• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.4
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• pp.303-308
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• 2015

Cultivating genetically modified (GM) crops is believed to be a practical solution to meet the increasing food demand, but GM crops are not legal in Korea mainly due to food safety issues. Even though the general public might not be ready to consume GM food, GM crops are imported and consumed as food and feed. To analyze farmers's willingness to grow GM crops for feed, a survey was conducted among crop farmers and 640 valid responses were collected by mail. In the questionnaire, the farmers were asked to select either 'yes' or 'no' if they were willing or not willing to cultivate GM rice and GM grass, respectively, under the given hypothetical income increase rate (i.e., 10%, 20%, 30%, 40%, 50%, 60%, or 70%). Logit regression was used to estimate the two dichotomous choices by explanatory variables including hypothetical income increase rate. The results show that farmers are willing to cultivate GM rice and grass when their income is expected to increase by 47% and 43%, respectively.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.255-263
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• 2016

This study conducted empirical tests on contemporary finance theories for corporate cash holdings, such as trade-off, pecking order, and agency theory. There is ongoing debate on the possibility of excess cash savings by domestic firms, including chaebols in the Korean capital markets. Thus, it may be worthy to identify any financial characteristics based on each aforementioned theory as an extension of previous studies on similar subjects. Two primary hypotheses were postulated and tested, and the following empirical results were obtained. First, principal component analysis (PCA) provides evidence that nine out of the twenty explanatory variables showed a significant influence on the level of corporate cash holdings, such as cash conversion cycle in trade-off theory and leverage in pecking order theory. Second, the chaebol firms that decreased cash holdings after global financial turmoil may be affected by financial factors that include investment opportunities and foreign ownership according to the PCA. The results may reinforce the outcomes derived from previous research on corporate cash holdings. Based on the robust results, large firms in advanced or emerging capital markets could approach the optimal level of the cash reserves.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5314-5324
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• 2015

The present study was intended to measure the relationship between job stress and job satisfaction among nurses working for a general hospitals. The self-administered questionnaires were given to 312 nurses during the period from February 25 to March 16, 2013. As a results, the level of job satisfaction of subjects was significantly lower in high group than low group in job demand, but it was significantly lower in low group than high group in job control, supervisor support and coworker support. In correlations, job satisfaction were found to be in a negative correlation with job demand, whereas in positive correlation with job control, supervisor and coworker support. In logistic analysis, the odds ratio of job satisfaction on job demand were significantly increased in the high group than in low group, but job control supervisor and coworker support were significantly decreased in the high group than in low group. In hierarchial multiple regression analysis, the affecting factors to the job satisfaction was selected variables such as educational background, work station, subject satisfaction of work, career choice motives, turnover experience, job stress contents(job demand, job control, supervisor support and coworker support). especially, job stress contents was significantly increased of explanatory power of job satisfaction. It suggested that the level of job satisfaction got more power by addition of job stress contents.

• Journal of Educational Research in Mathematics
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• v.23 no.4
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• pp.467-490
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• 2013

Correlation is a basic statistical concept which is necessary for understanding the relationship between two variables when they change values. In the middle school curriculum of Korea, only informal definition of correlation is taught with two-way data representations such as scatter plots and contingency tables. In this study, we investigated Korean high school students' understanding of correlation using a test consisting of 35 items about interpretation of scatter plot, contingency table, and text in realistic situation. 216 students from a high school in Seoul took the test for 20 minutes. From the results, we could observe the following: First, students did not have right criteria for determining the strength of correlation presented in scatter plots. Most of students could determine if there is correlation/no correlation and if the correlation is positive/negative by seeing the data presented in scatter plots. However, they did not judge by the closeness to the regression line but rather judged by the closeness between data points. Second, when statements about comparing the strength of correlation in the context of real life situation were given in text, the students had difficulty in understanding the distribution-related characteristic of the bi-variate data. Students had difficulty in figuring out the local distribution characteristic of data, which cannot be guessed merely based on the expression 'The correlation is strong' without statistical knowledge of correlation. Third, a large number of students could not judge the association between two variabels using conditional proportions when qualitative data are given in 2-by-2 tables. They made judgement by the absolute cell count and when the marginal sum of two categories are different for explanatory variable they thought the association could not be determined. From these results, we concluded that educational measures are required in order to remove such misconceptions and to improve understanding of correlation. Considering that the current mathematics curriculum does not cover the concept of correlation, we need to improve the curriculum as well.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.1-9
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• 2018

The purpose of this study is to identify the factors affecting the treatment outcome after surgical-orthodontic treatment of the maxillary impacted incisors using multiple regression analysis. The study enrolled 83 patients who had surgical-orthodontic treatment in impacted maxillary central incisor between January 2005 and December 2015. Possible explanatory variables related to the prognosis of impacted incisor were age, gender, tooth developmental stage, height, position and angle of the teeth. The results of multiple regression analysis showed that as the height of the stem cell from apical papilla (SCAP) increased, the tooth length ratio increased by 0.345 units (p < 0.01). There was no statistically significant difference in gender, tooth development stage, distance and angle between the center line and the tooth, and the height of incisal tip of the tooth. In conclusion, the height of the SCAP of the impacted central incisor is factor affecting the tooth length after orthodontic traction.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.343-353
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• 2016

This study was done to identify variables predicting of nursing performance with basic psychological need, self-leadership and job stress in clinical nurses. The participants were 160 clinical nurses, located in P city and D province in korea. Data were collected from Feb to March, 2016 by questionnaire survey. Data analysis was done by using SPSS WIN 18.0 program with independent t-test and analysis of variance, Pearson's correlation analysis, and multiple linear regression. This study shows positive correlations between nursing performance and basic psychological needs(r=.59, p<.001), autonomy(r=.31, p<.001), competency(r=.68, p<.001), relatedness(r=.48, p<.001), self-leadership(r=.58, p<.001), job stress(r=.19, p<.05). Basic psychological needs(${\beta}$=.43), self-leadership(${\beta}$=.33), job stress(${\beta}$=.21) have a 47.3%(Adj $R^2$ .473) explanatory power for the nursing performance in clinical nurses. This study confirmed that basic psychological needs, self-leadership and job stress were identified to improve nursing performance. Therefore we should develop programs in order to increase basic psychological needs and self-leadership.

• Journal of Digital Convergence
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• v.12 no.11
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• pp.575-583
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• 2014

The purpose of this study was to investigate factors affecting depression among female marriage immigrants in relation to demographic, family, self-efficacy, acculturation, and physical health aspects. The subjects were 556 marriage immigrants residing in Seoul, Keong-gi, and Chung-cheong areas. 47.1% of the subjects showed $${\geq_-}16$$ of CES-D which is the cutting points on depression. The results from hierachical regression analysis indicated that family income(${\beta}=-.13$, p=.002) at the first demographic model and self-efficacy(${\beta}=-.13$, p<.001), family relationship(${\beta}=-.16$, p<.001), acculturation to Korean culture(${\beta}=-.08$, p=.05), acculturative stress(${\beta}=.31$, p<.001), and mal-physical health(${\beta}=.18$, p<.001) at the final model affected female marriage immigrants' depression. The explanatory power of these variables was 37.1%. Based on these results, social services and policies for the prevention of depression among female marriage immigrants were discussed.

• The Journal of the Korea Contents Association
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• v.12 no.11
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• pp.338-357
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• 2012

This study investigated any possible financial attributes of the CDS spreads of a firm belonging to financial industries headquartered in the Republic of Korea. There were few studies on this issue, especially for the firms located in emerging capital markets. Coupled with the models such as a multiple regression and a principal component analysis(PCA), this research has identified that only two explanatory variables such as SLOPE and INTER3 (i.e. interaction effect between the BETA and the SLOPE) consistently showed their statistically significant influence on the CDS spreads through the 'selected' model without and with applying a stepwise regression procedure for the robustness. Given the rapid developments of sophisticated financial derivatives, this study may suggest a valuable insight to foreign and domestic investors to identify the possible determinants of CDS spreads at the firm- and/or the industry-level.

• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.196-209
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• 2018

This study is founded on banks' profitability factors. Unlike the previous study in terms of diversification of the banks' funding structure, this research performs multiple regression analysis during the entire period and examines the comparative analysis of before and after the financial crisis. the study establishes hypotheses by using the wholesale funding ratio as a key focus variable with 8 explanatory variables and the operating profit on assets as a profitability index. The Loan-deposit rate gap, the Number of stores and the Non-performing loan ratio prove to be a significant profitability factor for all periods of time. Korean banks are also more profitable when their the Loan-deposit rate gap get bigger and the Number of stores grows. The wholesale funding ratio is analyzed to have no statistically significant effect on the profitability of banks. Rather than being influenced by macroeconomic indicators, it is indicated that the situation of individual banks and other financial environments have been affected. And banks increase profitability as banks increase their loan after the financial crisis. The empirical analysis shows that profitability factors have periodical distinctions, and in this aspect, this research has implications. The study needs to be expanded to cover the entire domestic banking sector, in consideration of the profitability of the banking industry in the future.

• Journal of Digital Convergence
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• v.18 no.1
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• pp.257-263
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• 2020

This study was conducted to improve the quality of National Health Policy by analysing the effects of sociodemographic characteristics, Medical institutions characteristics and characteristics of Admission-Discharge on the length of stay in hospital for schizophrenic patients from the data of Health Insurance Review & Assessment Service. The subjects were 4,692 patients who were diagnosed with schizophrenia as main diagnosis from the data records of HIRA-NIS 2016. Regression analysis was performed to evaluate the effect on the length of stay. Sociodemographic characteristics, hospital characteristics and characteristics of Admission-Discharge were used as explanatory variables and length of stay in hospital was used as a dependent variable. The result of study showed that female, age, medical aid, the kind of hospital, gangweon-do and with mental disease were found to be the factors that affect the length of stay. The significance of this study is to use the public data for evaluating factors that affect the length of stay in hospital for schizophrenic patients. But this study did not consider disease severity, so further study is needed for evaluation of the effects of factors on the length of stay according to disease severity.