• Journal of Korean Society on Water Environment
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• v.23 no.4
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• pp.482-489
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• 2007

Fluorescence properties and carbohydrate content were investigated using ultrafiltrated size fractions of dissolved organic matters (DOM) originated from different sources. The materials included a treated sewage, an algal organic matter, and a soil leachate, all of which are major constituents of dissolved organic matter in a typical urban river. Four different size fractions were separated from the three sources of each DOM. The size distribution demonstrated that a higher molecular weight fraction was more present in soil leachate compared to two other source DOMs. A higher content of carbohydrates was observed in the following order - algal DOM > treated sewage > soil leachate. A wide range of specific UV absorbance was observed from size fractions of a single source DOM, indicating that aromatic carbon structures are heterogeneously distributed within one source of DOM. The structural heterogeneity was the most pronounced for the soil leachate. The fluorescence index ($F_{450}/F_{500}$) of the treated sewage was similar to that (2.0) typically obtained from autochthonous DOM, suggesting that the treated sewage exhibited autochthonous organic matter-like properties. No protein-like fluorescence intensities were observed for all of the soil leachate size fractions whereas they were observed with two other source DOMs. Based upon the fluorescence peak ratios from fluorescence excitation-emission matrix (EEM), two discrimination indices could be suggested to distinguish three different source DOMs. It is expected that the suggested discrimination indices will be useful to predict the sources of DOM in a typical urban river affected by treated sewage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.271-284
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• 2016

This study was carried out to evaluate the efficacy of CBT for perinatal depression through systematic literature review and meta-analysis. The following databases were used to search the literature: CINAHL, PubMed, EMBASE, Koreamed, Library of Korean Congress, KISS, and Korean Academic Publication Database. Keywords included 'perinatal depression,' 'pregnant women,' and 'cognitive behavioral therapy,' and the evaluated articles were published up to May 2016. Using the R program, the effect size of perinatal depression and anxiety were calculated by random-effects model. The heterogeneity of the effect size was analyzed by data moderator analysis using the meta-ANOVA. Furthermore, the funnel plot, Egger's regression test, fail-safe N, trim-and-fill test, and publication bias analysis were conducted and used to verify the results. Out of the 180 selected articles, 16 clinical trial studies were meta-analyzed. Each articles were evaluated for the risk of bias by the checklist of SIGN; the overall risk of bias was low. The effect size of CBT for perinatal depression was Hedges' g=-0.55 (95% CI: -0.76~-0.33), which was a moderate level, while for anxiety reduction, Hedges' g=-0.20 (95% CI: -0.48~-0.08) and it was not statistically significant. Heterogeneity or risk of publication bias were low. This meta-analytic study found that CBT is moderately effective in reducing perinatal depression in pregnant women.

• 한국노년학
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• v.37 no.2
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• pp.431-444
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• 2017

This study identified effect size of cognition improvement programs developed for normal elderly in Korea. By searching four databases, 9,624 studies published from 2000 to 2016 were identified. Finally, 14 studies which satisfied the inclusion criteria were selected for meta-analysis. Quality assessment of included studies was conducted using controlled trial checklist of Scottish Intercollegiate Guidelines Network. R version 3.3.2 (2016-10-31) with "meta" and "metafor" package was used to calculate effect sizes, identify the reasons of heterogeneity, and check publication bias. Total effect size of cognition improvement program was middle (SMD=0.759, p<.001, $I^2=34%$). For heterogeneity, moderator analysis was executed and combined program with exercise had the largest effect size (SMD=1.231, p<.001, $I^2=40.8%$). Publication bias was exist by funnel plot and Egger 's regression test, but trim and fill analysis showed that there was no serious error to reverse study results. Therefore, Combined program with exercise for the normal elderly was expected to improve the cognitive function of the normal elderly.

• The Journal of the Korea Contents Association
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• v.14 no.3
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• pp.203-214
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• 2014

In this study, a meta-analysis was conducted to investigate the effect of community-based rehabilitation on patients with brain injury by ICF factor in previous studies and examine the application of recent community-based rehabilitation program. Total 15 articles that satisfied the selection criteria were divided by ICF factors to obtain the effect size. Homogeneity and publication bias were tested for those selected papers. As a result, the overall effect size of community-based rehabilitation was 0.22; the effect size by physical function and structure among the ICF factors came to be 0.21; and the effect size of activity and participation was 0.20, indicating a small effect size. The studies involved in a meta-analysis were considered as the absence of heterogeneity and publication bias, which indicates that the results of this study are subjectively reliable. These results well explained the level of change on ICF factors, especially physical function and structure, activity and participation, in other words, the intervention effect of community-based rehabilitation on patients with brain injury.

• The Journal of Engineering Geology
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• v.27 no.4
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• pp.463-474
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• 2017

Heterogeneous background fractures of granite and sedimentary rocks in Gyeongju LILW (low-intermediate level radioactive waste) facility area have been characterized quantitatively by analyzing fracture parameters (orientation, intensity, and size). Surface geological survey, electrical resistivity survey, and acoustic televiewer log data were used to characterize the heterogeneity of background fractures. Bootstrap method was applied to represent spatial anisotropy of variably oriented background fractures in the study area. As a result, the fracture intensity was correlated to the inverse distance from the faults weighted by nearest fault size and the mean value of electrical resistivity and the average volumetric fracture intensity ($P_{32}$) was estimated as $3.1m^2/m^3$. Size (or equivalent radius) of the background fractures ranged from 1.5 m to 86 m and followed to power-law distribution based on the fractal property of fracture size, using fractures measured on underground silos and identified surface faults.

• Journal of Ecology and Environment
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• v.44 no.4
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• pp.229-240
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• 2020

Background: Genus Quercus is a successful group that has occupied the largest area of forest around the world including South Korea. The acorns are an important food source for both wild animals and humans. Although the reproductive characteristics of this genus are highly variable, it had been rarely studied in South Korea. Therefore, in Seoraksan and Odaesan National Parks (i) we measured the acorn production of Quercus mongolica, an overwhelmingly dominant species in South Korea, for 3 years (2017-2019), (ii) evaluated the spatial-temporal variation of acorn production, and (iii) analyzed the effects of oak- and site-related variables on the acorn production. Results: The annual acorn production of Q. mongolica increased 36 times from 1.2 g m-2 in 2017 to 43.2 g m-2 in 2018, and decreased to 16.7 g m-2 in 2019, resulting in an annual coefficient of variation of 104%. The coefficient of spatial variation was high and reached a maximum of 142%, and the tree size was the greatest influencing factor. That is, with an increase in tree size, acorn production increased significantly (2018 F = 16.3, p < 0.001; 2019 F = 8.2, p < 0.01). Elevation and slope also significantly affected the production in 2019. However, since elevation and tree size showed a positive correlation (r = 0.517, p < 0.001), the increase in acorn production with increasing elevation was possibly due to the effect of tree size. The acorn production of Odaesan for 3 years was 2.2 times greater than that of Seoraksan. This was presumed that there are more distribution of thick oak trees and more favorable site conditions such as deep soil A-layer depth, high organic matter, and slower slopes. Conclusion: As reported for other species of the genus Quercus, the acorn production of Q. mongolica showed large spatial and annual variations. The temporal variability was presumed to be a weather-influenced masting, while the spatial variability was mainly caused by oak tree size.

• Journal of the Economic Geographical Society of Korea
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• v.25 no.4
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• pp.629-640
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• 2022

This study analyzed the relationship between local government size and regional economic growth using regional data from 2002 to 2020. By dividing local government expenditure into social development expenditure and economic development expenditure, economic growth and the inverted U-shaped Armey curve were verified, and the optimal size of local government expenditure was examined. In particular, the AMG estimation method considering the cross-sectional dependence and regional heterogeneity existing in the panel data was utilized. As a result of the analysis, it was found that there was an inverted U-shaped relationship between local fiscal expenditure and regional economic growth. When the proportion of total local fiscal expenditure is 7.63% of GRDP and social development expenditure is 3.45%, it is found that the optimal size of expenditure can maximize the regional economic growth rate. Local governments should increase the effectiveness of public expenditure policies by considering these points.

• Computers and Concrete
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• v.22 no.1
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• pp.53-62
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• 2018

Cracking of concrete cover induced by reinforcement corrosion is a critical issue for life-cycle design and maintenance of reinforced concrete structures. However, the critical degree of corrosion, based on when the concrete surface cracks, is usually hard to predict accurately due to the heterogeneity inherent in concrete. To investigate the influence of concrete heterogeneity, a modified rigid-body-spring model, which could generate concrete sections with randomly distributed coarse aggregates, has been developed to study the corrosion-induced cracking process of the concrete cover and the corresponding critical degree of corrosion. In this model, concrete is assumed to be a three-phase composite composed of coarse aggregate, mortar and an interfacial transition zone (ITZ), and the uniform corrosion of a steel bar is simulated by applying uniform radial displacement. Once the relationship between radial displacement and degree of corrosion is derived, the critical degree of corrosion can be obtained. The mesoscale model demonstrated its validity as it predicted the critical degree of corrosion and cracking patterns in good agreement with analytical solutions and experimental results. The model demonstrates how the random distribution of coarse aggregate results in a variation of critical degrees of corrosion, which follows a normal distribution. A parametric study was conducted, which indicates that both the mean and variation of critical degree of corrosion increased with the increase of concrete cover thickness, coarse aggregates volume fraction and decrease of coarse aggregate size. In addition, as tensile strength of concrete increased, the average critical degree of corrosion increased while its variation almost remained unchanged.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.11
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• pp.1781-1794
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• 2018

Objective: This meta-analysis was conducted to evaluate the overall effect of direct-fed microbial (DFM) or probiotic supplementation on the log concentrations of culturable gut microbiota in broiler chickens. Methods: Relevant studies were collected from PubMed, SCOPUS, Poultry Science Journal, and Google Scholar. The studies included controlled trials using DFM supplementation in broiler chickens and reporting log concentrations of the culturable gut microbiota. The overall effect of DFM supplementation was determined using standardized mean difference (SMD) with a random-effects model. Subgroups were analyzed to identify pre-specified characteristics possibly associated with the heterogeneity of the results. Risk of bias and publication bias were assessed. Results: Eighteen taxa of the culturable gut microbiota were identified from 42 studies. The overall effect of DFM supplementation on the log concentrations of all 18 taxa did not differ significantly from the controls (SMD = -0.06, 95% confidence interval [-0.16, 0.04], p = 0.228, $I^2=85%$, n = 699 comparisons), but the 18 taxa could be further classified into three categories by the direction of the effect size: taxa whose log concentrations did not differ significantly from the controls (category 1), taxa whose log concentrations increased significantly with DFM supplementation (category 2), and taxa whose log concentrations decreased significantly with DFM supplementation (category 3). Category 1 comprised nine taxa, including total bacterial counts. Category 2 comprised four taxa: Bacillus, Bifidobacterium, Clostridium butyricum, and Lactobacillus. Category 3 comprised five taxa: Clostridium perfringens, coliforms, Escherichia coli, Enterococcus, and Salmonella. Some characteristics identified by the subgroup analysis were associated with result heterogeneity. Most studies, however, were present with unclear risk of bias. Publication bias was also identified. Conclusion: DFM supplementation increased the concentrations of some beneficial bacteria (e.g. Bifidobacterium and Lactobacillus) and decreased those of some detrimental bacteria (e.g. Clostridium perfringens and Salmonella) in the guts of broiler chickens.

• Clinical and Experimental Pediatrics
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• v.63 no.2
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• pp.34-43
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• 2020

Phenylketonuria is a disease caused by congenital defects in phenylalanine metabolism that leads to irreversible nerve cell damage. However, its detection in the early days of life can reduce its severity. Thus, many countries have started disease screening programs for neonates. The present study aimed to determine the worldwide prevalence of classic phenylketonuria using the data of neonatal screening studies.The PubMed, Web of Sciences, Sciences Direct, ProQuest, and Scopus databases were searched for related articles. Article quality was evaluated using the Joanna Briggs Institute Critical Appraisal Evaluation Checklist. A random effect was used to calculate the pooled prevalence, and a phenylketonuria prevalence per 100,000 neonates was reported. A total of 53 studies with 119,152,905 participants conducted in 1964-2017 were included in this systematic review. The highest prevalence (38.13) was reported in Turkey, while the lowest (0.3) in Thailand. A total of 46 studies were entered into the meta-analysis for pooled prevalence estimation. The overall worldwide prevalence of the disease is 6.002 per 100,000 neonates (95% confidence interval, 5.07-6.93). The meta-regression test showed high heterogeneity in the worldwide disease prevalence (I²=99%). Heterogeneity in the worldwide prevalence of phenylketonuria is high, possibly due to differences in factors affecting the disease, such as consanguineous marriages and genetic reserves in different countries, study performance, diagnostic tests, cutoff points, and sample size.