• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.4
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• pp.211-222
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• 2004

Lately construction industry tends to prefer remodeling of existing buildings rather than new construction or reconstruction of buildings due to strengthening of several restriction related to real estates along with prolonged depression. And also, remodeling of building costs less and creates less wastes compared to reconstruction and so it is more profitable in financial and environmental view. However remodeling is process of creating new environment with existing building. Therefor remodeling must follow the procedure realizing problem and fix the problem based on through investigation on existing building and users requirement must be faithfully reflected. Specially in case of apartment houses, since vagueness on ownership and management authority on common parts exists. Hereupon, in this study we are to present the procedure of analyzing apartment house remodeling method through user requirement by approaching to several considerable factors in user request side.

• Journal of Biomedical Engineering Research
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• v.25 no.2
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• pp.97-102
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• 2004

We developed an x-ray cone-beam micro computed tomography (micro-CT) system for small-animal imaging. The micro-CT system consists of a 2-D flat-panel x-ray detector with a field-of-view (FOV) of 120${\times}$120 mm2, a micro-focus x-ray source, a scan controller and a parallel image reconstruction system. Imaging performances of the micro-CT system have been evaluated in terms of contrast and spatial resolution. The minimum resolvable contrast has been found to be less than 36 CT numbers at the dose of 95 mGy and the spatial resolution about 14 lp/mm. As small animal imaging results, we present high resolution 3-D images of rat organs including a femur, a heart and vessels. We expected that the developed micro-CT system can be greatly used in biomedical studies using small animals.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.2
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• pp.108-114
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• 2006

Transient and asymmetric density distributions of butane flow have been investigated from laser image signals by developed three-dimensional digital speckle tomography. Moved signals of speckles have been captured by multiple CCD images in three angles of view simultaneously because the flows were asymmetric and transient. The signals of speckle movements between no flow and downward butane flow from a circular half opening have been calculated by a cross-correlation tracking method so that those distances can be transferred to deflection angles of laser rays fur density gradients. The three-dimensional density fields have been reconstructed from the fringe shift signal which is integrated from the deflection angle by a real-time multiplicative algebraic reconstruction technique (MART).

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.34 no.2
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• pp.121-132
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• 2016

This study proposes an approach for simulating high spatial resolution satellite images acquired under arbitrary sun-sensor geometry using existing images and 3D (three-dimensional) data. First, satellite images, having significant differences in spectral regions compared with those in the simulated image were transformed to the same spectral regions as those in simulated image by using the UPDM (Universal Pattern Decomposition Method). Simultaneously, shadows cast by buildings or high features under the new sun position were modeled. Then, pixels that changed from shadow into non-shadow areas and vice versa were simulated on the basis of existing images. Finally, buildings that were viewed under the new sensor position were modeled on the basis of open library-based 3D reconstruction program. An experiment was conducted to simulate WV-3 (WorldView-3) images acquired under two different sun-sensor geometries based on a Pleiades 1A image, an additional WV-3 image, a Landsat image, and 3D building models. The results show that the shapes of the buildings were modeled effectively, although some problems were noted in the simulation of pixels changing from shadows cast by buildings into non-shadow. Additionally, the mean reflectance of the simulated image was quite similar to that of actual images in vegetation and water areas. However, significant gaps between the mean reflectance of simulated and actual images in soil and road areas were noted, which could be attributed to differences in the moisture content.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.885-890
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• 2008

Until now, the domestic construction market has been formed focusing on new construction and reconstruction in the apartment industry. Recently, however, the remodeling market for old structures have shown a tendency towards land shortage and land price increases in the major cities: the reinforcement of regulations regarding reconstruction; expenditure reduction and the solving of environmental problems by regarding old structures is pursuing low costs and maximum efficiency. The interest in remodeling is increasing, however, remodeling has not been successfully initiated in the apartment division for a reasonable period of time. Consequently to acquire mutual agreement for remodeling from the residential occupants. In order to evaluate profitability, it is necessary to set priorities and reasonable criteria for remodelling and to this end, it is also required to assess each fact of remodelling in view of both customers and supplied. Thus, a sample apartment housing complex was analyzed for geographic location, surrounding environment floor area ratio, site area, number of households, number of stories and unit area and thereupon, its remodelling profitability was analyzed to select an effective remodeling method as an alternative case for apartment house owners and remodelling.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.5
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• pp.35-44
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• 2007

Since the omnidirectional camera system with a very large field of view could take many information about environment scene from few images, various researches for calibration and 3D reconstruction using omnidirectional image have been presented actively. Most of line segments of man-made objects we projected to the contours by using the omnidirectional camera model. Therefore, the corresponding contours among images sequences would be useful for computing the camera transformations including rotation and translation. This paper presents a novel two step minimization method to estimate the extrinsic parameters of the camera from the corresponding contours. In the first step, coarse camera parameters are estimated by minimizing an angular error function between epipolar planes and back-projected vectors from each corresponding point. Then we can compute the final parameters minimizing a distance error of the projected contours and the actual contours. Simulation results on the synthetic and real images demonstrated that our algorithm can achieve precise contour matching and camera motion estimation.

• The KIPS Transactions:PartB
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• v.10B no.5
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• pp.515-520
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• 2003

This paper proposes a calibration method from two images. Camera calibration is necessarily required to obtain 3D Information from 2D images. Previous works to accomplish the camera calibration needed the calibration object or required more than three images to calculate the Kruppa equation, however, we use the geometric constraints of parallelism and orthogonality can be easily presented in man-made scenes. The task of it is to obtain intrinsic and extrinsic camera parameters. The intrinsic parameters are evaluated from vanishing points and then the extrinsic parameters which are consisted of rotation matrix and translation vector of the camera are estimated from corresponding points of two views. From the calibrated parameters, we can recover the projection matrices for each view point. These projection matrices are used to recover 3D information of the scene and can be used to visualize new viewpoints.

• Korean Journal of Construction Engineering and Management
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• v.11 no.1
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• pp.122-129
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• 2010

Until now, the domestic construction market has been formed focusing on new construction and reconstruction in the apartment industry. Recently, however, the remodeling market for old structures have shown a tendency towards land shortage and land price increases in the major cities : the reinforcement of regulations regarding reconstruction ; expenditure reduction and the solving of environmental problems by regarding old structures is pursuing low costs and maximum efficiency. The interest in remodeling is increasing, however, remodeling has not been successfully initiated in the apartment division for a reasonable period of time. Consequently to acquire mutual agreement for remodeling from the residential occupants. In order to evaluate profitability, it is necessary to set priorities and reasonable criteria for remodelling and to this end, it is also required to assess each fact of remodelling in view of both customers and supplied.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.127-135
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• 2015

In this research, we conducted an experiment on evaluating the extending depth information method and surface reconstruction method and the interaction of these two methods in order to enhance the final intermediate view images, which are acquired using DIBR (Depth-Image-Based Rendering) method. We evaluated the experimental control groups using the Microsoft's "Ballet" and "Break Dancer" data sets with three different hole-filling algorithms. The result revealed that the quality was improved the most by applying both extending depth information and surface reconstruction method as compared to the previous point clouds only. In addition, it found that the quality of the intermediate images was improved vastly by only applying extending depth information when using no hole-filling algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.4108-4114
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• 2015

An image acquisition by using an optical mirror is called as a catadioptric method. The catadioptric imaging method is generally used for acquisition of 360-degree all directional visual information in an image. An exemplar omnidirectional optical mirror is the bowl-shaped hyperbolic mirror. In this paper, a single camera omnidirectional stereo imaging method is studied with an additional concave lens. It is possible to obtain 3 dimensional coordinates of environmental objects from the omnidirectional stereo image by matching the stereo image having different view points. The omnidirectional stereo imaging system in this paper is cost-effective and relatively easy for correspondence matching because of consistent camera intrinsic parameters in the stereo image. The parameters of the imaging system are extracted through 3-step calibration and the performance for 3-dimensional coordinates reconstruction is verified through experiments in this paper. Measurable range of the proposed imaging system is also presented by depth-resolution analysis.