• 대한공업교육학회지
• /
• v.44 no.1
• /
• pp.23-51
• /
• 2019

The purpose of this study was to analysis school dropout of specialized vocational high school students using phenomenological research method. The interview for the research was carried out with 10 adolescents who dropped out specialized vocational high school from December 8 to 23, 2018. According to the result of the research, 31 themes were extracted from interviews with 10 research participants. And 10 theme clusters were categorized from these. And these clusters were divided into 3 domains : 'before school dropout', 'causes & process of school dropout, feeling about school dropout', 'after school dropout' Based on the finding of the study, major conclusions of this study were as follow: First, adolescents who dropped out specialized vocational high school suffered from hard school life, disappointing lead from teachers, stereotypical lesson. And they committed misdeeds, and had psychological difficulties. Some of them kept up the good relationship with their friends, teachers, parents, some of them did not. Some of them kept up the good relationship with their friends, teachers and parents, while some of them did not. Second, they chose dropout due to various different causes. The procedures of school dropout proceeded with comparative ease. The effect of dropout prevention program is very limited. The feeling they felt at the time of school dropout varied individually. Some adolescents who dropped out specialized vocational high school were satisfied while others were stressed out, regretting their decision. Third, they lived diligently working part-time jobs or preparing General Equivalency Diploma (GED) test after dropout. They experienced positive changes in their daily lives after dropout. But sometimes they experienced various difficulties and negative changes. Most of them had their goals, and they were preparing for them. Their expectation was low that their life will succeed if they returned to school. They wanted people to understand their decision about dropout. And multiple institutions are supporting adolescents who dropped out specialized vocational high school. They need practical support : Various information, activity for career experience, counseling etc.

• Journal of Food Hygiene and Safety
• /
• v.33 no.6
• /
• pp.417-426
• /
• 2018

Food preservatives are very important food additives for the biological and chemical safety of processed foods. The purposes of this study were to investigate Korean consumer's perception and information needs on food preservatives, to develop an educational booklet as a risk communication material on food preservatives, and to assess the educational effect of the developed booklet. To understand perception on food preservatives, a self-administered questionnaire survey was conducted by 381 parents having elementary school students at Seoul and Geoynggi area in Korea. Based on the survey results, brain storming of the authors along with consultation from the professionals, we developed a risk communication booklet about food preservatives. It was exposed to 35 parents of elementary school children, and their evaluation was collected by using a questionnaire and analyzed statistically. Respondents considered food safety (44.8%) as the most important factor while purchasing processed foods. They still perceived food additives as the most hazardous one (41.5%), and among those, food preservatives were the most concerned (45.9%). Total 67.7% of the respondents considered the consumption of food preservatives as hazardous or very hazardous. However, 90.6% of respondents did not have any educational experience about food additives and food preservatives. Based on their information needs, a science-based booklet consisting of the definition, classification, safety, intake, and management of food preservatives was developed. When the booklet titled as 'Food preservatives, Just Know Them!' was exposed to the parents via elementary school teacher, their negative perceptions on food additives and food preservatives were changed positively by increasing the understanding level on preservatives from 18.9% to 90.9% and obtaining 72.7% positive answers on their safety. Therefore, it could be used as an effective risk communication material on food preservatives.

• Journal of the Korean Electrochemical Society
• /
• v.22 no.3
• /
• pp.128-137
• /
• 2019

A lithium is the lightest metal on the earth. It has some attractive characteristics as a negative electrode material such as a low reduction potential (-3.04 V vs. SHE) and a high theoretical capacity ($3,860mAh\;g^{-1}$). Therefore, it has been studied as a next generation anode material for high energy lithium batteries. The thin lithium electrode is required to maximize the efficiency and energy density of the battery, but the physical roll-press method has a limitation in manufacturing thin lithium. In this study, thin lithium electrode was fabricated by electrodeposition under various conditions such as compositions of electrolytes and the current density. Deposited lithium showed strong relationship between process condition and its characteristics. The concentration of electrolyte affects to the shape of deposited lithium particle. As the concentration increases, the shape of particle changes from a sharp edged long one to a rounded lump. The former shape is favorable for suppressing dendrite formation and the elec-trode shows good stripping efficiency of 92.68% (3M LiFSI in DME, $0.4mA\;cm^{-2}$). The shape of deposited particle also affected by the applied current density. When the amount of current applied gets larger the shape changes to the sharp edged long one like the case of the low concentration electrolyte. The combination of salts and solvents, 1.5M LiFSI + 1.5M LiTFSI in DME : DOL [1 : 1 vol%] (Du-Co), was applied to the electrolyte for the lithium deposition. The lithium electrode obtained from this electrolyte composition shows the best stripping efficiency (97.26%) and the stable reversibility. This is presumed to be due to the stability of the surface film induced by the Li-F component and the DOL effect of providing film flexibility.

• Korean Journal of Environment and Ecology
• /
• v.33 no.4
• /
• pp.453-461
• /
• 2019

This study was conducted to monitor the soil characteristics and growth of Pinus densiflora and to determine the effect of soil characteristics on growth rate five years after an ecological restoration project in Baekdudaegan ridge including Ihwaryeong, Yuksimnyeong, and Beoljae sites. The ecological restoration project was executed with the forest of P. densiflora in 2012-2013. In April 2018, we collected soil samples from each site and measured the height and the diameter at breach height (DBH) of P. densiflora. Although there was no significant change of soil pH compared to the early stage of restoration (one year after the project), it was high in Ihwaryeong, and Beoljae with values of 7.7 and 6.4, respectively. Also, the organic matter decreased by 70-80%, and the available phosphorus (P) was unchanged in three restoration sites. The decreased organic matter can be attributed to restriction of inflow and thus decomposition of litter in the early stage after the restoration. The tree height growth rate ($m\;yr^{-1}$) of P. densiflora in Yuksimnyeong was the highest at 1.02, followed by Beolja at 0.75 and Ihwaryeong at 0.17. The height growth rate showed negative relationships with soil pH and cations, including Na and Ca concentrations and a positive relationship with available phosphate. The low growth rate in the Ihwaryeong site, in particular, might result from the poor nutrient availability due to high soil pH and the decrease in water absorption into the root due to high Na and Ca concentrations. The substantial reduction of organic matter after five years indicates that the need for soil improvement using chemical fertilizer and biochar.

• Journal of Korea Water Resources Association
• /
• v.52 no.5
• /
• pp.349-360
• /
• 2019

The purpose of this study is to evaluate the stream flow and water quality (SS, T-N, and T-P) behavior of Nakdong river basin ($23,609.3km^2$) by simulating the dam and weir operation scenarios using SWAT (Soil and Water Assessment Tool). The operation senarios are the simultaneous release for all dam and weirs (scenario 1), simultaneous release for all weirs (scenario 2), and sequential release for the weirs with one month interval from upstream weirs (scenario 3). Before evaluation, the SWAT was calibrated and validated using 11 years (2005-2015) daily multi-purpose dam inflow at 5 locations (ADD, IHD, HCD, MKD, and MYD), multi-function weir inflow at 7 locations (SHW, GMW, CGW, GJW, DSW, HCW, and HAW), and monthly water quality monitoring data at 6 locations (AD-4, SJ-2, EG, HC, MK-4, and MG). For the two dam inflow and dam storage, the Nash-Sutcliffe efficiency (NSE) was 0.56~0.79, and the coefficient of determination ($R^2$) was 0.68~0.90. For water quality, the $R^2$ of SS, T-N, and T-P was 0.64~0.79, 0.51~0.74, and 0.53~0.72 respectively. For the three scenarios of dam and weir release combination suggested by the ministry of environment, the scenario 1 and 3 operations were improved the stream water quality (for T-N and T-P) within the 3 months since the time of release, but it showed the negative effect for 3 months after compared to scenario 2.

• Journal of Bio-Environment Control
• /
• v.30 no.1
• /
• pp.85-93
• /
• 2021

In hydroponic cultivation, in order to investigate the change of lettuce growth and physiologically active substances through CO2 tablet treatment in nutrient solution, we used a solid carbonated tablets commercially available in the Netherlands. The experiment consisted of 0.5-fold, 1-fold, and 2-fold treatment groups with no treatment as a control. As a result, the atmospheric CO2 concentration in the chamber after CO2 tablet treatment showed the highest value at 472.2 µL·L-1 in the 2-fold treatment zone immediately after treatment, and the pH in the nutrient solution decreased the most to pH 6.03 in the 2-fold treatment zone. After that, over time, the CO2 concentration and pH recovered to the level before treatment. Leaf width and leaf area of lettuce showed the highest values of 17.1cm and 1067.14 ㎠ when treated 2-fold with CO2 tablet, while fresh weight and dry weight of the above-ground part were highest at 63.87 g and 3.08 g in 0.5-fold treatment. The root length of lettuce was the longest (28.4 cm) in the control, but there was no significant difference in the fresh weight and the dry weight among the treatments. Apparently, it was observed that the root length of the lettuce was shortened by CO2 tablet treatment and a lot of side roots occurred. In addition, there was a growth disorder in which the roots turned black, but it was found that there was no negative effect on the growth of the above-ground part. As a result of analyzing the bioactive compounds of lettuce by CO2 tablet treatment, chlorogenic acid and quercetin were detected. As a result of quantitative analysis, chlorogenic acid increased by 249% compared to the control in 1-fold treatment, but quercetin decreased by 37%. As a result of comparing the DPPH radical scavenging ability showing antioxidant activity, the control and 0.5-fold treatment showed significantly higher values than the 1-fold and 2-fold treatments. This suggests that carbonated water treatment is effective in increasing the growth and bioactive compounds of hydroponic lettuce.

• (The)Study of the Eastern Classic
• /
• no.70
• /
• pp.495-524
• /
• 2018

This study investigated the literary theory of Jang Jiyeon and his compilation consciousness of the historical biography, and based on this, the study examined the aspect and characteristic of the personage adoption of "Ilsayusa". To figure out the characteristic of "Ilsayusa", this study attempted to investigate the Jang Jiyeon's cognition on epic literature first. Jang Jiyeon had interest in the historical biography in his early days. But he clearly expressed the negative position about the novels which had been handed down from old times, mentioning about their harmful effect, even though they were in a big popularity. The good readings he thought was supposed to be helpful for person's work, study, personality and even the custom, so it is thought that the compilation of "Ilsayusa" was planned as a part of a usefulness to help readers' actual lives by summarizing Jang Jiyeon's philosophy as the form of a historical biography of personages who had actually existed. The direct motivation and the awareness of the problem to compile "Ilsayusa" could be confirmed by the postscript he left. Pointing that Joseon's policy of appointing persons of ability resulted in the loss of the nation, Jang Jiyeon paid attention to the classical scholars from low class, people from under middle class and the local figures in Hamgyeongdo and Pyeongando in the process of compiling "Ilsayusa". Along with this, a kind of a sense of duty that the old heritage must be examined by descendents was manifested as the compilation of "Ilsayusa". Through this, Jang Jiyeon tried to show the good model to the readers of "Ilsayusa" what the way of living would be for raising their volition and keeping the fundamentals. The tendency and characteristic of compiling personages in "Ilsayusa" could be sorted in a few ways as written below. First, it includes all kinds of all actually existed episodes while he was collecting various historical biographies published before. Second, it includes the new kinds of personages paying particular attention to figures of middle class and commoners. Third, it compiled the female figures in a great volume and described new model of woman. Fourth, for areas, it has episodes of all areas in the nation including Pyeongando and Hamgyeongdo. Thinking about all the discussion above, we could estimate that "Ilsayusa" is the definitive edition of these kinds of books which inherited all performances of the biographical literature in better way, which had been accomplished in 19th century.

• Journal of Bio-Environment Control
• /
• v.30 no.1
• /
• pp.1-9
• /
• 2021

This study was conducted to examine the changes of photosynthesis, growth, chlorophyll contents and functional material contents in light intensity and EC concentration of wild baby leaf vegetable, Indian lettuce (Lactuca indica L. cv. 'Sunhyang') in DFT hydroponics. The cultivation environment was 25±1℃ of temperature and 60±5% of relative humidity in growth system. At 14 days after sowing, combination effect of light intensity (Photosynthetic Photon Flux Density (PPFD 100, 250, 500 µmol·m-2·s-1) and EC level (EC 0.8, 1.4, 2.0 dS·m-1) of nutrient solution was determined at the baby leaf stage. The photosynthesis rate, stomatal conductance, transpiration rate and water use efficiency of Indian lettuce increased as the light intensity increased. The photosynthesis rate and water use efficiency were highest in PPFD 500-EC 1.4 and PPFD 500-EC 2.0 treatment. The chlorophyll content decreased as the light intensity increased, but chlorophyll a/b ratio increased. Leaf water content and specific leaf area decreased as light intensity increased and a negative correlation (p < 0.001) was recognized. Plant height was the longest in PPFD 100-EC 0.8 and leaf number, fresh weight and dry weight were the highest in PPFD 500-EC 2.0. Anthocyanin and total phenolic compounds were the highest in PPFD 500-EC 1.4 and 2.0 treatment, and antioxidant scavenging ability (DPPH) was high in PPFD 250 and 500 treatments. Considering the growth and functional material contents, the proper light intensity and EC level for hydroponic cultivation of Indian lettuce is PPFD 500-EC 2.0, and PPFD 100 and 250, which are low light conditions, EC 0.8 is suitable for growth.

• The Journal of the Korea Contents Association
• /
• v.21 no.3
• /
• pp.529-540
• /
• 2021

This study is a test of gender differences between the importance of basic psychological needs and the components of love. The need for research is to verify the relationship between need and love. The purpose of this study is to serve as basic data for preparing a solution to the relationship between lovers and promoting love. Research participants targed a total of 193couples unmarried love couples, 386 person living in Seoul and Gyeonggi metropolitan areas. For the research tools, the basic psychological needs importance scale and components of love scale had been used. Regarding the analysis of the data, as a statistical analysis using SPSS 22, the t-verification, the correlation analysis, and the regression analysis method had been carried out. As a result of the analysis, regarding the importance of the basic psychological needs, regarding the relationship, the females were meaningfully (t=-3.528, p<.01) higher than the males. And, among components of love, regarding the passion and the commitment, the males were meaningfully (t=3.588, p<.001) higher than the females. And, regarding the correlations between the main variables, it appeared that the basic psychological needs importance of the males has a correlation with the components of love. And, regarding the females, it appeared that, among the basic psychological needs importance, only the relationship and the capability have the relationships with the components of love. Regarding the influence of the basic psychological needs importance on the component of love, it appeared that the relationship need importance of the males has a positive (+) influence on the component of love. And, regarding the autonomy need of the males, it appeared that, among the component of love, it has a negative (-) influence on the passion and the commitment. Regarding the females, it appeared that, differently from the males, only the need for a relationship has a positive (+) influence on the components of love. It was found that women's relationship needs had a positive effect on the components of love, but women's desire for autonomy did not affect the components of love, unlike men. Therefore, the importance of the basic psychological needs of love couples influenced the love relationship, and the relationship between the variables showed gender differences. If love couple understands and meets the importance of each other different basic psychological needs when a conflict arises, it will be a helpful resource for resolving conflict and promoting love.

• The Journal of Korean Society for Radiation Therapy
• /
• v.33
• /
• pp.127-135
• /
• 2021

Purpose : The purpose of the study is to evaluate the efficiency of Vertical MLC VMAT plan(VMV plan) Using 273° and 350° collimator angle compare to Complemental MLC VMAT plan(CMV plan) using 20° and 340° collimator angle for nasopharyngeal carcinoma. Materials & Methods : Thirty patients treated for nasopharyngeal carcinoma with the VMAT technique were retrospectively selected. Those cases were planned by Eclipse, PO and AcurosXB Algorithm with two 6MV 360° arcs and Each arc has 273° and 350° of collimator angle. The Complemental MLC VMAT plans are based on existing treatment plans. Those plans have the same parameters of existing treatment plans but collimator angle. For dosimetric evaluation, the dose-volumetric(DV) parameters of the planning target volume (PTV) and organs at risk (OARs) were calculated for all VMAT plans. MCSv(Modulation complexity score of VMAT), MU and treatment time were also compared. In addition, Pearson's correlation analysis was performed to confirm whether there was a correlation between the difference in the MCSv and the difference in each evaluation index of the two treatment plans. Result : In the case of PTV evaluation index, the CI of PTV_67.5 was improved by 3.76% in the VMV Plan, then for OAR, the dose reduction effect of the spinal cord (-14.05%) and brain stem (-9.34%) was remarkable. In addition, the parotid glands (left parotid : -5.38%, right : -5.97%) and visual organs (left optic nerve: -4.88%, right optic nerve: -5.80%, optic chiasm : -6.12%, left lens: -6.12%, right lens: -5.26%), auditory organs (left: -11.74%, right: -12.31%) and thyroid gland (-2.02%) were also confirmed. The difference in MCSv of the two treatment plans showed a significant negative (-) correlation with the difference in CI (r=-0.55) of PTV_54 and the difference in CI (r=-0.43) of PTV_48. Spinal cord (r=0.40), brain stem (r=0.34), and both salivary glands (left: r=0.36, right: r=0.37) showed a positive (+) correlation. (For all the values, p<.05) Conclusion : Compared to the CMV plan, the VMV plan is considered to be helpful in improving the quality of the treatment plan by allowing the MLC to be modulated more efficiently