• Communications of the Korean Mathematical Society
• /
• v.26 no.4
• /
• pp.585-589
• /
• 2011

Using algebraic methods, we prove that every Jordan (${\varphi},{\psi}$derivation is a (${\varphi},{\psi}$derivation under certain conditions. In particular, we conclude that every Jordan ${\theta}$-derivation is a ${\theta}$-derivatio.

• Journal of the Chungcheong Mathematical Society
• /
• v.28 no.1
• /
• pp.139-143
• /
• 2015

In this paper, we prove that (r, s)-semi-irresolute image of the (r, s)-semi-${\theta}$-connected set is also (r, s)-semi-${\theta}$-connected. Moreover, we prove that an (r, s)-semi-irresolute mapping preserves (r; s)-$S^*$-closedness.

• Journal of the Korean Data and Information Science Society
• /
• v.4
• /
• pp.87-95
• /
• 1993

We find a class of admissible Bayes estimator for the mean vector ${\theta}=({\theta}_{1},{\theta}_{2},...,{\theta}_{p}$ of Poisson distribution under a LINEX loss function. The Monte Carlo Simulation is performed to compare the emprical Bayes estimater under the LINEX loss function and weighted squared error loss respectively.

• The Pure and Applied Mathematics
• /
• v.9 no.1
• /
• pp.47-55
• /
• 2002

In this pope., we consider a Minty's lemma for ($\theta ,\eta$)-pseudomonotone-type set-valued mappings in real Banach spaces and then we show the existence of solutions to variational-type inequality problems for ($\theta ,\eta$)-pseudomonotone-type set-valued mappings in nonreflexive Banach spaces.

• Bulletin of the Korean Mathematical Society
• /
• v.41 no.4
• /
• pp.647-656
• /
• 2004

In this paper, by using operations, some characterizations and some properties of fuzzy lower and upper continuous multifunctions and its weaker and stronger forms including fuzzy lower and upper weakly continuous, fuzzy lower and upper ${\theta}-continuous$, fuzzy lower and upper strongly ${\theta}-continuous$, fuzzy lower and upper almost strongly ${\theta}-continuous$, fuzzy lower and upper weakly ${\theta}-continuous$, fuzzy lower and upper almost continuous, fuzzy lower and upper super continuous, fuzzy lower and upper ${\delta}-continuous$, are presented.

• Bulletin of the Korean Mathematical Society
• /
• v.52 no.1
• /
• pp.287-299
• /
• 2015

A theta graph is the union of three internally disjoint paths that have the same two distinct end vertices. We show that every graph of order $n{\geq}12$ and size at least ${\lfloor}\frac{11n-18}{2}{\rfloor}$ contains three disjoint theta graphs. As a corollary, every graph of order $n{\geq}12$ and size at least ${\lfloor}\frac{11n-18}{2}{\rfloor}$ contains three disjoint cycles of even length.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.794-798
• /
• 1995

We performed analysis for crank shaft and connecting rod in driving device of Cold Heading Machine. The results of this study is following ; 1. The nominal pressure is happened at 8mm under bottom dead center. And then the theoretical angel of crank (.theta.) and connecting rod (.phi.) are .theta. = 25 .deg. 1' and .phi.= 6 .deg. 1' but the analysis angel are .theta. = 25 .deg. and .phi.= 7 .deg. 2. The load is loaded at theta. = 51 .deg. in crank angle. 3. The maximum stress of connecting rod is about290MPa. It is exited inner stress range in consideration of safety factor.

• Bulletin of the Korean Mathematical Society
• /
• v.33 no.3
• /
• pp.377-383
• /
• 1996

We consider in this paper the following nonlinear regression model $$ (1.1) y_t = f(x_t, \theta_o) + \in_t, t = 1, \ldots, n, $$ where $y_t$ is the tth response, $x_t$ is m-vector imput variable, $\theta_o$ is a p-vector of unknown parameter belong to a parameter space $\Theta, f:R^m \times \Theta \ to R^1$ is a nonlinear known function, and $\in_t$ are independent unobservable random errors with finite second moment.

• Communications of the Korean Mathematical Society
• /
• v.28 no.2
• /
• pp.371-381
• /
• 2013

In this paper, we investigate some properties of ${\theta}$-($\mathcal{G}$, $\mathcal{H}$)-continuous functions in a grill topological spaces. Moreover, the relationships with other related functions are investigated.

• Journal of the Korean Mathematical Society
• /
• v.35 no.4
• /
• pp.981-997
• /
• 1998

We shall show first general Metivier operators ${D_y}^2+(x^{2l}+y^{2k}){D_x}^2,l,k=1,2,....,have {G_{x,y}}^{{\theta,d}}$-hypoellipticity in the vicinity of the origin (0,0), where $\theta=\frac{l(1+k)}{l(1+k)-k},\;d=\frac{\theta+k}{1+k}$ (＞1), and finally the optimality of these exponents {$\theta$, d} will be shown.