• Journal of the Korean Data and Information Science Society
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• v.20 no.2
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• pp.261-272
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• 2009

Kolmogorov-Smirnov (K-S) statistic has been widely used for testing homogeneity of two distributions in the credit rating models. Joseph (2005) used K-S statistic to obtain validation criteria which is most well-known. There are other homogeneity test statistics such as the Cramer-von Mises, Anderson-Darling, and Watson statistics. In this paper, these statistics are introduced and applied to obtain criterion of these statistics by extending Joseph (2005)'s work. Another set of alternative criterion is suggested according to various sample sizes, type a error rates, and the ratios of bads and goods by using the simulated data under the similar situation as real credit rating data. We compare and explore among Joseph's criteria and two sets of the proposed criterion and discuss their applications.

• Journal of Korean Society of Steel Construction
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• v.28 no.5
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• pp.313-323
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• 2016

Seven types of tests were conducted to experimentally evaluate the material properties of ultral-thick (or 120mm-thick) SM490TMC plate. The investigation of through-thickness properties was among the most significant considerations. All chemical and mechanical test results showed the through-thickness homogeneity as required and conformed to the KS(Korean industrial Standards), although the thickness was 1.5 times thicker than the thickness limit (80mm) imposed by Steel Structure Design Code. No reduction in the yield strength of 120mm-thick SM490TMC plate is recommended for design.

• Communications for Statistical Applications and Methods
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• v.6 no.1
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• pp.151-158
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• 1999

Distribution-free tests are proposed for AB/BA 2*2 cross-over design data based on placements introduced by Orban and Wolfe(1992). In this paper we suggest the homogeneity test or carry-over effects and also suggest the test for direct effects and the test for period effects under the same carry-over effects. The properties such as iterative asymptotic distribution for the proposed tests are discussed.

• Journal of Soil and Groundwater Environment
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• v.19 no.6
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• pp.49-58
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• 2014

This study was implemented as a part of the experiment to develop two kinds of soil-based Benzo[a]pyrene (BaP) proficiency testing materials (PTMs) for soil analysis. A test was carried out for the check of solubility of the reference material (high purity reagent) using several solvents. Another test was also conducted for the evaluation of homogeneity and stability of two kinds of candidate soil reference materials. The test analysis of BaP in terms of the candidate materials was conducted according to the Standard Soil Analytical Methods by Ministry of Environment. Dissolution of the reference material was shown to vary depending on solvent type and was higher in the order of Dichloromethane > Acetone > Acetone/MeOH (9 : 1) > N-hexane. In addition, the slope on calibration curve for BaP standard solutions was largest on BaP standard solutions prepared with dichloromethane of the tested solvents. Such tendency appeared egually in the commercial BaP standard solution. Therefore, it is thought to be reasonable to use dichloromethane as the solvent in case of the standard stock solution that is used for the measurement of BaP concentration in soil. ISO 13528 and IUPAC protocol were used for verification of homogeneity on the two kinds of soil candidate materials, Both candidate materials were sufficiently homogeneous. Stability assessment of the two candidate materials was made according to ISO Guide 35 and the result showed that both batches did not have any long-term and short term stability issues that might occur during shipping. However, monitoring results of BaP concentration in soil showed that BaP concentration of the two batches measured at 15 days after the sample preparation was reduced by about 24~37% compared with that of the samples measured on 0 day of the sample preparation. Identification was done with several treatments such as irradiation and sterilization etc. The major cause was shown to be irradiation to the samples.

• Journal of Oriental Neuropsychiatry
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• v.29 no.3
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• pp.145-163
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• 2018

Objectives: The study was designed to provide clinical evidence of homogeneity in analysis of the herbal medicine, Guipi decoction in treating insomnia, using a t-test of randomized controlled trials (RCTs). Methods: This study included RCTs that verified homogeneity of Guipi decoction in treating insomnia. Literature studies of CNKI (Chinese National Knowledge Infrastructure Database) were performed. The basic components group was made to the Guipi decoction of the Yixuerumen?s text. The excluded group was created with the number of herbs excluded from the basic components group. T-test performed that the effective rate in the basic components group and excluded groups. Results: The basic components of Guipi decoction contain Atractylodis Rhizoma Alba, Poria Sclerotium (Poria Sclerotium Cum Pini Radix), Polygalae Radix, Astragali Radix, Zizyphi Semen, Angelicae Gigantis Radix, Aucklandiae Radix, Glycyrrhiza uralensis Fischer, Ginseng Radix (Codonopsis Pilosulae Radix), Longanae Arillus. Herbs excluded from the basic components group were Longanae Arillus, Ginseng Radix (Codonopsis Pilosulae Radix), Glycyrrhiza uralensis Fischer and herbs added to the basic components group were Polygonum multiflorum Thunberg, Schisandrae Fructus, Salviae Militiorrhizae Radix, Paeoniae Radix Alba (in order from the most used to the least). T-test revealed the effective rate in the basic components group was not statistically significant compared to the excluded groups (p=0.161/p=0.162/p=0.103). Conclusions: Effectiveness in treatment of basic components of Guipi decoction and excluded groups were revealed to be homogeneous in treating insomnia. As the number of herbs in the basic components group decreased, mean value in effectiveness of treatment also decreased consequentially. However, there were no statistical significances.

• Journal of Korea Water Resources Association
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• v.38 no.8 s.157
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• pp.617-629
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• 2005

In this paper, a hypothesis is tested that division of non-monotonic time series into monotonic parts will improve the estimation of trends through increased homogeneity in direction of time-variation using LOWESS smoothing and seasonal Kendall test. From the trend analysis of generated time series and water temperature, discharge, air temperature and solar radiation of Lake Daechung, it is shown that the hypothesis is supported by improved estimation of trends and slopes. Also, characteristics in homogeneity variation of seasonal changes seems to be more clearly manifested as homogeneity in direction of time-variation is increased. And this will help understand the effects of human intervention on natural processes and seems to warrant more in-depth study on this subject. The proposed method can be used for trend analysis to detect monotonic trends and it is expected to improve understanding of long-term changes in natural environment.

• Journal of Korean Academy of Nursing
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• v.27 no.1
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• pp.109-119
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• 1997

This study has been attempted to set up the strategies of the nursing which can promote the activity performance for early rehabilitation for the patients by examining the effect of the structured patient education on the early rehabilitation knowledge and activity performance of the C.V.A patients. The study method has been done by investigating the experiment group and control group in advance through the question papers and interview and observation on 65 patients who had been hospitalized at oriental medicine hospital of K Medical Center from July 1st 1995 to the end of Sep, 1995. The analysis of the collected material had been done for the homogeneity test in which general characters of experiment group and control group had been tested by X²and the homogeneity test of ADL by t-test. To test the hypothesis the t-test had been given for the difference of the early rehabilitation knowledge and activity performance between the two groups and the correlation between early rehabilitation knowledge and activity performance had been tested by Pearson's Correlation Coefficient. The result of the test of the hypothesis is as the below. 1 The 1st hypothesis “The experiment group which had received the structured education should be higher in the early rehabilitation knowledge than the control group” was supported(t=4.45. p=.000). 2. The 2nd hypothesis “The experiment group which received the structured education should be higher in the early rehabilitation activity performance than the control group”was supported(t=2.11, p=.036). 3. The 3rd hypothesis “The higher the early rehabilitation knowledge of the patient the higher the activity performance degree” was rejected (r=.1546, p=.219). In conclusion, the patients who received the structured education showed the increase in the degree of early rehabilitation knowledge and activity performance, so it has been judged that education has been prerequisite in increasing the knowledge and activity performance of early rehabilitation.

• Journal of Environmental Science International
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• v.20 no.9
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• pp.1183-1190
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• 2011

This study was aimed to establish the evaluating protocol and standard assessment for genetically modified (GM) hot pepper and to find out a proper statistic method to analyze for equality of agricultural characters between GM and non-GM pepper lines. GM and non-GM hot pepper lines were cultivated in two GMO fields in the middle region of Korea and total of 52 agricultural characters were collected during the plant growing season for 4 years, 2007 to 2010. Levene's test was conducted to confirm the homogeneity of raw data before statistic analysis. Two-way ANOVA in the multivariate tests and t-test were conducted to analyze 52 agricultural characters in order to find out the equality between H15 and P2377. From the statistical analysis through two-way ANOVA, 16 out of 16 plant growth traits, 9 out of 18 green fruit traits and 7 out of 18 red fruit traits among 4 years and 9 out of 16 plant growth traits, 4 out of 18 green fruit traits and 3 out of 18 red fruit traits between H15 and P2377 have shown the statistic differences. With the same raw data of 52 agricultural characters, t-test was also conducted. Based on the result from t-test, only 1 out of 16 plant growth traits, 2 out of 18 green fruit traits and 1 out of 18 red fruit traits have shown the differences between H15 and P2377, so that it was concluded that there is no statistic difference between H15 and P2377 in terms of agricultural characters. Also, the t-test is a proper statistic method to analyze each trait between GM and its control lines in order to evaluate agricultural characters.

• Journal of Korean society of Dental Hygiene
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• v.23 no.2
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• pp.105-113
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• 2023

Objectives: The purpose of this study is to verify the usefulness and practicality of the program in the daily life of the elderly by performing a three-dimensional tongue muscle exercise for the elderly to identify the dysphagia, swallowing ability, and tongue pressure. Methods: The subjects of the study were 29 elderly people aged 65 or older living in Busan, divided into a oral exercises group and tongue strength training program combined with oral exercises group, and operated 16 times for 8 weeks twice a week, and the pre and post-program evaluation was conducted in the 1st and 8th weeks. For variable selection, 7 general characteristics, 5 oral health-related characteristics, 5 Likert scale for swallowing disorder, repetitive swallowing ability test for swallowing power measurement, and tongue pressure measurement was used. Data analysis was conducted using SPSS window program 25.0 version (IBM), general characteristics and homogeneity tests, oral health-related characteristics and homogeneity tests were chi-square test, swallowing disorder, swallowing ability, and change in tongue pressure were paired t-test, Wilcoxon signed rank test, t-test, Mann-Whitney U test for swallowing disorder and changes in swallowing ability and tongue pressure, and Spearman's correlation for the relationship between swallowing disorder and swallowing ability and tongue pressure. Results: As a result of tongue strength training program combined with oral exercise, both relieve swallowing disorder and improve low eating and tongue pressure than oral exercise, and the difference in improvement effects of both relieve swallowing disorder, swallowing ability, and tongue pressure is higher. Conclusions: Based on the results of this study, it is believed that simple and practical oral muscle function reinforcement products and practical use are needed, and institutional devices to seek oral health promotion programs for the elderly are needed.

• Journal of Korean Society for Quality Management
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• v.24 no.2
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• pp.87-101
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• 1996

To investigate the impacts of ISO 9000 QA systems to the Korean industry quality improvement as well as quality consciousness, QA related data has been surveyed from quality assurance engineers who have worked on ISO 9000 certification activities and has been analyzed using relevant tabulations of five(5) scale or x2-homogeneity test method. Hypotheses to the unchange in the quality consciousness are tested in terms of x2-homogeneity in order to compare the consciousness of pre-certification with that of post-certification. The level of quality management of Korean manufacturing industry has been high-lighted by use of quality maturity grid.