• Journal of Korea Water Resources Association
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• v.49 no.5
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• pp.439-450
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• 2016

For the design of infrastructures controlling the flood events at ungauged basins, this study tries to find the regional flood frequencies using peak flow data generated by the spatial extension of flood records. The Chungju Dam watershed is selected to validate the possibility of regional flood frequency analysis using the spatially extended flood data. Firstly, based on the index flood method, the flood event data from the spatial extension method is evaluated for 22 mid/smaller sub-basins at the Chungju Dam watershed. The homogeneity of the Chungju dam watershed was assessed in terms of the different size of watershed conditions such as accumulated and individual sub-basins. Based on the result of homogeneity analysis, this watershed is heterogeneous with respect to individual sub-basins because of the heterogeneity of rainfall distribution. To decide the regional probability distribution, goodness-of fit measure and weighted moving averages method from flood frequency analysis were adopted. Finally, GEV distribution was selected as a representative distribution and regional quantile were estimated. This research is one step further method to estimate regional flood frequency for ungauged basins.

• Environmental Mutagens and Carcinogens
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• v.22 no.2
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• pp.70-75
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• 2002

Gly460Trp polymorphism of a-adducin gene has been reported to be associated with hypertension in some populations, and we, therefore, attempted to replicate this finding in Korean population. There were no significant differences in allele and genotype frequencies of Gly460Trp polymorphism in Korean normotensives and hypertensives, respectively. The meta-analysis revealed that the Mantel-Haenszel estimate of the odds ratio across the studies was 1.17 (95%CI 1.04-1.31), and that there was significant evidence against homogeneity of the odds ratio among the studies included (Breslow-Day test = 27.34, df = 9, p = 0.001). Although the meta- analysis appeared in favour of association between the Gly4601tf polymorphism of $\alpha$-adducin gene and hypertension, there was the considerable heterogeneity among the studies and the evidence is also rather borderline. Further comprehensive approaches are needed to resolve this debatable issue.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.4
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• pp.149-160
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• 2018

An alternative method for team diversity studies is to examine demographic faultlines. A concept of demographic faultline enables us to better understand team dynamics with multidimensional diversity. This study suggests the demographic faultline as a new situational factorto influence the relationship between leader teamwork behaviors and a climate of support for innovation. When subgroups divided by demographic faultline are homogeneous within them and heterogeneous between them, the homogeneity may increase intimacy in each subgroup while the heterogeneity may increase exclusiveness between those subgroups. We argued that a leader could play an important role to build a cooperative relationship between faultline-based subgroups and highlight positive aspects of developing and maintaining subgroups in organizations. With a sample of 81 teams (558 employees), it was examined how leader teamwork behaviors would affect a team-level climate of support for innovation and how this relationship would be moderated by each team's demographic faultline (gender, age, and educational specialty). As predicted, it was found that there was a significant positive relationship between each leader's teamwork behaviors and each team's climate of support for innovation. In addition, this relationship was stronger for teams with strong faultline than with weak faultline. Our findings and their implications were further discussed.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.6
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• pp.120-129
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• 2007

Rapid urbanization has transformed the spatial pattern of urban land use or cover. This paper concentrates that changed characteristics of landscape structure in the Tancheon Watershed, from 1995 to 2003 were investigated using land cover map. We used FRAGSTATS software to calculate landscape indices to characterize the landscape structure. We found that built up area has been increased rapidly during the study period, while cultivated area and forest area have been decreased rapidly in the same period. From 1995 to 2003, built up area was increased from 19.73% to 39.62% and cultivated area and forest area was decreased 17.60% to 5.97% and 58.31% to 49.41%. Number of patches, mean euclidean nearest-neighbor distance, contagion index, Shannon's diversity index increased considerably from 1995 to 2003, also suggesting the landscape in the study area became more fragmented and heterogeneous. but because of continuously fragmentation, landscape became homogeneity. The study demonstrates that landscape metrics can be a useful indicator in landscape monitoring and landscape assessment.

• Journal of Digital Contents Society
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• v.19 no.7
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• pp.1389-1395
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• 2018

Hybrid is explained based on the logic of combination such as cross, melding, permeation, fusion, convergence etc. Such combination shows that it is more creative and effective in case of heterogeneity as compared to homogeneity and the same kind, and hybrid character has its meaning as a mean to produce a new creative image. In the context, this study aims to analyze influencing relationship through a practical analysis on how formative requirements for hybrid characters affects consumer preference. For the foregoing, this study conducted multiple regression analysis having familiarity, originality, meaningfulness, diversity as independent variables for formative requirements for characters, and consumer preference as a dependent variable. Analysis results show that familiarity, originality, diversity have a positive effect on consumers, whereas, meaningfulness has no significant impact on the consumer preference.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.23-31
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• 2020

This paper investigates the impact of monetary policy independence shock on bond yield by allowing for heterogeneous coefficients in the model based on panel data for 19 developing countries using quarterly data from 1991 to 2016. First, we estimate the model using conventional panel VAR estimation with the assumption of homogeneous coefficients across countries. Second, by performing Chow and Roy-Zellner tests to check the homogeneity assumption, we find that the assumption does not hold in the model. Third, we apply a mean-group estimation for panel VAR as a solution for heterogeneity panel model. The results reveal that central bank independence is effective in reducing bond yield with the maximum at period 6 after the shock. Shock one standard deviation bond yield has a negative effect on consumption and investment. We determine that central bank independence has a contradictory effect on real activity; a negative effect on consumption but a positive influence on investment for the first two years after the shock. Additionally, we split our sample into three groups to make the subgroups pool. Our empirical result shows that monetary policy independence shock reduces bond yield. Meanwhile, the response of economic activity to bond yield varies for all three groups.

• Clinical and Experimental Pediatrics
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• v.65 no.3
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• pp.131-135
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• 2022

Purpose: There is inconsistent evidence about the association between fetal nuchal cord and the risk of autism spectrum disorder (ASD). We performed a meta-analysis to investigate whether fetal nuchal cord is associated with an increased risk of ASD in offspring. Methods: Three main English databases were searched until January 2021. The Newcastle-Ottawa Scale was used to assess study quality. Study heterogeneity was determined using the I 2 statistic, while publication bias was assessed using Begg and Egger tests. Results are presented as odds ratios (ORs) and relative ratios with 95% confidence intervals (CI) and were determined by a random-effects model. Results: Five articles (1 cohort, 4 case-control; 3,088 total children) were included in the present meta-analysis. Fetal nuchal cord was not a risk factor for ASD (OR, 1.11; 95% CI, 0.66-1.57). There was homogeneity among studies that reported a risk of ASD (I²=0.0%). Conclusion: Our results showed that fetal nuchal cord is not a risk factor for ASD. Future large cohort studies should confirm this finding.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.658-660
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• 2021

The work within this study develops an algorithm based on the structural similarity index to assess numerically between reconstructed images with a reference image to separate the homogeneity and heterogeneity for diffuse optical tomography. Global geometry and region of interest assessment have been measured to yield the similarity. The results indicate that the mean of structural similarity index shows potential performance to distinguish between visible and invisible inclusion inside the model. Therefore, the structural similarity index may promise to assist the image assessment for evaluating breast structural information.

• Asia pacific journal of information systems
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• v.23 no.2
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• pp.67-86
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• 2013

This study first provides a stylized model that captures the essential features of the SC (Social Commerce) business and the competition process. The model focuses on the relationship between key decision issues such as marketing inputs and market value. As more SCs join the industry, they are inevitably faced with fierce competition, which may lead to sharp increase in the total marketing and advertising expenditure. This type of competition may lead the industry away from its optimal development path, and at worst, toward a disruption of the entire industry ecosystem. Such being the case, another goal of this study is to examine the possibility that the ToC (Tragedy of the Commons) may occur in the SC industry. We build game models, each of which assumes homogeneity and heterogeneity of SC providers, respectively, and derive explicit equilibrium solutions from both models. Our basic analysis presents Nash equilibria in both models and shows that SC providers are inevitably faced with fierce competition, which may lead to sharp increase in the total marketing expenses. We also compare the game outcomes with one with a hypothetical social planner who determines the total marketing level that optimizes the entire market value. Then, ToC can be defined to describe the situation where the total marketing efforts exceed the socially optimal level of marketing efforts. In both models, we examine the possibility of the ecosystem disruption and specify the conditions under which ToC may occur. However, the chance of avoiding ToC is higher with heterogeneous players than with homogeneous players. To supplement our analytical results, we develop a simulation model which incorporates a market dynamics based on the gap between actual marketing efforts and socially optimal marketing level. Simulation experiments present some lessons and insights which also confirm out findings from equilibrium analysis. For example, heterogeneity in SC providers alleviates the severity of ToC and makes it faster for survivors to escape from the ToC trap. As a result, the degree of industrial concentration tends to increase, which also explains the 'rich-get-richer' phenomenon observed in some empirical studies on the SC industry. Lastly, based on our analytical and experimental results, we come up with some measures to avoid ToC and overcome the shortcomings intrinsic to the current business model. And further discussions provide strategic implications and policy directions to overcome the possible trap of ToC in this ecosystem, and eventually help the industry to sustainably develop itself toward the next level. To name a few examples of policy measures, regulations on the marketing activities so that the overall marketing expenses cannot go beyond the socially optimal level; institutional guidelines and rules to straightening up the distortions in the way that SC providers view the marketing costs (the current marketing costs are underestimated, thereby encouraging SC providers to increase marketing expenditure); and so on.

• Korean Journal of Clinical Pharmacy
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• v.22 no.3
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• pp.220-227
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• 2012

Kidney and liver are the major organs of metabolism and excretion of drugs. Renal and Hepatic impairment may affect the pharmacokinetics/pharmacodynamics and the safety of drugs. Adjusting the dosage based on organ function is the essential role of pharmacists. However, differences have been noted on the recommended dosage among the literatures. We compared and analyzed the recommendations of 4 literature sources which are commonly used for dosage adjustment. From April, 2011 to August, 2011, we selected data on recommendations for dosage adjustment for impaired renal and hepatic function of 100 drugs through a protocol. We analyzed the definition terms of renal and hepatic impairment, recommendations for dosage adjustment, evidenced references in four literature sources: Korean National Formulary (KNF), American Hospital Formulary System Drug Information (AHFS), Micromedex (MM) and Drug Prescribing of Renal Failure (DPRF). We further examined the data homogeneity by comparing how drugs that required no adjustment according to one source were categorized by the other. Sources use different definition terms among themselves except DRPF. Presence or absence of evidenced references about renal/hepatic functional states are KNF (0%/0%), AHFS (78%/62.6%), MM (87.5%/65.6%) and DPRF (93.2%/no recommendation) respectively. Recommendations of specific dosage and dosing interval are KNF (24%/13%), AHFS (39.6%/12.1%), MM (50%/17.7%), and DPRF (55.4%/no recommendation) respectively. Regarding the data homogeneity, the differences were remarkable. Drugs with no adjustment according to AHFS were categorized to be adjusted/ contraindicated by KNF, MM, DPRF and the values were (44%/5.6%), (22%/0%), and (36%/0%) in renal function, (39%/6.5%), (19%/3.2%), and (no recommendation/no recommendation) in hepatic function respectively. Our study shows remarkable definite variation in definitions and recommendations about definition terms, information of dosage and interval, presence or absence of evidenced references. Especially for KNF, quantitative recommendations on dosages and dosing intervals should be made in the near future. To maximize the drug effect and safety and to minimize the heterogeneity of the literature sources, reviewing at least two sources are suggested when recommending the proper dosage adjustment based on organ function.