• The KIPS Transactions:PartB
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• v.10B no.6
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• pp.657-664
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• 2003

Reliable tracking of moving humans is essential to motion estimation, video surveillance and human-computer interface. This paper presents a new approach to human motion tracking that combines appearance-based and model-based techniques. Monocular color video is processed at both pixel level and object level. At the pixel level, a Gaussian mixture model is used to train and classily individual pixel colors. At the object level, a 3D human body model projected on a 2D image plane is used to fit the image data. Our method does not use inverse kinematics due to the singularity problem. While many others use stochastic sampling for model-based motion tracking, our method is purely dependent on nonlinear programming. We convert the human motion tracking problem into a nonlinear programming problem. A cost function for parameter optimization is used to estimate the degree of the overlapping between the foreground input image silhouette and a projected 3D model body silhouette. The overlapping is computed using computational geometry by converting a set of pixels from the image domain to a polygon in the real projection plane domain. Our method is used to recognize various human motions. Motion tracking results from video sequences are very encouraging.

• Journal of the Earthquake Engineering Society of Korea
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• v.17 no.6
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• pp.257-269
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• 2013

In this study, the capability of an existing analysis method for the fluid-structure-soil interaction of an offshore wind turbine is expanded to account for the geometric nonlinearity and sea water drag force. The geometric stiffness is derived to take care of the large displacement due to the deformation of the tower structure and the rotation of the footing foundation utilizing linearized stability analysis theory. Linearizing the term in Morison's equation concerning the drag force, its effects are considered. The developed analysis method is applied to the earthquake response analysis of a 5 MW offshore wind turbine. Parameters which can influence dynamic behaviors of the system are identified and their significance are examined.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.2
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• pp.11-20
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• 1992

In general, the cross-section of a girder of a bridge has only one axis of symmetry. Therefore, lateral forces such as earthquake and wind may cause torsion coupled with lateral bending in the gider. This induces additional stresses especially in cables arranged in double-planes. Since this effect cannot be considered by using the conventional frame elements, the stiffness and the mass matrices of the geometrically nonlinear thin-walled frame element have to be used in order to model the girder. Theoretical development and verification of the frame element used in this study were made through a-previously presented paper. In this paper, seismic analysis of a three dimensional cable-stayed bridge considering the unsymmetry of the girder cross-section is performed to investigate the coupled flexural-torsional behaviors.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2002.06a
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• pp.392-407
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• 2002

컴퓨터의 발달은 정보의 축적, 처리, 분석과 전달능력을 기하급수적으로 증대 시키면서 사회전반의 효율성과 생산성을 획기적으로 향상시켰다. 그러나, 다른 한편으로는 이에 못지 않은 다양한 사회적 병리현상과 이와 관련된 윤리적 딜레마들을 양산하고 있다. 본 논문에서는 최근 정보사회로의 이행과정에서 제기되고 있는 정보통신 윤리상의 문제점 및 대응방안들을 검토하고, 그 중에서 자율적 규제방안의 하나인 윤리강령을 중심으로 다음과 같은 방법을 통해 향후 바람직한 컴퓨터 윤리 체계의 방향을 모색해 보았다. 첫째, 정보통신 윤리의 탄생 배경을 살펴보았다. 둘째, 현재 행해지고 있는 사회적, 제도적 대응 방안들과 그 현실적 한계점들을 검토하였다. 셋째, 그 중에서 자율적 규제방안의 하나인 윤리강령으로 논의의 범위를 좁혀서 현재 윤리강령들의 내용을 분석하고 바람직한 윤리강령의 조건들을 모색하였다. 끝으로 이상의 논의들을 토대로 향후 바람직한 윤리체계의 확립을 위한 종합적인 방안을 제시하였다. 본 논문은 정보통신망에서 벌어지고 있는 다양한 윤리적 문제점들을 극복하기 위해서 다각도로 모색되어야 할 대응방안들을 제시하였다. 또한, 본 논문은 단기적 차원의 법적 규제나 장기적 차원의 교육적 대응을 보완하면서, 동시에 자율적 합의에 의해 윤리적 원칙을 세워 갈 수 있는 윤리강령의 수립과 그 적극적 활용을 강조함으로써, 현재 우리나라의 컴퓨터 윤리 확립을 위한 구체적이고도 효과적인 대응방안을 제시하였다는데 의의가 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1175-1180
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• 2005

We present a vision-based hand gesture detection and tracking system. Most conventional hand gesture recognition systems utilize a simpler method for hand detection such as background subtractions with assumed static observation conditions and those methods are not robust against camera motions, illumination changes, and so on. Therefore, we propose a statistical method to recognize and detect hand regions in images using geometrical structures. Also, Our hand tracking system employs multiple cameras to reduce occlusion problems and non-synchronous multiple observations enhance system scalability. In this experiment, the proposed method has recognition rate of $99.28\%$ that shows more improved $3.91\%$ than the conventional appearance method.

• The KIPS Transactions:PartB
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• v.16B no.2
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• pp.109-116
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• 2009

In this thesis, an object tracking method based on the active feature model and the optical flow in stereo images is proposed. We acquired the translation information of object of interest and the features of object by utilizing the geometric information and depth of stereo images. Tracking performance is improved for the occlude object with this information by predicting the movement information of features of the occlude object. Rigid and non-rigid objects are experimented. From the result of experiment, the OOI can be real-time tracked from complicate back ground. Besides, we got the improved result of object tracking in any occlusion state, no matter what it is rigid or non-rigid object.

• The KIPS Transactions:PartB
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• v.15B no.6
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• pp.527-532
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• 2008

This paper proposes a novel approach to shadow detection from a single natural image regardless of orientation and type of light sources. This approach is based on the assumption that shadow brightness changes linearly, and the axiom that a region cast shadow on is darker than that not having shadow under the same environment. Firstly, candidates for shadow are extracted by preprocessing. Then, they are quantized to replace the similar values with a representative value because of the more quantization steps of a pixel brightness, the higher linear independency among the neighboring pixels. Finally, shadows are detected according to linear independency of shadow brightness based on the assumption. The experimental results showed the proposed approach can robustly detect umbra as well as self-shadow and penumbra cast on a single-colored background.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.2
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• pp.807-814
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• 2014

The purpose of this study is to analyze storytelling factors and mathematics contents of 'Eddy, the clever fox' on TV animation. The scenario and animation were analyzed according as criterion based on relevant materials. The results are as follows: First, Characters are 11 animals, Eddy is a problem solver. An ordinary story happens in the snow-covered woodland village. There is no story plot. And the story consists dialogue, song and narration. Second, mathematics contents in the animation appear in order number sense, geometry, measurement, data analysis and probability, pattern. So 'Eddy, the clever fox' is valuable as edutainment.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.330-333
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• 2011

TIP 기술은 2D 그림 또는 한 장의 사진으로부터 기하정보를 추출하여 3 차원 입체 효과를 만들어 영상 내부를 네비게이션할 수 있는 기술로써, 게임, 엔터테인먼트, 교육, 홍보 등 다양한 분야에서 요구되는 주요기술이다. 본 논문에서는 최근 대두되고 있는 스마트 device 의 platform 가운데 하나인 android platform 상에서의 OpenGL ES Library 를 이용한 TIP 기술 적용 및 구현 기술을 제안한다. 제안 방법은 전경객체의 추출이 어려운 상황을 감안하여 보다 사실적 장면 구성이 용이하도록 사용자의 선택에 의한 소실점을 이용하고, OpenGL ES Library 를 이용하여 3D 배경 모델을 획득하고, 이미지를 텍스쳐 매핑하여 3D 가상공간을 완성한 후 카메라의 시점 변환을 통해 이미지 내부를 네베게이션할 수 있도록 한다. 실험영상은 android platform 상의 device 에서 촬영한 이미지를 사용하고, android 2.1 및 OpenGL ES 1.0 기반으로 구축함으로써, 제안 기술을 다양한 android platform smart device 에서 적은 비용과 시간으로 응용 개발에 효과적으로 적용 가능하도록 구현하였다.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.43 no.4 s.310
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• pp.58-66
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• 2006

In this paper, we apply DCM(Dilation of Color and Motion information) mask and Active Contour Models(Snakes) to extract facial outline in moving pictures with complex background. First, we propose DCM mask which is made by applying morphology dilation and AND operation to combine facial color and motion information, and use this mask to detect facial region without complex background and to remove noise in image energy. Also, initial curves are automatically set according to rotational degree estimated with geometric ratio of facial elements to overcome the demerit of Active Contour Models which is sensitive to initial curves. And edge intensity and brightness are both used as image energy of snakes to extract contour at parts with weak edges. For experiments, we acquired total 480 frames with various head-poses of sixteen persons with both eyes shown by taking pictures in inner space and also by capturing broadcasting images. As a result, it showed that more elaborate facial contour is extracted at average processing time of 0.28 seconds when using interpolated initial curves according to facial rotation degree and using combined image energy of edge intensity and brightness.