• Journal of the Korean Society of Radiology
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• v.17 no.5
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• pp.791-800
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• 2023

This study was conducted to lay the foundation for creating a society safe from radiation by investigating the establishment of a radiation social safety net and the establishment of safety awareness and safety culture among citizens living in Busan. Data was collected through an online survey, and 200 copies of the survey were analyzed. Data were analyzed using SPSS Window Ver 28.0. To verify differences between groups, t-test and one way ANOVA were performed, and correlation analysis was performed to confirm the relationship between variables. In addition, multiple linear regression analysis was conducted to confirm the influence between variables. As a result, first, in terms of building a social safety net, citizens' safety awareness, and establishing a safety culture, the scores of the group with male gender, age in 20s, and high school graduation were found to be high. Among them, there was a statistical difference in gender at the significance level of .01 for building a social safety network and at the significance level of .05 for establishing a safety culture. In terms of occupation, there was a statistical difference between professionals and service workers at the significance level of .05 regarding the building of a radiation social safety network. Second, as a result of multiple regression analysis, it was found that 'local government radiation safety education', a subordinate factor in building a radiation social safety network, had a positive effect on citizens' safety awareness and establishment of a safety culture. Third, the results of the correlation analysis between the building of a social safety network, citizens' safety awareness, and establishment of a safety culture showed a positive correlation. Therefore, it is believed that a good radiation social safety network will have a positive impact on citizens' safety awareness and the establishment of a safety culture.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.167-176
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• 1997

Characteristics of leaf morphology and vegetation were examined in 6 populations of rare endemic tree species, Koelreuteria paniculata Laxm. Additionally we studied genetic variation employing isozyme marker. Nested anova showed that there were statistically significant differences among populations as well as among individuals within populations in all 8 leaf morphological traits. In 7 of 8 traits, variance components among populations were larger than those among individuals within populations. Only a few tree species were found within each population and all the populations seemed to have been disturbed by man. Level of genetic diversity for this rare endemic species was very low, especially compared with those of geographically widespread tree species(A/L=1.1, P=9.5%, $H_o=0.021$, $H_e=0.035$) and degree of genetic differentiation was high($F_{ST}=0.114$). Factors contributing to the low level of genetic diversity and high level of genetic differentiation might include genetic drift, inbreeding and limited gene flow. Finally, implications for the conservation of genetic diversity of Koelreuteria paniculata were discussed.

• Korean Journal of Childcare and Education
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• v.11 no.1
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• pp.501-521
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• 2015

This study aims to examine the effects of the main eight items amended in the 2013 child care center accreditation system and to provide suggestions. The participants in the study were 200 child care center teachers and staff; 150 professionals consisting of public officials in charge of child care, members for the accreditation committee, and inspectors at the site; and 144 parents. They participated in an on-line questionnaire survey conducted during the end of February, 2014. The survey questions regarding the eight changed items were the same to all the three participating groups, and three more questions were asked to child care center teachers and staff. The collected data were analyzed with frequencies and percentages to present general recognition level. For a group comparison, analysis of variance was first performed among 3 professional groups, all of which has the same size. When there was not a statistically significant difference among the three groups, the second analysis of variance was done among three groups of professionals including the three groups, teachers and staff, and parents. The results showed that there were differences in recognition among the groups regarding each changed item in the 2013 child care center accreditation system, but overall, the groups evaluated the main amendments positively and the changes were considered appropriate and necessary. However, it was found that in-depth reviews are needed of procedure unification to check the basics to require legal compliance; management of unaccredited centers such as valid period reduction and no accreditation, or limit for re-accreditation application; and the burdens of child care centers about surprise visits and notice of inspection dates in advance.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.4
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• pp.342-354
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• 2008

Some statistical characteristics of deepwater waves along the Korean coast have been investigated using various sources of wave measurement and hindcasting data. For very large waves comparable to design waves, it is recommended to use the average value of the empirical formulas proposed by Shore Protection Manual in 1977 and by Goda in 2003 for the relation between significant wave height and period. The standard deviation of significant wave periods non-dimensionalized with respect to the mean value for a certain significant wave height varies between 0.04 and 0.21 with a typical value of 0.1 depending upon different regions and different ranges of significant wave heights. The mean and standard deviation of the principal deepwater wave direction are presented at the 106 coastal grid points along the Korean coast. For relatively large waves, the probability density function of the directional spreading parameter $s_{max}$ is expressed as a lognormal distribution. The most suitable frequency spectrum in the Korean coast is the TMA spectrum. The probability density function of the peak enhancement factor $\gamma$ is also expressed as a lognormal distribution, with its mean value of 2.94, which is close to the value in the North Sea.

• The Journal of Engineering Geology
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• v.22 no.1
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• pp.15-25
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• 2012

Probabilistic design methods have been used as a design standard in Korea and abroad for achieving reasonable design by considering the statistical uncertainties of soil properties. In this study, the following techniques for reflecting geotechnical uncertainty are analyzed: quantification of the uncertainties of geotechnical random variables, and consideration of economic feasibility in design by minimizing the uncertainties related to the number of samples. To quantify the uncertainties, the techniques were applied to soil properties obtained from samples collected and tested in the field. The results showed an underestimation of the standard deviation by the 3-sigma approach in comparison with calculations using data from the samples. This finding indicates that economical design is possible in terms of probability. However, when compared with the Bayesian approach, which does not consider the number of samples, variability in the 3-sigma approach is underestimated for some variables. This finding also indicates a safety issue, whereas the number of samples based on the Bayesian approach showed the lowest variance. The variance of the probability density function showed a marked decrease with increasing number of samples, to converge at a certain level when the number exceeds 25. Of note, the estimation of values is more reliable for random variables having low variability, such as soil unit weight, and can be obtained with a small number of samples.

• Journal of KIISE:Software and Applications
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• v.37 no.1
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• pp.1-8
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• 2010

Recently lots of attention has been paid to gene set analysis for identifying differentially expressed gene-sets between two sample groups. Unlike earlier approaches, the gene set analysis enables us to find significant gene-sets along with their functional characteristics. For this reason, various novel approaches have been suggested lately for gene set analysis. As one of such, PAGE is a parametric approach that employs average difference (AD) as an expression metric to quantify expression differences between two sample groups and assumes that the distribution of gene scores is normal. This approach is preferred to non-parametric approach because of more effective performance. However, the metric AD does not reflect either gene expression intensities or variances over samples in calculating gene scores. Thus, in this paper, we investigate the usefulness of several other expression metrics for parametric gene-set analysis, which consider actual expression intensities of genes or their expression variances over samples. For this purpose, we examined three expression metrics, WAD (weighted average difference), FC (Fisher's criterion), and Abs_SNR (Absolute value of signal-to-noise ratio) for parametric gene set analysis and evaluated their experimental results.

• Korean Journal of Social Welfare
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• v.57 no.2
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• pp.205-230
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• 2005

This study empirically examines if there is a certain linkage between the production regimes and welfare systems; and if linked, how they are linked. It also investigates what the different regimes performed in terms of economic growth and redistribution. As a matter of fact, we have a series of studies that explores structural diversity of production and welfare. However, the existing studies are limited in that they consider only specific facets of the structure, although the structure of welfare capitalism should be studied as a comprehensive whole. This is the gap which this study tries to overcome. The study is composed of two major parts. The first one is the cluster analysis that examines if Esping-Andersen's notion about three different welfare regime and the thesis of diversity of capitalism can be dealt within a single research framework. The second is the ANOVA analysis investigating if variables of production and welfare are to be statistically different in the trichotomy framework. According to the result of the analyses, we can find at least two important evidences about institutional complementaries of production and welfare. First, Esping-Andersen's framework is useful to comprehensively deal with production as well as welfare. Secondly, there are statistically different regimes of production and welfare in the context of political economic and social policy variables. What is the most striking conclusion of the study is that there is no difference among the regimes in terms of the level of economic efficiency; while we can find a huge differences in terms of the level of welfare effectiveness. In conclusion, there is no substantive evidence to argue that welfare is innately antithesis of economic growth.

• International Journal of Highway Engineering
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• v.14 no.2
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• pp.55-61
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• 2012

Road signs are important facilities in terms of providing information to driver, they are helpful for driver's judgment as deliver it's own information. However if there is occurrence dew on the road sign because of the change of temperature and humidity, it can be cause of accidents. Therefore it is necessary to develop anti-dew or dew resistance technology. In this research the anti-dew technologies such as insulation road sign and anti-dew film were compared with normal road sign, and the effectiveness analysis was conducted for each alternatives. The quantity of dew on the road sign was check using ANOVA and Tukey HSD and the relation between the retro-reflectivity and quantity of dew on the sign was check using Pearson correlation coefficient. As a result, the sample of anti-dew film attached road sign showed lesser quantity of dew compared with normal road sign. After 90 seconds, the difference of dew quantity for anti-dew film and insulation road sign showed statistically significant result. The relation of between quantity of dew and retro-reflectivity was inverse correlation. As a result, when analyzed the quantity of dew and retro-reflectivity a point of view anti-dew effectiveness, the anti-dew film and insulation road sign showed meaningful result.

• The Korean Journal of Applied Statistics
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• v.22 no.3
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• pp.585-594
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• 2009

Researchers of microarray experiment transpose processed images of raw data to possible data of statistical analysis: it is preprocessing. Preprocessing of microarray has image filtering, imputation and normalization. There have been studied about several different methods of normalization and imputation, but there was not further study on the order of the procedures. We have no further study about which things put first on our procedure between normalization and imputation. This study is about the identification of differentially expressed genes(DEG) on the order of the preprocessing steps using two-dye cDNA microarray in colon cancer and gastric cancer. That is, we check for compare which combination of imputation and normalization steps can detect the DEG. We used imputation methods(K-nearly neighbor, Baysian principle comparison analysis) and normalization methods(global, within-print tip group, variance stabilization). Therefore, preprocessing steps have 12 methods. We identified concordance measure of DEG using the datasets to which the 12 different preprocessing orders were applied. When we applied preprocessing using variance stabilization of normalization method, there was a little variance in a sensitive way for detecting DEG.

• Journal of Korean Society of Transportation
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• v.28 no.1
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• pp.39-49
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• 2010

Although many studies have been carried out on the pattern of behavior of drivers which result from the provision of traffic information, there have been few detailed studies on the composition of message, method for message expression, timing of provision, point of provision, media for provision, changes by traffic condition, etc. This study was intended to provide an insight into the changes in the characteristics related to the provision of information by analyzing how the patterns of information utilization change depending on the traffic condition and reclassifying such patterns according to the characteristics of media. Unlike the existing studies, this study adopted the traffic condition, using rate of information media, and the correlation coefficient label as the basis for information media classification, and categorized them into passive utilization media, active utilization media, and past experience in order to ensure the statistical reasonability. The categorized using rate of information media and traffic condition was found to have a positive(+) correlation with the travel speed in the case of passive utilization media during both consecutive holidays(Korea's traditional Thanksgiving day) and weekends, but had a negative(-) correlation with the positive utilization media and past experience. The rate of decision to take a detour based on the past experience was high at the condition of congestion or slow during both consecutive holidays and weekends, but the rate of decision to take a detour through passive utilization media was high in a smooth traffic. In other words, if the traffic condition worsens, using rate of passive utilization media would be low while the diversion rate would be high which uses the active utilization media and past experience. Therefore, it should be established to suit the traffic condition and media characteristics for strategies of traffic distribution through drivers' diversion behavior on weekends and consecutive holidays.