their superior performances compared to the actual resistors.

• 전기의세계
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• 제14권2호
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• pp.1-7
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• 1965

This paper describes the commutation current and ignition angle of current which occures in the combination of silicon rectifier with synchronous generator when the constants of rectifier circuits parameters are changed. This is precisely accomplished by setting-up the analog computer with voltage generating circuits and non-linear elements circuits. When the characteristics of rectification are properly selected in the simulation, this method is able to extend to the connection of SCR and electric machinery. We also expect that this method is helpful to the investigation of characteristics, and design of alternating exciters, self-excited synchronous generators instead of D-C machines.

• Journal of Electrical Engineering and Technology
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• 제13권6호
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• pp.2485-2492
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• 2018

The rapid development of large-scale integrated circuits has brought great challenges to the circuit testing and diagnosis, and due to the lack of exact fault models, inaccurate analog components tolerance, and some nonlinear factors, the analog circuit fault diagnosis is still regarded as an extremely difficult problem. To cope with the problem that it's difficult to extract fault features effectively from masses of original data of the nonlinear continuous analog circuit output signal, a novel approach of feature extraction and dimension reduction for analog circuit fault diagnosis based on wavelet packet decomposition, local linear embedding algorithm, and clone selection algorithm (WPD-LLE-CSA) is proposed. The proposed method can identify faulty components in complicated analog circuits with a high accuracy above 99%. Compared with the existing feature extraction methods, the proposed method can significantly reduce the quantity of features with less time spent under the premise of maintaining a high level of diagnosing rate, and also the ratio of dimensionality reduction was discussed. Several groups of experiments are conducted to demonstrate the efficiency of the proposed method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1166-1169
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• 1987

A new analog-la-digital structure. called cyclic-parallel analog-to-digital(A/D) converter, has been developed for video applications. It consists of a M-bit parallel A/D converter, a digital-to-analog(D/A) converter, a differencing amplifier with gain of $2^M$ and two sample-and-hold circuits. In this structure, the input signal is circulated around the circuits K times, thereby converted into a MK-bit digital word. The proposed converter retains speed advantages of conventional series-parallel converters, with half reduced circuit components.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.330-332
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• 2006

A short distance laser range detector was developed on digital circuit. The circuit changed the analog circuit to digital circuit as possible as. The currently available laser range circuit one uses analog circuit mainly. But this ranger design targeted mass production with digital reporting function. So digital circuits replaced the analog circuit except amplifier and remained minor circuits those are hard to replace with digital circuit. The simulation shows that it is possible to make a reasonable distance measuring circuit on a digital circuit for very low price compare to analog circuit one.