• Water for future
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• v.5 no.2
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• pp.30-43
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• 1972

The paper describes on the hydrologic analysis of point rainfall data of the three major areas, such as in Seoul, Pusan and Taegu. Scheme of the paper is analyzed five research cases. Contents of the analysis are carried out five kinds of transformed variables for determination of rainfall distribution types and two kinds of reliability tests on unusual(extraordinary) values each rainfall durations:short durations, long durations, long durations, monthly and yearly. Rainfall depth probability had been computed methods of hydrologic amounts analysis namely logarithmic transformations or Gumbel-Chow method and so on, but in this paper it is calculated log xi, n-square root transformations by using normal distribution function and normalization of rainfall distributions is examined graphical tests and $X^2-test$(chi-square test). Furthermore, rainfall depth probability is calculated taking into account the safty factors of project life of hydraulic structures. We think it is advanced contents that considering priceless experiences, the life of structures, conditions and more problems of planning engineers and designers, proposed rainfall amounts(proposed values) are presented charts or figures.

• Structural Monitoring and Maintenance
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• v.9 no.3
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• pp.221-235
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• 2022

Among nondestructive damage detection methods, impedance-based methods have been recognized as an effective technique for damage identification in many kinds of structures. This paper proposes a method to detect cracks in metal structures by combining electro-mechanical impedance (EMI) responses and artificial neural networks (ANN). Firstly, the theories of EMI responses and impedance-based damage detection methods are described. Secondly, the reliability of numerical simulations for impedance responses is demonstrated by comparing to pre-published results for an aluminum beam. Thirdly, the proposed method is used to detect cracks in the beam. The RMSD (root mean square deviation) index is used to alarm the occurrence of the cracks, and the multi-layer perceptron (MLP) ANN is employed to identify the location and size of the cracks. The selection of the effective frequency range is also investigated. The analysis results reveal that the proposed method accurately detects the cracks' occurrence, location, and size in metal structures.

• Journal of Korean Society of Forest Science
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• v.86 no.3
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• pp.365-377
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• 1997

Much of the Cumberland Plateau of Tennessee, USA is in mixed hardwoods for which there are no applicable growth and yield predictors. Use of site index as a variable in growth and yield prediction models is limited in most stands because their history is not known and many may not be even-aged. Landtypes may offer an alternative to site index for these mixed stands because they were designed to include land of about equal productivity. To determine vegetation by landtype, dependency between landtype and detailed forest type was tested with Chi-square. Differences in productivity among landtypes were tested by employing regression analyses and analysis of variance(ANOVA). Basal area growth was fitted to the nonlinear models developed by Moser and Hall(1969). Basal area growth and volume growth were also predicted as a function of initial total basal area and initial volume with linear regression by landtype and by landtype class. Differences in basal area growth and volume growth by landtype were tested with ANOVA. Dependency between site class and landtype was tested with Chi-square. Vegetation types seem to be related to landtypes in the study area although the validity of the test is questionable because of a high proportion of sparsely occupied cells. No statistically significant differences in productivity among landtypes were found in this study.

• Journal of Korean Institute of Industrial Engineers
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• v.14 no.1
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• pp.51-56
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• 1988

A spectrum analysis method is presented with an example as an aid to Box and Jerkins' model identification procedure, where the theoretical spectrum of ARMA model and its confidence intervals derived by chi-square distribution are compared. An APL (A Programming Language) program for the method is developed for the 16-bit personal computer.

• Proceedings of the Korea Society of Costume Conference
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• 2003.10a
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• pp.55-55
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• 2003

The purpose of this study was to find out apparel fit satisfaction according to item (jacket, pants, skirt) by body perception and body satisfaction. This research was done by a survey method. Statistical analysis such as frequency, a percentage, arithmetic average, standard deviation and Pearson's correlation, Crosstabs(Chi-square) were used for data analysis.

• Proceedings of the Korea Society of Costume Conference
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• 2003.10a
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• pp.82-82
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• 2003

The purposes of this study were to examine the purchasing and using behaviors of cosmetics according to women's consumption propensity. A self administered Questionnaire was used and the subjects were 600 women of 20s and 30s in Jeonbuk Province. The data collecting periods were July, 2003. Means, percentages, and frequency were calculated. And factor analysis, cluster analysis, one-way ANOVA, and Chi-square test were done by use of SPSS PC (Ver. 10.0).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.1
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• pp.11-16
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• 1985

The performance analysis of serial search spread spectrum synchronization system is carried out. To evaluate the synchronization probabilities, two chi-square densities for signal plus noise and noise only are derived. Then Neyman-Pearson scheme is applied to determine the threshold of the synchronization system. The synchronization probability curves are shown as a function of threshold and signal to noise ratios.

• Journal of Korean Medicine Rehabilitation
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• v.20 no.4
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• pp.105-130
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• 2010

Objectives : The purpose of this study was to assess the statistical methods errors used in the journal of Oriental Rehabilitation Medicine(JORM) and to identify the types of errors in statistical analysis. Methods : We reviewed quantitative articles that were published in the JORM from January 2005 through October 2009. Those were not used by statistical analysis such as literature studies, case study, review articles were not included in this analysis. A total of 296 articles was reviewed. We evaluated the adequacy and the validity of the statistical techniques with our checklist established be modified Lee's checklist, and three statistical evaluators assessed together to minimize bias. Results : Of the 222 articles, 213 were used in inferential and descriptive statistics. Of those 80% of articles adopting descriptive and inferential statistics were detected having statistical errors. One articles used 1.7 statistical method unit generally. Most frequently employed statistics were student t-test, one way ANOVA. pearson correlation analysis, Mann-whitney U test, paired t-test, and chi-square test in their order. However, most frequent statistics having errors were similar in order. The most common statistic errors were as follow: 1. absence of normality test, 2. misuse between paired test and unpaired test, 3. wrong choice of repeated measures analysis without consideration of time variables, 4, increase of Type I error by using inappropriate multiple test, 5. inappropriate application of discrete or categorical data instead of continuous data in correlation analysis, 6. poor consideration of basic consumption in chi-square test, 7. confusion between frequency comparison and average comparison, 8. mentioning the statistical technique without using it. Conclusions : We found various mistake or misuses in the applications of statistical methodologies in the articles published in the JORM. Careful consideration of statistical use and review from the specialist of statistics are warranted for improving the quality of JORM.

• Journal of Integrative Natural Science
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• v.7 no.3
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• pp.208-213
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• 2014

National-wide and/or large scale sample surveys generally use complex sample design. Traditional Pearson chi-square test is not appropriate for the categorical complex sample data. Rao-Scott suggested an adjustment method for Pearson chi-square test, which uses the average of eigenvalues of design matrix of cell probabilities. This study is to compare the efficiency of Rao-Scott first order adjusted test to Wald test for homogeneity between two populations using 2009 Gyeongnam regional education offices's customer satisfaction survey (2009 GREOCSS) data. The 2009 GREOCSS data were collected based on stratified three-stage cluster sampling with probability proportional to size. The empirical results show that the Rao-Scott adjusted test statistic using only the variances of cell probabilities is very close to the Wald test statistic, which uses the covariance matrix of cell probabilities, under the 2009 GREOCSS data based. However it is necessary to be cautious to use the Rao-Scott first order adjusted test statistic in the place of Wald test because its efficiency is decreasing as the relative variance of eigenvalues of the design matrix of cell probabilities is increasing, specially more when the number of degrees of freedom is small.

• Journal of Korean Physical Therapy Science
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• v.7 no.2
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• pp.697-709
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• 2000

The purpose of this study was to evaluate the effectiveness of ElectroMyoscope(Electro_Acuscope and Myopulse) in tissue repairing on fatigue quadriceps femoris(rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis). Subjects were female adult volunteers with (n=13) and without (n=5) chronic fatigue muscle pain. We needed to fatigue the rectus femoris by overusing of a Cybex machine exercise. We turned the Electro-Myoscope to treatment mode and treated with treatment probe on the fatigue muscle, then turned instrument back to EMG and took the reading. The results indicated that the reading after the treatment was lower than before the treatment. A two-tailed t-test and Chi square indicated significant results(P<.03). It appears that the Electro-Myoscope is effective in treatment on the fatigue muscle.