바로가기메뉴

본문 바로가기 주메뉴 바로가기

logo

Vol.20 No.3

Ko, Hansaem ; Kim, Yeonok pp.137-148 https://doi.org/10.7468/jksmeb.2013.20.3.137
초록보기
Abstract

In this paper, we study the Lie-generalized Fibonacci sequence and the root system of rank 2 symmetric hyperbolic Kac-Moody algebras. We derive several interesting properties of the Lie-Fibonacci sequence and relationship between them. We also give a couple of sufficient conditions for the existence of the integral points on the hyperbola <TEX>$\mathfrak{h}^a:x^2-axy+y^2=1$</TEX> and <TEX>$\mathfrak{h}_k:x^2-axy+y^2=-k$</TEX> (<TEX>$k{\in}\mathbb{Z}_{</TEX><TEX>></TEX><TEX>0}$</TEX>). To list all the integral points on that hyperbola, we find the number of elements of <TEX>${\Omega}_k$</TEX>.

Kim, Dong-Soo ; Song, Booseon pp.149-158 https://doi.org/10.7468/jksmeb.2013.20.3.149
초록보기
Abstract

In this article, we study the Gauss map of generalized slant cylindrical surfaces (GSCS's) in the 3-dimensional Euclidean space <TEX>$\mathbb{E}^3$</TEX>. Surfaces of revolution, cylindrical surfaces and tubes along a plane curve are special cases of GSCS's. Our main results state that the only GSCS's with Gauss map G satisfying <TEX>${\Delta}G=AG$</TEX> for some <TEX>$3{\times}3$</TEX> matrix A are the planes, the spheres and the circular cylinders.

Deshpande, Bhavana ; Sharma, Sushil ; Handa, Amrish pp.159-180 https://doi.org/10.7468/jksmeb.2013.20.3.159
초록보기
Abstract

We establish a common fixed point theorem for mappings under <TEX>${\phi}$</TEX>-contractive conditions on intuitionistic fuzzy metric spaces. As an application of our result we study the existence and uniqueness of the solution to a nonlinear Fredholm integral equation. We also give an example to validate our result.

Singh, Deepak ; Ahmed, Amin pp.181-198 https://doi.org/10.7468/jksmeb.2013.20.3.181
초록보기
Abstract

C. Vetro [4] gave the concept of weak non-Archimedean in fuzzy metric space. Using the same concept for Menger PM spaces, Mishra et al. [22] proved the common fixed point theorem for six maps, Also they introduced semi-compatibility. In this paper, we generalized the theorem [22] for family of maps and proved the common fixed point theorems using the pair of semi-compatible and reciprocally continuous maps for one pair and R-weakly commuting maps for another pair in Menger WNAPM-spaces. Our results extends and generalizes several known results in metric spaces, probabilistic metric spaces and the similar spaces.

초록보기
Abstract

We present a 4-dimensional nil-manifold as the first example of a closed non-K<TEX>$\ddot{a}$</TEX>hlerian symplectic manifold with the following property: a function is the scalar curvature of some almost K<TEX>$\ddot{a}$</TEX>hler metric iff it is negative somewhere. This is motivated by the Kazdan-Warner's work on classifying smooth closed manifolds according to the possible scalar curvature functions.

초록보기
Abstract

In this work we study the tribonacci numbers. We find a tribonacci triangle which is an analog of Pascal triangle. We also investigate an efficient method to compute any <TEX>$n$</TEX>th tribonacci numbers by matrix method, and find periods of the sequence by taking modular tribonacci number.

초록보기
Abstract

Alexseev's formula generalizes the variation of constants formula and permits the study of a nonlinear perturbation of a system with certain stability properties. In recent years M. Pinto introduced the notion of <TEX>$h$</TEX>-stability. S.K. Choi et al. investigated <TEX>$h$</TEX>-stability for the nonlinear differential systems using the notion of <TEX>$t_{\infty}$</TEX>-similarity. Applying these two notions, we study bounds for solutions of the perturbed differential systems.

Journal of the Korean Society of Mathematical Education Series B: The Pure and Applied Mathematics