• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1999.06a
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• pp.97.1-102
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• 1999

This paper porposes and efficient coding scheme for remote medical communication systems, or“telemedicine systems”. These systems require a technique which is able to transfer large volume of data such as X-ray images effectively. We have already developed a hierarchical image coding and transmission scheme (HITS), which achieves an efficient transmission of medical images simply[1]. In this paper, a new coding scheme for HITS is proposed, which used hierarchical context modeling for the purpose of improving the coding efficiency. The hierarchical context modeling divides wavelet coefficients into several sets by the value of a correspondent coefficient in their higher class, or“a parent”, optimizes a Golomb-Rice (GR) code parameter in each set, and then encodes the coefficients with the parameter. Computer simulation shows that the proposed scheme is effective with simple implementation. This is due to fact that a wavelet coefficient has dependence on its parent. As a result, high speed data transmission is achieved even if the telemedicine system consists of simple personal computers.

• Structural Engineering and Mechanics
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• v.56 no.4
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• pp.535-548
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• 2015

A series of experimental results on thin mild steel plates clamped at the boundary subjected to gas detonation shock loading are presented. Detonation occurred by mixing Acetylene (C2H2)-Oxygen (O2) in various volume ratio and different initial pressure. The applied impulse is varied to give deformation in the range from 6 mm to 35 mm. Analytical modeling using energy method was also performed. Dependent material properties, as well as strain rate sensitivity, are included in the theoretical modeling. Prediction values for midpoint deflections are compared with experimental data. The analytical predictions have good agreement with experimental values. Moreover, it has been shown that the obtained model has much less error compared with those previously proposed in the literature.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.383-389
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• 2003

Clay minerals show a distinct induced-polarization phenomenon, which is one of the most important factors for predicting groundwater flow and contaminant transport. This paper presents a step-by-step process to estimate Cole-Cole parameters from spectral induced-polarization (IP) data measured on the surface of three-dimensional earth. First, the inversion of low-frequency resistivity survey data is made to identify the dc resistivity ${\rho}_dc$ of a volume having IP effects. The other parameters, chargeability m, time constant $\tau$, and frequency dependence c, are sought for the polarizable volume. Next, using multi-frequency data, c can be obtained as high or low asymptotes of the slope of log phase vs. log frequency. Further, for low m, intrinsic $\tau$ is approximated by apparent one, ${\tau}_a$, which is derived from the relation ${{\omega}{\tau}}_a$=1 at an angular frequency $\omega$, where the imaginary component of spectral IP data has an extreme value. Finally, to obtain intrinsic m a two-step linearized procedure has been derived. For a body of given $\tau$ and c, forward modeling with a progression of m values yields a plot of observed vs. intrinsic imaginary components for a frequency. Since this plot is essentially linear, to extract the intrinsic imaginary component is quite simple with an observed value. Using the plot of intrinsic imaginary component vs. m, intrinsic m is determined. We present a synthetic example to illustrate that the Cole-Cole parameters can be recovered from spectral IP data.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.19-30
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• 2013

This study is to evaluate the use of dual-polarization radar data for storm runoff modeling in Namgang dam (2,293 $km^2$) watershed using KIMSTORM (Grid-based KIneMatic wave STOrm Runoff Model). The Bisl dual-polarization radar data for 3 typhoons (Khanun, Bolaven, Sanba) and 1 heavy rain event in 2012 were obtained from Han River Flood Control Office. Even the radar data were overall less than the ground data in areal average, the spatio-temporal pattern between the two data was good showing the coefficient of determination ($R^2$) and bias with 0.97 and 0.84 respectively. For the case of heavy rain, the radar data caught the rain passing through the ground stations. The KIMSTORM was set to $500{\times}500$ m resolution and a total of 21,372 cells (156 rows${\times}$137 columns) for the watershed. Using 28 ground rainfall data, the model was calibrated using discharge data at 5 stations with $R^2$, Nash and Sutcliffe Model Efficiency (ME) and Volume Conservation Index (VCI) with 0.85, 0.78 and 1.09 respectively. The calibration results by radar rainfall showed $R^2$, ME and VCI were 0.85, 0.79, and 1.04 respectively. The VCI by radar data was enhanced by 5 %.

• Journal of KIISE:Computing Practices and Letters
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• v.12 no.5
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• pp.286-299
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• 2006

Due to the continuing technical progress in the capabilities of modeling, simulation, and sensor devices, huge volume data with very high resolution are common. In scientific visualization, various interactive real-time techniques on high performance parallel computers to effectively render such large scale volume data sets have been proposed. In this paper, we present a mobile volume visualization system that consists of mobile clients, gateways, and parallel rendering servers. The mobile clients allow to explore the regions of interests adaptively in higher resolution level as well as specify rendering / viewing parameters interactively which are sent to parallel rendering server. The gateways play a role in managing requests / responses between mobile clients and parallel rendering servers for stable services. The parallel rendering servers visualize the specified sub-volume with rendering contexts from clients and then transfer the high quality final images back. This proposed system lets multi-users with PDA simultaneously share commonly interesting parts of huge volume, rendering contexts, and final images through CSCW(Computer Supported Cooperative Work) mode.

• Journal of Korea Game Society
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• v.10 no.1
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• pp.147-156
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• 2010

In this paper, we propose 3D cloud animation by cloud modeling method of 2D images retrieved from a meteorological satellite. First, on the satellite images, we locate numerous control points to perform thin-plate spline warping analysis between consecutive frames for the modeling of cloud motion. In addition, the spectrum channels of visible and infrared wavelengths are used to determine the amount and altitude of clouds for 3D cloud image reconstruction. Pre-integrated volume rendering method is used to achieve seamless inter-laminar shades in real-time using small number of slices of the volume data. The proposed method could successfully construct continuously moving 3D clouds from 2D satellite images at an acceptable speed and image quality.

• Journal of Korea Multimedia Society
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• v.5 no.5
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• pp.599-607
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• 2002

The octree model, a hierarchical volume description of 3D objects, nay be utilized to generate projected images from arbitrary viewing directions, thereby providing an efficient means of the data base for 3D object recognition and other applications. We present 2D projected image and made pseudo gray image of object using octree model and multi level boundary search algorithm. We present algorithm for finding feature points of 2D and 3D image and finding matched points using geometric transformation. The algorithm is made of data base, it will be widely applied to 3D object modeling and efficient feature points application for basic 3D object research.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.621-626
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• 2021

In this study, data on the study site for apartment construction was acquired, and the quantity of construction waste was calculated using a drone and mobile 3D laser scanner. The accuracy of the drone was 0.034 to 0.064m in the horizontal and vertical directions, respectively, and the mobile 3D Laser Scanner showed an accuracy of 0.018 to 0.049m in the horizontal direction, respectively. These results suggest that it is possible to construct spatial information using a drone and mobile 3D laser scanner with a value within the allowable accuracy of 1:1,000 digital terrain. The volume of construction waste calculated using the mobile 3D laser scanner data was 70,797㎥. It was possible to calculate the volume on the side of the building or some facilities that appeared as shaded areas in the drone outcomes. In addition, modeling was performed for view analysis of the apartments scheduled to be constructed and the terrain-based modeling results of the surrounding buildings. In the future, data construction and accuracy evaluation using mobile 3D laser scanners will be conducted. In addition, additional research comparing existing methods and work processes will be carried out, and the efficiency of mobile 3D laser scanners in the field of spatial information construction can be presented.

• Journal of information and communication convergence engineering
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• v.5 no.4
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• pp.369-373
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• 2007

RFID systems large volume of data, it can lead to slower queries. To achieve better query performance, we can partition into active and some nonactive data. In this paper, we propose two approaches of partitioning for efficient query support. The one is average period plus delta partition and the other is adaptive average period partition. We also present the system architecture to manage active data and non-active data and logical database schema. The data manager check the active partition and move all objects from the active store to an archive store associated with an average period plus data and an adaptive average period. Our experiments show the performance of our partitioning methods.

• Journal of Digital Contents Society
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• v.15 no.4
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• pp.521-526
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• 2014

The purpose of this study is to propose the efficient method of 3D data registration. Three-dimensional data including the two-dimensional image acquisition apparatus and the position information are acquired at an arbitrary angle with each other. This paper proposes the more accurate and faster matching method by using this information. Four image points founded from 2D images match the volumetric size of the model and compute the homography of the axis for registration between two 3D data sets. The advantages of the proposed algorithm are the repeating process is unnecessary and the process time is faster than prvious method.