• 제목/요약/키워드: active set

검색결과 951건 처리시간 0.026초

레벨셋을 이용한 특정 영역의 영상 세그먼테이션 (Image Segmentation of Special Area Using the Level Set)

  • 주기세;조덕상
    • 한국정보통신학회논문지
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    • 제14권4호
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    • pp.967-975
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    • 2010
  • 영상 세그먼테이션은 배경으로부터 객체들을 구별하는 것으로서, 영상 분석과 해석을 하는데 있어서 첫 번째 단계에 해당한다. 그러나 활성 외곽선 모델은 위상이 2개밖에 없으므로 정확하게 원하는 객체들을 추출할 수가 없다. 본 논문에서 원하는 특정한 범위의 명암도를 갖는 객체들을 추출하기 위해서 초기 곡선을 객체들 근처에 구성함으로써 바라는 윤곽을 찾는 방법을 제안한다. 초기 곡선은 히스토그램 평활화, 가우시안 평활화, 임계치를 이용하여 구한다. 제안한 방법은 초기 곡선을 관심영역에 최대 근접시키므로 계산 속도를 줄이고 원하는 영역을 정확하게 추출할 수 있다. CT 영상과 MR 영상에 적용한 결과 제안한 방법이 활성 외곽선 모델보다 더 효과적임을 보였다.

Active Fault-Tolerant Control for a Class of Nonlinear Systems with Sensor Faults

  • Wang, Youqing;Zhou, Donghua;Qin, S.Joe;Wang, Hong
    • International Journal of Control, Automation, and Systems
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    • 제6권3호
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    • pp.339-350
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    • 2008
  • A general active fault-tolerant control framework is proposed for nonlinear systems with sensor faults. According to their identifiability, all sensor faults are divided into two classes: identifiable faults and non-identifiable faults. In the healthy case, the control objective is such that all outputs converge to their given set-points. A fault detection and isolation module is firstly built, which can produce an alarm when there is a fault in the system and also tell us which sensor has a fault. If the fault is identifiable, the control objective remains the same as in the healthy case; while if the fault is non-identifiable, the control objective degenerates to be such that only the healthy outputs converge to the set-points. A numerical example is given to illustrate the effectiveness and feasibility of the proposed method and encouraging results have been obtained.

ActiveX 기술을 이용한 분산 컴퓨팅 시스템 구현 (Implementation of Distributed Computing System using ActiveX Technology)

  • 송민규;변도영;제도홍;김광동;노덕규;오세진;이보안
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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    • pp.462-464
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    • 2004
  • ActiveX is the general name for a set of Microsoft Technologies that allows users to re-use code and link individual programs together to suit their computing needs. In addition ActiveX technology Provides a standard model for interapplication communication that different programming language. ActiveX is based on COM(Component Object Model), the COM standard allow developer to create code and application from a multitude of different languages and build a defined interface to that code, making it easily accessible by other application. By using ActiveX, user can access the functionality of other applications running remote computer distributed through the network and communicate over the network to build distributed applications. LabVIEW provides access to other Windows applications using ActiveX technologies. So in this paper we implement distributed application using ActiveX technology for remote control and monitoring.

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Refinement of Ground Truth Data for X-ray Coronary Artery Angiography (CAG) using Active Contour Model

  • Dongjin Han;Youngjoon Park
    • International journal of advanced smart convergence
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    • 제12권4호
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    • pp.134-141
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    • 2023
  • We present a novel method aimed at refining ground truth data through regularization and modification, particularly applicable when working with the original ground truth set. Enhancing the performance of deep neural networks is achieved by applying regularization techniques to the existing ground truth data. In many machine learning tasks requiring pixel-level segmentation sets, accurately delineating objects is vital. However, it proves challenging for thin and elongated objects such as blood vessels in X-ray coronary angiography, often resulting in inconsistent generation of ground truth data. This method involves an analysis of the quality of training set pairs - comprising images and ground truth data - to automatically regulate and modify the boundaries of ground truth segmentation. Employing the active contour model and a recursive ground truth generation approach results in stable and precisely defined boundary contours. Following the regularization and adjustment of the ground truth set, there is a substantial improvement in the performance of deep neural networks.

어깨의 능동 수축을 동반한 관절가동술이 부리돌기와 위팔뼈 머리 사이의 거리에 미치는 영향 (The Effect of Mobilization Combined with Shoulder Active Contraction of Depth between the Coracoid Process and Humeral Head)

  • 김선민;장상훈
    • 대한정형도수물리치료학회지
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    • 제29권2호
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    • pp.69-75
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    • 2023
  • Purpose: This study examined the distance between the coracoid process and the humeral head using an ultrasonography device when shoulder active contraction were applied according to the guided direction in the end range of shoulder mobilization. This study aims to provide essential data on treating shoulder disease patients. Methods: The subjects of this study were 20 adults with healthy shoulder joints. ultrasonography (US) equipment was used to examine shoulder joint mobilization under two conditions: (1) anteroposterior (AP) joint mobilization and (2) superoinferior (SI) joint mobilization. Shoulder active contraction was assessed in the end range. The distance between the coracoid process and the humeral head was measured. A linear probe was used for US; the frequency was set to 7.5MHz, and the US image display method was set to B-mode. The US measurement values were measured in (1) the starting position, (2) the end range position, and (3) the end range position of the shoulder active contraction, and the moving distance was drawn in a straight line through the US image. The distance was determined as the measurement value, and the average values were compared. Reults: The results were as follows: (1) the measured AP Joint mobilization increased by an average of .52cm from the end range of the joint mobilization with shoulder active contraction; (2) the measured SI Joint mobilization increased by an average of .49cm from the end range of the joint. Conclusion: When shoulder mobilization is applied, the distance between the coracoid process and the humeral head increases when muscle contraction occurs through shoulder active contraction in the end range, according to the therapist's guidance. Therefore, shoulder mobilization combined with shoulder active contraction is an effective treatment method for patients with shoulder injuries.

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밝기 정보와 곡선전개 기반의 활성 모델 (Intensity Information and Curve Evolution Based Active Contour Model)

  • 김성곤
    • 정보처리학회논문지B
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    • 제10B권5호
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    • pp.521-526
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    • 2003
  • 본 논문에서는 영역의 경계를 추출하기 위해 영상의 밝기 정보와 곡선전개 방식을 이용한 기하 활성 모델을 제안한다. 영역의 경계를 추출하는 문제를 추출한 영역의 평균 밝기 값과 전개중인 폐곡선 영역의 밝기 값의 차론 최소화시키는 것으로 설정한다. 최적의 해를 구하는 방법으로 레벨세트 이론을 적용한 곡선전개 방법을 이용한다. 이 방식은 일반적인 활성 모델에 비해 초기 곡선 설정에 제약이 없고 동시에 여러 영역의 경계 추출이 가능하다. 제안 모델은 에지 정보가 충분치 못한 영상의 경우에도 일반적인 에지 기반 방식에 비해 추출 결과가 양호하였다. 비등방성 확산 필터를 사용하여 영상을 전처리 함으로써 보다 나은 추출이 수행되었다. CT나 MRI 영상을 이용하여 모델의 성능을 확인하였다.

Active Contours를 사용한 얼굴 검출 (Face Detection Using Active Contours)

  • 정도준;장재식;박세현;김항준
    • 한국멀티미디어학회:학술대회논문집
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    • 한국멀티미디어학회 2002년도 춘계학술발표논문집(상)
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    • pp.195-199
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    • 2002
  • 본 논문에서는 주어진 입력 이미지에서 얼굴 영역을 검출하기 위한 액티브 컨투어 모델(active contour models)을 제안한다. 제안한 모델은 스킨 칼라 모델(skin color model)에 의해 표현되는 사람 얼굴의 칼라 정보를 이용한다. 본 논문에서는 첨점(cusps), 모서리 (corners), 그리고 자동 위상 변화(automatic topological changes)를 고려한 레벨 셋 메소드(level set method)를 사용하여 액티브 컨투어를 진화시킨다. 실험 결과는 제안한 방법이 얼굴 영역 검출에 효과가 있음을 보여준다.

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Diagnostic and Active Filtering of Harmonics Generated by Compact Fluorescent Lamps

  • Moulahoum, Samir;Houassine, Hamza;Kabache, Nadir
    • Journal of international Conference on Electrical Machines and Systems
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    • 제3권2호
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    • pp.162-168
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    • 2014
  • Use of nonlinear loads, such as power converters, fluorescent lamps and adjustable speed motor drives, is expected to grow rapidly. All of these loads inject harmonic currents. This paper presents the active filtering of the harmonic distortion generated by the compact fluorescent lamps (CFL). The Instantaneous active and reactive power theory (the p-q Theory) is used to design the control of parallel active filter. The control scheme has been verified using Matlab/Simulink with SimPower Systems through a set of simulation tests under different load conditions. Also, the tuning of the active power filter is performed to improve the quality of the electrical power supply.

Extension of Fast Level Set Method with Relationship Matrix, Modified Chan-Vese Criterion and Noise Reduction Filter

  • Vu, Dang-Tran;Kim, Jin-Young;Choi, Seung-Ho;Na, Seung-You
    • The Journal of the Acoustical Society of Korea
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    • 제28권3E호
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    • pp.118-135
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    • 2009
  • The level set based approach is one of active methods for contour extraction in image segmentation. Since Osher and Sethian introduced the level set framework in 1988, the method has made the great impact on image segmentation. However, there are some problems to be solved; such as multi-objects segmentation, noise filtering and much calculation amount. In this paper we address the drawbacks of the previous level set methods and propose an extension of the traditional fast level set to cope with the limitations. We introduce a relationship matrix, a new split-and-merge criterion, a modified Chan-Vese criterion and a novel filtering criterion into the traditional fast level set approach. With the segmentation experiments we evaluate the proposed method and show the promising results of the proposed method.

실시간 위치추적을 위한 2.45GHz 능동형 고주파 시스템에 관한 연구 (A Study of 2.45GHz Active RF System for Real Time Location)

  • 김진영;정용섭;강준희
    • 대한공간정보학회지
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    • 제16권3호
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    • pp.43-49
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    • 2008
  • 실시간 위치추적 (Real Time Location System ; RTLS) 시스템은 유비쿼터스 사회에서 인물, 자산, 물류제품을 실시간으로 추적하기 위해 매우 중요하다. 본 연구에서는 RTLS를 위해 능동형 RF 시스템을 개발하였고 개발된 시스템의 성능을 측정하였다. 본 시스템에서 개발한 RTLS 시스템은 3개의 능동형 리더(수신기)와 1개의 태그로 구성되었다. 개발된 능동형 소형 태그에는 동전형 배터리를 내장하였다. 태그의 소형화를 위해 내장형 PCB 안테나와 칩 안테나를 장착하여 태그의 성능을 측정하였다. 또한, RF 시스템의 제조 원가를 줄이기 위해 저가의 RF 트랜시버 CC2510 칩셋을 사용하였다. CC2510 칩셋은 능동형 태그와 능동형 리더 (수신기)사이의 거리를 측정하기 위한 수신신호 강도지시기가 (Received Signal Strength Indicator ; RSSI) 내장되어있다.

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