• 호남수학학술지
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• 제37권4호
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• pp.549-557
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• 2015

We introduce strongly ${\kappa}$-$Fr{\acute{e}}chet$ and strongly ${\kappa}$-sequential spaces which are stronger than ${\kappa}$-$Fr{\acute{e}}chet$ and ${\kappa}$-net spaces respectively. For convenience, we use the terminology "${\kappa}$-sequential" instead of "${\kappa}$-net space", introduced by R.E. Hodel in [5]. And we study some properties and topological operations on such spaces. We also define strictly ${\kappa}$-$Fr{\acute{e}}chet$ and strictly ${\kappa}$-sequential spaces which are more stronger than strongly ${\kappa}$-$Fr{\acute{e}}chet$ and strongly ${\kappa}$-sequential spaces respectively.

• 호남수학학술지
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• 제20권1호
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• pp.79-88
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• 1998

In this paper we define the concept of $Fr{\acute{e}}chet$ function algebras on hemicompact spaces. So we show that under certain condition they can be represented as a projective limit of Banach function algebras. Then the class of $Fr{\acute{e}}chet$ Lipschitz algebras on hemicompact metric spaces are defined and their relations with the class of lipschitz algebras on compact metric spaces are studied.

• 대한수학회지
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• 제44권4호
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• pp.845-854
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• 2007

In this paper we investigate relationships between closure-type and convergence-type properties of hyperspaces over a space X and covering properties of X.

• 호남수학학술지
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• 제34권1호
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• pp.85-92
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• 2012

Our purpose of this paper is to introduce and study some properties related to approximations by points. More precisely, we introduce strongly AP, strongly AFP, strongly ACP, and strongly WAP properties which are stronger than AP, AFP, ACP, and WAP respectively. Also they are weaker than strongly Fr$\acute{e}$chet property. And we study general properties and topological operations on such spaces and give some examples.

• 충청수학회지
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• 제28권4호
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• pp.513-523
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• 2015

We present a local convergence analysis of some Newton-like methods of R-order at least three in order to approximate a solution of a nonlinear equation in a Banach space. Our sufficient convergence conditions involve only hypotheses on the first and second $Fr{\acute{e}}chet$-derivative of the operator involved. These conditions are weaker that the corresponding ones given by Hernandez, Romero [10] and others [1], [4]-[9] requiring hypotheses up to the third $Fr{\acute{e}}chet$ derivative. Numerical examples are also provided in this study.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제22권4호
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• pp.189-194
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• 2016

궤적은 이동체가 움직인 경로이다. IT 기술의 성장은 GPS와 같은 위치 측정 장치를 통해 다양한 이동체의 궤적 데이터를 수집할 수 있게 하였다. 이동체의 궤적은 지리정보시스템(GIS)을 포함한 다양한 연구 분야에서 사용된다. 지리정보시스템 분야에서는 차량의 궤적 데이터를 이용한 전자 도로 지도생성 시도가 많이 이루어져왔다. 이 목표를 이루기 위해서는 같은 도로 상의 궤적들을 모으는 방법이 필요하다. 흔히 프레셰 거리($Fr{\acute{e}}chet$ distance)가 궤적 쌍의 거리를 측정하는데 사용된다. 하지만 프레셰 거리는 대량의 궤적들에 대해서는 계산 시간의 소모가 심하다. 본 논문에서는 궤적들의 인접성 여부를 이산프레셰 거리를 통해 빠르게 구분하는 휴리스틱 알고리즘을 제안한다. 이 알고리즘은 계산되는 거리의 정확도를 낮추는 대신 계산 속도를 높였다. 실험 결과, 제안 방법은 이산 프레셰 거리 대비 95%의 정확도와 최하 65%의 계산 감소율로 거리가 10m 이내인 궤적들을 구분할 수 있었다.

• 대한수학회논문집
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• 제13권2호
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• pp.359-365
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• 1998

We give two sufficient conditions that the space (X,C*) be a Fr$\acute{e}$chet-Urysohn space such that $x_n \to x$ in (X,c) if and only if $x_n \to x$ in (X,c*), where c* is the sequential closure operator on a generalized topological (X,c).

• East Asian mathematical journal
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• 제24권1호
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• pp.97-103
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• 2008

New fixed point theorems for permissible maps between $Fr{\acute{e}}chet$ spaces are presented. The proof relies on index theory developed by Dzedzej and on viewing a $Fr{\acute{e}}chet$ space as the projective limit of a sequence of Banach spaces.

• 대한수학회논문집
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• 제24권1호
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• pp.145-152
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• 2009

In this paper, we introduce a new property of a topological space which is weaker than sequential compactness and give some necessary and sufficient conditions for a $Fr{\acute{e}}chet$-Urysohn space with the property to be sequentially compact.

• 충청수학회지
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• 제24권3호
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• pp.401-407
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• 2011

The paper deals with characterization of standard Gumbel distribution and standard $Fr{\acute{e}}chet$ distribution and was motivated by [4], where the Weibull distribution is characterized. We present criterions using the independence of some suitable functions of lower records in a sequence of independent identically distributed random variables $\{X_n,\;n{\geq}1\}$.