• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.364-370
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• 2002

본 논문에서는 양자물리학 분야에서 Lanczos 방법의 수렴을 가속화하기 위해 개발된 바 있는 행렬의 거듭제곱 기법을 동역학 분야의 Lanczos 순환식에 도입함으로써 구조물의 고유치 해석의 효율성을 향상시켰다 행렬의 거듭제곱 기법을 도입한 Lanczos 방법이 기존의 방법보다 수렴성이 더욱 우수하다. 수치예제를 통해 행렬의 거듭제곱 기법을 도입한 Lanczos 방법의 효율성을 검증하였으며 제안방법을 통한 고유치 해석에 있어서 가장 적합한 거듭제곱값을 제시하였다.

• Communications of Mathematical Education
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• v.20 no.4 s.28
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• pp.575-586
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• 2006

Both theory and experiment are very important parts in sciences. Especially in mathematics, theory seems to be very important, but experiment or practice doesn't. Numerical analysis of many parts in mathematics needs practice in computer. In this paper, I suggest that computer-practicing in teaching power method, inverse power method and deflation to calculate eigenvalues and eigenvectors is good in understanding the theory. It also makes students sure that mathematics is helpful.

• The Journal of Natural Sciences
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• v.16 no.1
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• pp.49-54
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• 2005

When teaching on the computing of eigenvalues of a matrix, we introduced the inverse power method. We compared the algorithm which is good for theoretical point of view that is useful for computational point of view.

• The KIPS Transactions:PartD
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• v.10D no.7
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• pp.1137-1144
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• 2003

The existing Function Point method to estimate the software size has been utilized frequently with the management information system. Due to the expanding usage of the real-time and embedded system, the Full Function Point method is being proposed. However, despite many research is being carried out relation to the software size, the research on the model to estimate the development cost from the measured software size is inadequate. This paper analyzed the linear regression model and power regression model which estimate the development cost from the software FFP The power model is selected, which shows its estimation is most adequate.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.553-561
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• 2015

The exponential and power law functionally graded material(FGM) theory is reformulated considering the refined shear and normal deformation theory. This theory has ability to capture the both normal deformation effect and exponential and power law function in terms of the volume fraction of the constituents for material properties through the plate thickness. Navier's method has been used to solve the governing equations for all edges simply supported plates on Pasternak elastic foundation. Numerical solutions of vibration analysis of FGM plates are presented using this theory to illustrate the effects of power law index and 3-D theory of exponential and power law function on natural frequency. The relations between 3-D and 2-D higher-order shear deformation theory are discussed by numerical results. Further, effects of (i) power law index, (ii) side-to-thickness ratio, and (iii) elastic foundation parameter on nondimensional natural frequency are studied. To validate the present solutions, the reference solutions are discussed.

• The Journal of the Korea Contents Association
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• v.10 no.8
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• pp.38-50
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• 2010

In recent years, the number of users who are actively express their opinions about Internet articles is more and more growing up, as the use of cyber community such as weblog or Internet discussion board increases. In fact, it is not difficult to find an article with hundreds of comments in famous Internet discussion boards. Most of the weblogs or Internet discussion boards present comments in the form of list and do not yet support even the basic operation such as searching comments. In this paper, we analysed large sets of comments in Internet discussion board named AGORA. It was found that from the result that the distribution of comment writers follows power-law. So we suppose a new search structure of comments using skip lists. The main idea of our approach is to reflect the probabilistic distribution properties of the commenters following the power-law to the data structure. Our empirical results show that the proposed method performs more efficient in searching the nodes with fewer number of comparison operations than logN, which is the theoretical time complexity of general indexed structure such as B-trees or typical skip lists.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.9-11
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• 1996

We apply a full mutigrid scheme to computing eigenvalues of the Laplace eigenvalue problem with Dirichlet boundary condition. We use finite difference method to get an algebraic equation and apply inverse power method to estimating the smallest eigenvalue. Our result shows that combined method of inverse power method and full multigrid scheme is very effective in calculating eigenvalue of the eigenvalue problem.

• Journal of the Korean Magnetics Society
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• v.19 no.5
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• pp.176-179
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• 2009

We report a direct observation of Barkhausen avalanches in 50-nm Fe film, using a magneto-optical microscope magnetometer, capable of time-resolved domain observation. The time-resolved domain-evolution patterns exhibit that the occurrence of Barkhausen jump is random with respect to interval, size, and location. From the repetitive measurements more than 1000 times, we found that the probability distribution of Barkhausen jump size follows a power-law distribution and the critical exponent reveals the value of 1.14 $\pm$ 0.03.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.11
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• pp.5930-5938
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• 2013

The sigmoid functionally graded mateiral(S-FGM) theory is reformulated using the nonlocal elatictiry of Erigen. The equation of equilibrium of the nonlocal elasticity are derived. This theory has ability to capture the both small scale effects and sigmoid function in terms of the volume fraction of the constituents for material properties through the plate thickness. Navier's method has been used to solve the governing equations for all edges simply supported boundary conditions. Numerical solutions of biaxial buckling of nano-scale plates are presented using this theory to illustrate the effects of nonlocal theory and power law index of sigmoid function on buckling load. The relations between nonlocal and local theories are discussed by numerical results. Further, effects of (i) power law index, (ii) length, (iii) nonlocal parameter, (iv) aspect ratio and (v) mode number on nondimensional biaxial buckling load are studied. To validate the present solutions, the reference solutions are discussed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.814-817
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• 2013

In this paper, we propose a visibility enhancement method using dehazing method in fog situation. The proposed method calculate low bound of the transmission rate that indicate fog rate and transmission that processed power operation in each pixel by the user's control. And we obtain the dehazed image using calculated transmission rate. Proposed method is possible real-time processing, because the method don't cause halo effect and drop operations from filtering by closed form. We can obtain the dehazed image in various fog conditions by user control that strength of removing fog can be adjusted according to the dgree of fog.