• 충청수학회지
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• 제22권1호
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• pp.39-47
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• 2009

Pan, Shen and Woo [8] introduced the concept of the G-sequence of a map. We introduce the G'-sequence of a map, which is a dual concept of the G-sequence of a map. We obtain some sufficient conditions for the all sets in the G'-sequence of a map are groups, and for the exact G'-sequence of a map.

• 대한수학회보
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• 제39권1호
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• pp.175-184
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• 2002

A Cellular embedding of a graph G into an orientable surface S can be considered as a cellular decomposition of S into 0-cells, 1-cells and 2-cells and vise versa, in which 0-cells and 1-cells form a graph G and this decomposition of S is called a map in S with underlying graph G. For a map M with underlying graph G, we define a natural rotation on the line graph of the graph G and we introduce the line map for M. we find that genus of the supporting surface of the line map for a map and we give a characterization for the line map to be embedded in the sphere. Moreover we show that the line map for any life of a map M is map-isomorphic to a lift of the line map for M.

• 대한수학회지
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• 제34권3호
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• pp.653-659
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• 1997

In this paper, we extend the Gottlieb groups of a space to the Gottlieb groups of a map and show some properties of those groups. Especially, We show the 2nd Gottlieb group of a map is contained in the center of the homotopy group of the map and show $G_n(F) = \pi_n(f)$ for an H-map f between H-spaces. We also show the Gottlieb subgroups $G_n(A), G_n(X) and G_n(f)$ make a sequence if the map $f : A \to X$ has a right homotopy inverse.

• Korean Journal of Mathematics
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• 제10권1호
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• pp.19-23
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• 2002

Let X be a Banach space satisfying Opial's condition, C a weakly compact convex subset of $X,F:C{\rightarrow}X$ a nonexpansive map, and let $G:C{\rightarrow}X$ be a compact and demiclosed map. We prove that F + G has a fixed point in C if $F+G:C{\rightarrow}X$ is a weakly inward map.

• 대한수학회지
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• 제35권2호
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• pp.281-294
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• 1998

In this paper, we extend the G-sequence of a CW-pair to the G-sequence of a map and show the existence of a map with nonexact G-sequence. We also give an example of a finite CW-pair with nontrivial $\omega$-homology in high order.

• Korean Journal of Mathematics
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• 제6권2호
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• pp.165-172
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• 1998

For a G-map ${\phi}:X{\rightarrow}X$, we define and characterize the Reidemeister number $R_G({\phi})$ of ${\phi}$. Also, we prove that $R_G({\phi})$ is a G-homotopy invariance and we obtain a lower bound of $R_G({\phi})$.

• 대한수학회논문집
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• 제10권4호
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• pp.949-961
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• 1995

Let f be a smooth G map from a nonsingular real algebraic G variety to an equivariant Grassmann variety. We use some G vector bundle theory to find a necessary and sufficient condition to approximate f by an entire rational G map. As an application we algebraically approximate a smooth G map between G spheres when G is an abelian group.

• 대한수학회보
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• 제49권1호
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• pp.57-61
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• 2012

It is well known that one could use a fixed loxodromic or parabolic element of a non-elementary group $G{\subset}M(\bar{\mathbb{R}}^n)$ as a test map to test the discreteness of G. In this paper, we show that a test map need not be in G. We also construct an example to show that the similar result using an elliptic element as a test map does not hold.

• 호남수학학술지
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• 제32권1호
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• pp.167-176
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• 2010

Let (B, $\check{g}$) and (N, $\hat{g}$) be Einstein manifolds. Then, we get a complete (necessary and sufficient) condition for the warped product manifold $B\;{\times}_f\;N\;:=\;(B\;{\times}\;N,\;\check{g}\;+\;f{\hat{g}}$) to be Einstein, and obtain a complete condition for the Einstein warped product manifold $B\;{\times}_f\;N$ to be weakly stable. Moreover, we get a complete condition for the map i : ($B,\;\check{g})\;{\times}\;(N,\;\hat{g})\;{\rightarrow}\;B\;{\times}_f\;N$, which is the identity map as a map, to be harmonic. Under the assumption that i is harmonic, we obtain a complete condition for $B\;{\times}_f\;N$ to be Einstein.

• 한국산업정보학회논문지
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• 제22권1호
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• pp.23-32
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• 2017

본 논문에서는 이산시간 마코비안 도착과정(discrete-time Markovian arrival process, 이하 이산시간 MAP)을 갖는 대기행렬시스템의 주요성능척도들을 분석하기 위한 통합적 접근방법을 제시한다. 기존의 이산시간 MAP/G/1 대기행렬시스템의 연구들을 보면 동일한 시스템에 대하여 시스템 내 고객수와 대기시간 등을 분석할 때 서로 다른 방법으로 접근하였기에 이 둘을 동시에 살펴보고자 할 때는 추가적인 시간과 노력이 뒤따랐다. 따라서 하나의 시스템을 여러 방면에서 포괄적으로 분석할 수 있는 통합적인 접근방법은 시스템을 설계하고 관리하는 입장에서 볼 때 중요한 분석의 틀이 된다. 본 논문에서는 이산시간 MAP/G/1 시스템의 안정상태 일량 분포를 유도하고 이를 이용하여 임의고객의 대기시간, 체재시간 분포를 유도한다. 체재시간 분포로부터 이탈시점 고객수 분포를 구하고 이탈시점 고객수와 임의시점 고객수와의 관계로부터 고객수 분포를 유도한다.