• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1695-1700
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• 2005

In this paper, 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 surface voxel of photo-consistency with inside voxel on the optic ray of the center camera. As iterating the process of the voxels, the threshold value 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 cut as compare with conventional algorithms.

• Journal of Korean Society on Water Environment
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• v.24 no.6
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• pp.641-650
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• 2008

This paper reviews the infrastructure of the water supply and sewerage system in North Korea. North Korean has similar legal protection to preserve water environment that can be seen in Republic of Korea, but North Korean regulations seemed lack of detailed measures. The critical pollution problems of rivers and lakes in the northern part of peninsula is mainly due to the lack of sewage collection system and poor treatment works. It has been estimated that less than 20% of sewers are connected to the wastewater treatment plants. Although the availability of water resources seemed sufficient, North Koreans suffer the lack of the drinking water supply which needs an urgent attention. Based on the analysis, it has been suggested that the reconstruction of North Korean water and sewage infrastructure needs at least 17.5 trillion Korean Won.

• The Journal of the Korea Contents Association
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• v.13 no.11
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• pp.523-532
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• 2013

Since conventional methods for the reconstruction of 3D objects used a number of cameras or pictures, they required specific hardwares or they were sensitive to the photography environment with a lot of processing time. In this paper, we propose a 3D object reconstruction method using one photograph based on structured light in ubiquitous environments. We use color pattern of the conventional method for structured light. In this paper, we propose a novel pipeline consisting of various image processing techniques for line pattern extraction and matching, which are very important for the performance of the object reconstruction. And we propose the optimal cost function for the pattern matching. Using our method, it is possible to reconstruct a 3D object with efficient computation and easy setting in ubiquitous or mobile environments, for example, a smartphone with a subminiature projector like Galaxy Beam.

• Journal of The Korean Astronomical Society
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• v.47 no.2
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• pp.43-47
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• 2014

Many advanced ground-based solar telescopes improve the spatial resolution of observation images using an adaptive optics (AO) system. As any AO correction remains only partial, it is necessary to use post-processing image reconstruction techniques such as speckle masking or shift-and-add (SAA) to reconstruct a high-spatial-resolution image from atmospherically degraded solar images. In the New Vacuum Solar Telescope (NVST), the spatial resolution in solar images is improved by frame selection and SAA. In order to overcome the burden of massive speckle data processing, we investigate the possibility of using the speckle reconstruction program in a real-time application at the telescope site. The code has been written in the C programming language and optimized for parallel processing in a multi-processor environment. We analyze the scalability of the code to identify possible bottlenecks, and we conclude that the presented code is capable of being run in real-time reconstruction applications at NVST and future large aperture solar telescopes if care is taken that the multi-processor environment has low latencies between the computation nodes.

• Journal of Biomedical Engineering Research
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• v.19 no.2
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• pp.189-198
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• 1998

3D medical image reconstruction techniques are useful to figure out complex 3D structures from the set of 2D sections. In the paper, 3D medical image reconstruction system is constructed under PC environment and programmed based on modular programming by using Visual C++ 4.2. The whole procedures are composed of data preparation, gradient estimation, classification, shading, transformation and ray-casting & compositing. Three speed optimization techniques are used for accelerating 3D medical image reconstruction technique. One is to reduce the rays when cast rays to reconstruct 3D medical image, another is to reduce the voxels to be calculated and the other is to apply early ray termination. To implement 3D medical image reconstruction system based on PC, speed optimization techniques are experimented and applied.

• Korean Journal of Construction Engineering and Management
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• v.23 no.2
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• pp.76-84
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• 2022

Recently, as the frequency of natural disasters has increased, causing enormous human and material damage, the importance of managing disasters is emphasized. In particular, as the concept of Build Back Better becomes meaningful, it has appeared that considering it during Post-disaster Reconstruction is a necessity. Therefore, in this study, the relative importance evaluation and correlation analysis were performed for each influencing factor through the derivation of the influencing factors that should be considered during the reconstruction approach stage of reconstruction after disasters, and a survey of overseas disaster-related experts. As a result of the analysis, 'Adaptability to the environment changes in the future was derived as the most significant influencing factor. It seems that the results of this study can be used as basic data when carrying out the reconstruction project.

• Journal of the Korean housing association
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• v.21 no.6
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• pp.71-80
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• 2010

The purpose of this study is to classify defects of the residential building by analyzing the defect specified by prequalification of residential building reconstruction and to suggest the solution of the problem which can be arisen during each stage of plan, construction and maintenance. By sorting the main defects which is specified by pre-qualification of residential building reconstruction for three years from August 2006 to August 2009 into 4 catagories and analyzing the cause of the defects, we draw the way of maintenance to prevent the defects and make pleasant residential environment. The reason for the frequent defects from residential building is mainly deterioration. It occured on the finishing more than on the structure, which means that residents can find defects easier on the finishing than the structure and clear the demand for repair. The result of analyzing of pre-qualification of residential building reconstruction is that the defects mostly caused small, masonry constructed and lower apartment. The apartment which is not into legal right for maintenance naturally have more defects than the others. In conclusion, it is necessary to establish a law of obligation duty of the maintenance of small apartment.

• Journal of the Korean Society of Costume
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• v.56 no.7 s.107
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• pp.85-100
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• 2006

Fashion related with architectural paradigms includes concept of the space utilization beyond fashions field. Such a fashions concept is able to enlarge as a spatial system like architecture. Interface between fashion and architecture is originated in thinking of the rhizome, which understands fashions field within various relationships between environment of the city and fashion. The existing construction systems of fashion is not sufficient in fashions roles as the space that wearing changing body continuously. Consequently, accommodation of architectural paradigms in fashion depends on new recognition about function and space. Architectural paradigms expressed in fashion since 1990s was classified as follows: 1 modular system of Le Corbusier & Archigram, 2 deconstruction, 3 reconstruction, 4 nomadic architecture. Such a paradigms has been easy to combination among fashion and architecture and furniture. Deconstruction and reconstruction fashion revealed process toward completion, and reappeared architectural consideration about process of change toward incompletion. There are acknowledged formative characteristics as follows: mobility, changeability, multi-function, mutual combinative, openness, and fluidity. This study shows that fashion is essential device determined city environment construction in 21C, and revels that fashion has been highlighted as a presage of new spatial economy received architectural construction systems.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1634-1637
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• 2003

Any given object on the motor-driven turntable is pictured from 8 to 72 different views with a digital camera. 3D shape reconstruction is performed with the integrated software called by Scanware from these multiple digital photographs. There are several steps such as configuration, calibration, capturing, segmentation, shape creation, texturing and merging process during the shape reconstruction process. 3D geometry data can be exported to cad data such as Autocad input file. Also 3D image model is generated from 3D geometry and texture data, and is used to advertise the model in the internet environment. Consumers can see the object realistically from wanted views by rotating or zooming in the internet browsers with Scanbull spx plug-in. The spx format allows a compact saving of 3D objects to handle or download. There are many types of scan equipments such as laser scanners and photogrammetric scanners. Line or point scan methods by laser can generate precise 3D geometry but cannot obtain color textures in general. Reversely, 3D image modeling with photogrammetry can generate not only geometries but also textures from associated polygons. We got various 3D image models and introduced the process of getting 3D image model of an internet-connected watchdog robot.

• Nuclear Engineering and Technology
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• v.56 no.4
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• pp.1153-1164
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• 2024

In recent years, unmanned ground vehicles (UGVs) have been used to search for lost or stolen radioactive sources to avoid radiation exposure for operators. To achieve autonomous localization of radioactive sources, the UGVs must have the ability to automatically determine the next radiation measurement location instead of following a predefined path. Also, the radiation field of radioactive sources has to be reconstructed or inverted utilizing discrete measurements to obtain the radiation intensity distribution in the area of interest. In this study, we propose an effective source localization framework and method, in which UGVs are able to autonomously explore in the radiation area to determine the location of radioactive sources through an iterative process: path planning, radiation field reconstruction and estimation of source location. In the search process, the next radiation measurement point of the UGVs is fully predicted by the design path planning algorithm. After obtaining the measurement points and their radiation measurements, the radiation field of radioactive sources is reconstructed by the Gaussian process regression (GPR) model based on machine learning method. Based on the reconstructed radiation field, the locations of radioactive sources can be determined by the peak analysis method. The proposed method is verified through extensive simulation experiments, and the real source localization experiment on a Cs-137 point source shows that the proposed method can accurately locate the radioactive source with an error of approximately 0.30 m. The experimental results reveal the important practicality of our proposed method for source autonomous localization tasks.