• International Journal of Internet, Broadcasting and Communication
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• 제11권1호
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• pp.39-46
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• 2019

This paper proposes an adaptive threshold watershed algorithm, which is the method used for image segmentation and boundary detection, which extends the region on the basis of regional minimum point. First, apply adaptive thresholds to determine regional minimum points. Second, it extends the region by applying adaptive thresholds based on determined regional minimum points. Traditional watershed algorithms create over-segmentation, resulting in the disadvantages of breaking boundaries between regions. These segmentation results mainly from the boundary of the object, creating an inaccurate region. To solve these problems, this paper applies an improved watershed algorithm applied with adaptive threshold in regional minimum point search and region expansion in order to reduce over-segmentation and breaking the boundary of region. This resulted in over-segmentation suppression and the result of having the boundary of precisely divided regions. The experimental results show that the proposed algorithm can apply adaptive thresholds to reduce the number of segmented regions and see that the segmented boundary parts are correct.

• 지역연구
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• 제12권2호
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• pp.37-57
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• 1996

Intra-metropolitan spatial segmentation of the labor marker requires barriers of mobility on both supply and demand side of the local labor marker. The phenomena of spatial segmentation of the labor market are particularly applied to the secondary workers rather than to the primary workers. Supply side barriers include the costs of obtaining job information regarding jobs outside of the immediate area, commuting costs, and barriers to residential mobility. Demand side barriers include site-specific technology and product demand, and discrimination. In this paper, I discuss these barriers and examine their implications for differences in segmentation by demographic and skill groups at the intra-metropolitan scale. In particular, I apply a job search model to examine supply side barriers such as information and commuting costs, and an implicit contract model to explain demand side barriers such as dual/internal labor market and firms' (re) location strategies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권1호
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• pp.211-230
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• 2022

In image segmentation, for the condition that objects (targets) and background in an image are intertwined or their common boundaries are vague as well as their textures are similar, and the targets in images are greatly variable, the deep learning might be difficult to use. Hence, a new method based on graph theory and guided feathering is proposed. First, it uses a guided feathering algorithm to initially separate the objects from background roughly, then, the image is separated into two different images: foreground image and background image, subsequently, the two images are segmented accurately by using the improved graph-based algorithm respectively, and finally, the two segmented images are merged together as the final segmentation result. For the graph-based new algorithm, it is improved based on MST in three main aspects: (1) the differences between the functions of intra-regional and inter-regional; (2) the function of edge weight; and (3) re-merge mechanism after segmentation in graph mapping. Compared to the traditional algorithms such as region merging, ordinary MST and thresholding, the studied algorithm has the better segmentation accuracy and effect, therefore it has the significant superiority.

• 한국통신학회논문지
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• 제22권3호
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• pp.432-443
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• 1997

This paper presents contour simplification method and a regional hierarchical segmentation algorithm based on PSNR for the transmission of image in mobile communication, of which available bandwidth is very limited. It first takes into account the global information and produces a coarse segmentation, that is, with a small number of regions. Then, each segmented region has different quality. Thus, the region with low quality is selected by PSNR and improved by introducing regions corresponding to more local information. It is able to improve the subjective quality of image and reduce contour information. In addition, contour simplification method is proposed for the efficient lossless chain coding. The proposed method can be applied to the applications such as mobile communications and videotelephone through PSTN, of which the available transmission bandwidth is very limited.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1323-1325
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• 2003

As to many conventional segmentation approaches , spatial autocorrelation, perhaps being the first law of geography, is always overlooked. Thus, the corresponding segmentation results are always not so satisfying, which will further affect the subsequent image processing or analyses. In order to improve segmentation results, a geostatistic based segmentation approach with the consideration of spatial autocorrelation hidden in remote-sensing images is proposed in this article. First, by calculating the mean variance between each pair of pixels at given different lag distances, information like the size of typical targets in the scene can be obtained, and segmentation thresholds are calculated accordingly. Second, an initial region growing segmentation approach is implemented. Finally, based on the segmentation thresholds obtained at the first step and the initial segmentation results, the final segmentation results are obtained using the same region growing approach by taking the local mutual best fitting strategy. From the experiment results, we found the approach is rather promising. However, there still exists some problems to be settled, and further researches should be conducted in the future.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.4641-4650
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• 2015

본 연구는 지방의료원의 고객세분화를 통하여 향후 전문화된 의료기관으로 진료전문성을 강화하여 경쟁력을 확보할 수 있는 진료전문화 전략을 제시하는데 목적이 있다. 조사기간은 2013년 1월부터 12월까지 입원한 환자 26,658명을 연구대상을 선정하였다. 분석방법은 군집분석과 의사결정나무분석을 이용하였다. 결론을 보면, 성별은 여자, 연령은 60세 이상, 질환별로는 근 골격계 및 결합조직의 질환이 충성고객으로 선정되었다. 이들은 지방의료원의 고객관리측면에서 향후 구전의 효과가 높은 고객 군으로 금전적인 소비규모가 높은 점을 고려하여 이들에게 제공된 의료서비스에 대한 모니터링과 커뮤니케이션을 통해 지속적인 관계를 유지하는 것이 중요하다. 앞으로 전문 분야의 전문의와 전문적 시설 확보 등의 적합한 조직구조와 환경을 갖추는 것이 중요하며, 지역 내 개원의, 유관기관간의 전략적 제휴 통한 진료협력 및 의뢰, 의료서비스 범위의 집중화가 필요하다.

• 전기학회논문지
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• 제59권1호
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• pp.210-216
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• 2010

In this study, we propose a novel method to segment an individual tooth region in a true color image. The difference of the intensity in RGB is initially extracted and subsequent morphological reconstruction is applied to minimize the spurious segmentation regions. Multiple seeds in the tooth regions are chosen by searching regional minima and a Sobel-mask edge operations is performed to apply MCWA(Marker-Controlled Watershed Algorithm). As the results of applying MCWA transform for our proposed tooth segmentation algorithm, the individual tooth region can be resolved in a CCD tooth color image.

• 전기학회논문지
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• 제59권6호
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• pp.1136-1142
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• 2010

In this study, an efficient removal algorithm for specular reflections in a tooth color image is proposed to minimize the artefact interrupting color image segmentation. The pixel values of RGB color channels are initially reversed to emphasize the features in reflective regions, and then those regions are automatically detected by utilizing perceptron artificial neural network model and those prominent intensities are corrected by applying a smoothing spatial filter. After correcting specular reflection regions, multiple seeds in the tooth candidates are selected to find the regional minima and MCWA(Marker-Controlled Watershed Algorithm) is applied to delineate the individual tooth region in a CCD tooth color image. Therefore, the accuracy in segmentation for separating tooth regions can be drastically improved with removing specular reflections due to the illumination effect.

• 재무관리연구
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• 제15권2호
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• pp.401-419
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• 1998

This paper examines the international arbitrage pricing model (IAPM) in regional equity markets setting. Factor analyses are used to estimate the international common risk factors. And the cross-sectional regression analyses are used to test the validity of regional IAPMs and Chow tests are used to evaluate the integration of regional equity markets. The results of factor analyses show that the number of common factors in each regional group is seven. The cross-sectional regression results lead us not to reject that the IAPMs are regionally valid but Chow test results lead us to reject that regional equity markets are integrated.

• 대한원격탐사학회지
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• 제22권6호
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• pp.601-612
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• 2006

본 연구는 방대한 크기 원격 탐사 영상 자료의 효율적인 분석을 위한 RAG (Region Adjancency Graph) 기반 영상 분할 기법을 제안하고 있다. 제안된 알고리즘은 계산의 효율성을 위하여 CN-chain 연결과 저장 기억의 효율성을 위하여 sliding 다중 창을 사용한다. RAG에 의한 지역 합병은 최선의 결합을 위한 edge을 발견과 합병에 따른 graph의 갱신의 과정이다. CN-chain 연결법은 가장 유사한 인접 지역의 연결을 형성하면서 최선의 edge를 발견하여 합병을 해 나가는 과정으로 영상 자료 크기의 증가에 따라 단지 증가 배수만큼만 분석 시간을 증가시킨다. 합병에 의해 변하는 RAG의 효율적인 갱신을 위하여 RNV(Regional Neighbor Vector)를 사용하였다. 방대한 크기 자료 분석은 막대한 기억 용량의 시스템을 필요로 한다. 제안된 수평적인 구조의 sliding 다중 창 작업은 필요한 기억 용량을 현저히 감소시켜 가능한 분석 자료의 크기를 증대시켰을 뿐 아니라 계산 시간의 감소를 초래하였다. 본 연구는 simulation 자료를 사용하여 광범위하게 제안된 알고리즘의 성능을 실험하였으며 실험 결과는 알고리즘의 효율성을 입증하였다.