• 제어로봇시스템학회:학술대회논문집
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• 1995.10a
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• pp.468-471
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• 1995

In this paper, we propose a new strategy for a space robot to control its attitude. A space robot is an example of a class of non-holonomic systems, a system of which cannot be stabilized into its equilibria with continuous static state feedbacks even in the case that the system is, in some sense, controllable. Thus, we cannot design stabilizing controllers for space robots using conventional control theories. The strategy presented here transforms the non-holonomic system into a time-state control form, and allows us to make the state of the original system any desired one. In the stabilization, any conventional control theory can be applied. For simplicity, a space robot with a two-link manipulator is considered, and a simulated motion of the controlled system is shown.

• Kyungpook Mathematical Journal
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• v.28 no.1
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• pp.91-95
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• 1988

The nature of a H-set in a Hausdorff space is not well understood. In this note it is shown that if X is a countable union of nowhere dense compact sets, then X is not H-embeddable in any Hausdorff space. An example is given to show that there exists a non-Urysohn, non-H-closed space X such that each H-set of X is compact.

• Korean Institute of Interior Design Journal
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• v.25 no.5
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• pp.157-166
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• 2016

This study is intended to examine the various kinds of emptiness that are shown in the empty spaces created by Hyo-Sang Seung and Louis I. Kahn. Architecture creates the usefulness of a certain space thanks to its emptiness. The word, 'Emptiness' has the following meanings, 'non-fulfillment', 'non-existence', 'emptiness', 'blankness', 'non-visibility' and 'non-limitation', etc. Such concepts of emptiness can be broadly divided into 'ideological emptiness', 'aesthetic' and 'architectural spatial'. Comparisons regarding such concepts of emptiness as they are expressed in the architectural spaces created by Hyo-sang Seung and Louis I. Kahn shall be identified in this study. Hyo-sang Seung tried to leave numerous open possibilities which can contain everything into a certain space since 'emptiness' is not being used at this moment. Louis I. Kahn tried to contain into a space the essence and silence of that space before something that exists is created. The 'emptiness' created by Hyo-sang Seung and Louis I. Kahn is a specific space which can contain more kinds of non-visible spaces than some visible ones. Thus, such spaces may contain various potentials which are possible because they are empty, because of changes in nature and time, and because of silence and intentions going beyond an artist's original intent.

• Bulletin of the Korean Mathematical Society
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• v.52 no.4
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• pp.1339-1351
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• 2015

In this paper, using pseudo-spherical Frenet frame of pseudo-spherical curves in hyperbolic space, we define the notion of the structure functions on the non-developable ruled surfaces with timelike ruling. Then we obtain the properties of the structure functions and a complete classification of the non-developable ruled surfaces with timelike ruling in Minkowski 3-space by the theories of the structure functions.

• Journal of applied mathematics & informatics
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• v.34 no.5_6
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• pp.509-517
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• 2016

In this paper, we consider the following functional equation with involution f(x + y) + f(x + σ(y)) = 2f(x) + f(y) + f(σ(y)) and prove the generalized Hyers-Ulam stability for it when the target space is a non-Archimedean Banach space.

• Journal of Information Processing Systems
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• v.12 no.4
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• pp.591-611
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• 2016

High dimensional space is the biggest problem when classification process is carried out, because it takes longer time for computation, so that the costs involved are also expensive. In this research, the facial space generated from homogeneous and non-homogeneous polynomial was proposed to extract the facial image features. The homogeneous and non-homogeneous polynomial-based eigenspaces are the second opinion of the feature extraction of an appearance method to solve non-linear features. The kernel trick has been used to complete the matrix computation on the homogeneous and non-homogeneous polynomial. The weight and projection of the new feature space of the proposed method have been evaluated by using the three face image databases, i.e., the YALE, the ORL, and the UoB. The experimental results have produced the highest recognition rate 94.44%, 97.5%, and 94% for the YALE, ORL, and UoB, respectively. The results explain that the proposed method has produced the higher recognition than the other methods, such as the Eigenface, Fisherface, Laplacianfaces, and O-Laplacianfaces.

• Investigative Magnetic Resonance Imaging
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• v.22 no.4
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• pp.229-239
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• 2018

Purpose: To assess the diagnostic performance in detecting rotator cuff tears at 3T of non-arthrographic shoulder magnetic resonance imaging (MRI) using 3D isotropic turbo spin-echo (TSE-SPACE) sequence as compared with 2D sequences. Materials and Methods: Seventy-four patients who were arthroscopically confirmed to have underwent non-arthrographic shoulder MRI with 2D sequences and TSE-SPACE were included. Three independent readers retrospectively scored supraspinatus and infraspinatus tendon (SST-IST) and subscapularis tendon (SCT) tears on 2D sequences and TSE-SPACE. Results: The mean sensitivity, specificity, and accuracy of the three readers were 95%, 100%, and 95% on TSE-SPACE and 99%, 93%, and 98% on 2D sequences for detecting SST-IST tears, respectively, whereas those were 87%, 49%, and 68% on TSESPACE and 88%, 66%, and 77% on 2D sequences for detecting SCT tears, respectively. There was no statistical difference between the two sequences, except for in the specificity of one reader for detecting SCT tears. The mean AUCs of the three readers on TSE-SPACE and 2D sequences were 0.96 and 0.98 for detecting SST-IST tears, respectively, which were not significantly different, while those were 0.71 and 0.82 for detecting SCT tears, respectively, which were significantly different (P < 0.05). Conclusion: TSE-SPACE may have accuracy and reliability comparable to conventional 2D sequences for SST-IST tears at non-arthrographic 3T shoulder MRI, whereas TSE-SPACE was less reliable than conventional 2D sequences for detecting SCT tears.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2007.04a
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• pp.259-264
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• 2007

In this paper, to analyze the initial valued non-homogeneous elastic half space by the scaled boundary analysis, the infinite element approach was introduced. The free surface of the initial valued non-homogeneous elastic half space was mode1ed as a circumferential direction of boundary scaled boundary coordinate. The infinite element was used to represent the infinite length of the free surface. The initial value of material property(elastic modulus) was considered by the combination of the position of the sealing center and the power function of the radial direction. By use of the mapping type infinite element, the consistent e1ements formulation could be available. The performance and the feasibility of proposed approach are examined by two numerical examples.

• Journal of Oral Medicine and Pain
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• v.18 no.1
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• pp.21-29
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• 1993

The purpose of this study was to evaluation of temporomandibulr joint space according to increasing the occlusal force on working and non-working side during unilateral bite. For the study, 22 normal adults, age ranged from 23 to 25, who had no symptoms on TMJ area and masticatory muscles and had normal or class I molar relationship were selected. Transcranial TMJ radiograph was taken during unilateral biting with sensor of Bite force checker (Nihon Kohden Kygyo Co.Ltd., Japan) on each 1st molar teeth of right and left side which were forced each 0Kg, 10Kg, 20Kg and 30Kg by use of Accurad-200 (Denar Corperation's product). The radiographs were traced on the screen, which was magnified by 5. The size of temporomandibular joint space at anterior, superior and posterior compartment were measured with Dumas's method (reference line of between squamotympanic fissure and the most inferior point of articular eminence). On the basis of this study, the following results were obtained. 1. Size of anterior TMJ space was tend to decrease on the working side and increase on the non-working side according to increasing the occlusal force, but not significant statistically (p>0.05). 2. Size of superior TMJ space was tend to increase on the working side and decrease on the non-working side according to increasing the occlusal force (p<0.05). 3. Size of posterior TMJ space was tend to decrease on both working ad nonworking side, but non significant statistically.

• East Asian mathematical journal
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• v.31 no.3
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• pp.337-344
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• 2015

We study screen quasi-conformal irrotational half lightlike submanifolds M of a semi-Riemannian space form $\bar{M}$ (c) equipped with a semi-symmetric non-metric connection subject such that the structure vector field of $\bar{M}$ (c) belongs to the screen distribution S(TM). The main result is a non-existence theorem for such half lightlike submanifolds.