• 대한수학회보
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• 제50권6호
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• pp.1923-1936
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• 2013

We prove that the intrinsic square functions including Lusin area integral and Littlewood-Paley $g^*_{\lambda}$-function as defined by Wilson, are bounded in a class of function spaces include weighted Morrey spaces. The corresponding commutators generated by BMO functions are also considered.

• Journal of applied mathematics & informatics
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• 제13권1_2호
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• pp.487-500
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• 2003

We investigate categorical relationships between the category of smooth fuzzy topological spaces, the category of intuitionistic fuzzy topological spaces, and the category of intuitionistic fuzzy topological spaces, and the category of intuitioistic fuzzy topological spaces in Sostak's sense.

• Journal of applied mathematics & informatics
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• 제30권5_6호
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• pp.729-740
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• 2012

In this paper, we prove common fixed point theorems for occasionally weakly compatible maps in Menger spaces with a continuous t-norm of H-type. As application to our results, we obtain the corresponding fixed point theorems in metric spaces. Our results improve and generalize many known results in Menger spaces as well as in metric spaces.

• 대한수학회논문집
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• 제27권1호
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• pp.137-148
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• 2012

Recently Ding [4, 5, 8] gives examples of his FC-spaces which are not L-spaces due to Ben-El-Mechaiekh et al. [1]. We show that they are actually L-spaces. We also clarify that all statements in [5] can be stated in corrected and generalized forms for the class of abstract convex spaces beyond FC-spaces.

• 충청수학회지
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• 제27권3호
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• pp.439-454
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• 2014

We deal with the boundedness of the n-th derivatives of Bloch-type functions and Toeplitz operators and give a relationship between Bloch-type spaces and ranges of Toeplitz operators. Also we prove that the vanishing property of ${\parallel}uk^{\alpha}_z{\parallel}_{s,{\alpha}}$ on the boundary of $\mathbb{D}$ implies the compactness of Toeplitz operators and introduce a generalization of Bloch-type spaces.

• 대한수학회보
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• 제56권6호
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• pp.1569-1575
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• 2019

In this paper we calculate three geometric constants, namely the von Neumann-Jordan constant, the James constant, and the Dunkl-Williams constant, for Morrey spaces and discrete Morrey spaces. These constants measure uniformly nonsquareness of the associated spaces. We obtain that the three constants are the same as those for $L^1$ and $L^{\infty}$ spaces.

• Korean Journal of Mathematics
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• 제29권2호
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• pp.211-225
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• 2021

In the present paper we introduce some sequence spaces over n-normed spaces defined by fractional difference operator and Musielak-Orlicz function 𝓜 = (𝕱_i). We also study some topological properties and prove some inclusion relations between these spaces.

• 충청수학회지
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• 제23권3호
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• pp.589-598
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• 2010

Generalizing normally quasi-ordered spaces, we introduce a concept of regularly quasi-ordered spaces and study their categorical properties. We obtain well behaved reflective subcategories of the category Rqos of regularly quasi-ordered spaces and continuous isotones, namely the full subcategory of Rqos determined by $T_0$-objects among others, and this result can be extended to that in the category Nqos of normally quasi-ordered spaces and continuous isotones.

• Nonlinear Functional Analysis and Applications
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• 제29권1호
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• pp.295-306
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• 2024

In this work, we investigate the generalized Hyers-Ulam stability of quadratic functional inequality in modular spaces satisfying ∆₂-conditions and Fatou property, and in 𝛽-homogeneous Banach spaces.

• 한국환경보건학회지
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• 제30권5호
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• pp.353-357
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• 2004

The purpose of this research is to characterize formaldehyde as trace toxic air pollutant in the underground spaces in Gyungnam province. Air samples of formaldehyde were taken in the three underground spaces for ten months from April 2003 to January 2004. The IAQ(Indoor Air Quality) of underground spaces were controled using central ventilation(supply/exhaust) system. The levels of GM of airborne formaldehyde concentrations in three sampling spaces were well below applicable standards, Korean Ministry of Environment, 0.1 ppm. However, some sample of airborne formaldehyde concentrations in underground spaces 'B' and 'C' were in excess of standard, due to the commercial products in shop, structural material, and the climate having high humidity and temperature. There are statistical differences in levels of formaldehyde by sampling spaces (p=0.086).