• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.718-720
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• 2004

n개의 점과 이를 포함하는 직사각형 B가 주어졌을 때 B내에서 어떤 점도 포함하지 않는 가장 큰 직사각형을 찾는 선형 근사 알고리즘을 제시한다. 찾게 되는 직사각형은 좁고 긴 모양의 것은 피하며 직사각형 B의 변에 평행해야 할 필요는 없다. 모든 방향을 고려하여 가장 큰 직사각형을 근사율 (1+$\alpha$)로 O(n + (area(B)/($\alpha$l)$^2$) log$^2$($\alpha$/$\varepsilon$)) 시간 내에 구한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1621-1624
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• 2004

본 논문에서는 2차원 공간상에서 윈도우에 출력되는 사각형 이미지가 윈도우 영역을 벗어날 때 영역 패턴을 이용한 절단 알고리즘을 제안한다. 제안하는 알고리즘은 Cohen-Sutherland의 알고리즘을 응용하여 사각형 이미지의 절단영역을 계산하는데, 약 4회의 조건문장과 1회의 분기문장을 사용하여 수행되므로 기존의 방법보다 전체적인 수행 성능이 약 12% 좋게 나타났으며, 특히 확장영역에 있어 기존의 방법은 처리하지 못하는 부분까지도 완벽하게 처리됨을 확인 할 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1457-1460
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• 2013

We propose a flexible camera calibration system for mobile platform to calibrate the camera's intrinsic parameters which based on the geometrical property of the vanishing points determined by two perpendicular groups of parallel lines. The system only requires the camera to observe a rectangle card show at a few(at least four)different orientation. The experimental results of the real images show the proposed calibration system in this paper is easy to use and robust.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.49 no.3
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• pp.18-29
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• 2012

Viola-Jones algorithm, a very effective real-time object detection method, uses Haar-like features to constitute weak classifiers. A Haar-like feature is made up of at least two rectangles each of which corresponds to either positive or negative areas and the feature value is computed by subtracting the sum of pixel values in the negative area from that of pixel values in the positive area. Compared to the conventional Haar-like feature which is made up of more than one rectangle, in this paper, we present a couple of new rectangular features whose feature values are computed either by the sum or by the variance of pixel values in a rectangle. By the use of these rectangular features in combination with the conventional Haar-like features, we can select additional features which have been excluded in the conventional Viola-Jones algorithm where every features are the combination of contiguous bright and dark areas of an object. In doing so, we can enhance the performance of object detection without any computational overhead.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.558-561
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• 2009

In this paper, we propose Simple Frame Marker(SFMarker) to support recognition of characters and images included in a marker in augmented reality. If characters are inserted inside of marker and are recognised using Optical Character Recognition(OCR), it doesn't need marker learning process before an execution. It also reduces visual disturbance compared to 2D barcode marker due to familarity of characters. Therefore, proposed SFMarker distinguishes Square SFMarker that embeds images from Rectangle SFMarker with characters according to ratio of marker and applies different recognition algorithms. Also, in order to reduce preprocessing of character recognition, SFMarker inserts direction information in border of marker and extracts it to execute character recognition fast and correctly. Finally, since the character recognition for every frame slows down tracking speed, we increase the speed of recognition process using the result of character recognition in previous frame when frame difference is low.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.40 no.6
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• pp.9-21
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• 2003

In this paper, we propose a new submesh allocation scheme which improves the performance of multicomputer systems. The key idea of this allocation scheme is to reduce waiting time of task by minimizing the submesh search time and the submesh a]location delay caused by external fragmentation. This scheme reduces the submesh search time by classifying independent free submeshes according to their types (square, horizontal rectangle, vertical rectangle) and searching a best-fit submesh from the classified free submesh list. If a submesh allocation delay occurs due to external fragmentation, the proposed scheme relocates tasks, executing In allocated submeshes, to another free submeshes and compacts processor fragmentation. This results in reducing the submesh allocation delay. Through simulation, we show that it is more effective to reduce the submesh allocation delay due to external fragmentation than reducing the submesh search time with respect to the waiting time of task. We also show that the proposed strategy improves the performance compared to previous strategies.

• Journal of KIISE
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• v.44 no.3
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• pp.246-252
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• 2017

In this paper, we present an algorithm that computes a minimum-width color spanning axis-parallel rectangular annulus. A rectangular annulus is a closed region between a rectangle and its offset, and it is thus bounded by two rectangles called its outer and inner rectangles. The width of a rectangular annulus is determined by the distance between its outer and inner rectangles. Given n points in the plane each of which has one of the prescribed k colors, we call a rectangular annulus color spanning if it contains at least one point for each of the k colors. Prior to this work, there was no known exact algorithm that computes a minimum-width color-spanning rectangular annulus. Our algorithm is the first to solve this problem and it runs efficiently in $O((n-k)^3nlogn)$ time.

• Journal of Digital Contents Society
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• v.16 no.4
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• pp.615-622
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• 2015

Recently virtual advertising is located in an important area of interest in the TV market by convenience of application and reduction of cost. The methods of inserting a virtual advertising in broadcasting are Up-link that method insert the image through the production equipment of the broadcasting station and dispatch equipment and technical personnel in the shooting and Down-streaming that method insert a virtual image automatically in relay video using image processing technology. In recent years, the image processing technology is an important research area in the virtual advertising area for automatically insertion of advertising images. In this paper, we propose the method to extract less-informative region in sports video using image processing. The proposed method extracts less-Informative region through rectangle detection of Hough transform and analysis of color histogram distribution.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.1
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• pp.45-53
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• 2009

A possibility of the drag coefficient estimation in numerical water basins was discussed where the numerical solution were calculated by the 3-dimensional hydro-dynamical model (FLOW-$3D^{(R)}$) with the RNG $k-{\varepsilon}$ turbulence model. On the known cases of the drag coefficients for a rectangle, the numerical drag coefficients got $1.34{\sim}1.52$ and the wind tunnel values were $1.3{\sim}1.5$. For a cylinder, the numerical values were calculated as $0.75{\sim}0.78$ in the range of 0.5

• Journal of Fashion Business
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• v.11 no.4
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• pp.204-220
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• 2007

The background of Korean Ethnical Costume was originated from those northern mounted nomadic groups, which was Scythe style Costume Culture. Through the antique records and paintings of tombs bequests hereby describe the forms of Scythian Cotume (1) Headgear : There was Conical Cap(or Pointed Cap), Feathered Cap, and Crown. (2) Clothes : Both Men and Women wore Jacket as upper garment with leftsided collars, narrow sleeves to the length of the hip line. As lower garment, they wore the tight Trousers and Kungo(:窮袴)that was attached with gusset. (3) Belts and Boots : On the upper garment bound the leather Belts that was hanged a hook that was shaped of animal form at the end. Scythian Buckles was divided into six groups, animal-shaped, animal's head shaped, animal fight-shaped, rectangle-shaped, rectangle openwork-shaped, genre scene shaped Buckle. To the Boots, they wore leather boots. (4) Ornaments : Ornaments divided into Dress Trimming(:Gold plaques), Earrings, Necklaces(;Torques), Bracelets, Rings. Scythian Gold Plaques were divided into several types according to the shape, animal style(curved beast shape, profile shape, head reversed over its back shape), round shape, quadrilateral form, star shape, flower shape, crescent shape, bundle shape, human appearance. Earrings consisted of a plain ring and pendant ring was a middle ornament hung from it to a pendants which hung was made of heart shaped leaves of the tree, beads-linked. Scythian Torques were divided into several types according to the shape, Torque with Terminal style, Spiral style, Layers style, Crescent-shaped pectoral style, Crown style. Scythian Bracelet were divided into 4 styles according to the shape, Bracelets with ends shaped like beasts style, Spiral style, Layers style, Crown with openwork style. Rings were rhomb-shaped and animal shaped styleRings (5) Animal motifs used in Scythian ornaments appears that in some cases the work was intended to be purely ornamental, while many times the motifs had symbolic meaning (such as the successful dominance of the aggressor over the victim portrayed in the attack scenes). Magical use of symbols may have been inten-ded to guarantee the power of the aggressor.