• Journal of the Chungcheong Mathematical Society
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• v.31 no.4
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• pp.421-427
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• 2018

The aim of this study is to investigate the prolongations of G-structures immersed in the generalized almost r-contact structure on a manifold M to its tangent bundle T(M) of order 2. Moreover, theorems on Hsu structure, integrability and (${F\limits^{\circ}},\;{{\xi}\limits^{\circ}}{{\omega}\limits^{\circ}}_p,\;a,\;{\epsilon}$)-structure have been established.

• Journal of the Korean Society of Safety
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• v.31 no.5
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• pp.102-108
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• 2016

This paper presents a new strength method of underground box structures under additional surface load. An L-bracing using pre-flexed steel member threads called the "Pre-flex strength method" is used to improve capacity of the RC box structure under earth pressure due to additional surface load. The pre-flexed steel member is fixed the top and bottom of the structure after chemical anchor was installed by drilling hole on the box structure. The structural performance was evaluated analytically. 3 types of underground RC box structure were used; $2.0m{\times}2.0m$, $3.0m{\times}3.0m$ and $4.0m{\times}4.0m$. For the performance evaluation, structure analysis were performed on moment and shear resisting structures with and without pre-flex strength method. Numerical results confirmed that the proposed strength member system installed on underground RC box structures enhanced the strength capacity. The feasible region of the proposed pre-flex strength method in accordance with the earth pressure due to additional surface depth was evaluated.

• Honam Mathematical Journal
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• v.27 no.3
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• pp.487-504
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• 2005

Let M be a real hypersurface with almost contact metric structure (${\phi}$, ${\xi}$, ${\eta}$, g) in a nonflat complex space form $M_n(c)$. We denote by A and S be the shape operator and the Ricci tensor of M respectively. In the present paper we investigate real hypersurfaces with $g(SA{\xi},\;A{\xi})=const$. of $M_n(c)$ whose structure Jacobi operator $R_{\xi}$ commute with both ${\phi}$ and S. We give a characterization of Hopf hypersurfaces of $M_n(c)$.

• Communications of the Korean Mathematical Society
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• v.34 no.2
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• pp.615-632
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• 2019

We study generic lightlike submanifolds M of an indefinite trans-Sasakian manifold ${\bar{M}}$ or an indefinite generalized Sasakian space form ${\bar{M}}(f_1,f_2,f_3)$ endowed with an $({\ell},m)$-type metric connection subject such that the structure vector field ${\zeta}$ of ${\bar{M}}$ is tangent to M.

• Bulletin of the Korean Mathematical Society
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• v.60 no.3
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• pp.717-732
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• 2023

The goal of this paper is to analyze the generalized m-quasi-Einstein structure in the context of almost Kenmotsu manifolds. Firstly we showed that a complete Kenmotsu manifold admitting a generalized m-quasi-Einstein structure (g, f, m, λ) is locally isometric to a hyperbolic space ℍ²ⁿ⁺¹(-1) or a warped product ${\tilde{M}}{\times}{_{\gamma}{\mathbb{R}}$ under certain conditions. Next, we proved that a (κ, µ)'-almost Kenmotsu manifold with h' ≠ 0 admitting a closed generalized m-quasi-Einstein metric is locally isometric to some warped product spaces. Finally, a generalized m-quasi-Einstein metric (g, f, m, λ) in almost Kenmotsu 3-H-manifold is considered and proved that either it is locally isometric to the hyperbolic space ℍ³(-1) or the Riemannian product ℍ²(-4) × ℝ.

• Journal of Advanced Navigation Technology
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• v.21 no.1
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• pp.132-137
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• 2017

This paper proposes a transformation method of the zero moment point (ZMP) and the center of mass (CoM) from one walking pattern to other patterns by considering the structure of a robot or walking situations in real time. In general, a humanoid robot has own structure characteristics like height and mass. The structure characteristics make the given CoM/ZMP walking pattern of one human or one humanoid robot to be difficult to apply to other robot directly. For this purpose, we analyze the characteristics of walking patterns according to the step length, duration of walking support phase and the CoM height by using the cart-table model as the simple humanoid robot model. A transformation equation is derived from the analyzation and it is verified with simulation.

• Journal of the Korean Ceramic Society
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• v.23 no.5
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• pp.25-34
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• 1986

This study was to refined the crystal structure of solid solution to determine the position and amount of Al in diopside and to relate crystal structure changes and properties of solid solution. Single crystals of the solid solution in the system CaO.MgO.$2 SiO_2-Al_2O_3$ were made from the melt with slow cooling and used to refine the structure. The following were obtained. 1. Tetrahedra rotated around axis parallel to the direction which the angle 03-03-03 became small. 2. Tetrahedron became large and regular. Average T-O bond distance increased 0.53 percent. 3. M1 octahedron became small and average M1-O bond distance decreased 1.1 percent. 4, M2 polyhedron became small and average M2-O bond distance decreased 0.37 percent Polythedron was affected not so much compared with any cation site. 5. Distance between metal ions distances between T and oxygens which were coordinated with M2 and meighboring tetrahedron distances between M2 and oxygens which coordinated with M1 and M2 were not changed almost. 6. $Al^{3+}$ substituted 4Mg^{2+}$ and $Si^{4+}$

• ETRI Journal
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• v.31 no.6
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• pp.642-646
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• 2009

Highly efficient white phosphorescent organic light-emitting diodes with a mixed-host structure are developed and the device characteristics are studied. The introduction of a hole-transport-type host (N, N'-dicarbazolyl-3-3-benzen (mCP)) into an electron-transport-type host (m-bis-(triphenylsilyl)benzene (UGH3)) as a mixed-host emissive layer effectively achieves higher current density and lower driving voltage. The peak external quantum and power efficiency with the mixed-host structure improve up to 18.9% and 40.9 lm/W, respectively. Moreover, this mixed-host structure device shows over 30% enhanced performance compared with a single-host structure device at a luminance of 10,000 $cd/m^2$ without any change in the electroluminescence spectra.

• Journal of the Korean housing association
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• v.18 no.1
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• pp.141-148
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• 2007

In this research, to develope wooden house model with post & beam structure which is commensurate with domestic environment, we analyzed the size and module of a unit space and space organization of existing habitation, then, based on the result, we tried to suggest general wood house modules. For this, we investigated 98 floor plans for 30 pyeong apartment in Seoul, Gyounggi-do, Gwangju, and Jeolla-do. The results are showed as follows. 1) It has shown that 7 posts distances are available in 2 bay floor plan type - 3.0 m, 3.3 m, 3.6 m, 3.9 m, 4.2 m, 4.5 m, and 4.8 m. 2) It has shown that 8 posts distances are available in 3 bay floor plan type - 3.0 m, 3.3 m, 3.6 m, 3.9 m, 4.2 m, 4.5 m, 4.8 m, and 5.1 m. It was concluded as follows, applying the standard of regulations of horizontal modular coordination design, from $\ulcorner$the standard of modular coordination design in architecture(KSF 1525)$\lrcorner$. 1) The available widths are 3.0 m, 3.3 m, 3.6 m, 4.2 m, and 4.8 m, and the available depths are 3.0 m, 3.3 m, 3.6 m, and 4.2 m. 2) To guarantee a space through post module of a room combination, we can use a module of 3.6 m, 4.2 m, 4.8 m except 3.0 m, 3.3 m among available modules. The module investigated in post & beam structure wooden house is applied in basic 6 floor plans as follows. 1) When organize the room on the basis of tile module of 3.6 m, 4.2 m, it was possible to organize the floor plan. 2) After arranging main room, making practical application of variableness which is advantage of post & beam structure, putting to practical use of extra space that becomes the combination of atypical room such as kitchen, dining room, and bathroom, it was possible to organize the floor plan of the residence. 3) It is possible to organize whole rooms through the plan module from 3.6 m to 4.2 m, that decides the floor plan of a wooden house.

• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2541-2543
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• 1998

This paper describes the fabrication process to fabricate metallic structure of high aspect ratio using LlGA-like process. SU-8 is used as an electroplating mold. SU-8 is an epoxy-based photoresist, designed for ultrathick PR structure with single layer coating [1,2]. We can get more than $100{\mu}m$ thick layer by single coating with conventional spin coater, and applying multiple coating can make thicker layers. In the experiments, we used different kinds of SU-8, having different viscosity. To optimize the conditions for mold fabrication process, experiments are performed varying spinning time and speed, soft-bake, develop and PEB (Post Expose Bake) condition. With the optimized condition, minimum line and space of $3{\mu}m$ pattern with a thickness of $40{\mu}m$ and $4{\mu}m$ pattern with a thickness of $130{\mu}m$ were obtained. Using the patterned PR as a plating mold, metallic structure was fabricated by electroplating. We have fabricated a electroplated nickel comb actuator using SU-8 as plating mold. The thickness of PR mold is $45{\mu}m$ and that of plated nickel is$40{\mu}m$. Minimum line of the mold is $5{\mu}m$. Patterned metallic layer or polymer layer, which has selectivity with the structural plated metallic layer, can be used as sacrificial layer for fabrication of free-standing structure.