• Nuclear Engineering and Technology
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• v.54 no.9
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• pp.3250-3259
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• 2022

A new approach to the use of rice straw as a difficult-to-recycle agricultural waste was proposed. Potassium aluminosilicate was obtained by spark plasma sintering as an effective material for subsequent immobilization of ¹³⁷Cs into a solid-state matrix. The sorption properties of potassium aluminosilicate to ¹³⁷Cs from aqueous solutions were studied. The effect of the synthesis temperature on the phase composition, microstructure, and rate of cesium leaching from samples obtained at 800-1000 ℃ and a pressure of 25 MPa was investigated. It was shown that the positive dynamics of compaction was characteristic of glass ceramics throughout the sintering. Glass ceramics RS-(K,Cs)AlSi₃O₈ obtained by the SPS method at 1000 ℃ for 5 min was characterized by a high density of ~2.62 g/cm³, Vickers hardness ~ 2.1 GPa, compressive strength ~231.3 MPa and the rate of cesium ions leaching of ~1.37 × 10^-7 g cm^-2·day^-1. The proposed approach makes it possible to safe dispose of rice straw and reduce emissions into the atmosphere of microdisperse amorphous silica, which is formed during its combustion and causes respiratory diseases, including cancer. In addition, the obtained is perspective to solve the problem of recycling long-lived ¹³⁷Cs radionuclides formed during the operation of nuclear power plants into solid-state matrices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.361-370
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• 2021

The purpose of this study was to identify the factors influencing college life stress and life satisfaction of nursing students. The subjects included nursing students from some select areas. The research was conducted in November and December 2020. The data of a total of 227 nursing students were analyzed using descriptive statistics, t-test, ANOVA, Pearson correlations, and stepwise multiple regression analysis. The findings show that college life stress, economic conditions, and interpersonal relationships had significant effects on life satisfaction of the nursing students with an explanatory power of 27.1%. The study examined life satisfaction based on general characteristics and found variations according to college life satisfaction (F=5.88, p=.003), grades (F=7.07, p=.001), interpersonal relationships (F=8.80, p=.000), and economic conditions (F=10.53, p=.000). There was a statistically significant negative correlation between their college life stress and life satisfaction (r=-.436, p<.001). To summarize, these findings raise a need to provide nursing students with a strategy to address economic issues by reducing their academic stress through an improved educational environment, help them keep positive interpersonal relationships through effective communication, and offer them active information such as counseling so that they can achieve life satisfaction.

• Science of Emotion and Sensibility
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• v.24 no.2
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• pp.25-38
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• 2021

The aim of this study is to protect workers and pedestrians from accidents at night or bad weather by attaching optical fiber to existing safety clothing that is made only with fluorescent fabrics and retroreflective materials. A safety vest was designed and manufactured by applying optical fiber, and energy-harvesting technology was developed. The safety vest was designed to emit light using the automatic flashing of optical fibers attached to the film, and an energy harvester was manufactured and attached to drive the light emission of the optical fiber more continuously. As a result, first, the vest wearer' body was recognized from a distance through the optical fiber and retroreflection, which helped prevent accidents. Thus, this concept helps in saving lives by preventing accidents during night-time work on the roadside or activities of rescue crew and sports activities, or by quickly finding the point of an accident with a signal that changes the optical fiber light emission. Second, to use the wasted energy, a piezoelectric-element power generation system was developed and the piezoelectric-harvesting device was mounted. Potentially, energy was efficiently produced by activating the effective charging amount of the battery part and charging it auxiliary. In the existing safety vest, detecting the person wearing the vest is almost impossible in the absence of ambient light. However, in this study, the wearer could be found within 100 m by the light emission from the safety vest even with no ambient light. Therefore, in this study, we will help in preventing and reducing accidents by developing smart safety clothing using optical fiber and energy harvester attached to save lives.

• Journal of Electrochemical Science and Technology
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• v.13 no.1
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• pp.148-158
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• 2022

The electrochemical CO₂ reduction (ECR) to produce value-added fuels and chemicals using clean energy sources (like solar and wind) is a promising technology to neutralize the carbon cycle and reproduce the fuels. Presently, the ECR has been the most attractive route to produce carbon-building blocks that have growing global production and high market demand. The electrochemical CO₂ reduction could be extensively implemented if it produces valuable products at those costs which are financially competitive with the present market prices. Herein, the electrochemical conversion of CO₂ obtained from flue gases of a power plant to produce diesel and formic acid using a consistent techno-economic approach is presented. The first scenario analyzed the production of diesel fuel which was formed through Fischer-Tropsch processing of CO (obtained through electroreduction of CO₂) and hydrogen, while in the second scenario, direct electrochemical CO₂ reduction to formic acid was considered. As per the base case assumptions extracted from the previous outstanding research studies, both processes weren't competitive with the existing fuel prices, indicating that high electrochemical (EC) cell capital cost was the main limiting component. The diesel fuel production was predicted as the best route for the cost-effective production of fuels under conceivable optimistic case assumptions, and the formic acid was found to be costly in terms of stored energy contents and has a facile production mechanism at those costs which are financially competitive with its bulk market price. In both processes, the liquid product cost was greatly affected by the parameters affecting the EC cell capital expenses, such as cost concerning the electrode area, faradaic efficiency, and current density.

• Journal of the Korea Society of Computer and Information
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• v.27 no.2
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• pp.153-161
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• 2022

Physical activities are decreasing and sitting time is increasing due to the automation, smartization, and intelligence of necessary household items throughout daily life. Recent healthcare studies have reported that the likelihood of obesity, diabetes, cardiovascular disease, and early death increases in proportion to sitting time. In this paper, we develop a sitting posture correction cushion in real time using capacitive pressure sensor based on conductive textile. It develops a pressure sensor using conductive textile, a key component of the posture correction cushion, and develops a low power-based pressure measurement circuit. It provides a function to transmit sensor values measured in real time to smartphones using BLE short-range wireless communication on the posture correction cushion, and develops a mobile application to check the condition of the sitting posture through these sensor values. In the mobile app, you can visualize your sitting posture and check it in real time, and if you keep it in the wrong posture for a certain period of time, you can notify it through an alarm. In addition, it is possible to visualize the sitting time and posture accuracy in a graph. Through the correction cushion in this paper, we experiment with how effective it is to correct the user's posture by recognizing the user's sitting posture, and present differentiation and excellence compared to other product.

• Clean Technology
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• v.28 no.4
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• pp.316-322
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• 2022

The flow pattern at the inlet of the catalyst layer in a selective catalytic reduction (SCR) system is one of the key parameters influencing the performance of the denitrification process. In the curved diffusing parts between the ammonia injection grids and the catalyst layers, guide vanes are installed to improve flow uniformity. In the present study, a numerical simulation has been performed to investigate the effect of the geometrical configuration of the guide vanes on the aerodynamic characteristics of a denitrification facility. This application has been made to the existing SCR process in a large-scaled coal-fired power plant. The flow domain to be solved covers the whole region of the flow passages from the exit of the ammonia injection gun to the exit of the catalyst layers. ANSYS-Fluent was used to calculate the three-dimensional steady viscous flow fields with the proper turbulence model fitted to the flow characteristics. The root mean square of velocity and the pressure drop inside the flow passages were chosen as the key performance parameters. Four types of guides vanes were proposed to improve the flow quality compared to the current configuration. The numerical results showed that the type 4 configuration was the most effective at improving the aerodynamic performance in terms of flow uniformity and pressure loss.

• Journal of Mushroom
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• v.19 no.4
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• pp.322-328
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• 2021

This study was carried out to evaluate potential of Hypsizygus marmoreus (brown cultivar) as a functional food and drug materials. H. marmoreus were divided into pileus and stipe and extracted in hot water and 80% ethanol. The total polyphenol content was highest in the hot water extracts (pileus 17.15±0.19 mg of GAE g, stipe 7.37±0.16 mg of GAE/g) and pileus compared to the ethanol extracts (pileus 10.23±0.14 mg of GAE/g, stipe 3.76.±0.19 mg of GAE/g) and stipe. Also, hot water extracts of pileus from H. marmoreus (brown cultivar) was more effective DPPH, ABTS, ORAC value, reducing power than ethanol extracts and stipe extracts. The pileus and stipe extracts were confirmed to be non-cytotoxic in the mouse macrophage cell line RAW 264.7 determined by WST-1 (4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulphonate) assay. Overall, extracts of H. marmoreus (brown cultivar) was higher antioxidant activity than other mushrooms, and no cytotoxicity. Therefore, H. marmoreus (brown cultivar) showed potential as a functional food and drug materials. The brown cultivar of H. marmoreus have higher antioxidant activity than white cultivar, H. marmoreus seem to have different antioxidant activity depending on the cultivar.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.107-119
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• 2022

This study was a descriptive research study to identify the effects of related knowledge to COVID-19, infection control performance, and job stress in emergency department nurses due to COVID-19 on nursing performance, to improve emergency department nurses' ability to cope with emerging infectious diseases and to prepare basic data for effective nursing work. This study was collected data from August, 10 until September, 10, 2021, for 165 emergency department nurses in 26 hospitals, which were located in G province and designated as regional emergency medical institutions, and total 150 copies were finally analyzed. Data were analyzed using descriptive statistics, t-test, ANOVA, correlation, and multiple regression. As a result of analyzing the variables affecting the subject's nursing job performance by multiple regression using the hierarchical selection method, the higher the infection control performance and the higher the job stress, the more higher the nursing job performance, and the explanatory power was 18.4%. The study results showed that infection control performance, job stress, and non-shift work had an effect on nursing performance. It was thought that various plans to protect them, reduced tasks to efficiently perform and the nursing ability to cope with emerging infectious disease should be prepared to improve and reduce the job stress of emergency department nurses.

• Journal of International Area Studies (JIAS)
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• v.14 no.3
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• pp.421-440
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• 2010

This paper examines middle powers' ODA policy in the post cold war era and discusses its implication for Korean aid strategy. Middle powers' ODA has been more successful than that of super powers in promoting donors' positive images and in stimulating recipient countries' development. Middle powers tend to pursue multilateral solutions to international problems often by taking a mediator role, and their ODA policies set them apart from the great players in international politics. Middle powers' ODA is primarily aimed at reducing poverty and protecting human rights in least developed countries where humanitarian aid needs the most rather than promoting donors' interests. Also, middle powers have provided bilateral untied aid in the sectors of food aid and emergency relief and steadily devoted about 0.7% of their gross national income to ODA. Meanwhile, Korea as an emerging middle power and a new donor has been implementing its own aid strategy under the name of the Korean development model since the post cold war period. The Korean ODA was not successful in building donors' positive images by simply following the short term strategies of US and Japan. Yet, its ODA policy has been quite effective in sustaining local development by creating specific niches in which the country can specialize in. In specific, Korea has focused on developing the sectors of information and communication technology and industry energy in recipients' countries by maximizing its comparative advantage.

• Journal of Digital Convergence
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• v.20 no.1
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• pp.459-469
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• 2022

This study aims to provide basic data for the development of teaching methods to improve the performance confidence of performing core basic nursing skills in nursing students while availing of online education owing to COVID-19. Data were collected from 146 students in the Department of Nursing at N University located in C city. The collected data was analyzed using descriptive statistics, difference, correlation analysis, and multiple regression by using SPSS 23.0 program.. The subjects' performance confidence of core basic nursing skills was dependent on self-directed learning readiness (r=.368, p<.001), intrinsic goal motivation (r=.232, p=.005), extrinsic goal motivation (r=.344, p<.001), task value (r=.237, p=<.001), control of learning beliefs (r=.262, p=<.001), and self-efficacy for learning and performance (r=.443), p<.001) with a significant positive correlation. The results indicate that the factors influencing the subjects' performance confidence of core basic nursing skills were the 4th grade (β=0.413, p<.001), extrinsic goal motivation (β=0.307, p<.001), and self-efficacy for learning and performance (β=0.316, p=.005), and the explanatory power was 35.8% (F=8.354, p<.001). The research results showed that it is necessary to develop and apply various online-centered teaching and learning methods to increase the extrinsic goal motivation and self-efficacy for learning and performance of nursing students to enhance their performance confidence of core basic nursing skills. This will serve as a basis for preparing effective online centered nursing education strategies to improve performance confidence of core basic nursing skills.