• Journal of the Korean School Mathematics Society
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• v.22 no.1
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• pp.1-21
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• 2019

Mathematics is one of the subjects in which learners seriously experience under-achievements in school education. Middle school level mathematics especially plays such a role as a bridge between elementary level informal mathematics and high school level formal mathematics that learners' under-achievements in the middle school level mathematics may yield more serious under-achievements later. Therefore it is crucial to prevent learners' later under-achievements that we analyze the status of under achievements including analysing various under-achievers' errors in the middle school level mathematics. From this point of view, we analysed errors of mathematics under-achievers in understanding the concept of the square root of positive numbers and related calculations in this paper. As the results of our research, we found some unexpected errors of 'some mathematics under-achievers regarding the mathematical symbol ${\surd}$ of square root as a parenthesis ( ), and others interpret $x=-2{\pm}{\sqrt{10}}$ as x=-2 or ${\pm}{\sqrt{10}}$.' that suggest the necessity of more various and in-depth discussions and researches of analysis on learners' errors and misconceptions in all areas of school mathematics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.52-60
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• 2021

The aim of this study was to derive a new trend by analyzing installations using 3D printing that are out of the limits of size and design according to the trends of developing 3D printing technology. This paper classified the types of installations using 3D printing and analyzed them with two trends: the trend of design and the trend of output. The trends of installations using 3D printing derived from this study are as follows. First, as the implementation of design through an algorithm is accomplished, the transformation appears with the atypical design that is prominent in complex expression. Second, Robotics and FDM 3D Printing is fused, which is changing the existing paradigm. Therefore, the production and utilization of installations using 3D printing proceeded at a faster pace through the interaction between the algorithm design method and freeform 3D printing technology. This study was conducted on installations using 3D printing around the world and played a basic role in the research on the production of installations using 3D printing along with domestic 3D printing technology to be developed in the future. Follow-up studies in various aspects, such as materials and combination methods, will be needed.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.347-358
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• 2021

The purpose of this study was to investigate the stage of concern and use level of early childhood teachers' STEAM, and to find out whether there is a difference in the stage of concern according to individual teachers' variables. The subjects were 242 teachers in charge of 3-5 years old kindergarten and daycare center in G city. The research tool was the stages of concern questionnaire (SoCQ). The collected data were converted to relative intensity by applying percentile conversion chart in the guidelines, and this was expressed as a concern profile graph, and t-test and ANOVA were performed to find out the difference in concern according to teacher's background variables. The research results are as follows. First, the stage of concern in early childhood teachers' STEAM was identified as a critical non-user profile. Second, the stage of concern in the teacher's STEAM was judged as a person who did not use, or was implemented for less than 2 years, and was a non-user or a novice. In addition, it was found that most of the teachers did not receive formal education for STEAM. third. There were differences in the educational background, career, current execution status of teachers, whether or not to take related courses in pre-service teacher education, and whether to plan for future implementation. And there were no differences in the majors and institution types of teachers. Based on these results, a support plan for changing the stage of concern of teachers about STEAM and improving the level of use was suggested.

• The Journal of the Korea Contents Association
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• v.21 no.5
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• pp.70-83
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• 2021

The issue of predicting the relationship between humans and AI robots is a 'strong AI' problem. Many experts predict the tragic ending which is a strong AI with superior thinking ability than humans will conquer humans. Due to the expectations of AI robots are projected onto media, the 'morally good AI' that meets human expectations is an important issue. However, the demand for good AI and the realization of perfect technology is not limited to machines. Rather, it appears as a result of putting all responsibility on humans, driving humans into immoral beings and turning them into human and human problems, which is resulting in more alienation and discrimination. As such, the result of technology interacts with the human being used and its properties are determined and developed according to the reaction. This again affects humans. Therefore, AI technology that considers human emotions in consideration of interaction is also important. Therefore, this study will clarify the process that the demand for 'Good AI' in the relationship of AI to humans with Randall Collins' Interaction Ritual Chain. Emotional energy in Interaction Ritual Chain has explained the formation of human bonds. Also, the methodology is a type of thinking experiment and explained through Janet and surrounding characters in the TV show .

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.428-438
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• 2022

The purpose of this study was to examine the modern implication and religious value of the Medicine Buddha faith. Accordingly, the theoretical background of Medicine Buddha faith was reviewed based on various literature, including Bhaisajyaguru Sutra, a representative literature on Medicine Buddha, and the two key goals of Medicine Buddha faith were set up and analyzed. As a result of this study, the modern implication and religious value of the Medicine Buddha faith were presented as follows. First of all, it is the modern implication of the Medicine Buddha faith. First, the Medicine Buddha faith promotes a shift in the perspective that disease is the subject of healing, not treatment. Second, the Medicine Buddha faith expands diseases not only to medical diseases but also to disabilities and makes them an object of healing. Third, the Medicine Buddha faith promotes healing through performance that strengthens the positivity of the mind. Next is the religious value of the Medicine Buddha faith. First of all, the Medicine Buddha faith has strong religious acceptance. Second, the Medicine Buddha faith is characterized by being accepted by modern people beyond religion and sect. Based on the results of this study, this study made suggestions to improve the quality of life of modern people suffering from pain in their daily lives due to diseases and unnatural death.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.581-587
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• 2022

The leather industry generates a large amount of hazardous leather waste of various types every year. Among them, shaving scrap is difficult to recycle because it contains chromium ions. Many studies in recent years have shown that shaving scraps can be processed into various types of valuable products, such as adsorbent, filler, and poultry feed. In this study, collagen peptides were extracted from shaving scraps and structurally modified to be developed as new materials with improved physicochemical properties. First, the chromium ions contained in the shaving scraps were removed using a sodium hydroxide solution, and purified through concentration and low-temperature crystallization. The purified collagen peptide was used to prepare the powder using a spray dryer. The extracted collagen peptides were structurally modified by introducing double bonds by reacting with methacrylic anhydride (MAA), and the product was confirmed by ¹H NMR spectroscopy. Next, a copolymer was prepared by redox polymerization of the modified collagen peptide (MCP) and 2-ethylhexyl acrylate (2-EHA). The structure of the copolymer was qualitatively confirmed by FT-IR. In conclusion, this study confirmed that collagen peptides can be extracted from shaving scrap and converted into new eco-friendly materials through certain treatments.

• Journal of Food Hygiene and Safety
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• v.37 no.1
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• pp.21-28
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• 2022

In this study, a new lactic acid bacterium (LAB) that could produce gamma-aminobutyric acid (GABA) was isolated from Oenanthe javanica (water celery) and identified as an Enteroccoccus casseliflavus strain. Until recently, there have been many studies on the gamma-aminobutyric acid producing lactic acid bacterium, as well as on some lactic acid bacterium in Enteroococcs genus, but none on the species E. casseliflavus. Therefore, in the purpose of finding the optimal conditions for GABA production of E. casseliflavus PL05, the effects of several conditions including the type of mediums, growth temperatures, initial pH, growth time, L-mono sodium glutamate (MSG) concentration, and carbon source were tested. The study revealed that the PL05 strain grew better in the Brain Heart Infusion (BHI) medium than in the Man, Rogosa, and Sharpe (MRS) or Tryptic Soy Broth (TSB) medium. Also, similar results were obtained with GABA production conditions. As a result of analysis on the GABA production yield by concentration of MSG, a GABA substrate, the highest production was found at 7% of MSG concentration. However, since similar level of production was found at 5%, it is considered to be more efficient to use 5% MSG concentration. The analysis on the growth and GABA production yield by carbon sources showed the highest results when maltose was used. From the final test under the optimal conditions found, 140.06±0.71 mM of GABA was produced over 24 hours with the conversion rate of 78.95%. Lastly, from the sensitivity analysis on the 10 different antibiotics, including vancomycin, it was found that there were not confirmed cases of resistance.

• Journal of Practical Agriculture & Fisheries Research
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• v.5 no.1
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• pp.64-76
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• 2003

This study was conducted in order to find out the basic data and informations for the accidents for repairing of agricultural machines. This study was summarized as fellows : 1. Among the total repair work, the ratio of repair accident was 68.9% and the accident ratio with power tiller, tractor, and combine was 84.8%. The accident occurred frequently in April to May and September to October because of frequent use of machines during this months. The accidents occurred often of ten to eleven and two to three afternoon in a day. 2. The 36.3% of the accident types was farming machines and the 60.4% of the accident occurred in yard of repair shop. The 34.4% of accident was caused by people, 26.2% by machines, 24.9% by environmental factors, and 14.5% by others. 3. In accident damage, human damage was 98.4% and economic damage was 43.6%. There was only 40.2% in having agricultural machinery insurance and 22.5% of research applicant answered that they would not have insurance in the future. 4. The 58.2% of the injured parts occurred in fingers, hands, wrists, or arms and the 74.4% of the damage types were bruise, prick or abrasion. The damaged parts of machinery were belt of power transmission device, chains, sharpened knives, narrow mechanism or cultivating knives for rotary. 5. The average days of medical treatment for casualty was 15.5 days and the average expense of medical treatment per person was 189,200 won. The days of temporary rest and the economic damage per person due to accident were 12.8 days and 469,300 won.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.2
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• pp.295-303
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• 2023

As the cloud computing market grows, a variety of cloud services are now reliably delivered. Administrative agencies and public institutions of South Korea are transferring all their information systems to cloud systems. It is essential to develop security solutions in advance in order to safely operate cloud services, as protecting cloud services from misuse and malicious access by insiders and outsiders over the Internet is challenging. In this paper, we propose a zero trust model for cloud storage services that store sensitive data. We then verify the effectiveness of the proposed model by operating a cloud storage service. Memory, web, and network forensics are also performed to track access and usage of cloud users depending on the adoption of the zero trust model. As a cloud storage service, we use Amazon S3(Simple Storage Service) and deploy zero trust techniques such as access control lists and key management systems. In order to consider the different types of access to S3, furthermore, we generate service requests inside and outside AWS(Amazon Web Services) and then analyze the results of the zero trust techniques depending on the location of the service request.

• Knowledge Management Research
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• v.24 no.1
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• pp.1-29
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• 2023

The COVID-19 pandemic has accelerated digital transformation across all industries and daily life. Edutech is spreading in the education field, also bringing changes in university education. Non-face-to-face online-only classes at universities have spread after the COVID-19 pandemic physical distancing started. Online-only or real-time online classes showed diverse educational imitations. 'Metaverse' started to attract attention as a learning space and community activity support platform that may solve the limitations of online education and communication. It is time to prepare an introduction strategy for the actual application of education using metaverse. This study, first, by examining previous studies and cases of metaverse application, and second, establishing a metaverse introduction framework based on the technology lifecycle model and the innovation diffusion theory. Finally, we provide an introduction strategy in steps, a specialized introduction plan according to the main users is established and presented as a scenario. We expect that this study will provide the theoretical background of the new technology introduction and the spread of metaverse research. Also, we present an efficient introduction strategy, the basis for a service model, and a practical basis for the university's value-added strategy.