• Title/Summary/Keyword: projection

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A SYSTEM OF NONLINEAR PROJECTION EQUATIONS WITH PERTURBATION IN HILBERT SPACES

  • Zhou, Li-Wen;Cho, Yeol-Je;Huang, Nan-Jing
    • East Asian mathematical journal
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    • v.24 no.2
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    • pp.191-199
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    • 2008
  • In this paper, we introduce and studied a system of nonlinear projection equations with perturbation in Hilbert spaces. By using the fixed point theorem, we prove an existence of solution for this system of nonlinear projection equations. We construct an algorithm for approximating the solution of the system of nonlinear projection equations with perturbation and show that the iterative sequence generated by the algorithm converges to the solution of the system of nonlinear projection equations with perturbation under some suitable conditions.

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The Methodology in Historical Demography at the Cambridge Group (역사 인구학 방법론의 현황)

  • 이흥탁
    • Korea journal of population studies
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    • v.12 no.2
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    • pp.56-68
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    • 1989
  • The methodology in historical demography comprises the three core areas the family reconstitution method at the Institut National d' Ftudes Demographiques(I.N.E.D), the back projection at the Cambridge Group for the History of PopuJation and Social Struc-ture(HPSS). and the household-pattern analysis at the Cambridge Group and at the California Institute of Technology. The paper presents an outline of the family reconstitu-tion method and discusses the problems, both theoretical and methodological, arising from the problematic back projection vis-a-vis the usual inverse projection developed by Ronald D. Lee at Berkeley. Recent developments in the tield of the generalized inverse projection method designed 10 supplement the defects in the back projection and the inverse projection are presented. and for ease of explanation of the parish register data for the family reconstitution form (FRE). pre-modern Korean household register data are presented along with the parish register data of England and Wales that constitute the backbone of historical demography in pre-modern Europe. Possibilities of exploring the household pattern analysis method based on the Laslett-Hammel classification scheme for the mid-eighteenth-century Korean household register data are suggested.

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A Study on the Quantitative Analysis of View by the Projection Method in the Residential Buildings (주거용 건물에서의 투영법에 의한 조망의 정량적 분석에 관한 연구)

  • 김용이;김광우
    • Journal of the Korean housing association
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    • v.14 no.5
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    • pp.37-46
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    • 2003
  • The quantitative analysis of view tells how surroundings and sky are showed, and requires understanding of visual perception and three dimensional information of buildings. The visual perception and the existing projection methods for view analysis are examined. The results of this study are as follows: The visual perception on the size is determined by the visual angle, which can be described as a solid angle. The analysis of view by planar projection can be narrow-sighted according to the size of the window and the location of the viewpoint, which will cause the obstacles in the normal direction of the window interfere the view. For the analysis of view by fisheye projection, the area around the focus point is calculated wider than other areas, and so the view ratio depends on the position of the focus point. When analyzing sky view by dividing the sky vault into the differential area, the distortion by projection can be minimized.

Color Line Projection

  • Park Joung-Wook;Yoo Jae-Doug;Lee Kwan-Heng
    • Proceedings of the Korean Information Science Society Conference
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    • 2006.06a
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    • pp.100-102
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    • 2006
  • 본 논문에서는 반짝이는 물체를 촬영하여 획득된 이미지로부터 반짝이는 특성을 제거하기 위한 방법으로 color line projection을 제안한다. Color line projection 이란 반짝이는 물체에 대한 color line이 생성되어 있다고 가정하면 하이라이트를 제거하거나 반짝이는 특성을 제거하기 위해 반짝이는 성분을 지닌 색을 specular color line을 따라 diffuse color line에 투영하는 방법이다. 이를 활용하기 위해서는 촬영된 단일 색상을 잘 표현하는 color line이 필요하고 반짝이는 특성을 제거하려는 대상이 되는 색의 구분하는 작업이 선행되어야 한다. 본 논문에서는 color line projection에 대한 개념과 구현하기 위한 방법을 제안하고 이를 활용하는 예제로 반짝이는 성분을 지닌 픽셀들로부터 반짝이는 특성을 제거하는 방법에 적용하는 방법을 제시할 것이다. 또한 결과에서 color line projection이 아닌 다른 방법을 통해 반짝이는 특성을 제거한 결과와 비교함으로써 color line projection의 장점을 실제 이미지를 통해 검증할 것이다.

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Algorithm for Moving Object Tracking from Moving Camera Using Histogram Projection (히스토그램 프로젝션을 이용한 움직이는 카메라로 부터의 이동물체 추적 알고리즘)

  • 설성욱;이희봉;김효성;남기곤;이철헌
    • Journal of the Institute of Convergence Signal Processing
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    • v.2 no.4
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    • pp.38-45
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    • 2001
  • In this paper, we propose an algorithm for moving object tracking from moving camera using histogram back program intersection(HI) and XY-projection The proposed method segments objects using histogram back projection, matches tracing objects using histogram intersection and extracts them using XY- projection. Through the simulation this paper shows that the proposed method segments. matches and tracks objects without significant error image sequences obtained by moving camera.

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Development of an Immersive VR Display System Supporting Continuous Arrangement of Multiple Screens (다중스크린의 연속적인 배치를 지원하는 몰입형 가상환경 디스플레이 시스템의 개발)

  • 남상훈;채영호;강재훈
    • Korean Journal of Computational Design and Engineering
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    • v.7 no.1
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    • pp.18-26
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    • 2002
  • The suggested modular projection system can have flexible arrangements of screens. Modular and continuous arrangements of the display system enable us to modify the screen configuration easily, so that the system can be used in various applications. The image of each screen is calculated automatically by using window projection and the tracked position of the viewer. This system also uses the off-axis stereoscopic projection for the seamless stereoscopic edge blending of multiple connections of screens. The system has been successfully tested for the general navigation model and the CAU driving simulator with motion platform.

Inactive Regions Padding Methods for Rotated Sphere Projection of 360 Video

  • Yoon, Yong-Uk;Kim, Hyun-Ho;Kim, Jae-Gon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2018.06a
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    • pp.200-201
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    • 2018
  • In the workflow of 360 video coding of JVET (Joint Video Experts Team), firstly the 360 videos are projected onto the 2D plane with diverse projection formats, such as Equi-Rectangular Projection (ERP), Cubemap Projection (CMP), Rotated Sphere Projection (RSP), etc. The projection format of RSP has inactive regions in the converted 2D plane. The inactive regions may cause visual artifact as well as the reduction of the coding efficiency due to discontinuity at boundaries between active and inactive regions. In this paper, to overcome these problems, the inactive regions are padded by using two types of adjacent pixels. Then padded regions of RSP are blended with inactive regions padded by proposed method. The experimental results demonstrate that, in terms of end-to-end WS-PSNR-NN, the proposed method achieves 0.1% BD-rate reduction. In addition, the visual artifacts along the borders between discontinuous faces are noticeably reduced.

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Implementation of Nonlinear SVM for HD Projection TV (HD Projection TV를 위한 비선형 SVM 회로의 구현)

  • Lee, Gwang-Sun;Gwon, Yong-Dae;Lee, Geon-Il;Song, Gyu-Ik;Choe, Deok-Gyu;Han, Chan-Ho;Kim, Eun-Su
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.38 no.2
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    • pp.191-198
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    • 2001
  • As a method to compensate the deterioration of the picture quality which was caused by beam profile characteristic in the CRT and the projection screen of HD projection TV, a linear scan velocity modulation(SVM) method has been employed, whose modulation velocity is linearly proportional to the variation in the video signal amplitude. However, the effect of picture quality improvement is not uniform with video signal amplitude in the linear SVM. In this paper, for the optimum SVM effect, we analyze the beam profile characteristic on the HD projection screen and we analyze the SVM effect as function of the differentiated pulse width, the differentiated pulse amplitude and the input signal amplitude. Finally we confirm that the nonlinear SVM method is necessary to get uniform image compensation in the HD projection TV, and we implement the nonlinear SVM circuit. The performance of the realized SVM circuit with nonlinear amplitude transfer characteristic is confirmed as uniform improvements in picture quality.

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Imaging Method in Time Domain for Bistatic Forward-Looking Radar in Short Range Application (근거리 Bistatic 전방 관측 레이다의 시간 영역 영상화 기법)

  • Sun, Sun-Gu;Cho, Byung-Lae;Lee, Jung-Soo;Park, Gyu-Churl;Ha, Jong-Soo;Han, Seung-Hoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.11
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    • pp.1054-1062
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    • 2011
  • This study describes the time domain imaging algorithm which can be well applied to short-range UWB(ultra wideband) bistatic radar. In the imaging method of SAR technology, the frequency domain method is well applied to the areas which satisfy far-field condition. However in the near-field environment, the image quality is not good due to phase error. However back-projection method based on time domain is well applied to short-range imaging radar. Meanwhile because its processing time is very long, real time-processing is very difficult. To resolve this problem FFBP(Fast Factorized Back-Projection) was proposed. Using the raw data gathered on field we implemented back-projection and FFBP method. Then image quality and processing time were analyzed using these methods.

Impact of Fiber Projection from GMT-Sheet Moldings on Surface Unevenness (GMT-Sheet 성형품의 표면요철에 미치는 섬유돌출의 영향)

  • Kim, Hyoung-Seok;Kim, Jin-Woo;Kim, Yong-Jae;Lee, Dong-Gi
    • Composites Research
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    • v.24 no.6
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    • pp.31-36
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    • 2011
  • According to the evaluation on GMT-sheet by molding conditions, fiber projection on the moldings surface was investigated. Fiber projection is one of the major defects on moldings surface due to matrix shrinkage. That is, fiber projection happens from different shrinkage of matrix and glass fiber. Height of fiber projection from moldings surface becomes smaller when molding pressure is higher during holding pressure and cooling process. Height of fiber projection is dominantly affected by molding pressure. With consideration of molding pressure, the formation of surface unevenness and change in fiber projection height was elucidated. In addition, coating layer is effective to suppress surface defects, and there is no fiber projection or crack in case that coating is applied. Coating layer improves surface roughness up to the level of the polypropylene which is a single material.