• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권1호
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• pp.141-156
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• 2011

In this paper we develop a link cost function for data delivery in sensor network. Usually most conventional methods determine the optimal coefficients in the cost function without considering the surrounding environment of the node such as the wireless propagation environment or the topological environment. Due to this reason, there are limitations to improve the quality of data delivery such as data delivery ratio and delay of data delivery. To solve this problem, we derive a new cost function using the concept of Partially Connected Neural Network (PCNN) which is modeled according to the input types whether inputs are correlated or uncorrelated. The correlated inputs are connected to the hidden layer of the PCNN in a coupled fashion but the uncoupled inputs are in an uncoupled fashion. We also propose the training technique for finding an optimal weight vector in the link cost function. The link cost function is trained to the direction that the packet transmission success ratio of each node maximizes. In the experimental section, we show that our method outperforms other conventional methods in terms of the quality of data delivery and the energy efficiency.

• Communications for Statistical Applications and Methods
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• 제5권2호
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• pp.373-381
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• 1998

In this paper a new control chart which accounts for correlation between process subgroups will be proposed. We consider the case where the process fluctuations are autocorrelated by a stationary AR(1) time series and where n($\geq1$) items are sampled from the process at each sampling time. A simulation study is presented and shows that for correlated subgroups, the proposed control chart makes a significant improvement over the traditionally employed X-bar chart which ignores subgroup correlations. Finally, we illustrate the proposed chart by comparing the standardized residuals and X-bar chart on a data set of motor shaft diameters.

• 한국경영과학회지
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• 제28권3호
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• pp.61-66
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• 2003

In many multiple regression analyses, the “multi-collinearity” problem arises since some independent variables are highly correlated with each other. Practically, the Ridge regression method is often adopted to deal with the problems resulting from multi-collinearity. We propose a better alternative method using iteration to obtain an exact least squares estimator. We prove the solvability of the proposed algorithm mathematically and then compare our method with the traditional one.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2006년도 PROCEEDINGS OF JOINT CONFERENCEOF KDISS AND KDAS
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• pp.171-179
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• 2006

For the problem of variable selection in linear models, we consider the errors are correlated with V covariance matrix. Hocking's theorems on the effects of the overfitting and the underfitting in linear model are extended to the less than full rank and correlated error model, and to the ANCOVA model.

• 제어로봇시스템학회논문지
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• 제14권1호
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• pp.70-74
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• 2008

In the field of camera motion research, it is widely held that the position (movement) and pose (rotation) of cameras are correlated and cannot be independently separated. A new equation based on inner product is proposed here to independently separate the position and pose. It is proved that the position and pose are not correlated and the equation is applied to estimation of the camera exterior parameters using a real image and 3D data.

• 산업공학
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• 제5권1호
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• pp.61-74
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• 1992

Recognizing the lack of empirical studies on the returns to R & D investment in Korean firms, this paper analyzes the relationships between R & D investment and corporate performances measured by sales growth rate, profit rate and PER. The data used here are from 167 firms in 8 different industries covering the period from 1985 to 1989. The results show that the profit rate is strongly correlated with R & D investment. But unlike the results of most studies previously done in the U.S., R & D investment only weakly and insignificantly correlated with sales growth and PER.

• Communications for Statistical Applications and Methods
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• 제6권3호
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• pp.755-760
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• 1999

In multivariate stratified sampling surveys it is general to use a few stratification variables which are highly correlated with the important variables at design stage. But there might be some secondary study variables which are not so highly correlated with those stratification variables. In that case it is not efficient to use the same type of estimator due to the secondary variables as the one base on the important variables. A post-stratified estimation is proposed to increase the efficiency of the estimator with existence of secondary variables. The proposed method is illustrated with a set of fishery household population survey data.

• 대한영양사협회학술지
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• 제5권1호
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• pp.29-47
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• 1999

The purpose of this study is to provide the basic data and their analysis to improve hospital foodservice by identifying patient satisfaction with different attributes of hospital foodservice and its influencing factors using self written survey on nine hundred fifteen hospitalized patients in 28 general hospitals in Seoul and Kungki area. The statistical analysis of data was done by SAS/WIN package(Version 6.11) to determine Descriptive Analysis, T-test, Analysis of Variance, Pearson's Correlation, and Factor Analysis. The summary of the study results is as follows : 1. Among sixteen food-service quality attributes, the most unsatisfying one was the meal itself, the provision of nutrition informations, the possibility of menu choices, immediate response on meal problems, and the taste of the meal. 2. There was a positive correlation between the general quality satisfaction and freshness, nutritional considerations, and the temperature of the dishes and trays, and variety of menu in food-service quality were also correlated positively. 3. Based on the result of statistical analysis on the expectation and recognition in hospital food-service quality attributes vs quality satisfaction, expectation was negatively correlated with quality satisfaction : however, recognition was positively correlated.

• 한국보건간호학회지
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• 제34권1호
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• pp.22-34
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• 2020

Purpose: This study aimed to identify the effects of adolescent sexual media literacy and sexual permissiveness on gender sensitivity and to provide evidences useful in developing a sex education program that would promote gender sensitivity among adolescents. Methods: Data were derived from 250 adolescents' responses to questionnaires. Collected data were analyzed using ANOVA, Pearson's correlation coefficient, and multiple regression. Results: Gender sensitivity according to gender was significantly different (t=-6.54, p=0.001). Gender sensitivity was positively correlated with sexual media literacy (r=0.36, p<0.001), and negatively correlated with sexual permissiveness (r=.22, p<.001). Sexual media literacy was negatively correlated with sexual permissiveness (r=-0.39, p<0.001). The variables affecting the participants' gender sensitivity on media literacy were gender (β=0.33, p<0.001) and sexual depiction scene (β=0.24, p<0.001). Conclusion: Gender and sexual media literacy influenced participants' gender sensitivity. Therefore, when developing a school-based sex education program, sexual media literacy should be included as a key concept; moreover, gender-specific programs need to be developed. Furthermore, teaching methods should enhance media literacy related to sexual depiction scenes and promote safe and healthy sexual permissiveness.

• 한국물환경학회지
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• 제34권2호
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• pp.202-209
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• 2018

The purpose of this study was to analyze the correlation between the effluent of a sewage treatment plant (STP) and the adjacent stream located downstream of the STP in Nakdong River. Flow and water quality data, such as BOD, COD, SS, T-N, and T-P data, for 12 STPs and adjacent downstream monitoring stations in the main stream and tributaries of Nakdong River were collected from 2012 to 2015. As a result of correlation analysis between river flow and water quality at the river water quality measurement point, COD, SS, and T-P were correlated positively with the river flow rate at 6, 8, and 6 points, respectively. As a result of analyzing the water quality of sewage treatment plant effluents and downstream streams, BOD and COD were correlated at 2 and 3 points, respectively. T-N showed a positive correlation at 9 points, and 7 of them had a strong positive correlation, indicating that sewage treatment effluent had a large effect on downstream streams. In this study, we found that the correlation between the river flow rate and the water quality factors (COD, SS, TP) was high at river water measurement points, and the sewage treatment plant effluent was correlated with the T-N value of adjacent streams.