• Title/Summary/Keyword: Object Boundary Point

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Improvement of Active Contour Model for Detection of Pulmonary Region in Medical Image (의학 영상에서 폐 영역 검출을 위한 Active Contour 모델 개선)

  • Kwon Y. J.;Won C. H.;Park H. J.;Lee J. H.;Lee S. H.;Cho J. H.
    • Journal of Korea Multimedia Society
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    • v.8 no.3
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    • pp.336-344
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    • 2005
  • In this paper, we extracted the contour of lung parenchyma on EBT images with the improved active contour model. The objects boundary in conventional active contour model can be extracted by controlling internal energy and external energy as energy minimizing form. However, there are a number of problems such as initialization and the poor convergence about concave part. Expecially, contour can not enter the concave region by discouraging characteristic about stretching and bending in internal energy. We controlled internal energy by moving local perpendicular bisector point of each control point in the contour and implemented the object boundary by minimizing energy with external energy The convergence of concave part could be efficiently implemented toward lung parenchyma region by this internal energy and both lung images for initial contour could also be detected by multi-detection method. We were sure this method could be applied detection of lung parenchyma region in medical image.

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Measurement of Structural Properties of PLA Filament as a Supplier of 3D Printer (3D 프린터에 공급되는 PLA 필라멘트의 물성치 측정)

  • Choi, Won;Woo, Jae-Hyeong;Jeon, Jeong-bae;Yoon, Seong-soo
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.6
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    • pp.141-152
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    • 2015
  • Most of agricultural structures are consisted of complex components and exposed to various boundary conditions. There have been no ways to express those structures exactly for model experiment. As an alternative, 3D printer can produce any type of solid model. However, there are limited informations related to structural experiments using 3D printer. The object of this study gives the basic informations to structural engineers who try to use 3D printer for model experiment. When PLA was used as a supplier for 3D printer, the outcomes showed less heat deformation to compare with ABS. To test the material properties, two kinds of experiments (three-point flexibility test and compression test) were executed using universal testing machine. In three-point flexibility test, plastic hinge and its deformation were developed as observed in material such as steel. The behavior was in a linear elastic state, and elastic bending modulus and yield force were evaluated. In the compression test using unbraced columns with hinge-hinge boundary condition, the constant yield forces were observed regardless of different lengths in all columns with same section size, whereas the compressive elastic modulus was increased as the length of column was increased. The suggested results can be used for model experiments of various agricultural structures consisted of single material.

Edge Detection using Genetic Algorithm (유전자 알고리즘을 이용한 윤곽선 추출)

  • 박찬란;이웅기
    • Journal of the Korea Society of Computer and Information
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    • v.3 no.2
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    • pp.85-97
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    • 1998
  • The existing edge detection methods can not represent the real edge of object at fitting point or detect the edge which has unsufficient connecting trait. Especially, the two-fold thick edge detected by these methods cannot coincide real boundary of subject and it's location. To overcome these problems, we introduce the Genetic Algorithm(GA) in edge detection. The energy function is the value of fixel's satisfaction degree to edge condition. And it consists of the fitness value to image formation type, fitness value to connecting trait to it's neighboring edge and evalulation function which can represents the edge at fitting point as one fixel. This method is superior to remove the noise in edge detection than the existing methods. And it also detects the clear and exact edge because it can find the one fixel which is located at fitting point and has strong connecting trait.

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ALGEBRAIC CORRECTION FOR METAL ARTIFACT REDUCTION IN COMPUTED TOMOGRAPHY

  • Jeon, Kiwan;Kang, Sung-Ho;Ahn, Chi Young;Kim, Sungwhan
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.18 no.2
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    • pp.157-166
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    • 2014
  • If there are metals located in the X-ray scanned object, a point outside the metals has its range of projection angle at which projections passing through the point are disturbed by the metals. Roughly speaking, this implies that attenuation information at the point is missing in the blocked projection range. So conventional projection completion MAR algorithms to use the undisturbed projection data on the boundary of the metaltrace is less efficient in reconstructing the attenuation coefficient in detailed parts, in particular, near the metal region. In order to overcome this problem, we propose the algebraic correction technique (ACT) to utilize a pre-reconstructed interim image of the attenuation coefficient outside the metal region which is obtained by solving a linear system designed to reduce computational costs. The reconstructed interim image of the attenuation coefficient is used as prior information for MAR. Numerical simulations support that the proposed correction technique shows better performance than conventional inpainting techniques such as the total variation and the harmonic inpainting.

Vibration analysis of a Timoshenko beam carrying 3D tip mass by using differential transform method

  • Kati, Hilal Doganay;Gokdag, Hakan
    • Structural Engineering and Mechanics
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    • v.65 no.4
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    • pp.381-388
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    • 2018
  • Dynamic behaviour of beam carrying masses has attracted attention of many researchers and engineers. Many studies on the analytical solution of beam with concentric tip mass have been published. However, there are limited works on vibration analysis of beam with an eccentric three dimensional object. In this case, bending and torsional deformations of beam are coupled due to the boundary conditions. Analytical solution of equations of motion of the system is complicated and lengthy. Therefore, in this study, Differential Transform Method (DTM) is applied to solve the relevant equations. First, the Timoshenko beam with 3D tip attachment whose centre of gravity is not coincident with beam end point is considered. The beam is assumed to undergo bending in two orthogonal planes and torsional deformation about beam axis. Using Hamilton's principle the equations of motion of the system along with the possible boundary conditions are derived. Later DTM is applied to obtain natural frequencies and mode shapes of the system. According to the relevant literature DTM has not been applied to such a system so far. Moreover, the problem is modelled by Ansys, the well-known finite element method, and impact test is applied to extract experimental modal data. Comparing DTM results with finite element and experimental results it is concluded that the proposed approach produces accurate results.

A Study on the Edge Detection using Region Segmentation of the Mask (마스크의 영역 분할을 이용한 에지 검출에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.3
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    • pp.718-723
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    • 2013
  • In general, the boundary portion of the background and objects are the rapidly changing point and an important elements to analyze characteristics of image. Using these boundary parts, information about the position or shape of an object in the image are detected, and many studies have been continued in order to detect it. Existing methods are that implementation of algorithm is comparatively simple and its processing speed is fast, but edge detection characteristics is insufficient because weighted values are applied to all the pixels equally. Therefore, in this paper, we proposed an algorithm using region segmentation of the mask in order to adaptive edge detection according to image, and the results processed by proposed algorithm indicated superior edge detection characteristics in edge area.

A Critical Study about the Correlation between the Body without Organ and Blurring Boundary Fashion - Focusing on Philosophical and Sociological Discourses about the Body and the Desire - (기관 없는 신체와 탈영토화 된 패션 사이의 상관관계에 대한 비판적 고찰 - 철학적, 사회학적 신체 담론과 욕망이론을 중심으로 -)

  • Yang, Hee-Young;Lee, Myung-Hee
    • The Research Journal of the Costume Culture
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    • v.18 no.5
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    • pp.824-841
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    • 2010
  • In 21st century, subordinated relationship of fashion from the body has been disappearing, and fashion is understood as variable and creative field. This research aims at analysis about the relationship between the body and fashion depending on the theories about the authority and the desire. So, this utilizes between theoretical study and empirical analysis. For concentrated study, research period limits from 2000 to the present time 2010. Contemporary body and fashion have being changed into various forms and values, become complex and de-territory. Especially, body is symbol of ambivalence eroticism that gives point to sexual property, and the object of fetishism and machine having a desire. This study's purpose draw a parallel with between the limits of contemporary body that couldn't be rid of the capital and desire, and the liberty of fashion that escape from the body's influence has being changed independent and fluid space. This research's results are as follow as; contemporary de-territory fashion is expressed as 1) symbol of the object and physical material property, 2) self-transcendental instrument fashion, 3) independent spatial molding, 4) de-centering fashion.

Parcel Boundary Demarcation in Residential Area Using High Resolution Aerial Images (고해상도 항공영상을 이용한 주거지역 필지경계 설정에 관한 연구)

  • Park, Chiyoung;Lee, Jaeone
    • Spatial Information Research
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    • v.23 no.1
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    • pp.59-68
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    • 2015
  • As part of an effort to leap smart cadastre system by doing rearrangement of various mismatches in the land register, the cadastre renovation project is being recently conducted. In response to this demand, this paper proposes an image-based rapid parcel boundary demarcation plan using the high resolution aerial image with a GSD (Ground Sample Distance) of 5cm that matches to real ground boundary situation in residential area. To review the feasibility and accuracy of this proposed methodology, we compared the accuracy of parcel boundary point and parcel area extracted from the digital stereo plotting on the basis of results of cadastral boundary surveying and land register over the selected two test areas. The comparative accuracy result of all boundary points by digital stereo plotting is satisfied with accuracy requirement according to the criteria of the enforcement regulation of cadastral surveying, whereas it exceeded allowable error of ${\pm}0.07m$, more strictly specified in the Special Act on Cadastral Renovation. And about 20% of the total 70 parcels extracted by digital plotting are out of area tolerance in Jecheon study area, and 10% of the total 19 parcels in Suwon study area. The parcels exceeding accuracy limit are mostly due to the occlusion caused by building roof or eaves, and the obstacles such as trees existing on the boundary. Furthermore, an object identification is impossible in image because of vague boundary reference in case of nonexistence of man-made structures or natural features. Therefore, the utilization of boundary identification stickers is recommended as a solution for these types of land parcel.

A Study on Object Segmentation Using Snake Algorithm in Disparity Space (변이공간에서 스네이크 알고리즘을 이용한 객체분할에 관한 연구)

  • Yu Myeong-Jun;Kim Shin-Hyoung;Jang Jong Whan
    • The KIPS Transactions:PartB
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    • v.11B no.7 s.96
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    • pp.769-778
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    • 2004
  • Object segmentation is a challenging Problem when the background is cluttered and the objects are overlapped one another. Recent develop-ment using snake algorithms proposed to segment objects from a 2-D Image presents a higher possibilityfor getting better contours. However, the performance of those snake algorithms degrades rapidly when the background is cluttered and objects are overlapped one another, Moreover, the initial snake point placement is another difficulty to be resolved. Here, we propose a novel snake algorithm for object segmentation using disparity information taken from a set of stereo images. By applying our newly designed snake energy function defined in the disparity space, our algorithmeffectively circumvents the limitations found in the previous methods. The performance of the proposed algorithm has been verified by computer simulation using various stereo image sets. The experiment results have exhibited a better performance over the well-known snake algorithm in terms of segmentation accuracy.

Object Boundary Point Detection Using Background Image Change (배경화면 변화를 이용한 객체의 윤곽점 검출)

  • Back, Ju-Ho;Lee, Chang-Soo;Oh, Hae-Seok
    • Proceedings of the Korea Information Processing Society Conference
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    • 2003.05a
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    • pp.563-566
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    • 2003
  • 인터넷 시대에 접어들면서 웹 카메라를 이용한 보안 시스템의 개발이 활발하다 원격지에 설치된 카메라가 보내준 영상을 통하여 현재의 상황을 파악할 수 있으며 적절한 조치를 웹을 통해 취할 수 있다. 본 논문에서는 카메라로부터 입력되어지는 입력영상과 배경영상의 차를 이용하여 움직임 검출하는 방법을 제안한다. 또한 배경영상은 시간에 따라 변화하기 때문에 변화된 시점부터 배경이미지 픽셀을 교체 해준다. 카메라에서 받아오는 영상을 배경영상과 입력영상으로 구분 한 다음 두 영상의 차를 구하여 영상의 변화점을 찾는다. 픽셀 검사는 모든 픽셀을 연산에 참여하는 방식을 탈피하여 일정한 간격을 두고 이미지의 픽셀을 검색하여 효율적인 객체의 윤곽점을 추출한다.

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