• Journal of the Korean Mathematical Society
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• v.33 no.1
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• pp.145-154
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• 1996

In the study of manifold decompositions, a central theme is to understand the source manifold taking advantage of the informations of a base space and a decomposition. The concepts of both Hurewicz fibrations and cell-like maps have played very important roles for investigating the mutual relations of three objects. But it is somewhat restrictive for a decomposition map to be cell-like because its inverse images must have trivial shapes.

• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.143-150
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• 2004

In this paper we study the estimation problem of individual weights of objects using an A-optimal chemical balance weighing design. We assume that in this model errors are correlated and they have the same variances. The lower bound of tr$(X'G^{-1}X)^{-1}$ is obtained and a necessary and sufficient condition for this lower bound to be attained is given. There is given new construction method of A-optimal chemical balance weighing design.

• Communications of Mathematical Education
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• v.18 no.3 s.20
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• pp.117-126
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• 2004

Breidenbach et al(1992)는 APOS(Actions, Processes, Objects, Schemas)를 소개하였고 Sfard(1991)는 수학적 개념에서의 Process 와 Object의 상호관련성에 대해서 발표하였다. 본 연구자는 이 이론들을 기반으로 초등학생(4$^{\sim}$6학년)과 중등 영재학생(1학년)을 대상으로 하여 조한혁의 JavaMAL Logo를 이용한 실험을 실행하였다. 이 실험에서는 Process와 Object의 의미와 이 개념들 간의 상호관계를 분석하였고 이러한 관계가 학생들의 창의성에 어떠한 영향을 끼치는지 비교분석하였다.

• Journal for History of Mathematics
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• v.24 no.1
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• pp.63-73
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• 2011

This paper analyses conceptual change from Euclid's dictionary definition to Hilbert's mathematical definition about primitive terms in Geometry. Realism, conceptualism, nominalism about mathematical objects are related to this conceptual change.

• Journal of the Korean Mathematical Society
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• v.38 no.4
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• pp.723-761
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• 2001

The objects of this paper are to formulated a model for the transport of a chain of radioactive waste products in a fractured porous medium, to devise an effective and efficient numerical method for approximating the solution of the model, and to demonstrated the convergence of the numerical method. The formulation begins from a model in an unfractured (single porosity) medium, passes through a double porosity model in a fractured medium, and ends with a modified single porosity model that takes the relevant time scales of the flow and the nuclear decay.

• Bulletin of the Korean Mathematical Society
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• v.53 no.2
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• pp.551-559
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• 2016

Recently a construction of local cohomology functors for compactly generated triangulated categories admitting small coproducts is introduced and studied by Benson, Iyengar, Krause, Asadollahi and their coauthors. Following their idea, we introduce the depth of objects in such triangulated categories and get that when (R, m) is a graded-commutative Noetherian local ring, the depth of every cohomologically bounded and cohomologically finite object is not larger than its dimension.

• Journal of the Korean Mathematical Society
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• v.56 no.4
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• pp.1031-1048
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• 2019

In this paper we study recollements of abelian categories and balanced pairs. The main results are: recollements induce new balanced pairs from the middle category; the resolution dimensions are bounded under certain conditions. As an application, the resolution dimensions with respect to cotilting objects of abelian categories involved in recollements are recovered.

• Journal of the Chungcheong Mathematical Society
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• v.23 no.3
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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.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.18 no.3
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• pp.225-244
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• 2014

In this work, we discuss segmentation algorithms based on the level set method that incorporates shape prior knowledge. Fundamental segmentation models fail to segment desirable objects from a background when the objects are occluded by others or missing parts of their whole. To overcome these difficulties, we incorporate shape prior knowledge into a new segmentation energy that, uses global and local image information to construct the energy functional. This method improves upon other methods found in the literature and segments images with intensity inhomogeneity, even when images have missing or misleading information due to occlusions, noise, or low-contrast. We consider the case when the shape prior is placed exactly at the locations of the desired objects and the case when the shape prior is placed at arbitrary locations. We test our methods on various images and compare them to other existing methods. Experimental results show that our methods are not only accurate and computationally efficient, but faster than existing methods as well.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.9
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• pp.104-113
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• 1996

In robot system, the robot manipulation needs the information of task and objects to be handled in possessing a variaty of positions and orientations. In the current industrial robot system, determining position and orientation of objects under industrial environments is one of major problems. In order to pick up an object, the roblt needs the information about the position and orientation of object, and between objects and gripper. When sensing is accomplished by pinhole model camera, the mathematical relationship between object points and their images is expressed in terms of perspective, i.e., central projection. In this paper, a new approach to determine the information of the supporting points related to position and orientation of the object using the robot vision system is developed and testified in experimental setup. The result will be useful for the industrial, agricultural, and autonomous robot.