• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.5
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• pp.331-340
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• 2016

It is important to select proper ground motions for obtaining accurate results from response history analyses. The purpose of this study is to propose an accurate and efficient method that does not require excessive computation for selecting and scaling ground motions to match target response spectrum mean and variance. The proposed method is conceptually simple and straightforward, and it does not use a simulation algorithm that requires a sophisticated subroutine program. In this method, the desired number of ground motions are sequentially scaled and selected from a ground motion library. The proposed method gives the best selection results using Sum of Square Error and has the smallest value(=0.14). Also, The accuracy and consistency of the proposed method are verified by comparing the selection results of the proposed method with those of existing methods.

• Journal of Korean Academy of Nursing
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• v.49 no.3
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• pp.307-316
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• 2019

Purpose: This study was conducted to investigate the influence of emotional expressivity, emotional intelligence, affectivity, job autonomy, social support, and emotional labor on clinical nurses' individual well-being and to provide guidelines for interventions and strategies for its improvement. Methods: The sample consisted of 207 nurses recruited from a general hospital in Korea. The participants completed a structured self-report questionnaire comprising measures of emotional expressivity, emotional intelligence, positive affectivity, negative affectivity, job autonomy, supervisor support, coworker support, deep acting, surface acting, emotional exhaustion, and job satisfaction. Data were analyzed using SPSS statistics 22.0 and AMOS 22.0. Results: The final model was a good fit for the data based on the model fit indices. In the path analysis, surface acting, negative affectivity, supervisor support, and coworker support had statistically significant effects on emotional exhaustion, explaining 29.0% of the variance. Deep acting, emotional exhaustion, positive affectivity, and emotional intelligence had statistically significant effects on job satisfaction, explaining 43.0% of the variance. Conclusion: Effective strategies to improve clinical nurses' individual well-being should focus on surface acting, deep acting, affectivity, social support, and emotional intelligence. The results of this study can be utilized as base data to manage emotional labor and improve clinical nurses' individual well-being.

• The Journal of the Acoustical Society of Korea
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• v.20 no.7
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• pp.94-100
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• 2001

When using a sample covariance matrix data in paucity of snapshots, adaptive matched field processing will have problem in inverting covariance matrix due to the rank deficiency. The general solutions are diagonal loading and eigenanalysis methods, but there is a significant bias in the power output. This paper presents a quantitative study of bias of power output and the performance of source localization through the simulation and the measured data analysis in fixed source case using the diagonal loading method for the minimum variance processor. Results show that the bias in power output is reduced and the performance of source localization is improved when the number of snapshots is greater than the number of array sensors.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.394-397
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• 2003

In this paper, we have proposed a clock recovery algorithm of OFDM/QPSK-DMR(Orthogonal Frequency Division Multiplexing/Quadrature Phase Shift Keying Modulation-Digital Microwave Radio)system using BL-PSF(Band Limited-Pulse Shaping Filter) and have analyzed the clock phase error variance performance of OFDM/QPSK and single carrier DMR systems. The existing OFDM/QPSK-DMR system using the windowing requires training sequence or CP(Cyclic Prefix) to synchronize a receiver clock frequency Because there is no training sequence or CP(Cyclic prefix) in our proposed DMR system, the proposed clock recovery algorithm is useful to the OFDM/QPSK-DMR system using BL-PSF, The simulation results confirm that the proposed clock recovery algorithm has the same clock phase error variance performance in a single carrier DMR system under AWGN(Additive White Gaussian Noise) environment.

• Korean Journal of Adult Nursing
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• v.28 no.6
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• pp.680-690
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• 2016

Purpose: This study was designed to identify knowledge, attitude, environment, and self-efficacy among perioperative nurses in terms of radiation protection and to describe those factors affecting radiation protection behaviors. Methods: The sample was comprised of 128 perioperative nurses who agreed to participate in this descriptive study. Data were collected from a self-administered questionnaire and were analyzed using the t-test, analysis of variance, Mann-whitney U test, Kruskal-Wallis test, Pearson's correlation, and multiple regression analyses. Results: Radiation protection behaviors were significantly different by participant's gender, length of career as a perioperative nurse, educational level and prior experience with radiation protection education. Radiation protection behaviors were significantly correlated with radiation protection environment and self-efficacy in terms of radiation protection behaviors. In the multiple linear regression models, radiation protection environment and self-efficacy on radiation protection behaviors were statistically significant predictors of radiation protection behaviors, which accounted for 50.3% of variance in dependent variable. Conclusion: This study concluded that radiation protective environment in operating room is important to promote radiation protective behaviors and radiation safety management program to enhance self-efficacy is highly recommended.

• Journal of Communications and Networks
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• v.17 no.4
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• pp.419-427
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• 2015

There have been increases in the elderly population worldwide, and this has been accompanied by rapid growth in the health-care market, as there is an ongoing need to monitor the health of individuals. Wireless body area networks (WBANs) consist of wireless sensors attached on or inside the human body to monitor vital health-related problems, e.g., electrocardiograms (ECGs), electroencephalograms (EEGs), and electronystagmograms (ENGs). With WBANs, patients' vital signs are recorded by each sensor and sent to a coordinator. However, because of obstructions by the human body, sensors cannot always send the data to the coordinator, requiring them to transmit at higher power. Therefore, we need to consider the lifetime of the sensors given their required transmit power. In the IEEE 802.15.6 standard, the transmission topology functions as a one-hop star plus one topology. In order to obtain a high throughput, we reduce the transmit power of the sensors and maintain equity for all sensors. We propose the multiple-hop transmission for WBANs based on the IEEE 802.15.6 carrier-sense multiple-access with collision avoidance (CSMA/CA) protocol. We calculate the throughput and variance of the transmit power by performing simulations, and we discuss the results obtained using the proposed theorems.

• The Journal of Industrial Distribution & Business
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• v.8 no.1
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• pp.5-13
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• 2017

Purpose - In this article, a dynamic model like a VAR is an appropriate choice for estimating the possible interrelationship between ownership structure and firm performance as a dynamic process. Research design, data, and methodology - Data of this work are collected from Chinese stock exchange including 350 Chinese-listed firms during the period of 1999-2012. We hypothesize that this interrelationship dynamically exists between ownership structure and firm performance. To examine the correlation, a panel Vector Auto-regression (PVAR) approach generated by GMM method is utilized to test the possible dynamic relation embedded in corporate governance. Another two dynamic analysis solutions such as orthogonalized impulse-response function and variance decomposition are also used simultaneously. Results - Findings of this study indicate the evidence that dynamically endogenous relationship exists between ownership structure and firm performance. Further, there is a dynamical correlation between investment and performance. Impulse response and variance decomposition illustrate that impact of a shock to variables themselves is the main source for their variability. Conclusions - The conclusion in this study is that there is a bidirectional and inter-temporal effect between proportion of ownership and corporate performance for a long run in accordance with impulse response function. Overall, our results suggest that corporate governance in China is more market oriented.

• Journal of Korean Academy of Nursing Administration
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• v.19 no.5
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• pp.578-588
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• 2013

Purpose: The purpose of this study was to identify the effects of bullying, negative affectivity and burnout in the nurses. Methods: The sample consisted of 389 nurses. Data were analyzed using frequency, percentage, mean, standard deviation, t-test, ANOVA, Scheff$\acute{e}$, Pearson Correlation Analysis and Hierarchical Multiple Regression. Results: The control variables of age, marital status, education level, current position, health status and work unit explained 30.2%(F=28.9, p<.001) of variance in burnout. The control variables, bullying and negative affectivity collectively explained 49.7% of variance in burnout. Conclusion: The results indicate that the demographic factors influencing burnout are age, education level, health status, work unit, while bullying and negative affectivity in the work places are factors that influence burnout. These findings can be utilized to develop strategies to reduce bullying and negative affectivity.

• Research in Community and Public Health Nursing
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• v.25 no.4
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• pp.282-290
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• 2014

Purpose: The purpose of this study was to compare health promoting behavior between working and non-working mothers with infants and toddlers, and to investigate factors affecting the mothers'health promoting behavior. Methods: This descriptive study was conducted through conveniently sampled 403 women who visited the child health clinics at two public health centers. The questionnaire included the Health Promoting Life Style Profile (HPLP) and a visual analogue scale for subjective health status. ANCOVA, one-way ANOVA, correlation analysis, and stepwise multiple regression were conducted using SPSS ver. 21. Results: Working mothers' average HPLP score ($2.30{\pm}0.37$) was higher than non-working mother's ($2.15{\pm}0.37$). The score of the physical activity subscale was lowest among the subscales and there was a difference between the two groups. Subjective mental health status was the only predictor of working mothers'health promoting behavior, and it explained 23.2% of variance in health promoting behavior. Subjective mental health status, education, and age were the predictors of non-working mothers' health promoting behavior and they explained 27.2% of variance in health promoting behavior. Conclusion: According to the findings, both working and non-working mothers' health promoting behaviors were low. To promote mothers' health, it is necessary to develop diverse community health promotion programs to support mothers.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.855-862
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• 1998

This paper investigates the impact of the forecast error on performance of a reservoir system for hydropower production. Forecast error is measured as th Root Mean Square Error (RMSE) and parametrically varied within a Generalized Maintenance Of Variance Extension (GMOVE) procedure. A set of transition probabilities are calculated as a function of the RMSE of the GMOVE procedure and then incorporated into a Bayesian Stochastic Dynamic Programming model which derives monthly operating policies and assesses their performance. As a case study, the proposed methodology is applied to the Skagit Hydropower System (SHS) in Washington state. The results show that the system performance is a nonlinear function of RMSE and therefor suggested that continued improvements in the current forecast accuracy correspond to gradually greater increase in performance of the SHS.