• Title/Summary/Keyword: Real time reconstruction

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Analysis and Reconstruction of Vehicle Speeds to Design an Efficient Time Dependent VRP Heuristic (시간종속VRP의 효율적 해법 설계를 위한 차량통행속도의 분석과 재구성)

  • Moon, Gee-Ju;Park, Sung-Mee
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.35 no.1
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    • pp.140-147
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    • 2012
  • Vehicle routing problem is one of the traveling salesman problems with various conditions such as vehicle capacity limits, delivery time windows, as well as time dependent speeds in metropolitan area. In this research hourly vehicle moving speeds information in a typical metropolitan area are analyzed to use the results in the design procedure of VRP heuristic. Quality initial vehicle routing solutions can be obtained with adaption of the analysed results of the time periods with no vehicle speed changes. This strategy makes complicated time dependent vehicle speed simple to solve. Time dependent vehicle speeds are too important to ignore to obtain optimum vehicle routing search for real life logistics systems.

Implementation of Optimized 3D Input & Output Systems for Web-based Real-time 3D Video Communication (웹 기반의 입체 동영상 통신을 위한 3차원 입출력 시스템의 최적화 구현)

  • Ko, Jung-Hwan;Lee, Jung-Suk;An, Young-Hwan
    • 전자공학회논문지 IE
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    • v.43 no.4
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    • pp.105-114
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    • 2006
  • In this paper, 3D input and output systems for a web-based real-time 3D video communication system using IEEE 1394 digital cameras, Intel Xeon Server system and Microsoft Directshow library is proposed. And some conditions for optimizing the operations of the stereo camera, 3D display and signal processing system are analyzed. Input & output systems are carefully selected, which can satisfy the required optimization conditions and the final 3D video communication system is implemented by using three optimized devices. The overall control system is developed with Microsoft Visual C++.Net and Microsoft DirectX 9.1 SDK. Some experimental results show that the observer can feel the natural presence from multi-view(4-view) 3D video of server system in real-time and also can feel the natural presence from 3D video of client system and finally suggest an application possibility of the proposed web-based real-time 3D video communication in real fields.

ROV Control System Real-time Component Design for Reconstruction (무인 수중 건설 로봇 재구성을 위한 관제 시스템 실시간 컴포넌트 설계)

  • Kim, Chang-Deok;Yun, Cheong
    • Proceedings of the Korea Information Processing Society Conference
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    • 2017.04a
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    • pp.685-687
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    • 2017
  • 최근 공중, 지상에 대해 무인 시스템이 빠른 속도로 발전하고 있다. 해양 분야에 대해서도 무인시스템이 발전함으로 인해 사람의 힘을 빌려 작업하기에는 많은 위험도와 각종 변수들에 의해 인명피해가 발생할 수 있는 건설, 케이블 매설, 해양 관측에 대해 무인 로봇을 통해 작업이 이루어지고 있다. 이러한 무인 시스템의 발전을 하드웨어는 빠르게 발전하여 컴포넌트 형태로 발전하였다. 이런 하드웨어의 발전에 맞춰 소프트웨어 컴포넌트 설계 방법을 제안하고자 한다.

Optical Scanning Holographic Approach to Three-Dimensional Television

  • Poon, Ting-Chung
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.281-284
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    • 2002
  • We first review a real-time holographic recording technique called optical scanning holography (OSH) and discuss holographic reconstruction using spatial light modulators (SLMs). We then present how the overall system can be used for three-dimensional (3-D) holographic television (TV) system and address some of the issues encountered. Finally, we suggest some techniques to alleviate the issues encountered in such a 3-D holographic TV.

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A New Shack-Hartmann Type Wavefront Sensor Using Liquid Crystal Panels

  • Xiaoxi, Chen;Xu, Liu
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.528-530
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    • 2005
  • In this paper, we present a new and practical method for achieving real-time wavefront measurement, dramatically increasing the resolution, dynamic range of Shack-Hartmann wavefront sensor and improving the wavefront reconstruction quality. In proposal method, a liquid crystal display panel (LCD) for the generation of an array of Fresnel microlenses is use instead of the static microlens array of the conventional Shack-Hartmann type sensor. An off-axis holographic microlens array is designed instead of the normal microlens array to increase the effective array and then the dynamic range. The focus properties of the off-axis lens are studied.

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Three-Dimensional Television using Optical Scanning Holography

  • Poon, Ting-Chung
    • Journal of Information Display
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    • v.3 no.3
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    • pp.12-16
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    • 2002
  • We first review a real-time three-dimensional (3-D) holographic recording technique called optical scanning holography (OSH) and discuss holographic reconstruction using spatial light modulators (SLMs). We then present how the overall system can be used for 3-D holographic television (TV) display with a wide-angle view of a 3-D image, and address some of the issues encountered. Finally, we suggest some techniques to alleviate the issues encountered in such a 3-D holographic TV system.

A 3D Face Reconstruction Method Robust to Errors of Automatic Facial Feature Point Extraction (얼굴 특징점 자동 추출 오류에 강인한 3차원 얼굴 복원 방법)

  • Lee, Youn-Joo;Lee, Sung-Joo;Park, Kang-Ryoung;Kim, Jai-Hie
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.48 no.1
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    • pp.122-131
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    • 2011
  • A widely used single image-based 3D face reconstruction method, 3D morphable shape model, reconstructs an accurate 3D facial shape when 2D facial feature points are correctly extracted from an input face image. However, in the case that a user's cooperation is not available such as a real-time 3D face reconstruction system, this method can be vulnerable to the errors of automatic facial feature point extraction. In order to solve this problem, we automatically classify extracted facial feature points into two groups, erroneous and correct ones, and then reconstruct a 3D facial shape by using only the correctly extracted facial feature points. The experimental results showed that the 3D reconstruction performance of the proposed method was remarkably improved compared to that of the previous method which does not consider the errors of automatic facial feature point extraction.

Effect of Dimension Reduction on Prediction Performance of Multivariate Nonlinear Time Series

  • Jeong, Jun-Yong;Kim, Jun-Seong;Jun, Chi-Hyuck
    • Industrial Engineering and Management Systems
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    • v.14 no.3
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    • pp.312-317
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    • 2015
  • The dynamic system approach in time series has been used in many real problems. Based on Taken's embedding theorem, we can build the predictive function where input is the time delay coordinates vector which consists of the lagged values of the observed series and output is the future values of the observed series. Although the time delay coordinates vector from multivariate time series brings more information than the one from univariate time series, it can exhibit statistical redundancy which disturbs the performance of the prediction function. We apply dimension reduction techniques to solve this problem and analyze the effect of this approach for prediction. Our experiment uses delayed Lorenz series; least squares support vector regression approximates the predictive function. The result shows that linearly preserving projection improves the prediction performance.

Real-time Data Enhancement of 3D Underwater Terrain Map Using Nonlinear Interpolation on Image Sonar (비선형 보간법을 이용한 수중 이미지 소나의 3 차원 해저지형 실시간 생성기법)

  • Ingyu Lee;Jason Kim;Sehwan Rho;Kee–Cheol Shin;Jaejun Lee;Son-Cheol Yu
    • Journal of Sensor Science and Technology
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    • v.32 no.2
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    • pp.110-117
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    • 2023
  • Reconstructing underwater geometry in real time with forward-looking sonar is critical for applications such as localization, mapping, and path planning. Geometrical data must be repeatedly calculated and overwritten in real time because the reliability of the acoustic data is affected by various factors. Moreover, scattering of signal data during the coordinate conversion process may lead to geometrical errors, which lowers the accuracy of the information obtained by the sensor system. In this study, we propose a three-step data processing method with low computational cost for real-time operation. First, the number of data points to be interpolated is determined with respect to the distance between each point and the size of the data grid in a Cartesian coordinate system. Then, the data are processed with a nonlinear interpolation so that they exhibit linear properties in the coordinate system. Finally, the data are transformed based on variations in the position and orientation of the sonar over time. The results of an evaluation of our proposed approach in a simulation show that the nonlinear interpolation operation constructed a continuous underwater geometry dataset with low geometrical error.