• 대한수학회지
• /
• 제46권6호
• /
• pp.1207-1218
• /
• 2009

The authors study the asymptotic behavior of radial minimizers of an energy functional associated with ferromagnets and antiferromagnets in higher dimensions. The location of the zeros of the radial minimizer is discussed. Moreover, several uniform estimates for the radial minimizer are presented. Based on these estimates, the authors establish global convergence of radial minimizers.

• 대한수학회보
• /
• 제55권2호
• /
• pp.405-413
• /
• 2018

In this work, we use the Faber polynomial expansions to find upper bounds for the coefficients of analytic bi-univalent functions in subclass $\Sigma({\tau},{\gamma},{\varphi})$ which is defined by subordination conditions in the open unit disk ${\mathbb{U}}$. In certain cases, our estimates improve some of those existing coefficient bounds.

• Communications for Statistical Applications and Methods
• /
• 제8권3호
• /
• pp.667-675
• /
• 2001

The usefulness of analysis of variance(ANOVA) estimates of variance components is impaired by the frequent occurrence of negative values. The probability of such an occurrence is therefore of interest. In this paper, we investigate a variety of reasons for negative estimates under one way random effects model. It can be shown, through simulation, that this probability increases when the number of treatments is too small for fixed total observations, unbalancedness of data is severe, ratio of variance components is too small, and data may contain many outliers.

• East Asian mathematical journal
• /
• 제31권5호
• /
• pp.685-693
• /
• 2015

In this paper, we introduce fully discrete mixed discontinuous Galerkin approximations for parabolic problems. And we analyze the error estimates in $l^{\infty}(L^2)$ norm for the primary variable and the error estimates in the energy norm for the primary variable and the flux variable.

• 호남수학학술지
• /
• 제15권1호
• /
• pp.105-120
• /
• 1993

The auxiliary principle technique is used to prove the uniqueness and the existence of solutions for a class of nonlinear variational inequalities and suggest an innovative iterative algorithm for computing the approximate solution of variational inequalities. Error estimates for the finite element approximation of the solution of variational inequalities are derived, which refine the previous known results. An example is given to illustrate the applications of the results obtained. Several special cases are considered and studied.

• Journal of applied mathematics & informatics
• /
• 제12권1_2호
• /
• pp.409-417
• /
• 2003

There are two rotation matrix parameters in a model, pro-posed by Prentice in 1989, for pairs of rotations in 3 dimensional space. For the least squares estimates of the two parameters, an algorithm was also presented, but it turned out that the algorithm could fail to get the least squares estimates. This article provides another algorithm for the least squares estimates and its performance is demonstrated by simulation results.

• ETRI Journal
• /
• 제9권3호
• /
• pp.139-156
• /
• 1987

The problems in software cost management are well known. Cost estimates are too low. Software development projects frequently have cost overruns, which are due to poor estimates. A fair amount of work have been done toward developing cost estimation models. These models vary in their outputs (e. g., total cost, manning schedule) and in the factors used to calculate their estimates. They also vary with regard to the type of formula, parameters, use of previous data, and staffing considerations. This paper will distinguish them by the type of formula they use to calculate total effort and staffing level, and will discuss enough models to demonstrate the characteristics of each model category.

• East Asian mathematical journal
• /
• 제24권3호
• /
• pp.263-274
• /
• 2008

Let $r\;{\geq}\;q$. We get the stability of the estimates of the $\bar{\partial}$-Neumann problem for (p, r)-forms on a weakly q-convex complex submanifold. As a by-product of the stability of the $\bar{\partial}$-estimates, we get the Mergelyan approximation property for (p, r)-forms on a weakly q-convex complex submanifold which satisfies property (P).

• Journal of applied mathematics & informatics
• /
• 제23권1_2호
• /
• pp.571-579
• /
• 2007

Finite difference schemes are considered for a generalization of the Cahn-Hilliard equation with Neumann boundary conditions and the Kuramoto-Sivashinsky equation with a periodic boundary condition, which is of the type $ut+\frac{{\partial}^2} {{\partial}x^2}\;g\;(u,\;u_x,\;u_{xx})=f(u,\;u_x,\;u_{xx})$. Stability and $L^{\infty}$ error estimates of approximate solutions for the corresponding schemes are obtained using the extended Lax-Richtmyer equivalence theorem.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제7권2호
• /
• pp.35-49
• /
• 2003

In this paper, finite volume element methods for nonlinear parabolic integrodifferential problems are proposed and analyzed. The optimal error estimates in $L^p\;and\;W^{1,p}\;(2\;{\leq}\;p\;{\leq}\;{\infty})$ as well as some superconvergence estimates in $W^{1,p}\;(2\;{\leq}\;p\;{\leq}\;{\infty})$ are obtained. The main results in this paper perfect the theory of FVE methods.