• Journal of dental hygiene science
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• v.6 no.3
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• pp.147-152
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• 2006

The purpose of this study was to help decrease turnover and to make full use of dental hygienists and to help improve management by managers. After relevant literature and data were reviewed, a survey was conducted on dental hygienists, who worked at dental institutes in different areas, for about four months from September through December, 2004, to find out their turnover intention and job satisfaction level. When the collected data were analyzed, the following findings were given: 1. The collective average of the dental hygienists investigated in job satisfaction was $3.30{\pm}0.70$. By area, they expressed the best satisfaction at a clear role factors with a mean of $3.53{\pm}0.73$, and they were pleased with wages factors and promotion factors the least with an average of $3.14{\pm}0.70$ and $3.18{\pm}0.80$. 2. The collective average of the dental hygienists investigated in turnover intention was $3.23{\pm}0.77$. As for connections between general characteristics and turnover intention, By age, those who aged in 21 and 25 were most intended(p < 0.001). The unmarried dental hygienists were more intended than the married ones(p < 0.001). By type of hospital, those who worked at dental clinics were most intended(p< 0.01). By career, those who had worked at one to three years were intended the most(p < 0.001), and as to the length of service at current work places, those who had worked at their current work places for one to three years were intended the most(p < 0.001). By monthly mean pay, those whose pay ranged from 1.3 to 1.6 million won found their turnover most intended(p< 0.01). 3. Regarding correlation among turnover intention and job satisfaction were both inversed correlationship, and wages factor(r = -0.249, p < 0.01) and interrelationship factors(r = -0.218, p < 0.01) had a strong correlation to turnover intention, and clear role factors had a strong correlation to job contents factors by job satisfaction(r = 0.612, p < 0.01), and job satisfaction factors had a strong correlation to job contents factors(r = 0.759, p < 0.01).

• Journal of the Korean earth science society
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• v.38 no.4
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• pp.283-292
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• 2017

In this study, the empirical models were established to estimate the concentrations of surface-level $PM_{2.5}$ over Seoul, Korea from 1 January 2012 to 31 December 2013. We used six different multiple linear regression models with aerosol optical thickness (AOT), ${\AA}ngstr{\ddot{o}}m$ exponents (AE) data from Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Terra and Aqua satellites, meteorological data, and planetary boundary layer depth (PBLD) data. The results showed that $M_6$ was the best empirical model and AOT, AE, relative humidity (RH), wind speed, wind direction, PBLD, and air temperature data were used as input data. Statistical analysis showed that the result between the observed $PM_{2.5}$ and the estimated $PM_{2.5}$ concentrations using $M_6$ model were correlations (R=0.62) and root square mean error ($RMSE=10.70{\mu}gm^{-3}$). In addition, our study show that the relation strongly depends on the seasons due to seasonal observation characteristics of AOT, with a relatively better correlation in spring (R=0.66) and autumntime (R=0.75) than summer and wintertime (R was about 0.38 and 0.56). These results were due to cloud contamination of summertime and the influence of snow/ice surface of wintertime, compared with those of other seasons. Therefore, the empirical multiple linear regression model used in this study showed that the AOT data retrieved from the satellite was important a dominant variable and we will need to use additional weather variables to improve the results of $PM_{2.5}$. Also, the result calculated for $PM_{2.5}$ using empirical multi linear regression model will be useful as a method to enable monitoring of atmospheric environment from satellite and ground meteorological data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.262-268
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• 2017

The energy consumption of buildings is approximately 20.5% of the total energy consumption, and the interest in energy efficiency and low consumption of the building is increasing. Several studies have performed energy analysis and evaluation. Energy analysis and evaluation are effective when applied in the initial design phase. In the initial design phase, however, the energy performance is evaluated using general level information, such as glazing area and surface area. Therefore, the evaluation results of the detailed design stage, which is based on the drawings, including detailed information of the materials and facilities, will be different. Thus far, most studies have reported the analysis and evaluation at the detailed design stage, where detailed information about the materials installed in the building becomes clear. Therefore, it is possible to improve the accuracy of the energy environment analysis if the energy environment information generated during the life cycle of the building can be established and accurate information can be provided in the analysis at the initial design stage using a probability / statistical method. On the other hand, historical data on energy use has not been established in Korea. Therefore, this study performed energy environment analysis to construct the energy environment historical data. As a result of the research, information classification system, information model, and service model for acquiring and providing energy environment information that can be used for building lifecycle information of buildings are presented and used as the basic data. The results can be utilized in the historical data management system so that the reliability of analysis can be improved by supplementing the input information at the initial design stage. If the historical data is stacked, it can be used as learning data in methods, such as probability / statistics or artificial intelligence for energy environment analysis in the initial design stage.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.556-566
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• 2014

In this study, we collected 29 Kenaf (Hibiscus cannabinus L.) genetic resources from 10 countries to confirm the possibility of the introduction into Korea. The Kenaf (Hibiscus cannabinus L.) has the broad industrial use like feed and the 5 times more strong $CO_2$ absorption capacity compared to general plant. So recently it is considered as a good industrial source. We analyzed ecotype, growth and development, yield and feed value of collected resources. They were divided into 3 groups depending on flowering time, early maturing type blooming in early July, mid-late maturing type blooming from end of August to early September and late maturing type blooming in end of October. Early maturing type could get fruitful seed but dropped yield (average 7,895 kg/10a) and late maturing type could get high yield (average 12,572 kg/10a) but deletion. The other side mid-late maturing type could get yield over a certain level (average 11,207 kg/10a) and fruitful seed was ensured. The yields analyzed by resources indicated that K12 (Hongma 300) collected in China, K25 from India, K22 from Russia and K21 (Khonkaen 60) variety from China were more than 13,500 kg per 10a. Feed value of early maturing type had inclined to more better than other types, but like dry digestible matter (DDM) and dry matter intake (DMI) of some late maturing types like K12, K21, K22 which had a high yielding ability were more better than that of early maturing types'. So relative feed value (RFV) which considered comprehensive item for feed value were indicated K21 was 102.5, K12 was 116.2 and K22 was 120.2. 'Jangdae' the variety developed in Korea which could complement of other types' had a good quality for yield 10,975 kg/10a and 12.5% crude protein content and 101.9 of the relative feed value. So we need to be taken power to collection of mid-late maturing types resources.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.308-314
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• 2011

This study surveyed and compared the temperatures established in display stands and food surfaces for cold and frozen foods in large discount stores in Korea. The temperatures established in display stands for cold food ranged with $3.5{\pm}1.8^{\circ}C$ as mean, minimum and maximum were $0^{\circ}C$ and $7^{\circ}C$. However, the surface temperatures of cold food on sale ranged with $10.7{\pm}2.9^{\circ}C$ as a mean, minimum $4.6^{\circ}C$ and maximum $18.4^{\circ}C$. Totally, the surface temperature of cold food on sale was $7.2^{\circ}C$, as a mean, higher than established in display stands for cold food in large discount stores in Korea. 53% of the surveyed cold foods were more than $10^{\circ}C$ in surface temperature and only 47% was less than $10^{\circ}C$. The differences between temperatures were lowest in fruits, salads and vegetables, but highest in milk products. On the other hand, the temperatures established in display stands for frozen food showed a range with $-20.7{\pm}1^{\circ}C$ as a mean. However, the surface temperatures of frozen food on sale showed a range with $-15.4{\pm}5^{\circ}C$ as a mean, minimum $-28^{\circ}C$ and maximum $-4.6^{\circ}C$ (included defrosting). The surface temperatures of frozen food, frozen meats, frozen processed foods and ice creams were $-13.8^{\circ}C$, $-15.9^{\circ}C$, and $-16.8^{\circ}C$, respectively. Only 32.3% of surveyed frozen foods showed less than $-18^{\circ}C$ in surface temperature. In conclusion, the temperatures established on cold and frozen food display stands were less than those of cold and frozen food surfaces on sale. There was also much variation in food surface temperatures during cold and frozen food storage and sales. Therefore, a temperature management system technology use at the distribution level for cold and frozen foods will be developed.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.71-80
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• 2012

Vinca alkaloids produced from Catharanthus roseus are one of the most important natural product drugs in treatments of human cancers. These anticancer drugs are derived from coupling of the two monomeric indole alkaloids, catharanthine and vindoline. In order to investigate vindoline biosynthesis, tabersonine-$CD_3$ 1a is synthesized to use as a deuterium labeled precursor, which is distinguished clearly from the natural counterpart. We show that these deuterium labeled tabersonine 1a are successfully incorporated into the vindoline biosynthetic pathway to yield three deuterated vindoline intermediates. 16-Hydroxytabersonine-$CD_3$ (m/z 356) 2a, 16-Methoxytabersonine-$CD_3$ (m/z 370) 3a, 16-Methoxy-2,3-dihydro-3-hydroxytabersonine-$CD_3$ (m/z 388) 4a are produced from the cell suspension culture measured by UPLC/MS at 5 and 13 days after feeding tabersonine. The conversion rates from 1a to 2a and 2a to 3a are fast, whereas that from 3a to 4a is much slower. This indicates that the rate determining step among the first three vindoline biosynthesis is the last step. As a result of the slow conversion rate from 3a to 4a, the accumulation level of 16-Methoxytabersonine-$CD_3$ 3a is significantly increased up to 13 days. The accumulation ratio among 2a, 3a and 4a is 1, 2 and 0.1 at 5 days. However, the peaks of desacetoxyvindoline-$CD_3$ 5a, deacetylvindoline-$CD_3$ 6a and vindoline-$CD_3$ 7a are not found from the cell extracts even after 13 days of incubation which may indicate no presence of their corresponding enzymes.

• Korean Journal of Remote Sensing
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• v.35 no.6_2
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• pp.1117-1132
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• 2019

Forest covers 30% of the Earth's land area and plays an important role in global carbon flux through its ability to store much greater amounts of carbon than other terrestrial ecosystems. The Gross Primary Production (GPP) represents the productivity of forest ecosystems according to climate change and its effect on the phenology, health, and carbon cycle. In this study, we estimated the daily GPP for a forest ecosystem using remote-sensed data from Moderate Resolution Imaging Spectroradiometer (MODIS) and machine learning algorithms Support Vector Machine (SVM). MODIS products were employed to train the SVM model from 75% to 80% data of the total study period and validated using eddy covariance measurement (EC) data at the six flux tower sites. We also compare the GPP derived from EC and MODIS (MYD17). The MODIS products made use of two data sets: one for Processed MODIS that included calculated by combined products (e.g., Vapor Pressure Deficit), another one for Unprocessed MODIS that used MODIS products without any combined calculation. Statistical analyses, including Pearson correlation coefficient (R), mean squared error (MSE), and root mean square error (RMSE) were used to evaluate the outcomes of the model. In general, the SVM model trained by the Unprocessed MODIS (R = 0.77 - 0.94, p < 0.001) derived from the multi-sites outperformed those trained at a single-site (R = 0.75 - 0.95, p < 0.001). These results show better performance trained by the data including various events and suggest the possibility of using remote-sensed data without complex processes to estimate GPP such as non-stationary ecological processes.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.176-183
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• 2013

To explore hydrolysis methods for the efficient manufacture of sugar solutions from the freshwater alga Water-net (Hydrodictyon reticulatum, HR), acid hydrolysis, enzymatic hydrolysis, and combined hydrolysis (acid followed by enzymatic hydrolysis) were investigated. In the one-step acid hydrolysis, the reaction of 8% solids content using 2% sulfuric acid at $120^{\circ}C$ for 1 hour was desirable. In this case, glucose 27.44 g 100 g $DM^{-1}$ could be obtained from the HR-d13 samples. In the two-step acid hydrolysis, the primary hydrolysis (HR powder : 72% sulfuric acid = 1 g : 1.5 mL) was carried out for 1 hour at $60^{\circ}C$, and then the secondary hydrolysis was done for 1 hour at $120^{\circ}C$ after addition of distilled water 23.5 mL. In this case, glucose 35.11 g/100 g DM could be obtained from the HR-d13 samples. In the combined hydrolysis, 25% solids content using 2% hydrochloric acid were reacted for 1 hour at $120^{\circ}C$, and then citrate buffer and hydrolysis enzyme complexes (E1 1.0 mL+E2 0.2 mL $g^{-1}$ dried matter) were added and reacted for 1 - 2 days at $50^{\circ}C$. In this case, glucose 33.5 g 100 g $DM^{-1}$ could be obtained from the HR-d23+26 samples. In conclusion, combined hydrolysis was likely to be more useful saccharification method of HR biomass at a practical level, considering the glucose productivity, generation of fermentation-inhibiting substances (hydroxyl methyl furfural, furfural), and limited use of strong acid.

• Journal of Korea Port Economic Association
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• v.38 no.3
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• pp.105-131
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• 2022

Even after the improvement in 2019, UNCTAD's Liner Shipping Connectivity Index (LSCI), which evaluates the performance of the global container port market, has limited use. In particular, since the liner shipping connectivity index evaluates the performance based only on the distance of the relationship, the performance index combining the port attractiveness of calling would be more efficient. This study used the modified Huff model, the hub-authority algorithm and the eigenvector centrality of social network analysis, and correlation analysis for 2007, 2017, and 2019 data of Ocean-Commerce, Japan. The findings are as follows: Firstly, the port attractiveness of calling and the overall performance of the port did not always match. However, according to the analysis of the attractiveness of a port calling, Busan remained within the top 10. Still, the attractiveness among other Korean ports improved slowly from the low level during the study period. Secondly, Global container ports are generally specialized for long-term specialized inbound and outbound ports by the route and grow while maintaining professionalism throughout the entire period. The Korean ports continue to change roles from analysis period to period. Lastly, the volume of cargo by period and the extended port connectivity index (EPCI) presented in this study showed a correlation from 0.77 to 0.85. Even though the Atlantic data is excluded from the analysis and the ship's operable capacity is used instead of the port throughput volume, it shows a high correlation. The study result would help evaluate and analyze global ports. According to the study, Korean ports need a long-term strategy to improve performance while maintaining professionalism. In order to maintain and develop the port's desirable role, it is necessary to utilize cooperation and partnerships with the complimentary port and attract shipping companies' services calling to the complementary port. Although this study carried out a complex analysis using a lot of data and methodologies for an extended period, it is necessary to conduct a study covering ports around the world, a long-term panel analysis, and a scientific parameter estimation study of the attractiveness analysis.

• Journal of agricultural medicine and community health
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• v.29 no.1
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• pp.1-14
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• 2004

Objectives: We investigated the factors related to health examination behaviors, sociodemographic aspects and lifestyles of elderly persons with different social backgrounds, and compared sexual and regional differences in urban and rural elderlies. Methods: The total study subjects(464 individuals) from urban(236) and rural areas(228), recruited by a stratified cluster random sampling were interviewed and examined about their sociodemographic profiles, daily lifestyles, subjective health status, conditions concerning use of medical resources, hearing acuity, visual acuity and ADL(activity of daily living), and whether they receive health examination or not. For statistical analysis, Chi-square test was used for sexual and regional comparisons among the groups who have been given a health examination and the one who have not. Results: In urban areas, the rate of having underwent health examination was 54.5% in men and 46.9% in women, and in rural areas, it was 59.8% in men and 42.7% in women, showing its higher rate in men than in women in both areas. For regional differences between the group who have taken a health examination and the one who have not, there was a significant difference in terms of age, family pattern, current job, monthly household income, owning a house, drinking status, eating habit, subjective health status, whether they have taken outpatient medical service for the recent 3 months or not, anxiety for the health, and IADL conditions according to whether the community is rural or urban. In multiple regressions, the influential factors on the health examination behaviors were selected such as having their own house, their family doctor, amnesia, urinary incontinence and chronic disease in urban districts. But in rural districts, the variables were selected such as having or not of their family doctor, urinary incontinence, anxiety for the health, educational level, their own house and chronic disease. Conclusions: It is suggested that the approach to the health examination of an older patient requires substantial consideration of highly variable individual sociodemographic characteristics involving regional attributes as well as their daily life styles, subjective health status, status of performing health examination, physical health status and ADL conditions.