• Title/Summary/Keyword: Plane Projection

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Pseudo Stereophonic Acoustic Echo Cancellar using Hyper-plane Projection Algorithm (Hyper-plane Projection 알고리듬을 이용한 의사 스테레오 음향 반향 제거기)

  • 박필구
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1998.06e
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    • pp.173-176
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    • 1998
  • 스테레오 음향 반향 제거기에서 발생하는 주요한 문제점들은 모노 환경에서와는 다르게 반향 경로 시스템의 긴 임펄스 응답으로 인한 느린 수렴속도와 원단화자 주위의 환경변화에 의한 최적해의 변화 등을 등 수 있다. 이러한 문제점들을 극복하기 위해 본 논문은 전송실에서의 환경 변화에 의한 반향 제거 성능저하와 저속의 수렴속도 및 과다한 계산량의 문제점을 해결하기 위하여 본 논문에서는 전송실의 환경 변화에 강인하고 계산량을 줄일 수 있는 Hyper-plane projection 알고리듬을 이용한 의사 스테레오 음향 반향 제거기를 제안한다.

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Sensitivita Analysis and Optimal desing of plane Vehicle Frame Structures (평면 차체프레임구조물의 민감도해석 및 최적설계)

  • 이종선
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.5 no.4
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    • pp.74-81
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    • 1996
  • This paper is to estimate sizing design sensitivity of linear and nonlinear vehicle frame structure using structural ananlysis result from ANSYS. Using design sensitivity results, optimal design of plane vehicle frame structure with buckling constraint is carried out the gradient projection method. Optimal design results are compares gradient projection method resrult with SUMT result.

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Useful Image Back-projection Properties in Cameras under Planar and Vertical Motion (평면 및 수직 운동하는 카메라에서 유용한 영상 역투영 속성들)

  • Kim, Minhwan;Byun, Sungmin
    • Journal of Korea Multimedia Society
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    • v.25 no.7
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    • pp.912-921
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    • 2022
  • Autonomous vehicles equipped with cameras, such as robots, fork lifts, or cars, can be found frequently in industry sites or usual life. Those cameras show planar motion because the vehicles usually move on a plane. Sometimes the cameras in fork lifts moves vertically. The cameras under planar and vertical motion provides useful properties for horizontal or vertical lines that can be found easily and frequently in our daily life. In this paper, some useful back-projection properties are suggested, which can be applied to horizontal or vertical line images captured by a camera under planar and vertical motion. The line images are back-projected onto a virtual plane that is parallel to the planar motion plane and has the same orientation at the camera coordinate system regardless of camera motion. The back-projected lines on the virtual plane provide useful information for the world lines corresponding to the back-projected lines, such as line direction, angle between two horizontal lines, length ratio of two horizontal lines, and vertical line direction. Through experiments with simple plane polygons, we found that the back-projection properties were useful for estimating correctly the direction and the angle for horizontal and vertical lines.

A Study on the Plane Rectangular Coordinate in Korea (우리나라 평면직각좌표에 관한 연구)

  • 최재화
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.1 no.2
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    • pp.42-59
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    • 1983
  • This article investigates the situation of the Plane Rectangular Coordinate derived from the Gauss Double Projection whereby the positioning of triangulation point in Korea has been represented on. Analyzing and assessing it have been performed by means of new computational method such as computer programing. On the basis of the results brought about, it is found that a new Plane Rectangular Coordinate as well as map projection and scale factor of geodetic length may be adapted to improve the distortion along the geodetic line on a certain zone of map projection in order to enhance the accuracy and the utility of the practical surveying works. The proposals for this study are as follows; (1) projection: Gauss-Kruger's projection (2) Coordinate system: Plane Rectangular coordinate with 8 origin system (3) Scale factor of geodetic length in origin; $m_0=0.9999$

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Realtime Implementation Method for Perspective Distortion Correction (원근 왜곡 보정의 실시간 구현 방법)

  • Lee, Dong-Seok;Kim, Nam-Gyu;Kwon, Soon-Kak
    • Journal of Korea Multimedia Society
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    • v.20 no.4
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    • pp.606-613
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    • 2017
  • When the planar area is captured by the depth camera, the shape of the plane in the captured image has perspective projection distortion according to the position of the camera. We can correct the distorted image by the depth information in the plane in the captured area. Previous depth information based perspective distortion correction methods fail to satisfy the real-time property due to a large amount of computation. In this paper, we propose the method of applying the conversion table selectively by measuring the motion of the plane and performing the correction process by parallel processing for correcting perspective projection distortion. By appling the proposed method, the system for correcting perspective projection distortion correct the distorted image, whose resolution is 640x480, as 22.52ms per frame, so the proposed system satisfies the real-time property.

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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Study on Optimum Design of Steel Plane Frame By Using Gradient Projection Method (Gradient Projection법을 이용한 철골평면구조물의 최적설계연구)

  • LEE HAN-SEON;HONG SUNG-MOK
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1994.04a
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    • pp.38-45
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    • 1994
  • The general conceptual constitution of structural optimization is formulated. The algorithm using the gradient projection method and design sensitivity analysis is discussed. Examples of minimum-weight design for six-story steel plane frame are taken to illustrate the application of this algorithm. The advantages of this algorithm such as marginal cost and design sensitivity analysis as well as system analysis are explained.

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Maximum-Intensity Projection for Magnetic Resonance Angiography (Magnetic Resonance Angiography를 위한 Maximum-Intensity Projection을 구현)

  • Yi, Y.;Ryu, T.H.;Kim, S.S.;Kim, I.Y.;Lee, M.W.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.484-488
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    • 1997
  • In this Paper, We use Maximum-Intensity Projection(MIP) algorithms. Maximum-Intensity Projection algorithms currently used for construction of magnetic resonance angiograms. The blood flow in a volume of interest is represented by bright intensities in the MR data volume. The flow within the vasculature shows up in the projections plane. By relating the intensities of the pixel to their location in the slice, the total number of pixels considered for the projection plane was reduced, thus saving calculation time. The algorithm was written in visual C++.

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A Study on Adjustment of Precision triangulation Network in Korea (우리나라 정밀삼각망조정에 관한 연구)

  • 안철호;유복모;최철순;유환희
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.2 no.2
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    • pp.1-13
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    • 1984
  • Projection has been used in order to indicate the horizontal position of triangulation stations which had been existed on the earth surface. In our country, the plane Rectangular coordinate of the triangulation station is computed by means of Gauss Double projection. But it proves to contain many errors according to the difference in Latitude and longitude. Therefore, in this study Transverse Mercator projection which is known to contain less error than Gauss Double projection in an applied region is introduced, and the results obtain by two these projections and the value today in our country are compared and analysed. when an another plane Rectangular Coordinate system is added to the present 3-plane Rectangular Coordinate system, there is an object inshowing the best position.

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An Efficient 3D Measurement Method that Improves the Fringe Projection Profilometry (Fringe Projection Profilometry를 개선한 효율적인 3D 측정 기법)

  • Kim, Ho-Joong;Cho, Tai-Hoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.10
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    • pp.1973-1979
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    • 2016
  • As technologies evolve, diverse 3D measurement techniques using cameras and pattern projectors have been developed continuously. In 3D measurement, high accuracy, fast speed, and easy implementation are very important factors. Recently, 3D measurement using multi-frequency fringe patterns for absolute phase computation has been widely used in the fringe projection profilometry. This paper proposes an improved method to compute the object's absolute phase using the reference plane's absolute phase and phase difference between the object and the reference plane. This method finds the object's absolute phase by adding the difference between the reference plane's wrapped phase and the object's wrapped phase to the reference plane's absolute phase already obtained in the calibration stage. Through this method, there is no need to obtain multi-frequency fringe patterns about new object for the absolute phase computation. Instead, we only need the object's phase difference relative to the reference planes's phase in the measurement stage.