• Journal of Korea Society of Industrial Information Systems
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• v.12 no.5
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• pp.23-38
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• 2007

Since the players in online games seek fun, emotional aspects may be important factors in the pleasure-oriented information systems. This study attempted to verify the effects of characteristic factors of games (fun, challenge, compensation, and diversity) on emotion and customer satisfaction in game portal sites. The study established the research model on the foundation of precedent researches related to online games, emotion, and customer satisfaction. The study conducted online and offline survey on individuals with experiences in using online game portal sites. 206 samples were used to test the research hypotheses. By using Structural Equation Modeling, The study found the following results. First, it was revealed that characteristics of games had positive effects on emotion in game portal sites and indirect effects on user satisfaction. Second, the study analyzed the difference between low user group and high user group. It was revealed that the characteristics of games had positive effects on emotion in the low user group, but only challenge factor influenced on emotion in the high user group.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.4
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• pp.75-87
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• 2015

A redundant structure typically consists of primary component and standby component taking over the function of the primary component when the primary component fails. In this research, we consider a redundant structure in which a standby component can take over the function of more than one primary component when primary components fail. And we assume that the system has multi-state according to the states of components while all components have two states. This system is called as the multi-state redundant system with a multi-functional standby component. This type of redundant structure is frequently adapted by the system such as an aircraft in which the weight is an important design factor. In this paper, we propose new reliability model for this multi-state redundant system with a multi-functional standby component in order for evaluating the reliability of the system. Under the assumption that all components have constant failure rate, we evaluate the reliability of the system by applying Markov analysis method. And we investigate the effect of the multi-functional standby component by comparing reliabilities of the parallel system with multi-functional standby component and a simple parallel system and a parallel system with redundant structure.

• Molecules and Cells
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• v.38 no.10
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• pp.851-858
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• 2015

Disturbed blood flow with low-oscillatory shear stress (OSS) is a predominant atherogenic factor leading to dysfunctional endothelial cells (ECs). Recently, it was found that disturbed flow can directly induce endoplasmic reticulum (ER) stress in ECs, thereby playing a critical role in the development and progression of atherosclerosis. Ursodeoxycholic acid (UDCA), a naturally occurring bile acid, has long been used to treat chronic cholestatic liver disease and is known to alleviate endoplasmic reticulum (ER) stress at the cellular level. However, its role in atherosclerosis remains unexplored. In this study, we demonstrated the anti-atherogenic activity of UDCA via inhibition of disturbed flow-induced ER stress in atherosclerosis. UDCA effectively reduced ER stress, resulting in a reduction in expression of X-box binding protein-1 (XBP-1) and CEBP-homologous protein (CHOP) in ECs. UDCA also inhibits the disturbed flow-induced inflammatory responses such as increases in adhesion molecules, monocyte adhesion to ECs, and apoptosis of ECs. In a mouse model of disturbed flow-induced atherosclerosis, UDCA inhibits atheromatous plaque formation through the alleviation of ER stress and a decrease in adhesion molecules. Taken together, our results revealed that UDCA exerts anti-atherogenic activity in disturbed flow-induced atherosclerosis by inhibiting ER stress and the inflammatory response. This study suggests that UDCA may be a therapeutic agent for prevention or treatment of atherosclerosis.

• Molecules and Cells
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• v.40 no.1
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• pp.45-53
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• 2017

Aberrant hypermethylation of Wnt antagonists has been observed in gastric cancer. A number of studies have focused on the hypermethylation of a single Wnt antagonist and its role in regulating the activation of signaling. However, how the Wnt antagonists interacted to regulate the signaling pathway has not been reported. In the present study, we systematically investigated the methylation of some Wnt antagonist genes (SFRP2, SFRP4, SFRP5, DKK1, DKK2, and APC) and their regulatory role in carcinogenesis. We found that aberrant promoter methylation of SFRP2, SFRP4, DKK1, and DKK2 was significantly increased in gastric cancer. Moreover, concurrent hypermethylation of SFRP2 and DKK2 was observed in gastric cancer and this was significantly associated with increased expression of ${\beta}-catenin$, indicating that the joint inactivation of these two genes promoted the activation of the Wnt signaling pathway. Further analysis using a multivariate Cox proportional hazards model showed that DKK2 methylation was an independent prognostic factor for poor overall survival, and the predictive value was markedly enhanced when the combined methylation status of SFRP2 and DKK2 was considered. In addition, the methylation level of SFRP4 and DKK2 was correlated with the patient's age and tumor differentiation, respectively. In conclusion, epigenetic silencing of Wnt antagonists was associated with gastric carcinogenesis, and concurrent hypermethylation of SFRP2 and DKK2 could be a potential marker for a prognosis of poor overall survival.

• Journal of Preventive Medicine and Public Health
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• v.49 no.3
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• pp.153-164
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• 2016

Objectives: Previous studies have obtained conflicting findings regarding possible associations between indices measuring carbohydrate intake and dyslipidemia, which is an established risk factor of coronary heart disease. In the present study, we examined crosssectional associations between carbohydrate indices, including the dietary glycemic index (GI), glycemic load (GL), total amount of carbohydrates, and the percentage of energy from carbohydrates, and a range of blood lipid parameters. Methods: This study included 1530 participants (554 men and 976 women) from 246 families within the Healthy Twin Study. We analyzed the associations using a generalized linear mixed model to control for familial relationships. Results: Levels of the Apo B were inversely associated with dietary GI, GL, and the amount of carbohydrate intake for men, but these relationships were not significant when fat-adjusted values of the carbohydrate indices were used. Triglyceride levels were positively associated with dietary GI and GL in women, and this pattern was more notable in overweight participants (body mass index [BMI] ${\geq}25kg/m^2$). However, total, low-density lipoprotein and high-density lipoprotein cholesterol levels were not significantly related with carbohydrate intake overall. Conclusions: Of the blood lipid parameters we investigated, only triglyceride levels were positively related with dietary carbohydrate indices among women participants in the Healthy Twin Study, with an interactive role observed for BMI. However, these associations were not observed in men, suggesting that the association between blood lipid levels and carbohydrate intake depends on the type of lipid, specific carbohydrate indices, gender, and BMI.

• Journal of the military operations research society of Korea
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• v.34 no.1
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• pp.61-77
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• 2008

Data Envelopment Analysis(DEA) is a promising methodology to evaluate the relative efficiency of the decision-making units. We have compared the efficiency of six electric power generation companies in Korea using DEA. The analysis results by input-oriented CCR and BCC models are summarized as follows: first, different results were acquired between using input factors as total capacity of generators and as sub-totals of generator capacity based on primary energy sources. It is the result influenced by input factors which are characterized by the proportion of fixed costs(generating facilities) and variable costs(generation costs for primary energy), Second, the efficiency will be increased if the input factors selected, according to primary energy sources discussed in this research, are used during long-term expansion of electric power capacity plans. It is expected that this approach can give a feedback for management of electric power generation companies.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.312-317
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• 2009

Genome analysis of a model filamentous fungus, Aspergillus nidulans, revealed that there are six putative forkhead genes. Among them, fkhF (AN8949.2) showed A. nidulans-specific. fkhF gene is located in chromosome VII and composed of 2,337 bp coding region for 778 amino acid. Since little is known about the involvement of the forkhead proteins in the developmental process of the filamentous fungi, including A. nidulans, we generated a deletion mutant of fkhF gene and analyzed. Deletion of fkhF resulted in less-dense conidiophore formation in a solid culture. However, the sexual developmental process or cleistothecia formation was normal. Furthermore, fkhF deletion mutant produced conidiophores and conidia under the submerged culture, suggesting that the fkhF gene is involved in repression of inappropriated induction and maturation of asexual developmental process but not in sexual development.

• Korea Journal of Hospital Management
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• v.21 no.2
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• pp.50-62
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• 2016

The study was conducted to compare organizational innovation depending on the leadership type of middle managers in general hospital. Moreover, the study was also to prove whether employees'readiness causes any differences to the link between leadership and organizational innovation. The result is based on 769 sheets of survey paper answered by administrations and nurses working at general hospitals or the same level of hospitals located in the metropolitan area. The methods of analysis used are as follows: reliability analysis, frequency analysis, t-test, ANOVA, multiple regression analysis, and hierarchical regression analysis. Main results of the study can be summarized as below. First, by analyzing the influence of task-behavior leadership on organizational innovation, R squre on knowledge management which is organizational innovation factor was 12.5%, R squre on creativity was 9.1%, and R squre on innovation behavior was 10.3%. Regression model appeared to be statistically significant as well. Both task-behavior and relationship-behavior leadership have influence on organizational innovation and it is learned that relationship-behavior leadership has a bigger influence on all the organizational innovation factors. Second, moderating effect of the employee's readiness is examined in terms of the link between leadership and organizational innovation. As a result, the member's readiness had positive influence when it comes to the link between leadership and organizational innovation. Also, after verifying moderating effect of readiness (ability/willingness), this study shows that ability readiness has positive influence on the link between task-behavior(or relationship-behavior) leadership and creativity, and innovation behavior while willingness readiness positively influences the link between task-behavior(or relationship-behavior) leadership and creativity & innovation behavior. To summarize results of the study, this study shows that the members who possess high readiness also have high organizational innovation, which promises their positive role in a group.

• Korean Journal of Health Education and Promotion
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• v.25 no.1
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• pp.25-38
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• 2008

Objectives: This study identified the factors associated with successful smoking cessation for 6 months at a smoking-cessation clinic of a public health center in an urban area. Methods: The subjects of this study were 670 visitors to the smoking cessation clinic of Dongjak-Gu public health center in Seoul, from September 6, 2005 to March 24, 2006. The 274 visitors of them responded to the questionnaire with registration, which contained the information related to the study except that of registered card for the clinic. A dependent variable was success or failure in smoking cessation during the 6 month-smoking cessation program, measured the status of smoking cessation in each week by self-report. Independent variable included demographic information, the characteristics in using the clinic, health status and smoking related behaviour, exposure to other smokers in daily life and motivation. Multiple logistic regression model was used to find the factors associated with success of smoking cessation. Results: The success rate in smoking cessation for 6 months was 33.6%. Five pretreatment characteristics were identified as univariate predictors of continuous abstinence. Finally, age, job, and practice oriented motivation were associated significantly with the success of smoking cessation for 6 months from a multiple logistic regression analysis. The lower socio-economic smokers such as people having lower literacy level, lower income people, unskilled workers, and recipients by Medical Assistant Program were more likely to fail in continuous abstinence for 6 months. Conclusions: In order to increase the success rate in smoking cessation clinics of public centers, counselors should activate self confidence and practice oriented motivation of participants for smoking cessation.

• Physical Therapy Korea
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• v.14 no.3
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• pp.81-89
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• 2007

The purpose of this study was to utilize the K-MBI (Korean Modified Barthel Index) and subscales of K-MBI in predicting the length of hospital stay (LOS) and the discharge destinations for stroke patients. The study population consisted of 97 stroke patients (57 men and 40 women) admitted to the Seoul National University at the Bundang Hospital. All participants were assessed by K-MBI at admission and discharge after rehabilitation therapy and the information available was investigated at admission. The data were analyzed by using the Mann-Whitney U test, the stepwise multiple regression and the logistic regression. The median LOS was 30 days (mean, 32.8 days; range, 22 to 43 days). The K-MBI score at initiation of rehabilitation therapy (p<.001), the type of stroke and living habits before a stroke were the main explanatory indicators for LOS (p<.05). Within the parameters of K-MBI measured at initiation for rehabilitation, feeding and chair/bed transfer were the explanatory factors for LOS prediction (p<.01). Confidence in the prediction of LOS was 20%. Significant predictors of discharge destination in a logistic regression model were the discharge K-MBI score, sex and hemiplegic side. Dressing in items of discharge K-MBI was the significant predictor of discharge destination. The K-MBI score was the most important factor to predict LOS and discharge destination. Knowledge of these predictors can contribute to more appropriate treatment and discharge planning.