• Research in Mathematical Education
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• v.18 no.1
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• pp.75-87
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• 2014

It is central to use a scale to measure a person's level of a construct in mathematics education research. This article explains a practical process through which a researcher rapidly can develop an instrument to measure the construct. The process includes research questioning, reviewing the literature, framing a background theory, treating the data, and reviewing the instrument. The statistical treatment of data includes normality analysis, item-total correlation analysis, reliability analysis, and factor analysis. A virtual example is given for better understanding of the process.

• Journal of the Korean Data and Information Science Society
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• v.12 no.2
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• pp.35-45
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• 2001

We introduce a new percentile envelope for diagnosing supernormality in regression analysis. Furthermore, we compare this percentile envelope, which is much simpler and easier, with Atkinson's and Flack and Flores' envelopes. Using percentile envelope, we investigate characteristics of normal probability plots with envelope for error distributions when supernormality is occurred. We give cautions that test result for normality assumption of errors can be reached the wrong conclusion by supernormality.

• ETRI Journal
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• v.18 no.3
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• pp.207-213
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• 1996

This paper proposes a new nonparametric test for testing the null hypothesis that the MRL is constant against the alternative hypothesis that the MRL is decreasing (increasing) for ramdomly censored data. The proposed test statistic is a L-statistic, and we use L-statistic theory to establish its asymptotic normality of the test statistic. We discuss the efficiency loss due to censoring and also calculate the asymptotic relative efficiencies of our test statistic with respect to the Chen, Hollander and Langberg's test for several alternatives.

• Journal of the Korean Data and Information Science Society
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• v.10 no.1
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• pp.207-214
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• 1999

Optimal estimating functions for a class of autoregressive models with GARCH(1,1) error are discussed. The asymptotic properties of the estimator as the solution of the optimal estimating equation are investigated for the models. We have also some simulation results which suggest that the proposed optimal estimators have smaller sample variances than those of the Conditional least-squares estimators under the heavy-tailed error distributions.

• Journal of the Korean Data and Information Science Society
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• v.15 no.1
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• pp.273-284
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• 2004

Bayes estimation of parameters is considered for two independent exponential distributions with ordered means. Order restricted Bayes estimators for means are obtained with respect to inverted gamma, noninformative prior and uniform prior distributions, and their asymptotic properties are established. It is shown that the maximum likelihood estimator, restricted maximum likelihood estimator, unrestricted Bayes estimator, and restricted Bayes estimator of the mean are all consistent and have the same limiting distribution. These estimators are compared with the corresponding unrestricted Bayes estimators by Monte Carlo simulation.

• Journal of Environmental Science International
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• v.7 no.3
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• pp.375-382
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• 1998

The characteristics of the basic statistics and steadiness of wind and the monthly normality test of surface wind distribution are investigated by using the observed wind data compiled from 10m meteorological observation tower at Seocheon district, where is located In the western coastal region of Korea. during the period from Feb. 7, 1996 to Feb. 7 1997 The northerly is appeared to be even in August and Sepember due to the influences of loccal circulation such as land and sea breeze. The correlation coefacients between two wind components are seemed to be positive during the in the period of from June to September and negative from October to April, respectively The constancy of wand Is high In shifts to lower values Increasing sampling time. It is found from monthly normality test based on the skewness and the excess of kurtosis coefficients that the distribution of zonal wind component is normal In spring and meridional one Is normal in late summer and early autumn.

• Journal of the Institute of Convergence Signal Processing
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• v.20 no.4
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• pp.193-198
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• 2019

The wide spread of genuine and fake information on internet has lead to various studies on text analysis. Copying and pasting others' work without acknowledgement, research results manipulation without proof has been trending for a while in the era of data science. Various tools have been developed to reduce, combat and possibly eradicate plagiarism in various research fields. Text similarity measurements can be manually done by using both parametric and non parametric methods of which this study implements cosine similarity and Pearson correlation as parametric while Spearman correlation as non parametric. Cosine similarity and Pearson correlation metrics have achieved highest coefficients of similarity while Spearman shown low similarity coefficients. We recommend the use of non parametric methods in measuring text similarity due to their non normality assumption as opposed to the parametric methods which relies on normality assumptions and biasness.

• Nuclear Engineering and Technology
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• v.14 no.3
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• pp.103-109
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• 1982

An empirical formula for determining water content as functions of uranium concentration and nitric acid normalities in uranyl nitrate solutions has been derived from a least-squares analysis of experimental data, i.e., uranium concentration, nitric acid normalities and solution densities for a large number of UO$_2$(NO$_3$)$_2$ solutions. The formula derived is Q=1-0.3628C-0.0327H$^{+}$ where Q, C, and H$^{+}$ stand for water content (g/cc), uranium concentration (g/cc), ana nitric acid normality, respectively. Atom number densities and nuclear criticality for hypothetical uranyl nitrate solutions have been calculated by using the empirical formula, ana compared with the results obtained on the basis of uranium concentration, nitric acid normality, and solution density. The empirical formula derived in this study seems to be useful in uranium concentrations ranging from 0.295g/cc down to 0.004g/cc and nitric acid normality from 5.06 to 1.00..00.

• Journal of the Korean GEO-environmental Society
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• v.16 no.4
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• pp.33-40
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• 2015

In the correlation formulas related to consolidation proposed at present, the analyzed areas are limited to certain overseas or domestic areas and in order to increase the number of data, experimental data of different areas are integrated and therefore in many cases application is difficult. In addition, models have been developed without clear statistic evaluation of the obtained data. Accordingly, this study divided the soft areas of the west coast into Hangang, Kumgang and Yeongsangang in order to maximally reduce uncertainty of the experimental data and performed normality test and regression analysis on the physical and dynamic characteristics. According to the analysis result, the compression index and the modified compression index had strong linearity and in all areas modified compression index and initial void ratio had closest correlation, followed by total unit weight, water contents and liquid limits. As for overconsolidation ratio with depth, the width of overconsolidation ratio was large when the depth was less than 5 to 6 m in all areas and when the depth was over 5 to 6 m, the ratio was constant.

• Journal of Technologic Dentistry
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• v.41 no.3
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• pp.211-217
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• 2019

Purpose: The purpose of this study is to evaluate the repeated measurement stability of scans related to dentition type. Methods: A normal model and the crowding and diastema models are also duplicated using duplicating silicon. After that, a plaster model is made using a plaster-type plaster on the duplicate mold, and each model is scanned 5 times by using an extraoral scanner. The gingival part and molar part were deleted from the 3D STL file data obtained through scanning. Using the 3D stl file obtained in this way, data is nested between model groups. Thereafter, RMS values obtained were compared and evaluated. The normality test of the data was performed for the statistical application of repeated measurements with dentition type, and the normality was satisfied. Therefore, the one-way ANOVA test, which is a parametric statistical method, was applied, and post-tests were processed by the Scheffe method. Results: The average size of each RMS in the Normal, Diastema, and Crowding groups was Normal> Crowding> Diastema. However, the standard deviation was in the order of Crowding> Normal> Diastema. The average value of each data is as follows. Diastema model was the smallest ($5.51{\pm}0.55{\mu}m$), followed by the crowding model ($12.30{\pm}2.50{\mu}m$). The normal model showed the maximum error ($13.23{\pm}1.06{\mu}m$). Conclusion: There was a statistically significant difference in the repeatability of the scanning measurements according to the dentition type. Therefore, you should be more careful when scanning the normal intense or crowded dentition than scanning the interdental lining. However, this error value was within the range of applicable errors for all clinical cases.