• Journal of applied mathematics & informatics
• /
• v.35 no.5_6
• /
• pp.505-512
• /
• 2017

In this paper, we explain how the exact closed-form solutions of the classical problems of viscous fluid flow over a heated stretching plate and shrinking sheet can be obtained by a reliable method.

• Communications of the Korean Mathematical Society
• /
• v.11 no.2
• /
• pp.471-480
• /
• 1996

Consider a strong Markov process $X^0$ that has continuous sample paths in the closed cone $\bar{G}$ in $R^d(d \geq 3)$ such that the process behaves like a ordinary Brownian motion in the interior of the cone, reflects instantaneously from the boundary of the cone and is absorbed at the vertex of the cone. It is shown that $X^0(t)$ has a representation $R(t) \ominus (t)$ where $R(t) \in [0, \infty)$ and $\ominus(t) \in S^{d-1}$, the surface of the unit ball.

• Communications of the Korean Mathematical Society
• /
• v.28 no.1
• /
• pp.155-162
• /
• 2013

Although the snowflake curve, the boundary of the Koch snowflake, is one of the well-known fractals, there is no iterated function system (IFS) for it in the literature. In this study, we give an IFS for this familiar closed curve.

• Journal of applied mathematics & informatics
• /
• v.20 no.1_2
• /
• pp.197-208
• /
• 2006

This paper deals with the exact solution of surface gravity waves in an ocean with irregular bed topography. In order to obtain water surface elevation and run-up of infra-gravity waves when the bed is either wavy or exponential, closed form solutions are obtained. Numerical computations indicate that when solitary wave or sinusoidal wave conditions are applied at the boundary, water surface elevation attains near Gaussian profile.

• Journal of the Korean Mathematical Society
• /
• v.46 no.2
• /
• pp.271-279
• /
• 2009

Using an index theory for countably condensing maps, we show the existence of eigenvalues for countably k-set contractive maps and countably condensing maps in an infinite dimensional Banach space X, under certain condition that depends on the quantitative haracteristic, that is, the infimum of all $k\;{\geq}\;1$ for which there is a countably k-set-contractive retraction of the closed unit ball of X onto its boundary.

• Korean Journal of Mathematics
• /
• v.12 no.1
• /
• pp.33-40
• /
• 2004

Let $E,F{\subset}(R^*)^n$ be non-empty sets and let ${\Gamma}$ be this family of all closed curves which join E to F in $(R^*)^n$. In this paper, we shall study the problems of finding properties for the conductance $C({\Gamma})$. And we obtain the inequalities in connection with capacity of condensers.

• Journal of the Korean Institute of Telematics and Electronics S
• /
• v.35S no.7
• /
• pp.37-45
• /
• 1998

In this paper, we extracted heart region using dyamic contour model, increased the vertical resolution of heart region by proposed 2-dimensional interpolation method and visualized the 3-dimensional hearet volutme. the proposed new energy term of dynamic contour model considering the gray level and direction of controur vectors is effective to extract the closed heart boundary. And, we generatedvertical slice images from the extracted heart region images using the 2-dimensional linear interpolation by DT(distance transform). We showed that proposed algorithm is useful by 3-dimensional visualization of heart volume.

• Journal of the Korean Society for Precision Engineering
• /
• v.15 no.7
• /
• pp.91-97
• /
• 1998

The analysis model is the infinite body consisted of power law creep material containing a rigid inclusion with line crack shape subjected to the arbitrarily directional stress on an infinite boundary. The crack analysis is performed using the complex pseudo-stress function. The strain rate intensity factor is determined in the closed form as new fracture mechanics parmeter which represents the magnitudes of stress and strain rate near the tip in power law creep material.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2005.11a
• /
• pp.779-781
• /
• 2005

In this paper, Firstly, it is shown that the bending mode vibration source of vertical pump system is comparatively large because resonance. Secondly in order to reduce the bending mode vibration of vertical pump, The improvement of some boundary condition have been developed and its effectiveness is investigated as appling it at the vertical pump system pratically.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.1
• /
• pp.105-116
• /
• 2003

The flow structure around the free end of a finite circular cylinder (FC) embedded in an atmospheric boundary layer (ABL) over open terrain was investigated experimentally with varying the free end shape. The experiments were carried out in a closed-return type subsonic wind tunnel. A finite cylinder with an aspect ratio (L/D) of 6 was mounted vertically on a long flat plate. The Reynolds number based on the cylinder diameter is about Re=7,500. The velocity fields near the FC free end were measured using the single-frame double-exposure PIV method. As a result, for the FC with a right-angled free end, there is a peculiar vortical structure, showing counter-rotating twin vortices near the FC free end. It is caused by the interaction between the entrained irrotational fluids from both sides of FC and the downwash flow from the FC free-end.