• Journal of Korea Game Society
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• v.10 no.4
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• pp.63-71
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• 2010

In this paper, we propose a boundary based marker binary coding method for augmented reality games, which enables the marker-area to be binary coded well in any lighting environments. First, it detects the boundary after transforming an original marker image to a gray scale image, and it executes 4 way pixel extensions for all boundary pixels in order to make the boundary to closed area. Next, for all boundary pixels it compares the brightness of right and left ones of each pixel and allocates black for the lower side and white for the higher side by filling inside area thru the seeded region growing. Experimental results showed that our proposed method produces a good binary marker image recognizable in various light environments. In addition, it showed the possibility of real-time calculation by considering the result of operation speed which is 51 fps for VGA image.

• Journal of Korea Multimedia Society
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• v.13 no.10
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• pp.1463-1473
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• 2010

In this paper, we propose a modified watershed algorithm to extract more correct edge and reduce processing time. Two new algorithms are proposed in this paper. The first one is applying two conventional watershed expansion methods known as rainfall and immersion simulation jointly. We analyze the advantage and problem of each simulation and then propose a new expansion method that keeps the advantage and removes the problem in order to extract more correct edge and reduce processing time. The second is a new priority decision algorithm to obtain more correct edge of a region. Some zero-crossing points of gradient are expected to be edge of a region but the conventional method has a limitation that it cannot extract those points as edge. Therefore we propose a new priority decision algorithm for watershed in order to get more correct edge. We compare the proposed method with the conventional method through experiments and prove that the proposed method can extract more correct edge of region.

• Journal of the Korea Society of Computer and Information
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• v.12 no.4
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• pp.61-68
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• 2007

Two experiments examined the visual memory distortion by presenting 170 subjects with wide-angle views of four scenes on monitor screen. Retention interval of 0, 1 and 48 hours tested in reproduction and recognition experiment. The results of reproduction showed that the subjects tend to magnify the foreground and background of scenes compared to the real input (scene) for all retention intervals. The viewers recognized mure wide-angle views for the same scenes at the retention interval of 1 and 48 hours. These results demonstrated boundary extension is not a robust and unidirectional phenomenon but boundary contraction can be occurred with wide-angle views. The results also suggested that boundary contraction is the product of the activation of a memory schema hypothesis: In memory the representation moves toward a prototypical view and prototypical object size.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8A
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• pp.679-688
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• 2012

In this paper, performance improved hole-filling algorithm including boundary noise removing pre-process which can be used for an arbitrary view synthesis with given two views is proposed. Boundary noise usually occurs because of the boundary mismatch between the reference image and depth map and common-hole is defined as the occluded region. These boundary noise and common-hole created while synthesizing a virtual view result in some defects and they are usually very difficult to be completely recovered by using only given two images as references. The spiral weighted average algorithm gives a clear boundary of each object by using depth information and the gradient searching algorithm is able to preserve details. In this paper, we combine these two algorithms by using a weighting factor ${\alpha}$ to reflect the strong point of each algorithm effectively in the virtual view synthesis process. The experimental results show that the proposed algorithm performs much better than conventional algorithms.

• Spatial Information Research
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• v.16 no.3
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• pp.331-342
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• 2008

The countries are trying to expand the sea limit such as the territorial sea, fishing zone or the exclusive economic zone as far as the Law of the Sea permit to do for the benefit of their national interest. Especially, they are eager to claim the base point where it locates far from the coastline even if it is uninhabited island or reef under the sea. The baseline has been claimed to maximize the territorial sea. Another way to expand the sea limit is to lower the vertical datum to change the land limit. China claimed Dongdo which is located about 79 miles far from the coast as the base point. Japan also claimed many uninhabited island or the reef which is located very far from the coast such as Okino Dorishima. As Korea is the party who negotiate the maritime limit with Japan and China, we should be keen and sensitive on the issues claimed by neighboring countries in terms of base point and the baseline. This paper is to review the characteristics of the base points or baselines of neighboring countries and to suggest the views how to maintain and to relocate our base points. As western coast of Korean peninsula is one of the largest tide fluctuation zone in the world, with long tidal record to prove the vertical datum adjustment, Korea can find the way to lower the vertical datum especially in Yellow Sea. So, major and critical tidal station has to be set up along the western coast to verify tide fluctuation record which can be met with international standard.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.5
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• pp.577-588
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• 2011

This paper provides a novel extended Moving Least Squares(MLS) difference method for the potential problem with weak and strong discontinuities. The conventional MLS difference method is enhanced with jump functions such as step function, wedge function and scissors function to model discontinuities in the solution and the derivative fields. When discretizing the governing equations, additional unknowns are not yielded because the jump functions are decided from the known interface condition. The Poisson type PDE's are discretized by the difference equations constructed on nodes. The system of equations built up by assembling the difference equations are directly solved, which is very efficient. Numerical examples show the excellence of the proposed numerical method. The method is expected to be applied to various discontinuity related problems such as crack problem, moving boundary problem and interaction problems.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.155-156
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• 2003

90년대 이후 우리나라의 인구집중현상은 수도권에서 인근 소규모 도시까지 점차 확장된 택지개발 및 도로확장 정책을 생산하게 하였고 각종 부대 산업들의 발전을 이루게 되었다. 이러한 정책들은 수도권이라는 도시 집중현상을 가속화시키게 되었고 서울, 인천 및 부천 등에 국한되었던 집중 현상이 조금씩 확장되어 안산, 평택, 시흥 등 소규모 도시와의 경계가 모호할 정도로 가까워지고 있는 실정이다. 이러한 실정에서 국내에서는 유통마진을 최소화하여 소비자에게 저가의 상품을 제공하고자 하는 유통할인점들이 90년대 후반 이후 급격하게 증가하여 들어서기 시작하였다. (중략)

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.4
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• pp.563-571
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• 1999

변단 면과 다양한 경계조건을 갖는 보와 타워구조물의 제1모드에서의 고유진동수를 구하는 정확한 해는 1974년에 Kim에 의해 발표되었다. 최근 이 방법은 복합재료 적층 판을 포함하는 2차원 문제의 제 1모드 진동해석에 확장되었으며, 다양한 경계조건과 불규칙 단면을 갖는 판에 매우 효과적이다. 이 논문에서는 변단 면과 경계조건에 따른 특별직교 이방성 판에 대한, Kim에 의해 개발된 간편한 진동해석 방법의 응용결과가 주어진다. 또한 집중하중들에 대한 영향이 연구되었다.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.4
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• pp.114-122
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• 1995

In this paper a computational method is presented to solve the plane problem of wave propagation in linear-elastic plate with zones of different materials. An existing numerical scheme of bicharacteristics for rectangular plate is extended to plates with curvilinear boundaries. In order to show the validity of the employed concept, it is necessary to examine the numerical results whether they reproduce the well-known physical phenomena of stress waves. It seems also desirable to make a comparison between the numerical results and appropriate experimental results for plates with curvilinear boundaries. Also studied are the focusing phenomena induced by reflection and refraction at curved outer boundaries and material interfaces.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.1641-1644
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• 2004

3차원 볼륨데이터에서 분할 대상영역의 밝기 값이 다양하면서 밝기 값이 유사한 영역과 인접한 경우 3차원 영역확장(region growing) 방법을 사용하여 영역을 분할하기 위해서는 영역확장의 중요한 요인인 동질성 기준 값의 적절한 선택이 요구된다. 본 논문에서는 영역 복셀(voxel)의 1차 미분 값의 크기인 기울기 크기(gradient magnitude)만으로 영역의 경계를 찾기가 쉽지않은 대상의 분할을 위해 볼륨데이터의 지역적인 밝기 값의 변화의 특징을 고려하면서 분할 대상영역의 복셀의 2차 미분(second partial derivation)을 행렬의 요소(element)로 갖는 Hessian 행렬의 고유치(eigenvalue)를 영역확장의 문턱치 결정에 이용하였다. 제안한 알고리즘은 3차원 영역확장의 결과에 가장 큰 영향을 미치는 적절한 문턱치의 선택으로 대상영역의 분할을 성공적으로 수행하여 3차원 영역확장의 단점을 보완하였다.