• Title/Summary/Keyword: Reconstruct

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Multi-Image Stereo Technique Using Self-Consistency (자기 일치성을 이용한 다중 영상 스테레오 기법)

  • Kim, Min-Suk;Woo, Dong-Min
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.5
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    • pp.226-232
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    • 2001
  • The ability to efficiently and robustly recover accurate 3D terrain models from sets of stereoscopic images is important to many civilian and military applications. To develop an effective and practical terrain modeling system, we propose a new multi-image stereo method which detect unreliable elevations in DEM(Digital Elevation Map), and fuse several DEMs from multiple sources into an accurate and reliable results. This paper focuses on two key factors for generating robust 3D terrain models: the ability to detect unreliable elevation estimates and the ability to fuse the reliable elevations into a single optimal terrain model. We apply the self-consistency methodology to reconstruct accurate DEM from multi-image and show the method is more effective than the conventional stereo image 3D reconstruction method. Using photo-realistic simulator, four synthetic image are generated from ground truth DEM and orthoimage to evaluate the accuracy of the proposed method quantitatively.

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Fabrication of Real-Time Hologram for the Implementation of 3-D Moving Picture (3차원 동영상을 구현하기 위한 실시간 홀로그램의 제작)

  • 박세준;배장근김수중
    • Proceedings of the IEEK Conference
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    • 1998.10a
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    • pp.977-980
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    • 1998
  • A real-time holography system using LCD with CCD camera is proposed. In this system, the rainbow hologram is used since it can be reconstructed by white light source. And to record on CCD camera, a kind of in-line holography method is used to widen the width of the fringe pattern. The interference fringe pattern by proposed system is detected with CCD camera and transferred to the LCD A 3-dimensional image is reconstructed when a white light source illuminates the LCD. So it can represent 3 dimensional moving images at real-time. In this paper, to confirm the usefulness of the proposed method, the reconstructed image by holographic film is compared to the same reconstruct image by LCD. In the recording of the interferenced processing, the optimal ratio of the reference and object beam intenstiy is also investigated.

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Reconstruction of 3-D measurement data

  • Sawada, Hideyiki;Matsumoto-Moriyama, Masao;Fukuda, Hideki;Ishimatsu, Takakazu
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.261-264
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    • 1993
  • To reconstruct the real 3-D shape from the 3-D measurement data from the multiple directions, the rconstruction of the object on the basis of the mosaic processing of the 3-D measurement data are proposed. In this method, to conduct the reconstruction, the connection points have to be identified among the over-lap area between adjacent 3-D data. In this study, the simple image matching method is adopted for the identification of connection points, and this method is verified from numerical experiments.

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Registration multiple range views (복수의 거리영상 간의 변환계수의 추출)

  • 정도현;윤일동;이상욱
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.34S no.2
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    • pp.52-62
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    • 1997
  • To reconstruct the complete 3-D shape of an object, seveal range images form different viewpoints should be merged into a single model. The process of extraction of the transformation parameters between multiple range views is calle dregistration. In this paper, we propose a new algorithm to find the transformation parameters between multiple range views. Th eproposed algorithm consists of two step: initial estimation and iteratively update the transformation. To guess the initial transformation, we modify the principal axes by considering the projection effect, due to the difference fo viewpoints. Then, the following process is iterated: in order to extract the exact transformation parameters between the range views: For every point of the common region, find the nearest point among the neighborhood of the current corresponding point whose correspondency is defined by the reverse calibration of the range finder. Then, update the transformation to satisfy the new correspondencies. In order to evaluate the performance the proposed registration algorithm, some experiments are performed on real range data, acquired by space encoding range finder. The experimental results show that the proposed initial estimation accelerate the following iterative registration step.

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The Clinical Study of Zygomatic Complex Fracture (협골 골절의 임상적 연구)

  • Cho, Byoung-Ouck;Lee, Yong-Chan;Kim, Tae-Young;Koh, Back-Jin
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.11 no.1
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    • pp.63-68
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    • 1989
  • The zygoma is a heavy bone that composes a part of orbit and it was considered to be rarely fractured. However the rate of zygoma injury is increasing due to the outdoor life and motorvehicle accidents. The authors use a bone hook for direct reduction of fractured zygoma in combinaton with a miniplate osteosynthesis for rigid fixation and we reconstruct an infraorbital with a Lyodura.

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An Analysis on the Actual Condition and the Influential Factors in Reconstruction Projects for Deteriorated Apartment Housing (노후아파트의 재건축 추진 영향요인 분석 -대구광역시 사례를 중심으로-)

  • 장석하;현택수;최무현
    • Journal of the Korean housing association
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    • v.10 no.1
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    • pp.145-154
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    • 1999
  • In this study, various factors affect on the reconstruction of the deteriorated apartment housing complex in the Taegu-City were analyzed. The conclusions obtained in this research were summarized as follows; 1) In case of 4 to 5 storied apartment buildings, those were main objects for reconstruction. The number of the buildings and households consisting apartment complex and the total building area and the ground area were appeared as major factors. Those factors were highly correlated with the consensus of reconstruction. 2) As a maximun area of reconstruction was limited, higher existing consensus capacity and its ratio affect negatively on reconstruction of deteriorated apartments. 3) The main motivation for reconstruction is disadvantages among the members of reconstruction association were main obstacles to reconstruct the deteriorated apartment buildings. Therefore, a resoanble alternatives for reconstruction plans and administrative managements were needed.

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Neglected Achilles Tendon Rupture V-Y Tendinous Flap Reconstruction and Isokinetic Plantarflexion Torque Evaluation - Report of 3 Cases - (진구성 아킬레스 건 파열 V-Y 건판 재건술과 등속성 족저 굴곡력 분석 - 3례 보고 -)

  • Jung, Hong-Geun;Kim, Myung-Ho;Kim, Gun-Nam
    • Journal of Korean Foot and Ankle Society
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    • v.4 no.2
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    • pp.87-92
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    • 2000
  • The tendinous ends of neglected achilles tendon rupture tend to retract and separate with atrophy due to gastrosoleus muscle contracture, leaving a wide gap occupied with fibroadipose scar tissue. It is almost impossible to perform simple end-to-end anastomosis after the intervening scar tissue being excised. Therefore many surgical procedures have been proposed to reconstruct the large gap. We treated three such cases by V-Y advancement flap and double Krackow suture technique, and their postoperative strength of triceps surae were evaluated with Cybex isokinetic strength testing. All patients returned to preinjury activities with satisfaction, but the ankle plantar flexor power showed about 20-30% deficit.

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Convolution and Deconvolution Algorithms for Large-Volume Cosmological Surveys

  • Park, KeunWoo;Rossi, Graziano
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.50.4-51
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    • 2015
  • Current and planned deep multicolor wide-area cosmological surveys will map in detail the spatial distribution of galaxies and quasars over unprecedented volumes, and provide a number of objects with photometric redshifts more than an order of magnitude bigger than that of spectroscopic redshifts. Photometric information is statistically more significant for studying cosmological evolution, dark energy, and the expansion history of the universe at a fraction of the cost of a full spectroscopic survey, but intrinsically carries a bias due to noise in the distance estimates. We provide convolution- and deconvolution-based algorithms capable of removing this bias -- thus able to exploit the full cosmological information -- in order to reconstruct intrinsic distributions and correlations between distance-dependent quantities. We then show some direct applications of our techniques to the VIMOS Public Extragalactic Redshift Survey (VIPERS) and the Sloan Digital Sky Survey (SDSS) datasets. Our methods impact a broader range of studies, when at least one distance-dependent quantity is involved; hence, they will be useful for upcoming large-volume surveys, some of which will only have photometric information.

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Reconstruction of Hand Defects with Reverse Posterior Interosseous Artery Flaps (역행성 후 골간 동맥 피판을 이용한 수부결손의 재건)

  • Suh, Young-Suk;Park, Hyung-Taek;Lee, Kun-Sick
    • Archives of Reconstructive Microsurgery
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    • v.10 no.2
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    • pp.149-153
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    • 2001
  • Various types of flaps including local flaps, pedicle flaps and free flap have been used to reconstruct hand soft tissue defects, but each flaps have some limitation and disadvantages. The reverse posterior interosseous artery flap described by Zancolli and Angrigiani have some advantages : preserving the major artery of the hand, minimal donor site morbidity and thin skin. From May 1999 to May 2001, we reconstructed 18 cases of hand defects in industrial injury with reverse posterior interosseous artery flaps and partial distal part necrosis of flaps due to infection developed in a case but other 17 cases survived completely without any specific complication.

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Elementary Teachers' Use of Mathematical Textbooks in Korea

  • Lee, Kwang-Ho;Ha, Su-Hyun
    • Research in Mathematical Education
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    • v.15 no.3
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    • pp.261-294
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    • 2011
  • The purpose of this research is to analyze Korean teacher textbook use and explore the effective use of textbooks. The researcher surveyed teachers to obtain information relative to their dispositions and views of textbook use, and a subset interviewed to obtain additional insight about these views. For the sample, 278 elementary school teachers were surveyed and a group interview was conducted with 6 teachers. The results showed that many teachers teach all the students simply by following the textbook content. These results suggest that for effective us of textbooks, teachers need to understand how to reconstruct the textbook within an understanding of the textbook authors' intension for the textbook content.