• Bulletin of the Korean Mathematical Society
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• v.60 no.1
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• pp.161-170
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• 2023

We consider dual Toeplitz operators acting on the orthogonal complement of the Dirichlet space on the unit disk. We give a characterization of when a finite sum of products of two dual Toeplitz operators is equal to 0. Our result extends several known results by using a unified way.

• Bulletin of the Korean Mathematical Society
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• v.46 no.5
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• pp.967-978
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• 2009

In this work, we give some characterizations of rectifying curves in dual Lorentzian space. Also, we show that rectifying dual Lorentzian curves can be stated by the aid of dual unit spherical curves.

• Journal of the Chungcheong Mathematical Society
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• v.24 no.1
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• pp.137-140
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• 2011

It is known [5] that the concepts of $C_k$-spaces and those can be characterized using by the Gottlieb sets and the LS category of spaces as follows; A space X is a $C_k$-space if and only if the Gottlieb set G(Z, X) = [Z, X] for any space Z with cat $Z{\leq}k$. In this paper, we introduce a dual concept of $C_k$-space and obtain a dual result of the above result using the dual Gottlieb set and the dual LS category.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.11
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• pp.1102-1110
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• 2006

This paper addresses the problem of computing grasp stability of the object for two-fingered robots in two dimensions. The concepts of force-closure and dual space are introduced and discussed in novel point of view, and we transform friction cones in a robot work space to line segments in a dual space. We newly define a grasp stability index by calculating intersection condition between line segments in dual space. Moreover, we propose a method to find the optimal grasp points of the given object by comparing the defined grasp stability index. Its validity and effectiveness are investigated and verified by simulations for quadrangle object and elliptic objects.

• Honam Mathematical Journal
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• v.42 no.1
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• pp.187-195
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• 2020

In this paper, we investigate the vectorial moments of Bäcklund transformations of a space curve in 𝔼³. Firstly, it is obtained the vectorial moments which named α𝓖 dual curve, β𝓖 dual curve, and γ𝓖 dual curve of Bäcklund transformations. Then we give the Euler elastic bending energies of these curves. Finally, we provide some examples of α𝓖 dual, β𝓖 dual, and γ𝓖 dual, and their Euler elastic bending energies.

• Bulletin of the Korean Mathematical Society
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• v.39 no.1
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• pp.133-140
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• 2002

On compact complex hyperbolic manifolds of complex dimension two, we show that the dimension of the space of infinitesimal deformations of self-dual conformal structures is smaller than that of the deformation obstruction space and that every self-dual metric with covariantly constant Ricci tensor must be a standard one upto rescalings and diffeomorphisms.

• Honam Mathematical Journal
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• v.41 no.1
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• pp.185-195
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• 2019

In this work, we study the conditions between null geodesic curves and timelike ruled surfaces in dual Lorentzian space. For this study, we establish a system of differential equations characterizing timelike ruled surfaces in dual Lorentzian space by using the invariant quantities of null geodesic curves on the given ruled surfaces. We obtain the solutions of these systems for special cases. Regarding to these special solutions, we give some results of the relations between null geodesic curves and timelike ruled surfaces in dual Lorentzian space.

• Korean Journal of Mathematics
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• v.6 no.2
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• pp.341-348
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• 1998

In this paper, we show that Schlumprecht space is reflexive and the Dual of Schlumprecht space has the Banach-Saks property and study behavior of block basic sequence in Schlumprecht space.

• Honam Mathematical Journal
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• v.44 no.4
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• pp.618-627
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• 2022

On the setting of the orthogonal complement of the weighted Bergman space, we study the problem of when a finite sum of dual Toeplitz products is compact or zero. Our results extend several known results on the unweighted space to the weighted spaces.

• Journal of Families and Better Life
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• v.23 no.6 s.78
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• pp.1-13
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• 2005

The aim of this study is to investigate the housework space viewed from housewives and husband in dual-earner families. For this study, depth-interview method were used to collects the data. The depth-interview were conducted on the eight heusewives and two husbands in dual-earner families in Jinju and Gwangju in April 2005. The narratives were then analyzed to discover the demands of the kitchen and laundry room. The major results were as follows: 1) Dual-earner families want the kitchen design is they can share housework with their spouses, such as kitchen facing the front side of the floor plan and island counter. In addition, they want spacious, adjustable(flexible), visible storage to enable the housewives to work with their spouse efficiently. Space for Kimchi refrigerator should be considered in the kitchen. 2) They want the noise-free laundry because the interviewers did their laundry work in the night time. Also, they want a multi-purpose laundry mm where machine washing, hand washing, drying and ironing can be done. In addition, for hand-washing wives and husbands, specific space and facilities where they can hand washing on stand posture were needed.