• Progress in Superconductivity
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• v.1 no.2
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• pp.85-88
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• 2000

The temperature dependent Josephson critical current $J_c(T)/J_c(0)$ between high $T_c$ superconductors along the a-axis is theoretically studied. The interface influence on the wave functions of quasi-particles is included in the theory within the framework of the two-dimensional t-J model. It is found that the experimental results can be satisfactorily explained by the present model with d wave pairing symmetry.

• Communications of the Korean Mathematical Society
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• v.39 no.1
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• pp.149-160
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• 2024

In this paper, we give sufficient conditions for the generalized Ornstein-Uhlenbeck operators perturbed by regular potentials and inverse square potentials A_Φ,G,V,c=∆-∇Φ·∇+G·∇-V+c|x|^-2 with a suitable domain generates a quasi-contractive, positive and analytic C₀-semigroup in L^p(ℝ^N , e^-Φ(x)dx), 1 < p < ∞. The proofs are based on an L^p-weighted Hardy inequality and perturbation techniques. The results extend and improve the generation theorems established by Metoui [7] and Metoui-Mourou [8].

• Computers and Concrete
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• v.2 no.6
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• pp.455-479
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• 2005

This paper describes a 2D nonlinear finite element analysis (NLFEA) platform that combines heat flow analysis with realistic analysis of cracked reinforced concrete structures. The behavior models included in the structural analysis are mainly based on the Modified Compression Field Theory and the Distributed Stress Field Model. The heat flow analysis takes into account time-varying thermal loads and temperature-dependent material properties. The capability of 2D nonlinear transient thermal analysis is then implemented into a nonlinear finite element analysis program VecTor2(C) for 2D reinforced concrete membranes. Analyses of four numerical examples are performed using VecTor2, and results obtained indicate that the suggested nonlinear finite element analysis procedure is capable of modeling the complete response of a concrete structure to thermal and mechanical loads.

• Bulletin of the Korean Chemical Society
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• v.11 no.4
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• pp.303-306
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• 1990

Kinetic studies were carried out for the redox reaction of $[Co(NH_3)_4(C_2O_4)]^+$ with aqueous $[Fe(H_2O)_6]^{2+}$ solution in the present of $H^+$ by UV/VIS-spectrophotometric method. It was found that the order of $H^+$ for the reaction is first one in the higher $H^+$ concentration range of $1.67×10^{-1} M{\sim}1.00 M,$ while second order in the lower range of $6.30×10^{-2} M{\sim}1.67{\times}10^{-1} M.$ Reaction order of the substrates was found to be first order with respect to each of them. Accordingly overall reactions are third or fourth order. The results of calculation for the Extended Huckel Molecular Orbital theory contribute to estimate the preferred intermediates, bridging form of binuclear complex. On the basis of these results, we propose that this redox reaction proceed via inner-sphere reaction mechanism.

• The Pure and Applied Mathematics
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• v.2 no.2
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• pp.149-156
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• 1995

In stability theory of polysystems two concepts that playa very important role are the limit set and the prolongational limit set. For the above two concepts, A.Bacciotti and N.Kalouptsidis studied their properties in a locally compact metric space [2]. In this paper we investigate their results in c-first countable space which is more a general space than a metric space.(omitted)

• Bulletin of the Korean Mathematical Society
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• v.27 no.2
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• pp.189-196
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• 1990

In this paper, we try to generalize ultraproducts in the category of locally convex spaces. To do so, we introduce D-ultracolimits. It is known [7] that the topology on a non-trivial ultraproduct in the category T $V^{ec}$ of topological vector spaces and continuous linear maps is trivial. To generalize the category Ba $n_{1}$ of Banach spaces and linear contractions, we introduce the category L $C_{1}$ of vector spaces endowed with families of semi-norms closed underfinite joints and linear contractions (see Definition 1.1) and its subcategory, L $C_{2}$ determined by Hausdorff objects of L $C_{1}$. It is shown that L $C_{1}$ contains the category LC of locally convex spaces and continuous linear maps as a coreflective subcategory and that L $C_{2}$ contains the category Nor $m_{1}$ of normed linear spaces and linear contractions as a coreflective subcategory. Thus L $C_{1}$ is a suitable category for the study of locally convex spaces. In L $C_{2}$, we introduce $l_{\infty}$(I. $E_{i}$ ) for a family ( $E_{i}$ )$_{i.mem.I}$ of objects in L $C_{2}$ and then for an ultrafilter u on I. we have a closed subspace $N_{u}$ . Using this, we construct ultraproducts in L $C_{2}$. Using the relationship between Nor $m_{1}$ and L $C_{2}$ and that between Nor $m_{1}$ and Ba $n_{1}$, we show thatour ultraproducts in Nor $m_{1}$ and Ba $n_{1}$ are exactly those in the literatures. For the terminology, we refer to [6] for the category theory and to [8] for ultraproducts in Ba $n_{1}$..

• Korean Journal of Child Education & Care
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• v.18 no.2
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• pp.17-32
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• 2018

The purpose of this study is to examine the development of theory of mind on the story sharing with picture books. The subject of this study is 38 five years olds children who are attending C kindergarten in J city, Jeollabuk-do province. It was executed that an twelve sections of storytelling with picture books during six weeks. The storytelling activities were performed with predicting and listening of picture book contents, problem situation knowing and story sharing, feeling of the character mind condition, and activities evaluating. The results were as follows. First, the story sharing with picture books were significantly different between the groups on the development of mind. Second, the story sharing with picture books including theory of mind were effective on the perspective taking ability. The results showed that the story sharing with picture books was effective teaching and learning method.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.193-193
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• 2013

Perfluorocarbons (PFCs) have been suggested as possible replacements for $SF_6$ and the fluorocarbons used in and emitted during technological plasma treatments because PFCs have significantly low greenhouse warming potentials. Of many PFCs, c-$C_4F_8$ and 2-$C_4F_8$ attract special attention because of their high CF2 radicallevels in commercial plasma treatments. Accordingly, several experimental and theoretical studies of these $C_4F_8$ species have been conducted, although only the geometries at their stationary states and their adiabatic electron affinities (EAs) have been determined. However, this information is not sufficient for a deep understanding of all the possible fates and roles of $C_4F_8$ species and their fragments in plasma phases. Although the performance and reliability ofeach DFT functional have been examined carefully by the development team of each functional form with respect to the training and test data sets of well-known molecular systems, no PFC was included in the data sets. So a careful additional assessment of the reliability of DFT functionals for the study of PFC systems is highly required. In order to find a DFT method appropriate to PFCs, the geometry, energy, and chemical reaction properties of $C_4F_8$ were calculated and compared with reference data.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.136-136
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• 2013

High-resolution photoemission spectroscopy (HRPES) measurements were collected and density functional theory (DFT) calculations were conducted to track the coverage dependent variation of the absorption structure of 2-thiophenecarboxaldehyde (C4H3SCHO: TPCA) on the Ge(100) surface at room temperature. In an effort to identify the most probably adsorption structures on the Ge(100) surface, we deposited TPCA molecules at a low coverage and at a high coverage and compared the differences between the electronic features measured using HRPES. The HRPES data provided three possible adsorption structures of TPCA on the Ge(100) surfaces, and DFT calculations were used to determine the plausibility of the structures. HRPES analysis, corroborated by DFT calculations, indicated that an S-dative bonded structure was the most probable adsorption structure at relatively lower coverage levels, the [4+2] cycloaddition structure was the second most probable structure, and the [2+2]-C=O cycloaddition structure was the last probable structure on the Ge(100) surfaces at relatively higher coverage levels.

• Journal of Korea Foundry Society
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• v.7 no.1
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• pp.45-52
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• 1987

The effects of melting and casting conditions on cast structures of Cu-Sn-Pb alloys were studied. Specimens were prepared at different pouring temperatures of $1100^{\circ}C$ to $1260^{\circ}C$ with use of various kind of molds, green sand mold, $CO_2$ sand mold, shell mold, furan sand mold and metallic mold. (1) The transition of equiaxed to columnar structure greatly influenced by adding elements and mold binders. (2) The change of equiaxed structure according to pouring temperatures were expressed by separation theory. Lower pouring temperature and rapid cooling rate increase hardness and it's further increase was shown in the region of columnar structure. (3) Proper controls of pouring temperature, cooling rate and mold binder were important factors to improve wear properties of Cu-Sn-Pb alloys castings.