• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.14 no.1
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• pp.17-26
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• 2005

• Proceedings of the Korea Crystallographic Association Conference
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• 2001.11a
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• pp.15-15
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• 2001

• Progress in Medical Physics
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• v.15 no.1
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• pp.30-38
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• 2004

Purpose: To develop a whole body frame for the purpose of reducing patient motion and minimizing setup error for extra-cranial stereotactic radiotherapy, and to evaluate the repositioning setup error of a patient in the frame. Materials and Methods: The developed whole body frame is composed of a base plate, immobilizer, vacuum cushion, ruler and belts. The dimension of the base plate is 130 cm in length, 50 cm in width and 1 cm in thickness. The material used in the base plate of the frame was bakelite and the immobilizer was made of acetal. In addition, Radiopaque angio-catheter wires were engraved on the base plate for a coordinate system to determine the target localization. The measurement for radiation transmission and target localization is peformed in order to test the utilization of the frame. Also, a Matlab program analyzed the patients setup error by using the patient's setup images obtained from a CCTV camera and digital record recorder (DVR). Results: A frame that is useful for CT simulation and radiation treatment was fabricated. The frame structure was designed to minimize collisions from the changes in the rotation angle of the gantry and to maximize the transmission rate of the Incident radiation at the lateral or posterior oblique direction. The lightening belts may be used for the further reduction of the patient motion, and the belts can be adjusted so that they are not in the way of beam direction. The radiation transmission rates of this frame were measured as 95% and 96% at 10 and 21 MV, respectively. The position of a test target on the skin of a volunteer is accurately determined by CT simulation using the coordinate system in the frame. The estimated setup errors by Matlab program are shown 3.69$\pm$1.60, 2.14$\pm$0.78 mm at the lateral and central chest, and 7.11 $\pm$2.10, 6.54$\pm$2.22 mm at lateral and central abdomen, respectively. The setup error due to the lateral motion of breast is shown as 6.33$\pm$ 1.55 mm. Conclusion: The development and test of a whole body frame has proven very useful and practical in the radiosurgery for extra-cranial cancers. It may be used in determining target localization, and it can be used as a patient immobilization tool. More experimental data should be obtained in order to improve and confirm the results of the patient setup error.

• The Journal of the Acoustical Society of Korea
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• v.21 no.5
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• pp.446-454
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• 2002

This paper presents the Doppler Scanning technique which enables us to detect the relative positions of moving distributed sources using Doppler frequency shift estimate when the moving source consists of distributed sources with different signature frequencies. Doppler frequency shifts of characteristic frequencies of machinery noise sources such as ship's generator and propeller, with tine along CPA (Closest Point of Approach of moving source) are unique, and can be functioned with respect to each source position. Therefore, this technique can be applied to estimate the relative geometrical positions between machinery noise sources. The Extended Kalman Filter (EKF) which has a high frequency resolution with high time resolution, is adopted for improving accuracy of Doppler frequency shift estimate geometric resolution of machinery positions since machinery noise sources show in general low frequency band characteristics with limited spacial distance. The performance of the technique is examined by the numerical simulations and is verified by the experiment using loudspeaker sources on the roof of the car.

• Korean Journal of Optics and Photonics
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• v.15 no.1
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• pp.74-78
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• 2004

We propose a servo control method using a dome-type glass in shift-multiplexed holographic data storage. We frist store live 2-D data by shift-multiplexing in a holographic disk with 5％ variation in their. diffraction efficiencies. During read-out of the stored data, the servo control using the dome glass correctly compensates mechanical errors of the disk; the error of $\pm$0.2$^{\circ}$and run-out error of $\pm$50 ${\mu}{\textrm}{m}$. Use of the dome-type glass in servo control makes a pickup module more compact in size and easier to control than the previous method using parallel glass plate ［Sungphil Kim, et al., Hankook Kwanghak Hoeji, Vol. 14, No. 1, pp.58-64, 2003］.

• Journal of Bio-Environment Control
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• v.8 no.4
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• pp.223-231
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• 1999

The one of basic functional conditions of suspended overhead sprayer, which is openly made use of irrigating on bedding plants in greenhouse, is to be kept the growing uniformity of bedding plants by making uniformly the spraying irrigation depending on the distribution of sprayed water. This study was performed to find out the optimum position of sector formed injection nozzle which is placed from the top of plant 0 the tip of the nozzle to keep spraying uniformity. The test of spraying distribution using a overhead sprayer, which was installed in a row of sector formed injection nozzles, was performed The measuring factor to represent spraying distribution was the water weight filled in each cup when the overhead sprayer was moving across the upside of the cups which were placed directly under the nozzles on keeping the distance from nozzle tip. The test results were as following , The standard mr of weights of each cup filled with spraying water was lower values at Position far from more than 60cm under nozzle tip. The driving speed variation of sprayer was not effected on spraying uniformity but the spraying water weight was inversely proportioned to the speed. To make best spraying uniformity, it was represented that the tip of the nozzle is positioned to keep the distance which the top of plants is placed at the second cross point of each injection sector of nozzles.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.3
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• pp.369-374
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• 2010

Linear motors are easily affected by load disturbances, force ripples, friction, and parameter variations because there are no mechanical transmissions that can reduce the effects of model uncertainties and external disturbance. In this study, a nonlinear adaptive controller to achieve high-speed/high-accuracy position control of a two-axis linear motor is designed. The operation of this controller is based on a cross-coupling algorithm. Nonlinear effects such as friction and force ripples are estimated and compensated for. An enhanced cross-coupling algorithm is proposed for effectively improving the biaxial contour accuracy while achieving closed-loop stability. The proposed controller is evaluated by performing computer simulations.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.34-40
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• 2000

• Proceedings of the Korean Information Science Society Conference
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• 2001.10b
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• pp.328-330
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• 2001

컴퓨터 비전을 이용한 자동차 번호판 인식은 자동차에 특별한 장치가 필요없어 비용면에서 유리하다. 자동차 번호판을 인식하기 위해서는 번호판의 영역을 추출한 후 번호판에서 문자와 숫자 영역을 분리하고 그 세그먼트를 신경 회로망 혹은 다른 방법을 통하여 인식한다. 본 논문은 자동차 번호판 위치 검출 방법과 세그멘테이션 방법에 대하여 제안한다. 자동차 번호판 위치 검출을 위하여 모폴로지 기법과 ART2 클러스터링 방법을 이용하였고 검출한 번호판 영역에서 세그멘테이션은 모폴로지 연산을 이용한 이진화와 레이블링을 이용한다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.06d
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• pp.163-166
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• 2007

통신모듈이 포함된 많은 컴퓨팅 장치들이 다가오는 미래에는 유비쿼터스 네트워크 디바이스가 될 것이다. 센서 네트워크도 그런 유비쿼터스 네트워크의 어플리케이션이다. 대부분의 경우 센서 네트워크는 플러딩기반의 on-demand 에드혹 라우팅 프로토콜을 사용하나, 플러딩에 따른 중복된 패킷 전송을 최소화 하기 위해, 위치 정보를 사용하고 장애물까지 고려한다. 본 논문은 건물 내 유비쿼터스 센서 네트워크에서 위치 기반과 장애물을 고려한 플러딩을 제안한다.