• Journal of Bio-Environment Control
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• v.32 no.3
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• pp.249-255
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• 2023

Korean melon (Cucumis melo L.) is grown mostly in Northeast Asia area, and as a fruit mainly produced in Korea, the yield per unit area continues to improve, but the cultivation method is limited to soil cultivation, so it is necessary to develop hydroponic cultivation technology for scale and labor-saving is needed. As the ratio of NO₃^- increased, the plant height, the leaf length, the leaf width, and the internode length became longer and larger. On the other hand, the SPAD value decreased. The lower the ratio of NO₃^-, the faster the female flower bloom, and there was no difference in fruit maturity between treatments. There was no difference in the shape of fruit according to the ratio of NO₃^-, and the hardness was higher as the ratio of NO₃^- was lower. The total yield from March to July was KM3 5,650 kg/10a and KM1 4,439 kg/10a, 27% higher in KM3 and, in particular, 36% higher in quantity from March to May, when Korean melon prices were high season. Therefore, it was judged that it would be appropriate to supply NO₃^- suitable for hydroponic cultivation of Korean melon, which was formalized in December and produced from spring, at the level of 6.5 to 10 me·L^-1.

• Journal of Korea Entertainment Industry Association
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• v.13 no.2
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• pp.197-205
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• 2019

This study was to compare arterial stiffness and hemodynamic responses between male smokers and non-smokers. This study also investigates the influences of smoking before exercise on arterial stiffness and hemodynamic responses. 24 male subjects of age 20-29 without history of cardiorespiratory disease were divided into smokers and non-smokers. Smokers had more than 5 years of smoking experience. In order to evaluate the effects of pre-exercise smoking, smokers were tested twice, once with a cigarette before the exercise and the other once without one. Data was collected from bio-impedance analysis, SphygmoCor XCEL, graded exercise test, and fitness test. Main results of this study are as follows: First, there are differences between smokers and non-smokers in cardiorespiratory and hemodynamic response functions, as shown by maximal oxygen consumption, exercise duration, and heart rate. Second, the although the arterial stiffness between smokers and non-smokers showed statistically significant differences in the speed of the pulse wave velocity and augmentation index, smoker had a faster rate. It shows that smoking behavior has a negative impact on the cardiovascular system. Third, pre-exercise smoking behavior does have an impact on cardiorespiratory and hemodynamic response functions, as shown by exercise duration and heart rate. Lastly, arterial stiffness between smokers and non-smokers showed statistically not significant in the speed of the pulse wave velocity and augmentation index. However, the difference was not statistically significant. Brachial systolic pressure, a component of pulse wave analysis, on the other hand, was significantly dependent on pre-exercise smoking behavior. Subjects who participated in this study are college students in early 20s. Given their relatively short history of smoking, it is possible that their smoking habits are not severe enough to develop into cardiorespiratory or cardiovascular diseases. But Smokers showed lower levels of cardiopulmonary functions, as maximal oxygen consumption and exercise duration than nonsmokers.

• (The) Research of the performance art and culture
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• no.19
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• pp.221-280
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• 2009

This thesis is a study of the rise and the characteristic of 'Hyangto Gakeuk(literally Song drama of the country or local music drama)' in the Early 1940s. During the colonial period, there were attempts to incorporate traditional Korean music elements with Western operatic form. This type of music drama with librettos based on traditional tales came to be known as 'Hyangto Gakeuk'. Mostly 'Hyangto Gakeuk' has led this effort under the director Seo Hang-Suk, the composer Ahn Ki-Young and the lyricist Seol Eui-sik. In the first chapter, the study aims at arranging the performance history of 'Hyangto Gakeuk' composed by Ahn Ki-Young. Also, the study examined representative works after classifying 'Hyangto Gakeuk' performed by Lamila Music Drama Troupe, and Bando Music Drama Troupe. There is significant meaning to evaluate 'Hyangto Gakeuk' in the history of Korean music drama through this analysis of the performance history. In the second chapter, I will analyze with representative works composed by Ahn Ki-Young, a pioneer in the Korean art song. He tried to create the music that held the nationalism and tradition. His works which were called 'Kageuk' laid down the foundation of Korean original operatic style. This study demonstrated characteristics of 'Hyangto Gakeuk' as 'the beginning' in modern musical drama history and its effects on Korean musical drama developments. Namely, 'Hyangto Gakeuk' based on Korean traditions can be seen as examples of original modern musical in Korea. Practically, study on all the aspects of performance not only text generally studied, dramaturgy and criticism, but also performance concept and intention of creators in early period.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.436-445
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• 2023

Methane (CH₄) emissions from rice paddies are mainly observed using the closed chamber method or the eddy covariance method. In this study, a new observation technique combining a portable gas analyzer (Model LI-7810, LI-COR, Inc., USA) and an automatic opening/closing chamber (Model Smart Chamber, LI-COR, Inc., USA) was introduced based on the strengths and weaknesses of the existing measurement methods. A cylindrical collar was manufactured according to the maximum growth height of rice and used as an auxiliary measurement tool. All types of measured data can be monitored in real time, and CH₄ flux is also calculated simultaneously during the measurement. After the measurement is completed, all the related data can be checked using the software called 'SoilFluxPro'. The biggest advantage of the new observation technique is that time-series changes in greenhouse gas concentrations can be immediately confirmed in the field. It can also be applied to small areas with various treatment conditions, and it is simpler to use and requires less effort for installation and maintenance than the eddy covariance system. However, there are also disadvantages in that the observation system is still expensive, requires specialized knowledge to operate, and requires a lot of manpower to install multiple collars in various observation areas and travel around them to take measurements. It is expected that the new observation technique can make a significant contribution to understanding the CH₄ emission pathways from rice paddies and quantifying the emissions from those pathways.

• Korean Journal of Culture and Social Issue
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• v.15 no.3
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• pp.399-429
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• 2009

The purpose of this research examines the factors that influence happiness among Korean adolescents by focusing on psychological resource (as measured by self-efficacy), relational resource (as measured by social support) and financial resource (as measured by family's monthly income). In addition, the influence of academic achievement on happiness is examined. To examine the influence of socio-economic status and family's monthly income, adolescents living in three different districts in Seoul (from working to middle to upper class districts) were randomly selected and interviewed in their home. A total of 190 elementary school, middle school, high school and university students (male=83, female=107) completed the resiliency of efficacy scale developed by Bandura (1995) and emotional support and happiness scale developed by the present researchers, in addition to background information. The results of the path analysis are as follows. First, the most important predictor of happiness among Korean adolescents is relational resources. In other words, emotional support received from significant others was most predictive of happiness; more than 60 times the effect of family's monthly income, three times the effect of academic achievement, and two times the effect of resiliency of efficacy. The second most important factor that predicted the happiness of Korean adolescents was psychological resource (i.e., resiliency of efficacy), which had 30 times the effect of family's monthly income. In addition resiliency of efficacy played a mediating role between emotional support on one hand and happiness on the other. Third, those respondents who had higher academic achievement reported higher levels of happiness, which had 20 times the effect of family's monthly income. Fourth, family monthly income did not predict happiness among Korean adolescents. Fifth, socio-economic status and school level did not have direct influence on happiness but had mediating influence through their influence on emotional support. In other words, those respondents with higher socio-economic status and elementary school students were more likely to receive social support from significant others, which in turn increased their happiness. These results indicate that the most important predictor of happiness among Korean adolescents is emotional support, followed by resiliency of effic acy and academic achievement, indicating that those adolescents from wealthy families are not necessarily happier.

• Korean Journal of Culture and Social Issue
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• v.12 no.5_spc
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• pp.99-116
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• 2006

This paper discuss adolescent's a quality of life related with risk behavior. The purpose of this study investigate to influence on risk behavior(runaway, smoking, sexual behavior) of the protective factors that moderate adolescent's problem behavior(delinquency). The assumption of this study that the protective factors counterbalance the negative influence of risk factors and finally, diminish a the problem behavior including a delinquent. A total of 1,020 students of a vocational high schook and a 216 adolescents of a special groups(the public institution that consisted with a delinquent young man) completed the questionnaires(risk behavior, 5 protective factors) of compiled by this researcher. The protective factors have selected based on the various prior studies analyzed with adolescent's risk behavior a family functioning, a father(a mother) each and child communication, a self efficacy, and a social support. Statistics appled for the data analysis are Chisqure analysis, two-way ANOVA, and Standard Discrimination analysis. The results of this study are as follows. First, the special group is higher than the general group in the rate of runaway, smoking, and sexual deviant behavior. Second, the protective factors are not action in the special group have experienced delinquency, but are only action in the general group consisted with the students of a vocational high schools. This means that the protective factors discriminating the participation of the risk behaviors, and blocking out the intervention of a problem behavior in the general adolescents. Although each protective factor influence to different according to each risk behavior, a role of a parent-child communication, a family functioning, and self-efficacy high orderly. Finally, discussed based on the previous studies that the protective factors moderate the negative influence of risk factors, offset the connection between a risk behavior and a. problem behavior, and improve and a resilience and the quality of life of the adolescents.

• Environmental and Resource Economics Review
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• v.32 no.4
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• pp.217-238
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• 2023

Currently, automobile tax in Korea is imposed by multiplying the vehicle's engine displacement by a certain tax rate. However, the need for revision is being raised as it is pointed out that the current system does not reflect the immediate task of reducing greenhouse gas emissions. Accordingly, this study focuses on the positive relationship between engine displacement and CO₂ emissions, and seeks to calculate an appropriate automobile tax rate considering average CO₂ emissions. To this end, first, we estimated the average annual CO₂ emissions (kg/vehicle) for each engine displacement using the average CO₂ emissions for each vehicle displacement as of 2020. Next, multiple scenarios were analyzed considering the standard tax rate at $75 per ton of CO₂ emissions proposed by the IMF (2019). In particular, we compared the case of imposing a uniform carbon tax of $75 and the case of imposing a progressive tax based on CO₂ emissions by displacement. According to the results, it was confirmed that the uniform tax rate proposed by the IMF is difficult to apply to Korea as it is due to the impact of a decrease in tax revenue, and a tax scheme needs to be designed appropriately considering maintenance of tax revenue according to the current automobile tax, greenhouse gas reduction effect, and automobile tax reform trends in developed countries. For example, in the case of the K3 (1,598cc) of Kia Motors, a representative compact car sold in Korea, if we compare the tax burdens for each tax scenario, the tax burden will be about 220,000 KRW under the current system, about 79,000 KRW under the uniform tax rate, about 83,000 KRW under the progressive tax rate, and about 240,000 KRW under the progressive tax rate similar to the UK tax system, respectively. In this way, this study identified the current statuses of automobile registration and tax in Korea, and automobile tax reform trends in major developed countries, and analyzed the impact of automobile tax reform considering engine displacement and CO₂ emissions, focusing on the tax burden of the people.

• Economic and Environmental Geology
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• v.56 no.6
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• pp.661-674
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• 2023

From the seafloor of Taean, Chungcheongnamdo Province, a ship of the Joseon Dynasty was discovered for the first time in the history of underwater excavations in Korea in 2014 and was named Mado Shipwreck No. 4. A total of 27 unused whetstones loaded as tribute were discovered on the hull of Mado No. 4, which revealed that Mado Shipwreck No. 4 was a Grain transport ship that sank while carrying tribute from Naju to Hanyang between 1417 and 1425 (King Taejong to King Sejong). All of the 27 whetstones are in the shape of narrow and long sticks. The average values of length, width, thickness, and weight are 161.5 mm, 36.1 mm, 22.7 mm, and 253.2 g, respectively. The result of X-ray diffraction analysis shows that the constituent minerals are quartz, alkali feldspar, and plagioclase, which is similar to that of the high-resolution digital stereomicroscope analysis. The average porosity of Mado-2672 and 2673 is 2.69% and 1.78%, respectively, and the average surface hardness is 807.2HLD and 834.5HLD, respectively. It is interpreted that if the porosity increases beyond a certain level, it affects the decrease in surface hardness. All of these are made of feldspathic sandstones with an average SiO₂ content of 74.51% and were confirmed to be suitable as grindstones. They are all medium whetstones when classified based on the SiO₂ content. These whetstones are small in size and weight and are convenient to carry, so they are presumed to be a type of non-stationary whetstone, and are estimated to have been mainly used in the fields such as weapon polishing and craft production during the Joseon Dynasty.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.4
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• pp.323-336
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• 2023

We investigated the nickel potential and genesis of ultramafic rocks in the Yugu area to secure nickel resources in South Korea. The Yugu ultramafic rocks, located in the southwest of the Gyeonggi Massif, are characterized by spinel peridotite and exhibit strong serpentinization along their boundaries. The serpentinization is observed as olivine transformed to antigorite and chrysotile, while pentlandite, the nickel sulfide mineral, altered into millerite and awaruite. Serpentine displays distinct foliation, aligning subparallel to the ultramafic rock boundaries and foliation of Yugu gneiss. This suggests that the uplift of ultramafic rocks resulted in hydrothermal infiltration likely sourced from the Yugu gneiss metamorphism. The Yugu ultramafic rocks are residues after 5~18% partial melting of abyssal peridotite. Enriched light rare earth elements and Eu imply secondary metasomatism. Geochemistry suggests a link between the formation of Yugu ultramafic rock and the Triassic collision of the North and South China continents. The nickel content is around 0.17~0.21%, mainly contained in olivine and serpentine. Hence, in addition to the mineral processing study on the sulfide minerals, focused studies on oxide minerals for enhanced nickel recovery within the Yugu ultramafic rock are strongly suggested.

• Korean Journal of Culture and Social Issue
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• v.15 no.1
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• pp.95-132
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• 2009

Can money buy happiness? If not, what are the factors that influence happiness? What makes people happy? What are the factors that influence happiness among Korean adults? How can we better explain factors that influence happiness? These are the research questions that led to the analyses of psychological, relational, financial resources that influence happiness. To examine differences in socio-economic status, adults and elderly from three different districts that vary wealth and income were interviewed in their own home. A total of 313 respondents (male=133, female=180) between the ages of 20 through 80 completed a questionnaire that contained background information, emotional support scale and happiness scale developed by the present researcher and resiliency of efficacy developed by Bandura(1995). The results are as follows. First, monthly income influence happiness to some extent, but when the variable was excluded from the path analysis, the goodness-of-fit did not change significantly. Although those who have more money can be happier, those without much money can also be happy. These results indicate that financial resource has limited influence on happiness. In addition, monthly income did influence self-efficacy of respondents indicating that those with more money were not necessarily more confident about themselves. Second, an important factor influencing happiness is the relational resource. Emotional support was the most powerful predictor of happiness, four to five times more important than monthly income. Third, self-efficacy influenced happiness. Those respondents with higher resiliency of efficacy had higher happiness scores and the influence was two times greater than monthly income. Moreover, self-efficacy played a mediating role between emotional support and happiness. Fourth, those respondents with higher occupational achievement reported higher happiness score and the influence was two times greater than monthly income. Fifth, success of children influenced happiness score and the influence was 1.5 times greater than monthly income. Sixth, education did not directly influence happiness, but had an indirect influence through self-efficacy and occupational achievement. Seventh, age was not related to self-efficacy and happiness.