• Journal of the Korea Computer Industry Society
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• v.3 no.12
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• pp.1651-1658
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• 2002

Recently power cable used generally in Korea, because installation is very simple and it has high stability. It confirms to the requirements of IEEE std. 404-1993 by factory testing, but many problems of insulated cable systems are caused by internal defects of the joint part which have to be mounted ensile. Especially, fault rates are arise from impurities or voids. A suitable solution for a monitoring of power cable during the after-laying test and service is partial discharge detection. The artificial defects between cable joint(EPR) and insulator(XLPE) interface are considered in this research to investigating the partial discharge characteristics. ${\varphi}$-q-n properties were detected using data acquisition system and Maximum charge($q_{max}$), repetition rate(${\={n}$), average charge(${\={q}$), Unbalance rate of ${\={n}$ and ${\={q}$ are calculated in order to analysis partial discharge properties quantitatively from this statistic value.

• The Korean Journal of Applied Statistics
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• v.22 no.6
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• pp.1249-1263
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• 2009

The power function in sample size determination has to be characterized by an appropriate statistical test for the hypothesis of interest. Nonparametric tests are suitable in the analysis of ordinal data or frequency data with ordered categories which appear frequently in the biomedical research literature. In this paper, we study sample size calculation methods for the Wilcoxon-Mann-Whitney test for one- and two-dimensional ordinal outcomes. While the sample size formula for the univariate outcome which is based on the variances of the test statistic under both null and alternative hypothesis perform well, this formula requires additional information on probability estimates that appear in the variance of the test statistic under alternative hypothesis, and the values of these probabilities are generally unknown. We study the advantages and disadvantages of different sample size formulas with simulations. Sample sizes are calculated for the two-dimensional ordinal outcomes of efficacy and safety, for which bivariate Wilcoxon-Mann-Whitney test is appropriate than the multivariate parametric test.

• Korean Journal of Agricultural Science
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• v.15 no.2
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• pp.164-173
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• 1988

This study is to analyse marketing and industrial structure of meat processing industry and to examine it's current situation related to agriculture. For this purpose 1. This paper surveys the history of meat processing industry, and analyses current situation of meat processing industry, based upon economic statistic data. 2. For the research of marketing structure of meat processing products, this paper not only ciassifies into three catagories; the supply of raw meat, main marketing organization, and path, but measures magnitude of Marketing Bill and Farmer's Share practically through statistic data and an on-the-spot survey. 3. This study also attempt to explain the relation of meat processing industry and the other industry and role of meat processing industry is Korean economy by the use of input-output table. The results of the study are as follows; 1. The meat processing industry in Korea produces low quality, and expensive raw meat with limited quality, inefficiency of marketing structure, and unrelated livestock and meat processing industry. 2. Korea market structure of meat processing products has been changed into oligopoly from monopoly by a new corporation entered into monopoly and the size of meat processing market firms has been normalized. 3. Meat processing industry is very important considering with its high back-linkage-effect. In order to develop meat processing industry and marketing, it is essential that operation of intergrated meat market center, meat market center should be efficiently operated. The efficient utilization of domestic resource for raw meat and development of processing technique have to be required, by means of the governmental support.

• Journal of Trauma and Injury
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• v.30 no.4
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• pp.131-139
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• 2017

Purpose: Trauma systems have been shown to decrease injury-related mortality. The present study aimed to compare the mortality rates of patients with major trauma (injury severity score >15) treated before and after the establishment of a level I trauma center. Methods: During this 20-month study, participants were divided into pre-trauma center and trauma center groups, and trauma and injury severity score (TRISS) method was used to compare mortality rates during 10-month periods before and after the establishment of the trauma center (October 2013 to July 2014 vs. October 2014 to July 2015). Results: Of the 541 total participants, 278 (51.5%) visited after the establishment of the trauma center. The Z and W statistics indicated better outcomes in the trauma center group than in the pre-trauma center group (Z statistic, 2.635 vs. -0.700; W statistic, 4.640). The trauma center group also exhibited meaningful reductions in the time interval from the emergency department (ED) visit to emergency surgery (118.0 minutes vs. 142.5 minutes, p=0.020) and the interval from the ED visit to intensive care unit admission (202.0 minutes vs. 259.0 minutes, p=0.035) relative to the pre-trauma center group. Conclusions: The TRISS and multivariate analysis revealed significant improvements in survival rates in the trauma center group, compared to the pre-trauma center group.

• The Korean Journal of Applied Statistics
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• v.23 no.5
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• pp.955-966
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• 2010

Canonical correlation biplot is a useful biplot for giving a graphical description of the data matrix which consists of the association between two sets of variables, for detecting patterns and displaying results found by more formal methods of analysis. Nevertheless, when some values are missing in data, most biplots are not directly applicable. To solve this problem, we estimate the missing data using the median, mean, EM algorithm and MCMC imputation methods according to missing rates. Even though we estimate the missing values of biplot of incomplete data, we have different shapes of biplots according to the imputation methods and missing rates. Therefore we use a RMS(root mean square) which was proposed by Shin et al. (2007) and PS(procrustes statistic) for measuring and comparing the shape variability between the original biplots and the estimated biplots.

• International Journal of Highway Engineering
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• v.12 no.2
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• pp.43-49
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• 2010

This study deals with the traffic accident of the Cheongju arterial link sections. The purpose of the study is to develop the traffic accident model. In pursuing the above, this study gives particular attentions to developing the ZAM(zero-altered model) model using the accident data of arterial roads devided by 322 small link sections. The main results analyzed by ZIP(zero inflated Poisson model) and ZINB(zero inflated negative binomial model) which are the methods of ZAM, are as follows. First, the evaluation of various developed models by the Vuong statistic and t statistic for overdispersion parameter ${\alpha}$ shows that ZINB is analyzed to be optimal among Poisson, NB, ZIP(zero-inflated Poisson) and ZINB regression models. Second, ZINB is evaluated to be statistically significant in view of t, ${\rho}$ and ${\rho}^2$ (0.63) values compared to other models. Finally, the accident factors of ZINB models are developed to be the traffic volume(ADT), number of entry/exit and length of median. The traffic volume(ADT) and the number of entry/exit are evaluated to be the '+' factors and the length of median to be '-' factor of the accident.

• Journal of Environmental Impact Assessment
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• v.5 no.2
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• pp.21-31
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• 1996

To assess the impact resulted from the slag dumping, we studied that the changes in the concentration of heavy metal were researched through the statistic analysis at 4 stations in Yongil bay, Korea from 1988 to 1995. And in order to clarify resulting from the changes in heavy metal concentration due to be leaked out from dumped slag, it was fulfilled experiments of the slag extraction. In the extracting experiment, Pb and As were only leaked out from slag aged during 10 days but all of heavy metals were not from it aged during 90 or 180 days. It was found that the concentrations of heavy metals in sea water of vincinity of slag dumping area were still remained in similar, comparing with it of control site(site 4) when they were by analysed statistic method, anova test and Mann-Whitney test. The slag recycling ratio of our country is lower than foreign country. While we need to apply a new process for phosphate treatment, foreign country already apply a slag to phosphorous removal. We suggest that slag dumping cannot putatively affected the changes in the concentration of heavy metal. And we thought that impact of heavy metal induced by slag dumping was not severe. So, it is necessary to utilize this process in phosphorous removal, like a foreign country.

• Journal of the Korean Society of Earth Science Education
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• v.5 no.1
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• pp.60-67
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• 2012

The purpose of this study is to find out the effect of hypothesis formulations using abduction on science processing skills and the creative thinking activities. As the subject, 2 classes in the $6^{th}$ grade of B elementary school located in Busan were selected. Through the pre/post inspection design between experiment and comparison class, the units of science courses in the second semester of $6^{th}$ grade '1. A change in the weather' and '2. Various gases' were applied. The results were as follows: Firstly, the test on science processing skills showed that there was not statistic meaningful differences between the two groups. And, in the sub-parts, there was not statistic meaningful differences between the two groups. Secondly, it was observed that it would have a meaningful effect to improve the creative thinking activities of students who performed hypothesis formulation using abduction. Especially, through this, the experimental class gave a positive effect on the 'Fluency' and 'Elaboration', one of lower categories of the creative activities. The results of 'Flexibility' and 'Originality' in the experimental class were higher than those of students in the comparative class. However, according to statistical analysis, this result is meaningless. Thirdly, on the survey about the hypothesis formulation using abduction, many students thought that this learning method was very interesting and helpful to study science. In addition, it was observed that the ability to use abduct thinking was improved more than ever before.

• Journal of Sasang Constitutional Medicine
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• v.22 no.4
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• pp.49-55
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• 2010

1. Objectives The purpose of this study is to assess the statistical methods used in the Journal of Sasang Constitutional Medicine and to identify the types of errors in the statistical analysis. 2. Methods We have reviewed quantitative articles published in the Journal of Sasang Constitutional Medicine from 2000 to 2009. Except for the case report, a total of 505 articles was reviewed by year. We focused on the methods of statistics in these articles. We have analysed the number of thesis used the statistical methods, the number of the statistical methods, the types of the statistical methods, and the errors of the statistical methods with the object of 202 thesis used the statistical method. 3. Results 1. Of the 370 articles, 202 used inferential statistics. 2. The most dominant was the thesis with one type of the statistical method forming 61.9% (125 thesis) of the total. 3. The ANOVA was the statistic of choice overall (40.1%), followed by the t-test (35.6%). 4. By examining the errors of the statistical methods, there were 49 thesis with errors among 81 thesis using ANOVA, 25 thesis among 72 thesis using t-test, and 18 over 62 thesis using chi-squared test. 4. Conclusions We have found various mistakes or misuses in the applications of statistical methodologies in the articles published in the Journal of Sasang Constitutional Medicine. It is necessary to present the cases of inappropriate statistical methods in order to improve the quality of academic researches. So long as Sasang constitutional medicine uses the statistical methods, researchers should fully examine and be aware of the statistical methods which they wish to use through other research articles, and statistic publications.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.436-447
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• 2019

Entrepreneurship has been received enormous attention all around the world in terms of economic prosperity of local society and a nation. This paper explores the critical factors which influence entrepreneurship, particularly how role models affects social competence and entrepreneurship of Korean and Chinese university students. Total 440 students participated in the study; Korea(n=224) and China(n=216). Verifying mediating effect of social competence was another aim of this study. Four hypotheses were suggested to assess the extent to which they prove the students' perceptions with hierarchical multiple regression analysis(PASW Statistic 18). Our findings showed that role models have positive relationships with social competence as well as entrepreneurship. Social competence influences entrepreneurship significantly, too. Social competence has also a partial mediating effect in relationship between role models and entrepreneurship. We presented both theoretical contribution and practical implication for school authorities and policy makers as to the effective pedagogy for promoting entrepreneurship of university students.