• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.2
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• pp.62-72
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• 2017

Spatio-temporal projection of evapotranspiration over croplands would be useful for assessment of climate change impact and development of adaptation strategies in agriculture. Potential evapotranspiration (PET) and dryness index (DI) during rice growing seasons were calculated using climate change scenario data provided by the National Institute of Meteorological Research (NIMR). A data processing tool for gridded climate data files, readGrADSWrapper, was used to calculate PET and DI during the current (1986-2005) and future (2006-2100) periods. Scripts were written to implement the formulas of PET and DI in R, which is an open source statistical data analysis tool. Evapotranspiration in rice fields ($PET_{Rice}$) was also determined using R scripts. The Spatio-temporal patterns of PET differed by regions in Korean Peninsula under current and future climate conditions. Overall, PET and $PET_{Rice}$ tended to increase throughout the $21^{st}$ century. Those results suggested that region-specific water resource managements would be needed to minimize the risk of water loss in the regions where considerable increases in PET would occur under the future climate conditions. For example, a number of provinces classified as a humid region were projected to become a sub-humid region in the future. The Spatio-temporal assessment of water resources based on PET and DI would help the development of climate change adaptation strategies for rice production in the 21st century. In addition, the studies on climate change impact would be facilitated using specialized data tools, e.g., readGrADSWrapper, for geospatial analysis of climate data.

• Journal of the Microelectronics and Packaging Society
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• v.21 no.4
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• pp.1-13
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• 2014

The paper gives an overview of the concepts, basic requirements, and trends regarding packaging technologies of power modules in hybrid (HEV) and electric vehicles (EV). Power electronics is gaining more and more importance in the automotive sector due to the slow but steady progress of introducing partially or even fully electric powered vehicles. The demands for power electronic devices and systems are manifold, and concerns besides aspects such as energy efficiency, cooling and costs especially robustness and lifetime issues. Higher operation temperatures and the current density increase of new IGBT (Insulated Gate Bipolar Transistor) generations make it more and more complicated to meet the quality requirements for power electronic modules. Especially the increasing heat dissipation inside the silicon (Si) leads to maximum operation temperatures of nearly $200^{\circ}C$. As a result new packaging technologies are needed to face the demands of power modules in the future. Wide-band gap (WBG) semiconductors such as silicon carbide (SiC) or gallium nitride (GaN) have the potential to considerably enhance the energy efficiency and to reduce the weight of power electronic systems in EVs due to their improved electrical and thermal properties in comparison to Si based solutions. In this paper, we will introduce various package materials, advanced packaging technologies, heat dissipation and thermal management of advanced power modules with extended reliability for EV applications. In addition, SiC and GaN based WBG power modules will be introduced.

• Journal of the Korean Dietetic Association
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• v.13 no.3
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• pp.228-239
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• 2007

The purpose of this study was to identify the variables of foodservice employees's job satisfaction. The questionnaires to measure job satisfaction were completed by 323 employees in the Gyunggi province. Foodservice employees' job satisfaction was evaluated by the modified Smith method(1969). All statistical data analyses were conducted using the Statistical Package for the Social Science(SPSS version 12.0). The study results were as follows; 1. The demographic data showed that 65.3% of respondents aged in 40~49 years old, 96% were married, 68.8% were high school graduates, 10.2% were college graduates and 93.5% were contracted employees. 2. Factors that influenced job satisfaction among employees varied significantly. Older workers tended to be more satisfied in their job. In addition, those who had graduated college showed the highest job satisfaction score(3.03). Subjects who had graduated university showed the lowest job satisfaction score(2.05). Subjects who had worked for 2-3 years showed the highest satisfaction scores concerning their relationships with coworkers(3.33), whereas those who had worked less than 2 years showed the lowest (3.14). Regarding school type, employees working in high schools had the highest job satisfaction scores, whereas those working in middle schools had the lowest. Satisfaction of leaving school time, ‘after 4 pm group’ had the highest score(3.01). 3. The correlation between salary satisfaction and job satisfaction was significant(r=0.307, p<0.001). In addition, the correlation between job satisfaction and work satisfaction was also significant(r=0.444, p<0.001). The correlation between job satisfaction and satisfaction about relations with coworkers was significant(r=0.118, p<0.01). The correlation between salary satisfaction and work satisfaction was significant(r=0.308, p<0.001). The correlation between salary satisfaction and satisfaction about relation with coworkers not significant, but it was negative(r=0.307, p<0.001). The correlation between work satisfaction and satisfaction about relations with coworkers significant(r=0.210, p<0.001). According to this study, job satisfaction and salary were positively related. This study provides foodservice managers useful information for design positions that will increase productivity. Future study is needed to determine the factors that will improve job satisfaction and satisfy the employees' needs, which in turn will improve school food service quality.

• Journal of dental hygiene science
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• v.15 no.3
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• pp.355-360
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• 2015

The purpose of this study was to examine the relationship between the oral health behavior and self-efficacy of adolescents. The subjects in this study were 300 selected students in a girls' high school located in the city of Iksan. A survey was conducted from November 2 to 5, 2014, with questionnaires that covered oral health behavior and self-efficacy, and the answer sheets from 298 respondents were analyzed by a statistical package IBM SPSS Statistics ver. 21.0. The group that got regular dental checkups (3.26) excelled the other group that didn't in self-efficacy (p<0.05), and the group who made use of oral care products and who brushed their teeth four times or more had a better self-efficacy than the other group that didn't. The students who considered themselves to be in better oral health scored higher in self-efficacy, and the groups who had no difficulties in pronunciation (3.66) and mastication (3.32) scored higher (p<0.01, <0.001). Masticatory dysfunction (r=-0.184) and pronunciation disorder (r=-0.200) were negatively correlated with self-efficacy, but oral health status (r=0.243) had a positive correlation with it. Self-efficacy was better when oral health status was better (p<0.001) and when there was no pronunciation disorder (p<0.01). The above-mentioned findings suggested that there was a close relationship between oral health behavior and self-efficacy. Therefore the kind of program that aims at changing youth oral health awareness and oral health behavior should be prepared to improve the self-efficacy of adolescents.

• Korean Journal of Psychosomatic Medicine
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• v.24 no.2
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• pp.140-145
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• 2016

Objectives : Parental behavior is related to personality development and ego resilience in the childhood. The objective of this study was to identify the influence of parental behavior on ego resilience in Korean middle school student. Methods : Subjects were selected based on stratified multi-stage cluster sampling in Korea youth panel study 2013(Boy : N=1,075, Girl : N=1,033). We used Parental behavior inventory(PBI) to estimate parental behavior and the Ego resilience scale to estimate ego resilience. The data were statistically analyzed using a Pearson correlation analysis and regression analysis with the statistical package for the social sciences(SPSS). We considered differences to be significant when p<0.05. Results : A regression analysis showed that rational explanation, affection, Interest and inconsistency of the parental behavior domains influence ego resilience. Also rational explanation, affection and Interest of the parental behavior domains showed a significant positive correlation with ego resilience(r=0.24, r=0.31, r=0.22, p<0.01). In contrast to early childhood studies, inconsistency showed no significant correlation. Conclusions : Adolescents who had taken more rational explanation, interest and affection from their parents were more likely to have higher ego resilience. However, inconsistency of parental behavior showed no correlation with ego resilience of adolescents, which means that they are affected by several other factors than parental behavior. This study would be a basic research that could be a help to psychosocial approach in pediatric psychiatry.

• Journal of Internet Computing and Services
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• v.16 no.2
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• pp.57-66
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• 2015

Considerable research efforts are being directed towards analyzing unstructured data such as text files and log files using commercial and noncommercial analytical tools. In particular, researchers are trying to extract meaningful knowledge through text mining in not only business but also many other areas such as politics, economics, and cultural studies. For instance, several studies have examined national pending issues by analyzing large volumes of text on various social issues. However, it is difficult to provide successful information services that can identify R&D documents on specific national pending issues. While users may specify certain keywords relating to national pending issues, they usually fail to retrieve appropriate R&D information primarily due to discrepancies between these terms and the corresponding terms actually used in the R&D documents. Thus, we need an intermediate logic to overcome these discrepancies, also to identify and package appropriate R&D information on specific national pending issues. To address this requirement, three methodologies are proposed in this study-a hybrid methodology for extracting and integrating keywords pertaining to national pending issues, a methodology for packaging R&D information that corresponds to national pending issues, and a methodology for constructing an associative issue network based on relevant R&D information. Data analysis techniques such as text mining, social network analysis, and association rules mining are utilized for establishing these methodologies. As the experiment result, the keyword enhancement rate by the proposed integration methodology reveals to be about 42.8%. For the second objective, three key analyses were conducted and a number of association rules between national pending issue keywords and R&D keywords were derived. The experiment regarding to the third objective, which is issue clustering based on R&D keywords is still in progress and expected to give tangible results in the future.

• Journal of the Microelectronics and Packaging Society
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• v.24 no.2
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• pp.11-15
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• 2017

As the heat dissipation problem is increased in 3D multi flip chip packages, an improvement of thermal conductivity in bonding interfaces is required. In this study, the effect of alumina filler addition was investigated in non-conductive paste(NCP). The fine alumina filler having average particles size of 400 nm for the fine pitch interconnection was used. As the alumina filler content was increased from 0 to 60 wt%, the thermal conductivity of the cured product was increased up to 0.654 W/mK at 60 wt%. It was higher value than 0.501 W/mK which was reported for the same amount of silica. It was also found out that the addition of fine sized alumina filler resulted in the smaller decrease in thermal conductivity than the larger sized particles. The viscosity of NCP with alumina addition was increased sharply at the level of 40 wt%. It was due to the increase of the interaction between the filler particles according to the finer particle size. In order to achieve the appropriate viscosity and excellent thermal conductivity with fine alumina fillers, the highly efficient dispersion process was considered to be important.

• Journal of Technology Innovation
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• v.29 no.3
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• pp.63-90
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• 2021

Today, venture companies are increasingly important in that they play a key role in national economic growth. However, ICT venture companies are having great difficulties in securing a sustainable competitive advantage due to rapid environmental changes, and as one of the ways to solve this problem, they rely on the government's support policy. Accordingly, this study analyzed the effect of government support on management performance of ICT venture companies. For empirical analysis, the data from the 2016 ICT venture panel survey was collected, and 687 and 538 companies were selected to analyze the effect of funding and R&D support, respectively. Then, through propensity score matching, companies that received government support and companies with similar characteristics (control group) were compared and analyzed. As a result of the analysis, it was found that funding support had a significant effect on the growth potential of ICT venture companies, and R&D support had a significant effect on the stability of ICT venture companies. This means that there is a difference in management performance of ICT venture companies depending on the type of government support. Through this study, it was possible to confirm the effect of government's policies, and various support policies for specific purposes should be pursued to foster ICT venture companies. In addition, for the continued growth of ICT venture companies in the future, it will be necessary to consider package (technology, management, commercialization, etc.) support rather than individual funding support or R&D support.

• Korean Journal of Agricultural and Forest Meteorology
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• v.24 no.4
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• pp.337-345
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• 2022

For data such as rainfall and soil moisture, it is important to obtain the values of all points required as geostatistical data. Spatial interpolation is generally performed in this process, and commercial software such as ArcGIS is often used. However, commercial software has fatal drawbacks due to its high expertise and cost. In this study, R, an open source-based environment with ArcGIS, a commercial software, was used to compare the differences according to the processing environment when performing spatial interpolation. The data for spatial interpolation was weather forecast data calculated through Land-Atmosphere Modeling Package (LAMP)-WRF model, and soil moisture data calculated for each cumulative rainfall scenario. There was no difference in the output value in the two environments, but there was a difference in user interface and calculation time. The results of spatial interpolation work in the test bed showed that the average time required for R was 5 hours and 1 minute, and for ArcGIS, the average time required was 4 hours and 40 minutes, respectively, showing a difference of 7.5%. The results of this study are meaningful in that researchers can derive the same results in a commercial software environment and an open source-based environment, and can choose according to the researcher's environment and level.

• Korean Journal of Agricultural Science
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• v.43 no.5
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• pp.715-722
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• 2016

Rapid determination of food quality is important in food distribution. In this study, the chemical properties of oats were analyzed using visible-near infrared (VIS-NIR) spectroscopy. The objective of this study was to develop and validate a predictive model of oat quality by VIS-NIR spectroscopy. A total of 200 oat samples were collected from domestic and import markets. Reflectance spectra, moisture, protein, fat, Fe, and K of oat samples were measured. Reflectance spectra were measured in the wavelength range of 400 - 2,500 nm at 2 nm intervals. The reflectance spectrum of an oat sample was measured after sample cell and reflectance plate spectrum measurement. Preprocessing methods such as normalization and $1^{st}$ and $2^{nd}$ derivations were used to minimize the spectroscopic noise. The partial-least-square (PLS) models were developed to predict chemical properties of oats using a commercial software package, Unscrambler. The PLS models showed the possibility to predict moisture, protein, and fat content of oat samples. The coefficient of determination ($R^2$) of moisture, protein, and fat was greater than 0.89. However, it was hard to predict Fe and K concentrations due to their low concentrations in the oat samples. The coefficient of determinations of Fe and K were 0.57 and 0.77, respectively. In future studies, the stability and practicability of these models should be improved by using a high accuracy spectrophotometer and by performing calibrations with a wider range of oat chemicals.