• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4152-4158
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• 2012

The Stereo X-ray inspection system is designed for effectively providing the additional information of objects than the conventional inspection system that offers only 2D cross-section of objects. We studied the geometric improvement of the stereo X-ray inspection system, the stereo matching algorithm of the single object using the edge and the volume reconstruction method for the inspected object. In this paper, we conduct a matching algorithm to find the correspondences between the images and reconstruct 3-D shapes of real objects using the stereo X-ray images. Also, we apply a new 3D reconstruction algorithm for the discrimination of two objects. For the separation of the overlapping objects, we calculate the vector of the object and divide inner and outer voxel of objects. And for the elimination of the overlapping area, we study the reconstruct 3D shapes using the threshold based Z-axis. The experimental results show that the proposed technique can enhance the accuracy of stereo matching and give more efficient visualization for overlap objects in the restricted environment.

• Journal of Korean Society of Transportation
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• v.20 no.3
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• pp.105-113
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• 2002

As the number of pedestrian accident increases, the reconstruction of an accident becomes important to find the source of the fault. Generally, accidents are reconstructed by the intuition of experts or primitive physics. A reconstruction method is proposed using sophisticated optimization technology. At first, a dynamic simulation model is established for the accident environment. Occupant analysis for automobile crashworthiness is employed. The situation before an accident is identified by optimization. The impact velocity and the position of the pedestrian are utilized as design variables. The design variables are found by minimizing the difference between the simulation and the real accident. The optimization process is performed by linking an occupant analysis program MADYMO to an optimization program VisualDOC. Since the involved analysis is dynamics and highly nonlinear, response surface method is selected for the optimization process. Problems are solved for various situations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.5
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• pp.951-958
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• 2017

In an attack context, the adversary wants to retrieve the message from the intercepted noisy bit stream without any prior knowledge of the channel codes used. The process of finding out the code parameters such as code length, dimension, and generator, for this purpose, is called the blind recognition of channel codes or the reconstruction of channel codes. In this paper, we suggest an improved algorithm of the blind recovery of rate k/n convolutional encoders in a noisy environment. The suggested algorithm improves the existing algorithm by Marazin, et. al. by evaluating the threshold value through the estimation of the channel error probability of the BSC. By applying the soft decision method by Shaojing, et. al., we considerably enhance the success rate of the channel reconstruction.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.1
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• pp.13-22
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• 2009

In this paper, we propose the 3D shape reconstruction method that combine the mosaic method and the active stereo matching using the laser beam. The active stereo matching method detects the position information of the irradiated laser beam on object by analyzing the color and brightness variation of left and right image, and acquires the depth information in epipolar line. The mosaic method extracts feature point of image by using harris comer detection and matches the same keypoint between the sequence of images using the keypoint descriptor index method and infers correlation between the sequence of images. The depth information of the sequence image was calculated by the active stereo matching and the mosaic method. The merged depth information was reconstructed to the 3D shape information by wrapping and blending with image color and texture. The proposed reconstruction method could acquire strong the 3D distance information, and overcome constraint of place and distance etc, by using laser slit beam and stereo camera.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.42 no.6
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• pp.93-100
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• 2005

We propose an optimal thresholding method for the voxel coloring in the reconstruction of a 3D shape. Our purposed method is a new approach to resolve the trade-off error of the threshold value on determining the photo-consistency in the conventional method. Optimal thresholding value is decided to compare the photo-consistency of a surface with inside voxel on the optic ray of the center camera. As iterating the process of the vokels, the threshold is approached to the optimal value for the individual surface voxel. And also, graph cut method is reduced to the surface noise on eliminating neighboring voxel. To verify the proposed algorithm, we simulated in the virtual and real environment. It is advantaged to speed up and accuracy of a 3D face reconstruction by applying the methods of optimal threshold and graph as compare with conventional algorithms.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.695-698
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• 2014

As most the scanning systems developed until now provide radiation scan plane images of the inspected objects, there has been a limitation in judging exactly the shape of the objects inside a logistics container exactly with only 2-D radiation image information. Two 2-dimensional radiation images which have different disparity values are acquired from a newly designed stereo image acquisition system which has one additional line sensor to the conventional system. Using a matching algorithm the 3D reconstruction process which find the correspondence between the images is progressed. In this paper, we proposed a new volume based 3D reconstruction algorithm and experimental results show the proposed new volume based reconstruction technique can provide more efficient visualization for cargo inspection. The proposed technique can be used for the development of the high speed and more efficient non-destructive auto inspection system.

• Journal of the Society of Naval Architects of Korea
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• v.61 no.3
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• pp.143-151
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• 2024

In this study, we present a mapping framework for 3D spatial reconstruction of digital twin model using navigation and perception sensors mounted on an Autonomous Surface Vehicle (ASV). For improving the level of realism of digital twin models, 3D spatial information should be reconstructed as a digitalized spatial model and integrated with the components and system models of the ASV. In particular, for the 3D spatial reconstruction, color and 3D point cloud data which acquired from a camera and a LiDAR sensors corresponding to the navigation information at the specific time are required to map without minimizing the noise. To ensure clear and accurate reconstruction of the acquired data in the proposed mapping framework, a image preprocessing was designed to enhance the brightness of low-light images, and a preprocessing for 3D point cloud data was included to filter out unnecessary data. Subsequently, a point matching process between consecutive 3D point cloud data was conducted using the Generalized Iterative Closest Point (G-ICP) approach, and the color information was mapped with the matched 3D point cloud data. The feasibility of the proposed mapping framework was validated through a field data set acquired from field experiments in a inland water environment, and its results were described.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.639-644
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• 2003

An unstructured environment requires a robot to possess outstanding mobility and advanced control algorithms since there exist complicated configurations such as obstacle, uneven surface, etc. Especially, when a quadruped robot walks in these environments, obstacles in the walking route will obstruct the walking or may give rise to a serious trouble. In this paper, we introduce a strategy for the stable walking in unstructured environment. The proposed strategy consists of two control algorithms. One is a collision{free algorithm to avoid obstacles and the other is an algorithm to overcome any obstacle. These are based on the obstacle detection method and a shape reconstruction algorithm, Which algorithms are described in detail. In addition, the validity of these algorithms have been demonstrated through experiments using a quadruped walking robot called "MRWALLSPECT III(Multifunctional Robot for Wall inSPECTion version 3 )".

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.4
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• pp.21-28
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• 2012

Hoe beak village (Donggu manseokdong, Akasaki Village) is the oldest slums in Incheon. Recently, 'Mixed residential environment improvement project' is being promoted as Aboriginal entire resettlement goals in place of 'new building reconstruction and redevelopment projects' knock down everything this hoe beak village existed already. Resident representatives meeting configuration goes, but still do business magazine in the right direction. Therefore, in this study, the proposed architectural solutions to meet the demand of residents on the research problems, performed in a manner that the local improved hoe Buri village residential environment improvement projects and analyze the current situation and characteristics. In this study, the following improvements are presented. Prepare guidelines and maintain design guidelines for maintaining the identity of the village, Improve continuous landscape of the village, Construction of mixed-use sanitation facilities, Using a mini-lot and Vacant for Ssamzie Park Development, Units of housing types for Shared housing and co-operation are proposed.

• Journal of Digital Contents Society
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• v.8 no.3
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• pp.365-370
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• 2007

This paper proposes a new algorithm that generates a panorama image for reconstruction of image-based virtual environment. Proposed algorithm can generate panorama image from input images using the projective transform based on the feature model and a fully immersive image-based virtual environment according to the user's view point by the sphere mapping. Especially, proposed algorithm supports robust methods of camera rotation and is applied to various images to estimate ist performance.