• Bulletin of the Korean Mathematical Society
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• v.53 no.6
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• pp.1741-1751
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• 2016

We prove the boundary Harnack principle and the Carleson type estimate for ratios of solutions u/v of non-divergence second order elliptic equations $Lu=a_{ij}D_{ij}+b_iD_iu=0$ in a bounded domain ${\Omega}{\subset}R_n$. We assume that $b_i{\in}L^n({\Omega})$ and ${\Omega}$ is a $H{\ddot{o}}lder$ domain of order ${\alpha}{\in}$ (0, 1) satisfying a strong regularity condition.

• Korean Journal of Mathematics
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• v.17 no.4
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• pp.451-460
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• 2009

We consider the existence of solutions of a nonlinear biharmonic equation with Dirichlet boundary condition, ${\Delta}^2u+c{\Delta}u=f(x, u)$ in ${\Omega}$, where ${\Omega}$ is a bounded open set in $R^N$ with smooth boundary ${\partial}{\Omega}$. We obtain two new results by linking theorem.

• Bulletin of the Korean Mathematical Society
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• v.33 no.4
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• pp.631-638
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• 1996

The parabolic free boundary problem with Puschino dynamics is given by (see in [3]) $$ (1) { \upsilon_t = D\upsilon_{xx} - (c_1 + b)\upsilon + c_1 H(x - s(t)) for (x,t) \in \Omega^- \cup \Omega^+, { \upsilon_x(0,t) = 0 = \upsilon_x(1,t) for t > 0, { \upsilon(x,0) = \upsilon_0(x) for 0 \leq x \leq 1, { \tau\frac{dt}{ds} = C)\upsilon(s(t),t)) for t > 0, { s(0) = s_0, 0 < s_0 < 1, $$ where $\upsilon(x,t)$ and $\upsilon_x(x,t)$ are assumed continuous in $\Omega = (0,1) \times (0, \infty)$.

• Journal of the Korean Mathematical Society
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• v.34 no.3
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• pp.633-651
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• 1997

For a non-degenerate symmetric bilinear form $\sigma$ on a finite dimensional vector space E, the Jordan algebra of $\sigma$-symmetric operators has a symmetric cone $\Omega_\sigma$ of positive definite operators with respect to $\sigma$. The cone $C_\sigma$ of elements (x,y) \in E \times E with \sigma(x,y) \geq 0$ gives the compression semigroup. In this work, we show that in the sutomorphism group of the tube domain over $\Omega_\sigma$, this semigroup has a UDL and Ol'shanskii decompositions and is exactly the compression semigroup of $\Omega_sigma$.

• Journal of the Chungcheong Mathematical Society
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• v.19 no.3
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• pp.213-218
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• 2006

The 2D g-Navier-Stokes equations are a certain modified Navier-Stokes equations and have the following form, $$\frac{{\partial}u}{{\partial}t}-{\nu}{\Delta}u+(u{\cdot}{\nabla})u+{\nabla}p=f$$, in ${\Omega}$ with the continuity equation ${\nabla}{\cdot}(gu)=0$, in ${\Omega}$, where g is a suitable smooth real valued function. In this paper, we will derive 2D g-Navier-Stokes equations from 3D Navier-Stokes equations. In addition, we will see the relationship between two equations.

• Communications of the Korean Mathematical Society
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• v.11 no.1
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• pp.273-280
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• 1996

In this paper we extend the concept of the Sobolev wave front set of a distribution to the one of the generalized Sobolev wave front set of a generalized distribution, and we investigate the relations among these concepts. Finally, we prove the local property of these sets.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.4
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• pp.273-278
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• 2016

In this paper, chaotic circuit of the Lorentz system using multipliers, operational amplifiers, capacitor, fixed resistor and variable resistor for control has been designed in a electronic circuit. Through PSPICE program, electrical characteristics such as time waveforms, frequency spectra and phase attractors analyzed. And in the special area ($10{\sim}100k{\Omega}$) of the $500k{\Omega}$ control variable resistor, the circuit showed chaotic dynamics. Also, we implemented the circuit in a electronic hardware system with discrete elements. Measured results of the circuit coincided with simulated data.

• Archives of Pharmacal Research
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• v.19 no.1
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• pp.62-65
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• 1996

A homologous series of twenty, hitherto unreported, analogues of 5-halosubstituted $1, 3-Bis(\omega-cyanoalkyl)uracil$acyclic nucleosides were synthesized by the series of alkylation reactions of 5-halouracils with the corresponding chloroacetonitrile, chloropropionitrile, chlorobutyronitrile and 5-chlorovaleronitrile $(Cl-(C_ 2)_n-CN: n=l, 2, 3, 4)\; in\; anhydrous\; DMSO\; (or DMF)/K_2CO_3(or NaH)\; under\; 75^{\circ}C$ temperature. Antitumor activities for the synthesized compounds were determined against three cell lines (FM-3A cell, P-388 cell and U-938 cell lines). The compounds that exhibited moderate activity to significant activity, included la-b, 2a-b, 3a-c, and 4a, whose compounds were active against P-388, FM-3A and U-937 cell lines with the compounds la, lb, and 2a, showing significant antitumor activity (inhibitory concentrations $(IC_{50})$ ranged from 2.2 to $7.0\mug/ml$). Their strucrure-activity relationship did not show any activity differences in their effective chain length (methyl, ethyl, propyl, butyl) in 1, 3-bis(.omega.-cyanoalkyl) uracils.

• Proceedings of the KIEE Conference
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• 2007.04b
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• pp.37-39
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• 2007

금속의 전기 비저항 측정방법은 일반적으로 4단자, van der Pauw, Four-Point Probe(FPP), eddy current 방법 등이 있다. 이들의 측정방법들은 각각 다르지만 동일한 시료에 대한 전기 비저항 측정값은 거의 같은 결과를 나타내어 야 한다. 금속 전기 비저항의 정밀측정에 대한 연구를 위하여 비자성 금속인 STS 316 시료를 선정하여 측정한 결과 4단자와 van der Pauw 방법으로 측정된 비저항은 각각 $75.86{\mu}g\Omega{\cdot}cm$(2.273 %IACS), $75.80{\mu}g\Omega{\cdot}cm$(2.275 %IACS)이며, 측정 불확도는 0.25 %로서 거의 동등한 결과를 나타냈고, Four Point Probe(FPP) 방법으로 측정된 비저항은 $75.36{\mu}g\Omega{\cdot}cm$(2.288 %IACS), 측정 불확도는 0.45 %, eddy current 방법으로 측정된 비저항은 $76.63{\mu}g\Omega{\cdot}cm$(2.25 %IACS), 측정 불확도는 0.64 %로 나타났다.

• Journal of Nutrition and Health
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• v.42 no.3
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• pp.246-255
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• 2009

The development of food frequency questionnaire (FFQ) is based on food use and/or dish use. Regardless of potential effect of oils and seasonings on chronic diseases, most of food-based FFQs do not include oils and seasonings in calculation of nutrient intake. This study examined the effect of added (seasoning) oils and seasonings on the distribution of subjects by relative nutrient intake using a dish-based FFQ. The subjects were 1,303 persons (men 478, women 825) aged over 20 years old, who completed FFQ composed of 121 items. Three types of daily nutrient intake were calculated; 1) total nutrient intake with oils and seasonings, 2) nutrient intake without oils, and 3) nutrient intake without oils and seasonings. The correlation and agreement of classification of subjects by relative nutrient intake were examined. All analyses were performed using absolute nutrient intakes and total energy-adjusted nutrient intakes by residual method. Comparing total nutrient intake with the nutrient intake without oils, energy, vegetable fat and vitamin E intake were significantly decreased and kappa values were 0.95 (${\kappa}{\omega}$ = 0.98), 0.64 (${\kappa}{\omega}$ = 0.81), and 0.59 (${\kappa}{\omega}$ = 0.79), respectively. Comparing total nutrient intake with the nutrient intake without oils and seasonings, most of nutrients intake except animal fat, animal protein, retinol and cholesterol were significantly decreased, and kappa values of vegetable fat (${\kappa}$ = 0.64, ${\kappa}{\omega}$ = 0.81), vitamin E (${\kappa}$ = 0.59, ${\kappa}{\omega}$ = 0.79) and sodium (${\kappa}$ = 0.61, ${\kappa}{\omega}$ = 0.80) were under 0.80. After total energy was adjusted, agreement was lower than before total energy adjustment. Excluding oils and seasonings to assess nutrient intake underestimated vegetable fat, vitamin E and sodium intake and affected the distribution of subjects by their relative nutrient intake. Therefore, we suggest that research focused on these nutrients need to be cautious about the interpretation of the results.