• Resources Recycling
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• v.29 no.6
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• pp.98-103
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• 2020

In this study, the depression behavior of zinc sulfate on the sphalerite with the addition of potassium butyl xanthate was investigated to clear the relationship between zinc sulfate and xanthate in depression of sphalerite. As a result of the experiment, it was confirmed that the depress effect of zinc sulfate on the sphalerite declined with the increase of its addition amount. From the results of SEM-EDS and FT-IR analysis, it was found out that the amorphous precipitate of metal xanthate (Zn-BX) was formed in sphalerite concentrate, when the solubility product of [Zn+]·[BX] in the pulp solution exceeded 3.71×10-11, which is the solubility of Zn-butyl xanthate. It is considered that the Zn-butyl xanthate had a negative effect on the depression of sphalerite.

• Journal of the Korean School Mathematics Society
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• v.24 no.1
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• pp.83-105
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• 2021

In this paper, we analyzed the misconceptions and errors incurred during factorization learning. We also examined whether online individualization classes had a positive effect on students' mathematical achievement. The experiment was conducted for 4 weeks (16 times in total) on middle school juniors in rural areas of Gyeonggi Province, where the influence of private extra education was small. In the class, the 'Google Classroom' was used as a LMS, the video lecture was uploaded to YouTube, and the teacher interacted with the students through "Zoom" and "Facetalk". In the online class situation, students' assignments and test answers were checked in real time through 'Google Classroom', and immediate feedback was provided to the experimental class group's students. However, for the control group students, feedback was provided only to those who desired. A total of 7 achievement evaluations were conducted in the order of pre-test, formative evaluation (5 times), and post-test to confirm the change in students' ability improvement and achievement. Through the formative evaluation analysis, it was possible to grasp the types of errors and misconceptions that occured during the factorization process. Students' errors were divided into four types: theorem or definition distortion error, functional errors such as calculation, operation, and manipulation, errors that do not verify the solution, and no response. As a result of ANCOVA, the two groups did not show any difference from the 1st to 4th formative assessment. However, the 5th formative assessment and post-test showed statistically significant differences, confirming that online individualization classes contributed to improvemed achievement.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.3
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• pp.31-39
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• 2011

The flowfield in a solid rocket motor was simulated at the wall-injection test model, which has a fin-slot grain and submerged nozzle, and visualized by a smoke-wire. The high speed CCD camera captured the visualized images around the nozzle inlet through the grain center port. The vortical tube structure and circumferential flow patterns at the nozzle throat were visualized. The radial momentum transfer caused by the shear-interactions of slot-outlet flow, fin-base flow and grain port flow from upstream worked as the source of these phenomena.

• The Journal of Information Systems
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• v.33 no.2
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• pp.169-189
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• 2024

Purpose The purpose of this study is to identify the influence relationship between BJ interactivity, explicitness of paid advertisements, flow, and product attitude in YouTube muk-bang, and to determine whether there are gender differences in the relationship between them. Design/methodology/approach In this study, an online survey was conducted targeting college students who watch YouTube muk-bang content using a questionnaire form provided by Google. 115 questionnaires were collected from April 1 to 15, 2024, and after excluding 15 insincere responses, a total of 100 questionnaires were used in the final analysis. Findings The results of the empirical analysis are as follows. First, the explicitness of including paid advertising was confirmed to have a significant impact on both flow and product attitude. Second, while BJ interactivity had a significant effect on flow, it was confirmed that it had no significant effect on product attitude. Third, flow was confirmed to have a significant impact on product attitude, and as a result of confirming the moderating effect due to differences between genders in the relationship between the variables set in this study, it was confirmed that there was no moderating effect.

• Composites Research
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• v.23 no.3
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• pp.13-18
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• 2010

One of the biggest challenges in the nano-field is how to effectively disperse nano-scale particles, especially CNTs, which are strongly agglomerated by intermolecular van der Waals forces. This study suggests a new method, discharge flocking, in order to disperse nano-scale particles effectively, which combines corona discharge phenomenon and a traditional electrostatic flocking process. In order to evaluate the discharge flocking process, composite specimens were fabricated by the process and RFI(resin film infusion) process, and then the mechanical and electrical properties of the specimens were measured and compared. Moreover, the evaluation of gas discharge effect on the CNTs and epoxy was performed to compare the mechanical and electrical properties of the composite specimens including the plasma treated CNTs. The experimental results showed that the electrical and mechanical properties of the specimens fabricated by the discharge flocking process were similar to those of the RFI process. In addition, plasma treated CNTs were not affected by gas discharge during the discharge flocking process.

• Journal of the Korean Vacuum Society
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• v.22 no.4
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• pp.204-210
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• 2013

In order to improve osseointegration for biomedical implants, it is crucial to understand the interactions between nanostructured surfaces and cells. In this study, $TiO_2$ nanowires were prepared via Vapor-Liquid-Solid (VLS) process with Sn as a metal catalyst in the tube furnace. Nanowires were grown with $N_2$ heat treatment with their size controlled by the agglomeration of Sn layers in various thicknesses. MC3T3-E1 (pre-osteoblast) were cultured on the $TiO_2$ nanowires for a week. Preliminary results of the cell culture showed that the cells adhere well on the $TiO_2$ nanowires.

• Applied Chemistry for Engineering
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• v.24 no.5
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• pp.551-557
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• 2013

In the present study, pristine carbon nanotube (p-CNT) and thiolated carbon naotube (t-CNT) electrodes were investigated to improve their detectabilities for cadmium (Cd) and lead (Pb). In addition, we evaluate which reaction mechanism is used when the electrolyte contains both Cd and Pb metals. Square wave stripping was employed for analyzing the sensitivity for the metals. A frequency of 30 Hz, a deposition potential of -1.2 V vs. Ag/AgCl and a deposition time of 300 s were used as optimal SWSV parameters. t-CNT electrodes show the better sensitivity for both Cd and Pb metals than that of p-CNT electrodes. In case of Cd, sensitivities of p-CNT and t-CNT electrodes were $3.1{\mu}A/{\mu}M$ and $4.6{\mu}A/{\mu}M$, respectively, while the sensitivities for Pb were $6.5{\mu}A/{\mu}M$ (p-CNT) and $9.9{\mu}A/{\mu}M$ (t-CNT), respectively. The better sensitivity of p-CNT electrodes is due to the enhancement in the reaction rate of metal ions that are facilitated by thiol groups attached on the surface of CNT. When sensitivity was measured for the detection of Cd and Pb metals present simultaneously in the electrolyte, Pb indicates better sensitivity than Cd irrespective of electrode types. It is ascribed to the low standard electrode potential of Pb, which then promotes the possibility of oxidation reaction of the Pb metal ions. In turn, the Pb metal ions are deposited on the electrode surface faster than that of Cd metal ions and cover the electrode surface during deposition step, and thus Pb metals that cover the large portion of the surface are more easily stripped than that of Cd metals during stripping step.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.211-227
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• 2020

This study intends to analyze the storytelling strategy of EBS's YouTube channel , which has been creating a remarkable cultural phenomenon since April 2019, and to examine the potential for its transition to transmedia franchise. Based on Henry Jenkins'seven principles of transmedia storytelling, shows satisfactory relevance in all but 'multiplicity'out of the 10 capacities consisting of the principles. In particular, was found excellent in terms of core capacities such as 'spreadability', 'immersion', 'worldbuilding', 'continuity', 'drillability' and 'performance'. In addition, critical discourse analysis(CDA) in sociocultural practice dimension of the keywords of the related news articles has discovered that is strongly linked to the following five values: 'social integration', 'resistance against authoritarianism', 'self-dignity and reasonable individualism', 'gender neutrality' and 'ecologism', indicating the reason why the work has been able to resonate so extraordinarily with participants across all generations. By answering the two chosen research questions, this study has proved that has high potential to be successful in evolving into transmedia franchise, while keeping building a new realm of edutainment storytelling by cleverly exploiting EBS's unique identity as a public education broadcaster. is viewed as an exceptional property capable of advancing transmedia storytelling in the local market; thus, productive arguments and contemplation over its evolution in storytelling needs to continue so that it can maintain a long-lasting positive influence.

• Journal of the Korea Convergence Society
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• v.13 no.3
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• pp.239-253
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• 2022

The purpose of this study is to have college students who took 'University Character Education Using YouTube Videos', which was opened as a liberal arts course in college, directly produce UCC assignments with the theme of personality. Despite the recent paradigm shift in learner-centered education, teacher-centered education still hinders learners' motivation to participate in classes. To solve this problem, a learner-led UCC production process is necessary for the practice of effective learner-centered education. For this purpose, a phenomenological research method was applied. The research participants were 10 students, in-depth interview was used for data collection, and Colaizzi's research method was selected for data analysis. As a result of the analysis, 9 themes, 4 theme clusters, and 2 categories were derived. The results are as follows. First, they recognized that the UCC assignments were a field of maturity, such as practicing the right thoughts and actions, and re-establishing the concept of character. Second, they said that the UCC production process was an opportunity to increase their self-esteem. Third, they showed a more mature personality by recognizing that the UCC assignments became a chance to pay attention to others beyond themselves. Fourth, they had the greatest difficulty in selecting a topic while carrying out the UCC project, and they were experiencing the limitations of high-quality projects due to the technical immaturity of UCC production. Finally, this study was concluded by discussing the educational implications based on the results. These results provide a suggestion that more effective character education can be expected when tasks led by learners will be developed and an interactive arena where students can be shared are provided.

• Journal of Korea Entertainment Industry Association
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• v.13 no.3
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• pp.13-25
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• 2019

Since reaching the top in the Billboard Main Album Chart 'Billboard 200' with Love Yourself: Tear in May of 2018, BTS once again took first place after just three months in the 'Billboard 200'(September 3, 2018) with the repackaged album Love Yourself: Answer. It opened the doors to the 'Hallyu 4.0' by conquering the main Billboard Chart with a song sung in Korean. BTS rose to the top on the 'Billboard 200' twice, thus being recognized globally for their musical talent(song, dance, promotion, etc.), and took their place in the mainstream music market of the world. BTS moved away from intuitive interaction such as mysticism, abnormality, irregularity, etc. but instead created their own world(BTS Universe) with fans around the world through two-directional communication such as consensus, sharing and co-existence. They are recognized as artists that went beyond being an idol group that simply released a few hit songs that had now elevated popular music to a new form of art. In result, they retained a highly loyal global fan base(A.R.M.Y.) and they are continuously creating good influence with them. This study analyzed the success factors of BTS using the S-M-C-R-E model as follows. ① Sender: BTS'7-person 7-colors fantasy and 'All-in-one storytelling' strategy of producer Bang Shi-hyuk ② Message: Create global consensus of 'you' rather than 'me' ③ Channel: Created real-time common grounds with global fans through social network platforms such as Youtube, Facebook and Instagram ④ Receiver: Formed highly loyal global fandom(A.R.M.Y.) that extends outside of Korea and Asia ⑤ Effect: Created additional economic value and spread good influence