• 호남수학학술지
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• 제33권1호
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• pp.85-91
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• 2011

We introduce and investigate the notions of super (g,g')-continuous functions and strongly $\theta$(g,g')-continuous functions on generalized topological spaces, which are strong forms of (g,g')-continuous functions. We also investigate relationships among such the functions, (g,g')-continuity and (${\delta},{\delta}'$)-continuity.

• 충청수학회지
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• 제25권3호
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• pp.401-413
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• 2012

In the present paper we construct and introduce a new topology from an old one which are independent each of the other. The members of this topology are called ${\omega}_{\delta}$-open sets. We investigate some basic properties and their relationships with some other types of sets. Furthermore, a new characterization of regular and semi-regular spaces are obtained. Also, we introduce and study some new types of continuity, and we obtain decompositions of some types of continuity.

• 대한수학회논문집
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• 제27권2호
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• pp.357-368
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• 2012

We introduce the concepts of fuzzy ${\delta}$-interior and show that the set of all fuzzy ${\delta}$-open sets is also a fuzzy topology, which is called the fuzzy ${\delta}$-topology. We obtain equivalent forms of fuzzy ${\delta}$-continuity. More-over, the notions of fuzzy ${\delta}$-compactness and fuzzy locally ${\delta}$-compactness are defined and their basic properties under fuzzy ${\delta}$-continuous mappings are investigated.

• 대한수학회보
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• 제22권1호
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• pp.17-22
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• 1985

B.M. Munshi and D.S. Bassan defined and developed the concept of super continuity in [5]. The concept has been investigated further by I. L. Reilly and M. K. Vamanamurthy in [6] where super continuity is characterized in terms of the semi-regularization topology. Super continuity is related to the concepts of .delta.-continuity and strong .theta.-continuity developed by T. Noiri in [7]. The purpose of this note is to derive relationships between super continuity and other strong continuity conditions and to develop additional properties of super continuous functions. Super continuity implies continuity, but the converse implication is false [5]. Super continuity is strictly between strong .theta.-continuity and .delta.-continuity and strictly between complete continuity and .delta.-continuity. The symbols X and Y will denote topological spaces with no separation axioms assumed unless explicity stated. The closure and interior of a subset U of a space X will be denoted by Cl(U) and Int(U) respectively and U is said to be regular open (resp. regular closed) if U=Int[Cl(U) (resp. U=Cl(Int(U)]. If necessary, a subscript will be added to denote the space in which the closure or interior is taken.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제1권1호
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• pp.69-74
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• 2001

We introduce fuzzy semi-regular spaces. Furthermore, we investigate the relations among fuzzy super continuity, fuzzy $\delta$-continuity and fuzzy almost continuity in fuzzy topological spaces in view of the definition of Sostak. We study some properties between them.

• Kyungpook Mathematical Journal
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• 제46권1호
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• pp.119-130
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• 2006

A new class of functions is introduced in this paper. This class is called almost ${\delta}$-precontinuity. This type of functions is seen to be strictly weaker than almost precontinuity. By using ${\delta}$-preopen sets, many characterizations and properties of the said type of functions are investigated.

• 호남수학학술지
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• 제29권4호
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• pp.597-615
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• 2007

The aim of this paper is to introduce the class of ${\delta}gs$-closed sets and obtain characterizations of almost weakly Hausdorff spaces due to Dontchev and Ganster. We also introduce the notion of ${\delta}gs$-continuity and investigate the relationships between it and other types of continuity.

• 대한수학교육학회지:수학교육학연구
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• 제27권4호
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• pp.727-745
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• 2017

본 연구는 함수의 연속성에 대한 학문수학의 개념과 학생들의 인식의 차이를 탐구하기 위해, 아리스토텔레스의 연속 개념 및 함수의 연속성의 역사적 발달과정을 고찰하였다. 연속의 본질을 찾고자 했던 아리스토텔레스는 연속을 '분할 불가능한 하나의 전체'로 특징지었다. 19세기 이전 수학자들은 공간에 기초하여 함수의 연속성을 생각하였지만, 19세기 해석학의 산술화 이후 연속 개념은 현대적인 ${\epsilon}-{\delta}$ 정의로 나타났으며, 여러 학자들은 이 과정을 혁명적이라고 생각하였다. 학생들은 아리스토텔레스의 연속 개념 및 산술화 이전 수학자들과 유사한 관점으로 함수의 연속성을 생각하는 경향이 있었으며, 따라서 학생들의 개념을 단순히 오류로 보는 것은 무리가 있다. 함수의 연속성에 대한 본 연구는, 학생들의 오개념으로 인지되고 있는 것들은 때때로 오류라기보다는 역사적으로 존재해왔던 하나의 패러다임적 사고로서 볼 수 있음을 고찰하였다.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2003년도 추계학술대회 논문집
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• pp.39-42
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• 2003

Leading edge extension(LEX) in a highly swept shape applied to a delta wing features the modern air-fighters. The LEX vortices generated upon the upper surface of the wing at high angle of attack enhance the lift force of the delta wing by way of increased negative suction pressure over the surfaces. The present 3-D stereo PIV includes the Identification of 2-D cross-correlation equation, stereo matching of 2-D velocity vectors of two cameras, accurate calculation of 3-D velocity vectors by homogeneous coordinate system, removal of error vectors by a statistical method followed by a continuity equation criterion and so on. A delta wing model with or without LEX was immersed in a circulating water channel. Two high-resolution, high-speed digital cameras$(1280pixel\times1024pixel)$ were used to allow the time-resolved animation work. The present dynamic stereo PIV represents the complicated vortex behavior, especially, in terms of time-dependent characteristics of the vortices at given measuring sections. Quantities such as three velocity vector components, vorticity and other flow information can be easily visualized via the 3D time-resolved post-processing to make the easy understanding of the LEX effect or vortex emerging and collapse which are important phenomena occurring in the field of delta wing aerodynamics.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.1672-1677
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• 2004

Leading edge extension(LEX) in a highly swept shape applied to a delta wing features the modem air-fighters. The LEX vortices generated upon the upper surface of the wing at high angle of attack enhance the lift force of the delta wing by way of increased negative suction pressure over the surfaces. The present 3-D stereo PIV includes the Identification of 2-D cross-correlation equation, stereo matching of 2-D velocity vectors of two cameras, accurate calculation of 3-D velocity vectors by homogeneous coordinate system, removal of error vectors by a statistical method followed by a continuity equation criterion and so on. A delta wing model with or without LEX was immersed in a circulating water channel. Two high-resolution, high-speed digital cameras($1280pixel{\times}1024pixel$) were used to allow the time-resolved animation work. The present dynamic stereo PIV represents the complicated vortex behavior, especially, in terms of time-dependent characteristics of the vortices at given measuring sections. Quantities such as three velocity vector components, vorticity and other flow information can be easily visualized via the 3D time-resolved post-processing to make the easy understanding of the LEX effect or vortex emerging and collapse which are important phenomena occurring in the field of delta wing aerodynamics.