• The Korean Journal of Community Living Science
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• v.25 no.4
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• pp.601-608
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• 2014

This study evaluates changes in yogurt with Ulmus davidiana var. japonica (U. davidiana) in terms of its physicochemical, microbial, and sensory properties during storage. The pH value and mean microbial counts of this yogurt with 0.2 to 0.8% of U. davidiana added ranged from 4.1 to 4.3 and from $1.4{\times}10^8$ to $2.3{\times}10^8cfu/mL$, respectively, during storage at $7^{\circ}C$ for 16 d. In terms of its color, the L value was significantly higher in the control and U. davidiana yogurt 0.2 to 0.4% up to 4 d, than other yogurt samples, and the b value was influenced by the addition of U. davidiana over 0.6% throughout the storage. According to a sensory test, there was a significant difference in the yellowness score between U. davidiana yogurt and the control, but earthy, and bitterness, and viscosity scores were similar. Overall acceptability was not significantly influenced after 8 d of storage in all yogurt samples, including the control. According to these results, concentrations (0.2 and 0.4%) of U. davidiana yogurt had no significantly adverse effects on its physicochemical, microbial, and sensory properties.

• Journal of applied mathematics & informatics
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• v.18 no.1_2
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• pp.497-503
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• 2005

This paper presents characterizations on the independence of the exponential and Pareto distributions by record values. Let ${X_{n},\;n {\ge1}$ be a sequence of independent and identically distributed(i.i.d) random variables with a continuous cumulative distribution function(cdf) F(x) and probability density function(pdf) f(x). $Let{\;}Y_{n} = max{X_1, X_2, \ldots, X_n}$ for n \ge 1. We say $X_{j}$ is an upper record value of ${X_{n},{\;}n\ge 1}, if Y_{j} > Y_{j-1}, j > 1$. The indices at which the upper record values occur are given by the record times {u(n)}, n \ge 1, where u(n) = $min{j|j > u(n-1), X_{j} > X_{u(n-1)}, n \ge 2}$ and u(l) = 1. Then F(x) = $1 - e^{-\frac{x}{a}}$, x > 0, ${\sigma} > 0$ if and only if $\frac {X_u(_n)}{X_u(_{n+1})} and X_u(_{n+1}), n \ge 1$, are independent. Also F(x) = $1 - x^{-\theta}, x > 1, {\theta} > 0$ if and only if $\frac {X_u(_{n+1})}{X_u(_n)}{\;}and{\;} X_{u(n)},{\;} n {\ge} 1$, are independent.

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.329-337
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• 2007

In the paper, we obtain the existence of positive solutions and establish a corresponding iterative scheme for BVPs $$\{^{\;(\phi_p(u'))'\;+\;q(t)f(t,u)=0,\;0\;<\;t\;<\;1,}_{\;u(0)\;-\;B(u'({\eta}))\;=\;0,\;u'(1)\;=\;0}$$ and $$\{^{\;(\phi_p(u'))'\;+\;q(t)f(t,u)=0,\;0\;<\;t\;<\;1,}_{\;u'(0)\;=\;0,\;u(1)+B(u'(\eta))\;=\;0.}$$. The main tool is the monotone iterative technique. Here, the coefficient q(t) may be singular at t = 0, 1.

• 한국태양에너지학회:학술대회논문집
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• 2009.11a
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• pp.32-37
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• 2009

An energy loss through the window system occupies about 10 to 30 percent on energy consumption of the whole building. That is the reason, several elements for a building composition of window system are the weakest from the heat. Insulation performance increases for the reducing heat loss. Heat transfer through the window system that is reducing heat transfer through conduction, convection and radiation. Insulation performance reinforcement methods classify improving heat specific quality of window system and improving efficiency of whole window system. The most application method among each methods is reducing emission ratio of the window system(Low-E glass), increasing a number of glazing(multiple window) and a method of vacuuming between glazing and glazing. Therefore this study is investigated a sort of glazing and specific character, U-value calculation with changing glazing thickness and calculation of temperature distribution and U-value with a glazing charging gas kind from double glazing. For a conclusion, an aspect of U-value figure at the smallest value case of vacuum glazing with Low-E coating. That means insulation efficiency is the best advantage during a building plan selecting vacuum glazing with Low-E coating for a energy saving aspect. In this way, U-value become different the number of glazing, coating whether or not and selecting injection gas. Therefore selecting of glazing is very important after due consideration by a characteristic and use of building and consideration of strong point and weak point.

• Journal of applied mathematics & informatics
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• v.30 no.3_4
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• pp.517-529
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• 2012

In this paper, the existence theorem of two positive solutions is established for nonlinear m-point boundary value problem by using an inequality for the following third-order differential equations $$({\phi}(u^{\prime\prime}))^{\prime}+a(t)f(t,u(t))=0,\;t{\in}(0,1)$$, $${\phi}(u^{\prime\prime}(0))=\sum^{m-2}_{i=1}a_i{\phi}(u^{\prime\prime}({\xi}_i)),\;u^{\prime}(1)=0,\;u(0)=\sum^{m-2}_{i=1}b_iu({\xi}_i)$$, where ${\phi}:R{\rightarrow}R$ is an increasing homeomorphism and homomorphism and $\phi(0)=0$. The nonlinear term f may change sign, as an application, an example to demonstrate our results is given.

• Journal of the Korean Mathematical Society
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• v.58 no.5
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• pp.1109-1129
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• 2021

This paper considers an anisotropic polytropic infiltration equation with a source term $$u_t={\sum\limits_{i=1}^{N}}{\frac{{\partial}}{{\partial}x_i}}\(a_1(x){\mid}u{\mid}^{{\alpha}_i}{\mid}u_{x_i}{\mid}^{p_i-2}u_{x_i}\)+f(x,t,u)$$, where p_i > 1, α_i > 0, a_i(x) ≥ 0. The existence of weak solution is proved by parabolically regularized method. Based on local integrability $u_{x_i}{\in}W_{loc}^{1,p_i}(\Omega)$, the stability of weak solutions is proved without boundary value condition by the weak characteristic function method. One of the essential characteristics of an anisotropic equation different from an isotropic equation is found originally.

• Communications of the Korean Mathematical Society
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• v.17 no.3
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• pp.535-540
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• 2002

Let X$_1$, X$_2$‥‥,X$\_$n/ be n independent and identically distributed random variables with continuous cumulative distribution function F(x). Let us rearrange the X's in the increasing order X$\_$1:n/ $\leq$ X$\_$2:n/ $\leq$ ‥‥ $\leq$ X$\_$n:n/. We call X$\_$k:n/ the k-th order statistic. Then X$\_$n:n/ - X$\_$n-1:n/ and X$\_$n-1:n/ are independent if and only if f(x) = 1-e(equation omitted) with some c > 0. And X$\_$j/ is an upper record value of this sequence lf X$\_$j/ > max(X$_1$, X$_2$,¨¨ ,X$\_$j-1/). We define u(n) = min(j|j > u(n-1),X$\_$j/ > X$\_$u(n-1)/, n $\geq$ 2) with u(1) = 1. Then F(x) = 1 - e(equation omitted), x > 0 if and only if E[X$\_$u(n+3)/ - X$\_$u(n)/ | X$\_$u(m)/ = y] = 3c, or E[X$\_$u(n+4)/ - X$\_$u(n)/|X$\_$u(m)/ = y] = 4c, n m+1.

• Bulletin of the Korean Mathematical Society
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• v.47 no.2
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• pp.411-422
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• 2010

By using the fixed point index theory, we investigate the existence of at least two positive solutions for p-Laplace equation with sign-changing nonlinear terms $(\varphi_p(u'))'+a(t)f(t,u(t),u'(t))=0$, subject to some boundary conditions. As an application, we also give an example to illustrate our results.

• Journal of applied mathematics & informatics
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• v.5 no.1
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• pp.223-233
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• 1998

This paper is concerned with the problem of existence of solutions to the initial value problem u'(t) = A(t, u(t)), u(a) = z in a probabilistic normed space where $A : [a,b)\;{\times}\;D->E$ is continuous, D is a closed subset of a probabilistic normed space E, and $z\;{\in}\;D$. With a dissipative type condition on A, we estabilish sufficient conditions for this initial value problem to have a solution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.5
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• pp.2249-2253
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• 2011

This paper analyzed the problems of the Korean output regulation in the relevant band through an analytic comparison of the current trend of each country and their standard values concerning the technical standard of low power u-IT equipments. In connection with the standard value of technical values of each country, which has been proposed in the registration of the appropriate electric wave, the paper aims to propose the standard value that could actually be introduced for suitable low power u-IT installations in Korea. Provided that the Korean standard may be upgraded based on the tolerances of technical standards proposed in this paper, this is expected to be committed to the distribution and advancement of low power u-IT equipments; and further, it is anticipated to be prepared with competitiveness not only in the Korean communications market, but also in the international communications market.