• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.360-370
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• 2013

As the mobile telecommunications service market grows rapidly, interconnection opportunities from the fixed network to the mobile network increase and the land-to-mobile (LM) interconnection charge becomes critical factor in competition between fixed and mobile telecommunications service providers. This paper aims to evaluate the LM interconnection charge level in Korea in comparison with those of 36 foreign countries and suggest the regression model for the LM interconnection charge. Based on the regression analysis, we found that regulation, GDP per capita, wire telephone penetration, liberalization are identified as significantly affecting factors on the LM interconnection charge level, and the level of the LM interconnection charge is comparatively low.

• The Journal of the Korea Contents Association
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• v.13 no.8
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• pp.201-210
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• 2013

The purpose of this study is to verify the effects on all factors from the research design by pastors. Research model is based on the theory of planned behavior. To this end, data were collected from 214 pastors and they were analyzed. In order to derived the results of a study, we used the statistical processing technique SPSS, to perform verification of factor analysis and reliability of each variable, AMOS analysis was performed for hypothesis testing. The results are as follows. First, this study demonstrated that there is a positive relationship between subjective norms and intention, perceived behavior control and intention of retirement preparing. Second, this study demonstrated that there is a positive relationship between intention and behavior, perceived behavior control and behavior of retirement preparing. Third, intention had a partial mediation effect between perceived behavior control and behavior of retirement preparing. As a result of this research, comprehensive implications were suggested for improving of retirement preparing by pastor.

• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.98-105
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• 1999

Intestinal bacteria comprise one-third of the contents of the large intestine in humans. Their interactions with the gastrointestinal immune system induce characteristic immunological responses which stimulate or suppress the host's defense system. RAW 264.7 murine cell line was used as a macrophage model to assess the effects of the exposure to the isolated human intestinal bacteria, Bacteroides, Bifidobacterium, Eubacterium, Streptococcus, and E. coli, on NO (nitric oxide), $H_2O_2$(hydrogen peroxide), and cytokines IL (interleukin)-6 and TNF (tumor necrosis factor)-a production. RAW 264.7 cells were cultured in the presence of heat-killed bacteria for 24 h at concentrations of 0-$50\mu$g/ml. Our results showed that Bacteroides and E. coli stimulated IL-6, TNF-$\alpha$, NO, and $H_2O_2$production at high levels even at $1\mu$g/ml, whereas Bifidobacterium, Eubacterium, and Streptococcus showed a low level of stimulation at $1\mu$g/ml, and a gradual increase as the cell concentration increased up to $50\mu$g/ml. This result suggests that gram-negative Bacteroides and E. coli are better able to stimulate macrophage than gram-positive Bifidobacterium, Streptococcus, and Eubacterium. The in vitro approaches employed here should be useful in further characterization of the effects of intestinal bacteria on gastrointestinal and systemic immunity.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.270-282
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• 2008

The yeast Saccharomyces cerevisiae has defense mechanisms identical to higher eukaryotes. It offers the potential for genome-wide experimental approaches owing to its smaller genome size and the availability of the complete sequence. It therefore represents an ideal eukaryotic model for studying cellular redox control and oxidative stress responses. S. cerevisiae Yap1 is a well-known transcription factor that is required for $H_2O_2$-dependent stress responses. Yap1 is involved in various signaling pathways in an oxidative stress response. The Gpx3 (Orp1/PHGpx3) protein is one of the factors related to these signaling pathways. It plays the role of a transducer that transfers the hydroperoxide signal to Yap1. In this study, using extensive proteomic and bioinformatics analyses, the function of the Gpx3 protein in an adaptive response against oxidative stress was investigated in wild-type, gpx3-deletion mutant, and gpx3-deletion mutant overexpressing Gpx3 protein strains. We identified 30 proteins that are related to the Gpx3-dependent oxidative stress responses and 17 proteins that are changed in a Gpx3-dependent manner regardless of oxidative stress. As expected, $H_2O_2$-responsive Gpx3-dependent proteins include a number of antioxidants related with cell rescue and defense. In addition, they contain a variety of proteins related to energy and carbohydrate metabolism, transcription, and protein fate. Based upon the experimental results, it is suggested that Gpx3-dependent stress adaptive response includes the regulation of genes related to the capacity to detoxify oxidants and repair oxidative stress-induced damages affected by Yap1 as well as metabolism and protein fate independent from Yap1.

• Journal of Microbiology and Biotechnology
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• v.27 no.6
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• pp.1180-1188
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• 2017

Neuronatin (NNAT) is known to regulate ion channels during brain development and plays a role in maintaining the structure of the nervous system. A previous in silico analysis showed that Nnat was overexpressed in the adipose tissue of an obese rodent model relative to the wild type. Therefore, the aim of the present study was to investigate the function of Nnat in the adipose tissue. Because obesity is known to systemically induce low-grade inflammation, the Nnat expression level was examined in the adipose tissue obtained from C57BL/6 mice administered lipopolysaccharide (LPS). Unexpectedly, the Nnat expression level decreased in the white adipose tissue after LPS administration. To determine the role of NNAT in inflammation, 3T3-L1 cells overexpressing Nnat were treated with LPS. The level of the p65 subunit of nuclear factor-kappa B ($NF-{\kappa}B$) and the activity of $NF-{\kappa}B$ luciferase decreased following LPS treatment. These results indicate that NNAT plays an anti-inflammatory role in the adipose tissue.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1800-1805
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• 2018

Inflammatory bowel disease, including Crohn's disease and ulcerative colitis (UC), is a chronically relapsing inflammatory disorder of the gastrointestinal tract. Intestinal epithelial cells (IECs) constitute barrier surfaces and play a critical role in maintaining gut health. Dysregulated immune responses and destruction of IECs disrupt intestinal balance. Dextran sodium sulfate (DSS) is the most widely used chemical for inducing colitis in animals, and its treatment induces colonic inflammation, acute diarrhea, and shortening of the intestine, with clinical and histological similarity to human UC. Current treatments for this inflammatory disorder have poor tolerability and insufficient therapeutic efficacy, and thus, alternative therapeutic approaches are required. Recently, dietary supplements with probiotics have emerged as promising interventions by alleviating disturbances in the indigenous microflora in UC. Thus, we hypothesized that the probiotic Bifidobacterium animalis subsp. lactis strain BB12 could protect against the development of colitis in a DSS-induced mouse model of UC. In the present study, oral administration of BB12 markedly ameliorated DSS-induced colitis, accompanied by reduced tumor necrosis factor-${\alpha}$-mediated IEC apoptosis. These findings indicate that the probiotic strain BB12 can alleviate DSS-induced colitis and suggest a novel mechanism of communication between probiotic microorganisms and intestinal epithelia, which increases intestinal cell survival by modulating pro-apoptotic cytokine expression.

• Environmental Engineering Research
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• v.20 no.4
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• pp.347-355
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• 2015

The growth kinetics of phototrophic microorganisms can be controlled by the light irradiance, the concentration of an inorganic nutrient, or both. A multi-component kinetic model is proposed and tested in novel batch experiments that allow the kinetic parameters for each factor to be estimated independently. For the cyanobacterium Synechocystis sp. PCC6803, the estimated parameters are maximum specific growth rate $({\mu}_{max})=2.8/d$, half-maximum-rate light irradiance $(K_L)=11W/m^2$, half-inhibition-rate light irradiance $(K_{L,I})=39W/m^2$, and half-maximum-rate concentration for inorganic carbon $(K_{S,Ci})=0.5mgC/L$, half-maximum-rate concentration for inorganic nitrogen $(K_{S,Ni})=1.4mgN/L$, and half-maximum-rate concentration for inorganic phosphorus $(K_{S,Pi})=0.06mgP/L$. Compared to other phototrophs having ${\mu}max$ estimates, PCC6803 is a fast-growing r-strategist relying on reaction rate. Its half-maximum-rate and half-inhibition rate values identify the ranges of light irradiance and nutrient concentrations that PCC6803 needs to achieve a high specific growth rate to be a sustainable bioenergy source. To gain the advantages of its high maximum specific growth rate, PCC6803 needs to have moderate light illumination ($7-62W/m^2$ for ${\mu}_{syn}{\geq}1/d$) and relatively high nutrient concentrations: $N_i{\geq}2.3 mgN/L$, $P_i{\geq}0.1mgP/L$, and $C_i{\geq}1.0mgC/L$.

• Journal of the Korean Society for information Management
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• v.26 no.4
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• pp.249-276
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• 2009

The purpose of this study is to investigate the information-seeking procedure of surveillants against public sector organizations in Korea. The surveillants used accountability mechanisms such as National Assembly Inspection and information disclosure to find out information they wanted. Examples of such group include social activists, professional supervisors, aides of the National Assembly congressman and the press members. Using data collected by in-depth interviews and participative observations, we studied their information seeking behaviors and factors that affect the procedure. Based on the Grounded Theory approach, we first generated 56 concepts, 17 categories and 6 super-categories about the participants' feeling, experiences and perception related to their information seeking. Then we developed a factor model among those generated concepts. The main contributions of this study are a) the results provide a useful guidance for the public information seekers b) we draw the requirements for enhancing public sector organizations' information management systems.

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.73-83
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• 2014

This paper is to analyse how Industree Crafts, social enterprise in the field of crafts, could generate profit and create a sustainable growth for the last 30 years out of dependence on government grants in India. Success factors was drawn from the findings as follows. First, bringing stakeholder value: it preferred social mission as a goal for generating the value of stakeholders respectively and shared value mutually. Second, building distinctive internal business processes: it adapted unique business model and 4P strategy into its internal organization system and introduced the way of management to support the independence of self-help groups aimed at creating greater added value. Third, promoting learning and innovation culture: it challenged with the help of new design strategies continuously, was unafraid of change, and promoted learning culture to turn trial and error into the organization learning. Finally fourth, securing right finances and resources: it obtained proper finances and resources such as trying joint-sale, attracting investment from a private company, and acquiring enough skilled artisans at every scaling up.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.951-953
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• 2007

Generation of Corporate risk Contents using Financial Data The purpose of this paper is to capture risk profiles of smaller-sized Korean firms vis-$\grave{a}$-vis larger-sized firms during the Asian financial crisis. For this purpose, risk profiles are provided by estimating expected default risks and by tracking how these have changed during this period with respect to their magnitude, volatility, and sensitivity measures. Methodology used in this study employs the Black-Scholes-Merton model for producing estimates of default risks. And the conventional trans-log function is utilized for obtaining sensitivity measures of the estimated default risks. According to empirical evidence obtained here, it is revealed that contractions of corporate loans associated with IMF austerity policy was the main factor responsible for the drastic change in the default risk profile of Korean firms after occurrence of the Asian financial crisis.