• 호남수학학술지
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• 제45권1호
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• pp.1-24
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• 2023

In the present paper, we prove common fixed point theorems for a pair of weakly compatible mappings under implicit contractive relation in quasi-partial S_b-metric spaces. We also provide an illustrative example to support our results. Furthermore, we will use the results obtained for application to two boundary value problems for the second-order differential equation. Also, we prove a common solution for the nonlinear fractional differential equation.

• 대한수학회보
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• 제47권3호
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• pp.443-454
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• 2010

In this paper, we investigate the zeros distribution and Borel direction for the solutions of linear homogeneous differential equation $f^{(n)}+A_{n-2}(z)f^{(n-2)}+{\cdots}+A_1(z)f'+A_0(z)f=0(n{\geq}2)$ in an angular domain. Especially, we establish a relation between a cluster ray of zeros and Borel direction.

• 대한수학회보
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• 제46권3호
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• pp.463-475
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• 2009

This paper deals with the regularity properties for a class of semilinear integrodifferential functional differential equations. It is shown the relation between the reachable set of the semilinear system and that of its corresponding linear system. We also show that the Lipschitz continuity and the uniform boundedness of the nonlinear term can be considerably weakened. Finally, a simple example to which our main result can be applied is given.

• East Asian mathematical journal
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• 제19권1호
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• pp.133-150
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• 2003

This paper will show that the relation (1.1) $$L^1({\Omega}){\subset}C_0(\bar{\Omega}){\subset}H_{p,q}$$ if 1/p'-1/n(1-2/q')<0 where p'=p/(p-1) and q'=q/(q-1) where $H_{p.q}=(W^{1,p}_0,W^{-1,p})_{1/q,q}$. We also intend to investigate the control problems for the retarded systems with $L^1(\Omega)$-valued controller in $H_{p,q}$.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제25권4호
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• pp.629-639
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• 2011

최근 공과대학 학생들에게 대학수학의 중요성이 부각되고 있는 반면, 제7차 수학과교육과정의 인문계 수학에는 미분적분이 포함되어 있지 않고, 많은 중위권 대학의 입학전형에서 교차지원을 허용하기 때문에 공과대학 대학수학의 교수학습에서 많은 어려움이 발생한다. 본 연구에서는 중위권 공과대학 신입생들의 수학 기초학력과 대학수학능력시험수리영역 성적의 관계를 조사하여 교차지원을 허용하는 입학전형 제도의 문제점을 실증적으로 밝히는데 그 의의를 두었으며, 이를 위하여 2010학년도 A대학교 공과대학 신입생들을 대상으로 대학수학능력시험 수리영역 성적과 수학 기초학력평가 및 대학수학 교과목의 성적을 비교 분석하였다.

• Korean Journal of Mathematics
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• 제18권4호
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• pp.343-356
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• 2010

We define a G-fuzzy congruence, which is a generalized fuzzy congruence, discuss some of its basic properties, and characterize the G-fuzzy congruence generated by a fuzzy relation on a semigroup. We also give certain lattice theoretic properties of G-fuzzy congruences on semigroups.

• Korean Journal of Mathematics
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• 제25권4호
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• pp.563-577
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• 2017

We define a weak fuzzy equivalence relation and a weak fuzzy congruence and develop some properties of the weak fuzzy equivalence relations and the weak fuzzy congruences on semigroups.

• Korean Journal of Mathematics
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• 제8권2호
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• pp.187-191
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• 2000

In the present paper we shall first introduce the timewidth of a signal, and then we shall investigate the relation between the timewidths of a signal $f$ and of the convolution $f*h$ for some other signal $h$.

• Korean Journal of Mathematics
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• 제22권4호
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• pp.683-691
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• 2014

We redefine a fuzzy congruence, discuss some properties of the fuzzy congruences, find the fuzzy congruence generated by a fuzzy relation on a semigroup, and give some lattice theoretic properties of the fuzzy congruences on semigroups.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제18권2호
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• pp.9-33
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• 2004

The purpose of this paper is to contribute to the dialogue about the notion of advanced mathematical thinking by offering an alternative characterization for this idea, namely advancing mathematical activity. We use the term advancing (versus advanced) because we emphasize the progression and evolution of students' reasoning in relation to their previous activity. We also use the term activity, rather than thinking. This shift in language reflects our characterization of progression in mathematical thinking as acts of participation in a variety of different socially or culturally situated mathematical practices. We emphasize for these practices the changing nature of student' mathematical activity and frame the process of progression in terms of multiple layers of horizontal and vertical mathematizing.