• Ocean and Polar Research
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• v.32 no.1
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• pp.41-52
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• 2010

Daily samples were collected during summer in order to analyse changes in the mesozooplankton community and to identify the major environmental factors that may influence mesozooplankton abundance in Jangmok Bay. A single site in the bay was sampled 47 times from July to September 2003. Mesozooplankton community, hydrographic (watertemperature, salinity, dissolvedoxygen) and biological (chlorophyll-a, ciliates densities, Noctiluca scintillans densities) factors were determined. The mesozooplankton abundance varied remarkably from 954 to $14,816\;inds.\;m^{-3}$. The six taxa of Evadne tergestina, barnacle nauplii and cypris, Paracalanus parvus s.1., Acartia omorii, Penilia avirostris and Sagitta crassa dominated numerically, contributing 86% of total mesozooplankton abundance. Stepwise multiple linear regression analysis was applied to find correlation between environmental factors and fluctuation in the abundance of dominant species and mesozooplankton. A. omorii was significantly correlated with temperature and N. scintillans densities. E. tergestina was correlated with temperature, salinity, and ciliate densities, whereas P. avirostris was correlated with temperature and dissolved oxygen. Among the environmental factors, mesozooplankton abundance correlated most strongly with N. scintillans densities. Accordingly, N. scintillans may be a key player in controlling the fluctuation of mesozooplankton abundance as a strong competitor for same food resources.

• Journal of the Korean Society for information Management
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• v.26 no.3
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• pp.377-394
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• 2009

There are some limitations in the existing bibliometric methods to satisfy the various requests of the interest parties including researchers, managers, policy makers to identify 1) which research group or researcher is the key player, and the overall trends of the particular technological sub-fields, 2) which research groups, institutions or countries mainly use their research outputs, 3) what are the spin-offs from research outputs to some scientific and technological fields, 4) in which levels they are when comparing their quantitative and qualitative research outputs to those of other competitive institutions. It is essential to develop new informetric indicators and methodologies in order to satisfy stakeholder's various demands and to strengthen qualitative analysis in measuring research performance. This study suggested informetric indicators such as article quality index, citation impact index, international cooperation index, excellent article production index and methodologies including citation analysis, text mining.

• International Journal of Contents
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• v.9 no.1
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• pp.71-80
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• 2013

The golf industry has become the center of attention for recreational activities in the participant sport market; however, there has been little effort made to understand golf consumer and their consumption behavior using the concept of 'recreational specialization' which segments the golfers based on level of specialization in golf. The purpose of this study was to explore the differences in the relationships among perceived service quality, price of playing golf, overall customer satisfaction with the course, and a player's intention to revisit the same golf course based on the magnitude of recreation specialization in golf. Four public and two private golf courses from the southeastern state of the United States were randomly chosen from a list in a golf magazine. The 365 surveys among 417 participants were ultimately analyzed. Multiple group analysis was conducted in order to investigate differences in relationships among service quality, price, customer satisfaction, and revisit intentions between groups based on the level of recreation specialization. The key findings were 1) for more specialized golfers, satisfaction with price did not affect overall customer satisfaction or revisit intention, however, service quality significantly influenced both overall customer satisfaction and revisit intention, 2) for less specialized golfers, satisfaction with price significantly influenced overall customer satisfaction but did not affect revisit intention. Knowledge about which the determinants of satisfaction are different between more and less specialized golfers could provide a better understanding of how different marketing strategies should be implemented for different specialized levels of golfers.

• YAKHAK HOEJI
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• v.56 no.2
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• pp.80-85
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• 2012

Previously, we have reported that arachidonic acid (AA) appears to be involved in the induction of apoptosis in HepG2 human hepatoblastoma cells. In this study we investigated the possible role of the NADPH oxidase, a membranebound enzyme generating reactive oxygen species (ROS), in the mechanism of AA-induced apoptosis in HepG2 cells. Apoptotic cell death induced by AA was significantly suppressed by various inhibitors of the NADPH oxidase, diphenylene iodonium (DPI), apocynin (Apo) and neopterine (NP). In addition, these inhibitors of the NADPH oxidase completely blunted the AA-induced ROS elevation. Next, we investigated the implication of metabolic pathway of AA in these AA actions. Both apoptosis and ROS production induced by AA were not significantly altered by treatment with indomethacin (Indo) or nordihydroguaiaretic acid (NDGA), selective inhibitors of cyclooxygenase (COX) and lipoxygenase (LOX), respectively, suggesting that AA metabolites produced by COX or LOX may not have an essential role in the AA-induced apoptosis and ROS generation. Collectively, these results suggest that the NADPH oxidase may be a key player in the mechanism of AA-induced apoptosis in HepG2 cells. These results further suggest that NADPH oxidase may be a good target for the management of human hepatomas.

• Journal of The Korean Association For Science Education
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• v.8 no.1
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• pp.73-79
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• 1988

According to the previous studies, the science education departments in the college of education should develop better curricula to teach future secondary school teachers in a more professional way As one example of such curricula developments. one important topics of modem physics was integrated to teach the future high school physics teachers In the physics education departments. The title is "The Physics of Solar Constant Measurement The surrounding core physics for this measurements were pulled together with these important points in minds(1) clear goal of learning In the teachers college physics(2) Clear explanation of physics and visualization of important technologies for the high school students(3) these teachings should encourage for the students to use the knowledge and technologies learned through the class toward the industrial applications Korea will move toward one of the heavily industrialized countries in the world where the physics education can become key player to manufacture physics based products. Therefore developments of physics curricula which relates teachers college, high school, and industry will become more and more Important.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.4
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• pp.1192-1207
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• 2014

Dynamic spectrum sharing is a key technology to improve spectrum utilization in wireless networks. The elastic spectrum management provides a new opportunity for licensed primary users and unlicensed secondary users to efficiently utilize the scarce wireless resource. In this paper, we present a game-theoretic framework for dynamic spectrum allocation where the primary users rent the unutilized spectrum to the secondary users for a monetary profit. In reality, due to the ON-OFF behavior of the primary user, the quantity of spectrum that can be opportunistically shared by the secondary users is limited. We model this situation with the renewal theory and formulate the spectrum pricing scheme with the Bertrand game, taking into account the scarcity of the spectrum. By the Nash-equilibrium pricing scheme, each player in the game continually converges to a strategy that maximizes its own profit. We also investigate the impact of several properties, including channel quality and spectrum substitutability. Based on the equilibrium analysis, we finally propose a decentralized algorithm that leads the primary users to the Nash-equilibrium, called DST. The stability of the proposed algorithm in terms of convergence to the Nash equilibrium is also studied.

• Culinary science and hospitality research
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• v.21 no.5
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• pp.50-58
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• 2015

The purpose of this study is to identify the causal relationships between service quality, consumer satisfaction, and behavioral intention in coffee shop. Additionally, the stud aims at focusing on whether or not consumer satisfaction plays a moderating role between service quality and behavioral intention. Statistical techniques that involve frequency, reliability, exploratory factor analysis, and structural equation modeling were performed. In the third research model, consumer satisfaction was unfolded as a moderating variable that enables to be a key player between service quality and behavioral intention. Limitations and considerations of this study were discussed for future study.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2540-2542
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• 2003

This paper presents an internet-based self-learning educational system which can be enhancing efficiency in the learning process of Java language. The proposed self-learning educational system is called Java Web Player(JWP), which is a Java application program and is executable through Java Web Start technologies. In this paper, three important sequential learning processes : concept learning process, programming practice process and assessment process are integrated in the proposed JWP using Java Web Start technologies. This JWP enables the learners to achieve efficient and interesting self-learning since the learning process is designed to enhance the multimedia capabilities on the basis of educational technologies. Also, online voice presentation and its related texts together with moving images are synchronized for efficient language learning process. Furthermore, a simple/useful compiler is included in the JWP for providing language practice environment such as coding, editing, executing and debugging Java source files. Finally repeated practice can make the learners to understand easily the key concepts of Java language. Simple multiple choices are given suddenly to the learners while they are studying through the JWP and the test results are displayed on the message box.

• Molecules and Cells
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• v.42 no.7
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• pp.523-529
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• 2019

mRNA quality is controlled by multiple RNA surveillance machineries to reduce errors during gene expression processes in eukaryotic cells. Nonsense-mediated mRNA decay (NMD) is a well-characterized mechanism that degrades error-containing transcripts during translation. The ATP-dependent RNA helicase up-frameshift 1 (UPF1) is a key player in NMD that is mostly prevalent in the cytoplasm. However, recent studies on UPF1-RNA interaction suggest more comprehensive roles of UPF1 on diverse forms of target transcripts. Here we used subcellular fractionation and immunofluorescence to understand such complex functions of UPF1. We demonstrated that UPF1 can be localized to the nucleus and predominantly associated with the chromatin. Moreover, we showed that UPF1 associates more strongly with the chromatin when the transcription elongation and translation inhibitors were used. These findings suggest a novel role of UPF1 in transcription elongation-coupled RNA machinery in the chromatin, as well as in translation-coupled NMD in the cytoplasm. Thus, we propose that cytoplasmic UPF1-centric RNA surveillance mechanism could be extended further up to the chromatin-associated UPF1 and co-transcriptional RNA surveillance. Our findings could provide the mechanistic insights on extensive regulatory roles of UPF1 for many cellular RNAs.

• Natural Product Sciences
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• v.28 no.3
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• pp.153-160
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• 2022

Neuroinflammation is known to be associated with brain injury in Alzheimer's disease (AD), and the inhibition of microglial activation, a key player in inflammatory response, is considerd as important target for AD. In this study, the ethanol extract of aerial parts of Forsythia velutina Nakai, a Korean native species, significantly inhibited nitric oxide (NO) production in LPS-stimulated BV2 microglial cells. Thus, the active principles in F. velutina aerial parts were isolated based on activity-guided isolation method. As a result, six compounds were isolated and their structures were elucidated based on NMR data and the comparison with the relevant references as arctigenin (1), matairesinol (2), rengyolone (3), ursolic acid (4), secoisolariciresinol (5), and arctiin (6). Among them, four compounds including arctigenin (1), matairesinol (2), secoisolariciresinol (5), and arctiin (6) significantly inhibited NO production in a dose-dependent manner. In particular, matairesinol (2) and secoisolariciresinol (5) reduced 60% of NO production compared to LPS-treated group. This inhibitory effects of matairesinol (2) and secoisolariciresinol (5) were accompanied with the reduced expression levels of iNOS and COX-2. These results suggest that the extract of F. velutina and its active compounds could be beneficial for neuroinflammatory diseases including AD.