• 한국노년학
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• v.32 no.2
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• pp.513-524
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• 2012

The purpose of this study was to examine the mediating effect of self-regulation and self-efficacy on relations between volunteering and happiness & meaning of life in the middle aged and the elderly. A total of 588 participants were asked to complete a questionnaire of volunteering, happiness, meaning of life, self-regulation, and self-efficacy. The results indicated that those participants who scored high on volunteering were also high in terms of happiness, meaning of life, self-regulation, and self-efficacy. Further, self-regulation and self-efficacy exercised mediating effects on the positive relations between volunteering and happiness & meaning of life. Finally, these finding were discussed in relation to their implications for happiness and meaning of life in the middle aged and the elderly and also limitations of the present study were suggested for future research.

• Natural Product Sciences
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• v.24 no.1
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• pp.13-20
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• 2018

Estragole is a naturally occurring phenylpropanoid obtained from essential oils found in a broad diversity of plants. Although the phenylpropanoids show many biological activities, clear regulation of the inflammatory signaling pathways has not yet been determined. Here, we scrutinized the anti-inflammatory effect of estragole. The anti-inflammatory effect of estragole was determined through the inhibitory mechanisms of inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2), nuclear factor kappa B ($NF-{\kappa}B$), and mitogen-activated protein kinases (MAPK) pathways and the activation of nuclear factor erythroid 2-related factor 2 (Nrf-2)/heme oxygenase (HO)-1 pathways in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Estragole significantly inhibited NO production, iNOS and COX-2 expression as well as LPS-induced $NF-{\kappa}B$ and MAPK activation. Furthermore, estragole suppressed LPS-induced intracellular ROS production but up-regulated the stress response gene HO-1 via the activation of transcription factor Nrf-2. These findings demonstrate that estragole inhibits the LPS-induced expression of inflammatory mediators via the down-regulation of iNOS, COX-2, $NF-{\kappa}B$, and MAPK pathways, as well as the up-regulation of the Nrf-2/HO-1 pathway, indicating that this phenylpropanoid has potential therapeutic and preventive applications in various inflammatory diseases.

• Molecules and Cells
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• v.26 no.3
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• pp.285-290
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• 2008

Estrogen-induced proliferation in estrogen receptor (ER)-positive breast cancer cells is primarily mediated through two distinct intracellular receptors, $ER{\alpha}$ and $ER{\beta}$. Although tumor necrosis factor alpha ($TNF{\alpha}$) and $E2/ER{\alpha}$ are known to exert opposing effects on cell proliferation in MCF-7 cells, the mechanism by which $TNF{\alpha}$ antagonizes $E2/ER{\alpha}$-mediated cell proliferation is not well understood. The present study suggests that reduced cell survival in response to $TNF{\alpha}$ treatment in MCF-7 cells may be associated with the down-regulation of $ER{\alpha}$ protein. The decrease in $ER{\alpha}$ protein level was accompanied by an inhibition of $ER{\alpha}$ gene transcription. Cell viability was decreased synergistically by the combined treatment with $ER{\alpha}$-siRNA and $TNF{\alpha}$. Furthermore, pretreatment of cells with the PI3-kinase (PI3K)/ Akt inhibitor, LY294002, markedly enhanced $TNF{\alpha}$-induced down-regulation of the $ER{\alpha}$ protein, suggesting that the PI3K/Akt pathway might be involved in control of the $ER{\alpha}$ level. Moreover, down-regulation of $ER{\alpha}$ by $TNF{\alpha}$ was not inhibited in cells that were pretreated with the proteasome inhibitors, MG132 and MG152, which suggests that proteasome-dependent proteolysis does not significantly influence $TNF{\alpha}$-induced down-regulation of $ER{\alpha}$ protein. In contrast, the effect of the PI3K/Akt inhibitor on $ER{\alpha}$ was blocked in cells that were treated with LY294002 in the presence of the proteasome inhibitors. Collectively, our findings show that the $TNF{\alpha}$ may partly regulate the growth of MCF-7 breast cancer cells through the down-regulation of $ER{\alpha}$ expression, which is primarily mediated by a PI3K/Akt signaling.

• Journal of Information Technology Services
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• v.14 no.1
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• pp.115-128
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• 2015

As the life expectancy of human beings gets longer and our society changes into highly competitive arena, the implementation of online adult learning is growing, and therefore the learners in self-regulated scaffolding learning environments is becoming an important topic. This study is to investigate the main effects of scaffolding and self-regulation and the interaction effect on discussion participation and comprehension in online learning environments. To do this, ninety-nine adults taking online learning courses with the open university in Korea were investigated. Adult learners were divided into one of the four groups (no scaffolding, conceptual, strategic, and conceptual and strategic scaffoldings). Regarding self-regulation, learners were divided into two groups (low and high self-regulated) based on the mean score of subjective report of self-regulated learning. The results are as follows : First, 'strategic scaffolding' is more effective than 'conceptual scaffolding' in discussion participation (F=2.772, p < .05) and comprehension test (F=7.156, p < .05). Second, high self-regulated learners more actively participate than low self-regulated learners in discussion (F=6.230, p < .05), and achieve higher scores (F=4.863, p < .05). Third, there is no interaction effect between scaffolding strategies and the level of self-regulation. The theoretical and practical implications of these findings are discussed.

• Journal of Digital Convergence
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• v.14 no.12
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• pp.599-605
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• 2016

This paper was to explore the effect of spouse support and cognitive strategy for emotional regulation on retirement anxiety of middle aged men. The survey was carried out with middle aged employed men worked in 5 major cities. 313 copies of questionnaires were used in the survey except the ones insufficient respond. The data was analyzed by descriptive statistics, t-test, ANOVA, pearson correlation and Multiple Regression. As a result, Main results of this study could be presented as follows. Spouse support was the significant predictor to explain retirement anxiety of middle aged men, but cognitive strategy for emotional regulation didn't have the effectiveness to retirement anxiety of middle aged men. In conclusion, to alleviate retirement anxiety of middle aged men, in conjugal relations spouse support need to be strengthened.

• Journal of IKEEE
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• v.13 no.1
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• pp.11-18
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• 2009

In this paper, the stability of second order uncertain systems with regulation of PID type controllers is analyzed by using Lyapunov second method for the first time in the time domain. The property of the stability of PID regulation servo systems is revealed in sense of Lyapunov, i.e., bounded stability due to the disturbances and uncertainties. By means of the results of this stability analysis, the maximum norm bound of the error from the output without variation of the uncertainties and disturbances is determined as a function of the gains of the PID control, which make it enable to analyze the effect resulted from the variations of the disturbances and uncertainties using this norm bound for given PID gains. Using the relationship of the error from the output without variation of the uncertainties and disturbances and the PID gain with maximum bounds of the disturbances and uncertainties, the robust gain design rule is suggested so that the error from the output without the variation of the disturbances and uncertainties can be guaranteed by the prescribed specifications as the advantages of this study. The usefulness of the proposed algorithm is verified through an illustrative example.

• Environmental and Resource Economics Review
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• v.11 no.3
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• pp.345-375
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• 2002

The purpose of this paper is to measure the change of the production efficiency which may happen when environmental regulation incurs technological constraint in the process of production, and to compute the opportunity cost of pollution reduction with the lost products based on the change of efficiency. The patterns of production technoloy in the paper are divided into the technologies of strong disposability and weak disposabilty to grasp the effect of the technological constraint due to the environmental regulation. The endowment of the technolgical constraints in the process of production is considered to bring the greatest restriction on firm's production. When the environmental efficiencies of Korean regional manufactures were measured with linear programming model, the lost products related with the constraint of production technology that environmental regulation incurred, was average 148.1 billion dollar per year(5.87% of one year overall products) for total manufactures in 1991~1998. The ratio of the lost products for total products was spread from 0.78% to 1l.08%. The average lost products of 15 regions were changed from 4.66% to 18.35% of total products. Generally the environmental efficiency index of regional manufactures being decreased continuously since 1991, it is estimated that the environmental performance of Korean manufactures has been more and more deteriorating.

• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.77-82
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• 2012

The leakage of toxic chemicals impact seriously on human being and environment, therefore during their treatment process, a proper management system is necessary to control their toxic effect. This study was designed to suggest the management regulation that supports business managers and facilities management. There are no extra regulation to control emergency accidents and terrors in chemical facilities. Developed countries like USA operate the management standards to control the toxic chemical and facilities according to their toxicity and processes. In order to solve this problem, we have analysed the advanced nations standard methods of security in chemical plants to study the new security management regulation which helps to prevent the chemical accidents. Especially, in USA, CCPS (Center for Chemical Process Safety), SVA (Security Vulnerability Assessment) and RBPSs (Risk-Based Performance Standards) of DHS (Department of Homeland Security) were invest I gated. On the basis of the results, we have suggested the application methods of the security and safety regulation in Korea.

• Journal of Venture Innovation
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• v.5 no.2
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• pp.101-110
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• 2022

It is easy for first movers of platform business model to monopolize the market due to the platform's own characteristics such as network effect and flywheel strategy. Accordingly, the regulations on platform operators are constantly being discussed in the recent monopoly regulation arguments, but the concrete regulations have not been settled worldwide. This is because there is no clear consensus on the valuation method which can objectively identify dominant platform firms from the others. This study suggested a platform valuation method based on the Tobin's Q theory, by measuring the moderating effect of the existence of specific scale of platform on the relationship between replacement cost and market valuation. Our method can not only be a standard for settling monopoly regulation by converging the regulation targets, but also contribute to active investment on the new platform firms by evaluating their potential growths quantitatively.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.1B
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• pp.34-46
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• 2009

The remarkable growth of Korean telecommunication market has based on the introduction of competition as well as mobile technology like CDMA. It was well Down that such a conspicuous growth has been towed by mobile service rather than fixed telephone service. In telecommunications service the number of subscribers to mobile was over 40 millions in 2006 and also, while the traffic amount of fixed telephone has been more decreased, that of mobile, which already outnumbers the fixed, has been constantly increased and will be much more in future. It will accelerate the substitution of access and call demand of fixed service by mobile. This change of technology and demand does affect directly the market performance of telecommunications. And regulation has also an effect on market structure, which finally affects on market performance. In this paper we suppose the fixed and mobile telecommunications services are in a same industry. After reviewing the relations among the demand, cost, charge structure and revenue structure in the one fixed and mobile telecommunications market using the framework of an industrial structure analysis, we discuss the current issues of telecommunications regulation and implications for the future regulation.