• 대한수학회지
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• 제50권2호
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• pp.445-464
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• 2013

We describe the one-dimensional and zero-dimensional cusps of the Satake compactification for the paramodular groups in degree two for arbitrary levels. We determine the crossings of the one-dimensional cusps. Applications to computing the dimensions of Siegel modular forms are given.

• 한국전자통신학회논문지
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• 제16권3호
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• pp.533-540
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• 2021

시스템의 성능을 평가하기 위하여 1차원 3-이웃 셀룰라 오토마타(Cellular Automata, 이하 CA) 기반의 의사 난수 생성기가 여러 분야에서 많이 응용되고 있다. 보다 더 효과적인 키 수열 생성을 위해 2차원 CA와 1차원 5-이웃 CA가 응용되었으나, 주어진 특성 다항식에 대응하는 대칭 1차원 5-이웃 CA를 설계하는 것은 매우 어려운 문제이다. 이를 해결하기 위해 특성 다항식의 점화식을 이용한 합성 방법, Krylov 행렬을 이용한 합성 방법과 같이 1차원 5-이웃 CA 합성에 관한 연구들이 진행되었다. 그러나 여전히 비선형 방정식을 풀어야 하는 문제점이 있었다. 이러한 문제점을 해결하기 위해, 최근 90/150 CA의 전이 행렬과 블록행렬을 이용한 1차원 5-이웃 CA 합성 방법이 제안되었다. 본 논문에서는 제안된 알고리즘의 이론적인 과정을 상세히 기술하고 그 알고리즘을 이용하여 높은 차수의 원시 다항식에 대응하는 대칭 1차원 5-이웃 CA를 구한다.

• 한국재료학회지
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• 제33권7호
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• pp.279-284
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• 2023

One-dimensional MgO nanostructures with various morphologies were synthesized by a thermal evaporation method. The synthesis process was carried out in air at atmospheric pressure, which made the process very simple. A mixed powder of magnesium and active carbon was used as the source powder. The morphologies of the MgO nanostructures were changed by varying the growth temperature. When the growth temperature was 700 ℃, untapered nanowires with smooth surfaces were grown. As the temperature increased to 850 ℃, 1,000 ℃ and 1,100 ℃, tapered nanobelts, tapered nanowires and then knotted nanowires were sequentially observed. X-ray diffraction analysis revealed that the MgO nanostructures had a cubic crystallographic structure. Energy dispersive X-ray analysis showed that the nanostructures were composed of Mg and O elements, indicating high purity MgO nanostructures. Fourier transform infrared spectra peaks showed the characteristic absorption of MgO. No catalyst particles were observed at the tips of the one-dimensional nanostructures, which suggested that the one-dimensional nanostructures were grown in a vapor-solid growth mechanism.

• 대한기계학회논문집
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• 제19권4호
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• pp.1041-1050
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• 1995

The deformed shape of rod specimen of copper alloys was measured after the high-velocity impact against a rigid anvil and analyzed with one-dimensional theory to determine dynamic yield stress and strain-rate sensitivity which is defined as the ratio of dynamic yield stress to static flow stress. The evvect of two-dimensional deformation on the determination of dynamic yield stress by the one-dimensional theory, was investigated through comparison with the analysis by hydrocode. It showed that the one-dimensional theory is relatively consistent with two-dimensional hydrocode in spite of its simplicity in analysis.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.227-231
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• 2001

Analysis of two-dimensional unsteady flows with a free surface in a rectangular container subject to a linear reciprocating force is performed by numerical and experimental methods. FVM is used for the numerical computation of the two-dimensional flows. We consider the surface tension as well as the viscous/elastic properties of the free surface. One-dimensional analysis as well as experiment is used in establishing the free surface properties. The steady recirculatory flow is visualized by a laser sheet. It is shown that the one-dimensional analysis provides useful informations associated with the free surface properties.

• Journal of electromagnetic engineering and science
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• 제9권4호
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• pp.211-217
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• 2009

A three-dimensional locally one-dimensional multiresolution time-domain(LOD-MRTD) method is introduced and unconditional stability is proved analytically. The updating formulations have fewer terms on the right-hand side than those of an alternating direction implicit MRTD(ADI-MRTD). The validation of the method is presented using the resonance frequency problem of an empty cavity. The reduction of the numerical dispersion technique is also combined with the proposed method. The numerical examples show that the combined method can improve the accuracy significantly.

• Journal of applied mathematics & informatics
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• 제29권1_2호
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• pp.161-171
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• 2011

The convergence rate of a numerical procedure based on Schwarz Alternating Method(SAM) for solving elliptic boundary value problems depends on the selection of the interface conditions applied on the interior boundaries of the overlapping subdomains. It has been observed that the Robin condition (mixed interface condition), controlled by a parameter, can optimize SAM's convergence rate. In [7], one had formulated the multi-parameterized SAM and determined the optimal values of the multi-parameters to produce the best convergence rate for one-dimensional elliptic boundary value problems. However it was not successful for two-dimensional problem. In this paper, we present a new method which utilizes the one-dimensional result to get the optimal convergence rate for the two-dimensional problem.

• 설비공학논문집
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• 제11권5호
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• pp.579-587
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• 1999

The flow distribution characteristics in a complex duct system have been investigated in this paper by three means, namely experimental measurement, numerical simulation and the Extended T-method analysis. While the exit flow rates predicted by the three-dimensional CFD calculation and those given by the experiment show a close agreement, the results from the one-dimensional Extended T-method are found to differ from the experiment by -22.2% to 26.3% for the various exits. These discrepancies may be attributed to the underlying limitation concerning the fitting loss coefficients, which assume that the flow in front of the fittings is fully developed. It is proposed that, in order to analyse the three-dimensional flow distributions in a complex duct system by one-dimensional analysis such as the Extended T-method, further Improvements to the fitting loss coefficients should be made.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제9권2호
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• pp.55-64
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• 2005

In this paper, generalized difference methods(GDM) for one-dimensional viscoelastic problems are proposed and analyzed. The new initial values are given in the generalized difference scheme, so we obtain optimal error estimates in $L^p$ and $W^{1,p}(2\;{\leq}\;p\;{\leq}\;{\infty})$ as well as some superconvergence estimates in $W^{1,p}(2\;{\leq}\;p\;{\leq}\;{\infty})$ between the GDM solution and the generalized Ritz-Volterra projection of the exact solution.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.136-141
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• 2001

In this study, we analysed tree surface flow by using the experimental and numerical method with a different surfactant concentration. We compared numerical solution with experimental results for one-dimensional model. The result shows that in general the tree surface velocity can well be reproduced by the one-dimensional model for various surfactant concentration.