• Journal of applied mathematics & informatics
• /
• v.30 no.1_2
• /
• pp.161-171
• /
• 2012

We consider the fourth-order differential equation with one-dimensional $p$-Laplacian (${\phi}_p(x^{\prime\prime}(t)))^{\prime\prime}=f(t,x(t),x^{\prime}(t),x^{\prime\prime}(t)$) a.e. $t{\in}[0,1]$, subject to the boundary conditions $x^{\prime\prime}}(0)=0$, $({\phi}_p(x^{\prime\prime}(t)))^{\prime}{\mid}_{t=0}=0$, $x(0)={\sum}_{i=1}^n{\mu}_ix({\xi}_i)$, $x(t)=x(1-t)$, $t{\in}[0,1]$, where ${\phi}_p(s)={\mid}s{\mid}^{p-2}s$, $p$ > 1, 0 < ${\xi}_1$ < ${\xi}_2$ < ${\cdots}$ < ${\xi}_n$ < $\frac{1}{2}$, ${\mu}_i{\in}\mathbb{R}$, $i=1$, 2, ${\cdots}$, $n$, ${\sum}_{i=1}^n{\mu}_i=1$ and $f:[0,1]{\times}\mathbb{R}^3{\rightarrow}\mathbb{R}$ is a $L^1$-Carath$\acute{e}$odory function with $f(t,u,v,w)=f(1-t,u,-v,w)$ for $(t,u,v,w){\in}[0,1]{\times}\mathbb{R}^3$. We obtain the existence of at least one nonconstant symmetric solution by applying an extension of Mawhin's continuation theorem due to Ge. Furthermore, an example is given to illustrate the results.

• Korean Journal of Pharmacognosy
• /
• v.30 no.1
• /
• pp.1-6
• /
• 1999

To evaluate cytotoxic effect and topoisomerase I inhibition activity of Caesalpinia sappan L., both water and methanol extracts were examined using in vitro assay. The cytotoxic effect of Caesalpinia sappan L. examined using MTT and SRB assay and $IC_{50}$ values were measured against U937, HL60, HepG2, SNU-1, SNU-16 cancer cell lines. Among them the representative cytotoxic results are shown as follows; water extract (U937=13.39 ${\mu}g/ml$, HL60=8.65 ${\mu}g/ml$, HepG2=38.48 ${\mu}g/ml$, SNU-1=7.72 ${\mu}g/ml$, SNU-16=25.49 ${\mu}g/ml$), methanol extract (U937=13.35 ${\mu}g/ml$, HL60=9.43 ${\mu}g/ml$, HepG2=25.67 ${\mu}g/ml$, SNU-1=8.37 ${\mu}g/ml$, SNU-16=28.64 ${\mu}g/ml$). The inhibitory concentration of DNA topoisomerase I activity against water extract was 100 ${\mu}g/ml$ and the inhibitory concentration of DNA topoisomerase I against methanol extract was 400 ${\mu}g/ml$.

• Journal of Korean Medical classics
• /
• v.20 no.2
• /
• pp.25-30
• /
• 2007

It is well-known fact that Korean medicine is related to Taoism. Dong-$\breve{u}$ibogam(東醫寶鑑) was written by Heo-Jun(許浚) in Jo-seon(朝鮮) dynasty. Heo-Jun complied all of past studies on Korean medicine in this book. On the basis of Naegyoung(內徑), he accepted the theory of four eminent physicians of the K$\breve{u}$m and Won Dynasty(金元時代) in ancient China and Eubangyouchui(醫方類聚), $\breve{U}$irimch'waryo(醫林撮要), Hyang-yakjips$\breve{o}$ngbang(鄕藥集成方) in Jo-seon. Especially, Dong-$\breve{u}$ibogam is so characteristic of Taoism than any other medical books written in China or Korea before. In this study, I researched the relation between Dong-$\breve{u}$ibogam and Taosim on the views of authors, organization, reference hooks, contents.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.06a
• /
• pp.139-142
• /
• 2007

본 연구는 RAS 계수법과 동태적 산업연관 모형을 동시에 적용하여 u-City 구축의 경제적 파급효과를 분석하였다는 점에서 통상적인 산업연관분석과 차별성을 지닌다. 한국은행이 가장 최근 발표한 산업연관표는 2000년도 자료이다. 본 연구는 RAS 계수법으로 알려져 있는 예측기법을 이용하여 2000년 산업연관표를 2010년 표로 연장시켜 u-City 산업의 경제적 파급효과를 분석한다. 한편 산업연관분석에 통상적으로 사용되고 있는 모형은 정태적 분석모형인 기본 산업연관 모형이지만, 본 연구에서는 동태적 산업연관 모형을 적용하여 u-City 산업의 경제적 파급효과를 동태적으로 분석하였다. u-City 구축에 따른 총 생산파급효과는 약 3.3배로 추정되었으며, u-City 산업은 전방연쇄효과는 매우 높지만 후방연쇄효과는 그다지 높지 않은 것으로 나타났다.

• Kyungpook Mathematical Journal
• /
• v.48 no.4
• /
• pp.593-611
• /
• 2008

Global attractivity and oscillatory behavior of the following nonlinear impulsive parabolic differential equation which is a general form of many population models $$\array{\{{{\frac {{\partial}u(t,x)}{{\partial}t}=\Delta}u(t,x)-{\delta}u(t,x)+f(u(t-\tau,x)),\;t{\neq}t_k,\\u(t^+_k,x)-u(t_k,x)=g_k(u(t_k,x)),\;k{\in}I_\infty,}\;\;\;\;\;\;\;\;(*)$$ are considered. Some new sufficient conditions for global attractivity and oscillation of the solutions of (*) with Neumann boundary condition are established. These results no only are true but also improve and complement existing results for (*) without diffusion or impulses. Moreover, when these results are applied to the Nicholson's blowflies model and the model of Hematopoiesis, some new results are obtained.

• Journal of Magnetics
• /
• v.10 no.2
• /
• pp.71-75
• /
• 2005

An effective method, i.e., the solid atom method, is suggested to obtain the Coulomb interaction parameter, U, and the Hund exchange coupling constant, J, for use in the LDA+U calculation. The par~meters are obtained self-consistently during the LDA+U calculation. The method is applied to typical transition metal oxides and $MnB^{VI}(B^{VI}=S,Se,Te)$. The U values for the transition metal oxides have similar magnitude to previous calculations although they are obtained by a much simpler method. $MnB^{VI}s$ have been characterized as crossroads materials between charge transfer and band insulators by the LDA+U calculation.

• Communications of the Korean Mathematical Society
• /
• v.37 no.1
• /
• pp.137-161
• /
• 2022

In this article, we study the existence and multiplicity of homoclinic solutions for the following fourth-order differential equation (1) u⁽⁴⁾(x) + ωu''(x) + a(x)u(x) = f(x, u(x)), ∀x ∈ ℝ where a(x) is not required to be either positive or coercive, and F(x, u) = ∫^u₀ f(x, v)dv is of subquadratic or superquadratic growth as |u| → ∞, or satisfies only local conditions near the origin (i.e., it can be subquadratic, superquadratic or asymptotically quadratic as |u| → ∞). To the best of our knowledge, there is no result published concerning the existence and multiplicity of homoclinic solutions for (1) with our conditions. The proof is based on variational methods and critical point theory.

• Journal of Korean Library and Information Science Society
• /
• v.37 no.1
• /
• pp.305-328
• /
• 2006

This paper is a bibliographic analysis on printed books of $M\grave{e}ngz\check{i}$(孟子) in Choseon Dynasty. Through examination of the physical characteristics of books in many institutes and private collections, $M\grave{e}ngz\check{i}j\acute{i}zh\grave{u}d\grave{a}q\acute{a}n$(孟子集註大全)was systematically explored, which was the most frequently published $M\grave{e}ngz\check{i}$(孟子) in Choseon Dynasty. $M\grave{e}ngz\check{i}$(孟子) was published mainly in Kyungki and Kyungsang provinces, and in the period of 17C to 19C. There are two streams of $M\grave{e}ngz\check{i}j\acute{i}zh\grave{u}d\grave{a}q\acute{a}n$. One is the series of the reprinted edition of $M\acute{i}ngbon$(明本覆刻), originated from Saseookyungdaejun(四書五經大全), compiled by Hokwang(湖廣) and colleagues in $M\acute{i}ng$(明). The second is the series of Chungyuja books(丁酉字本) among movable type books of Choseon(朝鮮活字本), the contents of which being the same as the other stream. Also, $M\grave{e}ngz\check{i}d\grave{a}iw\acute{e}n$(孟予大文) and $M\grave{e}ngz\check{i}zh\grave{e}ngw\acute{e}n$(孟子正文) are frequently published.

• International Journal of Contents
• /
• v.10 no.3
• /
• pp.1-8
• /
• 2014

In this paper, we collect and analyze the status of mobile phone applications (hereafter apps) in the healthcare and fitness category of the Apple iTunes App Store and Google Play Store. We determine the number of apps and analyze statistical aspects such as classifications, age rating, fees, and user evaluation of the popular items. As of September 30, 2013, there were 236 popular apps available from iTunes. Google Play offered 720 apps. We discover that apps for healthcare and fitness are diverse. Apps for physical exercise have the greatest popularity. The proportions of apps that are suitable for all ages among the Google and iTunes popular apps are 55.8% and 89.4%, respectively. The user evaluation of apps in iTunes is relatively less positive. We determine that the proportion of paid apps to free apps in Google is higher than that of the apps in iTunes. We perform hypothesis tests and find statistically significant differences in age rating and perceived satisfaction between the apps of the Apple iTunes App Store and Google Play Store. However, we find no meaningful differences in the classification and price of the apps between the two app stores. We perform hypothesis tests to verify the differences in age rating and perceived satisfaction between the paid and free apps within and across the Google Play Store and iTunes App Store. There are statistically significant differences in the age rating between the paid and free apps in the Google play store, between the Google free and iTunes free apps, between the Google paid and iTunes paid apps, between the Google free and iTunes paid apps, and between the Google paid and iTunes free apps. There are statistically significant differences in the perceived satisfaction between the Google free and iTunes free apps, between the Google paid and iTunes paid apps, between the Google free and iTunes paid apps, and between the Google paid and iTunes free apps.

• Proceedings of the Korean Society of Computational and Applied Mathematics Conference
• /
• 2003.09a
• /
• pp.6-6
• /
• 2003

In this work we consider the mathematical formulation and numerical resolution of the linear feedback control problem for Boussinesq equations. The controlled Boussinesq equations is given by $$\frac{{\partial}u}{{\partial}t}-{\nu}{\Delta}u+(u{\cdot}{\nabla}u+{\nabla}p={\beta}{\theta}g+f+F\;\;in\;(0,\;T){\times}\;{\Omega}$$, $${\nabla}{\cdot}u=0\;\;in\;(0,\;T){\times}{\Omega}$$, $$u|_{{\partial}{\Omega}=0,\;u(0,x)=\;u_0(x)$$ $$\frac{{\partial}{\theta}}{{\partial}t}-k{\Delta}{\theta}+(u{\cdot}){\theta}={\tau}+T,\;\;in(0,\;T){\times}{\Omega}$$ $${\theta}|_{{\partial}{\Omega}=0,\;\;{\theta}(0,X)={\theta}_0(X)$$, where $\Omega$ is a bounded open set in $R^{n}$, n=2 or 3 with a $C^{\infty}$ boundary ${\partial}{\Omega}$. The control is achieved by means of a linear feedback law relating the body forces to the velocity and temperature field, i.e., $$f=-{\gamma}_1(u-U),\;\;{\tau}=-{\gamma}_2({\theta}-{\Theta}}$$ where (U,$\Theta$) are target velocity and temperature. We show that the unsteady solutions to Boussinesq equations are stabilizable by internal controllers with exponential decaying property. In order to compute (approximations to) solution, semi discrete-in-time and full space-time discrete approximations are also studied. We prove that the difference between the solution of the discrete problem and the target solution decay to zero exponentially for sufficiently small time step.