• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.439-442
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• 2008

Diffraction of multi-directional random waves passing semi-infinite breakwater is investigated by using analytic solution derived by Penny and Prices(1952). An irregylarity of period and incident angle of waves and regular periods for regular waves are considered in addition by expanding from the past study which used only monochromatic wave in general. The Bretschneider-Mitsuyasu frequency spectrum and Mitsuyasu directional spectrum are used for incident waves. And diffraction of multi-directional random waves is reappeared by decomposing numerical results of several monochromatic waves which have variable period and incident angle. Analytic solution on the diffraction of regular waves and multi-directional random waves calculated in this study.

• East Asian mathematical journal
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• 제33권1호
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• pp.1-9
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• 2017

In [8] they introduced a new finite element method for accurate numerical solutions of Poisson equations with corner singularities, which is useful for the problem with known stress intensity factor. They consider the Poisson equations with homogeneous Dirichlet boundary condition, compute the finite element solution using standard FEM and use the extraction formula to compute the stress intensity factor, then they pose a PDE with a regular solution by imposing the nonhomogeneous boundary condition using the computed stress intensity factor, which converges with optimal speed. From the solution they could get accurate solution just by adding the singular part. This approach works for the case when we have the reasonably accurate stress intensity factor. In this paper we consider Poisson equations defined on a domain with a concave corner with Neumann boundary conditions. First we compute the stress intensity factor using the extraction formular, then find the regular part of the solution and the solution.

• 충청수학회지
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• 제24권1호
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• pp.45-57
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• 2011

We study the stochastic integral of an operator valued process against with a Banach space valued regular process. We establish the existence and uniqueness of solution of the stochastic differential equation for a Banach space valued regular process under the certain conditions. As an application of it, we study a noncommutative stochastic differential equation.

• 한국수학사학회지
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• 제14권1호
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• pp.17-26
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• 2001

Ri, Sang-Hyeok(1810-\ulcorner) explained in detail and repeatedly solution of problems which find the area and diameter of inscribed and circumscribed circles of regular polygons from a side and find a side of regular polygons from the area of the book Su-Ri-Jeong-On in the chapter ‘Gak-Deung-Byeon-Hyeong-Seup-Yu’ of his book San-Sul-Gwan-Kyeun. The explanation of each question describes the procedure to make the equation in detail, but only presents the solution with few step to solve.

• 산업융합연구
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• 제19권4호
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• pp.23-28
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• 2021

본 논문은 미해결 문제로 알려진 36 장교문제(n = 6)와 관련된 오일러 방진 퍼즐 게임 문제에 대해 n = [3, ∞]의 문제를 풀 수 있는 일정한 패턴 규칙을 찾고자 시도하였다. 이 문제의 해는 현재까지 [3, 10]에 대해 n = 6만 존재하지 않고 나머지 모든 숫자에 대한 해는 존재하는 것으로 알려져 있다. 또한, 기존 연구는 특정 숫자 n에 대해 컴퓨터 프로그램으로 랜덤한 배정 결과를 찾고자 하여 n = [11, ∞]에 대해서는 해를 찾기가 쉽지 않아 미해결 과제로 남아있다. 기존 연구는 n = [3, 10]으로 한정시킨 반면에, 본 논문은 n = [3, ∞]영역에서 어떠한 n의 값에 대해서도 해를 찾을 수 있는 일반화된 패턴을 찾고자 시도하였다. 본 논문에서는 n = odd, 4k even, 4k+2 even의 세 부분으로 분할하여 n = odd와 4k even(n/2 = even)에 대한 간단하면서도 일정한 패턴을 찾는데 성공하였다. 그러나 4k+2 even(n/2 = odd)에 대해서는 패턴을 찾지 못하였다.

• Journal of applied mathematics & informatics
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• 제18권1_2호
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• pp.145-158
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• 2005

We formulate a stochastic control problem on proportional reinsurance that includes impulse and regular control strategies. For the first time we combine impulse control with regular control, and derive the expected total discount pay-out (return function) from present to bankruptcy. By relying on both stochastic calculus and the classical theory of impulse and regular controls, we state a set of sufficient conditions for its solution in terms of optimal return function. Moreover, we also derive its explicit form and corresponding impulse and regular control strategies.

• 한국표면공학회지
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• 제29권4호
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• pp.253-260
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• 1996

Regular spangle hot dip galvanized steel sheets were made in the zinc bath containing a small amount of Al and with the addition of Pb, Sb, Sb-Mg, Sb-Cu and Bi respectively whose average glosses were measured. Zero-spangle hot dip galvanized steel sheets were also made by spraying a 2% $NH_4H_2PO_4$ solution on molten coating surfaces with exactly the same chemical compositions as above used for regular spangle and whose glosses and corrosion losses were also evaluated. For manufacturing zero- spangle hot dip galvanized steel sheets with high brightness, the zinc bath with 0.02%Sb and the spraying of a 2% $NH_4H_2PO_4$ solution were proposed and for better brightness and corrosion resistance, the zinc bath with 0.02% Sb-0.50%Mg and the spraying of a 2% $NH_4H_2PO_4$ solution were also proposed.

• 한국응용과학기술학회지
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• 제18권4호
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• pp.249-253
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• 2001

A proposed method of determining the composition of mixed micelles in equilibrium with monomer of known composition is described. The systems were sodium ${\alpha}-sulfonated$ dodecanoyl ethyl esther (${\alpha}-SR_{12}Et$) or sodium dodecyl sulfate(SDS)-polyoxyethylene 23 lauryl ether (Brij 35) un water and in 0.1M sodium chloride solution at $25^{\circ}C$. This technique applies the Gibbs-Duhem equation to the mixed micelles, which is treated as a pseudophase. This proposed methodology, which needs only critical micelle concentration data as a function of monomer composition, is applied to an anionic/nonionic surfactant pair. The calculated monomer-micelle equilibrium is found to be very similar to the much-used regular solution for nonideal systems.

• 대한간호학회지
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• 제44권1호
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• pp.13-20
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• 2014

Purpose: This study was done to examine the effects of 4% hypertonic saline solution mouthwash and tooth brushing education on the oral health of elders living in long term care facilities. Methods: In this quasi-experimental study, the participants were assigned to a 2% experimental group (n=20), a 4% experimental group (n=20), and a control group (n=20). Data were analyzed using ANOVA, repeated measures ANOVA, Fisher exact test, Chi-square test, Kruskal-Wallis test and multiple response analysis with the SAS program. Results: Regular tooth brushing and use of 4% hypertonic saline solution mouthwash by elders provided better oral health by decreasing xerostomia, oral tongue plaque, halitosis, and the number of oral bacteria. Conclusion: The results indicate that regular tooth brushing with continuous 4% hypertonic saline solution mouth washing education promotes oral health for elders in long term care facilities, thus the dental care described in this study is recommended for elders in long term facilities.

• 대한화학회지
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• 제58권6호
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• pp.528-534
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• 2014

어떤 이성분계용액에서는 상한임계용액온도와 하한임계용액온도가 동시에 나타나는 원형모양의 온도-조성 상도를 보인다. 이러한 현상은 분자간 특정상호작용이 존재하는 경우 나타나는 것으로 알려져 있다. 특정상호작용을 묘사하는 방법에는 여러 가지가 있다. 본 연구에서는 특정상호작용의 총수가 이항분포에 따라 분포한다고 가정하였다. 이 경우 특정상호작용을 Regular 용액이론, Quasichemical 이론 그리고 Flory-Huggins 격자이론에 적용하였을 때 원형모양의 온도-조성 상도를 보이는 경우에 대한 정확한 수학적인 조건을 유도하였다. 그리고 매개변수들이 온도-조성상도에 미치는 영향을 조사하였고, 물-니코틴에 대한 온도-조성상도를 계산하여 실험값과 비교하여 보았다.