• Journal of agriculture & life science
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• v.44 no.1
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• pp.33-42
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• 2010

This study was conducted to estimate the effects of breed, sex, Farm-Scale and environment on average daily gain, age at 90kg, backfat thickness, eye muscle area and lean percent of pig. The total number of pig used in this study was 30,525 head consisted of 5,902 Landrace, 18,022 Yorkshire, and 6,601 Duroc on 2004 to 2008. The covariance used in the model to adjust age at the final test. The average daily gain, age at 90kg, and lean percent were significantly superior in medium Farm-Scale. However Backfat thickness and Eye muscle Area were significantly superior in small Farm-Scale. In conclusion this study suggest that breed, sex, test year, test season, Farm-Scale and environment may affect to average daily gain, age at 90kg, backfat thickness, eye muscle area and lean percent. The study about the Farm-Scale has to do continually more than now, and this study will be contributed to development of the pig industry.

• Korean Journal of Social Welfare Studies
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• v.44 no.1
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• pp.135-164
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• 2013

The purpose of this research is to examine the effects of family social capital and community social capital on how successfully children adapt to school. Utilizing the second year data from the 1st year of middle school panel found in the 2010 Korea Children and Youth Panel Survey, descriptive statistical analysis, correlation analysis, and hierarchical linear model analysis were conducted successively on 2,056 second-year middle school students living in 93 communities. The data produced was used to determine what degree of influence family social capital and community social capital exert on the ability of children to successfully adapt to school. First, 6.1% of the variables relating to school adaptation were explained by differences among communities, and the remaining 93.3% were explained by differences among individuals. Second, the examination of the effects of family social capital showed that students who experienced lower rates of neglect also experienced less abuse, had parents who were more interested in and better informed about their lives, and better adapted to school. Third, the examination of the effects of community social capital showed that the higher the community spirit the communities had, the better the young students in the communities adapted to school. Fourth, when the effects of family social capital and community social capital were examined in conjunction with each other, it was found that the less neglect the students experienced, the less abuse the students experienced, the greater the interest their parents had in their close friends, the better they themselves adapted to school. In relation to community social capital, the level of community spirit was still found to exert positive effects on the ability of young students to successfully adapt to school.

• Korean Journal of Environmental Agriculture
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• v.40 no.4
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• pp.248-259
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• 2021

BACKGROUND: Contaminated water was a major source of food-borne pathogens in various recent fresh produce-related outbreaks. This study was conducted to investigate the microbial contamination level and correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water by logistic regression analysis. METHODS AND RESULTS: Agricultural water was collected from 457 sites including surface water (n=300 sites) and groundwater (n=157 sites) in South Korea from 2018 to 2020. Sanitary indicator bacteria (total coliform, fecal coliform, and Escherichia coli) and food-borne pathogens (pathogenic E. coli, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes) were analyzed. In surface water, the coliform, fecal coliform, and E. coli were 3.27±0.89 log CFU/100 mL, 1.90±1.19 log CFU/100 mL, and 1.39±1.26 log CFU/100 mL, respectively. For groundwater, three kinds of sanitary indicators ranged in the level from 0.09 - 0.57 log CFU/100 mL. Pathogenic E. coli, Salmonella and Listeria monocytogenes were detected from 3%-site, 1.5%- site, and 0.6%-site water samples, respectively. According to the results of correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens by logistic regression analysis, the probability of pathogen detection increased individually by 1.45 and 1.34 times as each total coliform and E. coli concentration increased by 1 log CFU/100mL. The accuracy of the model was 70.4%, and sensitivity and specificity were 81.5% and 51.7%, respectively. CONCLUSION(S): The results indicate the need to manage the microbial risk of agricultural water to enhance the safety of fresh produce. In addition, logistic regression analysis is useful to analyze the correlation between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.363-373
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• 2021

An ecological niche is defined as the specific role of a species influenced by time, space, and other resources. By investigating overlaps between ecological niches of different species, we could estimate the degrees of interspecific competition. Such studies often use geographic information systems (GIS) to discover niche overlaps between species. In this study, we used GIS to estimate the spatial niches of two Korean frog species(Pelophylax nigromaculatus and P. chosenicus). This enabled us to predict their geographic distributions in order to identify their coexistence regions and distribution patterns. The results confirmed that altitude was an important variable for predicting their distribution, with a correlation with their climatic range. Spatial distributions of the two frog species were highly overlapped, as the distribution range for P. nigromaculatus included most of the range of P. chosenicus, showing a sympatric distribution pattern. Within the coexisting regions, however, the presence sites for the two species did not overlap, implying weak competition. To confirm the principal factors influencing their competitive relationship and reasons for their sympatric distribution pattern, we need more detailed in-depth studies on the diverse environmental variables within the regions where the two species coexist. By doing so, we would be able to identify various mechanisms for avoiding competition in sympatric frog species.

• Journal of Korea Port Economic Association
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• v.36 no.4
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• pp.93-106
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• 2020

Trade is an important economic activity. In particular, since the establishment of the World Trade Organization (WTO), the scope of trade has been expanding due to events such as the entry of China into the WTO in 2001, the establishment of a multilateral trading system, mitigation and integration of trade barriers, and the establishment of the free trade agreement (FTA). Despite the expansion of the trade market, however, extreme events such as the 2008 global financial crisis, the 2016 Brexit, and the 2018 US-China trade war have had a direct negative impact on the trade market. Therefore, the present this study analyzed the dependence structure between the international shipping freight rate index, a variable representing trade activities, and the trade uncertainty between the US and China. The following is a summary of the analysis results. First, the US-Chinese trade policy uncertainty and international shipping freight rate index presented a Frank copula and rotated Clayton copula 270° distribution, respectively, showing the same distribution structure for each country. Second, the Kendall's tau correlation revealed a negative dependence between the international shipping freight rate index and US-Chinese trade policy uncertainty. The degree of dependence was greater in the combination of uncertainty in China's trade policy and international shipping freight rates. In other words, the dependence of global demand and trade policy uncertainty confirmed that China was stronger than the US. Finally, the tail dependence results revealed that the US-Chinese trade policy uncertainty and international shipping freight rates were independent of each other. This means that extreme events related to the trade policy uncertainty or international shipping rate index were not affected by each other.

• International Area Studies Review
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• v.14 no.1
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• pp.55-76
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• 2010

This paper analyses interaction between yen/dollar exchange rates and NIKKEI index using bivariate GJR-GARCH(1,1) model. The data employed for the study is daily data series for the period of Jan. 4, 1995 through Aug. 30, 2009. One of main findings is that market inefficiency appears in the periods of financial crisis. Second, the volatility of exchange rates and stock returns has more increased in the wake of the volatility shock of the previous period during financial crisis than during non-financial crisis. Third, interestingly, the asymmetric volatility shock by bad news in those markets is bigger in financial crisis period than in non financial crisis. Fourth, in the period of current global financial crisis triggered by subprime mortgage crisis in U.S, volatility shock at the previous period is bigger than that of Asian financial crisis that happened in 1997. Lastly, the correlation between both returns of exchange rates and stock prices turns up positive according to the empirical estimation. This result may come from the fact that Japanese stock market does not have much attraction for international financial investment compared to stock markets of neighbouring countries like China, Korea and so on, while real sector's contribution to the economy is considered more importantly.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.662-671
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• 2018

This study was designed to investigate the impact of stress coping ability and recovery resilience on nurses' retention intent in medium-sized hospitals. For this descriptive study, a survey was conducted with 265 nurses from 5 medium-sized hospitals with over 150 sickbeds located in G and I province; the data were collected from May 19 to May 25, 2018. The collected data were analyzed by t-test, ANOVA, Pearson's correlation coefficients, and multiple regression. The average score was $2.55{\pm}0.25$ for stress coping ability, $3.47{\pm}0.49$ for recovery resilience, and $2.59{\pm}0.29$ for retention intent. Retention intent was positively correlated with stress coping ability (r=0.285, p<0.01) and recovery resilience (r=0.457, p<0.01). The factors affecting retention intent were gender (${\beta}=0.117$, p=0.027), job satisfaction (${\beta}=0.345$, p<0.001), stress coping ability (${\beta}=0.142$, p=0.008), and recovery resilience (${\beta}=0.238$, p<0.001). Furthermore, the model explained 37.8% of the retention intent (F=11.686, p<0.001). In conclusion, effective strategies for improving job satisfaction, stress coping ability, and recovery resilience for nurses need to be developed and investigated.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.701-710
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• 2018

This study aims to verify the mediating effect of perceived risk of internet shopping mall users' innovativeness on product purchase intention. Research subjects included consumers with prior experience of using internet shopping malls, and 405 respondents were used for final analysis. The major findings of the study are as follows: First, as a result of the investigation on the relationships among users' innovativeness, perceived risk, and product purchase intention, all correlation coefficients were positive. Second, consumer innovativeness was found to significantly influence perceived risk and purchase intention, and perceived risk mediated the relationship between consumer innovativeness and purchase intention. Third, when we performed sub-group analysis on the research model by dividing products into hedonic and utilitarian products, it was found that hedonic products revealed path coefficients which are statistically more significant compared with those for utilitarian products. We can draw the conclusion that in terms of internet shopping mall purchases, hedonic products exert a greater influence on the effect of consumer innovativeness on purchase intention compared to utilitarian products.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.572-583
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• 2019

This study sought to find out what the most ideal and appropriate native English speakers-Korean English teacher cooperative class model and the defining factors for organizing effective cooperative classes in the English education environment of our country. To achieve this goal, a total of 165 sixth graders of five elementary schools in Seoul were subject to the study. For about a month from April 1 to April 30, 2019, the survey and statistical analysis were conducted, including multiple return analysis, correlation analysis, cross analysis, and t/F verification. In summary, the results of the study are as follows. First, it was found that among the recognition of cooperative classes between native English speakers and Korean English teachers, it affected the defining factors in the order of class-related skills, task orientation, teaching-learning strategies, and motivation. Second, based on learner characteristics, the difference in perception of cooperative classes between native English speakers and Korean English teachers was verified, and the perception of native-Korean English teachers' cooperative classes was different depending on gender and the type of English cooperative classes currently participating, but the recognition of native-Korean English-Korean English cooperative classes, which were statistically significant, was not confirmed. Third, according to learner characteristics, the difference in the definition factors of the learner was verified and the difference between the sexes occurred, but the learner-defined factors according to the current type of English cooperative class did not occur. Also, there was no difference in the definition factors of scholars according to the type of English cooperative classes desired.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.3
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• pp.491-501
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• 2019

In side-channel analysis, which exploit physical leakage from a cryptographic device, deep learning based attack has been significantly interested in recent years. However, most of the state-of-the-art methods have been focused on classifying side-channel information in a profiled scenario where attackers can obtain label of training data. In this paper, we propose a new method based on deep learning to improve non-profiling side-channel attack such as Differential Power Analysis and Correlation Power Analysis. The proposed method is a signal preprocessing technique that reduces the noise in a trace by modifying Auto-Encoder framework to the context of side-channel analysis. Previous work on Denoising Auto-Encoder was trained through randomly added noise by an attacker. In this paper, the proposed model trains Auto-Encoder through the noise from real data using the noise-reduced-label. Also, the proposed method permits to perform non-profiled attack by training only a single neural network. We validate the performance of the noise reduction of the proposed method on real traces collected from ChipWhisperer board. We demonstrate that the proposed method outperforms classic preprocessing methods such as Principal Component Analysis and Linear Discriminant Analysis.