• Journal of the Korean Society of Child Welfare
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• no.59
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• pp.209-234
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• 2017

This study viewed schools as a cause of students dropping out and posited that dropping out of high school would vary depending on the characteristics and influencing factors of the school from which students were dropping out. Therefore, focusing on schools, we longitudinally investigated the change patterns of school dropout across high schools in the country, and the types of changes in dropping out of high school. In addition, we predicted the general characteristics of schools according to the type of school students were dropping out from, looked at the changes in the major factors (i.e., school violence and school counseling) affecting school dropout, and reviewed schools' long-term efforts and outcomes in relation to school dropout. For this purpose, KERIS EDSS's "Secondary School Information Disclosure Data" were used. The final model included data collected five years20122016) from high schools across the country. The results were as follows. First, in order to examine the longitudinal change patterns of dropping out of high schools, a latent growth models analysis was conducted, and it revealed that, as time passed, the dropout rate decreased. Second, growth mixture modeling was used to explore types according to the change patterns of the school students were dropping out from. The results showed three types: the "remaining in school" type, the "gradually decreasing school dropout" type, and the "increasing school dropping out". Third, the multinomial logistic regression was conducted to predict the general characteristics of schools by type. The results showed that public schools, vocational schools, and schools with a large number of students who have below the basic levels in Korean, English and mathematics were more likely to belong to the "increasing school dropout" type. Further, the larger the total number of students, the higher the probability of belonging to the "remaining in school" type or the "gradually decreasing school dropout" type. Lastly, growth mixture modeling was used to analyze the trend of school violence and school counseling according to the three types. The focus was on the "gradually decreasing school dropout" type. In the case of the "gradually decreasing school dropout" type, it was found that as time passed, the number of school violence cases and the number of offenders gradually decreased. In addition, in terms of change in school counseling the results revealed that the number of placement of professional counselors in schools increased every year and peer counseling was continuously promoted, which may account for the "gradually decreasing school dropout" type.

• Food Engineering Progress
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• v.14 no.2
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• pp.85-91
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• 2010

In the food process, twist screen is widely used to divide particles on the basis of size. As screen equipped in the twist screen perfoms an important part in the particle size distribution mechanism, the contact area of screen and particles, retention time of particles on the screen, mesh and string thickness of screen and the flow pattern of particles on the screen are major points of the separation efficiency. To improve the separation efficiency, increase the retention time and control the flow pattern of particles, screen frame dam and spiral blockage are installed on the sieve of twist screen ${\emptyset}$ 1200 and ${\emptyset}$ 1500. Twist screen ${\emptyset}$ 1500 with frame dam treated similar separation capacity, 37% higher separation ratio and less non-separated particles of product output 1 than general twist screen. Twist screens with frame dam and spiral blockage showed less treatment capacity, three times higher division ratio and entire separation than general twist screen.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.420-428
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• 2009

In this study, the variation of 20 Pinus thunbergii isolates of F. circinatum from 2 damaged sites in Jeju-Island were compared with a known Fusarium circinatum using molecular biological techniques. Two- and four-year-old seedlings of Pinus rigida${\times}$Pinus x rigitaeda and two-, three- and six-year-old seedlings of P. thunbergii were inoculated with one of the most virulent isolates, FT-7, to determine differences in susceptibility. In site 1 (FT), 13 isolates of F. circinatum were isolated from 14 individuals and in site 2 (FS), 7 isolates of F. circinatum were isolated from 9 individuals. No difference was found in the sequences of the internal transcribed spacer (ITS) region of the ribosomal RNA genes in the FS and FT isolates, and also even in the known isolate of F. circinatum, FE 1-1. However, the ITS sequences of the FS and FT isolates differed from those of a fungus, Botrytis cinerea. Two-year-old seedlings of P. rigida${\times}$P. x rigitaeda showed higher susceptibility (93.3% of mortality) than four-year-old ones. Three-year-old seedlings of P. thunbergii showed the highest susceptibility (66.7% of mortality) compared to those at other ages in the same species. We found a positive correlation between basal diameter and lesion length in the seedlings of P. rigida${\times}$P. x rigitaeda ($R^2=0.66$) and P. thunbergii (p < 0.0001), respectively. There were significant differences in susceptibility by the age of seedlings in each of P. rigida${\times}$P. x rigitaeda (p < 0.0001) and P. thunbergii (p < 0.0001) based on lesion length.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.268-276
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• 2018

BACKGROUND: In the month of January 2018, fine dust alerts and warnings were issued 36 times for $PM_{10}$ and 81 times for PM2.5. Air quality is becoming a serious issue nation-wide. Although interest in air-purifying plants is growing due to the controversy over the risk of chemical substances of regular air-purifying solutions, industrial spread of the plants has been limited due to their efficiency in air-conditioning perspective. METHODS AND RESULTS: This study aims to propose a vegetation-based bio-filter system that can assure total indoor air volume for the efficient application of air-purifying plants. In order to evaluate the quantitative performance of the system, time-series analysis was conducted on air-conditioning performance, indoor air quality, and comfort index improvement effects in a lecture room-style laboratory with 16 persons present in the room. The system provided 4.24 ACH ventilation rate and reduced indoor temperature by $1.6^{\circ}C$ and black bulb temperature by $1.0^{\circ}C$. Relative humidity increased by 24.4% and deteriorated comfort index. However, this seemed to be offset by turbulent flow created from the operation of air blowers. While $PM_{10}$ was reduced by 39.5% to $22.11{\mu}g/m^3$, $CO_2$ increased up to 1,329ppm. It is interpreted that released $CO_2$ could not be processed because light compensation point was not reached. As for the indoor comfort index, PMV was reduced by 83.6 % and PPD was reduced by 47.0% on average, indicating that indoor space in a comfort range could be created by operating vegetation-based bio-filters. CONCLUSION: The study confirmed that the vegetation-based bio-filter system is effective in lowering indoor temperature and $PM_{10}$ and has positive effects on creating comfortable indoor space in terms of PMV and PPD.

• Journal of Nutrition and Health
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• v.52 no.1
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• pp.36-46
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• 2019

Purpose: This study evaluated amounts of physical activity and sedentary behavior patterns in older adults using an accelerometer and physical activity diary. Methods: Forty-nine older adults (male 26, female 23) participated in this study. They wore a triaxial accelerometer (ActiGraph wGT3X-BT) for one week and wrote a physical activity diary concurrently for three days. Amounts of physical activity, sedentary behavior patterns, and percentage of meeting the World health organization (WHO) physical activity guidelines were analyzed using an accelerometer. In addition, the contents recorded in the physical activity diary were reclassified to 18 levels and the average daily times spent on each level and physical activity level (PAL) were calculated. Results: The subjects were sitting more than half of the day except for bedtime and shower time (59.2%). The numbers of prolonged ${\geq}30$, 40 minutes sedentary bouts were significantly higher in males ($3.10{\pm}1.34$, $1.78{\pm}1.09$, respectively) than in females ($2.34{\pm}1.22$, $1.32{\pm}1.07$, respectively) and the number of breaks per sedentary hour was significantly less in males ($5.74{\pm}0.89$) than in females ($6.44{\pm}0.71$). Among the activities corresponding to sedentary behavior surveyed by the physical activity diary, only the amount of time spent 'resting, speaking and watching TV' showed a significant correlation with the sedentary behavior pattern measured by the accelerometer. The persistence of sedentary behavior was interrupted primarily when low intensity activity was performed. Only 22.4% of the subjects met WHO physical activity guidelines. Conclusion: Based on these results, the physical activity guidelines for older adults should be developed that reflects the appropriate strength, including low activity level and maintenance time of moderate to vigorous physical activity.

• Journal of Life Science
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• v.29 no.3
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• pp.337-344
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• 2019

The free radical scavenging, cytotoxic effects, and flavonoid content of fractions from Lycopus lucidus Turcz leaves were here investigated. The flavonoid contents of 85% methanol (MeOH) and n-butanol (BuOH) fractions of the leaves were 41.5 mg/g and 77.2 mg/g, respectively. In DPPH and ABTs+ assays, 85% MeOH and n-BuOH fractions from the L. lucidus Turcz leaves had a greater scavenging effect (p<0.05). The n-BuOH fraction (0.5 mg/ml concentration) had scavenging effects of 88% and 92% in the DPPH and ABTs+ assays, respectively (p<0.05). Cell viability tests showed that treatment with L. lucidus Turcz leaf fractions caused cytotoxicity in the growth of AGS, HT-29, and HT-1080 cancer cells. Of the different fractions, the 85% MeOH sample displayed the highest cytotoxic activity; the $IC_{50}$ values of this fraction against AGS, HT-1080, and HT-29 cancer cells were 0.03 mg/ml, 0.14 mg/ml, and 0.16 mg/ml, respectively. These biological results indicate that the n-BuOH fraction was more effective in anti-oxidant activity while the 85% MeOH fraction was stronger in cytotoxic effects, and they suggest that these two fractions from L. lucidus Turcz leaves may contain valuable bioactive compounds, such as flavonoids.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.283-290
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• 2018

BACKGROUND: Pesticide residue analysis is an essential activity in order to establish the food safety of agricultural products. Analytical approaches to the food safety are required to meet internationally the guideline of Codex (Codex Alimentarius Commission, CAC/GL 40). In this study, we developed a liquid chromatograph-tandem mass spectrometer (LC-MS/MS) method to determine the herbicide clopyralid in food matrixes. METHODS AND RESULTS: Clopyralid was extracted with aqueous acetonitrile containing formic acid and the extracts were mixed in a citrate buffer consisted of magnesium sulfate anhydrous, NaCl, sodium citrate dihydrate and disodium hydrogencitrate sesquihydrate followed by centrifugation. The supernatants were filtered through a nylon membrane filter and used for the analysis of clopyralid. The method was validated by accuracy and precision experiments on the samples fortified at 3 different levels of clopyralid. LC-MS/MS in positive mode was employed to quantitatively determine clopyralid in the food samples. Matrix-matched calibration curves were inearranged from 0.001 to 0.25 mg/kg with r2 > 0.994. The limits of detection and quantification were determined to be 0.001 and 0.01 mg/kg, respectively. There covery values of clopyralid for tified at 0.01 mg/kg in the control samples ranged from approximately 82 to 106% with relative standard deviations below 2 0%. CONCLUSION: The method developed in this study meets successfully the Codex guideline for pesticide residue analysis in food samples. This, the method could be applicable to determine pesticides in foods produced domestically and internationally.

• Journal of Cadastre & Land InformatiX
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• v.48 no.2
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• pp.79-98
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• 2018

The purpose of this study is to suggest a model analysing spatio-temporal characteristics of the civil complaints for the officially assessed land price based on big data mining. Specifically, in this study, the underlying reasons for the civil complaints were found from the spatio-temporal perspectives, rather than the institutional factors, and a model was suggested monitoring a trend of the occurrence of such complaints. The official documents of 6,481 civil complaints for the officially assessed land price in the district of Jung-gu of Incheon Metropolitan City over the period from 2006 to 2015 along with their temporal and spatial poperties were collected and used for the analysis. Frequencies of major key words were examined by using a text mining method. Correlations among mafor key words were studied through the social network analysis. By calculating term frequency(TF) and term frequency-inverse document frequency(TF-IDF), which correspond to the weighted value of key words, I identified the major key words for the occurrence of the civil complaint for the officially assessed land price. Then the spatio-temporal characteristics of the civil complaints were examined by analysing hot spot based on the statistics of Getis-Ord $Gi^*$. It was found that the characteristic of civil complaints for the officially assessed land price were changing, forming a cluster that is linked spatio-temporally. Using text mining and social network analysis method, we could find out that the occurrence reason of civil complaints for the officially assessed land price could be identified quantitatively based on natural language. TF and TF-IDF, the weighted averages of key words, can be used as main explanatory variables to analyze spatio-temporal characteristics of civil complaints for the officially assessed land price since these statistics are different over time across different regions.

• Korean Journal of Poultry Science
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• v.45 no.4
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• pp.245-252
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• 2018

This study investigated the effect of LED light wavelength (color) on reproductive hormones and egg production of brown laying hens raised on floor. Red, blue, green and white colors of LED light were four treatments with four pens per treatment. One hundred forty four Hy-line brown laying hens (47 wks old) were allocated in a floor pen for six weeks trial. Egg production, egg quality, yolk cholesterol and hormones ($17{\beta}$-estradiol, progesterone) concentrations in plasma and oviduct were analyzed. Egg production of red group was higher (P<0.01) than that of green group. Haugh unit of eggs from red group was higher (P<0.01) than that of blue and green groups. Egg weight of green group was heavier (P<0.05) than that of red group. Shell of blue group was stronger (P<0.05) than that of red and white groups. Shell color of white group was browner (P<0.01) than that of blue and green groups. Yolk cholesterol of red group was higher (P<0.01) than that of others. Plasma $17{\beta}$-estradiol of red group was higher (P<0.05) than that of others at $3^{rd}$ week, but that of white group was highest (P<0.05) at $6^{th}$ week. Oviduct progesterone of green group was higher (P<0.01) than that of others. The result showed that the LED colors affect the reproductive hormone concentrations, egg production, egg weight and egg quality. This study suggested that red LED would be the most appropriate color for floor raising brown laying hens to sustain the egg production when it begins to decline with aging.

• Korean Journal of Heritage: History & Science
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• v.47 no.1
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• pp.116-133
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• 2014

The memorial stones of Sumanotap were known to have been sequentially produced in 1719, 1773, 1874, 1653, 1874. However, after examining the chronological era (年號) and sexagesimal cycle (干支), it was found that the second and fourth memorial stones were both recorded in 1713. The reason why the records of the same period were divided into two is assumed that since the subject to repair was divided into main structure and flagpole of the temple, and it was recorded per each monk in charge and donator. On the fifth tablet of the memorial stone of Sumanotap contains all the names of monks who were in charge of repairing Sumanotap as well as the names of common donators. These people are not verified in detail though, through comparing the Buddhist names on the third memorial stone with Buddhist paintings and painting records, 12 monks were identified to be in the same names. Generally, they were active in Gangwon province, Gyeongsang province, Seoul and Gyeonggi province in the late 19th century and even after the Sumanotap repair, they took up other duties of various temples. The most notable name among the donators recorded in the memorial stones of Sumanotap was Kim Jwageun. He was the donator for the chest of gold and silver that was enshrined in the pagoda in 1874. His name was recorded with Mrs. Yang from Cheongsin and, at that time, was known just as a donator. However, actually, the donator was not Kim Jwageun but his mistress Mrs. Yang who used to be a gisaeng, called Na-hap and was from Naju. Kim Jwageun deceased in 1869 already. It is exceptional that Mrs. Yang who were the mistress of the prime minister Kim Jwageun personally participated in the Buddhist event in which king, queen, mothers of king and queen, noblewoman participated. Besides, the event of Sumanotap repair was carried out by royal family in order to celebrate the hundredth day of the prince, Sunjong and his grandfather, Heungseon Daewongun did not participate for political reason. In this situation, the domination of Mrs. Yang is considered remarkable. Meanwhile, the temples that frequently appeared among the 10 temples recorded in the memorial stone of Sumanotap are Gakhwa-sa temple in Bonghwa-gun, Gyeongsangbuk-do and Bodeok-sa temple in Yeongwolgun, Gangwon-do. Gakhwa-sa temple was a temple where the historical achievements were kept so was under the government's control. Bodeok-sa temple was the buddhist temple praying for the soul of the Danjong buried in the tomb and was managed by the government. Therefore, the face these two temples participated in the Sumanotap repair proves that Sumanotap was repaired by the supports form these two temples and the stature of Sumanotap at that time was as high as the temples where the historical achievements are store or the royal buddhist temples for praying for ancestors' souls.