• 전기학회논문지
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• 제60권10호
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• pp.1823-1831
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• 2011

When the RPS(Renewable Portfolio Standards) becomes effective in 2012, the use of renewable energy will be dramatically increased. However, there are no production simulations and demand supply programs that reflect the characteristics of the renewable energy. This paper analyzes correlations of the domestic wind power and solar power generation pattern in different areas and those of these sources' output and load pattern. Based on the regional correlation analysis, an appropriate method that uses a average output of the renewable energy or another modeling that takes account of uncertainty could be selected. Because it's output is dependent on weather condition, we can not control the generation of renewable energy, that is the reason why the correlation between the load and output pattern of sources can be helpful to determine whether the renewable energy is modeled as a generator or load modifier. Through this analysis, a basis will be provided in order to properly model the renewable energy source.

• Wind and Structures
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• 제30권3호
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• pp.219-229
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• 2020

Net pressures on roofs and walls of buildings are dependent on the internal and external pressure fluctuations. The variation of internal and external pressures are influenced by the size and location of the openings. The correlation of external and internal pressure influences the net pressures acting on cladding on different parts of the roof and walls. The peak internal and peak external pressures do not occur simultaneously, therefore, a reduction can be applied to the peak internal and external pressures to obtain a peak net pressure for cladding design. A 1:200 scale wind tunnel model study was conducted to determine the correlations of external and internal pressures and effective reduction to net pressures (i.e., net pressure factors, F_C) for roof and wall cladding. The results show that external and internal pressures on the windward roof and wall edges are well correlated. The largest ${\mathcal{C}}_{{\check{p},net}$, highest correlation coefficient and the highest F_C are obtained for different wind directions within 90° ≤ θ ≤ 135°, where the large openings are on the windward wall. The study also gives net pressure factors F_C for areas on the roof and wall cladding for nominally sealed buildings and the buildings with a large windward wall opening. These factors indicate that a 5% to 10% reduction to the action combination factor, K_C specified in AS/NZS 1170.2(2011) is possible for some critical design scenarios.

• 음성과학
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• 제10권2호
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• pp.249-258
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• 2003

This study attempted to examine a speaker identification method using difference sum and correlation coefficient determined from a pair of intensity level matrices of band-pass-filtered numeric sounds produced by ten female speakers of similar age and height. Subjects recorded three digit numbers at a quiet room at a sampling rate of 22 kHz on a personal computer. Collected data were band-pass-filtered at five different band ranges. Then, matrices of five intensity levels at 100 proportional time points were obtained. Pearson correlation coefficients and the sum of absolute intensity differences between a pair of given matrices were determined within and across the speakers. Results showed that very high correlation coefficient and small difference sum generally occurred within each speaker but some individual variation was also observed. Thus, the matrix pair with a higher coefficient and a smaller difference sum was averaged to form each individual's model. Comparison among the speakers yielded generally low coefficients and large differences, which suggests successful speaker identification, but among them there were a few cases with very high coefficients and small differences. Future studies will focus on finer band ranges and additional spectral parameters at some peak points of the intensity contour at a low frequency band.

• 한국항해항만학회지
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• 제29권8호
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• pp.667-671
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• 2005

이 연구는 선박 설계 초기단계에서 선형 변화에 따른 선박 조종성능 추정에 관한 내용을 다루었다. 선박제원을 대표하는 파라메터 그리고 선미형상의 변화를 민감하게 반영할 수 있는 새로운 파라메터를 선정하는 작업을 수행하였다. 이렇게 선정된 파라메터와 유체력 미계수와의 상관관계를 알아보기 위하여 구속모형 실험을 수행하였다. 그 결과 기본적인 선박제원 중 선체 유체력 미계수와 상관도가 높은 파라메터를 가려낼 수 있었다. 또한 선미형상의 새로운 파라메터와 조종성능과의 상관도를 추정할 수 있었다. 또한 이를 활용하여 유체력미계수에 대한 새로운 경험식을 제시하였다. 이를 활용하면, 초기 선형 설계 시 선형변화 및 수정에 따른 조종성능 추정에 활용할 수 있을 것으로 판단된다.

• 가정∙방문간호학회지
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• 제26권3호
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• pp.265-277
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• 2019

Purpose: This study was performed to explore research trends in the intention to stay of hospital nurses and provide basic data to establish nursing management strategies to increase the intention to stay. Methods: Articles published between 2009 and 2018 were searched. The search terminologies were "intention to stay," "nurse", and "hospital". In the first search, 381 articles were extracted from academic databases. Thirty articles were used in the systematic review, and 29 articles were used in the correlation meta-analysis. Results: Thirty-two variables were explored in relation to the intention to stay. In the correlation analysis, job satisfaction and work environment showed statistically significant positive correlations in many studies. In the correlation meta-analysis, 7 variables including organizational commitment showed statistically significant effect sizes. Conclusion: We suggest that structural equation model analysis to identify causal relations among influencing variables of the intention to stay of hospital nurses may be conducted. This study can be used as a guideline to develop intention-to-stay enhancement programs for hospital nurses.

• Environmental Engineering Research
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• 제15권4호
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• pp.191-195
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• 2010

This study was carried out to investigate the important factors relating to runoff and pollutant loads in a plot unit located in an agricultural area. Of the precipitation parameters, such as total precipitation, days since last rainfall (ADD, the rainfall was more than 10mm) and average rainfall intensity on runoff, the strongest effect was obtained due to total precipitation, but the rainfall intensity showed a slightly positive correlation. It was expected that both variables, i.e. total precipitation and rainfall intensity, would lead to the generation of greater runoff. In contrast, runoff was negatively correlated with ADD, which is understandable because more infiltration and less runoff would be expected after a long dry period. The TSS load varied greatly, between 75.6 and $5.18{\times}10^4g$, per event. With the exception of TN, the TSS, BOD, COD and TP loads were affected by runoff. The correlations of these items were proportional to the runoff volume, with correlation coefficients (r) greater than 0.70, which are suitable for use as NPS model data. The TSS load showed very good relationships with organics (BOD & COD) and nutrients (TN & TP), with correlation coefficients greater than 0.79. Therefore, the removal of TSS is a promising factor for protecting water basins.

• 대한안전경영과학회지
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• 제18권3호
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• pp.99-107
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• 2016

The purpose of this study includes: Firstly, to examine the effects of authentic leadership on leader trust, self efficacy, and creative behavior. Secondly, to examine the mediating effect of the leader trust, self efficacy on the relationship between authentic leadership and creative behavior. In order to verify the relationships and mediating effect, data were collected from convenient sample of 323 employees at small and medium enterprises in Busan, Ulsan, Gyeongju city to test theoretical model and its hypotheses. All data collected from the survey were analyzed using with SPSS 18.0 and AMOS 18.0. This study reports findings as followed: first, the relationship between the authentic leadership and the leader trust is positively related. Second, there was also a positive correlation between the authentic leadership and the self efficacy. Third, there was also a positive correlation between the authentic leadership and the creative behavior. Fourth, the relationship between the leader trust and the self efficacy is positively related. Fifth, there was also a positive correlation between the leader trust and the creative behavior. Sixth, there was also a positive correlation between the self efficacy and the creative behavior. Finally, the leader trust and self efficacy played as a partial mediator on the relationship between authentic leadership and creative behavior. Based on these findings, the limitations of the study and some directions for future studies were presented.

• Wind and Structures
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• 제15권5호
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• pp.423-439
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• 2012

Three common medium- rise building forms were physically tested to study their overall wind induced structural response. Emphasis was placed on the torsional response and its correlation with other peak responses. A higher correlation was found between the peak responses than between the general fluctuating parts of the signals. This suggests a common mechanism causing the peak event, and that this mechanism is potentially different to the mechanism causing the general load fluctuations. The measurements show that about 80% of the peak overall torsion occur simultaneously with the peak overall along wind drag for some generic building shapes. However, the peak torsional response occurs simultaneously with only 30%-40% of the peak overall drag for the rectangular model. These results emphasise the importance of load combinations for building design, which are often neglected in the design of medium sized rigid buildings for which the along-wind drag is dominant. Current design wind loading standards from around the world were evaluated against the results to establish their adequacy for building design incorporating wind-induced torsion effects. Although torsion is frequently neglected, for some structural systems it may become more important.

• 동서간호학연구지
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• 제20권1호
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• pp.29-36
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• 2014

Purpose: The purpose of this study is to identify relationships among work environment, job satisfaction and turnover intention of emergency department (ED) nurses. Methods: The survey was given to 220 ED nurses which are located in G metropolitan from May 1st to July 31st of 2012. The results were analyzed by descriptive statistics, t-test, ANOVA, pearson correlation coefficients and stepwise multiple regression using SPSS WIN 19.0 program. Results: The turnover intension according to the general characteristics of the subjects has significant difference between emergency room experience, current duty satisfaction, and turnover plan in 1 year. In the correlation between work environment, job satisfaction and turnover intention of the subjects, work environment and job satisfaction have positive correlation, job satisfaction and turnover intention either job satisfaction and turnover intention have a negative correlation. Factors influencing turnover intention are job satisfaction, career and current duty satisfaction, also the full explanatory power of the model was 24.4%. Conclusion: The results indicate factors that influence turnover intention are job satisfaction, career, and current job satisfaction. We hope these result help to provide effective intervention strategies for reducing ED nurses' turnover.

• 기본간호학회지
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• 제16권1호
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• pp.56-63
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• 2009

Purpose: The purpose of this study was to identify self-efficacy, disposition to critical thinking and level of nursing competency in new nurses and to exam the correlation among these variables. Method: The sample was composed of 286 new nurses who had worked at E hospital for 1 year. Descriptive and correlation analysis using the SPSS program were used to analyze the data. Results: The mean score for self-efficacy was 67.10, disposition to critical thinking, 3.01 and nursing competency, 3.02. There were significant differences in scores for 3 variables between nurses with College degrees and nurses with Baccalaureate degrees. There was a significant positive correlation between disposition to critical thinking and nursing competency scores. Conclusion: Further study of the various components that influence nursing competency is necessary. Also based on the disposition to critical thinking, there is a need to develop education programs to strengthen curiosity and other related variables. The results of this study confirmed the necessity of developing a clinical model of nursing competency ability.