• 대한전기학회논문지
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• 제38권7호
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• pp.569-581
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• 1989

This paper deals with a tracking algorithm based on integral projection which tracks moving targets with varying brightness and size. An adaptive windowing technique is employed to reduce the sensitivity of the system to the complex background image and also to reduce the computational load. The threshold value is determined by considering both the size and the threshold value of the brightness intensity of the recognized target obtained in the previous processing step. Window position is estimated by using the information of the velocity and acceleration of the target. And integral projection is applied to find the position of the target in the window accurately. Experimental results show that moving targets with varying brightness and size can be tracked properly in noisy environments.

• 대한전자공학회논문지TE
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• 제39권1호
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• pp.65-70
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• 2002

한반도 지역 내에서 KOREASAT의 수신성능 향상을 목적으로 하는 추적 시스템을 구현하였다. 위치정보 센서 없이 스캔 모드를 이용하여 위성이 수신 가능한 지역으로 안테나를 이동시켰고, Step 추적 알고리즘을 이용하여 수신 신호의 최대 레벨 점으로 이동하는 시스템을 구현하였다. 구현된 시스템의 추적 성능을 위성을 직접 수신하는 실물 실험을 통하여 검증하였다. 또한, 본 시스템의 추적 속도와 기계적 구조에 적합한 최적의 Step 크기도 반복 실험을 통하여 결정하였다.

• 한국정밀공학회지
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• 제22권12호
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• pp.77-86
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• 2005

This paper is about the development of Automatic FPC(flexible printed circuit) punching instrument for the improvement of working condition and cost saving. FPC is used to detect the contact position of keyboard and button like a cellular phone. Depending on the quality of the printed ink and position of reference punching point to the FPC, the resistance and current are varied to the malfunctioning values. The size of reference punching point is 2mm and the above. Because the punching operation is done manually, The punching accuracy is varied with operator's condition. Recently, The punching accuracy has deteriorated severely to the 2mm punching reference hall so that assembly of the K/B has hardly done. To improve this manual punching operation to the FPC, automatic FPC punching system is introduced. Precise mechanical parts like a 5-step stepping motor and ball screw mechanism are designed and tested and low cost PC camera is used fur the sake of cost down instead of using high quality vision systems for the factory automation. Test algorithms and programs showed good results to the designed automatic punching system and led to the increasement of productivity and huge cost down to law material like FPC by avoiding bad quality.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 하계종합학술대회 논문집
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• pp.75-78
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• 1989

In this paper, A last time delay damper is presented for HB ( HyBrid ) step motor, which has large oscillation characteristics.The design objective is to develop a cost-effective and good-performance damper that would be applyed to HB step motor / driver system without the addition of transducer that would add a weight, size and cost to the system. The Back EMF signal which is recovered from current and voltage signal is used for the measuring the rotor position. It would be possible to get more accurate delay time for the motor driver system. It is proved that the maximum overshoot can be reduced to 13% at stopping through experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.229-231
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• 1994

In recent years, as the industry has been highly developed and precised, its driving and control system have been changed, what is more, revolutionized. The requirements of these change are more accuracy, more high efficiency, more miniaturized size and more servo functions. Step motor has been adopted for driving servo systems, because of easier controllability, open-loop control, high position accuracy at low speed. In this paper, we deal with developing step motor system, and describe the procedure that contains design, analysis. testing characteristics.

• 한국의학물리학회지:의학물리
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• 제11권1호
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• pp.49-57
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• 2000

방사선 치료에 따른 방사선량 최적화 문제를 풀기 위한 새로운 방법이 제시되었다. 기존의 2차원 치료계획과는 달리 3차원 문제에서는 모든 조건이 훨씬 복잡하고 관련된 변수도 많아지기 때문에 문제를 해결하기가 쉽지 않다. 본 연구에서는 3차원 선량최적화 문제를 접근하는데 있어서, 해가 존재할 수 있는 범위를 줄여주고, 중요한 파라미터들을 미리 구해주어서 치료계획에 관련된 변수를 줄이는 방법을 연구하였다. 먼저 선형가속기와 환자좌표계사이의 좌표변환을 이용하여 두부 내의 중요기관을 피하는 빔 위치를 찾았다 그리고 임의의 빔 위치에 대해 병소를 완전히 감싸는 빔 크기와 콜리메이터 회전각을 구하였다. 그 결과 가능한 빔 위치를 줄여줄 수 있었고, 빔 크기와 회전각에 대한 의존성을 없앨 수 있었다. 따라서 고려해야할 변수의 조합이 크게 줄어들게 되었고, 목적함수를 이용한 선량최적화에 있어서 최소한의 변수로만 계산이 가능하게 되었다. 위의 결과를 이용하여 임상에 널리 쓰이는 2차원 방사선치료계획의 선량최적화 문제를 해결하였다. 선량기울기, 중요기관의 선량, 선량분포 균일도를 조합한 목적함수를 최소화하는 최적해를 step search 방법을 이용하여 구하였다. 그리고 이 최적해를 이용한 선량분포로부터 새로운 방법에 의한 선량최적화의 가능성을 확인할 수 있었고, 후속 연구를 통하여 상용 방사선 치료계획 시스템에 적용함으로써 임상에 쓰일 수 있을 것으로 사료된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.309-311
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• 2000

An advanced angular position detector (APD) for the SMART CEDM (control element drive mechanism) was designed. The APD is required to be small size with high resolution for angular displacement of rotary step motor. Unfortunately the proximity sensors can not be adopted to SMART CEDM because the motor shaft is located in the pressure boundary cylinder filled with the primary coolant under high temperature and pressure. This paper describes the electromagnetic finite element analysis for the design of advanced angular position detector for the SMART CEDM. The electromagnetic properties obtained will be used as Input for the optimization analysis of the APD.

• Journal of Astronomy and Space Sciences
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• 제15권1호
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• pp.229-234
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• 1998

We study on a terrain contour matching algorithm using Radial Basis Functions(RBFs) for aided inertial navigation system for position fixing aircraft, cruise missiles or re-entry vehicles. The parameter optimization technique is used for updating the parameters describing the characteristics of an area with modified Gaussian least square differential correction algorithm and the step size limitation filter according to the amount of updates. We have applied the algorithm for matching a sampled area with a target area supposed that the area data are available from Radar Terrain Sensor(RTS) and Reference Altitude Sensor(RAS)

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.161-166
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• 2001

The static characteristics of four-nozzle flapper valves are investigated with both constant flow and constant supply pressure. The ranges, in which linearization of these characteristics would be valid, are discussed. Linearized dynamic model is also derived. Numerical simulations of nonlinear dynamic model are carried out by HyPneu to make an assessment of the effect of input step size in both cases of no-load and blocked-load operation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.45-48
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• 1987

In applications of step-motor, the requirements of small-size and strong-power gave birth to feed-back drive to the maximum efficiency and complete damping. In this paper, a new scheme that determines switching times from sensed values of position and speed is presented for simple bang-bang type drive circuit. The optimal values of each phase switching times are obtained using conjugate gradient method.