• Communications for Statistical Applications and Methods
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• v.28 no.3
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• pp.295-305
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• 2021

Most graphical representation methods for two-dimensional contingency tables are based on the frequencies, probabilities, association measures, and goodness-of-fit statistics. In this work, a method is proposed to represent the correlation coefficients for each of the two selected levels of the row and column variables. Using the correlation coefficients, one can obtain the vector-matrix that represents the angle corresponding to each cell. Thus, these vectors are represented as a unit circle with angles. This is called a CC plot, which is a correlation plot for a contingency table. When the CC plot is used with other graphical methods as well as statistical models, more advanced analyses including the relationship among the cells of the row or column variables could be derived.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2510-2518
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• 2022

The main purpose of collecting and analyzing operating experience events is to look for insights to improve safety. The underlying assumption is the correlation and causality between events with different safety significances. The analysis of this assumption could be valuable to optimize operating experience feedback programs and to enhance safety. This paper analyses the correlation between events with different safety significances. Groups of events from six nuclear energy related databases are considered. The findings are that a correlation exists but with various levels and not as large or consistent as might be expected across different databases. These results might be the basis for further work to analysis causality, to find out how a similarity in causes influences the correlation, and finally to improve the operating experience program.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.1882-1885
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• 2002

This paper shows design of maximal-period sequences with prescribed constant auto-correlation values based on one-dimensional (1-D) maps with (mite bits. We construct such 1-D maps based on piecewise linear onto chaotic maps. Theoretical analyses and some design examples are given.

• Korean Journal of Remote Sensing
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• v.6 no.2
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• pp.153-164
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• 1990

A statistical correlation between cloud thickness and brightness is shown by regression analysis using the least-square method. Cloud thicknesses are obtained from radiosonde observation. Brightness values are obtained from GMS visible channel. Regression analyses are preformed on both thickness data used in conjunction with brightness data for summer season. The results are shown by the regression curve relating thickness and brightness accounting for 79% of variance. And the relationship between thickness and precipitable water in the cloud layers is analyzed. The thickness shows a positive correlation with precipitable water in cloudy layers.

• Korean Journal of Human Ecology
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• v.21 no.2
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• pp.257-267
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• 2012

The purpose of this study was to observe work-related emotional consequences in call center employees. The data were collected from 434 employees in 3 call centers by way of a self-administered questionnaire. Frequencies, Cronbach's alpha, T-test, one-way ANOVA, Pearson's correlation analysis, and multiple regression analyses were conducted by SPSS Win 18.0. The results of this study were as follows: first, job burnout proved to be significant, and demonstrated a positively correlation to surface acting and negatively correlation to deep acting. Second, altruism proved to be significant and demonstrated a positive correlation to deep acting, while also demonstrating a negatively correlation to both sex and surface acting. Third, conscientiousness proved to be significant and demonstrated a positive correlation to both age and deep acting, as well as a negatively correlation to surface acting. Finally, work-family conflict proved to be significant and demonstrated a positive correlation to both sex and workload in terms of hours per day.

• School Mathematics
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• v.6 no.3
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• pp.251-266
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• 2004

The purpose of this study is to analyze the concept of correlation in statistics, secondary mathematics textbooks, foreign mathematics textbooks in point of didactic transposition theory. It is investigated that the relevance and alternative ways of introducing correlation concept without correlation coefficient. In addition, we compare five Korean secondary textbooks and find out characteristics on didactic transposition of correlation. We end pedagogical implications of the analyses presented and general conclusions concerning the didactic transposition of correlation.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.6
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• pp.650-662
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• 2011

The statistical tools such as empirical orthogonal function (EOF), and singular value decomposition (SVD) have been applied to analyze the characteristic of air pollutant over southeast Asia as well as to evaluate Zimeke's tropospheric column ozone (ZTO) determined by tropospheric residual method. In this study, we found that the EOF and SVD analyses are useful methods to extract the most significant temporal and spatial pattern from enormous amounts of satellite data. The EOF analyses with OMI $NO_2$ and OMI HCHO over southeast Asia revealed that the spatial pattern showed high correlation with fire count (r=0.8) and the EOF analysis of CO (r=0.7). This suggests that biomass burning influences a major seasonal variability on $NO_2$ and HCHO over this region. The EOF analysis of ZTO has indicated that the location of maximum ZTO was considerably shifted westward from the location of maximum of fire count and maximum month of ZTO occurred a month later than maximum month (March) of $NO_2$, HCHO and CO. For further analyses, we have performed the SVD analyses between ZTO and ozone precursor to examine their correlation and to check temporal and spatial consistency between two variables. The spatial pattern of ZTO showed latitudinal gradient that could result from latitudinal gradient of stratospheric ozone and temporal maximum of ZTO in March appears to be associated with stratospheric ozone variability that shows maximum in March. These results suggest that there are some sources of error in the tropospheric residual method associated with cloud height error, low efficiency of tropospheric ozone, and low accuracy in lower stratospheric ozone.

• Economic and Environmental Geology
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• v.22 no.2
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• pp.141-150
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• 1989

In order to make economic and geological evaluation of coal in Korea, proximate and ultimate analyses were carried out as well as coal petrological studies such as maceral analyses, vitrinite reflectance and sporinite fluorescence measurement. The coeffcient of correlation between each factor of both conventional utilization and coal petrological parameters were studied as in Table 5 and 6. Their conclusions were as follow: (1) for anthracite, the good parameters of coal rank are mean vitrinite reflectance, carbon content, hydrogen content and H/C atomic ratio: (2) for brown coal and sub-bituminous coal, the good parameters of coal rank are carbon content, calorific value, moisture content, hydrogen content, oxygen content and O/C atomic ratio as well as vitrinite reflectance and sporinite fluorescence. An attempt is made to infer the coalforming environment by utilization of coal petrological analyses and to make comparison of coal analyses with proximate and ultimate analyses throughout the island arc region including Japan, Philippine and Indonesia and continental region including USA, Canada and Australia. As a result, meceral composition of Paleozoic and Mesozoic anthracite are similar to that of the Paleozoic continental coals, which were formed under dry conditions or low water table, but the coalification degree suddenly increased during Daebo orogeny (middle Jurassic to lower Cretaceous). The Tertiary coal resembles those of Tertiary island arc region coal characterized by higher calorific value, volatile matter content and H/C atomic ratio and by the formation of coal under wet conditions or higher water table.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.2
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• pp.55.3-55.3
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• 2015

We study the possibility of new approach for identifying instrumental noise artifacts and sources of gravitational wave (GW) data such as LIGO and CLIO using various correlation analyses.To improve the quality of data for the GW signal search, the instrumental noises should be reduced in an appropriate way. Furthermore, it is important to understand the correlation between auxiliary channels of the GW detector. In this study, we investigate the possible way of identifying glitch triggers by generating time-frequency-correlation (TFC) maps between the related channels and compare the result to the current conventional schemes.

• Transactions of Materials Processing
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• v.20 no.2
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• pp.124-131
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• 2011

A flexible stretch forming process is useful for small quantity batch production because various shape changes of the flexible die can be achieved conveniently. In this study, the design variables, namely, the punch size, curvature radius and elastic pad thickness, were quantitatively evaluated to understand their influence on sheet formability using statistical methods such as the correlation and regression analyses. Forming simulations were designed and conducted by a three-way factorial design to obtain numerical values of a shape error. Linear relationships between the design variables and the shape error resulted from the Pearson correlation analysis. Subsequently, a regression analysis was also conducted between the design variables and the shape error. A regression equation was derived and used in the flexible die design stage to estimate the shape error.