• Environmental and Resource Economics Review
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• v.31 no.2
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• pp.165-204
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• 2022

This study organized data from 2000 to 2014 for 20 grid-connected countries in Europe and analyzed the determinants of carbon emissions through the panel GLS method considering the problem of heteroscedasticity and autocorrelation. At the same time, the effect of introducing ETS was considered by dividing the sample period as of 2005 when the European emission trading system was introduced. Carbon emissions from individual countries were used as dependent variables, and proportion of generation by each source, power self-sufficiency ratio of neighboring countries, power production from resource-holding countries, concentration of power sources, total energy consumption per capita in the industrial sector, tax of electricity, net electricity export per capita, and size of national territory per capita. According to the estimation results, the proportion of nuclear power and renewable energy generation, concentration of power sources, and size of the national territory area per capita had a negative (-) effect on carbon emissions both before and after 2005. On the other hand, the proportion of coal power generation, the power supply and demand rate of neighboring countries, the power production of resource-holding countries, and the total energy consumption per capita in the industrial sector were found to have a positive (+) effect on carbon emissions. In addition, the proportion of gas generation had a negative (-) effect on carbon emissions, and tax of electricity were found to have a positive (+) effect. However, all of these were only significant before 2005. It was found that net electricity export per capita had a negative (-) effect on carbon emissions only after 2005. The results of this study suggest macroscopic strategies to reduce carbon emissions to green growth, suggesting mid- to long-term power mix optimization measures considering the electricity trade market and their role.

• Journal of the Korean Geotechnical Society
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• v.38 no.7
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• pp.5-24
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• 2022

The current performance evaluation of slope anchors qualitatively determines the physical bonding between the anchor head and ground as well as cracks or breakage of the anchor head. However, such performance evaluation does not measure these primary factors quantitatively. Therefore, the time-dependent management of the anchors is almost impossible. This study is an evaluation of the 3D numerical model by SfM which combines UAS images with terrestrial LiDAR to collect numerical data on the damage factors. It also utilizes the data for the quantitative maintenance of the anchor system once it is installed on slopes. The UAS 3D model, which often shows relatively low precision in the z-coordinate for vertical objects such as slopes, is combined with terrestrial LiDAR scan data to improve the accuracy of the z-coordinate measurement. After validating the system, a field test is conducted with ten anchors installed on a slope with arbitrarily damaged heads. The damages (such as cracks, breakages, and rotational displacements) are detected and numerically evaluated through the orthogonal projection of the measurement system. The results show that the introduced system at the resolution of 8K can detect cracks less than 0.3 mm in any aperture with an error range of 0.05 mm. Also, the system can successfully detect the volume of the damaged part, showing that the maximum damage area of the anchor head was within 3% of the original design guideline. Originally, the ground adhesion to the anchor head, where the z-coordinate is highly relevant, was almost impossible to measure with the UAS 3D numerical model alone because of its blind spots. However, by applying the combined system, elevation differences between the anchor bottom and the irregular ground surface was identified so that the average value at 20 various locations was calculated for the ground adhesion. Additionally, rotation angle and displacement of the anchor head less than 1" were detected. From the observations, the validity of the 3D numerical model can obtain quantitative data on anchor damage. Such data collection can potentially create a database that could be used as a fundamental resource for quantitative anchor damage evaluation in the future.

• Fashion & Textile Research Journal
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• v.24 no.6
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• pp.667-685
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• 2022

This paper aims to investigate 4D printing materials for soft robots. 4D printing is a targeted evolution of the 3D printed structure in shape, property, and functionality. It is capable of self-assembly, multi-functionality, and self-repair. In addition, it is time-dependent, printer-independent, and predictable. The shape-shifting behaviors considered in 4D printing include folding, bending, twisting, linear or nonlinear expansion/contraction, surface curling, and generating surface topographical features. The shapes can shift from 1D to 1D, 1D to 2D, 2D to 2D, 1D to 3D, 2D to 3D, and 3D to 3D. In the 4D printing auxetic structure, the kinetiX is a cellular-based material design composed of rigid plates and elastic hinges. In pneumatic auxetics based on the kirigami structure, an inverse optimization method for designing and fabricating morphs three-dimensional shapes out of patterns laid out flat. When 4D printing material is molded into a deformable 3D structure, it can be applied to the exoskeleton material of soft robots such as upper and lower limbs, fingers, hands, toes, and feet. Research on 4D printing materials for soft robots is essential in developing smart clothing for healthcare in the textile and fashion industry.

• Molecules and Cells
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• v.45 no.12
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• pp.896-910
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• 2022

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and potentially fatal virus. So far, most comprehensive analyses encompassing clinical and transcriptional manifestation have concentrated on the lungs. Here, we confirmed evident signs of viral infection in the lungs and spleen of SARS-CoV-2-infected K18-hACE2 mice, which replicate the phenotype and infection symptoms in hospitalized humans. Seven days post viral detection in organs, infected mice showed decreased vital signs, leading to death. Bronchopneumonia due to infiltration of leukocytes in the lungs and reduction in the spleen lymphocyte region were observed. Transcriptome profiling implicated the meticulous regulation of distress and recovery from cytokine-mediated immunity by distinct immune cell types in a time-dependent manner. In lungs, the chemokine-driven response to viral invasion was highly elevated at 2 days post infection (dpi). In late infection, diseased lungs, post the innate immune process, showed recovery signs. The spleen established an even more immediate line of defense than the lungs, and the cytokine expression profile dropped at 7 dpi. At 5 dpi, spleen samples diverged into two distinct groups with different transcriptome profile and pathophysiology. Inhibition of consecutive host cell viral entry and massive immunoglobulin production and proteolysis inhibition seemed that one group endeavored to survive, while the other group struggled with developmental regeneration against consistent viral intrusion through the replication cycle. Our results may contribute to improved understanding of the longitudinal response to viral infection and development of potential therapeutics for hospitalized patients affected by SARS-CoV-2.

• Journal of Life Science
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• v.33 no.4
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• pp.315-324
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• 2023

The underlying action of policosanol in lowering cholesterol level has not yet been clearly elucidated. Several recent studies have suggested that sterol regulatory element-binding proteins (SREBP)-1c play a role in the regulation of cholesterol synthesis via the fatty acid synthesis pathway. To date, no study has evaluated the effects of policosanol on SREBP-1c-mediated fatty acid synthesis. Therefore, this study aimed to investigate whether the SREBP-1c-mediated fatty acid biosynthetic pathway is associated with the cholesterol-lowering effects of policosanol. Seven-week-old C57BL/6 male mice were randomly divided into 7 groups (n=7 per group) and treated for 8 weeks as follows: 1) normal diet (normal control), 2) high-fat diet (HFD), 3) HFD+ethanol (Pol-0), 4) HFD+policosanol 1 mg/kg (Pol-1), 5) HFD+policosanol 2 mg/kg (Pol-2), 6) HFD+policosanol 4 mg/kg (Pol-4), and 7) HFD+simvastatin 50 ㎍/kg (positive control). Policosanol and simvastatin were administered at the same time every day while maintaining the HFD. Body weight and food intake were measured weekly for 8 weeks. After 8 weeks, serum cholesterol levels were measured, histological analysis was carried out, and the expressions of SREBP-1c and fatty acid synthase (FAS) in the liver tissues were examined. Policosanol reduced body weight and the amount of food intake in a dose-dependent manner. Serum cholesterol levels were significantly lowered in the Pol-1 and Pol-4 groups. The expression of SREBP-1c and FAS was also significantly decreased in the Pol-4 group. These results suggest that the cholesterol-lowering effects of policosanol can occur due to the inhibition of the expression of SREBP-1c and FAS.

• Journal of agricultural medicine and community health
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• v.48 no.2
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• pp.103-117
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• 2023

Objectives: This study aims to reveal the relationship between social relations and physical activity in the young-old and old-old elderly. Methods: Data from 2020 National survey of Older Koreans were used, and a total of 10,097 subjects over the age of 65 were included in analysis. The dependent variable was physical activity, and the independent variables were social relations barrier and motivational factors. x²-test and binary logistic regression were performed for data analysis. Results: The physical activity rate in the elderly were 40.8% in the young-old and 29.2% in the old-old. The socio-demographic characteristics affecting physical activity were the young-old elderly were sex, residential area, employment status and household income, and the old-old elderly were sex, age, residential area, education level and household income. The social relations barrier factors affecting physical activity were the young-old elderly were number of close friends, family care, exercise information search and video viewing, and the old-old elderly were household type, number of close friends, participation in exercise education, exercise information search and video viewing. The social relations motivational factors affecting physical activity were the young-old elderly were call with children/relative/friend, participation in sports activity, access time from home to parks, and the old-old elderly were call with children/relative/friend, participation in sports activity, satisfaction with green spaces. Conclusions: It was found that social relations barrier and motivational factors of the elderly are important factors to consider when developing physical activity promotion strategy, and there are also difference between the age of the elderly.

• Korean Journal of Ecology and Environment
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• v.56 no.4
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• pp.320-329
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• 2023

Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg^-1 Cd, 96% at 1.87 mg kg^-1 Cd, and 93% at 6.09 mg kg^-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg^-1, 13.06 mg kg^-1, and 79.11 mg kg^-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg^-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.

• Journal of Venture Innovation
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• v.6 no.4
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• pp.23-40
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• 2023

This study examines the customer value factors affecting the intention to continue using the mobile app of department stores, which are traditional offline retailers, in the retail industry that is rapidly digitalizing and becoming mobile. This study clarifies multidimensional customer value in three dimensions; functional, convenience, and social. Functional value refers to the integrated channel, and consistent customer experience provided between channels in the omnichannel retail environment, while convenience value is the convenience of saving time and effort save while customers use a mobile app. Social value refers to the improvement of social approval or social self-concept occurring due to the use of products or services related to green marketing within the mobile app of the department store. The influence of each on the dependent variable, the mobile app's continuous use intention, was analyzed by using the three dimensions of customer value as independent variables. Data was collected from customers who have a history of using the mobile app of Shinsegae Department Store in Korea, and a confirmatory analysis was conducted using Smart PLS 4.0. The analysis results showed that all three dimensions of customer value; functional value, convenience value, and social value, had a positive (+) influence on customers' intention to continue using the mobile app, and the influence of functional value had the greatest impact. As functional value appears to be the most important influencing factor due to the omnichannel retail trend by advancement of technology, it suggests that it is important for department stores, and offline retailers, to provide integrated channels. This provides insights into the direction of customer-centered strategy formulation for activating department store mobile apps and suggests basic analytical data for customized services and marketing activities that department stores can effectively meet the changing expectations and demands of customers through new mobile channels rather than existing offline channels.

• Journal of Life Science
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• v.34 no.7
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• pp.500-508
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• 2024

Recently, there has been increasing interest in enhancing the indoor air quality, particularly in response to the growing utilization of public facilities. The focus of this study was on assessing the efficacy and safety of an air sterilizer equipped with electrolytic salt catalysts. To that end, we evaluated the antimicrobial activity of the vapor spraying from the air sterilizer and its cytotoxicity in condensed form on human cell lines (HaCaT, BEAS-2B, and THP-1). Against the test organisms, which comprised five bacterial strains (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium) and one fungal strain (Candida albicans), the air sterilizer exhibited relatively high antimicrobial activities ranging from 10.89 to 73.98% following 1 and 3 hr of vapor spraying, which were notably time-dependent. Importantly, cytotoxicity assessments on human cells indicated no significant harmful effect even at a 1.0% concentration. Comprehensive safety evaluations included morphological observations, gene expression (Bcl-2, Bax) tests, and FACS analysis of intracellular ROS levels. Consistent with previous cytotoxicity findings, these estimates demonstrated no significant changes, highlighting the air sterilizer's safety and antimicrobial activities. In a simulated 20-hr operation within an indoor environment, the air sterilizer not only showed an 89.4% removal of total bacteria but also a 100.0% removal of Escherichia sp. and fungi. This research outlines the potential of the developed electrolytic salt catalyst air sterilizer to effectively remove indoor microbial pollutants without compromising human safety, underscoring the solution that it offers for improving indoor air quality.

• Journal of Life Science
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• v.34 no.7
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• pp.485-492
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• 2024

Sea cucumbers contain more than 50% protein in their solid content, and they also possess various bioactive substances such as saponins and mucopolysaccharides. This study analyzed the activities of various enzymes derived from Bacillus and lactic acid bacteria and determined to degrade the components of sea cucumbers. Among the analyzed strains, B. subtilis K26 showed the highest activities in protease and xylanase and relatively high activity in cellulase. Accordingly, samples of sea cucumber and water were mixed in equal proportions, sterilized, and then fermented by inoculating them with B. subtilis K26. Following this, a higher amino acid content was observed between 1.5 and 7.5 hr, a lower residual solid content in this time, and a lesser fermentation odor. The saponin content in fermented sea cucumber powder extracted with butanol was measured to be 1.12 mg/g. The chondroitin sulfate content was evaluated to be 5.11 mg/g in raw sea cucumber. The total polyphenol content, flavonoid content, and antioxidant activities were 6.95 mg gallic acid equivalent/g, 3.69 mg quercetin equivalent/g, and 3.69 mg quercetin equivalent/g in raw sea cucumber, respectively. Moreover, the DNA damage protective effect of fermented sea cucumber extract was found to be concentration-dependent, with a very strong effect at very low concentrations. Overall, we suggest that sea cucumber fermented with B. subtilis K26 has a high potential as a food for inhibiting oxidation, enhancing immunity, and improving muscle function in the human body thanks to its high free amino acid content.