• Proceedings of the Korea Information Processing Society Conference
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• 2002.11a
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• pp.57-60
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• 2002

본 논문에서는 능동윤곽모델(active contour model)의 잘 알려져 있는 스네이크(snake) 알고리즘을 스테레오영상에 적용하여 좌 우 영상의 disparity 정보를 이용 객체의 경계선을 찾는 알고리즘을 제안한다. 스네이크는 객체의 경계를 얻기 위해 에지정보를 사용하는데 실제 이미지에서 객체의 경계가 아닌 인접한 주위의 강한 애지(edge)에 대해서도 영향을 받게 되는 문제가 있다. 이러한 문제를 해결하기 위해 스테레오영상의 disparity 정보를 이용하여 이를 개선하고 disparity 측정에 사용되는 블록매칭(block matching)방법을 스네이크 알고리즘에 적용시켰다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.8
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• pp.3654-3659
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• 2012

Active contour model or snake is widely used for segmentation method in the area of the image processing and computer vision. The main problem in the active contour model is that results are very dependent to the closet points of the numbers and the location in initial step. Especially, in case of balloon-like active contour model, the small region which consist of intial closet points are expanded until the edge is reached. It is a serious problem because the considered region are huge with limited points. To solve this problem, in this paper, we propose the method that the number of closet points could be change based on the distance between points.

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.17-28
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• 2010

Since a homing torpedo system consists of various subsystems, organic interactions of which dictate the performance of the torpedo system, it is necessary to estimate the effects of individual subsystems in order to obtain an optimized design of the overall system. This paper attempts to gain some insight into the detection mechanism of a torpedo run, and analyze the relative importance of various parameters of a torpedo system. A database for the analysis was generated using a simulation model based on the combined discrete event and discrete time architecture. Multiple search schemes, including the snake-search method, were applied to the torpedo model, and some parameters of the torpedo were found to be stochastic. We then analyzed the effectiveness of torpedo’s detection capability according to the torpedo speed, the target speed, and the maximum detection range.

• Korean Journal of Environment and Ecology
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• v.30 no.2
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• pp.173-184
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• 2016

Knowledge of the relationships among interspecific competition, spatial distributions and ecological niches plays an important role in understanding biogeographical distribution patterns of species. In this study, the distributional characteristics and ecological niches of the three Viperidae species (Gloydius ussuriensis, G. brevicaudus, and G. saxatilis) in South Korea were determined based on observation data and species distribution model. The effects of interspecific competition on geographical distribution and the division of the ecological niches of the vipers were also examined based on the models of predicted species distribution. The results showed that altitude was the most important environmental variable for their distribution, and the altitudes at which these snakes were distributed correlated with the climate of that region. Although interspecific ecological niches are quite overlapped, their predicted distribution patternsvary by the Taebaek Mountains. When overlaying the distribution models, most of the overlapping habitats were forest areas, which were relatively less overlapped than were the entire research areas. Thus, a parapatric distribution pattern was expected. The abundance of species occurring sympatrically was positively correlated with each other, indicating the lack of serious interspecies competition in this region. In conclusion, although the three Viperidae species in South Korea occupy similar ecological niches, these snakes exhibit parapatric distribution patterns without direct competition. Further research on various geographic variables (e.g., altitude, microhabitat characteristics) using relatively fine grid sizes, as well as further detailed ecological and behavioral research, is needed to determine the causative factors for the parapatric distribution pattern.

• Journal of the Korea Society of Computer and Information
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• v.17 no.8
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• pp.31-40
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• 2012

In this paper, we propose a method of synthesizing faces of a user and an animation character using a 3D face model. The suggested method first receives two orthogonal 2D face images and extracts major features of the face through the template snake. It then generates a user-customized 3D face model by adjusting a generalized face model using the extracted facial features and by mapping texture maps obtained from two input images to the 3D face model. Finally, it generates a user-customized animation character by synthesizing the generated 3D model to an animation character reflecting the position, size, facial expressions, and rotational information of the character. Experimental results show some results to verify the performance of the suggested algorithm. We expect that our method will be useful to various applications such as games and animation movies.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.266-274
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• 2009

An abdominal aortic aneurysm occurs most commonly in older individuals (between 65 and 75), and more in men and smokers. The most important complication of an abdominal aortic aneurysm is rupture, which is most often a fatal event. An abdominal aortic aneurysm weakens the walls of the blood vessel, leaving it vulnerable to bursting open, or rupturing, and spilling large amounts of blood into the abdominal cavity. surface modeling is very useful to surgery for quantitative analysis of abdominal aortic aneurysm. the 3D representation and surface modeling an abdominal aortic aneurysm structure taken from Multi Detector Computed Tomography. The construction of the 3D model is generally carried out by staking the contours obtained from 2D segmentation of each CT slice, so the quality of the 3D model strongly defends on the precision of segmentation process. In this work we present deformable model algorithm. deformable model is an energy-minimizing spline guided by external constraint force. External force which we call Gradient Vector Flow, is computed as a diffusion of a gradient vectors of gray level or binary edge map derived from the image. Finally, we have used snakes successfully for abdominal aortic aneurysm segmentation the performance of snake was visually and quantitatively validated by experts.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06b
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• pp.279-282
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• 2010

최근 단일 고해상도 위성영상과 건물과 지형에 대한 정보를 가지고 있는 수치지도(DEM:Digital Elevation Model)를 이용하여 3차원 영상으로 구축하는 연구가 많이 이루어지고 있다. 3차원영상을 구축하기 위해서는 건물과 지형의 위치, 크기, 형상에 관한 정보가 필요하나 위성영상만으로는 구하기가 어려워 수치지도를 활용한다. 본 논문에서는 수치지도를 이용하여 3차원 건물과 지형의 고도 정보를 추출하고, 위성영상과 Snake 모델을 이용하여 반자동으로 추가적인 건물 높이와 바닥면에 대한 정보를 추출하여, 3차원 영상을 생성 하는 방법을 제안한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.11a
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• pp.103-105
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• 2022

본 논문에서는 스네이크 알고리즘에서 복잡한 배경으로 인해 어긋난 윤곽선을 개선하는 방법을 제안한다. 스네이크 알고리즘은 능동 윤곽선 모델(active contour model)중 하나로, 사전 정의한 영역에서 시작하여 점진적으로 강한 변화가 감지되는 방향으로 윤곽선을 수정하는 방법이다. 그러나 이러한 방법은 강한 기울기 성분이 나타나는 배경에 취약하고, 대상의 불필요한 영역이 포함되거나, 필요한 영역이 포함되지 않는 문제가 발생한다. 제안하는 방법은 이미지에 원근 변환을 기반으로 한 스네이크 알고리즘을 반복적으로 적용하여 대상의 윤곽선을 온전히 추출한다. 이는 실험 데이터에서 평균 IoU가 약 11.5% 이상 증가한 것을 통해 올바른 윤곽선을 찾는데 효과적인 방법임을 알 수 있다.

• Journal of the Korea Society for Simulation
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• v.18 no.2
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• pp.77-89
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• 2009

Visual tracking technique is one of the essential things which are very important in the major fields of modern society. While contour tracking is especially necessary technique in the aspect of its fast performance with target's external contour information, it sometimes fails to track target motion because it is affected by the surrounding edges around target and weak egdes on the target boundary. To overcome these weak points, in this research it is suggested that PDMs can be obtained by generating the virtual 6-DOF motions of the mobile robot with a CCD camera and the image tracking system which is robust to the local minima around the target can be configured by constructing Active Shape Model in modular base. To show the effectiveness of the proposed method, the experiment is performed on the image stream obtained by a real mobile robot and the better performance is confirmed by comparing the experimental results with the ones of other major tracking techniques.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.6
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• pp.464-468
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• 2009

In this paper we propose an image-based approach, which is different from the traditional flow cytometric method to detect shape of apoptosis cells. This method can overcome the defects of cytometry and give precise recognition of apoptosis cells. In this work K-means clustering was used to do the rough segmentation and an active contour model, called 'snake' was used to do the precise edge detection. And then some features were extracted including physical feature, shape descriptor and texture features of the apoptosis cells. Finally a Mahalanobis distance classifier classifies the segmentation images as apoptosis and non-apoptosis cell.