• Communications for Statistical Applications and Methods
• /
• 제12권1호
• /
• pp.241-252
• /
• 2005

In this study we suggest that the spatial correlation structure of the brain fMRI data be used to characterize the functional connectivity of the brain. For some concussion and recovery data, we examine how the correlation structure changes from one step to another in the data analyses, which will allow us to see the effect of each analysis to the spatial correlation or the functional connectivity of the brain. This will lead us to spot the processes which cause significant changes in the spatial correlation structure of the brain. We discuss whether or not we can decompose correlation matrices in terms of its causes of variations in the data.

• Communications for Statistical Applications and Methods
• /
• 제29권6호
• /
• pp.655-664
• /
• 2022

On the motivation by an integrative study of multi-omics data, we are interested in estimating the structure of the sparse cross correlation matrix of two high-dimensional random vectors. We rewrite the problem as a multiple testing problem and propose a new method to estimate the sparse structure of the cross correlation matrix. To do so, we test the correlation coefficients simultaneously and threshold the correlation coefficients by controlling FRD at a predetermined level α. Further, we apply the proposed method and an alternative adaptive thresholding procedure by Cai and Liu (2016) to the integrative analysis of the protein expression data (X) and the mRNA expression data (Y) in TCGA breast cancer cohort. By varying the FDR level α, we show that the new procedure is consistently more efficient in estimating the sparse structure of cross correlation matrix than the alternative one.

• 국제물리치료학회지
• /
• 제2권2호
• /
• pp.294-300
• /
• 2011

The purpose of this study was to investigate the influence of the static pelvic inclination and declination in the static standing position on weight bearing rate and gait elements. Fourteen healthy adults in their twenties were participated. Two groups of healthy adults were allocated in this study: above and below the average of pelvic tilt. The correlation between the pelvic inclination, weight bearing rate and gait elements were measured. There was a statistical correlation between the pelvic tilt and step. Also, there was a statistical difference when we compared anterior declination with swing period and posterior declination with step. There was an asymmetric correlation between pelvic tilt and step. However, there was no statistical difference between the groups above and below the average of pelvic tilt. This result indicates that dipper pelvic inclination doesn't affect the asymmetry of step.

• 대한인간공학회지
• /
• 제5권1호
• /
• pp.43-48
• /
• 1986

This study aims to investigate the effect of biorhythm to work performance. In order to do this, the data are collected from the manufacturing factory which produce a sportware, and the statistical test are made to testify the relationship between the number of defective items and the biorhythm chart of the workers. The number of defective items which made in the peak day, usual day, and critical day on the worker's biorythm chart are compared with each other, and the statistical test are made to see if there are difference between them, and the correlation analysis are made to see if there is any correlation between the work performance and the biorhythm chart. The result of the statistical test shows that the biorythm of the worker gives an effect to his work performance with a correlation.

• 품질경영학회지
• /
• 제18권1호
• /
• pp.84-95
• /
• 1990

The objective of this study is to understand the effect of measurement-related investment. That is, this study aims at verifying the correlation between the measurement-related investment and inferiority rate of products by statistical analysis. The samples of this study are 376 industrial companies in Korea, and the research data was analysed on inferiority state of industrial companies with a measurement standard laboratory. The analysis was made by the elementary statistics, the correlation analysis and the regression analysis. The results are summarized as follows : First, the inferioriy rate of the industrial companies with a measurement standard laboratory was relatively lower than that of the other companies without the laboratory by statistical significance. Second, the increment on measurement-related investment had a negative correlation with the increment of inferiority rate, and the increase of measurement-related investment showed decrease of the inferiority rate by regression analysis.

• Journal of the Optical Society of Korea
• /
• 제12권3호
• /
• pp.170-173
• /
• 2008

In this study, we simulated a statistical model of FCS(fluorescence correlation spectroscopy) based on a Poisson process to understand and explain observations of the experiment performed on molecules of ultra-low concentration by the home-built laser-scanning confocal microscope. The statistical model confirmed that the relative mean square amplitude of fluctuations is shown to be inversely proportional to the average number of molecules, even in the ultra-low concentration, if some conditions are satisfied. Signal-to-noise ratio and the variability of dwelling time under the confocal volume were found to be effective conditions for the experiment.

• 대한안전경영과학회지
• /
• 제11권3호
• /
• pp.41-48
• /
• 2009

The risk assessment for heavy metal pollutions were analyzed by using statistical techniques including correlation and cluster analyses. The contamination data in this investigation obtained were from the Chungcheongnam-do abandoned mines. The descriptive statistical analysis showed that the values of Pb and Zn were relatively higher than other heavy metal values. The detection of heavy metals by distance from abandoned mines within 1,000m were mostly As, Cd, Pb, and Zn. It was noted, especially, that Zn was even detected at 4,000m The results of coefficient correlation showed that Zn to Cd was the highest values. The cluster and dendogram analyses were generated. The results showed the two clear groups by heavy metal characteristics.

• ETRI Journal
• /
• 제43권1호
• /
• pp.31-39
• /
• 2021

One of the major challenges in wireless body area networks (WBANs) is sensor fault detection. This paper reports a method for the precise identification of faulty sensors, which should help users identify true medical conditions and reduce the rate of false alarms, thereby improving the quality of services offered by WBANs. The proposed sensor fault detection (SFD) algorithm is based on Pearson correlation coefficients and simple statistical methods. The proposed method identifies strongly correlated parameters using Pearson correlation coefficients, and the proposed SFD algorithm detects faulty sensors. We validated the proposed SFD algorithm using two datasets from the Multiparameter Intelligent Monitoring in Intensive Care database and compared the results to those of existing methods. The time complexity of the proposed algorithm was also compared to that of existing methods. The proposed algorithm achieved high detection rates and low false alarm rates with accuracies of 97.23% and 93.99% for Dataset 1 and Dataset 2, respectively.

• Journal of the Korean Statistical Society
• /
• 제35권2호
• /
• pp.143-156
• /
• 2006

In the present paper, various solutions for generalized canonical correlation analysis (GCCA) are considered depending on the criteria and constraints. For the comparisons of some characteristics of the solutions, we provide with certain unifying stationary equations which might to also useful to obtain various generalized canonical correlation analysis solutions. In addition, we suggest an approach for the generalized canonical correlation analysis by exploiting the concept of maximum eccentricity originally de-signed to test the internal independence structure. The solutions, including new one, are compared through unifying stationary equations and by using some numerical illustrations. A type of iterative procedure for the GCCA solutions is suggested and some numerical examples are provided to illustrate several GCCA methods.

• Communications for Statistical Applications and Methods
• /
• 제21권4호
• /
• pp.335-347
• /
• 2014

This paper employs dynamic conditional correlation (DCC) model to examine time-varying comovement in the Korean stock market with a focus on the financial industry. Analyzing the daily returns of KOSPI 200 eight sector indices from January 2008 to December 2013, we find that stock market correlations significantly increased during the GFC period. The Financial Sector had the highest correlation between the Constructions-Machinery Sector; however, the Consumer Discretionary and Consumer Staples sectors indicated a relatively lower correlation between the Financial Sector. In terms of model fitting, the DCC with t distribution model concludes as the best among the four alternatives based on BIC, and the estimated shape parameter of t distribution is less than 10, implicating a strong tail dependence between the sectors. We report little asymmetric effect in correlation dynamics between sectors; however, we find strong asymmetric effect in volatility dynamics for each sector return.