• Journal of Korea Technology Innovation Society
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• v.10 no.3
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• pp.486-508
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• 2007

This study identifies key determinants of participation in UCC services. Incorporating insights from the flow theory, we examine the effects of psychological factors of social presence, self expression, arousal, and challenge as well as web-site characteristics variables of media easiness, contents usability, and immediateness. We have done a sample survey of internet users and collected 260 responses. Using Windows SPSS/PC 12.0 Package, we have performed statistical analyses including a correlation analysis, a factor analysis, and a multiple regression analysis. The result of the study is as follows. Psychological variables of perceived social presence, self expression, arousal, and challenge all show positive significant effect on participation in UCC service. Among web site characteristics, media easiness, which consists of a web structure that is easy-to-use, user friendliness, and personalized service, demonstrates a positive significant effect on participation in UCC services. Immediateness also has a positive significant effect. Some of the practical implications of the result are follows. We should improve user access to platforms of UCC service by opening up platforms. This will heighten perceived challenge which has the strongest influence on participation in UCC services. We need to focus on multimedia services and adjust to the cultural code of netizen who crave for visual expressions and on the spot on-line activities. Also suggested is that contributions made by participants need to be acknowledged through such provisions as profit sharing. Needs for individualized service, which is an aspect of media easiness, should also be addressed. Participants tend to value individuality while at the same time accepting broader trends. Information services need to be customized for individuals. In UCC centered internet businesses, netizen consumers are presumer. They are consumers and producers at the same time, and consumer needs should also be explored for the success of internet businesses.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1258-1266
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• 2005

The present study was carried out in order to assess the protective effects of calycosin-7-O-$\beta$-D-glucopyranoside, isolated from Astragali radix (AR), on hyaluronidase (HAase) and the recombinant human interleukin-$1\beta$ (IL-$1\beta$)-induced matrix degradation in human articular cartilage and chondrocytes. We isolated the active component from the n-butanol soluble fraction of AR (ARBu) as the HAase inhibitor and structurally identified as calycosin-7-O-$\beta$-D-glucopyranoside by LC-MS, IR, ${1}^H$ NMR, and ${13}^C$ NMR analyses. The $IC_{50}$ of this component on HAase was found to be 3.7 mg/ml by in vitro agarose plate assay. The protective effect of ARBu on the matrix gene expression of immortalized chondrocyte cell line C28/I2 treated with HAase was investigated using a reverse transcription polymerase chain reaction (RT-PCR), and its effect on HAase and IL-$1\beta$-induced matrix degradation in human articular cartilage was determined by a staining method and calculating the amount of degraded glycosaminoglycan (GAG) from the cultured media. Pretreatment with calycosin-7-O-$\beta$-D-glucopyranoside effectively protected human chondrocytes and articular cartilage from matrix degradation. Therefore, calycosin-7-O-$\beta$-D-glucopyranoside from AR appears to be a potential natural ant-inflammatory or antii-osteoarthritis agent and can be effectively used to protect from proteoglycan (PG) degradation.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.4
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• pp.85-104
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• 2003

Customer retention is more emphasized for internet business than off-line shopping-malls. The loyals not only purchase a lot but also recommend the mall to new customers quickly using internet media, and there have been many studies on this subject. In this study, customer satisfaction and trust are suggested as preceding variables that have an influence on customer loyalty, and switching gains are suggested as a moderating variable between customer satisfaction & trust and customer loyalty. Many people think it would be easier to change business connection and customer loyalty for internet shopping-malls would be very low. This study, however, concluded that customer satisfaction and trust had a significant influence on customer loyalty even in internet shopping-mall, and that switching gains had moderating effect between satisfaction-attitudinal loyalty and trust-behavioral loyalty. These results are meaningful in that customer satisfaction or trust should be emphasized even on internet business and that switching gains can be strategic focus in building up customer loyalty and retention.

• The Journal of Information Systems
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• v.23 no.3
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• pp.25-46
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• 2014

As the use of smartphone has rapidly spread into the current society, the mobile instant messenger applications such as Kakaotalk, Tiktok, and Line have become an indispensable part of our daily lives. While, the mobile instant messenger has brought us many positive changes, social problems stemming from the dependency on the mobile instant messenger has been occurred. The dependency of the mobile instant messenger can negatively affect daily lives and lead to stress or addiction. Therefore, it is very important to examine how we can prevent such dependency and addiction. In this respect, the purpose of this study is to investigate determinants impacting on the mobile instant messenger dependency, barrier of living, and intention to digital break. The statistical analysis of survey results shows that enjoyment, identity, relationship commitment, critical mass and ease of use are significantly related to mobile instant messenger dependency, while media richness is not significantly related. Mobile instant messenger dependency have a positive effect on barrier of living, which then has a positive effect on digital break. Lastly, the moderating effect of perceived risk is significant. This research suggests theoretical and business implications to prevent mobile instant messenger dependency.

• International Journal of Advanced Culture Technology
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• v.12 no.1
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• pp.254-261
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• 2024

Among eco-friendly energy, solar energy is one of the renewable energy sources that is developing in the spotlight in many countries. In line with this, the Korean government and local governments are carrying out projects to provide subsidies for the distribution of household solar power, raising the spread of household solar power and awareness. However, due to the lack of research on consumer perception of household solar power, this study investigated the perception of household solar power from 2015 to 2022 by setting the central word as solar power. As a result, 2016 had the highest number of collections, and when the top 50 words for each year were analyzed, it was confirmed that words related to the installation and maintenance of household solar power dominated. And through CONCOR analysis, a total of four were derived: solar energy recognition, renewable and eco-friendly energy recognition, solar government policies, solar companies, and perceptions of households. Through emotional analysis, it was confirmed that 2021 had the most positive data. As a result, consumer perception of household solar power is positive based on what was mentioned above, but research on how to use negative opinions on waste control and installation and maintenance should be conducted.

• Molecules and Cells
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• v.37 no.10
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• pp.734-741
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• 2014

Histone modifications on major transcription factor target genes are one of the major regulatory mechanisms controlling adipogenesis. Plant homeodomain finger 2 (PHF2) is a Jumonji domain-containing protein and is known to demethylate the histone H3K9, a repressive gene marker. To better understand the function of PHF2 in adipocyte differentiation, we constructed stable PHF2 knock-down cells by using the mouse pre-adipocyte cell line 3T3-L1. When induced with adipogenic media, PHF2 knock-down cells showed reduced lipid accumulation compared to control cells. Differential expression using a cDNA microarray revealed significant reduction of metabolic pathway genes in the PHF2 knock-down cell line after differentiation. The reduced expression of major transcription factors and adipokines was confirmed with reverse transcription- quantitative polymerase chain reaction and Western blotting. We further performed co-immunoprecipitation analysis of PHF2 with four major adipogenic transcription factors, and we found that CCATT/enhancer binding protein (C/EBP)${\alpha}$ and C/EBP${\delta}$ physically interact with PHF2. In addition, PHF2 binding to target gene promoters was confirmed with a chromatin immunoprecipitation experiment. Finally, histone H3K9 methylation markers on the PHF2-binding sequences were increased in PHF2 knock-down cells after differentiation. Together, these results demonstrate that PHF2 histone demethylase controls adipogenic gene expression during differentiation.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.12
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• pp.1741-1745
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• 2005

Zinc is a trace element that is associated with a stimulation of immune function and regulation of ion balance for livestock production. In this study, the effect of zinc as inhibitor to apoptosis-induced cells was examined in vitro using mammary epithelial cell line, HC11 and macrophage cell line, NCTC3749. Cell viability, measured by MTT assay, indicated that 10 g/ml of zinc had a negative impact on cellular activity and 50 ng/ml was chosen for further testing. Apoptosis was induced in cells treated with C2-ceramide in serum-free media. DNA fragmentation and gene expression of acidic sphingomyelinase (a gene responsible for the progress of apoptosis) were distinctively low in zinc treated cells compared with those in non-treated controls. In conclusion, zinc is involved in the regulation of cell proliferation and apoptosis in mammary epithelial cells and macrophages.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1121-1126
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• 2017

Recently, the importance of smart gateways that link these with the big data and the development of the Internet of things is getting bigger. The smart gateway includes a network function such as a router and a router, and a sensor network function that links various objects such as a sensor. As the internet market has expanded, network stability and security problems have arisen and VPN technology has been proposed as one of the ways to solve these security problems. Efficient design is needed to implement VPN in low-end smart gateway and SOHO-level Internet environment with poor line quality. In this paper, we propose the concept and principle of VPN tunneling implementation and real - time traffic shaping method according to internet line condition in the Smart Gateway that supports IOT developed based on OpenWRT, the implementation and measured performance indicators are presented.

• Korean Journal of Optics and Photonics
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• v.14 no.4
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• pp.429-433
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• 2003

We try to analyse the localization phenomenon of a lightwave in random media by means of considering the solution of the propagation equation on a transmission line in which the propagation constants are randomly distributed. Lightwave localization is generated at the turning point where the solution is changed suddenly from an increase to a decrease. First, in order to investigate the changing process of the solution, we have derived the approximated one-dimensional Schrodinger equation from the two-dimensional wave equation by using the Brags condition. Considering the many types of solutions of the wave equation, we have investigated the conditions that allow the solutions to exist. Also, we have investigated the relationships between the localization of the solution and the variation of the propagation constant. In case of the exponential solution, we know that the permittivity $\varepsilon$=(0,0$\varepsilon$$_{0}$) is a very important parameter to influence the phase of the lightwave and to generate the localization.

• Journal of Broadcast Engineering
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• v.14 no.2
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• pp.253-264
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• 2009

This paper presents an algorithm, aims at practical applications, for the high speed processing and performance enhancement of lane detection base on vision processing system. As a preprocessing for high speed lane detection, the vanishing line estimation and the optimal extraction of region of interest for lane boundary (ROI-LB) can be processed to reduction of detection region in which high speed processing is enabled. Image feature information is extracted only in the ROI-LB. Road lane is extracted using a non-parametric model fitting and Hough transform within the ROI-LB. With simultaneous processing of noise reduction and edge enhancement using the Laplacian filter, the reliability of feature extraction can be increased for various road lane patterns. Since outliers of edge at each block can be removed with clustering of edge orientation for each block within the ROI-LB, the performance of lane detection can be greatly improved. The various real road experimental results are presented to evaluate the effectiveness of the proposed method.