• Proceedings of the Korean Society of Computer Information Conference
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• 2016.07a
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• pp.167-168
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• 2016

본 논문에서는 스마트폰을 이용하여 수학을 공부할 수 있는 지오지브라의 활용 방안을 제안하였다. 특히 원 및 원기둥 등 도형의 면적 계산 개념을 제안한 아르키메데스의 사고를 지오지브라를 활용하여 할 수 있는 구체적인 자료를 개발하였다. 이러한 자료를 통해 학생들은 도형의 면적을 구하는 공식을 암기하기 않고 스스로 이해하면서 아르키메데스가 제안한 불가불량의 개념을 통해 다양한 도형의 면적과 체적을 구하는 방법을 이해할 수 있을 것이다. 특히 수학을 어려워하는 학생들에게 머릿속으로 사고하기 어려운 내용을 컴퓨터라는 도구를 활용하여 이해할 수 있도록 하였다는 점에서 의미가 있다.

• Proceedings of the IEEK Conference
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• 2003.11b
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• pp.247-250
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• 2003

This paper proposed to digital watermarking technique for architectural drawing using LINES and ARCs based on vertex in CAD system to prevent infringement of copyright from unlawfulness reproductions and distribution. After extract LINES and ARCs from designed drawing, we embed watermarks using adaptive algorithm in each characteristics. Watermarks robust to various attacks like as geometrical transformation as being embedded in LINE's length and ARC's angle information. Also, the proposed method satisfies enough transparency about watermarked drawing because have suitable embedding strength to each component. By experimental result, we confirmed robustness and invisibility of embedded watermarks in several conversions of architectural design drawing.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.55-63
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• 1997

Precision digital data capture and spatial analysis system to cultural properties play important roles in preserving the existing properties. This study presents the acquisition oi digital data in geometrical context and spatial analysis for more effective management to cultural properties. Established in the same coordinates system, Precision 3D measurements and image analysis were peformed. In addition, geometrical analysis, and 3D monitoring to Songsanri Royals Tombs in Gongju were carried out in generating basedata for conservation plan.

• Proceedings of the KWS Conference
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• 2005.06a
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• pp.91-93
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• 2005

Forming sheet metal by laser-induced thermal stresses (laser forming) has been extensively studied, and the research has focused on two-dimensional geometries using a multi-pass straight line scan. Recently there came out some useful studies or three-dimensional laser forming which is applied to doubly curved shapes. The task of 3D laser forming sheet metal is to determine a set of process parameters such as laser scanning paths, laser power and scanning speed that will make a given shape. New method for laser forming of a doubly curved surface by using geometrical information was proposed and verified by experiments. This method shows good performance in the sense of calculation time and accuracy compared to the inherent strain method.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.4 no.4
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• pp.901-905
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• 2000

An elliptical ogive head for a generic missile is proposed to reduce its detectable probability from aground defense radar. Numerical RCS results of a generic missile with an elliptical ogive head are evaluated using the GTD/UTD (Geometrical Theory of Diffraction/uniform GTD). The results are compared with those of a cylindrical ogive head. In the sense of aerodynamics, the performance evaluation of an elliptical ogive head for a generic missile should be followed.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.11
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• pp.2292-2298
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• 2009

In this paper, the lossy image compression algorithm using the quad tree and the bandlets is proposed. The proposed algorithm transforms input images by the discrete wavelet transform (DWT) and represents the geometrical structures of high frequency bands using the bandlets with a 8 block- size. In addition, the proposed algorithm searches the position information of the significant coefficients by using the quad tree algorithm and computes the magnitude and the sign information of the significant coefficients by using the Embedded Image Coding using Zerotrees of Wavelet Coefficients (EZW) algorithm. The compression result by using the quad tree algorithm improves the PSNR performance of high frequency images up to 1 dB, compared to that of JPEG-2000 algorithm and that of S+P algorithm. The PSNR performance by using DWT and bandlets improves up to 7.5dB, compared to that by using only DWT.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.2C
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• pp.194-199
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• 2009

This paper proposes a face detection algorithm that uses geometrical information on face and hair region. This information that face adjoins hair regions can be the important one for face detection. It is also kept in images with frontal, rotated and lateral face. The face candidates are founded by the analysis of skin regions after detecting the skin and hair color regions in an image. Next, the intersected lesions between face candidates and hair's are created. Finally, the face candidates that include the subsets of these regions turn out to be face. Experimental results showed the high detection rates for frontal and lateral faces as well as faces geometrically distorted.

• 한국지형공간정보학회:학술대회논문집
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• 2000.12a
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• pp.29-40
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• 2000

• The KIPS Transactions:PartB
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• v.9B no.4
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• pp.491-500
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• 2002

In this paper, we propose a real-time face detection and recognition system by using skin color informations, geometrical feature vectors of face, and facial angle informations from color face image. The proposed algorithm improved face region extraction efficiency by using skin color informations on the HSI color coordinate and face edge information. And also, it improved face recognition efficiency by using geometrical feature vectors of face and facial angles from the extracted face region image. In the experiment, the proposed algorithm shows more improved recognition efficiency as well as face region extraction efficiency than conventional methods.

• The KIPS Transactions:PartB
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• v.12B no.3 s.99
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• pp.283-290
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• 2005

The mismatched allocation of watermarking position due to parallel translation, rotation, and scaling distortion is a problem that requires an answer in watermarking. In this paper, we propose a watermarking method robust enough to hold against geometrical distorting using restoration pattern matching. The proposed method defines restoration pattern, then inserts the pattern to a watermark embedded image for distribution. Geometrical distortion is verified by comparing restoration pattern extracted from distributed image and the original restoration pattern inserted to the image. If geometrical distortion is found, inverse transformation is equally performed to synchronize the watermark insertion and extraction position. To evaluate the performance of the proposed method, experiments in translation, rotation, and scaling attack are performed.