• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1375-1387
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• 2016

The purpose of this study was to evaluate the effect of exercise on cognitive function in the elderly through a systematic literature review and meta-analysis. For the study purpose, 14 studies were selected through a systematic process of using several databases and 11 studies were used to estimate the effect size of exercise on cognitive function. Meta-analysis was performed using a random effects model, and the effect size on cognitive function was calculated. The effect size for cognitive function of exercise intervention was Hedges' g=1.05 (95% CI: 0.61~1.50), indicating a large effect size. For heterogeneity, moderator analysis was performed using intervention, number of times per week, intervention duration, and cognitive function measurement. Cognitive function measurement was statistically significant, the other moderators did not significant difference. Results support that exercise has significant positive effects on cognitive function in elderly in korea. It also provided a basis that can be applied to exercise intervention design for cognitive function.

• Journal of Environmental Health Sciences
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• v.40 no.5
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• pp.385-396
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• 2014

Objectives: By conducting a meta-analysis of cohort studies reporting standardized mortality ratios (SMRs) for workers exposed to trichloroethylene, we attempted to adjust for healthy hired effect by applying the same methods as described in a recent report from the Agricultural Health Study. Methods: Among all cohort studies that evaluated the association between all cancer, non-Hodgkin's lymphoma (NHL), kidney cancer, liver cancer and occupational exposure to trichloroethylene, a total of 10 studies reporting SMR values were selected. A random-effects model was used to estimate the summary SMRs or rSMRs and 95% confidence intervals. Relative SMR ($rSMR=SMR_x/SMR_{not\;x}$) was calculated comparing observed and expected counts for all cancer, NHL, kidney cancer, and liver cancer with an independent referent set of values consisting of the observed and expected counts for other causes. Results: The SMR values for all causes ranged from 0.68 to 1.03, suggesting moderate to weak healthy worker effect for the selected studies. When the healthy worker hire effect was taken into account, the summarized risk became statistically significant; the summary SMR of all cancer was 0.95 (0.91-1.00) and the summary rSMR of all cancer was 1.10 (1.04-1.15). The summary SMR of NHL was 1.04 (0.93-1.14) and the summary rSMR of NHL was 1.23 (1.04-1.46). The summary SMR of kidney cancer was 1.08 (0.88-1.33) and the summary rSMR of kidney cancer was 1.23 (1.02-1.49). The summary SMR of liver cancer was 0.88 (0.78-0.99), and the summary rSMR of liver cancer was 0.95 (0.84-1.07). Conclusion: The rSMR method is useful to determine summary risk adjusted for healthy worker effect through meta-analysis.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.303-310
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• 2015

The study was conducted to analyze the genetic parameters of somatic cell score (SCS) of Holstein cows, which is an important indicator to udder health. Test-day records of somatic cell counts (SCC) of 305-day lactation design from first to fifth lactations were collected on Holsteins in Korea during 2000 to 2012. Records of animals within 18 to 42 months, 30 to 54 months, 42 to 66 months, 54 to 78 months, and 66 to 90 months of age at the first, second, third, fourth and fifth parities were analyzed, respectively. Somatic cell scores were calculated, and adjusted for lactation production stages by Wilmink's function. Lactation averages of SCS ($LSCS_1$ through $LSCS_5$) were derived by further adjustments of each test-day SCS for five age groups in particular lactations. Two datasets were prepared through restrictions on number of sires/herd and dams/herd, progenies/sire, and number of parities/cow to reduce data size and attain better relationships among animals. All LSCS traits were treated as individual trait and, analyzed through multiple-trait sire models and single trait animal models via VCE 6.0 software package. Herd-year was fitted as a random effect. Age at calving was regressed as a fixed covariate. The mean LSCS of five lactations were between 3.507 and 4.322 that corresponded to a SCC range between 71,000 and 125,000 cells/mL; with coefficient of variation from 28.2% to 29.9%. Heritability estimates from sire models were within the range of 0.10 to 0.16 for all LSCS. Heritability was the highest at lactation 2 from both datasets (0.14/0.16) and lowest at lactation 5 (0.11/0.10) using sire model. Heritabilities from single trait animal model analyses were slightly higher than sire models. Genetic correlations between LSCS traits were strong (0.62 to 0.99). Very strong associations (0.96 to 0.99) were present between successive records of later lactations. Phenotypic correlations were relatively weaker (<0.55). All correlations became weaker at distant lactations. The estimated breeding values (EBVs) of LSCS traits were somewhat similar over the years for a particular lactation, but increased with lactation number increment. The lowest EBV in first lactation indicated that selection for SCS (mastitis resistance) might be better with later lactation records. It is expected that results obtained from these multi-trait lactation model analyses, being the first large scale SCS data analysis in Korea, would create a good starting step for application of advanced statistical tools for future genomic studies focusing on selection for mastitis resistance in Holsteins of Korea.

• The Journal of the Korea Contents Association
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• v.13 no.5
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• pp.342-353
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• 2013

Objectives: It attempted to analyze influencing factors on the utilization of outpatient services which were adopted to predisposing, enabling, and need factors in Anderson model. Methods: The current study analyzed "2007 Korean National Health Nutrition Survey" data, which selected 3,335 people nationwide by proportional systematic sampling. This study analyzed data of persons who used outpatient services in two weeks. It adopted Anderson Model to control contextual factors including socioeconomic factors. The study compared means and fitted logistic regression models and multilevel model. Results: The logistic regression model showed that persons purchased private medical insurance were less likely to use outpatient services than the persons did not purchase private medical insurance. Persons with hypertension and diabetes mellitus, overweight, and problem drinkers were more likely to use outpatient services. Persons with high school graduates or higher in education level and experience of accidents or intoxications were more likely to use outpatient services according to the multilevel analysis of mixed model which treated region as random effect. Conclusion: Higher level of perceived stress increased the probability to use outpatient service than lower level of perceived stress. As number of days a person had exercised increased, the probability to use outpatient service decreased. Overweight and problem alcohol drinking increased the probability of outpatient service use. Further research should be conducted to find more factors influencing outpatient service use.

• The Mathematical Education
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• v.61 no.2
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• pp.257-271
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• 2022

As information and communication technologies are being developed so rapidly, education research is actively conducted to provide optimal learning for each student using big data and artificial intelligence technology. In this study, using the mathematics learning data of elementary school 5th to 6th graders conducting blended mathematics classes, we tried to find out what factors predict mathematics academic achievement and developed an artificial intelligence model that predicts mathematics academic performance using the results. Math learning propensity, LMS data, and evaluation results of 205 elementary school students had analyzed with a random forest model. Confidence, anxiety, interest, self-management, and confidence in math learning strategy were included as mathematics learning disposition. The progress rate, number of learning times, and learning time of the e-learning site were collected as LMS data. For evaluation data, results of diagnostic test and unit test were used. As a result of the analysis it was found that the mathematics learning strategy was the most important factor in predicting low-achieving students among mathematics learning propensities. The LMS training data had a negligible effect on the prediction. This study suggests that an AI model can predict low-achieving students with learning data generated in a blended math class. In addition, it is expected that the results of the analysis will provide specific information for teachers to evaluate and give feedback to students.

• Journal of Korea Technology Innovation Society
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• v.21 no.2
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• pp.522-559
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• 2018

In this study, we reviewed and analyzed the influencing factors of technology transfer performance in the previous studies (52 domestic journals and theses) and classified the various influencing factors into 6 top factors and 13 sub-factors based on the theoretical background. The study results of previous articles were analyzed by meta-analysis method so as to calculate the overall average effect size of influencing factors of technology transfer performance. As the result, the overall effect size (ESr) calculated through meta-analysis applying random effect model is .269, which corresponds to the medium effect size. By comparing effect sizes of influencing factors, the four(4) key influencing factors were also identified, which are 'number of researchers', 'dedicated organization', 'possess technology', and 'external cooperation'. The technology transfer performance are divided into three types: the number of technology transfers, technology transfer income, and other technology transfer performances. The major influencing factors of each type are derived through meta-analysis at the sub-category level. As moderator variables, the paper type and the data type were analyzed but no significant results were obtained. Since this research is limited to the technology transfer, it is necessary to carry out the study related to the influencing factors on the technology commercialization as following study.

• Journal of the Korean Data and Information Science Society
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• v.23 no.2
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• pp.317-331
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• 2012

The purpose of this study was to verify the relationship among servant leadership, empowerment and sports satisfaction of badminton coaches by self-leadership. Among national badminton players, total 343 copies of data were collected and used at the study by using of random sampling. The normal distribution on data and the validity and reliability for each factors were proven to confirm through descriptive statistics, exploratory & confirmatory factor analysis and reliability analysis with SPSS 18.0 and AMOS 18.0 program. The relationship among each factors by the purpose of study were analyzed by correlation analysis and structural model analysis. The results were as follows. First, the servant leadership of badminton coaches had positive effect on empowerment. Second, the servant leadership of badminton coaches had positive effect on self-leadership. Third, the servant leadership of badminton coaches had positive effect on sports satisfaction. Fourth, empowerment had positive effect on sports satisfaction. Fifth, self-leadership had positive effect on sports satisfaction. Sixth, for the relationship between servant leadership and sports satisfaction, empowerment and self-leadership had indirect effects.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5777-5783
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• 2012

Published data on the associations between tumor necrosis factor-alpha (TNF-${\alpha}$) promoter -308G>A and -238G>A polymorphisms and cervical cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Data were collected from MEDLINE and PubMed databases. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were calculated in a fixed/random effect model. 13 separate studies including 3294 cases and 3468 controls were involved in the meta-analysis. We found no association between TNF-${\alpha}$-308G>A polymorphism and cervical cancer in overall population. In subgroup analysis, significantly elevated risks were found in Caucasian population (A vs. G: OR = 1.43, 95% CI = 1.00-2.03; AA vs. GG: OR = 2.09, 95% CI = 1.34-3.25; Recessive model: OR = 2.09, 95% CI = 1.35-3.25) and African population (GA vs. GG: OR = 1.53, 95% CI = 1.02-2.30). An association of TNF-${\alpha}$-238G>A polymorphism with cervical cancer was found (A vs. G: OR = 0.61, 95% CI = 0.47-0.78; GA vs. GG: OR = 0.59, 95% CI = 0.45-0.77; Dominant model: OR = 0.59, 95% CI = 0.46-0.77). When stratified by ethnicity, similar association was observed in Caucasian population (A vs. G: OR = 0.62, 95% CI = 0.46-0.84; GA vs. GG: OR = 0.59, 95% CI = 0.43-0.82; Dominant model: OR = 0.60, 95% CI = 0.44-0.83). In summary, this meta-analysis suggests that TNF-${\alpha}$-238A allele significantly decreased the cervical cancer risk, and the TNF-${\alpha}$-308G>A polymorphism is associated with the susceptibility to cervical cancer in Caucasian and African population.

• Journal of Bio-Environment Control
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• v.8 no.3
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• pp.192-201
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• 1999

This study was aimed to introduce the measurement of $CO_2$ concentration and leaf area index in the phytotron for predicting the effect of CO.E, light and leaf area index on the instantaneous photosynthetic rate of sweet pepper with the existing ASKAM model. Measurements were made in 2 semi-closed phytotron compartments in which three different $CO_2$ concentrations were applied at random. Plants were grown on containers with circulating nutrient solution at 21$^{\circ}C$ and 80-95% relative humidity. The model estimates crop net $CO_2$ uptake for short time intervals during the day based on short-term data of daily radiation, temperature and $CO_2$ concentration. During the photosynthesis measurements, $CO_2$ concentrations in both compartments and in the basement were measured every minute. This was also done for the flow of pure $CO_2$ into the compartment, global radiation, photosynthetic active radiation inside the compartment, temperature and relative humidity. Crop growth models summarize our knowledge on crop behavior and have as such a wide range of applications in analysis, crop management and thus as a farm management tool.

• International Area Studies Review
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• v.12 no.3
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• pp.321-339
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• 2008

The purpose of this study to the analyze characteristics and purchasing activities of consumers by using the Multinomial Logit model, which is a well-known discrete selection model to explain and forecast consumers' selection activities(patterns). The study aims to determine the state of competition between National Brand and Private Band and how some demographic characters and marketing variables influence consumers' brand selections within the facial tissue market. Our analysis process includes reorganization of panel data(individuals' purchasing record at each point) to fit the purpose of our study as well as analysis of probability and influencing factors of consumers' brand selection at each point of purchases. The result showed that consumers at higher age and with higher income hold better probability to purchase National Brand. Likewise, locations also had considerable effect on selecting brand, and Private Brand was preferred in department store and discount stores. On the other hand, consumers loyal to National Brand reported higher probability to purchase if the product prices were higher while Private Brand buyers were more promoted the purchase under price discount.