• 제목/요약/키워드: Edge estimation

검색결과 360건 처리시간 0.029초

Analysis of Tubular Structures in Medical Imaging

  • Kim, Jin-Woo
    • Journal of information and communication convergence engineering
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    • 제7권4호
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    • pp.545-550
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    • 2009
  • A method fully utilizing multiscale line filter responses is presented to estimate the point spread function(PSF) of a CT scanner and diameters of small tubular structures based on the PSF. The estimation problem is formulated as a least square fitting of a sequence of multiscale responses obtained at each medical axis point to the precomputed multiscale response curve for the ideal line model. The method was validated through phantom experiments and demonstrated through phantom experiments and demonstrated to accurately measure small-diameter structures which are significantly overestimated by conventional methods based on the full width half maximum(FWHM) and zero-crossing edge detection.

Development of Inspect Algorithm for Pallets Using Vision System

  • Lee, Man-Hyung;Hong, Suh-Il
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.101.6-101
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    • 2001
  • This paper deals with inspect algorithm using visual system. One of the major problems that arise during polymer production is the estimation of the noise of the product(bad pallets). An erroneous output can cause a lot of losses (production and financial losses). Therefore new methods for real-time inspection of the noise are demanded. For this reason, we have presented a development of vision system algorithm for the defect inspection of PE pallets. First of all, in order to detect the edge of object, the differential filter is used. And we apply to the labeling algorithm for feature extraction. This algorithm is designed for the defect inspection of pallets ...

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Estimation of Thermal Stresses Induced in Polymeric Thin Film Using Boundary Element Methods

  • Lee, Sang-Soon
    • 한국반도체및디스플레이장비학회:학술대회논문집
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    • 한국반도체및디스플레이장비학회 2002년도 추계학술대회 발표 논문집
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    • pp.27-33
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    • 2002
  • The residual thermal stresses at the interface corner between the elastic substrate and the viscoelastic thin film due to cooling from cure temperature down to room temperature have been studied. The polymeric thin film was assumed to be thermorheologically simple. The boundary element method was employed to investigate the nature of stresses on the whole interface. Numerical results show that very large stress gradients are present at the interface comer and such stress singularity might lead to edge cracks or delamination.

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XRD와 XAS에 의한 TiO2 분말의 상분율 결정 (Estimation of Phase Ratio for TiO2 Powders by XRD and XAS)

  • 나사균;이연승
    • 한국세라믹학회지
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    • 제49권5호
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    • pp.469-474
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    • 2012
  • The crystallinity and phase ratio of anatase to rutile in $TiO_2$ were estimated by x-ray diffraction (XRD) and x-ray absorption spectroscopy (XAS). Traditionally, the structural characterization of $TiO_2$ powders has been carried out by XRD techniques, which are comparatively easy in use and analysis. However, materials with amorphous phase, nano-sized or nano-structured crystallinities cannot be fully characterized by XRD because XRD analysis has a limit for abnormal contributions of the nano-crystal such as the surface contribution. From the comparison with the experimental and calculated Ti K-edge XAS spectra, we found the possibility of efficient estimation in the crystalinites and the phase ratio of anatase to rutile for nano-sized $TiO_2$ mixture.

연속 항공영상에서의 Image Registration (Image Registration of Aerial Image Sequences)

  • 강민석;김준식;박래홍;이쾌희
    • 전자공학회논문지B
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    • 제29B권4호
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    • pp.48-57
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    • 1992
  • This paper addresses the estimation of the shift vector from aerial image sequences. The conventional feature-based and area-based matching methods are simulated for determining the suitable image registration scheme. Computer simulations show that the feature-based matching schemes based on the co-occurrence matrix, autoregressive model, and edge information do not give a reliable matching for aerial image sequences which do not have a suitable statistical model or significant features. In area-based matching methods we try various similarity functions for a matching measure and discuss the factors determining the matching accuracy. To reduce the estimation error of the shift vector we propose the reference window selection scheme. We also discuss the performance of the proposed algorithm based on the simulation results.

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2차 모형의 경제적 추정을 위한 소형실험계획의 활용 (Implementation of Small Sized Designs for Economic Estimation of Second-Order Models)

  • 김정숙;변재현
    • 한국경영과학회:학술대회논문집
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    • 한국경영과학회 2006년도 추계학술대회
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    • pp.531-534
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    • 2006
  • Response surface methodology (RSM) is a useful collection of experimentation techniques for developing, improving, and optimizing products and processes. When we are to estimate second-order regression model and optimize quality characteristic by RSM, central composite designs and Box-Behnken designs are widely in use. However, in developing cutting-edge products, it is very crucial to reduce the time of experimentation as much as possible. In this paper small-sized second-order designs are introduced and their estimation abilities are compared in terms of D-optimality, A-optimality, and variance of regression coefficients, ease of experimentation, number of experiments. Then we present a guideline of using specific designs for specific experimentation circumstances. The result of this study will be beneficial to experimenters who face experiments which are expensive, difficult, or time-consuming.

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무한원점을 이용한 주행방향 추정과 장애물 검출 (The course estimation of vehicle using vanishing point and obstacle detection)

  • 정준익;최성구;노도환
    • 전자공학회논문지S
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    • 제34S권11호
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    • pp.126-137
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    • 1997
  • This paper describes the algorithm which can estimate road following direction and deetect obstacle using a monocular vision system. This algorithm can estimate the course of vehicle using the vanishing point properties and detect obstacle by statistical method. The proposed algorithm is composed of four steps, which are lane prediction, lane extraction, road following parameter estimation and obstacle detection. It is designed for high processing speed and high accuracy. The former is achieved by a small area named sub-windown in lane existence area, the later is realized by using connected edge points of lane. We would like to present that the new mehod can detect obstacle using the simple statistical method. The paracticalities of the processing speed, the accuracy of the algorithm and proposing obstacle detection method, have been justified through the experiment applied VTR image of the real road to the algorithm.

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구조 추정을 이용한 영상 완성 기법 (Automatic Image Completion Using Structure Estimation)

  • 김형진;이정호;문영식
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.923-924
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    • 2008
  • Image completion is to repair a portion of removed image automatically. In this paper, we propose an image completion technique with inner structure estimation. Our method consists of two steps. An inner structure is first estimated by using sobel edge detector. Then, the removed pixels are repaired using similar patches in the known region. By experimental results, it is shown that our approach works well on natural images.

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표적 크기추정 기술 기반의 CCD 영상 표적 정밀 요격 성능 개선 연구 (A Study on the Target Precision Intercept Algorithm based on the Target Size Estimation at CCD Image Sequence)

  • 정윤식;노신백
    • 제어로봇시스템학회논문지
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    • 제21권1호
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    • pp.52-58
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    • 2015
  • In this paper, The ET-MBEF algorithm is presented for CCD imaging seeker. At the imaging seeker, target size information is important factor for accurate tracking. The MBEF algorithm was proposed to estimate target size at IIR seeker. However, the MBEF algorithm can't be applied at CCD imaginary target size estimation. In order to overcome the problem, we propose ET-MBEF algorithm which based on ET (Edge Template) and MBEF algorithm. The performance of proposed method is tested at target intercept scenario. The experiment results show that the proposed algorithm has the accurate target intercept performance.