• Applied Chemistry for Engineering
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• v.32 no.3
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• pp.320-325
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• 2021

In this study, an optimization for the production of water emulsion was designed by adding an extract of wheat sprout, which is known to contain a large amount of antioxidants. The central composite design of reaction surface analysis method (CCD-RSM) was used for the optimization process. The amount of emulsifier, emulsification time, and added amount of wheat sprout extract were selected as independent variables based on our preliminary experiments. The mean droplet size (MDS), viscosity, and emulsion stability index (ESI) were set as the responses to evaluate the stability of the emulsion. For each independent variable, the P-value and coefficient of determination were evaluated to verify the reliability of the experiments. From the result of CCD-RSM, optimum conditions for the emulsification were determined as 23.6 min, 7.7 wt.%, and 3.9 wt.% for the emulsification time, amount of emulsifier, and amount of sprout, respectively. From the optimized condition obtained, MDS, viscosity, and ESI after 7 days from reaction were estimated as 252.3 nm, 616.7 cP, and 88.7%, respectively. The overall satisfaction was 0.9137, which supported the validity of the experiments, and the error rate was measured at 0.5% or less by advancing the experiments. Therefore, an optimized process for producing an emulsion by adding the malt extract was designed by the CCD-RSM.

• Journal of the Korean Geotechnical Society
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• v.37 no.6
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• pp.29-37
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• 2021

Since many geotechnical structures are constructed on a weathered granite layer, it is important to evaluate their characteristics. As a seismic design is the more important nowadays, the demands to estimate a shear wave velocity (V_S) based on acceptable methods are increasing. In this study, an empirical equation predicting V_S of the weathered granite layer is suggested based on the nonlinear multiple variable regression analysis whose independent variables are both SPT (Standard penetration test)-N₆₀ and chemical weathering index. It is concluded that the accuracy of the empirical equation estimating V_S of the weathered granite layer increases when it considers the chemical weathering index as an additional independent variable compared to the result of simple regression analysis using only N₆₀.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.385-392
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• 2021

In general, earth retaining work in construction works enables the construction of structures, prevents the displacement of the surrounding ground to the maximum extent, and plays an important role in ensuring the safety of the surrounding structures and field workers. The earth retaining work and the construction method differ according to the various ground characteristics, surrounding topographical characteristics, repair environment, and design conditions. In particular, in the case of Seoul city, the environments and ground conditions differ according to the area. This study analyzed the earth retaining work cost mainly for the apartment construction project in Seoul and calculated the approximate earth retaining work cost at the project planning stage. A model was developed to predict the cost of earth retaining work that matches the characteristics of Seoul City and predict the construction cost for earth retaining work. This paper presents the predicted earth retaining work cost using a multiple regression model that applies 10 project outlines as independent variables. The error rate of the prediction result of the earth retaining work cost of the apartment construction project in Seoul using multiple regression models was 10.75%.

• Journal of Mushroom
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• v.18 no.4
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• pp.372-379
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• 2020

Snow fungus (Tremella fuciformis) with functional contents has satisfactory effects on various diseases, including atherosclerosis, high cholesterol, healthy skin, cancer, diabetes, and anti-inflammation. In this study, the extraction yield and functional contents (ergothioneine and 𝛽-glucan) of white jelly fungus were compared based on the extraction conditions using response surface methodology. Results revealed the extraction conditions for optimization of the dependent variables to be 60℃ and 4.33 h, when 16.6 mg/mL of sample concentration was used. Under these conditions, the extraction yield was 24.9%, including ergothioneine (66.8 ㎍/g) and 𝛽-glucan (34.9 g/100 g). These results can be useful in understanding the functional ingredients and mass extraction process in mushroom.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.769-777
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• 2021

Purpose: Earthquake disasters are frequently occur unpredictable situations due to various variables and unexpected situations. As a result, the work process itself is not uniform, making it difficult for public officials in the disaster safety department to familiarize themselves with the earthquake field manual. This paper is specifically and accurately grasp the current work situation conducted by the Disaster and Safety Countermeasures Headquarters of the Gyeongsangbuk-do Office and present a plan for designing serious game scenarios necessary for field manual learning. Method: In this study, scenarios were designed based on the GBS(Goal Based Scenario) model, and in the process of assigning missions and roles based on the Gyeongsangbuk-do earthquake field manual, public officials related to earthquakes were able to acquire knowledge and skills to solve practical tasks. Result: Scenario data of the proposed technique was implemented as a systematic procedure by processing various earthquake-related information into logical data and simplifying and abstracting it for game expression for earthquake situation training. Conclusion: In the event of an earthquake due to learning through serious games, related public officials of Gyeongsangbuk-do provincial are expected to be able to respond quickly to various earthquake disasters.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.91-103
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• 2022

Purpose: After COVID-19, changes in the educational ecosystem take place and fire service academy education system have shifted from face-to-face into non fact-to-face. So, the educational effect of fire officials is decreased and the satisfaction level is also decreased. In this study, we want to examine the current status of non-face-to-face real-time remote education and supplement the problems to improve the educational methods, the educational environment, etc. Method: This study is an independent variable that affects non-face-to-face real-time remote education, consisting of education system environment, self-efficacy of computers, contents (education contents, structure, design, etc.), and proper interaction. A dependent variable was selected with satisfaction for non-face-to-face real-time remote education. In addition, it was selected and analyzed as an active property of learning motivation and learning attitude as control variables. Result: The better the content and the more active the learning motivation and the attitude toward learning, the higher the satisfaction of non-face-to-face real-time remote education, and the more active the learning motivation and the attitude toward learning, the more positive the computer self-efficacy and the satisfaction of learning Conclusion: In order to increase the satisfaction of non-face-to-face real-time education due to COVID-19, education designers or professors need to provide non-face-to-face education contents that can increase the aggressiveness of their learning motivation and learning attitude, and to increase the satisfaction of education for learners by increasing computer self-efficacy through pre-education of non-face-to-face education systems.

• Journal of Industrial Convergence
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• v.20 no.6
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• pp.83-92
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• 2022

This study is to investigate the factors affecting post-traumatic stress disorder (PTSD) symptoms among hospital nurses during the COVID-19 pandemic in Korea. Cross-sectional, descriptive design is used in this study. Data collection was completed through an online self-administered survey from December 2020 to January 2021 among 180 registered nurses dealing with COVID-19 patients at hospitals. This survey includes socio-demographic questions, including a 22-item PTSD questionnaire, a 14-item type D personality questionnaire, a 25-item resilience questionnaire, and a 23-item Social Support Scale questionnaire. 56.1% of the subjects in this study were at risk of PTSD. In the high-risk group for PTSD, resilience and social support were lower than those in the low-risk group for PTSD. But there was no statistically significant difference in both variables (resilience t=0.21, p=.836, social support t=1.07, p=.287). However, education (OR = 2.23, p= .041) and type D personality (OR = 3.67, p < .001) were significant factors for PTSD symptoms. The results of the study can be utilized to recognize PTSD in nurses by identifying factors influencing PTSD during epidemics such as COVID-19, and to apply management systems such as psychological programs to help overcome them.

• The Korean Journal of Coaching Psychology
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• v.6 no.1
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• pp.33-55
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• 2022

This study examined the effects of 1:1 online coaching for college students on self-directed learning, learning motivation and time management. The coaching program consisted of motivation, behavior and cognitive control, which are sub-factors of self-directed learning. Total of 7 sessions(80 minutes per session) were progressed. Seven participants who wanted coaching, out of the total 16 participants, were assigned to the experimental group. A non-equal control group experimental design was applied. Dependent variables were measured by questionnaire before and after the coaching, and satisfaction survey and post-interview were also conducted after the coaching. ANCOVA was adopted to test the effectiveness of the program. The statistical results indicated that the learning coaching of this study has positive effect on self-directed learning and learning motivation of university students, and has partially positive effect on time management. In addition, the mean of satisfaction survey was 4.85 and participants showed positive responses on the program.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.4
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• pp.428-434
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• 2022

This study intends to develop an eco-friendly concrete panel mixed with biochars. Experiments about mechanical and thermal properties were conducted on porous biochar concrete, which has insulation and carbon-capture performance. The concrete has a mixing ratio of 0, 5, 10, and 15 % for biochar and a water-binder ratio of 0.35. The unit weight, porosity, and permeability were measured to evaluate the mechanical characteristics. From the results, as the biochar mixing rate increased, the porosity and the permeability increased, but the unit weight decreased. Even though a decreased trend was observed in the compressive strength results, they satisfied the design standard. Since the thermal conductivity was decreased during the increase of contents, biochar could be considered an excellent material for insulation performance. In addition, regression analyses were conducted regarding the relationship of unit weight with porosity, compressive strength with thermal conductivity, and porous with thermal conductivity. From the regression, significant variables for expanding the scope of the application of biochar were presented.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.397-404
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• 2021

The web-based crowdfunding platform provides small-cap companies the opportunity to reduce financial risks and to reliably produce new products through pre-orders. Meanwhile, crowdfunding projects are also helping companies as a channel to test new products before mass production. Despite these advantages, from the point of view of businesses and consumers, it is true that web-based crowdfunding platforms have limitations in the retail environment. For example, the limited social elements of a web-based platform are somewhat in conflict with the basic characteristics of crowdfunding projects - which inevitably demand high social influences for the success. As such, understanding the mechanisms of social factors of crowdfunding platforms from the consumers' perspective is important. Therefore, in this study, we empirically tested the effect of social factors of crowdfunding platform on consumer participation and evaluation. Based on the Social Influence Theory and Social Presence Theory, we developed a conceptual framework where the social group size and social presence of other backers were the independent variables and the purchaser's intention to participate as the dependent variable. In the results, the size of the social group size and the perceived social presence have a significant positive effect on purchaser's participation intent. In addition, the social presence had a greater influence on the purchaser's intention to participate than the size of the sponsor's social group. We believe that our findings contribute to the extant literature by empirically demonstrating the valid effect of social factors of crowdfunding platforms on consumer evaluations.