• Journal of Climate Change Research
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• v.5 no.4
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• pp.359-366
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• 2014

This research was conducted to estimate methane emission from paddy field of 16 local government levels using the DNDC(DeNitrification-DeComposition) model from 1990 to 2010. Four treatments used in DNDC model for methane emission calculations were (1) midseason drainage with rice straw, (2) midseason drainage without rice straw, (3) continuous flooding with rice straw, and (4) continuous flooding without rice straw. Methane emissions at continuous flooding with rice straw were the highest ($471kg\;C\;ha^{-1}$) while were the lowest ($187kg\;C\;ha^{-1}$) at midseason drainage without rice straw. The average methane emission for 21 years was the highest ($1,406Gg\;CO_{2-eq}$.) in Jeonnam province because of its large cultivation area. Jeju province had the highest the average methane emission per unit area due to the organic content in soil.

• Journal of Climate Change Research
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• v.5 no.4
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• pp.339-348
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• 2014

Agro-ecosystem plays an important role in the mitigation of atmospheric $CO_2$ concentration through photosynthesis and soil carbon fixation. The perennial crops have capacity of carbon accumulation because they have lived for years in the same position. Carbon dioxide fixation occurs in the fruit orchard by photosynthesis and soil carbon sequestration. The objectives of this review are to introduce the fruit orchard as a carbon dioxide sink and to summarize the methods that measure $CO_2$ flux in the orchard. There are three difference methods (chamber, biomass, and eddy covariance method) to measure $CO_2$ exchanges on sites. However, there is no standard method suitable for fruit cultivation condition in Korea. Thus the standard method have to be developed in order to exactly estimate the carbon accumulation. In foreign studies, the carbon assessments were conducted in apple, peach, olive, grape orchard and so on. On the other hand the estimation of $CO_2$ exchange was carried out for apple and mandarine orchard in Korea. According to these results, fruit orchard is a $CO_2$ sink even though amount of carbon accumulation is smaller than the forest. To introduce certainly fruit orchard as greenhouse gas sink, long-term monitoring and further study have to be conducted under each planting condition.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.7
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• pp.289-302
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• 2019

Structural change of time series means that the distribution of observations is relatively stable in the period of constituting the entire time series data, but shows a sudden change of the distribution characteristic at a specific time point. Within a non-stationary long-term time series, it is important to determine in a timely manner whether the change in short-term trends is transient or structurally changed. This is because it is necessary to always detect the change of the time series trend and to take appropriate measures to cope with the change. In this paper, we propose a method for decision makers to easily grasp the structural changes of time series by visualizing the test results based on the unit root test. Particularly, it is possible to grasp the short-term structural changes even in the long-term time series through the method of dividing the time series and testing it.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.507-514
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• 2018

This study utilized latent growth curve modeling to investigate the trajectories of adolescent life satisfaction changes in middle and high school students. The effects of self-esteem, career identity, school learning activity, gender, and household earnings on life satisfaction changes were examined. Data was obtained from the Korea Child Youth Panel Survey (KYCPS), a longitudinal study following students for 7 years. Year 3-6 data was utilized. Results found that the life satisfaction trajectory resulted as a quadratic model in which individual differences were significant. Second, school learning activity used as a time variant variable had a positive significant effect on life satisfaction each year. Third, gender and self-esteem as time invariant variables had significant effects on initial levels while self-esteem had effects on the slope and quadratic change. Further implications and research issues are discussed.

• Journal of Convergence for Information Technology
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• v.11 no.1
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• pp.34-44
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• 2021

This study aimed to understand the meaning and essence of the experience of bodily change in young-old adults. van Manen's hermeneutic phenomenological method was utilized. Study participants were 11 elderly who 65 to 74 residing in J city. Data were collected from in-depth individual interviews with the participants from July to September 2016. The essential themes were identified regarding the experience of bodily change in young-old adults: 'self-pity about perceived aging', 'myself projected onto others', 'wants to hold on passing of the time', and 'priority on wellbeing than appearance'. The present findings can be used as important basic data for the development of nursing interventions and improving quality of life for young-old adults.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.194-204
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• 2021

The purposes of the study were two-folded: to identify visitors' motivations for the history-based dark tourism and to test empirically the relationships among visitors' motivations, authenticity, emotion, satisfaction and attitude change. The online survey was conducted, from August 3rd to 20th of 2020, on visitors over 15 years old with previous experience with dark tourism within last three years. 347 individuals responded to the online survey. The study results were as follows: first, among four dark tourism visiting motivation including, motivation to research, historicalness, deviation, and self-examination, first two variables motivation to research and historicalness showed positive effect on authenticity and emotion. Second, the study found that visitors' satisfaction influenced positively towards attitude change. Finally, authenticity and emotion positively influenced attitude change. This study empirically suggests a change in attitude toward history due to the dark tour. Since historicality has been shown to have a significant influence on the attitude of history through authenticity and emotion, it is necessary to strengthen story-based experience programs at historical sites.

• Journal of The Korean Association of Information Education
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• v.26 no.1
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• pp.35-44
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• 2022

Previous studies showed that an improvement in attitude toward a subject affects academic achievement in the subject. The purpose of this study is to confirm that the AI education program causes changes in the AI attitude of gifted children in elementary school, and that the change in attitude leads to a change in literacy. In this study, we conducted an AI education program for gifted children, and analyze the effect of AI education program on the change in AI attitude AI literacy through pre- and post-test. The result of the analysis showed the statistically significant improvement of AI attitudes. In addition, through regression analysis it was found that the change in AI attitude has a statistically significant direct effect on the change in AI literacy. This study has a limitation in that self-evaluation was used to measure AI attitudes and literacy and conducted to a relatively small number of samples. Even though, it was also confirmed that the activities of making an AI programs experienced in real-life can cause changes in AI attitudes and literacy.

• The Journal of the Korea Contents Association
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• v.22 no.3
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• pp.606-616
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• 2022

This study explored the degree of change in children perceived by single parents and examined the effect of single parents' spending family time and participation of leisure activities on their school-aged children. Hierarchical multiple regression was utilized to analyze data of 1,162 people who responded to the single parent survey collected by the Korea Women's Policy Research Institute in 2018. Results showed that single parents' spending family time and participation of leisure activities influenced positive change on their school-aged children. Implications and suggestions to support single parents' parenting environment are discussed.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.554-568
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• 2021

Forests are the largest carbon (C) sinks in terrestrial ecosystems. Recently, as enhancing forest C sequestration capacity has been proposed as a basic direction of the Republic of Korea's "2050 Carbon Neutral Strategy," accurate estimation of forest C sequestration has been emphasized. According to the Intergovernmental Panel on Climate Change guidelines, sequestration quantity is calculated from changes in C stocks in forest C pools, such as biomass, deadwood, litter and soil layer, and harvested wood products. However, in Korea, only the overstory biomass increase is now considered the amount of sequestration quantity, so there can be a significant difference from the actual forest C sequestration. In this study, we quantified forest C exchange through C flux measurement using an eddy covariance system and an automated soil chamber system in a 57-year-old Korean pine plantation located in Mt. Taehwa, Gwangju-si, Gyeonggi-do. Then, the net amount of C sequestration was compared with the amount of the overstory biomass increase. We estimated the annual C stock change in the remaining C pools by comparing the net sequestration amount from the C flux measurement with the overstory biomass increase and C stock change in the litter layer. Therefore, the net C sequestration of the Korean pine plantation estimated from the flux measurement was 5.96 MgC ha^-1, which was about 2.2 times greater than 2.77 MgC ha^-1 of the overstory biomass increase. The annual C stock increase in the litter layer was estimated to be 0.75 MgC ha^-1, resulting in a total annual C stock increase of 2.45 MgC ha^-1 in the remaining C pools. Our results indicate that the domestic forest is a larger C sink than the current methods, implying that more accurate calculations of the C sequestration capacity are necessary to quantify C stock changes in C pools along with the C flux measurement.

• Korean Journal of Heritage: History & Science
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• v.55 no.1
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• pp.265-280
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• 2022

Hwangnyongsa Temple was the large Buddhist monastery of Silla that has existed for about 685 years. The temple underwent a series of excavations from 1976 to 1983, during which it was discovered that its layout consisted of one pagoda and three main dharma halls. This discovery also led to the production of four artistic depictions of the temple at various times from its foundation to its final phase. Previous studies on the architectural layout of Hwangnyongsa Temple are largely focused on the inner sanctuary ("Buddha's Land"). The studies on the temple's main architectural structures may be natural for those who are interested in the origins of and background to its establishment, but the studies on its outer sanctuary ("Sangha's Land") have to come first to acquire a deeper knowledge of the architectural layout of the temple as a whole. To gain a comprehensive understanding of the entire layout of Buddhist monasteries of the Silla dynasty, including both their inner and outer sanctuaries, the studies on Hwangnyongsa Temple are essential as it was once the kingdom's most highly honored temple. The studies on Korean Buddhist monasteries of the Three Kingdoms Period have produced only a limited amount of information concerning the outer sanctuary, resulting in little evidence about the exact scope of the temple's sanctuary. Meanwhile, the excavations of the Hwangnyongsa Temple site have revealed the archaeological features of the walls that divided the monastery and its neighboring facilities, thus helping to delineate the size of the temple site. The excavations have revealed the boundaries between the inner and outer sanctuaries of Hwangnyongsa Temple, as well as the entire temple precincts and the exterior, providing valuable information about the changes made to the layout of the temple. In this study, the main discussion focuses on the changes made to the sanctuary of Hwangnyongsa Temple during the Unified Silla and Goryeo Periods, particularly in relation to the architectural layout of the temple. The discussion is based on a review of the periods in which the Nammunji(South Gate site) was built, which provides tangible evidence about the expansion of the temple to the south, and the walls enclosing the temple precincts on the four sides and the changes that occurred afterwards. As a result, the study concludes that both the inner and outer sanctuaries of the temple probably changed through the 1 st and 3rd. It also concludes that the changes made to the architectural layout of Hwangnyongsa Temple were intended not only to alter the scope of the temple but were also closely associated with the politico-geographical significance of its location at the center of the royal capital of Silla and the urban archaeological remains around it.