• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.743-748
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• 2019

This study suggested a process of redesigning and implementing problem based learning to enhance students' active and collaborative learning activities and learning outcomes. The results of this study are as follows. First, the ef ect of class participation, academic self-regulated learning, and academic self-efficacy were examined. As a result, first, the average of learning activity, class extension, and participation in class was high in the difference between before and after class. Second, the post average scores of all the factors except the 'evaluation' were higher than before. Third, academic self-efficacy showed a significant difference only in 'task preference'. Finally, students' satisfaction with the class was also high. The professor was also able to grasp the characteristics of individual students by designing and operating the classes using PBL, and it was confirmed that the interaction with students increased. Based on the results of this study, we discussed the limitations and educational implications of the problem based learning class and propose successful problem based learning design and operation of the classroom.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.757-764
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• 2019

Depressurization occurs around underwater objects moving at high speeds. This causes cavitation nuclei to expand, resulting in cavitation. Cavitation is accompanied by an increase in noise and vibration at the site, particularly in the case of thrusters, and this has a detrimental ef ect on propulsion performance. Therefore, predicting cavitation is necessary. In this study, an analytical method for cavitation noise is developed and applied to an elliptic wing. First, computational fluid dynamics are performed to obtain information about the flow fields around the wing. Then, through the cavitation nuclei density function, number of cavitation nuclei is calculated using the initial radius of the nuclei and nuclei are randomly placed in the upstream with large pressure drop around the wing tip. Bubble dynamics are then applied to each nucleus using a Lagrangian approach for noise analysis and to determine cavitation behavior. Cavitation noise is identified as having the characteristics of broadband noise. Verification of analytical method is performed by comparing experimental results derived from the large cavitation tunnel at the Korea Research Institute of Ships & Ocean Engineering.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.336-345
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• 2020

Vessel Traf ic Services (VTS) is a system for ship safety and accident prevention. The International Maritime Organization (IMO), the International Association of Marine Aids to Navigation and the Lighthouse Authorities (IALA) established regulations related to VTS from an early stage. On December 3, 2019, South Korea enacted a special act called the "Act on Vessel Traffic Services (VTS Act)," which will take ef ect on June 4, 2020. In this paper, the background of this act's enactment is examined and its provisions are critically reviewed. In particular, the study intensively examines the reasons the immunity provisions for the VTS operator were removed and the current direction of improvements to the VTS Act is presented in terms of its feasibility. Most countries that do not have an Act related to VTS and its operator, refer to that of Korea. Therefore, it is necessary to reinforce the structures and definition of the VTS Act, as well as the immunity provisions for the VTS operator. The latter were removed during the National Assembly's legislation process, but were included in the initial bill, and should be reflected in subsequent revisions of the VTS Act.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.101-108
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• 2005

Children are in mixed dentition during 6 years after 3 years old. this time is very important for sound permanent dentition. There are many factors of influence to tooth eruption stage ; adjacent teeth, tooth resorption, early loss or retention of deciduous tooth, local lesion, lip and tongue, masticatory muscles, ect. These factors should be in balance, if not, relation of adjacent teeth is changed, then severe malocclusion is occurred maybe. These cases revealed influences of resin bonded metal splint on occlusal surface of children's molar to mixed dentition. Splints interfere with falling off of deciduous tooth, tooth eruption, normal occlusion formation, and development of mixed dentition and occlusion. Therefore we removed the metal splint from teeth, follow-up checked occlusion and tooth eruption.

• Journal of the Korean Electrochemical Society
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• v.12 no.4
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• pp.342-348
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• 2009

Zn/Air secondary batteries are high energy density type and environment-friendly. Also, they have safer properties than batteries of other type by low manufacturing cost and using the electrolyte solution. But, they have a weak concerning large output discharge. Oxygen evolution reaction(OER) and oxgen reduction reaction(ORR) in aqueous solution make a result of a decrease of cell efficiency and life span. Therefore, to minimize the voltage drop from between OCV and charge/discharge voltage is key point. The problem should be solved through developing catalysts of high efficiency. In this study, we synthesized $Pr_{1-x}(Sr,\;Ca)_x\;CoO_3$ powders by citric method and then measured physical characteristics of each powder by XRD, SEM, TGA etc. We examined its electrochemical properties by the cathodic polarization, anodic polarization and cyclic voltammogram. We achieved results that new catalysts showed better performances than existing $La_{1-x}Sr_xCoO_3$, $La_{1-x}Ca_xCoO_3$, ect. catalysts prepared in our lab.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.2
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• pp.184-190
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• 2008

Various ECT techniques have been applied basically to assess the integrity of steam generator tithing in nuclear power plant. Among these techniques, the bobbin probe technique is applied generally to examine the volumetric flaws such as a crack-like defect and wear which is generally occurred on steam generator tubing, and additionally MRPC probe is used to examine closely tile top of tubesheet and bending regions due to the high possibility of cracking. Dent and bulge also may be formed on tube during installation process and operation of steam generator, but the dent and bulge indications greater than specific size criteria are recorded on examination report because these indications are not considered as flaw. These indications can be easily detected with bobbin probe and approximately sized with profile bobbin probe, but the size and shape can not be accurately verified. Accordingly, in this study, the $8{\times}1$ multi-array EC probe was designed to increase the measurement accuracy of the sectional profiling EC testing of tube. As a result, we would like to propose the application of $8{\times}1$ multi-array EC probe for the measurement of size and shape of profile change on steam generator tube in OPR-1000 nuclear power plant.

• The Journal of Internal Korean Medicine
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• v.19 no.1
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• pp.57-72
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• 1998

This study has been carried out to investigate the effects of Ukgansan(UGS) extract on anti-convulsive, antipyretic, analgesic, sedative and GABAergic system of experimental animals. The results of this study were as follows : 1. UGS extract prolonged significantly the beginning time to convulsion and death induced by strychnine. 2. UGS extract prolonged significantly the time to death induced by electrical shock of ECT unit.(3 sec, 200 F, 25 mA) 3. On the experiment of hypothermic effects of UGS extract on the rectal temperature of mouse, UGS extract decreased significantly the rectal temperature of mouse 4. On the experiment of antipyretic effects of UGS extract on the febrile induced by the subcutaneous injection of $150\;{\mu}g/kg$ endotoxin in mouse, UGS extract decreased significantly the rectal temperature of mouse. 5. On the experiment of analgesic effects of UGS extract on the writhing syndrome induced by intraperitoneal injection 0.7% acetic acid 1 ml/100g in mouse, the writhing syndrome induced by acetic acid was reduced significantly by administration of UGS extract. 6. On the experiment of effects of UGS extract on spontaneous motor activity measured by wheel cage method in mice, the spontaneous motor activity was reduced significantly by administration of UGS extract. 7. On the experiment of effects of UGS extract on the activity of GABA-transaminase(GABA-T) in mouse brains after 21 days of oral administration of UGS extract. the activity of GABA-T was reduced significantly by administration of UGS extract. 8. On the experiment of effects of UGS extract on the activity concentration of GABA in mouse brain after 21 days of oral administration of UGS extract, the activity concentration of GABA was reduced significantly by administration of UGS extract. 9 On the experiment of effect of UGS water extract on the activity of GAD in mouse brain after 21 days of oral administration of UGS extract, the activity of GAD was reduced significantly by administration of UGS extract. According to the these results, Ukgansan extracts reveal the effects on the anti-convulsive, antipyretic, analgesic, sedative and GABAergic system.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.886-894
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• 2013

The National Standard Food Composition Table published by the Rural Development Administration (RDA) provides the foundations in research, nutrition monitoring, policy and dietary practices in Korea. This databases consists of several sets of data including food descriptions, nutrients, portion weights, and source of data. The National Standard Food Composition Table have been published since 1970 and, recently, new version (8th edition) of Food Composition Table which has quantitative and qualitative nutrient data is released in 2011. In addition, the User-friendly Food Composition Table is divided into adult, children, and elderly categories depending on the subjects because we need different nutrients according to various ages. The Tables of Food Functional Composition is firstly edited in 2009. RDA published the minerals and fatty acids composition table, tables of amino acid, fat-soluble vitamin composition table, and the cholesterol table. The resulting database will be widely used. The users of the databases are from diverse fields, includeing federal agencies, the food industry, health professionals, restaurants, software application developers, academia and research organizations, international organizations, and foreign governments ect. Therefore, consistent improvements of the database is important, so that people can better address such health challenges by providing reliable and accurate data.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.12
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• pp.461-494
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• 1999

This study is to analyse the applicability of governing law in multi-party contractual relationship of letter of credit. And this study is also to suggest the limits of the possibility of applicable law in multi-party contract. The contract of letter of credit constitutes complex relationship, i.e., applicant -beneficiary, applicant-issuing bank, issuing bank-intermediary bank ect. The law applicable to letter of credit should not use a singular governing law in all credit transaction as sales contract. To solve these problems, the author analysed the law applicable to the credit under multi-party contractual relationship as follow : (1) the principle of party autonomy (2) In the absence of express agreement with regard to the law applicable to the contract, lex loci contractus, lex loci solutionis, the law intended by the parties, the law with which contract is most closely connected. Accordingly, when attempting to ascertain the law governing the credit, it should be borne in mind that the credit involves several contractual relationships. I would like to conclude as follows: 1. The contract between the applicant and the Issuing bank is to be governed by the law of the country where the contract is made, and in which the bank carries on business and has issued the credit. 2. When it comes to the beneficiary-Intermediary bank relationship the following rule is given : The liability of an intermediary bank to the seller is governed by the law the country where the intermediary bank is operating if it is acting as principal. If, however, it is acting as agent(advising bank), it will be the law of the country where his principal is situate. 3. The contract between the beneficiary and the Issuing bank is governed by the law of the country where the payment is to be performed. 4. The contract between the Issuing bank and Intermediary bank is governed by 1) the law of the issuing bank is applicable if the intermediary bank only advises the credit, 2) the law of the issuing bank is applicable but if the intermediary bank makes payment, accepts or negotiates drafts against the tender of the documents, i.e., act as the bank dffecting the payment., 3) the law of the confirming bank is applicable if the irrevocable letter of credit is confirmed by the intermediary bank

• 보존과학연구
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• s.37
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• pp.27-41
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• 2016

This study surveyed color awareness and color systems according to pedigree(Ilseob, Woljoo, Hyegak, Manbong ect.) targeting Dancheongjang (craftsman) who has inherited Dancheong (traditional multicolor). From the survey of color awareness, standardized color system of 'traditional color' awareness by Dancheongjang is 'the color inherited by the master' and it was identified that there is the standardized color system in awareness and its standard is either same or similar to traditional Dancheong. Also, according to each period, colors of Dancheong have been changed, it was thought that change in color materials and preference had went with times. From eleven main colors of Dancheong, chromaticity materials which were preferred by Dancheongjang were analyzed by the faction of Dancheongjang and colors and it resulted in a variety of color ranges over all. In the case of Yangnok, Noerok, Juhong it showed a high deviation with a wide color range while there was a low deviation with a narrow color range in Hayeop, Daja, Seokganju. Through this study it was difficult to identify clear correlations and tendencies of color system by the faction of Dancheongjangs. This is judged to be a reflection of the subjective artistry of the members.