• Title/Summary/Keyword: Reconstruct

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Reconstruction of polygonal prisms from point-clouds of engineering facilities

  • Chida, Akisato;Masuda, Hiroshi
    • Journal of Computational Design and Engineering
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    • v.3 no.4
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    • pp.322-329
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    • 2016
  • The advent of high-performance terrestrial laser scanners has made it possible to capture dense point-clouds of engineering facilities. 3D shape acquisition from engineering facilities is useful for supporting maintenance and repair tasks. In this paper, we discuss methods to reconstruct box shapes and polygonal prisms from large-scale point-clouds. Since many faces may be partly occluded by other objects in engineering plants, we estimate possible box shapes and polygonal prisms and verify their compatibility with measured point-clouds. We evaluate our method using actual point-clouds of engineering plants.

Improved Compressed Network Coding Scheme for Energy-Efficient Data Communication in Wireless Sensor Networks

  • Zhou, Ying;Yang, Lihua;Yang, Longxiang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.6
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    • pp.2946-2962
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    • 2017
  • An improved energy-efficient compressed network coding method is proposed for the data communication in the wireless sensor networks (WSNs). In the method, the compressed sensing and network coding are jointly used to improve the energy efficiency, and the two-hop neighbor information is employed to choose the next hop to further reduce the number of the transmissions. Moreover, a new packet format is designed to facilitate the intermediate node selection. To theoretically verify the efficiency of the proposed method, the expressions for the number of the transmissions and receptions are derived. Simulation results show that, the proposed method has higher energy efficiency compared with the available schemes, and it only requires a few packets to reconstruct measurements with reasonable quality.

Cranially-based nasolabial flaps for the reconstruction of nasal surgical defects

  • Kerem, Hakan;Bali, Ulas;Sonmez, Erhan;Evrenos, Mustafa Kursat
    • Archives of Plastic Surgery
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    • v.45 no.2
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    • pp.140-145
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    • 2018
  • Background Cranially-based nasolabial flaps are a good alternative for the reconstruction of nasal defects. Methods A cranially-based nasolabial flap was used in 18 patients to reconstruct defects of the nose from 2010 to 2016, and the long-term results are presented in this report. Results Fifteen of the flaps completely survived. All the patients had a bulky appearance, but they did not want to undergo a second operation for cosmesis. The dissection of the flap took approximately 20 minutes, and the total operation lasted for 1 hour. The patients were hospitalized for 1-7 days, and the postoperative follow-up period was 1-28 months (mean, 17 months). Conclusions The cranially-based nasolabial flap possesses all the advantages of the traditional forehead flap, and can safely be used in selected cases.

A Camera Pose Estimation Method for Rectangle Feature based Visual SLAM (사각형 특징 기반 Visual SLAM을 위한 자세 추정 방법)

  • Lee, Jae-Min;Kim, Gon-Woo
    • The Journal of Korea Robotics Society
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    • v.11 no.1
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    • pp.33-40
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    • 2016
  • In this paper, we propose a method for estimating the pose of the camera using a rectangle feature utilized for the visual SLAM. A warped rectangle feature as a quadrilateral in the image by the perspective transformation is reconstructed by the Coupled Line Camera algorithm. In order to fully reconstruct a rectangle in the real world coordinate, the distance between the features and the camera is needed. The distance in the real world coordinate can be measured by using a stereo camera. Using properties of the line camera, the physical size of the rectangle feature can be induced from the distance. The correspondence between the quadrilateral in the image and the rectangle in the real world coordinate can restore the relative pose between the camera and the feature through obtaining the homography. In order to evaluate the performance, we analyzed the result of proposed method with its reference pose in Gazebo robot simulator.

Organization of Government in Metropolitan Areas -A Problem of Theoretical Conflation- (광역도시지역의 정부형태 -이론융합의 문제-)

  • Choi, Jeong-Youl
    • Proceedings of the Korea Contents Association Conference
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    • 2006.11a
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    • pp.369-371
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    • 2006
  • Reform vs. Public Choice framework has long been a primary pattern for the debate on Organization of Government in Metropolitan Areas (OGMA). As one of the significant theoretical issues in contemporary Public Administration, the framework has reached at the state of intellectual impasse in that there seemed no decisive winner between the two camps[1]. In order to break this unentertaining balance, the article tries to reconstruct a theoretical conflation, a conceptual logic embedded in the conventional dichotomy. Moreover the result can help us start to imagine a system-like functioning of polycentric arrangement of local polities within a metropolitan region.

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Towards the Reconstruction of Time-dependent Vibronic States from Nonlinear Wavepacket Interferometry Signals

  • Humble, Travis S.;Cina, Jeffrey A.
    • Bulletin of the Korean Chemical Society
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    • v.24 no.8
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    • pp.1111-1118
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    • 2003
  • We present one-color nonlinear wavepacket interferometry (WPI) signal calculations for a system of two electronic levels and one vibrational degree of freedom. We consider two cases, a displaced harmonic oscillator system, which can be treated analytically, and a model photodissociative system, whose WPI signal must be calculated by numerical wavepacket propagation. We show how signals obtained with different combinations of intrapulse-pair phase shifts can be combined to isolate the complex-valued overlap between a given onepulse target wavepacket and a variable three-pulse reference wavepacket. We demonstrate that with a range of inter- and intrapulse-pair delays the complex overlaps and variable reference states can be used to reconstruct the target wavepacket. We compare our results with previous methods for vibronic state reconstruction based on linear WPI and discuss further generalizations of our method.

Inverse Scattering Method Using the Moment Method in the Angular Spectral Domain (각스펙트럼 영역에서 모멘트 방법을 이용한 역산란 방법)

  • 이경수;김세윤;나정웅
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.3 no.2
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    • pp.46-55
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    • 1992
  • In this paper, A spectral inversion scheme in cylinderical coordinates, appling the moment method procedure is suggested to reconstruct permittivity profiles of inhomogeneous dielectric objects. Angular spectral domain reconstruction is shown to be less sensitive to the ill-posedness due to the noise in the scattered field then the configuration reconstruction

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Collision Configurations Reconstruction Using Deformation Shape and Deformation Severity of Car Body (차체의 변형상과 변형정도에 의한 자동차 충돌상황의 재구성)

  • 장인식;채덕병
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.1
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    • pp.171-180
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    • 2001
  • Collision accident reconstruction algorithm are developed based on the deformation shape and severity of a car body. At first, the body stiffness equation representing the force-deformation relationship is derived using finite element analysis for head on collision of two cars. The database of deformation shapes and energies is constructed for five different collision configurations; each configuration contains three velocity conditions. Deformation shapes are obtained using a curve fitting method and result in cubic polynomials. Deformation energies are calculated using a stiffness equation and deformation data. Three algorithms are developed to reconstruct collision configuration compared with constructed database. The developed algorithms show reasonably good performance to find collisions conditions for some test problems.

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Shape Recognition of 3-D Object Using Texels (텍셀을 이용한 3차원 물체의 형상 인식)

  • Kim, Do-Nyun;Cho, Dong-Sub
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.460-464
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    • 1990
  • Texture provides an important source of information about the local orientation of visible surfaces. An important task that arises in many computer vision systems is the reconstruction of three-dimensional depth information from two-dimensional images. The surface orientation of texel is classified by the Artificial Neural Network. The classification method to recognize the shape of 3D object with artificial neural network requires less developing time comparing to conventional method. The segmentation problem is assumed to be solved. The surface in view is smooth and is covered with repeated texture elements. In this study, 3D shape reconstruct using interpolation method.

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Noise Attenuation of Marine Seismic Data with a 2-D Wavelet Transform (2-D 웨이브릿 변환을 이용한 해양 탄성파탐사 자료의 잡음 감쇠)

  • Kim, Jin-Hoo;Kim, Sung-Bo;Kim, Hyun-Do;Kim, Chan-Soo
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.8
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    • pp.1309-1314
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    • 2008
  • Seismic data is often contaminated with high-energy, spatially aliased noise, which has proven impractical to attenuate using Fourier techniques. Wavelet filtering, however, has proven capable of attacking several types of localized noise simultaneously regardless of their frequencies. In this study a 2-D stationary wavelet transform is used to decompose seismic data into its wavelet components. A threshold is applied to these coefficients to attenuate high amplitude noise, followed by an inverse transform to reconstruct the seismic trace. The stationary wavelet transform minimizes the phase-shift errors induced by thresholding that occur when the conventional discrete wavelet transform is used.