• 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.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.247-253
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• 2021

Electrocoalescence is an active technique in petroleum industry, formation of raindrop in cloud, and digital microfluidics. In the present work, electrocoalescence of two droplets under the constant electric potential in air was studied. Through this experiment, we found that the electrocoalescence process could be divided three phases; deformation, formation of liquid bridge, and merging. And the condition for formation of liquid bridge between two droplets was obtained. For the connection of experimental result in constant potential condition with general case in constant charge condition, relationship of charge and potential difference was deduced by numerical computation. In high electric potential case, flat interfaces after recoiling were observed. It was interpreted through a numerical simulation of electric field.

• The Pure and Applied Mathematics
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• v.28 no.2
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• pp.155-185
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• 2021

Orders and types of entire functions have been actively investigated by many authors. In this paper, we investigate some basic properties in connection with sum and product of generalized relative order (𝛼, 𝛽), generalized relative type (𝛼, 𝛽) and generalized relative weak type (𝛼, 𝛽) of entire functions with respect to another entire function where 𝛼, 𝛽 are continuous non-negative functions on (-∞, +∞).

• Journal of Advanced Information Technology and Convergence
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• v.10 no.2
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• pp.103-110
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• 2020

The course evaluations was used to collect the students' opinion and verify the learning performance for a long time. However, many evaluations' methods are not consider each characteristics of the course, and many courses were presented to students with the same question for the course evaluations. This research aims to make a learning success model considering the questionnaire of course evaluations and relationship between the factors of learning and learning satisfaction/benefit. In order to make a model, we identify the items of the questionnaire and distinguish the factors considering the items. The factors are Information Quality, Knowledge Quality, System Quality and Service Quality. Consequently, the research shows the connection and relationship between them and learning satisfaction/benefit.

• Asia Marketing Journal
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• v.24 no.3
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• pp.131-140
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• 2022

The current study examines how ethnocentrism influences the relationship between country image, product image, quality, and purchase intention for foreign goods. It is necessary to explore and analyze the connection between consumer ethnocentrism and purchase intention to develop marketing strategies that influence consumers' purchasing decisions. Accordingly, this article develops the research model to determine the impact of specific product determinants on consumer purchase intention towards foreign products. An online survey was carried out to reach the research objective. Four hundred effective questionnaires were analyzed using SPSS 23 and Smart PLS 3.3. The results showed that foreign product quality and image have a significant positive impact on consumers' intentions to buy foreign goods. Furthermore, consumer ethnocentrism significantly moderates product quality and purchase intention relationships. The study's findings could help marketers develop effective marketing techniques while also being helpful to academics and consumers in general.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.193-194
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• 2022

The use of high-strength grout for facility foundations and bridges has recently been expanding in offshore wind farms. Offshore wind farms require a bearing capacity for horizontal loads such as wind, waves. Therefore, in this study, the strength of the high-strength grout discharged through pump pressure was measured and compared with the existing strength to secure the strength after the underwater pump pressure of the high-strength grout used in the offshore wind connection. The compressive strength measurement showed that the strength difference at each position of the core specimen was 1% higher than that of the other specimens, and there was almost no change in the strength according to the height. The strength of the core specimen decreased by 23% compared to the existing strength, which is similar to the result of this study because the strength of the core specimen decreased by approximately 25% compared to the general specimen according to related research. Therefore, it is believed that there is no decrease in strength due to underwater pumping.

• Bulletin of the Korean Mathematical Society
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• v.61 no.2
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• pp.433-450
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• 2024

Using a Reilly type integral formula due to Li and Xia [23], we prove several geometric inequalities for affine connections on Riemannian manifolds. We obtain some general De Lellis-Topping type inequalities associated with affine connections. These not only permit to derive quickly many well-known De Lellis-Topping type inequalities, but also supply a new De Lellis-Topping type inequality when the 1-Bakry-Emery Ricci curvature is bounded from below by a negative function. On the other hand, we also achieve some Lichnerowicz type estimate for the first (nonzero) eigenvalue of the affine Laplacian with the Robin boundary condition on Riemannian manifolds.

• Dementia and Neurocognitive Disorders
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• v.21 no.3
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• pp.83-92
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• 2022

Telomeres are located at the end of chromosomes. They are known to protect chromosomes and prevent cellular senescence. Telomere length shortening has been considered an important marker of aging. Many studies have reported this concept in connection with neurodegenerative disorders. Considering the role of telomeres, it seems that longer telomeres are beneficial while shorter telomeres are detrimental in preventing neurodegenerative disorders. However, several studies have shown that people with longer telomeres might also be vulnerable to neurodegenerative disorders. Before these conflicting results can be explained through large-scale longitudinal clinical studies on the role of telomere length in neurodegenerative disorders, it would be beneficial to simultaneously review these opposing results. Understanding these conflicting results might help us plan future studies to reveal the role of telomere length in neurodegenerative disorders. In this review, these contradictory findings are thoroughly discussed, with the aim to better understand the role of telomere length in neurodegenerative disorders.

• Journal of KIISE:Information Networking
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• v.30 no.2
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• pp.207-221
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• 2003

A hash chain is highly efficient, attractive structure to use in electronic cash. Previous systems using hash chain were, however, either credit-based vendor-specific cash or debit-based general-purpose cash which lacks efficiency due to double spending problem. In this paper, we propose a new divisible cash system using hash chain. This newly proposed cash is general-purpose, debit-based, anonymous, and offline. The efficiency of the system results from its capacity to pay variable amounts with no additional costs. A client always performs a single blind signature in the withdrawal phase, independent of the length of the chain. During payment, a client performs a single challenge-and-response or generates a single signature, independent of the amount paid. This system provides a new refund mechanism, which uses a refund ticket, that allows clients to refund the unspent part of the chain without revealing any connection to the spent part.

• Journal of Digital Convergence
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• v.16 no.3
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• pp.385-394
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• 2018

The purpose of this study was to examine the effects of hospital organizational culture, organizational silence and job complexity on turnover intention in nurses working in general hospitals. The subjects were 152 nurses working at general hospitals. Data were collected from April 19, 2017 to April 30, 2017, and statistical analysis was analyzed by hierarchical multiple regression analysis using the SPSS/WIN 22.0 program. As a result of the research, turnover intention showed a positive correlation with resignation and defensive silence, whereas there was negative correlation between consensual organizational culture, sacrifice, suitability and connection of job inclination. The factors affecting the turnover intention were the present work experience, defensive silence, sacrifice, and the explanatory power of turnover intention was 47%. Therefore, in order to lower the turnover intention, it will be necessary to provide various programs to change the communication pattern in the nursing organization, and to provide differentiated welfare system.