• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.4
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• pp.611-620
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• 2021

The maintenance industry is mainly progressing based on condition-based maintenance after corrective maintenance and preventive maintenance. In condition-based maintenance, maintenance is performed at the optimum time based on the condition of equipment. In order to find the optimal maintenance point, it is important to accurately understand the condition of the equipment, especially the remaining useful life. Thus, using simulation data (C-MAPSS), a prediction model is proposed to predict the remaining useful life of a turbofan engine. For the modeling process, a C-MAPSS dataset was preprocessed, transformed, and predicted. Data pre-processing was performed through piecewise RUL, moving average filters, and standardization. The remaining useful life was predicted using principal component analysis and the k-NN method. In order to derive the optimal performance, the number of principal components and the number of neighbor data for the k-NN method were determined through 5-fold cross validation. The validity of the prediction results was analyzed through a scoring function while considering the usefulness of prior prediction and the incompatibility of post prediction. In addition, the usefulness of the RUL prediction model was proven through comparison with the prediction performance of other neural network-based algorithms.

• Journal of vocational education research
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• v.33 no.3
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• pp.145-167
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• 2014

The purpose of this research is to prepare the measures for evaluating the job of horse-riding instructor and improvement related to it and for distributing horse-riding industry effectively. Forsuch, we tried to analyze job of horse-riding instructor. Inparticular, we have developed DACUM chart of horse-riding instructor through DACUM method and experts related to it. As result, we found out eight duties and hundreds of job and arranged seven duty areas in total and eighty-two executed works. In addition, as experts said, the horse-riding instructor is the one who 'instructs people learning horse-riding in horse-riding facility and manages horses, horse-riding equipment and man-power.' Such results provide the procedure of horse-riding instructor cultivation which has been presently underway with many viewpoints. Especially, there are three educational processes and subject materials related to horse-riding instructor's examination(Hipologia, Horse-treatment technique, Horse Health management). However, as result of analysis on duty, we found out that racecourse management and horse-riding education theory has been needed to be added and complemented as well. In addition, the work and duty of analysis can be used to be made use up of as work profile and specification and such data can be also made use of as standard of training and submission. Through this study there should be a necessary work to distinguish between re-drafting and role of duty in its own right related to certification of horse-riding instructor in future and it would be necessary to develop study that is able to connect them all to certificate. What is more, there should be work and measure required for rethinking of utility of certification.

• Journal of vocational education research
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• v.35 no.4
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• pp.109-129
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• 2016

Korea has recently invested much of its effort in fostering talents in scientific fields to establish a foundation for sustainable future growth. From this perspective, the ministry of education has come up with a special rule aimed at achieving the substantiality of engineering schools in universities. The ministry has been providing educational support by providing a tech-innovation center, industry-oriented education, and policies such as PRIME. Despite this support, most students in the natural science field end up being hired in fields not related to their majors. There has been a growing opinion regarding the need for career education for these students. In this research, based on a social cognitive career theory (SCCT) model that provides a comprehensive understanding of career development, this research would like to practically examine the relationship among college students' career preparation behaviors and influencing variables, such as grit, career decision-making self-efficacy, outcome expectation, and major interest. Data from 153 natural-science majors at A college in Korea were collected and analyzed using path analysis. The result was that the data strongly supported the model explaining the relationship between career preparation behaviors and influencing variables. Based on this result, we propose that career education that can promote grit, career decision-making self-efficacy, outcome expectation, and major interest is required to encourage students in the field of the natural sciences to pursue career preparation behaviors related to their majors.

• Korean Journal of Microbiology
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• v.55 no.1
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• pp.33-38
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• 2019

Ochratoxin A (OTA), one of mycotoxins produced mainly by Aspergillus is a common contaminant of stored grains, posing health hazards to human and livestock. The aim of this study is to explore ability of isolated bacteria Bacillus subtilis AF13 and Streptomyces shenzhenensis YR226 to remove OTA. AF13 and YR226 could remove 94.23 and 97.73% of OTA ($100{\mu}g/L$), respectively during 24 h incubation in NB medium. When cultures of two strains were separated into washed cells and cell-free supernatant, the supernatant of both strains removed more than 90% of $100{\mu}g/L$ OTA, and 98.88% of OTA could be also removed by the washed cells of YR226. OTA removal occurred in a few second by the supernatant of both strains, and treatments of autoclaving, proteinase K and chymotrypsin did not affect the OTA removal by the culture supernatants, which indicate that some thermostable and non-proteinaceous substances secreted by these bacteria may be involved in OTA removal in these two bacteria. These results suggest that AF13 and YR226 can be used to remove OTA from OTA-contaminated grains and feeds, and therefore decrease economic damage in agriculture and feed industry.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.614-620
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• 2018

A rice bran physically treated to increase the residual gamma amino butyric acid (GABA) content (200 mg/100 g) or its hot-water extract (200 mg/100 g) was added into a white pan bread, and changes in the physical properties including color, and volume and texture changes during storage at room temperature were examined. The addition of bran powders had negative effects on bread quality and storage stability whereas that of rice bran extract (RBE) improved the storage stability of bread. The lightness of bread crumbs decreased but the volume of bread slightly increased after addition of the RBE. The increase in crumb hardness during storage was retarded by the RBE addition. The residual concentration of GABA in bread was increased 38-fold when 20% of RBE was added. The addition of RBE to white pan bread improved the resistance to staling and health-promoting function because of GABA.

• Journal of the Korea Institute of Construction Safety
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• v.2 no.1
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• pp.28-35
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• 2019

The average number of deaths in the construction industry reaches 500 per year, and in particular, it is confirmed that the type of accidents and deaths caused by disasters such as work platforms has occupied more than 60% of the total. In this study, we presented a structured and combined solution for technology, management, education, and cost that can solve systematically, politically, and external environmental factors as well as direct influence factors. In addition, we examined the safety and safety standards of domestic and international safety, and discussed implications. First, direct impact factors, organizational impact factors, policy influence factors, and external environmental impact factors were examined and classified into technical, education, and institutional dimensions. Second, in relation to the installation of the work scaffold, the standards (OSHA 1926.452), UK (The Work at Height Regulations 2005 No.735, BS5975), Japan (Labor Safety and Sanitation Regulations) and Germany (DIN 4420_4, DIN EN12810). In the case of domestic safety standards, similar to the foreign safety standards, safety measures such as materials and specifications are applied. However, details related to the installation, assembly and structure of the work platform are somewhat different from those in the United States and the United Kingdom excluding Japan. Using the results of this study, it is possible to understand the cause of the accident of foot pedestrian accident more systematically and comprehensively, and safety managers and researchers are expected to help in the accident investigation.

• Korean Journal of Heritage: History & Science
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• v.52 no.2
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• pp.106-121
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• 2019

Sustainable development in society has become the center of focus in many fields such as industry, environment, health, culture, etc. Considering that the concept of heritage involves understanding it as a 'resource' to improve the quality of people's lives, sustainability is an important goal that heritage policy has to achieve. Adopting the definition of sustainability in the 1987 Brundtland Report, this paper defines the concept of sustainability with respect to heritage, as well as their respective roles. Following that, three action principles are presented: value-based conservation, rational decision-making, and community involvement. Two cases demonstrating how the three principles should be practiced in managing change are then illustrated. Considering that heritage can play its role as a resource once its significance is protected, this paper argues that value-based rational decision-making is of paramount importance and the first principle. Conservation aims to manage change by practicing a cyclic process of value identification, value sustaining, and value dissemination. Therefore, this paper argues that all processes should be connected in the context of heritage values. A rational decision-making process practicing value-based conservation is then suggested. This paper argues that rational decision-making can only be practiced once values are identified by objective criteria and managed by rational judgment upon impact assessment. Community involvement, the third principle, is necessary to realize value-based conservation and rational decision-making. Recognizing that a community is a beneficiary of heritage and a creator of a beneficial process at the same time, it discusses the role of community and the importance of this role in policies for the sustainability of heritage. This paper concludes with a set of recommendations to improve policies after examining the two decision-making cases.

• Korean Journal of Microbiology
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• v.55 no.3
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• pp.226-233
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• 2019

Ochratoxin A (OTA) that is one of mycotoxins produced mainly by Aspergillus spp. is a common contaminant of stored grains and poses health hazards to human and livestock. The aim of this study is to explore the ability of isolated bacteria Bacillus subtilis AF13 and Streptomyces shenzhenensis YR226 to inhibit growth and OTA production of 3 ochratoxigenic Aspergillus strains. The antifungal activity against mycelial growth and sporulation of Aspergillus strains was examined by coculture with AF13 and YR226 on potato dextrose agar plate. AF13 and YR226 reduced 77.58 and 78.48% of fungal colony radius, respectively, and both strains inhibited fungal sporulation up to 99% in 10 days of incubation. YR226 also reduced more than 91% of spore germination of 3 fungal strains. When Aspergillus strains were cocultured with AF13 or YR226 in yeast extract sucrose medium, mycelial growth and OTA production decreased in all three fungal strains. In particular, AF13 completely inhibited the mycelial growth of A. alutaceus and inhibited its OTA production by 99%, and YR226 also reduced mycelial growth and toxin production up to 99%, respectively. Antimicrobial substances produced by AF13 and YR226 included siderophore, chitinase, protease, ${\beta}$-1,3-glucanase and biosurfactant. These results suggest that AF13 and YR226 can be used in a biological method to prevent valuable crops against mycotoxigenic fungi, and therefore decrease economic damage in agriculture and feed industry.

• Food Science and Industry
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• v.52 no.3
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• pp.261-271
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• 2019

Gut microbiome have recently provided evidence that the gut microbiota are capable of greatly influencing all aspects of physiology and immunology. Although a number of recent studies have shown that probiotics can modulate gut microbiota structure, the mechanism underlying this effect remains to be elucidated. In a disease state, the relative abundances of beneficial gut bacteria are generally reduced, which is restored by constant probiotic supplementation. Oral administration of probiotics improved the disease state by (1) inducing differentiation and function of regulatory T cells, (2) reducing inflammatory response, (3) modulating the gut environment, and (4) increasing the proportions of short-chain fatty acid- or beneficial metabolite-producing gut microbiota including the genera Bifidobacterium, Faecalibacterium, Akkermansia, etc. In this review, current knowledge on how probiotics can influence host's health by altering gut microbiota structure and on how probiotics and beneficial gut bacteria can be applied as next-generation probiotics will be discussed.

• The Korean Journal of Food And Nutrition
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• v.31 no.6
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• pp.811-820
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• 2018

This study suggests a method of making cheese using soybeans for healthy food for people that are allergic to animal proteins, vegetarians, people on a diet, infants and toddlers. Additionally, the study was conducted to provide basic data that can contribute to the development of a quality control class of Korean cheese and underdeveloped cheese industry. Soybean cheeses have a high protein content and low fat. The free amino acids of soybean cheeses contained 11.48 mg of arginine per 100 g, 9.33 mg of glutamate, and leucine 4.91 mg, in that order. The free amino acids of Company A's milk cheese contained 20.95 mg of glutamate, 8.95 mg of proline and 8.02 mg of lysine per 100 g. In soybean cheeses, there were 2.21 mg of tryptophan and 0.73 mg of cysteine, which were not analyzed in the milk cheese of company A. The contents of the constituent amino acids was 1,070.22 mg of glutamate, 467.30 mg of aspartate and 446.30 mg of leucine in 100 grams of soybean cheeses per 100 grams. The milk cheese of Company A was 1,715.97 mg of glutamate, 798.72 mg of leucine and 685.31 mg of proline. The mineral contents of the soybean cheese were 120.29 mg/100 g of calcium, 0.92 mg/100 g of iron, 0.78 mg/100 g of zinc and 0.40 mg/100 g of selenium, respectively. The contents of vitamin $B_1$ and ${\beta}$-glucan in soybean cheese were higher than that of the milk cheese in Company A at 0.08 mg/100 g and 13.73 mg/g, respectively. Therefore, it is considered that the soy cheese is excellent in nutritional aspect and will contribute to health promotion. It is also suitable for people that are allergic to animal proteins, vegetarians, people on a diet and healthy foods for infants.