• Journal of Nutrition and Health
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• v.55 no.6
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• pp.656-669
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• 2022

Purpose: This study investigates the relationship between sleep duration, sleep quality, time use, and dietary quality of adolescents. Methods: A cross-sectional study was conducted, enrolling 423 high school students (112 male and 311 female students) in Chungnam using a questionnaire comprising general characteristics, sleep status, use of time, and Nutrition Quotient for Korean Adolescents (NQ-A). Results: On weekdays, male students reported getting 6.6 hours of sleep, which was significantly higher than the 5.8 hours reported by female students. The sleep quality score between male and female students was not significantly different on weekdays and weekends. Comparing the students categorized as getting 6 hours of sleep duration on weekdays and 8 hours on weekends, a significantly higher total NQ-A score was obtained for the long sleep duration group of female students on weekdays. In male students who reported increased screen time on weekdays and study time on weekends, there was a greater frequency of short sleep duration. Our data also revealed that the longer the sleep duration higher the NQ-A score. In addition, higher NQ-A scores were determined with shorter screen time and more prolonged exercise time. Conclusion: Our results suggest that intense study time and excessive use of smartphones have a negative effect on sleep in high school students. In addition, poor sleep quality and lack of sleep are likely to affect eating habits and nutritional status. Therefore, there is a need to provide nutritional education to adolescents imparting knowledge that associates desirable sleep habits and the correct use of time.

• Korean Journal of Environment and Ecology
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• v.37 no.1
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• pp.1-12
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• 2023

We analyzed the distribution area of debris slopes in Mudeungsan (Mt. Mudeung) National Park by comparing aerial photos of the past (1966) and the present (2017) and identified the vegetation characteristics that affect the change in the area of the debris slopes by investigating the vegetation status of the debris slopes and the surrounding areas. The area of debris slopes in Mt. Mudeung appears to have been reduced to a quarter of what it used to be. Debris slopes here have decreased at an average rate of 2.3 ha/yr over 51 years by vegetation covers. Notably, most of the small-area debris slopes in the low-inclination slopes disappeared due to active vegetation coverage. However, there are still west-facing, south-west-facing, south-facing, and large-area debris slopes remaining because the sun's radiant heat rapidly raises the surface temperature of rock blocks and dries moisture, making tree growth unfavorable. Because of these locational characteristics, the small-scale vegetation in the middle of Deoksan Stony Slope, which is the broadest area, showed distinct characteristics from the adjacent forest areas. Sunny places and tree species with excellent drying resistance were observed frequently in Deoksan Stony Slope. However, tree species with high hygropreference that grow well in valleys with good soil conditions also prevailed. In some of these places, the soil layer has been well developed due to the accumulation of fine materials and organic matter between the crevices of the rock blocks, which is likely to have provided favorable conditions for such tree species to settle and grow. At the top of Mt. Mudeung, on the other hand, the forest covered the debris slopes, where Mongolian oaks (Quercus mongolica) and royal azaleas (Rhododendron schlippenbachii), which typically grow in the highlands, prevailed. This area was considered favorable for the development of vegetation for the highlands because the density of rock blocks was lower than in Deoksan Stony Slope, and the soil was exposed. Moreover, ash trees (Fraxinus rhynchophylla) and Korean maple trees (Acer pseudosieboldianum) that commonly appear in the valley areas were dominant here. It is probably due to the increased moisture content in the soil, which resulted from creating a depressive landform with a concave shape that is easy to collect rainwater as rock blocks in some areas fell and piled up in the lower region. In conclusion, the area, density of the rock blocks, and distribution pattern of rock block slopes would have affected the vegetation development and species composition in the debris slope landform.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.167-183
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• 2023

Gases originated from the final SNF (spent nuclear fuel) disposal site are very mobile in the barrier and they may also affect the migration of radioactive nuclides generated from the SNF. Mechanisms of gas-nuclide migration in the multi-barrier and their influences on the safety of the disposal site should be understood before the construction of the final SNF disposal site. However, researches related to gas-nuclide coupled movement in the multi-barrier medium have been very little both at home and abroad. In this study, properties of gas generation and migration in the SNF disposal environment were reviewed through previous researches and their main mechanisms were summarized on the hydrogeological evolution stage of the SNF disposal site. Gas generation in the SNF disposal site was categorized into five origins such as the continuous nuclear fission of the SNS, the Cu-canister corrosion, the oxidation-reduction reaction, the microbial activity, and the inflow from the natural barriers. Migration scenarios of gas in porous medium of the multi-barrier in the SNF repository site were investigated through reviews for previous studies and several gas migration types including ① the free gas phase flow including visco-capillary two-phase flow, ② the advection and diffusion of dissolved gas in pore water, ③ dilatant two-phase flow, and ④ tensile fracture flow, were presented. Reviewed results in this study can support information to design the further research for the gas-nuclide migration in the repository site and to evaluate the safety of the Korean SNF disposal site in view points of gas migration in the multi-barrier.

• Korean Journal of Culture and Social Issue
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• v.22 no.4
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• pp.595-622
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• 2016

This study aims to understand the process of family reunion of the ex-offenders. To this end, Korea Rehabilitation Agency under Ministry of Justice and Healthy Family Support Center conducted intensive interviews with ex-offenders, their families and with 8 counselors who are in charge of ex-offenders and their families' residential, psychological, and educational support. The data collected through the interviews were analyzed by Consensus Qualitative Research(COR). The followings are the results: the counselors found out that most of ex-offenders had experienced unhappy childhood which was lack of healthy relationship with their parents. Secondly, counselors noticed a common feature among the families of ex-offenders. The common feature was that they keep the fact that one of their parents was imprisoned to their children as a secret. Thirdly, through the data analysis, counselors could understand various factors that affect reunion of ex-offenders' families: the factors that helped successful reunion were ex-offenders' sense of responsibility, open and healthy communication among family members, and mutual understanding of being a good family member, whereas, irresponsible dependance to other family members, denier and avoidance from the family members against ex-offenders, and lost sense of being a family member were the factors that discouraged the reunion. It turned out that the kinds of crime that ex-offenders committed also affected family reunion. The processes of reunion were easier for those who served their time with fraud, embezzlement, whereas, it was much more challenging for those who served their time with rape, violence, or murder. Fourthly, counselors learned that "relaxation" is the key factor in the process of reunion of ex-offenders' families. They also emphasized that there should be thorough monitoring process before the intervention in the reunion process. This study contributes in terms of finding healthy ways of intervention with ex-offenders' families and developing programs that help ex-offenders to recover their relationship with their family.

• Journal of Technology Innovation
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• v.31 no.2
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• pp.303-332
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• 2023

This study comprises critical questions of "What kinds of intangible resources are significant to create and reinforce competitive advantages for the small and medium-sized enterprises(SMEs) that significantly influence the national economy? What kinds of capacities do SMEs need in consideration with the large changes in market environment and during crisis? With large changes to market environment, would different capacities affect performance of platform and general SMEs?" To examine these questions, I have provided Entrepreneurial Orientation, Absorptive Capacity, and Organizational Resilience as key capacities that influence the competitive advantage and performance of SMEs. In particular, I have substantiated the control effect of Organizational Resilience (a rising key capacity for enterprises in recent times) on Corporate Performance. Moreover, I have analyzed the control effect of Organizational Resilience on Corporate Performance by comparing platform and general companies, and also substantiated how control effects may vary depending on sub-factors of Organizational Resilience. The results of this study indicate that Entrepreneurial Orientation and Absorptive Capacity significantly and positively influence Corporate Performance. Organizational Resilience also demonstrate a positive influence on Corporate Performance. Notably, sub-factors of Organizational Resilience (risk preparation capacity, risk response capacity, and change initiative capacity) significantly control correlation between Entrepreneurial Orientation and Corporate Performance. Risk preparation capacity and change initiative capacity significantly control correlation between Absorptive Capacity and Corporate Performance. Additionally, the control effect of risk preparation capacity significantly control correlation between Entrepreneurial Orientation and Corporate Performance. Also, the control effect of risk response capacity correlations between Entrepreneurial Orientation and Corporate Performance demonstrated themselves significantly only in platform enterprises. The study's results indicate that Organizational Resilience not only directly influence Corporate Performance, but also strengthens Corporate Performance via mutual interaction with Entrepreneurial Orientation and Absorptive Capacity, although the control effect of Organizational Resilience may vary between platform enterprises and general enterprises. I expect such results to provide practical value to the management of small and medium-sized enterprises (SMEs).

• Journal of the Korean Society of Marine Environment & Safety
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• v.29 no.5
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• pp.417-426
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• 2023

Rapid climate change has resulted in glacial retreat and increased meltwater inputs in the Antarctic Peninsula, including King George Island where Marian Cove is located. Consequently, these phenomena are expected to induce changes in the water column light properties, which in turn will affect phytoplankton communities. To comprehend the effects of glacial retreat on the marine ecosystem in Marian Cove, we investigated on phytoplankton biomass (chlorophyll-a, chl-a) and various environment parameters in this area in December 2021 and January 2022. The average temperature at the euphotic depth in January 2022 (1.41 ± 0.13 ℃) was higher than that in December 2021 (0.87 ± 0.17 ℃). Contrastingly, the average salinity was lower in January 2022 (33.9 ± 0.10 psu) than in December 2021 (34.1 ± 0.12 psu). Major nutrients, including dissolved inorganic nitrogen, phosphate, and silicate, were sufficiently high, and thus, did not act as limiting factors for phytoplankton biomass. In December 2021 and January 2022, the mean chl-a concentrations were 1.03 ± 0.64 and 0.66 ± 0.15㎍ L^-1, respectively. The mean concentration of suspended particulate matter (SPM) was 24.9 ± 3.54 mgL^-1 during the study period, with elevated values observed in the vicinity of the inner glacier. However, relative lower chl-a concentrations were observed near the inner glacier, possibly due to high SPM load from the glacier, resulting in reduced light attenuation by SPM shading. Furthermore, the proportion of nanophytoplankton exceeded 70% in the inner cove, contributing to elevated mean fractions of nanophytoplankton in the glacier retreat marine ecosystem. Overall, our study indicated that freshwater and SPM inputs from glacial meltwater may possibly act as main factors controlling the dynamics of phytoplankton communities in glacier retreat areas. The findings may also serve as fundamental data for better understanding the carbon cycle in Marian Cove.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.217-228
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• 2019

This study was designed to investigate the effect of exercise prescription service on user satisfaction and reuse intention of fitness center users in C region, Gangwon-do. The subjects of this study were 250 fitness center users aged 20 and over. Survey was conducted to examine users satisfaction and reuse intention. The final analysis data is 227 copies and the results are as follows. First, there was a significant difference in sex at the facility of satisfaction of use(t=2.308, p=.022). The marriage showed a significant difference in the price among user satisfaction(t=2.490, p=.014) and reuse intention(t=-1.968, p=.05). Age showed significant differences in the duration of participation(F=7.117, p=.000), frequency (F=6.171, p=.000), and intensity(F=2.791, p=.027). User satisfaction showed significant differences according to price(F=6.171, p=.000), leader(F=3.083, p=.017) and reuse intention(F=2.699, p=.032). There was a significant difference in education groups in terms of duration of participation(F=3.656, p=.007) and frequency(F=3.164, p=.015). leader(F=5.170, p=.001) and price(F=2.899, p=.023) were different in user satisfaction. Jobs showed a significant difference in the duration of participation(F=4.685, p=.000), intensity(F=2.373, p=.023) and reuse intention(F=4.840, p=.000). Monthly income showed a significant difference in user satisfaction(F=4.651, p=.001) and facility(F=2.606, p=.037). Second, there was a significant difference in the duration of participation according to presence or absence of exercise prescription service(t=-4.410, p=.000). There was also significant differences in the user satisfaction(t=-7.951, p=.000), leader(t=5.304, p=.000), facility(t=2.033, p=.043) and reuse intention(t=4.640, p=.000) in terms of the presence of exercise prescription service. Third, in the relation between exercise prescription service and the participation level, there was a significant effect of the leader(β=.221, p=.001) and the price(β=.135, p=.045) of user satisfaction, and the reuse intention(β=.182, p=.007). Fourth, among the user satisfaction influenced by exercise prescription service, facilities(β=.178, p=.005) and leader(β=.497, p=.000) were found to affect reuse intention.

• Economic Analysis
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• v.26 no.1
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• pp.84-132
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• 2020

A central bank infers market expectations of future yields based on yield curves. The central bank needs to precisely understand the changes in market expectations of future yields in order to have a more effective monetary policy. This need explains why a range of models have attempted to produce yield curves and market expectations that are as accurate as possible. Alongside the development of bond markets, the interconnectedness between them and macroeconomic factors has deepened, and this has rendered understanding of what macroeconomic variables affect yield curves even more important. However, the existence of various theories about determinants of yields inevitably means that previous studies have applied different macroeconomics variables when estimating yield curves. This indicates model uncertainties and naturally poses a question: Which model better estimates yield curves? Put differently, which variables should be applied to better estimate yield curves? This study employs the Dynamic Nelson-Siegel Model and takes the Bayesian approach to variable selection in order to ensure precision in estimating yield curves and market expectations of future yields. Bayesian variable selection may be an effective estimation method because it is expected to alleviate problems arising from a priori selection of the key variables comprising a model, and because it is a comprehensive approach that efficiently reflects model uncertainties in estimations. A comparison of Bayesian variable selection with the models of previous studies finds that the question of which macroeconomic variables are applied to a model has considerable impact on market expectations of future yields. This shows that model uncertainties exert great influence on the resultant estimates, and that it is reasonable to reflect model uncertainties in the estimation. Those implications are underscored by the superior forecasting performance of Bayesian variable selection models over those models used in previous studies. Therefore, the use of a Bayesian variable selection model is advisable in estimating yield curves and market expectations of yield curves with greater exactitude in consideration of the impact of model uncertainties on the estimation.

• Journal of Animal Science and Technology
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• v.65 no.2
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• pp.336-350
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• 2023

Two experiments were conducted in this research. Experiment 1 investigated the spatial expression characteristics of calcium (Ca) and phosphorus (P) transporters in the duodenum, jejunum, and ileum of 21-day-old broilers provided with adequate nutrient feed. Experiment 2 evaluated the effects of dietary vitamin D₃ (VD₃) concentration (0, 125, 250, 500, 1,000, and 2,000 IU/kg) on growth performance, bone development, and gene expression levels of intestinal Ca and P transporters in 1-21-day-old broilers provided with the negative control diet without supplemental VD₃. Results in experiment 1 showed that the mRNA levels of calcium-binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), plasma membrane calcium ATPase 1b (PMCA1b), and IIb sodium-phosphate cotransporter (NaPi-IIb) were the highest in the broiler duodenum. By contrast, the mRNA levels of inorganic phosphate transporter 1 (PiT-1) and 2 (PiT-2) were the highest in the ileum. Results in experiment 2 showed that adding 125 IU/kg VD₃ increased body weight gain (BWG), feed intake (FI), bone weight, and percentage and weight of Ca and P in the tibia and femur of 1-21-day-old broilers compared with the negative control diet (p < 0.05). The rise in dietary VD₃ levels from 125 to 1,000 IU/kg further increased the BWG, FI, and weights of the bone, ash, Ca, and P (p < 0.05). No difference in growth rate and leg bone quality was noted in the broilers provided with 1,000 and 2,000 IU/kg VD₃ (p > 0.05). Supplementation with 125-2,000 IU/kg VD₃ increased the mRNA abundances of intestinal Ca and P transporters to varying degrees. The mRNA level of CaBP-D28k increased by 536, 1,161, and 28 folds in the duodenum, jejunum, and ileum, respectively, after adding 1,000 IU/kg VD₃. The mRNA levels of other Ca and P transporters (PMCA1b, NCX1, NaPi-IIb, PiT-1, and PiT-2) increased by 0.57-1.74 folds by adding 1,000-2,000 IU/kg VD₃. These data suggest that intestinal Ca and P transporters are mainly expressed in the duodenum of broilers. Moreover, the addition of VD₃ stimulates the two mineral transporter transcription in broiler intestines.

• Journal of the Korean Institute of Landscape Architecture
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• v.51 no.1
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• pp.56-71
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• 2023

Citizens' needs for urban green spaces are on the rise due to improved quality of life and increased interest in environments. The garden is noteworthy because it is small in size, making it less controversial to create in the city, and it is adjacent to the residential area, improving citizens' daily environment. Moreover, recently gardens is attracting attention as a tool for urban regeneration, such as being created in declining areas as part of a government project. Therefore, it is time to study the role and value of urban gardens in deteriorated areas in terms of space welfare. However, there are few studies that quantitatively evaluate the effects of gardens, and many prior studies are limited to focusing the green space larger than a certain size (e.g., parks and forests). Therefore, the aim of this study is to examine the effect of garden and gardening quantitatively, paying attention to social aspects such as life satisfaction and community of inhabitants. The study was conducted in an old row housing complex in Gojan1-dong, Ansan-si, Gyeonggi-do. In there, some of the dwellers voluntarily created outdoor gardens and engaged in gardening for a long time. In addition, after the 2017 Gyeonggi-do Garden Fair, several gardens have been maintained and used by residents there. For the first step, the field trip was done to research the status of the garden in the area, and then, a survey was conducted on whether or not gardening has an impact on the life satisfaction and community of residents. The results were analyzed by t-test and ANOVA. As a result, residents who are engaged in gardening are more active in the "neighborhood exchange" and "resident participation" than those who are not engaged in gardening. In addition, if residents voluntarily create a garden, the level of "satisfaction of life" is higher than those staying in the garden which is constructed by the government. And a resident who is gardening in the complex shows higher life satisfaction than those who garden outside of the complex. These results confirmed that the garden has positive effects promoting "exchanges with neighbors", "participation in the community", and "life satisfaction" of residents. It shows that it is important to ensure the right of residents to participate in the garden-making process as much as possible, and the garden's location should be paid attention to maximize the positive effect of gardens.