• Communications of the Korean Mathematical Society
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• v.23 no.3
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• pp.447-452
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• 2008

We provide some examples around AP and WAP spaces which are connected with higher convergence properties-radiality, semiradiality and pseudoradiality. We also prove a theorem (Theorem 3.2) that (a) any pseudo-open continuous image of an AP-space is an AP-space and (b) any pseudo-open continuous image of an WAP-space is an WAP-space. This answers the question posed by V. V. Tkachuk and I. V. Yaschenko [10].

• Journal of Industrial Technology
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• v.5
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• pp.47-49
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• 1985

Semi-open을 기초로 하여 만들어진 S-closed 공간의 일반적인 성질을 살펴보고 S-closed 공간과 (maximum) filterbase와의 관계를 조사하였다. 이를 바탕으로 regular closed된 cover C, regular open set인 족(族) C, rc-accumulation, (maximum) filterbase에서의 관계(關係)를 살펴 보았다. Mapping theory에서 almost-open almost-continuous map f가 almost continuous되는 것을 보였다.

• East Asian mathematical journal
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• v.26 no.3
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• pp.337-350
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• 2010

Strong convergence theorem of the explicit viscosity iterative scheme involving the sunny nonexpansive retraction for nonexpansive nonself-mappings is established in a reflexive and strictly convex Banach spaces having a weakly sequentially continuous duality mapping. The main result improves the corresponding result of [19] to the more general class of mappings together with certain different control conditions.

• Communications of the Korean Mathematical Society
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• v.39 no.2
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• pp.399-406
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• 2024

We point out an error appeared in the paper of Yuan et al. [3] and present a correction of their result under a more general assumption. Moreover, we discuss the validity of the conditions imposed on the sequences of error terms.

• The Journal of Economics, Marketing and Management
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• v.11 no.5
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• pp.29-44
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• 2023

Purpose: This study analyzed the effect of the perceived value of the OTT platform on consumers' technology acceptance, continuous use intention, and WOM using the Expanded TAM. Research design, data and methodology: A survey was conducted targeting OTT platform users in their 20s to 40s nationwide from August 10 to 16, 2022, and a total of 208 people were used in the final analysis. To verify the research model, frequency analysis, CFA, and SEM analysis were performed using SPSS and AMOS. Results: First, the perceived value of the OTT platform was found to have a positive effect on consumers' technology acceptance (perceived usefulness, perceived ease of use, and perceived enjoyment). Second, the perceived ease of use of OTT platform consumers was found to have a positive effect on perceived usefulness and perceived enjoyment. Third, it was found that the perceived usefulness and perceived enjoyment of OTT platform consumers had a positive effect on the continuous use intention, and WOM. Fourth, it was found that the continuous use intention the OTT platform had a positive effect on the WOM. Conclusions: Word of mouth and continuous use of existing customers are important for OTT platform companies to retain existing customers and secure new customers. Through the perceived value of the OTT platform, efforts should be made to provide various contents that consumers can enjoy along with usefulness and convenience of functions.

• BMB Reports
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• v.55 no.10
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• pp.512-517
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• 2022

Traumatic brain injury (TBI) is brain damage which is caused by the impact of external mechanical forces. TBI can lead to the temporary or permanent impairment of physical and cognitive abilities, resulting in abnormal behavior. We recently observed that a single session of early exercise in animals with TBI improved their behavioral performance in the absence of other cognitive abnormalities. In the present study, we investigated the therapeutic effects of continuous exercise during the early stages of TBI in rats. We found that continuous low-intensity exercise in early-stage improves the locomotion recovery in the TBI of animal models; however, it does not significantly enhance short-term memory capabilities. Moreover, continuous early exercise not only reduces the protein expression of cerebral damage-related markers, such as Glial Fibrillary Acid Protein (GFAP), Neuron-Specific Enolase (NSE), S100β, Protein Gene Products 9.5 (PGP9.5), and Heat Shock Protein 70 (HSP70), but it also decreases the expression of apoptosis-related protein BAX and cleaved caspase 3. Furthermore, exercise training in animals with TBI decreases the microglia activation and the expression of inflammatory cytokines in the serum, such as CCL20, IL-13, IL-1α, and IL-1β. These findings thus demonstrate that early exercise therapy for TBI may be an effective strategy in improving physiological function, and that serum protein levels are useful biomarkers for the predicition of the effectiveness of early exercise therapy.

• Journal of Korea Foundry Society
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• v.33 no.4
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• pp.157-161
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• 2013

A ribbon-type polycrystalline silicon wafer was directly fabricated from liquid silicon via a novel technique for both a fast growth rate and large grain size by exploiting gas pressure. Effects of processing parameters such as moving speed of a dummy bar and the length of the solidification zone on continuous casting of the silicon wafer were investigated. Silicon melt extruded from the growth region in the case of a solidification zone with a length of 1cm due to incomplete solidification. In case of a solidification zone wieh a length of 2 cm, on the other hand, continuous casting of the wafer was impossible due to the volume expansion of silicon derived from the liquid-solid transformation in solidification zone. Consequently, the optimal length of the solidification zone was 1.5 cm for maintaining the position of the solid-liquid interface in the solidification zone. The silicon wafer could be continuously casted when the moving speed of the dummy bar was 6 cm/min, but liquid silicon extruded from the growth region without solidification when the moving speed of the dummy bar was ${\geq}$ 9 cm/min. This was due to a shift of the position of the solid-liquid interface from the solidification zone to the moving area. The present study reports experimental findings on a new direct growth system for obtaining silicon wafers with both high quality and productivity, as a candidate for an alternate route for the fabrication of ribbon-type silicon wafers.

• Bulletin of the Korean Mathematical Society
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• v.49 no.4
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• pp.829-850
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• 2012

In this paper, we adopt symmetric interior penalty discontinuous Galerkin (SIPG) methods to approximate the solution of nonlinear viscoelasticity-type equations. We construct finite element space which consists of piecewise continuous polynomials. We introduce an appropriate elliptic-type projection and prove its approximation properties. We construct semidiscrete discontinuous Galerkin approximations and prove the optimal convergence in $L^2$ normed space.

• Bulletin of the Korean Mathematical Society
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• v.46 no.5
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• pp.835-844
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• 2009

The ridgelet transform is extended to the space of square integrable Boehmians. It is proved that the extended ridgelet transform $\mathfrak{R}$ is consistent with the classical ridgelet transform R, linear, one-to-one, onto and both $\mathfrak{R}$, $\mathfrak{R}^{-1}$.1 are continuous with respect to $\delta$-convergence as well as $\Delta$-convergence.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.53-68
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• 1999

To improve the slow convergence property of the steepest ascent type algorithm for continuous D-optimal design problems. we develop a new algorithm. We apply the nonlinear system of equations as the necessary condition of optimality and develop the two-point algorithm that solves the problem of clustering. Because of the nature of the steepest coordinate ascent algorithm avoiding the problem of clustering itself helps the improvement of convergence speed. The numerical examples show the performances of the new method is better than those of various steepest ascent algorithms.