• 한국지구물리탐사학회:학술대회논문집
• /
• 2005.05a
• /
• pp.281-286
• /
• 2005

This paper presents sensitivity analysis of generalized rapid relaxation inversion (GRRI) algorithm for inverting controlled-source audio-frequency magnetotelluric (CSAMT) data. The algorithm was originally developed by modifying the RRI algorithm to recover a two-dimensional (2-D) conductivity structure of the Earth from MT data, but can be extended to include CSAMT data if it is combined with 2.5-D forward modeling. These GRRI approximate sensitivities are validated by comparison with exact 1-D and 2.5-D sensitivities. The comparison shows that the GRRI sensitivity is a good approximation to the exact sensitivity and has about half magnitude of the RRI sensitivity. Although the magnitude of the GRRI sensitivity is still slightly larger than that of the 2.5-D sensitivity, both sensitivities are broadly similar in shape when source-receiver offsets are greater than one skin depth on the Earth.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.30 no.1
• /
• pp.31-37
• /
• 2017

In this paper, computation results of reducible modeling, stress recovery and energy release rate were compared with the results of VABS, Virtual Crack Closure Technique. The result of stress recovery analysis for 1-D model including the stiffness matrix is compared with stress results of three-dimensional 3-D FEM. Energy release rate of composite beam with longitudinal cracks is calculated and compare verifications of numerical analysis results of 3-D FEM and VABS. The procedure of calculating energy release rate through dimensional reduction and stress recovery is intended to be efficient and be utilized in the life-cycle of high-altitude uav's wing, wind blades and tilt rotor blade.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.22 no.11
• /
• pp.1505-1510
• /
• 2018

Product modeling technology for graphics is rapidly developing. And 3D data application and usability are increasing.modeling of product design is a very important factor in constructing. 3D modeling in product design takes a lot of production time. Recently, the reverse design method is very useful because of application of 3D data and shortening of production time. In this study, first, 3D point cloud and mesh data are generated using photographs based on image data. The second is to modify the design and the third is to make the prototype with the 3D printer. This product design and production process suggests the utilization and possibility of image data, the shortening of 3D modeling production time and efficient processes. Also, the product design process proposes a model of a new product development system to adapt to the production environment.

• Composites Research
• /
• v.29 no.1
• /
• pp.16-23
• /
• 2016

In this paper, numerical results of sectional analysis, stress recovery and energy release rate were compared with the results of VABS, 3-D FEM through the blade analysis library. The result of stress recovery analysis for one-dimensional model including the stiffness matrix is compared with stress results of three-dimensional FEM. We discuss the configuration of the blade analysis library and compare verifications of numerical analysis results of VABS. Blade analysis library through dimensional reduction and stress recovery is intended to be utilized in conjunction with pre- and post-processing of the analysis program of the composite blade, high-altitude uav's wing, wind blades and tilt rotor blade.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.26 no.5D
• /
• pp.869-876
• /
• 2006

In the case of earthenware cultural heritages that are found in the form of fragments, the major task is quick and precise restoration. The existing method, which follows the rule of trial and error, is not only greatly time consuming but also lacked precision. If this job could be done by three dimensional scanning, matching up pieces could be done with remarkable efficiency. In this study, the original earthenware was modeled through three-dimensional pattern scanning and photogrammetry, and each of the fragments were scanned and modeled. In order to obtain images from the photogrammetry, we calibrated and used a Canon EOS 1DS real size camera. We analyzed the relationship among the sections of the formed model, efficiently compounded them, and analyzed the errors through residual and color error map. Also, we built a web-based three-dimensional simulation environment centering around the users, for the virtual museum.

• Geophysics and Geophysical Exploration
• /
• v.5 no.2
• /
• pp.84-92
• /
• 2002

In this study, the new modeling scheme has been developed for recently designed and tested electromagnetic survey, which adapts horizontal magnetic dipole with $1\;kHz\~1\;MHz$ frequency range as a source. The 2.5-D secondary field formulation in wavenumber domain was constructed using finite element method and verified through comparing results with layered-earth solutions calculated by integral equations. 2-D conductive- and resistive-block models were constructed for calculating electric field, magnetic field and impedance - the ratio of electric and magnetic fields which are orthogonal each other. This study showed that electric field and impedance are superior in identifying 2-D isolated-body model to magnetic field. In particular, impedance gives more stable results than electric field with similar spatial resolving power, because electric field is divided by magnetic field in impedance. Thus the impedance analysis which uses electric and magnetic fields together would give better result in imaging the shallow anomalies than conventional EM method.

• Journal of Korean Society for Geospatial Information Science
• /
• v.20 no.1
• /
• pp.117-123
• /
• 2012

Many nations have been launched their own earth observation satellites due to much interest in space exploration. Because of this, the number of high resolution satellite are increasing day by day. With the development of web environment, general users have easy access to satellite images. The research conducted a basic study about web-based satellite photogrammetry in order to determine three dimensional coordinates easily without having profound knowledge of satellite sensor modeling. Various element technologies were analyzed to decide three dimensional coordinates by using high resolution satellite images in web environment, and case studies were conducted by using IKONOS satellite images. By applying parallel projection model, which is one of sensor modeling methods, epipolar image was created and prototype form of program that can decide three dimensional location in web environment was implemented. Through this, general users could decide three dimensional location easily in web environment and knew that already existed spatial information can be renewed and used in service area.

• Journal of the Institute of Convergence Signal Processing
• /
• v.8 no.1
• /
• pp.15-21
• /
• 2007

We propose a 3D modeling method for surface inspection of non-constant velocity moving object. 1'lie laser lines reflect tile surface curvature. We can acquire 3D surface information by analyzing projected laser lines on object. In this paper, we use multi-line laser to improve the single stripe method and high speed of single frame. Binarization and edge extraction of frame image were proposed for robust laser each line extraction. A new labeling method was used for laser line labeling. We acquired some feature points for image matching from the frame data and juxtaposed the frames data to obtain a 3D shape image. We verified the superiority of proposed method by applying it to inspect container's damages.

• KSBB Journal
• /
• v.21 no.1 s.96
• /
• pp.59-67
• /
• 2006

2D spectrofluorometer produces many spectral data during fermentation processes. The fluorescence spectra are analyzed using chemometric methods such as principal component analysis (PCA), principal component regression (PCR) and partial least square regression (PLS). Analysis of the spectral data by PCA results in scores and loadings that are visualized in score-loading plots and used to monitor a few fermentation processes by S. cerevisae and recombinant E. coli. Two chemometric models were established to analyze the correlation between fluorescence spectra and process variables using PCR and PLS, and PLS was found to show slightly better calibration and prediction performance than PCR.

• Journal of Korea Multimedia Society
• /
• v.16 no.1
• /
• pp.108-118
• /
• 2013

Recently the 3D modeling techniques were developed rapidly due to rapid development of computer vision, computer graphics with the excellent performance of hardware. With the advent of a variety of 3D contents, 3D modeling technology becomes more in demand and it's quality is increased. 3D face models can be applied widely to such contents with high usability. In this paper, a 3D face modeling is attempted from a given single 2D frontal face image. To achieve the goal, we thereafter the feature points using AAM are extracted from the input frontal face image. With the extracted feature points we deform the 3D general model by 2-pass mesh warping, and also the depth extraction based on intensity values is attempted to. Throughout those processes, a universal 3D face modeling method with less expense and less restrictions to application environment was implemented and it's validity was shown through experiments.