• 제목/요약/키워드: edge feature

검색결과 553건 처리시간 0.027초

Methods of analysis for buildings with uni-axial and bi-axial asymmetry in regions of lower seismicity

  • Lumantarna, Elisa;Lam, Nelson;Wilson, John
    • Earthquakes and Structures
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    • 제15권1호
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    • pp.81-95
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    • 2018
  • Most buildings feature core walls (and shear walls) that are placed eccentrically within the building to fulfil architectural requirements. Contemporary earthquake design standards require three dimensional (3D) dynamic analysis to be undertaken to analyse the imposed seismic actions on this type of buildings. A static method of analysis is always appealing to design practitioners because results from the analysis can always be evaluated independently by manual calculation techniques for quality control purposes. However, the equivalent static analysis method (also known as the lateral load method) which involves application of an equivalent static load at a certain distance from the center of mass of the buildings can generate results that contradict with results from dynamic analysis. In this paper the Generalised Force Method of analysis has been introduced for multi-storey buildings. Algebraic expressions have been derived to provide estimates for the edge displacement ratio taking into account the effects of dynamic torsional actions. The Generalised Force Method which is based on static principles has been shown to be able to make accurate estimates of torsional actions in seismic conditions. The method is illustrated by examples of two multi-storey buildings. Importantly, the black box syndrome of a 3D dynamic analysis of the building can be circumvented.

STEREO VISION-BASED FORWARD OBSTACLE DETECTION

  • Jung, H.G.;Lee, Y.H.;Kim, B.J.;Yoon, P.J.;Kim, J.H.
    • International Journal of Automotive Technology
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    • 제8권4호
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    • pp.493-504
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    • 2007
  • This paper proposes a stereo vision-based forward obstacle detection and distance measurement method. In general, stereo vision-based obstacle detection methods in automotive applications can be classified into two categories: IPM (Inverse Perspective Mapping)-based and disparity histogram-based. The existing disparity histogram-based method was developed for stop-and-go applications. The proposed method extends the scope of the disparity histogram-based method to highway applications by 1) replacing the fixed rectangular ROI (Region Of Interest) with the traveling lane-based ROI, and 2) replacing the peak detection with a constant threshold with peak detection using the threshold-line and peakness evaluation. In order to increase the true positive rate while decreasing the false positive rate, multiple candidate peaks were generated and then verified by the edge feature correlation method. By testing the proposed method with images captured on the highway, it was shown that the proposed method was able to overcome problems in previous implementations while being applied successfully to highway collision warning/avoidance conditions, In addition, comparisons with laser radar showed that vision sensors with a wider FOV (Field Of View) provided faster responses to cutting-in vehicles. Finally, we integrated the proposed method into a longitudinal collision avoidance system. Experimental results showed that activated braking by risk assessment using the state of the ego-vehicle and measuring the distance to upcoming obstacles could successfully prevent collisions.

칼라팔레트의 불량 식별을 위한 영상처리 시스템 구현 (Implementation of Image Processing System for the Defect Inspection of Color Polyethylene)

  • 김경민;박중조;송명현
    • 한국정보통신학회논문지
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    • 제5권6호
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    • pp.1157-1162
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    • 2001
  • 본 논문에서는 영상 처리 기법을 이용하여 칼라 팔레트 외형상의 불량품을 식별하는 연구를 수행하고자 한다 먼저 기본적인 팔레트 자동선별시스템의 필요성에 대해 기술하며, 각 샘플링된 팔레트에 대해 영상처리기법을 이용한 불순물 검출 알고리즘을 제안하고자 한다. 또한 이를 상용화할 수 있도록 윈도우환경의 비전처리 프로그램을 제시하였다. 끝으로 본 연구에 대한 평가와 앞으로의 연구과제에 대해 기술하고자 한다.

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StrokePortal: a Complete Stroke Information Resource Based on Oriental and Western Medicine

  • Kim, Jin-Ho;Kim, Young-Uk;Bang, Ok-Sun;Cha, Min-Ho;Park, Young-Kyu;Lee, Sun-Young;Kim, Young-Joo
    • Interdisciplinary Bio Central
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    • 제2권3호
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    • pp.7.1-7.3
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    • 2010
  • Stroke, also called an attack on the brain, is a complex disease that results from the interaction of many genetic and environmental factors. StrokePortal is a comprehensive resource for information on stroke that integrates and provides essential findings regarding stroke pathology, diagnostics, and treatments, based on Oriental and Western medicine. The stroke information was collected from various sources, such as journal articles, books, websites, and news stories, and it was refined, classified, and stored into a relational database system by automatic classification and manual curation. To provide the stored information effectively to users, a specialized retrieval system, based on web interfaces, was implemented. StrokePortal provides cutting-edge information to experts; interested people, including patients and their families; and investigators to broaden their knowledge of effective treatments for patients and offer many preventive measures. It provides a specialized feature with which users can upload their information and opinions to StrokePortal, which will enrich and mature the content even further. StrokePortal is freely accessible at http://genomics.kribb.re.kr/StrokePortal/.

가상 표면 인식을 위한 신경회로망 모델 (A Neural network Model for the Perception of Illusory Surfaces)

  • 정은화;홍경호;김욱현
    • 한국정보처리학회논문지
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    • 제5권1호
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    • pp.236-248
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    • 1998
  • 인간의 시각계는 가상 윤곽(Illusory Contours)을 인식한다. 가상 윤곽이란 물리적으로는 윤곽이 없는 곳에서 주변의 패턴의 영향에 의해 윤곽이 있는 것처럼 느끼는 현상으로서, 이와 같은 현상은 물체 인식에 있어서 일부가 숨어 있는 물체를 그 주위의 정보를 이용해서 보충하면서 인식해 가는 능력과 관계가 있다. 본 논문은 가상 윤곽을 인식하기 위한 것으로, 가상 윤곽에서 추출된 유도 자극으로부터 가상표면을 생성하는 신경회로망 모델을 제안하고 실험을 통해 성능을 확인한다.

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SMD의 위치와 방향 계산 및 검사 알고리듬 : 형태학적 방법과 Hough 변환 방법의 비교 (Positioning and Inspection of SMD : Comparison of Morphological Method and Hough Transform Method)

  • 권준식;최종수
    • 전자공학회논문지B
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    • 제32B권1호
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    • pp.73-84
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    • 1995
  • New morphological positioning algorithm and inspection method are presented and compared with a method by means of the Hough transform. The positioning algorithm is the process of finding the center and the rotated angle of the surface mounted device (SMD). The inspection method is capable of detecting the location of broken or bent leads. In order to obtain the center and the orientation of the SMD rapidly, the Hough transform method utilizes feature points (concave points) and is executed on a DSP board. The proposed morphological method is implemented by using the morphological skeleton subsets, and an ultimate orientation is decided by the Hit-or-Miss transform (HMT). In the inspection process, two inspection methods also are presented. The first method utilizes the morphological methods, i.e., opening and closing. It is performed before the positioning process and called an initial inspection. The second method follows the positioning process and is performed by an inspection of intersections of rulers and the lead edge (or the skeleton). It is a ruling technique which is referred to as a detailed inspection. We find the morphological approach is preciser and faster than the Hough approach by the comparison of the proposed algorithms.

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모바일 플랫폼에서 다중 특징 기반의 이미지 검색 (Image Retrieval using Multiple Features on Mobile Platform)

  • 이용환;조한진;이준환
    • 디지털융복합연구
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    • 제12권6호
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    • pp.237-243
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    • 2014
  • 본 논문에서는 다양한 검색 환경과 모바일 디바이스의 센서 정보를 활용한 모바일 이미지 검색 방법을 제안하고 안드로이드 플랫폼에서 구동하는 검색 시스템을 구현하였다. 설계 개발 시스템은 JPEG 이미지를 대상으로 산업계 표준 메타데이터인 EXIF 속성과 시각적 특징을 결합한 새로운 검색 기술자이며, 검색을 위한 특징 추출 및 유사도 평가 알고리즘을 모바일 환경에 최적화한 이미지 검색 모듈이다. 실험을 통해, 대용량 이미지 데이터셋을 대상으로 안드로이드 폰에서 효율적인 이미지 검색을 수행하였음을 보였다.

거리영상과 밝기영상의 fusion을 이용한 영상분할 (Image Segmentation Based on Fusion of Range and Intensity Images)

  • 장인수;박래홍
    • 전자공학회논문지S
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    • 제35S권9호
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    • pp.95-103
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    • 1998
  • 본 논문에서는 거리영상과 발기영상의 fusion을 이용한 영상분할을 제안한다. Bayes 이론을 기반으로 하여 Markov random field (MRF)로 선험적인 정보를 모델링한다. 거리영상과 밝기영상에서 추출한 특징을 이용하여 maximum a posteriori (MAP) 추정기를 구성한다. 거리영상에서 물체는 국부적인 평면으로 근사되어 각 점마다 평면 계수를 추정해 계수 공간을 구성한다. 밝기영상에서는 ${\alpha}$ 트림드 (${\alpha}$-trimmed) 분산이 밝기특성을 구성한다. 각 공간상의 특징을 에지에 대한 likelihood를 설정하여 구성된 MAP 추정기를 최적화함으로써 영상을 분할한다. 모의실험을 통해 제안된 구조가 그림자, 잡음 그리고 광원의 blurring에 관계없이 영상을 잘 분할한 것을 보였다.

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CRF-Based Figure/Ground Segmentation with Pixel-Level Sparse Coding and Neighborhood Interactions

  • Zhang, Lihe;Piao, Yongri
    • Journal of information and communication convergence engineering
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    • 제13권3호
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    • pp.205-214
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    • 2015
  • In this paper, we propose a new approach to learning a discriminative model for figure/ground segmentation by incorporating the bag-of-features and conditional random field (CRF) techniques. We advocate the use of image patches instead of superpixels as the basic processing unit. The latter has a homogeneous appearance and adheres to object boundaries, while an image patch often contains more discriminative information (e.g., local image structure) to distinguish its categories. We use pixel-level sparse coding to represent an image patch. With the proposed feature representation, the unary classifier achieves a considerable binary segmentation performance. Further, we integrate unary and pairwise potentials into the CRF model to refine the segmentation results. The pairwise potentials include color and texture potentials with neighborhood interactions, and an edge potential. High segmentation accuracy is demonstrated on three benchmark datasets: the Weizmann horse dataset, the VOC2006 cow dataset, and the MSRC multiclass dataset. Extensive experiments show that the proposed approach performs favorably against the state-of-the-art approaches.

Comparative study of photoluminescences for Zn-polar and O-polar faces of single-crystalline ZnO bulks

  • 오동철;김동진;배창환;구경완;박승환;야오다까후미
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2010년도 하계학술대회 논문집
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    • pp.39-39
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    • 2010
  • The authors have an extensive study of photoluminescences for Zn-polar and O-polar faces of single-crystalline ZnO bulks. In the photoluminescence (PL) spectra at 10 K, Zn-polar and O-polar faces show a common emission feature: neutral donor-bound excitons and their longitudinal-optical (LO) phonon replicas are strong, and free excitons are very weak. However, in the PL spectra at room temperature (RT), Zn-polar and O-polar faces show extremely different emission characteristics: the emission intensity of Zn-polar face is 30 times larger than that of O-polar face, and the band edge of Zn-polar face is 33 meV red-shifted from that of O-polar face. The temperature dependence of photoluminescence indicates that the PL spectra at RT are closely associated with free excitons and their phonon-assisted annihilation processes. As a result, it is found that the RT PL spectra of Zn-polar face is dominated by the first-order LO phonon replica of A free excitons, while that of O-polar face is determined by A free excitons. This is ascribed that Zn-polar face has larger exciton-phonon coupling strength than O-polar face.

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