• Journal of Korea Water Resources Association
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• v.43 no.11
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• pp.985-994
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• 2010

Typoon Maemi landed on the southern coast of Korean Peninsula at 21:00, September 12, 2003 with a central pressure of 950 hPa. A three dimensional (3D) inundation model was established to calculate the storm surge and flooded area due to Typoon Maemi. A field survey of storm surge traces in Masan City was carried out to evaluate the inundation water depth. Hydromet-Rankin Vortex model was used to calculate the atmospheric pressure and the surface wind fields. The inundation area, storm surge and typoon-induced current were calculated using the 3D model. The peak of computed storm surge in Masan Port using the 3D model was 238 cm, and the observed peak was 230 cm. The simulated storm surge and the inundation area showed good agreement with field survey data. The comparison of the 3D and the two dimensional (2D) models of storm surge was carried out, and the 3D model was more accurate. The computed typoon-induced currents in the surface layer of Masan Bay went into the inner bay with 30~60 cm/s, while the currents in the bottom layer flowed out with 20~40 cm/s.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.3
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• pp.233-238
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• 2005

3-D virtual city model is becoming increasingly important for a number of GIS applications. For reconstruction of 3D building in urban area aerial images, satellite images, LIDAR data have been used mainly and most of researches related to 3-D reconstruction focus on development of method for extraction of building height and reconstruction of building. In case of automatically extracting and reconstructing of building height using only aerial images or satellite images, there are a lot of problems, such as mismatching that result from a geometric distortion of optical images. Therefore, researches of integrating optical images and existing digital map (1/1,000) has been in progress. In this paper, we focused on extracting of building height by means of interest points and vertical line locus method for reducing matching points. Also we used digital plotter in order to validate for the results in this study using aerial images (1/5,000) and existing digital map (1/1,000).

• Journal of Korea Water Resources Association
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• v.45 no.2
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• pp.229-242
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• 2012

This study presents a physical habitat modeling of adult Zacco platypus in a reach of the Dalcheon Stream located downstream of the Goesaan Dam. CASiMiR model is used to estimate habitat suitability index based on the fuzzy logic. Results are compared with those from River2D model, which uses habitat preference curve for habitat suitability index. Hydraulic data simulated by River2D are used as input data for CASiMiR model after verification against field measurements. The result shows that the habitat suitability of the adult Zacco platypus is maximum around the riffle area located upstream of the bend. CASiMiR and River2D estimate the maximum weighted usable areas at the discharge rates of 7.23 $m^3/s$ and 9.0 $m^3/s$, respectively. Overall comparison of the two models employed in this study indicates that CASiMiR model overestimates the weighted usable area by 0.3~25.3% compared with River2D model in condition of drought flow (Q355), low flow (Q275), normal flow (Q185), and average-wet flow (Q95).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.497-505
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• 2018

In a situation where the amount of bulky waste needs to be quantified, a three-dimensional model of the wastes can be constructed using drones. This study constructed a drone-based 3D model with a range of flight parameters and a GCPs survey, analyzed the relationship between the accuracy and time required, and derived a suitable drone application technique to estimate the amount of waste in a short time. Images of waste were photographed using the drone and auto-matching was performed to produce a model using 3D coordinates. The accuracy of the 3D model was evaluated by RMSE calculations. An analysis of the time required and the characteristics of the top 15 models with high accuracy showed that the time required for Model 1, which had the highest accuracy with an RMSE of 0.08, was 954.87 min. The RMSE of the 10th 3D model, which required the shortest time (98.27 min), was 0.15, which is not significantly different from that of the model with the highest accuracy. The most efficient flight parameters were a high overlapping ratio at a flight altitude of 150 m (60-70% overlap and 30-40% sidelap) and the minimum number of GCPs required for image matching was 10.

• Journal of the Korean Data and Information Science Society
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• v.25 no.1
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• pp.177-185
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• 2014

Under bivariate normal distribution assumptions, the interaction and quadratic terms are needed in the logistic regression model with two predictors. However, depending on the correlation coefficient and the variances of two conditional distributions, the interaction and quadratic terms may not be necessary. Although the need for these terms can be determined by comparing the two scatter plots, it is not as useful for interaction terms. We explore the structure and usefulness of the 3-D residual plot as a tool for dealing with interaction in logistic regression models. If predictors have an interaction effect, a 3-D residual plot can show the effect. This is illustrated by simulated and real data.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.4
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• pp.251-257
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• 2011

In the present study, a 3-dimensional (3D) numerical model was developed to mimic the micro porous structure of a geological $CO_2$ storage reservoir. Especially, 3D modeling technique assigning random pore size to a 3D micro porous structure was devised. Numerical method using CFD (computational fluid dynamics) was applied for the 3D micro porous structure to calculate supercritical $CO_2$ flow field. The three different configurations of 3D micro porous model were designed and their flow fields were calculated. For the physical conditions of $CO_2$ flow, temperature and pressure were set up equivalent to geological underground condition where $CO_2$ fluid was stored. From the results, the characteristics of the supercritical $CO_2$ flow fields were scrutinized and the influence of the micro pore configuration on the flow field was investigated. In particular, the pressure difference and consequent $CO_2$ permeability were calculated and compared with increasing $CO_2$ flow rate.

• Journal of Korea Technology Innovation Society
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• v.21 no.2
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• pp.663-683
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• 2018

This study aims to analyze the effectiveness of R&D tax credit for SMEs. We surveyed to collect the information on firm's financial statements and R&D tax credit during 2014-2016, and implemented fixed effect model, random effect model and panel negative binomial model. The results show that the effect of R&D tax credit is 5.3 times larger in terms of R&D expenditure and 4.3 times bigger in terms of number of researchers than that of R&D subsidy. In addition, the effect of tax credit on non-metropolitan area companies is higher than that in the metropolitan area. Based on these results, we suggests three ways to improve the R&D tax incentive system for SMEs; To convert unused R&D tax credit of the start-ups to tax points, to exempt the minimum tax rate on R&D expenditure in equipment, and to unify the operation of various R&D tax credit institution.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2009.11a
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• pp.99-102
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• 2009

본 연구에서는 실제 기증받은 시체를 이용하여 인체의 각 구조물을 실제 모습 그대로 3D 이미지화하는 과정에 대해 알아보았다. 인체의 구조물을 3D 로 이미지화하는 과정은 다음과 같다. 먼저 시체를 0.2mm 간격으로 절단하여 절단면의 사진을 찍은 후, 각 절단면의 사진에서 각각의 구조물을 구역화하여 색칠을 한 후, 구역화한 이미지에서 외곽선을 추출하여 벡터 이미지를 만든다. 이 외곽선을 1mm 간격으로 쌓아 올린 후 그 표면을 재구성하여 3D 이미지로 변환하는 과정으로 진행되었다. 3D 이미지의 제작은 가슴 부위에 한정하여 이루어졌다. 인체의 해부학적인 모형을 3D 이미지로 시각화함으로써 얻는 효과는 일반인을 대상으로 인체의 내부에 대한 시각적인 호기심을 충족시켜주고 의학 상식을 넓히는데 도움을 줄 수 있을 것 이다. 또한 의대생들을 비롯한 의학 전문가들에게는 생생한 해부학 강의용으로도 활용 가능하다. 향후 Haptic 시스템을 이용한 의료 실습 어플리케이션과 접목될 수도 있을것이고, fMRI 데이터를 비롯한 타 데이터와의 융합을 통해 시각화하여 서비스 할 수도 있다. 이처럼 인체의 3D 모형은 의료분야에서 광범위하게 활용될 수 있는 데이터로써 그 가치를 지닐 것이다.

• Korean Journal of Optics and Photonics
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• v.18 no.5
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• pp.337-344
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• 2007

In recent years, there has been rapid progress in different areas of vision science, such as refractive surgical procedures, contact lenses and spectacles, and near vision. This progress requires a highly accurate modeling of optical performance of the human eyes in different accommodation states. A new novel model-eye was designed using the Navarro accommodation-dependent finite model eye. For each of the vergence distances, ocular wavefront error, accommodative response, and visual acuity were calculated. Using the new model eye ocular wavefront error, accommodation dative response, and visual acuity are calculated for six vergence stimuli, -0.17D, 1D, 2D, 3D, 4D and -5D. Also, $3^{rd}\;and\;4^{th}$ order aberrations, modulation transfer function, and visual acuity of the accommodation-dependent model eye were analyzed. These results are well-matched to anatomical, biometric, and optical realities. Our corrected accommodation-dependent model-eye may provide a more accurate way to evaluate optical transfer functions and optical performances of the human eye.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.785-790
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• 2009

섬진강 하구역에서 모래채취로 인한 지형변화와, 댐 및 취수장의 증가로 인한 유량감소로 인해 해수의 역류범위가 증가하여 참게나 재첩과 같은 경제성 어종이 감소하고, 염분으로 인한 농업용수사용 불가와 같은 염수피해가 늘어가고 있다. 따라서 본 연구에서는 2차원 수치모형인 RMA-2, 4와 3차원 수치모형인 EFDC를 각각 이용하여 밀물 시 염수가 전파되는 범위 및 염수농도를 모의하고, 동시에 2차원 모형과 3차원 모형을 비교하여 모의목적에 대한 각 모형의 장 단점을 알아보았다. 모의결과를 살펴보면 최저 수위 시 두 모형이 큰 차이를 보이는 것을 볼 수 있었으며, EFDC가 상류쪽으로 더 길게 염수침입이 일어나는 것을 볼 수 있었다.