• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5311-5316
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• 2013

A functional polymorphism in the NQO1 gene, featuring a 609C>T substitution,leading to proline to serine amino-acid and enzyme activity changes, has been implicated in cancer risk. However, individually published investigations showed inconclusive results, especially for leukemia. In this study, we therefore performed a meta-analysis of 21 publications with a total of 3,634 cases and 4,827controls, mainly for leukemia. We summarized the data on the association between the NQO1 609C>T polymorphism and risk of leukemia and performed subgroup analyses by ethnicity and leukemia type. We found that the variant TT homozygous genotype o was associated with a modestly increased risk of leukemia (TT versus CT/CC: OR=1.23, 95%CI=1.00-1.51, heterogeneity=0.76; $I^2$=0%). Following further stratified analyses, increased risk was only observed in subgroups of Caucasians. This meta-analysis suggests that the NQO1 609T allele is a high-penetrance risk factor for leukemia in Caucasians. The effect on leukemia may be modified by ethnicity and leukemia type, and the small sample sizes of the subgroup analyses suggest that further larger studies are needed.

• Journal of The Korean Association of Information Education
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• v.6 no.3
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• pp.317-327
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• 2002

The need to support the ICT-using teaching and learning at elementary and secondary schools has led to various digital content service systems. The systems are designed to target the teachers and the students as the major users. The problems involved in them is that they do not provide such services as the integrated search and the systematic use of interface in terms of actual users' use of teaching and learning digital content. It's because they have been created at demands at each time. In an attempt to solve this problem, this study set out to suggest the integrated meta-data items of a teaching and learning digital content, which reflects the Dublin Core Education, the international meta-data standard. It also aimed to design an entity-relationship model to realize the digital content. The results of the integrated meta-data and the entity-relationship model will be utilized as a basic research to help the users to search for various teaching and learning digital contents on an integrated basis and to realize a consistent user interface. Furthermore, they are expected to contribute to the development a service system the teachers and the students can make better use of.

• Journal of the Korean Society for information Management
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• v.21 no.3
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• pp.203-225
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• 2004

This study is to investigate the characteristics of the Invisible Web and many search services designed to serve as gateways to the Invisible Web and to evaluate searching the Invisible Web in the Services. The four services for searching the Invisible Web were selected to search the Invisible Web with 11 queries, that are Google as portals, ProFusion and Search.com as Invisible Web meta search engines, and IncyWincy as Invisible Web search engines. It was found that the effectiveness of Google's Invisible Web searching was better compared with the three Invisible Web search tools but the difference between the four systems was not significant((${\alpha}$=.055) The Invisible Web meta searching was better than the Web meta searching in the three search tools at the statistically significant level. The effectiveness measurement based on the ranks and relevance degree(quality) of relevant documents retrieved seemed appropriate to the ranked search results.

• Journal of Preventive Medicine and Public Health
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• v.46 no.1
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• pp.10-18
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• 2013

Objectives: We investigated the association between particulate matter less than $10{\mu}m$ in aerodynamic diameter ($PM_{10}$) exposure and non-accidental mortality in Asian populations by meta-analysis, using both time-series and case-crossover analysis. Methods: Among the 819 published studies searched from PubMed and EMBASE using key words related to $PM_{10}$ exposure and non-accidental mortality in Asian countries, 8 time-series and 4 case-crossover studies were selected for meta-analysis after exclusion by selection criteria. We obtained the relative risk (RR) and 95% confidence intervals (CI) of non-accidental mortality per $10{\mu}g/m^3$ increase of daily $PM_{10}$ from each study. We used Q statistics to test the heterogeneity of the results among the different studies and evaluated for publication bias using Begg funnel plot and Egger test. Results: Testing for heterogeneity showed significance (p<0.001); thus, we applied a random-effects model. RR (95% CI) per $10{\mu}g/m^3$ increase of daily $PM_{10}$ for both the time-series and case-crossover studies combined, time-series studies relative risk only, and case-crossover studies only, were 1.0047 (1.0033 to 1.0062), 1.0057 (1.0029 to 1.0086), and 1.0027 (1.0010 to 1.0043), respectively. The non-significant Egger test suggested that this analysis was not likely to have a publication bias. Conclusions: We found a significant positive association between $PM_{10}$ exposure and non-accidental mortality among Asian populations. Continued investigations are encouraged to contribute to the health impact assessment and public health management of air pollution in Asian countries.

• Journal of Preventive Medicine and Public Health
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• v.53 no.3
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• pp.151-157
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• 2020

Objectives: The outbreak of coronavirus disease 2019 (COVID-19) is one of the main public health challenges currently facing the world. Because of its high transmissibility, COVID-19 has already caused extensive morbidity and mortality in many countries throughout the world. An accurate estimation of the basic reproduction number (R₀) of COVID-19 would be beneficial for prevention programs. In light of discrepancies in original research on this issue, this systematic review and meta-analysis aimed to estimate the pooled R₀ for COVID-19 in the current outbreak. Methods: International databases (including Google Scholar, Science Direct, PubMed, and Scopus) were searched to identify studies conducted regarding the R₀ of COVID-19. Articles were searched using the following keywords: "COVID-19" and "basic reproduction number" or "R₀." The heterogeneity among studies was assessed using the I² index, the Cochran Q test, and T². A random-effects model was used to estimate R₀ in this study. Results: The mean reported R₀ in the identified articles was 3.38±1.40, with a range of 1.90 to 6.49. According to the results of the random-effects model, the pooled R₀ for COVID-19 was estimated as 3.32 (95% confidence interval, 2.81 to 3.82). According to the results of the meta-regression analysis, the type of model used to estimate R₀ did not have a significant effect on heterogeneity among studies (p=0.81). Conclusions: Considering the estimated R₀ for COVID-19, reducing the number of contacts within the population is a necessary step to control the epidemic. The estimated overall R₀ was higher than the World Health Organization estimate.

• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.573-579
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• 1996

Effects of operating variables on the conversion of the formation reaction of meta boric acid from ortho boric acid in a laboratory-scale bubble column reactor were investigated to obtain the basic data which are indispensable for the design, scale-up, control, development and operation of industrial bubble column reactors. Reaction time and pressure, particle size of reactant and gas flow rate were chosen as experimental variables. Effects of the experimental variables on the gas holdup in the bubble column reactor were also discussed in relation to the conversion of reaction. From the results of this study, the optimum conditions were drawn as follows : Reaction time ; 35~40(min), reaction pressure ; 92~95(kPa), particle size ; under $0.6{\times}10^{-3}(m)$, gas flow rate ; 0.07~0.08(m/s).

• The Journal of the Korea Contents Association
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• v.15 no.11
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• pp.359-373
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• 2015

Cognitive reserve(CR) is the ability to optimize or maximize performance through complementary brain networks. CR is relevant to normal aging in cognitive-linguistic abilities. There are few domestic systematic reviews or meta-analyses that analyze the relationships between multiple CR and cognitive-linguistic domains in healthy older people. This meta-analysis included 32 studies published since 2000. In result, education level topped the list, followed by the occupation, cognitively stimulating activities, and the multilingualism. Most studies were related to memory, global cognition, and language. CR had a modest positive association with cognitive-linguistic performance. Multiple domains including memory and language also showed the significant correlations across most measures of CR. This study provides evidence-based information to support cognitive-linguistic ability in normal aging.

• Safety and Health at Work
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• v.11 no.2
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• pp.136-142
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• 2020

Background: Rheumatoid arthritis (RA) is an autoimmune disease with systemic inflammatory arthritis. This meta-analysis was conducted to examine the association between occupational exposure to silica and the risk of developing RA among different workers. Methods: In this meta-analysis, we searched relevant published studies using major electronic databases including Scopus, PubMed, ISI Web of Science, and Google Scholar search engine up to October 2019, and the references of retrieved articles were also checked for further possible sources. A random-effects model was used to account for heterogeneity among the results of the studies using the pooled odds ratios (ORs) and their 95% confidence intervals (CIs). The Q-statistic and I² tests were calculated to assess heterogeneity between the studies. Results: The pooled calculation of OR indicated a significant association between occupational exposure to silica and risk of developing RA among different workers (OR = 2.59, 95% CI = 1.73 to 3.45). In addition, the pooled estimates of OR in smokers were statistically significant (OR = 2.49, 95% CI = 1.13 to 3.86). Conclusions: The findings of the present study reveal that occupational exposure to silica may be associated with increased risk of developing RA.

• Journal of Digital Convergence
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• v.13 no.7
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• pp.293-304
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• 2015

Meta-analysis was conducted to examine effects of computer based virtual reality on clinical rehabilitation in Korea. The data were analyzed as the ICF categorizations. The papers used in this study were located through domestic data search engines. The fifteen studies were selected among the studies published between 1995 and 2014. The PEDro score was used for qualitative assessment. The sample size and the average and standard deviations of pre and post tests were analyzed through a meta-analysis. The PEDro scores of the selected studies were 6 points higher and 338 participants were involved. The effect size of combined data was 1.030, activities and participation 1.120, sensory function 1.199 as indicated by a "large effect size" and the effect size of mental function was 0.557 as indicated by a "medium effect size." As a result, virtual reality program as a adjunctive therapeutic methods has proven the effect. In particular, the effects were demonstrated in activities and participation, sensory function. However there was no evidence of the effectiveness of mental function.

• Journal of Digital Contents Society
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• v.6 no.4
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• pp.201-208
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• 2005

In high-technology digital age that change everyday fast, Web became most familiar and essential tool to public. Since creation of web, web began from the first step web that offer simple information and contents. and now, it have developed to step offer dynamic contents that various multimedia components are combined. In future, it will develop to the next generation, intelligence style Semantic Web that Meta Communication of meaning-base is possible. In this paper, we examine about concept and characteristic of Semantic web that is a point technology in next generation. Also, we studied about example and practical use in personalized contents side that is based on Semantic Meta-Communication system. Semantic web is value industry field that has infinite possibility and has necessary of a lot of studies and development yet. Therefore in digital age, we expect this paper will help for space construction of more mature communication.