• Proceedings of the Korea Multimedia Society Conference
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• 2001.06a
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• pp.29-32
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• 2001

현재 뇌 질환의 진단은 전문의의 주관극인 판단에 의하기 때문에 보다 정량화되고 객관화된 근거를 제시할 수 있는 의료 영상 정보 분석 시스템이 필요하다. 본 시스템은 MR 영상에 대해 영상 처리 및 정보 관리를 통한 뇌 질만의 진단 및 계획이나 방법의 결정을 하는데 도움을 주기 위한 지식기반 의료 영상 처리 및 관리 시스템으로 의료 영상의 처리와 진단, 영상처리시스템 이용의 극대화, 시스템간의 유기적 연결 및 운용상의 문제점 등 의학영상에 관한 제반 연구를 수행함으로써 국내의 의료영상 기술을 선도하며, 의학영상분야 및 의과학 발전에 기여할 수 있을 것으로 생각된다.

• The Journal of Information Technology
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• v.3 no.1
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• pp.61-72
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• 2000

In this paper, we propose a bit-sliced modular multiplication algorithm and a bit-sliced modular multiplier design meeting the increasing crypto-key size for RSA public key cryptosystem. The proposed bit-sliced modular multiplication algorithm was designed by modifying the Walter's algorithm. The bit-sliced modular multiplier is easy to expand to process large size operands, and can be immediately applied to RSA public key cryptosystem.

• Journal of the Korean Society of Visualization
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• v.14 no.2
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• pp.46-51
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• 2016

In this study, a Masked Omni-Directional Integration(MODI) method for pressure calculation is proposed using the Particle Image Velocimetry (PIV) data. To obtain the velocity field, the Affine PIV method was adopted. Synthetic images were generated for a solid body rotation. Calculation on the pressure was based on the Navier-Stokes equation. The results obtained by the MODI were compared with those obtained by theoretical pressure and by the Omni-Directional Integration(ODI) method. It was shown that the minimum error by the proposed MODI method was attained when the mask size was 1.

• Journal of the Korean Society of Visualization
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• v.10 no.1
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• pp.55-59
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• 2012

Reverse Design(RD) plays an important role in simulation engineering, such as CFD (Computational Fluid Dynamics) and Virtual Engineering and Design. RD becomes much more valuable when there is no shape data of the practical models for CFD grid generations. In this study, two-camera based rapid prototyping(RP) system is proposed. 3D-PTV based measurement algorithm was adopted. The developed system was applied to reconstruct three-dimensional data of a human face, a motorcycle model, a cylindrical body and a triangular pyramid.

• Journal of the Korean Society of Visualization
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• v.8 no.4
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• pp.26-30
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• 2010

A PTV algorithm was constructed using a linear transformation, in which the merits of the conventional PIV and PTV were adopted. In PIV calculations, the obtained velocity vectors are affected by the filtering effects by its calculation principle. PTV techniques are widely used for their excellences of measuring small scaled flows, such as nano and bio flows. However, PTVs produce vector errors due to interpolation process. To overcome these problems, a hybrid PTV algorithm was constructed by combining PTVs' and PIVs' benefits using a linear transformation. The Taylor-Green vortex flows were generated for the tests of vorticity calculations. The conventional gray-level cross-correlation PIV technique and 2-Frame PTV technique were tested for the same flows for comparisons with those obtained by the constructed hybrid algorithm. The excellence of the constructed hybrid algorithm was validated through an actual experiment on the cylinder wake.

• Journal of the Korean Society of Visualization
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• v.17 no.3
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• pp.66-69
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• 2019

An image compensating algorithm with high-vibration movement is proposed, using optical flow and the Kalman Filter. The temporal motion vector field is calculated by Optical flow and suspicious vectors are removed or adjusted by the Gaussian interpolation method. The high-vibrated vector filled is stabilized by the Kalman filter. Lastly, compensated images are obtained by affine transformation. This proposed algorithm gives good compensated video images on high-vibration situations.

• Journal of the Korean Society of Visualization
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• v.19 no.1
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• pp.94-99
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• 2021

In order to increase the efficiency of thermoelectric refrigerators using the Peltier effect, it is necessary to optimize the distribution of the flow of cold air from the fan. In this study, the flow flowing upwards and downwards while changing the area of the flow path was visualized using the PIV technique for the control of cold air in a thermoelectric refrigerator. From these results, the flow rate according to the change in the area of the flow path was confirmed, and design criteria for optimizing the distribution of cold air flowing to the top and bottom of the refrigerator were suggested.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.1
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• pp.21-40
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• 2023

This study analyzed the cold air characteristics of the Nakdong Jeongmaek, which is advantageous for the formation of cold air that can flow into the city, in order to suggest the wind ventilation corridor plans, which have recently been increasing interest as a way to improve the urban thermal environment. In addition, based on the watershed analysis, specific cold-air watershed areas were established and management plans were suggested to expand the cold air function of the Nakdong Jeongmaek. As a result of the analysis of cold air in the Nakdong Jeongaek, cold air was strongly generated in the northern forest of the Jeongamek, and flowed into nearby cities along the valley topography. On average, the speed of cold air was high in cities located to the east of the Jeongmaek, while the height of cold air layer was high in cities located to the west. By synthesizing these cold air characteristics and watershed analysis results, the cold-air watershed area was classified into 8 zones, And the plans were proposed to preserve and strengthen the temperature reduction of the Jeongmaek by designating the zones as 'Conservation area of Cold-air', 'Management area of Cold-air', and 'Intensive management area of Cold-air'. In addition, in order to verify the temperature reduction of cold air, the effect of night temperature reduction effect was compared with the cold air analysis using weather observation data. As a result, the temperature reduction of cold air was confirmed because the night temperature reduction was large at the observation station with strong cold air characteristics. This study is expected to be used as basic data in establishing a systematic preservation and management plan to expand the cold air function of the Nakdong Jeongmaek.

• Journal of the Korean Association of Geographic Information Studies
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• v.26 no.2
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• pp.68-81
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• 2023

This study aims to establish a scenario based on the spacing and arrangement of the roadside trees to reduce heat waves and fine dust in cities that occurred during the urbanization process and to quantitatively analyze the degree of reduction. The ENVI-met 5.0.2v model, a micro-climate simulation program, was used to analyze the degree of improvement in the thermal environment and fine dust according to the roadside tree scenario. As a result of temperature analysis according to street tree spacing, the narrower the distance between roadside trees, the lower the temperature during the day as the number of planted trees increased, and a similar pattern was shown regardless of the distance between roadside trees in the morning and evening. In the case of fine dust emitted from the road, the concentration of fine dust increased slightly due to the increase in roadside trees, but the concentration of sidewalks where people walk increased slightly or there was no difference because of blocking fine dust on trees. The temperature according to the arrangement of street trees tended to decrease as the number of planted trees increased as the arrangement increased. However, not only the amount of trees but also the crown projected area was judged to have a significant impact on the temperature reduction because the temperature reduction was greater in the scenario of planting the same amount of trees and widening the interval of arrangement. In terms of the arrangement, the fine dust concentration showed a difference from the results according to the interval, suggesting that the fine dust concentration may change depending on the relationship between the main wind direction and the tree planting direction. By quantitatively analyzing the degree of thermal environment and fine dust improvement caused by roadside trees, this study is expected to promote policies and projects to improve the roadside environment efficiently, such as a basic plan for roadside trees and a project for wind corridor forests.

• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.3
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• pp.31-38
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• 2019

This study quantified, through a direct harvesting method, storage and annual uptake of carbon from open-grown trees for three landscape tree species frequently planted in the southern region of Korea, and developed quantitative models to easily estimate the carbon reduction by tree growth for each species. The tree species for the study included Camellia japonica, Lagerstroemia indica, and Quercus myrsinaefolia, for which no information on carbon storage and uptake was available. Ten tree individuals for each species (a total of 30 individuals) were sampled considering various stem diameter sizes at given intervals. The study measured biomass for each part of the sample trees to quantify the total carbon storage per tree. Annual carbon uptake per tree was computed by analyzing the radial growth rates of the stem samples at breast height or ground level. Quantitative models were developed using stem diameter as an independent variable to easily calculate storage and annual uptake of carbon per tree for study species. All the quantitative models showed high fitness with $r^2$ values of 0.94-0.98. The storage and annual uptake of carbon from a Q. myrsinaefolia tree with dbh of 10 cm were 24.0 kg and 4.5 kg/yr, respectively. A C. japonica tree and L. indica tree with dg of 10 cm stored 11.2 kg and 8.1 kg of carbon and annually sequestered 2.6 kg and 1.2 kg, respectively. The above-mentioned carbon storage equaled the amount of carbon emitted from the gasoline consumption of about 42 L for Q. myrsinaefolia, 20 L for C. japonica, and 14 L for L. indica. A tree with the diameter size of 10 cm annually offset carbon emissions from gasoline use of approximately 8 L for Q. myrsinaefolia, 5 L for C. japonica, and 2 L for L. indica. The study pioneers in quantifying biomass and carbon reduction for the landscape tree species in the southern region despite difficulties in direct cutting and root digging of the planted trees.