• 전자공학회논문지A
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• 제32A권8호
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• pp.56-63
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• 1995

A new method is presented for the synthesis of lossy tapered transmission line having presecribed frequency characteristic in the passband. The theory of lossy case extends lossless cases suggested by Klopfenstein and others, and a special optimization process based on the Fourier transfrom pair and generalized Taylor's procedure is proposed for exact designs of frequency-dependent and distance-dependent lossy tapered line. The process is achieved by control of zero points of lobe-like input reflection coefficient. The validity of the suggested method is confirmed by synthesizing a lossy microstrip transformer and analyzing the simulation results.

• 한국경영과학회지
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• 제22권1호
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• pp.25-49
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• 1997

Printed circuit board (PCB) assembly line configuration is characterized by very long set-up times and high work in process (WIP) inventory level. The scheduling method can significantly reduce the set-up times and WIP inventory level. Greedy sequence dependent scheduling (GSDS) method is proposed based on the current methods. The proposed method is compared with the current method in terms of three performance measures: line throughput, average WIP inventory level, and implementation complexity.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1802-1809
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• 2011

A distribution method of limited budget for rail line facility improvement is to use investment priorities of rail line segments based on their deterioration. In this paper we present an evaluation method of rail line segment deterioration which can be used to distribute limited budget. Rail line facilities include rail track, crossing, road bed, bridge, tunnel. These facilities deterioration and line shape can affect line segment deterioration. Deterioration evaluation method we present is a weighted sum of each component deterioration scores. The component weight can be obtained from experts using analytic hierarchy process.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.832-835
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• 1997

In this paper, we first analyze the structural limitation of the conventional PID controller in controlling unstable processes through mathematical proof. To overcome this structural limitation, we add an internal feedback loop to the PID controller. Secondly, we obtain conditions when unstable processes can be stabilized by a controller through an analytical analysis. Finally, we propose a simple on-line process identification and autotuning method for unstable processes. Many simulation results show that, in spite of its simplicity, the proposed on-line process identification method provides good accuracy in modeling the unstable process and acceptable robustness to measurement noises and disturbances. Also, the proposed autotuner shows good control performances for both servo and regulatory problems.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1412-1415
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• 1996

In this paper, a new identification method of the cascade control system is proposed which can overcome the weak points of Krishnaswamy and Rangaiah(1987)'s method. This new method consists of two steps. One is on-line process identification using the numerical integration to approximate the two process dynamics with a high order linear transfer function. The other is a model reduction technique to derive out low order transfer function(FOPTD or SOPTD) from the obtained high order linear transfer function to tune the controller using usual tuning rules. While the proposed method preserves the advantages of the Krishnaswamy and Rangaiah(1987)'s method, it has such a simplicity that it requires only measured input and output data and simple least-squares technique. Simulation results show that the proposed method can be a promising alternative in the identification of cascade control systems.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 하계종합학술대회 논문집(5)
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• pp.211-214
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• 2002

Under a continuous manufacturing process, two dimension inspection system causes problems as blurring effect and low resolution and requires position calibration between frames. One dimension inspection system is, therefore, being researched as a substitution. In this paper, we implement mechanism of switching memory and processing data for reasonable one dimension inspection system. Redundant weft image and noise was suggested to be reduced by new method using modified morphological process and masked erosion process. From resulting image, line data and possible error information were obtained and constructed as a structure. Finally, error detecting algorithm was performed with this data structure. Processing time of error detecting was 0.625ms per line in applied system and experiment showed 94.7% of error detecting ability. This method is 20% faster in speed and 2.7% higher in error detecting ability comparing with the present method.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.354-359
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• 1994

On-line process control equipment for CO $_{2}$ laser cutting is unavailable for industrial application. The major part of the industrial cutting machines are regulated off-line by highly educated engineers. The quality inspection of the sample is visual and referred to different quality scales. Due to lack of automation potential laser users hesitate to implement the cutting method. The first step toward an automation of the process is development of a process monitoring system and the research is concentrated on the area of on-line quality detection during CO $_{2}$ laser cutting. The method bases on the detection of the emitted light from the cut front by photo diode. the signal from photo diode has been undertaken from Fourier analysis and statistical analysis. As a result, it is possible to estimate striation pattern according to beam travel speed.

• 한국태양에너지학회 논문집
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• 제23권4호
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• pp.1-9
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• 2003

In this study, a manufacturing process for PV module has been developed using an automatic arraying equipment. It is expected that this process could improve the productivity and curtail the production cost in the photovoltaic module production line. From the results, it is proved that this process reduces Line-stop and enhances the productivity more than 15% a day which can be related directly to the production line cost.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 제2회 박판성형심포지엄 논문집 박판성형기술의 현재와 미래
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• pp.95-101
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• 1998

The steel door inner was manufactured via a new route, tailored blanking process, to remove hinge reinforcement parts, using thicker panels laser welded, instead. It is very important, first of all, in this process, to design optimum configuration of tailored blanks and determine the optimum process control for the stamping. Generally, it was found that the severe deformation reduction behavior during stamping in the thinner panel around weld line caused cracks and the other troubles in formability. It is our purpose of this investigation to introduce how the process control parameters, such as tailored blank configuration, size, location in the die, the position of weld line, BHF, bead configuration, work on the formability. In addition, causes of cracks and movement of weld line after forming were analyzed and compared with computer simulation work.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.737-740
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• 1996

This paper suggests a boltzman machine neural network model to determine model input sequences in line balancing process of mixed model assembly line. We first present a proper energy function, next determine the value of parameters using simulation process.