• Korean Journal of Plant Resources
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• v.36 no.1
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• pp.32-61
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• 2023

To investigate the distribution of vascular plants growing at Wetland in Daegu·Gyeongbook, we surveyed from June 2020 to October in 2021. The flora of wetland was classified as a total of 459 taxa comprising of 104 families, 286 genus, 406 species, 12 subspecies, 34 varieties, 6 forma, 1 hybrid. Among them, the rare plants species 5 taxa, endemic plants 11 taxa, floristic regional indicator plants 57 taxa, naturalized plants 27 taxa and wetland plants 74 taxa were recorded. The percentage of urbanization index was 8.44%, the naturalized ratio was 5.88%, respectively.

• Korean Journal of Social Welfare Studies
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• v.42 no.1
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• pp.117-149
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• 2011

This study examined the relationship between discrimination experienced by children of multicultural families and their psychological distress. As new minorities growing up with bicultural identities in Korean society, children from multicultural families are often exposed to racial discrimination and such experience often acts as a stressor in their everyday life. In order to examine the effect of discrimination on their psychological distress as well as the role of social support, a survey was conducted in 25 elementary schools in Daejeon city and Chungnam and Chungbuk province. Results indicated that children's experiences of discrimination significantly affected their psychological distress level that the more they were exposed to discrimination, the higher levels of depression and anxiety they experienced. Among social support domains, only peer support was found to be significantly related to both the experience of discrimination and their depression and anxiety levels. Supporting the social support deterioration model, the findings showed that more experiences of discrimination led to reduced peer support which in turn, increased the likelihood of being depressed and anxious. Peer support was also significant in partially mediating the discrimination-psychological distress relationship. Implications for social work practice with children from multicultural families are provided.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.697-702
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• 2023

Recently, with the introduction of drones, a core technology of the 4th industrial revolution, various convergence education using drones is being conducted in school education sites. In particular, drone theory and practice education is being conducted in connection with free semester classes and career exploration. The drone convergence education program has higher learner satisfaction than simple demonstration and practice education, and the learning effect is high due to direct practical experience. However, since practical education is being conducted for a large number of learners, it is impossible to restrict and control the flight of a large number of drones in a limited place. In this paper, we propose a monitoring system that allows the instructor to monitor multiple drones in real time and learners to recognize collisions between drones in advance when multiple drones are operated, focusing on education operated in schools. The communication module used in the experiment was equipped with GPS in Murata LoRa, and the server and client were configured to enable monitoring based on the location data received in real time. The performance of the proposed system was evaluated in an open space, and it was confirmed that the communication signal was good up to a distance of about 120m. In other words, it was confirmed that 25 educational drones can be controlled within a range of 240m and the instructor can monitor them.

• Nuclear Engineering and Technology
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• v.27 no.6
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• pp.877-887
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• 1995

YGN 3 is the first nuclear power plant to use the Core Protection Calculator (CPC) as the core protection system and the Core Operating Limit Supervisory System (COLSS) as the core monitor-ing system in Korea. The CPC is designed to provide on-line calculations of Departure from Nucleate Boiling Ratio (DNBR) and Local Power Density (LPD) and to initiate reactor trip if the core conditions exceed the DNBR or LPD design limit. The COLSS is designed to assist the operator in implementing the Limiting Conditions for Operation (LCOs) in Technical Specifications for DNBR/Linear Heat Rate (LHR) margin, azimuthal tilt, and axial shape index and to provide alarm when the LCOs are reached. During YGN 3 initial startup testing, extensive CPC/COLSS related tests ore peformed to ver-ify the CPC/COLSS performance and to obtain optimum CPC/COLSS calibration constants at var, -ious core conditions. Most of test results met their specific acceptance criteria. In the case of missing the acceptance criteria, the test results ore analyzed, evaluated, and justified. Through the analysis and evaluation of each of the CPC/COLSS related test results, it can be concluded that the CPC/COLSS are successfully Implemented as designed at YGN 3.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.252-257
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• 2023

In this study, to replace phthalate-based plasticizers known as endocrine disruptors, compounds as plasticizer candidates were synthesized by using alcohols containing rings and fatty acids extracted from animal and vegetable oils, and their properties as plasticizers, including their plasticization efficiency, were evaluated. Nine compounds synthesized by esterification of fatty acids (caprylic acid, capric acid, lauric acid) and alcohols (solketal, benzyl alcohol, cyclohexanol) were identified by ¹H-NMR. The nine synthetic compounds were evaluated for their plasticity by adding them to PVC resin, and compared with the commercial plasticizers DEHP, DINCH, and ESO. According to the results, plasticization efficiency was 0.96 to 1.02 times higher than DEHP, 0.94 to 0.98 times higher than ESO, and 1.05 to 1.10 times higher than DINCH. Thermal stability was somewhat lower than that of DEHP and DINCH, but showed better results than ESO. The results of the solvent extraction test showed that both aqueous and oily solvents showed higher values than DEHP and DINCH but showed similar or superior properties to ESO.

• Korea Trade Review
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• v.43 no.1
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• pp.199-221
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• 2018

The internationalization of venture firms is of importance resulting from the increased opportunities as well as the entry barriers faced in this process. This study is to investigate barrier factors affecting Korean venture firms' internationalization. Among these factors, we measured relative weights using Analytic Hierarchy Process (AHP). Literatures regarding global firm's internationalization was reviewed, and barriers were classified environment, corporate and CEO barriers. Multiple variables were used in order to measure their relative significance. We surveyed executives of venture firms comprising two groups: first, 15 global venture firms, and secondly, gradually internationalizing firms. The two groups show contradictory results as environment barriers are the primary for born-global ventures and corporate barriers are the primary for gradually internationalizing ventures. Concerning corporate barriers, the lack of marketing capability is the highest barrier for both groups. The CEO barrier is the lowest for both groups. Regarding corporate barriers, gradually internationalizing ventures considers the risk of business as highest, whereas born-global ventures features the lack of R&D capacity as highest Results of this paper imply that firms should consider priority and sequential approaches in facing environment, corporate and CEO barriers.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.2
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• pp.153-160
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• 2023

In this study, nano-sized C-S-H crystals were synthesized using the liquid phase reaction method and their properties were investigated. The synthesized C-S-H crystals were added to the cement composite in suspension form to determine their effect on the hydration properties of the cement. The amount of chemical admixture was varied to obtain nano-sized C-S-H crystals with optimal agglomerated morphology, and SEM photographs were analyzed. A cleaning process was added to remove harmful substances other than the synthesiz ed C-S-H crystals. It was found that the concentration of harmful substances was reduced in the case of C-S-H crystals subjected to the cleaning process. The synthesized C-S-H suspensions were prepared with and without the cleaning process, and cement composites were prepared with the cement weight content as the main variable. The effect of C-S-H crystals on the initial hydration properties of the cement was confirmed by microhydration heat analysis. In addition, mortar specimens were prepared to measure the compressive strength over time. The test results showed that the nano-sized C-S-H crystals act as nucleation sites in the cement paste to promote the early hydration of the cement and increase the early compressive strength.

• 한국체육학회지인문사회과학편
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• v.57 no.5
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• pp.1-11
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• 2018

The purpose of this study was to investigate the views of Joseon held by Kano Jigoro, who was the creator of judo and spread the martial arts ideology across the world, to shed light on the fundamental essence of the martial arts ideology spread around Korea. Conducted in this perspective, the study generated the following results: first, Kano Jigoro grew up, receiving history education from classical scholars of Japan. He was accordingly influenced by the Seikanron, which argues that Empress Jingu, a mythical character, conquered Silla, Baekje and Gaya. The Seikanron became the basis of the Imna Ilbonbu theory during the Japanese rule and was projected onto martial arts ideas Jeongryeokseonyong and Jatagongyeong that were completed by Kano Jigoro and introduced into Joseon. Secondly, Kano Jigoro distributed and expanded the tale of statehood in the prism of martial arts ideology since the Meiji Restoration, which was possible because he connected his martial arts ideas to the statehood of Japan. As a result, they were used as the logic of Korea and Japan are One in Joseon unlike the rest of the world where they were applied as peace ideas. Finally, his martial arts ideology introduced into Joseon during the Japanese rule went through acculturation and showed the contradiction of being interpreted differently according to different individuals. Most Japanese people made use of his martial arts as a means of the Korea and Japan are One policy, whereas the pioneers of the Korean people excluded Kano Jigoro's view of state, included the nationalistic features in it, and trained their martial arts as a means of overcoming the national crisis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3A
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• pp.555-563
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• 2006

Recently, many bridges become not only functionally obsolete of bridge deck due to inadequate width but also structurally deficient of substructure due to erosion. In these cases, widening is almost always more economical than complete replacement, and therefore there is a need to make available the results of research and field experience pertaining to the widening of bridge substructure. But, an experimental study for the guarantee of unification between existing and new substructure with adhesive anchor is so insufficient that the development of adhesive anchor system for the unification should be settled promptly. The purpose of the present study is to explore pull out and shear characteristics of adhesive anchor system. For this purpose, several series of concrete specimens have been tested. Major test variables were the bonded length, anchor diameter and anchor slope. The pull out strength, bond stress and shear strength of adhesive faces were measured for the specimens. The present study indicates that the pull out strength increased with more bonded length and more anchor diameter, and that the bond stress decreased with more bonded length and more anchor diameter. The pull out strength and the bond stress increases with more anchor slope and it is considered that the slope of $5^{\circ}$ was more efficient. From the shear tests, it is supposed that anchor diameters more than D19 was proper to the adhesive anchor. Finally, it is expected that both experimental data in these tests and further study including mock-up tests will contribute to the establishment of the unification between existing and new substructure with adhesive anchor.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.4A
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• pp.537-548
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• 2008

Recently, the prestressed unbonded concrete structures are increasingly being built. The mechanical behavior of prestressed concrete beams with unbonded tendon is different from that of normal bonded PSC beams in that the increment of tendon stress was derived by whole member behavior. The purpose of the present paper is therefore to evaluate the flexural behavior and to propose the equation of ultimate tendon stress by performing static flexural test according to span/depth, concrete compression strength, reinforcement ratio and the effect of existing bonded tendon. From experimental results, for cracking, yielding and ultimate load, the effect of reinforcement ratio was more effective than concrete compression strength, and the beams having high strength concrete had a good performance than having low concrete, but there was no difference between high strength and low strength. And as L/dp was larger, test beams had a long region of ductility. This means that unbonded tendon has a large contribution after reinforcement yielding. Especially, the equation of ACI-318 was not match with test results and had no correlations. After analysis of test results, the equation of ultimate unbonded tendon stress without slip was proposed, and the proposed equation was well matched with test results. So the proposed equation in this paper will be a effective basis for the evaluation of unbonded tendons without slip, analysis and design.