• Journal of KIISE:Computer Systems and Theory
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• v.29 no.11
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• pp.589-600
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• 2002

Deformable models offer an attractive approach for extracting three-dimensional boundary structures from volumetric images. However, conventional deformable models have three major limitations - sensitive to initial condition, difficult to represent complex boundaries with severe object concavities and protrusions, and self-intersective between model elements. This paper proposes a deformable model that is effective to extract geometrically complex boundary surfaces by improving away the limitations of conventional deformable models. First, the proposed deformable model resamples its elements hierarchically based on volume image pyramid. The hierarchical resampling overcomes sensitivity to initialization by extracting the boundaries of objects in a multiscale scheme and enhances geometric flexibility to be well adapted to complex image features by refining and regularizing the size of model elements based on voxel size. Second, the physics-based formulation of our model integrates conventional internal and external forces, as well as a non-self-intersecting force. The non-self-intersecting force effectively prevents collision or crossing over between non-neighboring model elements by pushing each other apart if they are closer than a limited distance. We show that the proposed model successively extracts the complex boundaries including severe concavities and protrusions, neither depending on initial position nor causing self-intersection, through the experiments on several computer-generated volume images and brain MR volume images.

• Maritime Security
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• v.5 no.1
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• pp.113-136
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• 2022

China has been pushing for a systematic strategy for territorialization over a long period of time to invade Korea's West Sea (Yellow Sea) in order to create China's territorial water. China's strategy for territorializing the West Sea is an activity in which China curbs the use of South Korea and enforces the illegal use of China in order to dominate the West Sea exclusively. China aided Chinese fishing boats that engaged in illegal fishing in Korea's jurisdiction as a means to territorialize the West Sea, and is opposed to combined exercise and training of Korea and the United States Naval Forces in the West Sea, while intentionally entering KADIZ(Korea Air Defense Identification Zone). In addition, Beijing used 'scientific exploration and research' measures as a pretext for its strategies in order to encroach on Korea's West Sea. China is carrying out such work to announce to the world that China is a systematic and organized country while consistently attempting to dominate the West Sea. China's activities in the West Sea seriously infringe South Korea's sovereignty. In order to respond to China's strategies of territorialization in the West Sea stated above, I analyzed the rejection effect of the ROK-US combined military training in the West Sea and presented a 'proportional response strategy centered on the ROK-US combined forces'. Korea should be able to respond proportionally to China's activities in the seas around the Korean peninsula, and Korea should be able to neutralize China's attempt to a Fait Accompli. In addition, just as China installs buoys in the Korea-China Provisional Measures Zone, Korea should be able to install and actively utilize some devices in the West Sea and for the use of free and open West Sea. Korea should not just wait for the tragic future to come without preparing for China's gradual and long-term strategy, and Seoul needs to respond to China's maritime policy in the West Sea with a more active attitude than it is now. China has historically taken a bold and aggressive response to neighboring countries that are consistent with a passive attitude, on the other hand, Beijing has taken a cautious approach to neighboring countries that respond with an active attitude. It should not be forgotten that Korea's passive response to the Chinese strategy in the name of a 'realistic approach' such as Korea's economic dependence on China for economy will result in China's success for territorialization of the West Sea.