• Korean Journal of Materials Research
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• v.34 no.7
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• pp.370-376
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• 2024

In this study, we report significant improvements in lithium-ion battery anodes cost and performance, by fabricating nano porous silicon (Si) particles from Si wafer sludge using the metal-assisted chemical etching (MACE) process. To solve the problem of volume expansion of Si during alloying/de-alloying with lithium ions, a layer was formed through nitric acid treatment, and Ag particles were removed at the same time. This layer acts as a core-shell structure that suppresses Si volume expansion. Additionally, the specific surface area of Si increased by controlling the etching time, which corresponds to the volume expansion of Si, showing a synergistic effect with the core-shell. This development not only contributes to the development of high-capacity anode materials, but also highlights the possibility of reducing manufacturing costs by utilizing waste Si wafer sludge. In addition, this method enhances the capacity retention rate of lithium-ion batteries by up to 38 %, marking a significant step forward in performance improvements.

• Environmental and Resource Economics Review
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• v.21 no.2
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• pp.321-340
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• 2012

Korean government recently announced that new passenger cars sold within South Korea in 2009 ran an average of 12.27 kilometers per liter of fuel, which is an 7% point increase of the fuel efficiency. The government interpreted these improvements in the fuel economy as energy savings of 60,000 toe and as a reduction of 160,000 ton $CO_2$ emissions. However, improvements in energy efficiency make energy services cheaper, which is known as rebound effect. If this rebound effect exists, and the size of the effect is not negligible, ignoring this could result in overestimating the energy savings achieved by the fuel efficiency increase. Using detailed data on household and vehicle characteristics, our results suggest that there exist a short-run rebound effect of 0.299(29.9%) for the Korean automobile industry. This is notably smaller than the estimates of West (2004), which finds an estimate of 87% using cross-section data for the US. Furthermore our results highlight the importance of rebound effect on energy savings and the $CO_2$ emissions reduction. Our estimates suggest that the report from Korean government overestimates the energy savings and related $CO_2$ emissions by 29.9% point.

• Asian Journal for Public Opinion Research
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• v.8 no.1
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• pp.3-21
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• 2020

This study examined the relationship between residential environmental satisfaction and quality of life, and how the relationship between variables differed depending on housing type. Residential environments can affect a person's life in a variety of ways. However, there have not been many studies on the relationship between quality of life and residential environments, which increases the importance of this study. In this study, residential environments were categorized according to amenities, safety, and neighborhood relationships, which enabled the comparison of influence between these elements. In addition, this study analyzed the moderating effect of housing type to look for improvements for low-rise housing residents. For testing the hypotheses, moderating regression analysis was conducted with data from the 1^st Gyeonggi Province quality of life survey that had 18,953 subjects. Results showed that residential environmental satisfaction had a positive effect on quality of life, with amenities having the largest influence. Furthermore, housing type had a significant moderating effect on the relationship between safety and quality of life. In other words, safety was proven relatively important in improving quality of life for low-rise housing residents. Today, with the limits to quantitative growth, qualitative development has become more important. In this respect, this study provides important implications for many developing countries undergoing urbanization.

• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.351-367
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• 2018

This study aimed to analyze socioeconomic effect of eco-friendly free school food supply system by Seoul, which has been consistently extended since 2011. To do so, effect of eco-friendly free school food supply system on the beneficiaries, Seoul citizens, was analyzed by using 'labor & income panel', while that on rural society was analyzed by using the surveys on the eco-friendly agricultural product supply performance by the 'Eco-friendly Agricultural Products Retail Center' as well as for students, school parents, nutrition teachers and nutritionists. The results of analysis showed that eco-friendly school food supply system contributes to income redistribution among the Seoul citizens to a certain extent, provides the eco-friendly agricultural product producers in the rural society with the stable market, and positively influences them to secure stable incomes. In addition, eco-friendly free school food reduced the amount of carbon emissions through the use of environmentally friendly agricultural products resulting in environmental improvements and economic benefits. Considering such effects, free school food supply using the eco-friendly agricultural products needs to be consistently maintained in the future without politic change by political ideology and to be extended to middle school level in medium and short-term.

• Asia-Pacific Journal of Business
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• v.15 no.1
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• pp.335-352
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• 2024

Purpose - Low fertility rate is a serious problem, and this study analyzes factors affecting total fertility rate using panel data from 16 metropolitan cities and provinces in Korea from 2000 to 2022. Design/methodology/approach - Estimating the SAR model considering the weak cross-sectional dependence that exists in variables related to the regional total fertility rate, and using the DKSE estimation method considering the strong cross-sectional dependence. Findings - Estimation results considering weak and strong cross-sectional dependence were similar, confirming the robustness of the results. Female labor force participation rate has a positive effect on total fertility rate, and employment rate has no effect. However, the interaction term is a negative (-) sign. Crude marriage rate has a positive effect on total fertility rate, and apartment price has a slightly positive effect. Environmental factor has no effect, and policy factor has a negative effect. Research implications or Originality - In order for an increase in the female labor force participation rate to lead to an increase in the total fertility rate, qualitative improvements in female employment must be made. Financial investment policies for childbirth must increase their effectiveness. The problem of low fertility rate requires not only population policy but also social, economic, cultural, environmental, and policy conditions to be considered.

• Journal of the Korean housing association
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• v.23 no.5
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• pp.31-39
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• 2012

This study has analyzed the effect of the housing affordability improvement of the residents in the metropolitan areas, applying Transit Supportive Home Loan (TSHL) which extends the loan amount according to the transportation cost saving based on Location Efficiency Mortgage (LEM) System in the USA. The previous studies focused on introducing LEM system to Korea, whereas this study has analyzed TSHL effect for the first time, taking into account the situation in Korea. For analysis, The Transportation Savings (TS) is calculated and Housing Affordability Index (HAI) is drawn by applying increased TS and DTI (Debt to Income), so the improvements of housing purchasing ability is examined by HAI's improvement. As a result, transit commute 1 (having own car) and transit commute 2 (without having own cars) respectively produce the TS of monthly average 36 thousand won and 110 thousand won in comparison with car using commute. Each additional loan (TSHL) amounts to 16.57 million won and 54.07 million won. As the distance is farther and the house price cheaper, the improvement of HAI is more outstanding. City hall area showed the highest improvements of HAI by 9.3% (transit commute 1) and 21.9% (transit commute 2) increase, in comparison with car using commute.

• Journal of Life Science
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• v.17 no.10
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• pp.1419-1425
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• 2007

The purpose of the present investigation was to determine the effect of combine exercise on C-reactive protein(CRP) and adiponectin, and to asses whether combine exercise-induced changes in insulin resistance could be explained in part by changes in these in these inflammation markers. Twenty two participants (BMI >95 percentile for age and sex) were allocated exercise group(n=12) and control group(n=10). Subjects had their body shape, body composition, glucose. insulin, HOMA-IR, CPR and adiponectin levels measured. Modest improvements in body composition, insulin resistance markers were observed, however, adiponectin and CRP did not changes. These data suggest that adiponectin and CRP is not a contributory factor to the exercise-relateted improvements in insulin resistance. Additional studies are needed to assess the effects of different duration, modes and intensities of exercise on inflammation markers.

• Journal of The Korean Society of Integrative Medicine
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• v.2 no.1
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• pp.51-62
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• 2014

Purpose : The purpose of this work was to ascertain the effects of cervical traction on the pain, the range of motion and the quality of sleep of the older women with the tension headache. Method : 25 subjects between ages 66 and 82 who agreed on this experiment and diagnosed with tension headache participated in this study. All subjects were treated with air-pressure cervical traction while 20 minutes a day, 3 times per week, for 4 weeks. The effects of air-pressure cervical traction were evaluated by PSQI(Pittsburgh sleep quality index), a pain last a day, VAS, and four ROMs. In order to investigate the effect of age on the treatment, subjects were divided into two groups, of less and of over than age 75. The measured data were analyzed by using one-way repeated ANOVA and two-way repeated ANOVA. Result : 1) The group of less than age 75 showed the significant improvements in all measurement variables, PSQI, a pain last a day, VAS and four ROMs. 2) The group of over than age 75 showed the significant improvements in all measurement variables excluding the flexion ROM of cervical. 3) No significant differences between two groups were showed in all measurement variables, but the interaction effect between group and period was significant in only VAS. Conclusion : From the results of this study, a cervical traction intervention using an air-pressure cervical traction proved to be effective on the reduction of tension headache and the improvement of the quality of sleep.

• Journal of the Korean Society of Physical Medicine
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• v.16 no.4
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• pp.23-31
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• 2021

PURPOSE: This study compared the effect of training ankle joint and hip joint thera-band exercise on balance. METHODS: The participants were divided into two groups of 11 each. Group A performed hip exercise after ankle exercise, and Group B performed ankle exercise after hip exercise. Using a green thera-band, the dorsiflexion and plantarflexion and hip flexion and hip extension were exercised repeatedly for 15 seconds three times with a five-second rest between each set. After the exercise and measurement of one area were complete, the exercise and measurement of the other area were performed at one-day intervals. The balance ability was assessed using a Tetrax and Y-balance test and repeated three times; the best values were taken. RESULTS: In the stability index (ST) of the static balance, the hip joint exercise group (HTG) during the follow-up of normal eye open (NO) revealed notable improvement over the ankle joint exercise group (ATG), and in the follow-up of the normal eye closed (NC), the ATG showed significant improvement over the HTG. In the pillow with eye closed (PC) follow-up, the ATG showed significant improvements over the HTG. At the left (Lt) and Y-balance test (YBT), the ATG showed significant improvements in the follow-up over the HTG (p <.05). CONCLUSION: In static balance, the ATG showed significant improvement in the follow-up of NC and PC over the HTG. In the dynamic balance, the Lt. dynamic balance on the non-dominant side in the ATG showed significant improvement in the follow-up over the HTG.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.28 no.1
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• pp.9-17
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• 2022

Background: Functional massage is a therapeutic massage that incorporates joint motion in non-end-range to reduce pain and improve range of motion (ROM) in patients. This study was aimed at investigating the immediate effect of functional massage on pain, range of motion, balance ability and, gait speed of patients having undergone total hip replacement. Methods: Twenty patients were treated by one participating orthopedic manual physical therapist and randomly assigned to the control group (n=10) or the experimental group (n=10). To treat patients of each group, functional massage and range of motion exercises were used. The experimental group received a functional massage and the control group received range of motion exercise for minutes for one session. The visual analog scale was used for pain assessment. Balance ability was measured using a timed up and go test and a one-leg standing test for patients. The 10-meter walk test was used for the measurement of gait speed assessment of patients. Results: Significant improvements were observed in terms of balance ability (p<.05), gait speed (p<.05), and ROM (p<.05) after functional massage. There was no significant inter-group difference (p>.05). Conclusion: Application of the functional massage showed that statistically significant improvements in ROM, gait speed, and balance ability after a single treatment session. This technique may be a useful treatment in patients having undergone total hip replacement.