• Journal of the Korean Data and Information Science Society
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• v.12 no.1
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• pp.127-133
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• 2001

In this article we establish multivariate cumulative sum (CUSUM) control charts based on residual vector with correlated observations. We first find the residual vector and its expectation and variance-covariance matrix and then evaluate the average run length (ARL) of the control charts.

• Communications for Statistical Applications and Methods
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• v.9 no.1
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• pp.115-128
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• 2002

Hierarchical models are widely used for inference on correlated parameters as a compromise between underfitting and overfilling problems. In this paper, we take a Bayesian approach to analyzing hierarchical models and suggest a Markov chain Monte Carlo methods to get around computational difficulties in Bayesian analysis of the hierarchical models. We apply the method to a real data on smoking and lung cancer which are collected from cities in China.

• Journal of the Korean Statistical Society
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• v.29 no.2
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• pp.231-245
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• 2000

This paper considers a linear regression model with space and time data in where the disturbances follow spatially correlated error components. We provide the best linear unbiased predictor for the one way error components. We provide the best linear unbiased predictor for the one way error component model with spatial autocorrelation. Further, we derive two diagnostic test statistics for the assessment of model specification due to spatial dependence and random effects as an application of the Lagrange Multiplier principle.

• International journal of advanced smart convergence
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• v.10 no.1
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• pp.75-81
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• 2021

As the number of connected smart devices and applications increases explosively, the existing orthogonal multiple access (OMA) techniques have become insufficient to accommodate mobile traffic, such as artificial intelligence (AI) and the internet of things (IoT). Fortunately, non-orthogonal multiple access (NOMA) in the fifth generation (5G) mobile networks has been regarded as a promising solution, owing to increased spectral efficiency and massive connectivity. In this paper, we investigate the achievable data rate for non-orthogonal multiple access (NOMA) with negatively-correlated information sources (CIS). For this, based on the linear transformation of independent random variables (RV), we derive the closed-form expressions for the achievable data rates of NOMA with negatively-CIS. Then it is shown that the achievable data rate of the negatively-CIS NOMA increases for the stronger channel user, whereas the achievable data rate of the negatively-CIS NOMA decreases for the weaker channel user, compared to that of the positively-CIS NOMA for the stronger or weaker channel users, respectively. We also show that the sum rate of the negatively-CIS NOMA is larger than that of the positively-CIS NOMA. As a result, the negatively-CIS could be more efficient than the positively-CIS, when we transmit CIS over 5G NOMA networks.

• Communications for Statistical Applications and Methods
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• v.6 no.3
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• pp.667-676
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• 1999

We investigate the effects of omission of initial observations in each individuals in the panel data regression model when the disturbances follow a serially correlated one way error components. We show that the first transformed observation can have a relative large hat matrix diagonal component and a large influence on parameter estimates when the correlation coefficient is large in absolute value.

• Journal of Labour Economics
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• v.22 no.2
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• pp.243-262
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• 1999

This paper demonstrates both theoretically and empirically that there are industry-specific factors as well as the cyclical ones that affect quit and layoff incidences and that the industry-specific effects are positively correlated between the two incidences across industries while the cyclical effects are negatively correlated over time. We first set up a theoretical model to analyze how its parameters affect quits and layoffs through the corresponding change in the optimal wage for the employer and the worker, and then derive from the theoretical separation behaviors the two testable hypotheses - that quits and layoffs are positively correlated to each other across industries, and that quits move procyclically while layoffs move countercyclically. We analyze the two sets of data, BLS establishment data on turnover rates and PSID, to empirically test and confirm each of the two hypotheses.

• The Journal of Korean Academic Society of Nursing Education
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• v.20 no.4
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• pp.471-481
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• 2014

Purpose: This study investigates the relationship among stress, Yangsaeng and subjective happiness in female undergraduate nursing students in the Republic of Korea. Method: The subjects of this study were 283 female undergraduate nursing students in Korea. Data were collected using a self-reporting questionnaire. Data analysis included descriptive statistics, Pearson's correlation coefficients, independent t-tests, one-way ANOVA, Scheffe test, Stepwise multiple regression and Cronbach's ${\alpha}$. Results: Yangsaeng negatively correlated with stress (r=-.299, p<.001) but positively correlated with subjective happiness (r=.440, p<.001). Stress negatively correlated with subjective happiness (r=-.238, p<.001). Stepwise multiple regression revealed that Yangsaeng and satisfaction with the field of nursing explained 25.4% of subjective happiness. Conclusion: The Yangsaeng oriental health care regimen could lower stress and heighten subjective happiness. Therefore, Yangsaeng could be recommended as a feasible means of promoting health and subjective happiness.

• Korean Journal of Human Ecology
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• v.15 no.1
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• pp.45-53
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• 2006

The goal of this study is to examine the relationship between efficacy belief and role performance of childcare teachers, and also to utilize the results as the basic data for teacher education. The subjects were 205 teachers at 48 childcare centers located in Jeonlabuk-do area. The instruments employed included efficacy belief, teachers' role performance, experiences, and age. The data were analyzed by t-test, Pearson correlation, and Regression Analysis. The results of this study are as follows: First, the role of child carer was the vest performance through childcare teachers' role. Second, the role of instructor, counselor, researcher, and others was significantly different among the types of childcare institution. Third, the social position of ability and personal teaching efficacy belief were correlated positively with teachers' experience. The activeness, the social position of ability, general teaching efficacy belief, personal teaching efficacy belief, and the role of child carer, instructor, counselor, researcher, and others were correlated positively with teachers' age. Fourth, the role of child carer, instructor, counselor, researcher, and others was correlated positively with the activeness and the social position of ability, whereas it was correlated negatively with failure anxiety. Lastly, the activeness was the most powerful variable influencing teachers' role performance.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.3
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• pp.69-80
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• 2011

The purpose of this study was to clothing behavior according to the self-esteem, body cathexis in multicultural familie adolescents. The data was collected by using questionnaire survey based on pre-tests, and main survey conducted in Seoul, Gyeonggi province and Chungcheong province. The 236 participants came from 135 multicultural families and 101 Korean Self-esteem, body cathexis, clothing behavior were examined through 5-point likert scale. 3 factors including clothing interest, social approval and clothing conformity were used as clothing behavior. The analysis of the collected data was conducted by using SPSS 18.0. The results of this study is as follows: First, multi-cultural family adolescent showed higher self-esteem, body cathexis, than Korean family adolescent. Second, self-esteem were positively correlated, with body cathexis in both multi-cultural family and Korean family adolescent. Third, in multi-cultural family adolescent, body cathexis were positively correlated with clothing interest, social approval and clothing conformity. In Korean family adolescent, body cathexis were positively correlated with social approval and body cathexis were negatively correlated with clothing conformity.

• Korean Journal of Occupational Health Nursing
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• v.17 no.2
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• pp.250-259
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• 2008

Purpose: The purpose of this study was to identify the relation of Job Stress, Heart Rate Variability, Blood Pressure and Lifestyle on White-Collar Workers. Method: Data were collected from August to December in 2007. HRV was measured using Freeze-Framer. WSRI and Lifestyle data were collected from the self-reported questionnaire. Result: 1) Total score of WSRI was 32.88, H score was 47.92, L score was 16.90, systolic blood pressure was 138.88mmHg, diastolic blood pressure was 81.20 mmHg. 2) WSRI correlated with L score of HRV, BP, smoking, drinking positively. WSRI correlated with H score, exercise times negatively. H correlated with exercise positively and had negative correlation with BP and L. Systolic pressure correlated with smoking and drinking positively. Conclusion: WSRI, HRV, BP and lifestyle are interrelated strongly and they need to be monitor continually. It is considered that education of health and intervention with HRV make white-collar workers concern more about their health and care.