• Journal of Life Science
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• v.29 no.2
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• pp.173-180
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• 2019

Amyloid ${\beta}$-protein ($A{\beta}$) is the principal component of senile plaques characteristic of Alzheimer's disease (AD) and elicits a toxic effect on neurons in vitro and in vivo. Many environmental factors, including antioxidants and proteoglycans, modify $A{\beta}$ toxicity. It is worthwhile to isolate novel natural compounds that could prove therapeutic for patients with AD without causing detrimental side effects. In this study, we investigated the in vitro neuroprotective effects of the ethyl acetate fraction of methanol extract of Ophiophogon japonicas (OJEA fraction). We used an MTT reduction assay to detect protective effects of the OJEA fraction on $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells. We also used a cell-based ${\beta}$-secretase assay system to investigate the inhibitory effect of the OJEA fraction on ${\beta}$-secretase activity. In addition, we performed an in vitro lipid peroxidation assay to evaluate the protective effect of the OJEA fraction against oxidative stress induced by $A{\beta}_{25-35}$ in PC12 cells. The OJEA fraction had strong protective effects against $A{\beta}_{25-35}$-induced cytotoxicity to PC12 cells and was strongly inhibitory to ${\beta}$-secretase activity, which resulted in the attenuation of $A{\beta}$ generation. In addition, the OJEA fraction significantly decreased malondialdehyde (MDA) content, which is induced by the exposure of PC12 cells to $A{\beta}_{25-35}$. Our results suggested that the OJEA fraction contained active compounds exhibiting a neuroprotective effect on $A{\beta}$ toxicity.

• Microbiology and Biotechnology Letters
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• v.49 no.1
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• pp.111-119
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• 2021

A bacterial strain isolated from a Malva verticillata leaf was identified as Bacillus velezensis MV2 based on the 16S rRNA sequencing results. Complete genome sequencing revealed that B. velezensis MV2 possessed a single 4,191,702-bp contig with 45.57% GC content. Generally, Bacillus spp. are known to produce diverse antimicrobial compounds including bacteriocins, polyketides, and non-ribosomal peptides. Antimicrobial compounds in the B. velezensis MV2 were extracted from culture supernatants using hydrophobic interaction chromatography. The crude extracts showed antimicrobial activity against both gram-positive bacteria and gram-negative bacteria; however, they were more effective against gram-positive bacteria. The extracts also showed antifungal activity against phytopathogenic fungi such as Fusarium fujikuroi and F. graminearum. In time-kill assays, these antimicrobial compounds showed bactericidal activity against Bacillus cereus, used as indicator strain. To predict the type of antimicrobial compounds produced by this strain, we used the antiSMASH algorithm. Forty-seven secondary metabolites were predicted to be synthesized in MV2, and among them, fourteen were identified with a similarity of 80% or more with those previously identified. Based on the antimicrobial properties, the antimicrobial compounds may be nonribosomal peptides or polyketides. These compounds possess the potential to be used as biopesticides in the food and agricultural industry as an alternative to antibiotics.

• Journal of The Korean Association For Science Education
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• v.41 no.2
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• pp.145-154
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• 2021

This study aims to investigate teachers' perceptions of the composition of high school science elective courses ahead of the 2022 curriculum revision, and to derive implications for the organization of the 2022 revised science curriculum in preparation for the full implementation of the high school credit system. To this end, a survey was conducted by randomly sampling high schools across the country. A total of 192 science teachers responded to the questionnaire. In addition, 12 high school science teachers were selected as a focus group, and in-depth interviews were conducted to investigate opinions on the restructuring of elective courses in science. Main research results include 129 (67.2%) science teachers in the survey answered that the current 2015 curriculum's science and elective courses system should be maintained. In the next curriculum, when reconstructing science elective subjects, it is necessary to provide an opportunity to experience the entire contents of each science field through Science I·II system as before, and to ensure student choice in preparation for the credit system. In addition, the opinion that general elective subjects should be organized to include all the contents of science I and II subjects was the highest. Through in-depth interviews, science teachers emphasized that the current science I subject system allows access to the content areas of science as much as possible as the number of subjects is small, and that subjects, such as physics, where the hierarchy of concepts is important, should deal with important content within one subject rather than divided by area. On the other hand, in the current I subject system, there is no subject for liberal arts students to choose from, so teachers suggested that science electives should be organized by subdividing each content area. Based on the research results, the necessity of organizing high school science elective courses in consideration of the purpose of the high school credit system, ways to organize science-convergence elective courses as subjects for all students regardless of career aptitude, ways to organize science-career elective courses, and ways to organize science elective courses in connection with the college admission system were proposed.

• Journal of Intelligence and Information Systems
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• v.29 no.1
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• pp.79-105
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• 2023

Due to unprecedented extreme weather events such as global warming and climate change, many parts of the world suffer from severe pain, and economic losses are also snowballing. In order to address these problems, 'The Paris Agreement' was signed in 2016, and an intergovernmental consultative body was formed to keep the average temperature rise of the Earth below 1.5℃. Korea also declared 'Carbon Neutrality in 2050' to prevent climate catastrophe. In particular, it was found that the increase in temperature caused by greenhouse gas emissions hurts the environment and society as a whole, as well as the export-dependent economy of Korea. In addition, as the diversification of transportation types is accelerating, the change in means of choice is also increasing. As the development paradigm in the low-growth era changes to urban regeneration, interest in idle railway sites is rising due to reduced demand for routes, improvement of alignment, and relocation of urban railways. Meanwhile, it is possible to partially achieve the solar power generation goal of 'Renewable Energy 3020' by utilizing already developed but idle railway sites and take advantage of being free from environmental damage and resident acceptance issues surrounding the location; but the actual use and plan for these solar power facilities are still lacking. Therefore, in this study, using the big data provided by the Korea National Railway and the Renewable Energy Cloud Platform, we develop an algorithm to discover and analyze suitable idle sites where solar power generation facilities can be installed and identify potentially applicable areas considering conditions desired by users. By searching and deriving these idle but relevant sites, it is intended to devise a plan to save enormous costs for facilities or expansion in the early stages of development. This study uses various cluster analyses to develop an optimal algorithm that can derive solar power plant locations on idle railway sites and, as a result, suggests 202 'actively recommended areas.' These results would help decision-makers make rational decisions from the viewpoint of simultaneously considering the economy and the environment.

• Journal of agriculture & life science
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• v.50 no.5
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• pp.163-172
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• 2016

Four growing Hanwoo cattle weighing 200±11.7kg were used within 4×4 Latin square design to establish nutrient requirements for Hanwoo growing steers under severe heat stress. The steers were fed four different energy level diets; 100%(control), 100%(E100), 115%(E115) and 130%(E130) of energy levels of growing Hanwoo steers based on total digestible nutrient level suggested by the Korea Feeding Standard for Hanwoo using timothy hay and commercial concentrate. The steers in the control were housed with no stress, whereas the steers in the other groups were under severe heat stress. The severe heat stress significantly decreased(p<0.05) true digestibility of dry matter(i.e. control 81.5% vs E100 79.1, E115 77.0 and E130 76.0, respectively). The severe heat stress and different energy intake levels did not affect blood physiological metabolites and body temperature of the growing steers. Based on changes in average daily gain by different energy intake level, the equation(Y=0.235X+115.03) of energy requirement of growing Hanwoo steers without changes in body weight was calculated, indicating that, compared with the present energy intake suggested by Korean feeding standard, 15.03% of dietary energy for maintenance of growing Hanwoo steers under severe heat stress should be increased.

• Journal of the Korean Institute of Landscape Architecture
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• v.52 no.2
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• pp.64-78
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• 2024

Storytelling is a communication technique to express and convey the story using various media, where the audience accepts the story, reinterprets the topic and interacts with the storyteller. It was assumed that the user's significance and awareness about the storytelling technique applied to historical theme parks would have an impact on the satisfaction of using the theme park and intention to revisit. In this study, it was purposed to derive the structural factors of spatial storytelling in historical theme parks, and to understand the impact of user's awareness and constituent factors on user responses. Based on previous researches, the structural factors of spatial storytelling in historical theme parks were derived related to theme, experientiality, unusualness, educationalness, unity, expressiveness, interactivity, and interest, and for which the users' awareness was surveyed. The survey was conducted targeting the users of Samguk Yusa Theme Park located in Gunwi-gun, Gyeongsangbuk-do, where the collected data was analyzed using EXCEL2020 and SPSS 21.0 statistical programs, and the results are as follows: First, the spatial storytelling technique applied as a conveying method of the theme of Samguk Yusa Theme Park affects users' satisfaction and intention to revisit, and most respondents responded that the storytelling was significant. Second, it showed that the significance of unusualness and educationalness among the awareness of significance of the spatial storytelling constituent factors of Samguk Yusa Theme Park has a significant impact on user's satisfaction, and the significance of unusualness, interactivity, educationalness, and interest has a significant impact on intention to revisit. Third, it showed that the awareness of interest, theme, and unity has a significant impact on user's satisfaction depending on the user's awareness of spatial storytelling constituent factors of Samguk Yusa Theme Park, and the awareness of interactivity and experientiality has a significant impact on intention to revisit. This study is meaningful in quantitative analysis and interpretation of the influence of storytelling on user's response to historical theme parks by the exploratory analysis of characteristic factors and spatial storytelling constituent factors on historical theme parks and deriving the structural factors of spatial storytelling in historical theme parks.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.3
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• pp.13-21
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• 2017

The Cho-yeon Pavilion located in the Wangdae village in Samcheong-ri, Songgwang-myeon, Suncheon-si, was transformed into a place of refuge, a shrine, a vacation home, a lecture hall for kings. Based on the change, the current study has explored the periodic changing placeness and the transformation of cultural landscape and has figured out the meaning. The result of this study is as follows. First, "Cho-yeon", named by Yeonjae Song, Byeong-Seon, originated from Tao Te Ching of Lao Tzu. The concept is found not only in the Cho-yeon Pavilion in Suncheon but also in various places, such as, the Cho-yeon-dae in Pocheon, of the Cho-yeon-dae in Gapyeong, of the Cho-yeon-dae of the embankment behind the Gioheon of Changdeok-gung Garden, Cho-Yeon-Mul-Oe old buildings, including Jung(亭), Dae(臺), Gak(閣), of Ockriukag in Yuseong, etc. This shows that taoistic Poongrhu was naturally grafted onto confucian places, which is one of the examples of the fusion of Confucianism, Buddhism, and Taoism. Second, the placeness of the Cho-yeon Pavilion area is related to a legend that King Gong-min sought refuge here at the end of the Koryo Dynasty. The legend is based on the Wangdae village(king's region), Yu-Gyeong(留京)(the place where kings stayed), rock inscription of Wang-Dae-Sa-Jeok, Oh-Jang-Dae (the place where admiral flags were planted), and the Mohusan Mountain. Third, the Cho-yeon Pavilion not only has a base(the vacation home) that reflects confucian values from the rock inscription(趙鎭忠別業, 趙秉翼, 宋秉璿) of the beautiful rock walls and torrents but also has territoriality as taoistic Abode of the Immortals (there are places where people believe taoist hermits with miraculous powers live within 1km of the pavillion: Wol-Cheong(月靑), Pung-Cheong(風靑), Su-Cheong(水靑), Dong-Cheon(洞天). The Cho-yeon Pavilion also reflects the heaven of Neo-Confucianism for, pursuing study, and improving aesthetic sense by expanding its outer area and establishing the nine Gok: Se-Rok-Gyo(洗鹿橋)., Bong-Il-Dae(捧日臺), Ja-Mi-Gu(紫薇鳩), Un-Mae-Dae(雲梅臺), Wa-Ryong-Chong(臥龍叢), Gwang-Seok-Dae(廣石臺), Eun-Seon-Gul(隱仙窟), Byeok-Ok-Dam(碧玉潭), and Wa-Seok-Po(臥石布). In sum, the Cho-yeon Pavilion is a complex cultural landscape. Fourth, the usage of the Cho-yeon Pavilion was expanded and transformed: (1)Buddhist monastery${\rightarrow}$(2)Confucian vacation home${\rightarrow}$(3)Vacation home+Taoistic Poongrhu Place${\rightarrow}$(4)Vacation Home+Taoistic Poongrhu Place+Lecture Hall(the heaven of Neo-Confucianism). To illustrate, in 7978, the place served as Buddist Monk Kwang-Sa's monastery; in 1863, Cho, Jin-Choong established a vacation home by building a shrine in front of the tomb of his ancestor; in 1864, Cho, Jae-Ho expanded its usage to a vacation home to serve ancestors as a taoistic place by repairing the pavilion with roof tiles; and after 1890, Cho, Jun-Sup received the name of the pavilion, Cho-yeon, from his teacher Song, Byeong-Seon, and used the Pavilion for a lecture hall.

• Journal of Intelligence and Information Systems
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• v.26 no.2
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• pp.27-42
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• 2020

Traditional companies with offline stores were unable to secure large display space due to the problems of cost. This limitation inevitably allowed limited kinds of products to be displayed on the shelves, which resulted in consumers being deprived of the opportunity to experience various items. Taking advantage of the virtual space called the Internet, online shopping goes beyond the limits of limitations in physical space of offline shopping and is now able to display numerous products on web pages that can satisfy consumers with a variety of needs. Paradoxically, however, this can also cause consumers to experience the difficulty of comparing and evaluating too many alternatives in their purchase decision-making process. As an effort to address this side effect, various kinds of consumer's purchase decision support systems have been studied, such as keyword-based item search service and recommender systems. These systems can reduce search time for items, prevent consumer from leaving while browsing, and contribute to the seller's increased sales. Among those systems, recommender systems based on association rule mining techniques can effectively detect interrelated products from transaction data such as orders. The association between products obtained by statistical analysis provides clues to predicting how interested consumers will be in another product. However, since its algorithm is based on the number of transactions, products not sold enough so far in the early days of launch may not be included in the list of recommendations even though they are highly likely to be sold. Such missing items may not have sufficient opportunities to be exposed to consumers to record sufficient sales, and then fall into a vicious cycle of a vicious cycle of declining sales and omission in the recommendation list. This situation is an inevitable outcome in situations in which recommendations are made based on past transaction histories, rather than on determining potential future sales possibilities. This study started with the idea that reflecting the means by which this potential possibility can be identified indirectly would help to select highly recommended products. In the light of the fact that the attributes of a product affect the consumer's purchasing decisions, this study was conducted to reflect them in the recommender systems. In other words, consumers who visit a product page have shown interest in the attributes of the product and would be also interested in other products with the same attributes. On such assumption, based on these attributes, the recommender system can select recommended products that can show a higher acceptance rate. Given that a category is one of the main attributes of a product, it can be a good indicator of not only direct associations between two items but also potential associations that have yet to be revealed. Based on this idea, the study devised a recommender system that reflects not only associations between products but also categories. Through regression analysis, two kinds of associations were combined to form a model that could predict the hit rate of recommendation. To evaluate the performance of the proposed model, another regression model was also developed based only on associations between products. Comparative experiments were designed to be similar to the environment in which products are actually recommended in online shopping malls. First, the association rules for all possible combinations of antecedent and consequent items were generated from the order data. Then, hit rates for each of the associated rules were predicted from the support and confidence that are calculated by each of the models. The comparative experiments using order data collected from an online shopping mall show that the recommendation accuracy can be improved by further reflecting not only the association between products but also categories in the recommendation of related products. The proposed model showed a 2 to 3 percent improvement in hit rates compared to the existing model. From a practical point of view, it is expected to have a positive effect on improving consumers' purchasing satisfaction and increasing sellers' sales.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2215-2224
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• 2013

This study performed empirical analysis to estimate SMEs needs in terms of business support policy by growth stages(start-up growth expansion). The subject is the SMEs in Cheonan and Asan, ChungNam and the results are as follows. First, In the initial start-up stage, management plays a key role in dealing with money, labor force, markets and technology while running the organization is a key role of the management in the expansion stage. Major policies to help SMEs grow includes money provision needed in the start-up stage, domestic marketing assistance and the provision of human resources in the growth stage, and assistance in foreign marketing and R&D in the expansion stage. Second, To achieve markets businesses aim at entering the existing and niche markets in the initial phase, and creating new markets in the growth phase. Third, Labor force for technology, sales and management planning in the start-up stage, marketing in the growth stage, and labor force for production in the expansion stage are core man- power needed. Fourth, Money for technology development, securing land for factories, organizing man power, securing markets and running the company is needed in the initial and growth stages while fund for facility investment is needed to grow in the expansion stage. Five, Regarding technology, the initial stage needs technology related to new product development, renewing existing products, improving the existing manufacturing process or developing new manufacturing process, while the growth stage needs processing techniques, and the expansion stage needs technology for developing new manufacturing process. Sixth, Making supply contracts with conglomerates, SMEs and public institutions, and sales to foreign markets are ways for SMEs to grow sales. Seventh, What SMEs wish to get includes business incubating support, R&D assistance, information exchanges, practical use of the R&D results, merchandising support, help with the land to build factories and custom-made support for management in the foundation stage while the support they want to get in the growth stage and in the expansion stage is training assistance and trial production respectively.

• Journal of Gifted/Talented Education
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• v.19 no.3
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• pp.697-727
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• 2009

The purposes of this study are to investigate Korean science teachers' perception on the science gifted education in Korea, and to investigate if there are differences on their perception among the science teachers whose institutes are different. Their institutes are divided into three groups, which are the formal schools for the gifted in science such as Science High-School, gifted education centers attached to district education authority, and general secondary schools. For the study, 266 science teachers were sampled from the schools in Busan Metro-city, Ulsan Metro-city, and Kyoungnam Province, and then questionnaire developed by the authors were administered to them. The research results are as follows. Firstly, teachers who were going to participate in special education for the gifted in science answered affirmatively, and they thought it seemed worthwhile. On the other hand teachers who were not going to participate in it, answered negatively, mentioning shortage in specialty or extra work overload. Secondly, only the Korean Educational Development Institute was too much preferred by science teachers for teacher training institute for the gifted education in science. Therefore, it is needed to extend the teacher training institutes for the gifted education in science throughout the country. Thirdly, the perception of science teachers on the constitution of a class for the gifted in science is very different among the teachers of formal schools for the gifted in science and the teachers who teach science part time when it is needed in the district institutes for the gifted education. Finally, the perception on the aims of special education for the gifted in science is very different between the teachers who teach the gifted in science and the teachers who do not teach them.