• Tunnel and Underground Space
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• v.29 no.4
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• pp.262-279
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• 2019

In the engineering barriers of high-level radioactive waste disposal, gases could be generated through a number of processes. If the gas production rate exceeds the gas diffusion rate, the pressure of the gas increases and gases could migrate through the bentonite buffer. Because people and the environment can be exposed to radioactivity, it is very important to clarify gas migration in terms of long-term integrity of the engineered barrier system. In particular, it is necessary to identify the hydro-mechanical mechanism for the dilation flow, which is a very important gas flow phenomenon only in medium containing large amounts of clay materials such as bentonite buffer, and to develop and validate new numerical approach for the quantitative evaluation of the gas migration phenomenon. Therefore, in this study, we developed a two-phase flow model considering the mechanical damage model in order to simulate the gas migration in the engineered barrier system, and validated with 1D gas flow modelling through saturated bentonite under constant volume boundary conditions. As a result of numerical analysis, the rapid increase in pore water pressure, stress, and gas outflow could be simulated when the dilation flow was occurred.

• Proceedings of the IEEK Conference
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• 2000.11d
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• pp.45-48
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• 2000

In this paper, we propose a region-based segmentation algorithm to extract human face area using a window function and neural networks. Furthermore, we apply the erosion and dilation to remove small error areas. By applying the window function, it is possible to reduce error. In particular, false segmentation of the eye and the lip can be considerably reduced. Experiments show promising results and it is expected that the Proposed method can be applied to video conference and still image compression.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.479-482
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• 1998

Whether a given tree is a subgraph of the interconnection network topology is one of the important problem in parallel computing. Trees are used as the underlying structure for divide and conquer algorithms and provide the solution spaces for NP-complete problems. Complete binary trees are the basic structure among those trees. Binomial trees play an important role in broadcasting messages in parallel networks. If binomial trees can be efficiently embedded in complex binary trees, broadcasting algorithms can be effeciently performed on the interconnection networks. In this paper, we present average dilation 2 embedding of binomial trees in complete binary trees.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.5
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• pp.118-126
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• 1996

In object analysis by image processing, finding lines plays a universal role. And these lines can be easily found by detecting ridges and valleys in digital gray scale images. In this paper, a new method of detecting ridges and valleys by using local min/max operations was presented. This method detects ridges and valleys of desired width by using erosion and dilation properties of local min/max operations, and requires no information of ridge or valley direction. Therefore the method is efficient and computationally simple in comparision with the conventional analytical method.

• Communications of the Korean Mathematical Society
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• v.11 no.4
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• pp.967-974
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• 1996

We discuss contraction operators T in the class A, where A is the class of absolutely continuus contractions for which the Sz.-Nagy-Foias functional calculus is isometry. We obtain relationship between the class $A_{n, \aleph_0}$ and hereditary property $(\tilde{P}_n)$.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.289-292
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• 1998

Trees are the underlying structure for divide-and-conquer algorithms and the graphs that provide the solution spaces for NP-complete problems. Complete binary trees are the basic structure among trees. Therefore, if complete binary trees can be embedded in binomial trees, the algorithms which are provided by complete binary trees can be performed efficiently on the interconnection networks which have binomial trees as their subgraphs or in which binomial trees can be embedded easily. In this paper, we present dilation 2 embedding of complete binary trees in binomial trees.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.6
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• pp.899-908
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• 1995

In this paper, the probabilistic relations of dual morphological operations, such as dilation and erosion, closing and opening, and close- open and open-close, and the statistical properties for a continuous stationary lst order Gauss-Markov source are analyzed. The result is that the dual filters have symmetrical means and skews, and equal variances. Also, the statistics of morphological filters are very similar with those of input source, as correlation coefficient increases.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.2
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• pp.111-117
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• 1996

In tis paper, a new morphological algorihtm for binary image reconstruction from graayscale skeleton is proposed. In the proposed algorithm, grayscale morphological dilation is utilizedm instead of binary morphological operatons for the conventional methods. The algorithm is proven mathematically and verified by computer simulation results.

• Journal of Environmental Health Sciences
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• v.13 no.1
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• pp.41-46
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• 1987

The purpose of this experiment was to investigate the leisons of mice produced by intraperitoneal injection of rubratoxin B. But the mice injected 3$\mu$g and 5$\mu$g of rubratoxin B showed retardation of growth, and slight swelling of kidneys. The hemorrhage in the renal cortex tubular dilation containing the desquamated epithelial cells, and adhesion of Bowman's spaces by proliferation of endothelial cells were histopathoglogically characterized in the kidneys of mice.

• Journal of applied mathematics & informatics
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• v.13 no.1_2
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• pp.393-404
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• 2003

In general, a differential operator can be used as a tool of treating the local properties of given function. However, when the given function is varied with high frequency and has irregular form with non-stationary evolution it may not act its role sufficiently as in case of nowhere differentiable curves. In this paper we introduce a multi-scale derivative as a form of weakened global derivative so that it may explain its semi global diffusion properties as well as local ones for the various irregular diffusion phenomena.