• Communications of the Korean Mathematical Society
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• v.28 no.3
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• pp.589-596
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• 2013

This paper is an attempt to study and introduce the notion of ${\omega}$-dense set in weak structures and the notion of m-dense set in minimal structures. We have also investigate the relationships between ${\omega}$-dense sets, $m$-dense sets, ${\sigma}({\omega})$ sets, ${\pi}({\omega})$ sets, $r({\omega})$ sets, ${\beta}({\omega})$ sets, m-semiopen sets and $m$-preopen sets. Further we give some representations of the above generalized sets in minimal structures as well as in weak structures.

• The Pure and Applied Mathematics
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• v.6 no.1
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• pp.13-16
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• 1999

We introduce the notion of the $\omega$-derived set and $\omega$-dense, and investigate some of their properties.

• Journal of the Korean Mathematical Society
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• v.51 no.4
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• pp.837-851
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• 2014

We consider ${\omega}$-chaos as defined by S. H. Li in 1993. We show that c-dense ${\omega}$-scrambled sets are present in every transitive system with two-sided limit shadowing property (TSLmSP) and that every transitive map on topological graph has a dense Mycielski ${\omega}$-scrambled set. As a preliminary step, we provide a characterization of dynamical properties of maps with TSLmSP.

• Journal of the Korean Ceramic Society
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• v.22 no.6
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• pp.87-93
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• 1985

The hematite the magetite and the maghemite thin film were prepared by oxidation and reductino of the vaccum-evaporated iron thin film. Interre;atoms between film preparation process and the electrical properties were investigated. At room temperature the electrical conductivity of the iron the hematite the magnetite and the maghemite thin film were $1{\times}10^4\Omega^{-1}cm^{-1}$, 2{\times}10^{-5}\Omega^{-1}cm^{-1}$, $3{\times}10^{-5}\Omega^{-1}cm^{-1}$, and $4{\times}10^{-5}\Omega^{-1}cm^{-1}$, resp-ectively. The surface of each thin film was dense and homogeneous. At the temperature that the iron thin film was converted into the hematite thin film the electrical conductivity decreased rapidly and the electrical con-ductivity of the hematite thin film increased as temperature increased. The hematite thin film was reduced to the magnetite thin film in H2 atmosphere. The electrical conductivity decreased rapidly at the temperature that the maghemite thin film is formed by oxidation of the magnetite thin film and the electrical conductivity of the maghemite thin film increased as temperature increased.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.405-414
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• 1999

The auger and screw piles have known an important evolution during the last decade. Besides the large success of augercast (CFA) piling systems, new systems have been developed combining, to a variable extent, the classical extraction auger with especially designed displacement tools in order to develop screw piles with partial or total lateral soil displacement. These last developments cover the whole range of lateral soil displacement and are more difficult than ever to compare. The authors present the latest evolutions in auger piling systems and compare them with respect to penetration performances, bearing capacities and amount of spoil generated. A special focus is given to a new efficient system: the OMEGA(H) pile in use in Korea since 1997. The results of the Hongcheon site are presented where this R system was applied for a new investment of the Korean National Housing Corporation (KNHC). This first important experience, with the execution of some 1,500 Omega piles with diameter 410 mm, is presented. The piles were installed through loose silty sands down to very dense sands and layers of gravel. The results of full-scale load tests are analysed and show the conformity with requirements of the clients.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.8
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• pp.645-649
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• 2009

We investigated the effects of a high density $O_2$ plasma treatment on the structural and electrical properties of Ga-, B- codoped ZnO (GZOB) films. The GZOB films were deposited on polymer substrate without substrate heating by DC magnetron sputtering. Prior to the GZOB film growth, we treated a polymer substrate with highly dense inductively coupled oxygen plasma. The optical transmittance of the GZOB film, about 80 %, was maintained regardless of the plasma pre-treatment. The resistivity of the GZOB film on PC substrate decreased from 9.08 ${\times}$ $10^{-3}$ ${\Omega}-cm$ without an $O_2$ plasma pre-treatment to 2.12 ${\times}$ $10^{-3}$ ${\Omega}-cm$ with an $O_2$ plasma pre-treatment. And PES substrate decreased from 1.14 ${\times}$ $10^{-2}$ ${\Omega}-cm$ without an $O_2$ plasma pre-treatment to 6.13 ${\times}$ $10^{-3}$ ${\Omega}-cm$ with an $O_2$ plasma pre-treatment.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.3
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• pp.149-154
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• 2000

Bi-layer Mo films were deposited on soda-lime glass substrates using DC magnetron supttering. Increasing gas pressure, the resistivity varied from $1\times10^{-5}\; to\; 8.3\times10^{-3}\; \Omega.cm$. Furthermore, stress direction yielded compressive-to-tensile transition stress curves. The micro-structure of the compressively-stressed film which had poor adhesion consists of tightly packed columns, but of the tensile-stressed films had less dense structure. Under all gas pressure conditions, Mo films exhibited distinctly increasing optical reflection with decreasing gas pressure. The expansion of (110) peak width with the gas pressure meant the worse crystalline growth. The impurity levels in the Mo film exhibited highly concentrated Na, Se and O elements due to less dense micro-structure. The degree of Na diffusion depends on the type of the glass substrate used and the nature of the Mo film.

• Bulletin of the Korean Mathematical Society
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• v.38 no.4
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• pp.741-751
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• 2001

In this paper when $(M, \omega)$ is a compact weakly exact symplectic manifold with nonempty boundary satisfying $c_1｜{\pi}_2(M)$ = 0, we construct an action spectrum bundle over the group of Hamil-tonian diffeomorphisms of the manifold M generated by the time-dependent Hamiltonian vector fields, whose fibre is nowhere dense and invariant under symplectic conjugation.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.3 s.36
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• pp.253-258
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• 2005

Characteristics of electroplated Ni films such as grain size, resistivity, solder wetting angle, and growth rate of intermetallic compound were evaluated as a function of electroplating current density. With increasing the electroplating current density from $5\;mA/cm^2 $ to $40\;mA/cm^2 $, the nodule size on the Ni film surface decreased, grain refinement occurred, and resistivity increased from $7.37\mu\Omega-cm$ to $9.13\mu\Omega-cm$. Compared with Ni film processed at $40\;mA/cm^2 $, Ni films electroplated at $5\;mA/cm^2 $ and $10\;mA/cm^2 $ exhibited low resistivity, dense microstructure, and slow growth rate of intermetallic compound. Ni films electroplated at $5\;mA/cm^2 $ and $10\;mA/cm^2 $ are more suitable for Ni UBM application than that fabricated at $40\;mA/cm^2 $.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.150-152
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• 2003

YBa$_2$Cu$_3$O$_{7-{\delta}}$(YBCO) coated conductors were deposited by pulsed laser deposition (PLD) on short buffered substrate in continuous PLD reel-to-reel system. The oxide multilayer buffered substrate of architectures of CeO$_2$/YSZ/Y$_2$O$_3$was fabricated by PLD at steady status. The degree of texture of each layer was investigated using X-ray diffraction including $\theta$-2$\theta$ scans, $\omega$-scans and $\Phi$-scans analysis. Their surface morphology was observed by scanning electron microscopy (SEM) The FWHM of the X-ray $\omega$-scans and $\Phi$-scans indicated that YBCO and buffer layers closely replicate the in-plane and out-of-plane texture of metal tape. Critical current at 77K self-field of 19A, critical temperature of 86K, and current density of 2MA/$\textrm{cm}^2$ were measured. The film also exhibits a homogeneous and dense surface morphology.e morphology.