• Title/Summary/Keyword: space intersection

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A Study on a Morphological Identification of Phragmitis Rhizoma and Phragmitis Caulis (노근(蘆根)과 위경(葦莖)의 형태(形態) 감별에 관한 연구)

  • Beom, Hui-Byeon;Han, Sin-Hee;Lee, Young-Jong
    • The Korea Journal of Herbology
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    • v.21 no.4
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    • pp.177-181
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    • 2006
  • Objectives : External form and internal intersection of Phragmites communis were observed by the parts of usage (leaves, stems, and roots). Methods : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and then observed and photographed by olymphus-BHT. Results : 1. The intersection of Phragmitis Folium was typically characterized as Gramineae plants, which was perfectly distinguished with Phragmitis Rhizoma and Phragmitis Caulis. 2. The cortex of Phragmitis Rhizoma has a large rectangular pore space, but Phragmitis Caulis does not. Conclusion : Phragmitis Folium, Phragmitis Caulis, and Phragmitis Rhizoma can be distinguished by microscope.

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Efficient Calculation of Distance Fields Using Cell Subdivision (셀 분할을 이용한 거리장의 효율적 계산)

  • Yoo, Dong-Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.3
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    • pp.147-156
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    • 2008
  • A new approach based on cone prism intersection method combined with sorting algorithm is proposed for the fast and robust signed distance field computation. In the method, the space bounding the geometric model composed of triangular net is divided into multiple smaller cells. For the efficient calculation of distance fields, valid points among the triangular net which will generate minimum distances with current cell are selected by checking the intersection between current cell and cone prism generated at each point. The method is simple to implement and able to achieve an order of magnitude improvement in the computation time as compared to earlier approaches. Further the method is robust in handling the traditional sign problems. The validity of the suggested method was demonstrated by providing numerous examples including Boolean operation, shape deformation and morphing of complex geometric models.

A Study on the Minimization of Cutting Slope around Tunnel Portal (지형과 사교하는 갱구부의 비탈면 최소화 방안 연구)

  • Jeong Kwan Sik;Park Ji Hoon;Kim Gun Ho;Lee Wan Jae
    • 한국터널공학회:학술대회논문집
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    • 2005.04a
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    • pp.359-371
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    • 2005
  • The Cutting slope is to be minimized when a tunnel meets the contour of slope terrain at a right angle around its portal. However, a tunnel portal has been generally installed at a right angle to the longitudinal axis of a tunnel with no consideration of the intersection angle with the slope terrain. This sometimes tended to cause huge cutting slope that resulted in many disadvantage in terms of safty, economy and environment. Therefore, the minimization of cutting slope is studied by taking the intersection angle into account, and the result is compared with that by the conventional method. In addition a design method for the inclined portal to the tunnel axis is proposed through 3D-FEM analysis, also the applicable ground condition is suggested.

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Color-based Image Retrieval using Color Segmentation and Histogram Reconstruction

  • Kim, Hyun-Sool;Shin, Dae-Kyu;Kim, Taek-Soo;Chung, Tae-Yun;Park, Sang-Hui
    • KIEE International Transaction on Systems and Control
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    • v.12D no.1
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    • pp.1-6
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    • 2002
  • In this study, we propose the new color-based image retrieval technique using the representative colors of images and their ratios to a total image size obtained through color segmentation in HSV color space. Color information of an image is described by reconstructing the color histogram of an image through Gaussian modelling to its representative colors and ratios. And the similarity between two images is measured by histogram intersection. The proposed method is compared with the existing methods by performing retrieval experiments for various 1280 trademark image database.

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High Accuracy Vision-Based Positioning Method at an Intersection

  • Manh, Cuong Nguyen;Lee, Jaesung
    • Journal of information and communication convergence engineering
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    • v.16 no.2
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    • pp.114-124
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    • 2018
  • This paper illustrates a vision-based vehicle positioning method at an intersection to support the C-ITS. It removes the minor shadow that causes the merging problem by simply eliminating the fractional parts of a quotient image. In order to separate the occlusion, it firstly performs the distance transform to analyze the contents of the single foreground object to find seeds, each of which represents one vehicle. Then, it applies the watershed to find the natural border of two cars. In addition, a general vehicle model and the corresponding space estimation method are proposed. For performance evaluation, the corresponding ground truth data are read and compared with the vision-based detected data. In addition, two criteria, IOU and DEER, are defined to measure the accuracy of the extracted data. The evaluation result shows that the average value of IOU is 0.65 with the hit ratio of 97%. It also shows that the average value of DEER is 0.0467, which means the positioning error is 32.7 centimeters.

Stability Analysis on the Intersection Area of Subway Tunnels by Observational Method (계측에 의한 지하철터널 교차부의 안정성 검토)

  • Kim Chee-Hwan
    • Tunnel and Underground Space
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    • v.15 no.1 s.54
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    • pp.71-79
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    • 2005
  • The stability of the intersection area of two tunnels is analyzed by observational method. The depth from ground surface to the intersected area is shallow and the geology around the area consists of soil and/or weathered rock. The tunnel is supported by reinforced protective umbrella method with 12 m long 3-layer steel-pipes and the intersected area is additionally reinforced with 6 m long rockbolts. The measured displacements are converged and mechanical stability of the intersected area of two tunnels is confirmed; tunnel arch settles to 6-7 mm at the crown and the sidewalls converges to about 5 mm. So based on the displacement measurements, the supporting system for the tunnel intersection proves to be effective to not only reduce the deformation of tunnels but also maintain the stability of tunnels.

Efficient Storage Management Scheme for Graph Historical Retrieval (그래프 이력 데이터 접근을 위한 효과적인 저장 관리 기법)

  • Kim, Gihoon;Kim, Ina;Choi, Dojin;Kim, Minsoo;Bok, Kyoungsoo;Yoo, Jaesoo
    • The Journal of the Korea Contents Association
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    • v.18 no.2
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    • pp.438-449
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    • 2018
  • Recently, various graph data have been utilized in various fields such as social networks and citation networks. As the graph changes dynamically over time, it is necessary to manage the graph historical data for tracking changes and retrieving point-in-time graphs. Most historical data changes partially according to time, so unchanged data is stored redundantly when data is stored in units of time. In this paper, we propose a graph history storage management method to minimize the redundant storage of time graphs. The proposed method continuously detects the change of the graph and stores the overlapping subgraph in intersection snapshot. Intersection snapshots are connected by a number of delta snapshots to maintain change data over time. It improves space efficiency by collectively managing overlapping data stored in intersection snapshots. We also linked intersection snapshots and delta snapshots to retrieval the graph at that point in time. Various performance evaluations are performed to show the superiority of the proposed scheme.

The metric approximation property and intersection properties of balls

  • Cho, Chong-Man
    • Journal of the Korean Mathematical Society
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    • v.31 no.3
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    • pp.467-475
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    • 1994
  • In 1983 Harmand and Lima [5] proved that if X is a Banach space for which K(X), the space of compact linear operators on X, is an M-ideal in L(X), the space of bounded linear operators on X, then it has the metric compact approximation property. A strong converse of the above result holds if X is a closed subspace of either $\elll_p(1 < p < \infty) or c_0 [2,15]$. In 1979 J. Johnson [7] actually proved that if X is a Banach space with the metric compact approximation property, then the annihilator K(X)^\bot$ of K(X) in $L(X)^*$ is the kernel of a norm-one projection in $L(X)^*$, which is the case if K(X) is an M-ideal in L(X).

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Content-Based Image Retrieval using Scale-Space Theory (Scale-Space 이론에 기초한 내용 기반 영상 검색)

  • 오정범;문영식
    • Journal of KIISE:Software and Applications
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    • v.26 no.1
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    • pp.150-150
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    • 1999
  • In this paper, a content-based image retrieval scheme based on scale-space theory is proposed. The existing methods using scale-space theory consider all scales for image retrieval,thereby requiring a lot of computation. To overcome this problem, the proposed algorithm utilizes amodified histogram intersection method to select candidate images from database. The relative scalebetween a query image and a candidate image is calculated by the ratio of histograms. Feature pointsare extracted from the candidates using a corner detection algorithm. The feature vector for eachfeature point is composed of RGB color components and differential invariants. For computing thesimilarity between a query image and a candidate image, the euclidean distance measure is used. Theproposed image retrieval method has been applied to various images and the performance improvementover the existing methods has been verified.

Scanline Based Metric for Evaluating the Accuracy of Automatic Fracture Survey Methods (자동 균열 조사기법의 정확도 평가를 위한 조사선 기반의 지표 제안)

  • Kim, Jineon;Song, Jae-Joon
    • Tunnel and Underground Space
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    • v.29 no.4
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    • pp.230-242
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    • 2019
  • While various automatic rock fracture survey methods have been researched, the evaluation of the accuracy of these methods raises issues due to the absence of a metric which fully expresses the similarity between automatic and manual fracture maps. Therefore, this paper proposes a geometry similarity metric which is especially designed to determine the overall similarity of fracture maps and to evaluate the accuracy of rock fracture survey methods by a single number. The proposed metric, Scanline Intersection Similarity (SIS), is derived by conducting a large number of scanline surveys upon two fracture maps using Python code. By comparing the frequency of intersections over a large number of scanlines, SIS is able to express the overall similarity between two fracture maps. The proposed metric was compared with Intersection Over Union (IoU) which is a widely used evaluation metric in computer vision. Results showed that IoU is inappropriate for evaluating the geometry similarity of fracture maps because it is overly sensitive to minor geometry differences of thin elongated objects. The proposed metric, on the other hand, reflected macro-geometry differences rather than micro-geometry differences, showing good agreement with human perception. The metric was further applied to evaluate the accuracy of a deep learning-based automatic fracture surveying method which resulted as 0.674 (SIS). However, the proposed metric is currently limited to 2D fracture maps and requires comparison with rock joint parameters such as RQD.