• Title/Summary/Keyword: HARRIS

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Distal Tibial Physeal Fracture in a Dog

  • Park, Won-Kyu;Kim, Young-Ki;Lee, Scott;Seo, Eu-Gene;Hwang, Jae-Min;Park, Ki-Tae;Wang, Ji-Hwan;Lee, Hee-Chun;Lee, Hyo-Jong;Yeon, Seong-Chan
    • Proceedings of the Korean Society of Veterinary Clinics Conference
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    • 2009.10a
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    • pp.230-230
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    • 2009
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Vision based Object Recognition for Autonomous Robot Navigation (로봇의 자율 항해를 위한 비전기반의 객체 인식)

  • Kim, Kwon;Lee, Chang-Woo;Xu, Sudan;Cui, Yao-Huan
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2008.06a
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    • pp.205-209
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    • 2008
  • 본 논문은 입력되는 영상에서 특정 객체를 찾기 위하여 특징 검출 및 매칭 결과를 분석하여 기술한다. 영상의 특징을 추출하는 방법 중 코너를 특징으로 하는 방법인 해리스 코너 검출(Harris corner detection)을 이용하여 코너를 추출하였으며, 추출한 특징을 이용하여 다양한 크기의 템플릿을 만들어 입력된 영상과 상관계수를 구해 최대값을 가지는 위치를 찾아 입력된 영상과 객체를 매칭 시킨 결과를 분석하였다. 본 논문의 연구 결과들은 객체의 탐지 등과 같은 영상 분석 기반 기술에 활용될 수 있으리라 기대된다.

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Improvment of Accuracy of Projective Transformation Matrix for Image Mosaicing (영상 모자이킹을 위한 사영 변환 행렬의 정밀도 개선)

  • 노현영;이상욱
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2002.11a
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    • pp.226-230
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    • 2002
  • This paper proposes a method of improvement of accuracy of projective transformation matrix for Image Mosaicing. Using shift theorem, we extracted global translation components between images and using translation components, we found matching points between images so we solve general matching point problem we extracted highly trusted matching point using RANSAC algorithm. we normalized matching point coordinates and improved accuracy of projective transformation matrix.

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Nonlinear PID Controller with Neural Network based Compensator (신경회로망 보상기를 갖는 비선형 PID 제어기)

  • Lee, Chang-Gu
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.49 no.5
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    • pp.225-234
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    • 2000
  • In this paper, we present an nonlinear PID controller with network based compensator which consists of a conventional PID controller that controls the linear components and neuro-compensator that controls the output errors and nonlinear components. This controller is based on the Harris's concept where he explained that the adaptive controller consists of the PID control term and the disturbance compensating term. The resulting controller's architecture is also found to be very similar to that of Wang's controller. This controller adds a self-tuning ability to the existing PID controller without replacing it by compensating the output errors through the neuro-compensator. Various simulations and comparative studies have proven that the proposed nonlinear PID controller produces superior results to other existing PID controllers. When applied to an actual magnetic levitation system which is known to be very nonlinear, it has also produced an excellent results.

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The Design Self Compensated PID Controller and The Application of Magnetic Levitation System (신경회로망을 이용한 자기 보상 PID 제어기 설계와 자기부양시스템 적용 실험)

  • Kim, Hee-Sun;Lee, Chang-Goo;Kim, Sung-Joong
    • Proceedings of the KIEE Conference
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    • 1998.11b
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    • pp.499-501
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    • 1998
  • In this paper, we present a self-compensating PID controller which consists of a conventional PID controller that controls the linear components and a neural controller that controls the higher order and nonlinear components. This controller is based on the Harris's concept where he explained that the adaptive controller consists of the PID control term and the disturbance compensating term. The resulting controller's architecture is also found to be very similar to that of Wang's controller. This controller adds a self-tuning ability to the existing PID controller without replacing it by compensating the control errors through the neuro-controller. When applied to an actual magnetic levitation system which is known to be very nonlinear, it has also produced an excellent results.

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Obstacle Position Detection on an Inclined Plane Using Randomized Hough Transform and Corner Detection (랜덤하프변환과 코너추출을 이용한 경사면의 장애물 위치 탐색)

  • Hwang, Sun-Min;Lee, Min-Cheol
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.5
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    • pp.419-428
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    • 2011
  • This paper suggests a judgement method for an inclined plane before entrance of it and the detection of obstacle position. Main idea is started from the assumption that obstacle is always on the bottom plane, and corner appears at this position. The process to detect the obstacle consists of three steps. First the 3D data using stereo matching is acquired to detect an obstacle. Second a bottom plane is extracted by using limit condition. Last the obstacle position is found by using Harris corner detection. Obstacle position detection on an inclined plane was verified by outdoor and indoor experiment. In error analysis, it is confirmed that an average error of obstacle detection in outdoor was larger than the error in indoor but the error are within about 0.030 m. This method will be applied to unmanned vehicles to navigate under various environment.

Vision-based AGV Parking System (비젼 기반의 무인이송차량 정차 시스템)

  • Park, Young-Su;Park, Jee-Hoon;Lee, Je-Won;Kim, Sang-Woo
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.5
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    • pp.473-479
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    • 2009
  • This paper proposes an efficient method to locate the automated guided vehicle (AGV) into a specific parking position using artificial visual landmark and vision-based algorithm. The landmark has comer features and a HSI color arrangement for robustness against illuminant variation. The landmark is attached to left of a parking spot under a crane. For parking, an AGV detects the landmark with CCD camera fixed to the AGV using Harris comer detector and matching descriptors of the comer features. After detecting the landmark, the AGV tracks the landmark using pyramidal Lucas-Kanade feature tracker and a refinement process. Then, the AGV decreases its speed and aligns its longitudinal position with the center of the landmark. The experiments showed the AGV parked accurately at the parking spot with small standard deviation of error under bright illumination and dark illumination.

Helical gear multi-contact tooth mesh load analysis with flexible bearings and shafts

  • Li, Chengwu;He, Yulin;Ning, Xianxiong
    • Structural Engineering and Mechanics
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    • v.55 no.4
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    • pp.839-856
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    • 2015
  • A multi-contact tooth meshing model for helical gear pairs considering bearing and shaft deformations is proposed. First, to easily incorporate into the system model, the complicated Harris' bearing force-displacement relationship is simplified applying a linear least square curve fit. Then, effects of shaft and bearing flexibilities on the helical gear meshing behavior are implemented through transformation matrices which contain the helical gear orientation and spatial displacement under loads. Finally, true contact lines between conjugated teeth are approximated applying a modified meshing equation that includes the influence of tooth flank displacement on the tooth contact induced by shaft and bearing displacements. Based on the model, the bearing's force-displacement relation is examined, and the effects of shaft deformation and external load on the multi-contact tooth mesh load distribution are also analyzed. The advantage of this work is, unlike previous works to search true contact lines through time-consuming iterative strategy, to determine true contact lines between conjugated teeth directly with presentation of deformations of bearings and shafts.

Selecting Varieties of Forage Rape Suitable for Spring Sowing at Southern Part of Korea (청예 사초용 유채의 춘파성 품종 반응)

  • 권병선;신정식;현규환;신동영;김학진;임준택
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2003.04a
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    • pp.67-70
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    • 2003
  • 사초용 유채는 영양가가 높은 사료작물이며, 한랭한 조건에서도 생육이 계속되어 좁은 사료작물 포장을 효율적으로 이용할 수 있다는 관점에서 그 잠재력이 매우 크다 (Harper 및 Compton, 1980 : Jung등, 1984 : Kay, 1975 : 김등, 1986 : 이등, 1984) 그리고 식물육종 학의 발달과 더불어 사초용 유채도 많은 품종이 개발 육성되고 있다 (Toxopeus 및 Boonman, 1983). 또한 사초용 유채는 다른 유채속 식물이나 방목용 초종에 비하여 조단백질과 조회분함량 및 소화률이 높고 조섬유 함량이 낮으나, 품종과 생육환경 및 수확시기에 따라 이들 함량에 차이가 있다(Berendank, 1982, 1982, 1983, 1983 : Groppel등, 1982 ; Gupta 등, 1974 ; Harris, 1964 : Jung 등, 1984, 1986)고 보고하였다.(중략)

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The Gringorten estimator revisited

  • Cook, Nicholas John;Harris, Raymond Ian
    • Wind and Structures
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    • v.16 no.4
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    • pp.355-372
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    • 2013
  • The Gringorten estimator has been extensively used in extreme value analysis of wind speed records to obtain unbiased estimates of design wind speeds. This paper reviews the derivation of the Gringorten estimator for the mean plotting position of extremes drawn from parents of the exponential type and demonstrates how it eliminates most of the bias caused by the classical Weibull estimator. It is shown that the coefficients in the Gringorten estimator are the asymptotic values for infinite sample sizes, whereas the estimator is most often used for small sample sizes. The principles used by Gringorten are used to derive a new Consistent Linear Unbiased Estimator (CLUE) for the mean plotting positions for the Fisher Tippett Type 1, Exponential and Weibull distributions and for the associated standard deviations. Analytical and Bootstrap methods are used to calibrate the bias error in each of the estimators and to show that the CLUE are accurate to better than 1%.