• Journal of the Chungcheong Mathematical Society
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• v.28 no.2
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• pp.287-305
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• 2015

Hyperbolicity is a core of dynamics. Shadowness and expansiveness for homeomorphisms have been studied by J. Om-bach([3], [4], [5]). We study the hyperbolicity (i.e., expansivity and the shadowing property) and the Anosov relation for a closed relation.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.424-427
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• 1995

This paper proposes an analysis of an inverter circuit which has an induction heating load. Two major kinds of the inverters are E-class quasi resonant and half-bridge type. The analyses of induction heating load property and operation property are introduced. A simulation program which implements those properties is also introduced. The results of the simulation program are verified through experimental results.

• The Pure and Applied Mathematics
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• v.23 no.2
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• pp.131-143
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• 2016

In this paper, we present some common fixed point theorems for two pairs of weakly compatible self-mappings on multiplicative metric spaces satisfying a generalized Meir-Keeler type contractive condition. The results obtained in this paper extend, improve and generalize some well known comparable results in literature.

• Bulletin of the Korean Mathematical Society
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• v.56 no.5
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• pp.1219-1233
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• 2019

Let $E{\rightarrow}M$ be an arbitrary vector bundle of rank k over a Riemannian manifold M equipped with a fiber metric and a compatible connection $D^E$. R. Albuquerque constructed a general class of (two-weights) spherically symmetric metrics on E. In this paper, we give a characterization of locally symmetric spherically symmetric metrics on E in the case when $D^E$ is flat. We study also the Einstein property on E proving, among other results, that if $k{\geq}2$ and the base manifold is Einstein with positive constant scalar curvature, then there is a 1-parameter family of Einstein spherically symmetric metrics on E, which are not Ricci-flat.

• KDI Journal of Economic Policy
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• v.46 no.1
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• pp.53-89
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• 2024

The effects of the betterment of enforced intellectual property rights (IPRs) provisions on services export diversification are investigated. The analysis used an unbalanced panel dataset of 76 developing countries over the period of 1970-2014. The empirical analysis is based on the feasible generalized least squares estimator. It suggests that the implementation of weaker IPR protection fosters services export diversification in less developed countries (i.e., those whose real per capita incomes are less than US$US$ 1458.60), including those with a low level of export product upgrading. Conversely, in relatively advanced developing countries (countries whose real per capita income exceeds US$ 3356.80), including those with high levels of export product upgrading, the implementation of stronger IPR laws induces greater services export diversification. Finally, the analysis revealed the existence of a non-linear relationship between IPR protection and services export diversification. The implementation of stronger intellectual property laws spurs services export diversification in countries with high degree of IPR protection, especially when IPR protection exceeds a certain level, recorded here as having a score of 1.197. In contrast, in countries with weaker IPR protection, in particular those with IPR protection levels that score less than 0.915, it is rather the implementation of weaker intellectual property laws that promotes services export diversification.

• Journal of the Korean Vacuum Society
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• v.18 no.1
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• pp.60-65
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• 2009

We performed a study on optical properties of $BaSm_2Ti_4O_{12}$ thin films by vacuum ultra violet spectroscopic ellipsometry in the $0.92{\sim}8.6\;eV$ energy range. For the analysis of the measured ellipsometric spectra, a 5-layer model was applied where optical property of the $BaSm_2Ti_4O_{12}$ layer was well represented by a Tauc-Lorentz dispersion function. Our analysis clearly showed new structure in high energy region at about 7.5 eV Consistent changes of refractive index & extinction coefficient of the $BaSm_2Ti_4O_{12}$ thin film by the growth and annealing temperatures were also confirmed.

• International Journal of Concrete Structures and Materials
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• v.18 no.1E
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• pp.23-28
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• 2006

In this study, the general theory of fractality is discussed to provide a fundamental understanding of fractal geometry applied to heterogeneous material surfaces like pavement surface and rock surface. It is well known that many physical phenomena and systems are chaotic, random and that the features of roughness are found at a wide spectrum of length scales from the length of the sample to the atomic scales. Studying the mechanics of these physical phenomena, it is absolutely necessary to characterize such multi scaled rough surfaces and to know the structural property of such surfaces at all length scales relevant to the phenomenon. This study emphasizes the role of fractal geometry to characterize the roughness of various surfaces. Pavement roughness and rock surface roughness were examined to correlate their roughness property to fractality.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.22-22
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• 2010

0.1~5.0 at% CuO doped ZnO specimens were fabricated by a commercial ceramic process and sintered at 900~$1200^{\circ}C$ for 3h in air. The relative densities were over 97% for all samples and average grain size increased with CuO doping. The defect trap levels i.e. ionization energies of defects were increased linearly with CuO contents as 0.2 eV to 0.7 eV by using admittance spectroscopy and dielectric functions. The apparent activation energies of grain boundaries were varied but in the range of 0.96~1.1 eV. Dielectric constant were increased with CuO contents and sintering temperatures.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.272-277
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• 2003

Two antennas system which is aligned in cross direction is tested and analyzed. The main scope is focused to get an appropriated distance between the two small antennas to get a better property. The theoretical expectation and the computer simulation are executed simultaneously. The target is the folded IF antenna system printed on PCB, but the ideal dipole-antenna arrangement is also tested to verify the possibility of our implementation. And it is finally proved by experiments.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.800-805
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• 2012

Licochalcone E was firstly isolated from licorice root in 2005, which belongs to the retrochalcone family. Studies on the biological activities of licochalcone E were in the initial stage. In the study, we demonstrated that licochalcone E has potent antimicrobial property against Staphylococcus aureus. Furthermore, via hemolysis, Western blot, and real-time RT-PCR assays, we have shown that subinhibitory concentrations of licochalcone E dose-dependently reduces the production of ${\alpha}$-toxin in both methicillin-sensitive S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA). The data suggest that licochalcone E may deserve further investigation as a potential therapeutic against S. aureus infections, or the structure of licochalcone E may be used as a basis for chemical synthesis of novel anti-S. aureus compounds.