• Journal of the Korean Data and Information Science Society
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• v.27 no.2
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• pp.363-372
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• 2016

Two-stage sample designs are commonly used for household surveys in Korea using as clusters the enumeration districts (EDs). Since clustering decomposes the population variation into within- and between-cluster variations, the sample sizes allocated in stages can affect the overall precision. Alternative clusters are often considered due to diverse reasons such as the EDs' limitation in size, being out-of-date, and in-assessibility to their household lists. In addition, the EDs are currently under development by the Statistics Korea as an joint effort toward their transition from the traditional practice to the register census from 2015. We present an approach for evaluating the difference in the precision of the mean estimators of the sets of the cluster units in between a hierachical and nested form, where the design effect is used to reflect the effect of the clustering and the sample allocation. We also demonstrate our approach using the U.S. Census counts from the year 2000 for Anne Arundel County in Maryland. Our research shows that the within-cluster variance can be significantly different for survey variables and thus the choice of cluster units and the associated sample allocation scheme should reflect the corresponding variance decomposition due to clustering.

• Journal of Korea Water Resources Association
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• v.43 no.10
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• pp.893-909
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• 2010

The purpose of this study is to consider the interaction between surface water and groundwater in basin scale by developing TANK_GS model. The soil moisture structure of tank model with 3 tanks is improved to simulate the appropriate stream-aquifer interactions. Maximum likelihood method is applied to calibrate parameters with variance functions to deal with heteroscedasticity of residuals. The parameters of improved TANK_GS model and variance function are simultaneously estimated by Simulated Annealing method, a global optimization technique. The results of TANK-GE are compared to those of the SWMM-GE model which had been developed to consider the stream-aquifer interactions. The new TANK_GS model and SWMM-GE model are applied to Gapcheon basin, which belongs to Geum River basin. TANK_GS model showed better model performance compared to the original TANK model and characterized the relationship of stream-aquifer interactions as satisfactorily as the SWMM-GE model. The sustainable groundwater yield can be estimated for the regional water resources planning using the TANK_GS model

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.9 no.1
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• pp.3-12
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• 1998

The present study compared the self report and parental report on the behavior problems of adolescents as a way to explore similarities and differences in the ways that adolescents and their parents conceptualize behavior problems of adolescents. Specifically, K-CBCL and YSR data from 3271 adolescents between the ages of 12 and 17 were subjected to factor analyses. Five factors；Depression/Anxiety/Withdrawal, Aggressiveness, Somatic Symptom, Disruptiveness, Attention Getting were obtained from the YSR data with the first factor, Depression/Anxiety/Withdrawal explaining 14.23% of the total variance. K-CBCL data yielded somewhat different factor structure with Aggression/Delinquency as the first factor explaining 14.08% of the total variance, followed by Somatic Symptoms, Social Withdrawal, Disruptiveness, and Depression/Anxiety. Total K-CBCL and YSR score showed a moderate correlation(r=.51), and correlation between pairs of comparable K-CBCL and YSR factor scores were also moderate. Regression analyses of the variables contributing to the total problem score of the K-CBCL and YSR suggested that social competence and academic achievement are two important sources of influence on the evaluation of behavior problems both in self-report and parental report. However, externalizing problems such as aggressiveness/delinquency appeared to be more salient for parents, while adolescents themselves appeared to be more concerned with internalizing problems such as depression/anxiety. Implications of these subtle differences for assessment of adolescent behavior problems were discussed.

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.470-478
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• 2011

Aster altaicus var. uchiyamae is on the list of endangered species in Korea. Using amplified fragment length polymorphism (AFLP) markers, we investigated the genetic diversity within and among four populations (Guram, Dori Island, Samhap, and Danyang) of A. altaicus var. uchiyamae. We also present the collecting strategies that most efficiently capture the genetic diversity of A. altaicus var. uchiyamae. Four AFLP primer combinations produced a total of 936 bands, of which 934 (99.8%) were polymorphic. A high level of genetic diversity (PPB = 45.3%, h = 0.104, I = 0.168, hs = 0.108) was recognized within the populations of A. altaicus var. uchiyamae. A low degree of genetic differentiation ($G_{ST}$ = 0.075, ${\theta}^B$ = 0.079) was detected among the populations. In addition, analysis of molecular variance (AMOVA) showed that genetic variation was greater within populations (91%) than among populations (9%). These results indicate that the high rate of gene flow has played an important role in forming the present populations of A. altaicus var. uchiyamae. According to maximization strategy, 17, 16, and 11 individuals captured all of the genetic variation in Dori Island, Samhap, and Guram population, respectively. The determination the minimum population size of A. altaicus var. uchiyamae in terms of the genetic information is critical and thereby gain reliable decision support for ex situ conservation of the endangered species, A. altaicus var. uchiyamae.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.2
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• pp.94-110
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• 2003

This study utilizes the dataset of Topex/Poseidon(T/P) altimeter sea surface height (1992-2000 yr., 286 cycles)to investigate the tempore-spatial variability in the East (Japan) Sea. Optimal interpolation (Ol) technique was applied to the pre-processed T/P dataset (level 2) to produce sea surface height anomaly (SSHA) map on regular grids. Spectral analyses of the timeseries of the SSHA at chosen stations and empirical orthogonal function (EOF) analysis of the SSHA in the entire East Sea were made. Distribution of the SSHA can be divided by the southern and northern regions sharply by the polar front situated in the middle of the East Sea. The southern region under the direct influence of the Tsushima Current exhibits higher amplitude of the SSHA fluctuation, while the northern region does relatively smaller one. The spatio-temporal variability of the SSHA in the East Sea can be characterized by the five modes of the EOFs accounting for more than 85% of the total variance. The first mode dominates the SSHA variation in the entire domain with strong seasonal and inter-annual periods accounting for the 72.3% of the total variance. The other modes (up to 5th account for 14%) are responsible for the SSHA variation associated with the local current system, meandering of the polar frontal axis, and mesoscale eddies. Spectral peaks with significant confluence level show semi-annual, annual and interannual (2, 3-4 years) periods.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.4
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• pp.30-40
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• 1997

The change in health care environment increases the importance of Visiting Nursing Services Program. It has been performed by nurses of district health centers in Seoul since 1991. The Achievement of Visiting Nursing Services Program will be dependent upon their activities. The purpose of this study was to identify the Performance of Visiting Nurses and Job satisfaction of district health centers in Seoul. Therefore, it was to provide the fundamental data development of Visiting Nursing Services Program. The subjects were 214 Visiting Nurses of district health centers in Seoul. The data was collected by self reporting questionnaire from April 15 to April 30, 1997. Their performances and various supportive factors were measured with the instruments developed by the researcher. Job satisfaction were also measured by the instrument developed by Slavitt et al. (1978) was used. The data were, analyzed by Cronbach Alpha, mean, standard deviation, percentage, t -test, ANOVA Duncan test, Correlation Coefficient, and Stepwise Multiple Regression with SAS program. The results of this study were as follows: 1. The average of budget of Visiting Nursing Services Program of district health centers was 0.9% and the average of visiting nursing services personnel of district health centers was 10.1%. 2. With regard to the job satisfaction of Visiting Nurses the mean score was 2.92 out of 5. While the level of Job prestige / status presented as a mean score of 3.48 which was the largest among the 7 components of job satisfaction, the level of administration was the lowest showing 2.57 scores respectively. There were significant differences in the job satisfaction by age, working career of health centers(p<0.01, 0.001). 3. The average of the performance level of Visiting Nurses variables was 2.29; The variable with highest degree of performance was the teaching & consultation, establishment of performance plan, whereas the on with the lowest degree was the directive nursing services. The significant difference was found in performance level according to age, structure type of visiting nursing services, working career of health centers and working career of visiting nursing services(p<0.05). 4. With regard to the perception of the performance expertise by the Visiting Nurses the mean score was 2.37 : The variable with highest degree of performance expertise was the teaching & consultation, establishment of performance plan, whereas the on with the lowest degree was management of home-environment. The significant difference was found in performance expertise according to working career outside of health centers(p<0.05). 5. With regard to the perception of the performance necessity by the Visiting Nurses the mean was 2. 40 : the variable with highest degree of performance necessity was the teaching & consultation, establishment of performance plan, whereas the on with the lowest degree was directive nursing services. The significant difference was found in performance necessity according to working career of visiting nursing services(p<0.05). 6. A positive correlation was found between job satisfaction and performance level(r=.3731, P<0.001). Also, a weak positive correlation was found between the components of job satisfaction and performance level. 7. Stepwise multiple regression analysis revealed that the most powerful predictor was the variance of job satisfaction(R=.3557, $R^2$=.1265). Structure type of visiting nursing services and working career of visiting nursing services accounted for 19.0% of the variance in performance level in nurses. In conclusion, Job satisfaction, Structure type of visiting nursing services and Working career of visiting nursing services variables had influenced on performance level in health centers. Further research is required to confirm these findings.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.6
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• pp.902-912
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• 2020

Objective: Mongolia is one of a few countries that supports over 25 million goats, but genetic diversity, demographic history, and the origin of goat populations in Mongolia have not been well studied. This study was conducted to assess the genetic diversity, phylogenetic status and population structure of Mongolian native goats, as well as to discuss their origin together with other foreign breeds from different countries using hypervariable region 1 (HV1) in mtDNA. Methods: In this study, we examined the genetic diversity and phylogenetic status of Mongolian native goat populations using a 452 base-pair long fragment of HVI of mitochondrial DNA from 174 individuals representing 12 populations. In addition, 329 previously published reference sequences from different regions were included in our phylogenetic analyses. Results: Investigated native Mongolian goats displayed relatively high genetic diversities. After sequencing, we found a total of 109 polymorphic sites that defined 137 haplotypes among investigated populations. Of these, haplotype and nucleotide diversities of Mongolian goats were calculated as 0.997±0.001 and 0.0283±0.002, respectively. These haplotypes clearly clustered into four haplogroups (A, B, C, and D), with the predominance of haplogroup A (90.8%). Estimates of pairwise differences (Fst) and the analysis of molecular variance values among goat populations in Mongolia showed low genetic differentiation and weak geographical structure. In addition, Kazakh, Chinese (from Huanghuai and Leizhou), and Arabian (Turkish and Baladi breeds) goats had smaller genetic differentiation compared to Mongolian goats. Conclusion: In summary, we report novel information regarding genetic diversity, population structure, and origin of Mongolian goats. The findings obtained from this study reveal that abundant haplogroups (A to D) occur in goat populations in Mongolia, with high levels of haplotype and nucleotide diversity.

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.567-575
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• 2001

In order to consider statistical properties of probability variables used in the structural analysis the conventional approach using the safety factor based on past experience usually estimated the safety of a structure Also the real structures could only be analyzed with the error in estimation of loads material characters and the dimensions of the members. But the errors should be considered systematically in the structural analysis Safety of structure could not precisely be appraised by the traditional structural design concept Recently new aproach based on the probability concept has been applied to the assessment of structural safety using the reliability concept Thus the computer program by the Probabilitstic FEM is developed by incorporating the probabilistic concept into the conventional FEM method. This paper estimated for the reliability of a plane stress structure by Advanced First-Order Second Moment method using von Mises, Tresca and Mohr-Coulomb failure criterions. Verification of the reliability index and failure probability of attained by the Monte Carlo Simulation method with the von Mises criterion were same as PFEM, but the Monte Carlo Simulation were very time-consuming. The variance of member thickness and load could influence the reliability and failure probability most sensitively among the design variables from the results of the parameter analysis. The proper failure criterion according to characteristic of materials must be used for safe design.

• The Journal of Korean Academy of Prosthodontics
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• v.46 no.3
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• pp.307-319
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• 2008

STATEMENT OF PROBLEM: It is known that an anodic oxidation technique, one of the methods for the implant surface treatment, remarkably increased surface area, enhanced wettability and accelerated the initial bone healing. Purpose: This study was performed to evaluate the wettability of anodized titanium surface which has a nanotubular structure, to assess osseointegration after the placement of implant with nano-size tubes on tibia of rats and to analyze quantitatively transferable rhBMP-2 on each surface. MATERIAL AND METHOD: Four different kinds of surface-treated titanium discs (polished (machined surface) group, micro (blasting surface) group, nano (anodizedmachined surface) group, and nano-micro (anodized-blasting surface) group) were fabricated (n=10). Three different media were chosen to measure the surface contact angles; distilled water, plasma and rhBMP-2 solution. After a single drop (0.025 $m{\ell}$) of solution, the picture was taken with the image camera, and contact angle was measured by using image analysis system. For the test of osseointegration, 2 kinds of anodized surface (anodized-machined surface, anodized-blasting surface) implants having 2.0 mm in diameter and 5.0 mm in length inserted into the tibia of Wistar rats. After 3 weeks, tibia were harvested and the specimens were stained with hematoxylin and eosin for histological analysis. To test the possibility of drug delivery, after soaking sample groups in the concentration of 250 ng/$m{\ell}$l of rhBMP-2 for 48 hours, the excess solution of rhBMP-2 were removed. After that, they were lyophilized for 24 hours, and then the rhBMP-2 on the surface of titanium was resolved for 72 hours in PBS. All the extracted solution was analyzed by ELISA. One-way analysis of variance (ANOVA) was performed on the data. RESULTS: The wettability is improved by anodic oxidation. The best wettability was shown on the nano-micro group, and it was followed by nano group, micro group, and polished group. In the histological findings, all implants showed good healing and the new bone formation were observed along the implant surface. After 3 days, nano-micro group delivered the most amount of rhBMP-2, followed by nano group, micro group, and polished group. CONCLUSION: It indicated that anodic oxidation on blasting surface produce functionally graded nano-micro porous structure and enhance hydrophilicity of the surface and osseointegration. The findings suggest that the nano-micro porous structure could be a useful carrier of osteogenic molecules like rhBMP-2.

• Korean Journal of Plant Resources
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• v.26 no.5
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• pp.619-627
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• 2013

Deutzia paniculata Nakai is a Korean endemic species that has a very restricted distribution in Gyeongsang-do, South Korea. The genetic diversity and structure of five populations of D. paniculata were investigated using 31 ISSR loci from six primers. The Shannon's index (0.429) and genetic diversity (0.271) were relatively higher than those of other rare plant species in Korea. The Miryang (MY) and Yangsan (YS) populations, which have higher flowering rates than the other populations, showed greater genetic diversity than the other populations. An analysis of the molecular variance (AMOVA) showed that 16% of the total variation could be attributed to differences among the populations, and 84% to the differences within populations, indicating moderate gene flow among adjacent populations. The high genetic diversity and low genetic differentiation in the Deutzia paniculata populations, which have a restricted distribution, is considered to be affected by outcrossing of the mating system and abundant individuals in the populations. These results suggest that ex situ conservation strategies are needed to sustain the current genetic diversity of D. paniculata.