• Title/Summary/Keyword: View Points

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Multi-view Display with Hologram Screen using Three-dimensional Bragg Diffraction

  • Okamoto, Masaaki;Shimizu, Eiji
    • Journal of Information Display
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    • v.3 no.3
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    • pp.1-11
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    • 2002
  • Multi-view function is important to three-dimensional displays without dedicated glasses. It is the reason that the observers earnestly desire to change their positions freely. Multi-viewing is also principal to the reality of three-dimensional (3D) image displayed on the screen. The display of projection type has the advantage that the number of viewing points can be easily increased according to the number of projectors. The authors research on multi-view projection display with hologram screen. Powerful directionality of the diffracted beam from hologram screen is required unlike two-dimensional (2D) display. We developed a new method that all diffracted beams satisfied the same Bragg condition and became sufficiently bright to observe the 3D image under usual indoor light. The principle is based on the essential Bragg diffraction in the three-dimensional space. Owing to such three-dimensional Bragg diffraction we achieved an excellent hologram screen that could be multiple reconstructed in spite of single recording. This hologram screen is able to answer arbitrary numbers of viewing points within wide viewing zone. The distortion of 3D image becomes also sufficiently small with the method of dividing the cross angle between illumination and diffraction beam.

Navigation Sign Recognition in Indoor enviroments Using Fuzzy Inference (퍼지추론을 이용한 실내환경에서의 주행신호인식)

  • 김전호;유범재;조영조;박민용;고범석
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1997.11a
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    • pp.141-144
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    • 1997
  • This paper presents a method of navigation sign recognition in indoor environments using a fuzzy inference for an autonomous mobile robot. In order to adapt to image deformation of a navigation sign resulted from variations of view-points and distances, a multi-labeled template matching(MLTM) method and a dynamic area search method(DASM) are proposed. The DASM is proposed to detect correct feature points among incorrect feature points. Finally sugeno-style fuzzy inference are adopted for recognizing the navigation sign.

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Evaluation of the possibility of clinical application by surface dose measurement of ViewRay in MFW treatment (MFW 치료 시 ViewRay의 표면선량 측정에 따른 임상 적용 가능성 평가)

  • Sun, Geo Jun;Son, Sang Jun;Lee, Yang Hoon;Lee, Je Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.30 no.1_2
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    • pp.169-176
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    • 2018
  • Purpose : The purpose of this study is to evaluate clinical applicability of Co-60 ViewRay treatment plan to increase the skin dose in case of high skin dose is required such as Malignant Fungating Wound By measuring the presence / absence of Bolus application and skin dose by the treatment device and comparing it Materials and Methods : Nine inner measuring points of 2.5 cm lattice arrangement and all 13 measuring points including upper and lower left and right measuring points touching the chest and skin were marked. After CT was taken, each treatment plan was formulated through Eclipse and ViewRay-TPS, and a Fixed beam-IMRT treatment plan was formulated so that the left chest V2Gy=95 % is delivered. Before measurement QED detector was calibrated and the QED detector was positioned at the 13 measurement points displayed on Phantom and surface dose of each treatment planner was measured using 5 mm Bolus application using True-beam and View-ray before and after, measure three times and compare each before applying 5 mm Bolus. Results : The surface dose of the Co-60 ViewRay and the linear accelerator appeared at $76.8%{\pm}5.2%$ vs. $67.3{\pm}%7.5%$ and the surface dose after application of 5 mm Bolus was $87.6%{\pm}8.9%$ vs. $80.3%{\pm}10.2%$ It was measured at 10.2 % (p<0.001). Conclusion : As a result of the surface dose measurement of each treatment instrument, Co-60 ViewRay confirmed that the surface dose reached 95.6 % of 6 MV Linac with conventional 5 mm bolus, despite not using Bolus (p<0.001). Also, by utilizing magnetic resonance images for each treatment, it is possible to observe the change in the treatment site without the problem of exposure, it is easy to formulate an adaptive treatment plan and it is easy to secure the skin dose, so the size In the case of Malignant Fungating Wound patients who need fast skin changes and need high skin doses, Co-60 ViewRay is considered to be more useful than linear accelerators.

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Perspectives of Game in Terms of Interactivity between Game Texts and Players (게임 텍스트와 플레이어의 인터랙티브적 관점에서 본 게임의 시점)

  • Kihl, Tae-Suk;Chang, Jun-O
    • Journal of Korea Game Society
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    • v.8 no.3
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    • pp.51-59
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    • 2008
  • This article focuses on perspectives of game in terms of interactivity between game texts and players. There are many points of view which have been discussed, such as first person point of view, third person point of view, top-down point of view, side-view point of view, quarter-view point of view, and isometric point of view, but they are too insufficient to fully explain the perspectives of game from the viewpoint of the interactivity. This paper examines the function of player and game manufacturer as implied authors on interactive point of view, and discusses the perspectives of game through a sense of distance between players as implied author and player characters.

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Dynamic Stitching Algorithm for 4-channel Surround View System using SIFT Features (SIFT 특징점을 이용한 4채널 서라운드 시스템의 동적 영상 정합 알고리즘)

  • Joongjin Kook;Daewoong Kang
    • Journal of the Semiconductor & Display Technology
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    • v.23 no.1
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    • pp.56-60
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    • 2024
  • In this paper, we propose a SIFT feature-based dynamic stitching algorithm for image calibration and correction of a 360-degree surround view system. The existing surround view system requires a lot of processing time and money because in the process of image calibration and correction. The traditional marker patterns are placed around the vehicle and correction is performed manually. Therefore, in this study, images captured with four fisheye cameras mounted on the surround view system were distorted and then matched with the same feature points in adjacent images through SIFT-based feature point extraction to enable image stitching without a fixed marker pattern.

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A Weighted Points Registration Method to Analyze Dimensional Errors Occurring during Shipbuilding Process (선박 건조 과정에서 발생하는 치수 오차 분석을 위한 가중 포인트 정합 방법)

  • Kwon, Kiyoun
    • Korean Journal of Computational Design and Engineering
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    • v.21 no.2
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    • pp.151-158
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    • 2016
  • It is important to analyze dimensional errors occurring during shipbuilding process. A ship is constructed by assembling blocks and installing outfits in assembled ship structure. Blocks and outfits have a main direction that has greater importance than other directions from the view point of dimensional error. Therefore, a main direction should have a greater weighting factor than other directions in order to achieve meaningful inspection results. In this paper, a modified point registration method based on iterative closest point (ICP) is proposed. In this method, a user determines one or two main directions among x, y, and z directions, and then each main direction is made to have a greater weighting factor than other directions. For points registration, mapping between measured points and design points are performed by the modified ICP in which weighting factor assigned to each main direction is considered.

High accuracy online 3D-reconstruction by multiple cameras

  • Oota, Yoshikazu;Pan, Yaodong;Furuta, Katuhisa
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1749-1752
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    • 2005
  • For online high accurate reconstruction of an object from an visual information, a linear reconstruction method for multiple images is popular. Basically this method needs many cameras or many different screen shots from different view points. This method, however, has the benefit of less calculation and is adequate for a real time application by comparing other popular method. In this paper, online reconstruction system using more than three cameras is treated. An evaluation method of cameras' position, and of the number is derived for the linear reconstruction method. To decrease errors that are caused from skew of lens, positional error between corresponding points is taken into consideration on the evaluation. The proposed evaluation method enables estimation of the adequate number of cameras and then of feasible view locations. Additionally, repeating search of epipolar lines enables estimation of the hidden point. Comparing with result of an average error analysis, it was confirmed that the proposed methods works effectively.

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