• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.531-538
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• 2009

We used enzyme electrophoresis to evaluate genetic diversity in five populations of endemic ash, Fraxinus chiisanensis in Korea. Of 15 putative allozyme loci examined 26.7% were polymorphic and expected heterozygosity for the species was low (0.082). Within the range, population were highly differentiated ($F_{ST}$=0.356) and little genetic variation was explained by geography. The pattern of distribution of variation showed low genetic variation within populations and pronounced divergence among populations, which was consistent with the prediction for the effects of limited gene flow and local genetic erosion. Although the frequencies of male plants were dominant ranging from 79.3% to 89.4%, most mating events seems to be inevitable mating between relatives in small populations based on heterozygote deficiency of this species. Small effective population size and the limited dispersal contributed to the low rates of gene flow within as well as between populations.

• Korean Journal of Poultry Science
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• v.44 no.2
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• pp.83-92
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• 2017

The purpose of this study was to estimate the inbreeding level and effective population size of Korean indigenous chickens. In the study, two variables were considered to evaluate the pedigree completeness: (1) the proportion (%) of animals with complete pedigree, and (2) the proportion of animals with inbreeding coefficients greater than zero. In the proportion of animals having complete pedigree, all strains reached almost 100% completeness in 1~2 years. In the proportion of animals with inbreeding coefficients greater than zero, all strains reached almost 100% completeness in 5~6 years. We considered that the pedigree recoding system is well managed and that the inbreeding coefficient is a reliable measure. Over the past 20 years, the increase of inbreeding coefficients in Korean indigenous chicken strains has been 7.6~10.9%. The S strain showed the most rapid increase of inbreeding coefficient of 8.2% in 10 years. The reason for this rapid increase is considered to be associated with the fact that the numbers of sires and dams involved in reproduction was 115 and 91, respectively, which are lower than those of the other strains. According to average rates of increase in inbreeding coefficients (${\Delta}F$), all strains have ${\Delta}F$ values of 0.39~0.85%, which is lower than 1%, and the effective population size is above 50. The results showed that inbreeding levels were within the acceptable range and that Korean indigenous chicken population scan be regarded as safe from the threat of extinction.

• Biomaterials and Biomechanics in Bioengineering
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• v.1 no.2
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• pp.95-104
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• 2014

The objective of this study was to evaluate the cytotoxicity of poly (lactic acid) (PLA) nanoparticles. We used a water-soluble, amphiphilic phospholipid polymer, poly (2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB30W), as a stabilizer for the PLA nanoparticles. The PLA nanoparticles and PMB30W-modified PLA (PLA/PMB30W) nanoparticles were prepared by evaporating tetrahydrofuran (THF) from its aqueous solution. Precipitation of the polymers from the aqueous solution produced PLA and PLA/PMB30W nanoparticles with a size distribution of $0.4-0.5{\mu}m$. The partial coverage of PMB30W on the surface of the PLA/PMB30W nanoparticles was confirmed by X-ray photoelectron spectroscopy (XPS) and dynamic light-scattering (DLS). A high-content automated screening assay (240 random fields per group) revealed that the PLA nanoparticles induced apoptosis in a mouse macrophage-like cell line (apoptotic population: 73.9% in 0.8 mg PLA/mL), while the PLA/PMB30W nanoparticles remained relatively non-hazardous in vitro (apoptotic population: 13.8% in 0.8 mg PLA/mL). The reduction of the apoptotic population was attributed to the phosphorylcholine groups in the PMB30W bound to the surface of the nanoparticle. In conclusion, precipitation of PLA in THF aqueous solution enabled the preparation of PLA nanoparticles with similar shapes and size distribution but different surface characteristics. PMB30W was an effective stabilizer and surface modifier, which reduced the cytotoxicity of PLA nanoparticles by enabling their avoidance of the mononuclear phagocyte system.

• Communications for Statistical Applications and Methods
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• v.20 no.2
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• pp.97-105
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• 2013

Stratification (among other applications) is a popular technique used in survey practice to improve the accuracy of estimators. Its full potential benefit can be gained by the effective use of auxiliary variables in stratification related to survey variables. This paper focuses on the problem of stratum formation when multiple stratification variables are available. We first review a variance reduction strategy in the case of univariate stratification. We then discuss its use for multivariate situations in convenient and efficient ways using three methods: compromised measures of size, principal components analysis and a K-means clustering algorithm. We also consider three types of compromising factors to data when using these three methods. Finally, we compare their efficiency using data from MU281 Swedish municipality population.

• ETRI Journal
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• v.23 no.3
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• pp.129-137
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• 2001

A random sampling or systematic sampling method is commonly used to assess the accuracy of classification results. In remote sensing, with these sampling methods, much time and tedious work are required to acquire sufficient ground truth data. So, a more effective sampling method that can represent the characteristics of the population is required. In this study, fractal analysis is adopted as an index for reference sampling. The fractal dimensions of the whole study area and the sub-regions are calculated to select sub-regions that have the most similar dimensionality to that of the whole area. Then the whole area's classification accuracy is compared with those of sub-regions, and it is verified that the accuracies of selected sub-regions are similar to that of whole area. A new kind of reference sampling method using the above procedure is proposed. The results show that it is possible to reduce sampling area and sample size, while keeping the same level of accuracy as the existing methods.

• Genomics & Informatics
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• v.10 no.2
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• pp.117-122
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• 2012

A sample size with sufficient statistical power is critical to the success of genetic association studies to detect causal genes of human complex diseases. Genome-wide association studies require much larger sample sizes to achieve an adequate statistical power. We estimated the statistical power with increasing numbers of markers analyzed and compared the sample sizes that were required in case-control studies and case-parent studies. We computed the effective sample size and statistical power using Genetic Power Calculator. An analysis using a larger number of markers requires a larger sample size. Testing a single-nucleotide polymorphism (SNP) marker requires 248 cases, while testing 500,000 SNPs and 1 million markers requires 1,206 cases and 1,255 cases, respectively, under the assumption of an odds ratio of 2, 5% disease prevalence, 5% minor allele frequency, complete linkage disequilibrium (LD), 1:1 case/control ratio, and a 5% error rate in an allelic test. Under a dominant model, a smaller sample size is required to achieve 80% power than other genetic models. We found that a much lower sample size was required with a strong effect size, common SNP, and increased LD. In addition, studying a common disease in a case-control study of a 1:4 case-control ratio is one way to achieve higher statistical power. We also found that case-parent studies require more samples than case-control studies. Although we have not covered all plausible cases in study design, the estimates of sample size and statistical power computed under various assumptions in this study may be useful to determine the sample size in designing a population-based genetic association study.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.639-650
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• 2022

Abeliophyllum distichum Nakai, a rare plant with distylous characteristics, is native to certain parts of the Korean Peninsula. It is registered on the IUCN Red List of Threatened Species as a globally endangered plant. This study was conducted to establish an appropriate local conservation management plan suitable for future A. distichum populations by comparing and analyzing the flowering characteristics and population size according to distyly based on the results of quantitative surveys in 14 regions, including 8 areas with native populations of A. distichum and 6 natural monument populations. The number of individuals appearing in each population group was surveyed, and the flowering individuals were identified by style as being either pin or thrum flower types as they were being examined and recorded on the site. In total, 13,130 individuals of A. distichum (7,003 flowering and 6,127 non-flowering individuals) were recorded, but the balance of the number of pin- and thrum-flowered individuals in each population was not significant (p<0.05), indicating an imbalanced state. In particular, the Yeongdong (YD) population was very disproportionate compared to other populations, suggesting that its genetic diversity was low and the possibility of inbreeding was high. The average flowering and fruiting rates by management unit were much higher in the natural monument populations (89.2% and 55.3%, respectively) than in the natural habitat populations (39.0% and 8.5%, respectively). It may be due to a difference in reproductive growth resulting from light inflow into the forest caused by the upper crown closure. The area of occupation (AOO) of A. distichum on the Korean Peninsula covered an area of 23,224.5 m². Although the natural monument population was smaller than the natural habitat population, its density was higher, likely as a result of the periodic management of natural monument populations, where the installation of protective facilities in certain areas restricts population spread. Conservation of A. distichum populations requires removing the natural monument populations suspected of anthropogenic and genetic disturbances and expanding the conservation priority population by designating new protected areas. Although the habitats of natural monument populations are managed by the Cultural Heritage Administration and local governments, there are no agencies that are responsible for managing natural habitat populations. Therefore, institutional improvement in the overall management of A. distichum should be prioritized.

• Journal of Korean Academy of Nursing
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• v.51 no.5
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• pp.597-616
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• 2021

Purpose: This study's objective was to investigate the effects of programs that improve adolescents' body image, using a systematic review and meta-analysis. Methods: A literature search was performed in eleven electronic databases, using preferred reporting items for systematic reviews and meta-analysis guidelines. Population characteristics, contents of the programs, and measured outcomes were systematically reviewed from 21 selected studies. To estimate the size of the effects, meta-analysis was conducted using Comprehensive Meta-Analysis software. Results: The contents of the programs that aimed to improve body image included physical, psychological, interpersonal, and sociocultural interventions. Sixteen studies were meta-analyzed to estimate the effect size of body-image improvement programs. Results showed that the program for body-image improvement had significant effects on body satisfaction (effect size [ES] = 0.56, 95% confidence interval [CI] = 0.23 to 0.89), and body dissatisfaction (ES = - 0.15, 95% CI = - 0.23 to - 0.08). Conclusion: The program for body image improvement in adolescents includes a combination of physical, psychological, interpersonal relationship, and socio-cultural dimensions. The program that seeks to improve body image appears to be effective at increasing body satisfaction, and at reducing body dissatisfaction in adolescents. Thus, it is necessary to develop and apply multidimensional programs for adolescents to have a positive body image.

• Journal of the Korean Society of Clothing and Textiles
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• v.40 no.5
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• pp.954-965
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• 2016

This study was designed to help develop an optimized sizing system for the military winter jackets of Korean males. First, we conducted a survey on the supply rate of military winter jackets and the wearing of suitable size jackets in order to identify problems in the current sizing system. We next developed a new sizing system generation method to satisfy the coverage rate and appropriate size number: Hybrid of Grid with Optimization. The findings of this study were: 1. The survey indicated that a 90 (chest girth) size is necessary; in addition, a one-step large size jacket fit well as a right size jacket. 2. We developed three optimized sizing systems for Korean male military winter jackets using the Hybrid of Grid with an optimization method and suggested one of them as a final new sizing system. The new sizing system consisted of two primary dimension: chest girth and stature. It has a 14 size number and its extended coverage rate is larger than the current sizing system and it has a 90 (chest girth) size. It also selected an optimized size for the area of low population density. The new sizing system is therefore considered very effective for Korean male soldiers military winter jackets.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.105-115
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• 2004

This study was carried out to grade and evaluate the intertidal mudflat by birds. The mudflat was graded by two methods such as the scoring and ranking. First, for the scoring of the mudflat, five factors were estimated; population size, the number of protected species, the individuals of protected birds, the number of species(or subspecies) over 1% level of the survival population, and 1% level of the domestic population. After scoring of these five factors, the grade was scored by total. Second, for the ranking, six factors were estimated; population size, the density of birds, the index of species diversity, species richness, species evenness, and population stability. After ranking of these six factors, the grade was relatively ranked. Five grade by scoring was the important mudflat for the value of international preservation, and the most mudflats of the estuary gained V grade. The higher grades by ranking were the mudflats of Nakdonggang and Mankyunggang river estuaries. And the inner mudflats were more valuable than the outer mudflats in Mankyunggang & Dongjingang river estuaries. The grading of the mudflat by birds can be used for estimating and appointing of the important mudflats, and suggested the objective of criteria for the effective preservation and management.