• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.31-39
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• 2022

The purpose of this study was to investigate the whitening effects of hot water (AMPW) and ethanol (AMPE) extracts of Mangifera indica L. peel. To verify the whitening effects, tyrosinase inhibitory activity was measured. 9.51% inhibitory activity, and 35.98% inhibitory activity at 1,000 ㎍/ml. The effects of AMPW and AMPE on cell viability were measured using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in B16-F10 melanoma cells. Greater than 95% cell viability was observed at 100 ㎍/ml. Thus, subsequent experiments were performed at concentrations less than 100 ㎍/ml. The whitening effects were confirmed by measuring the protein and mRNA expression levels of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein 1 (TRP-1), and TRP-2, which are factors involved in melanin synthesis. Western blotting and reverse transcription-polymerase chain reaction results confirmed that 100 ㎍/ml AMPW and AMPE showed superior inhibitory effects than the control treatment (alpha-melanocyte stimulating hormone only). Therefore, Mangifera indica L. peel extract had a whitening effect, and thus, has potential as a natural material for use in cosmetics.

• Economic and Environmental Geology
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• v.53 no.1
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• pp.111-120
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• 2020

Remarkable scientific and technological achievements are mainly shown in the 'super-convergence' or 'convergence of convergence' among cross- disciplinary fields, and advanced countries are promoting the 'high-risk, high-return research' ecosystem. Google LLC is carrying out numerous new challenges in terms of a non-failure perspective. Innovative research by the US Defense Advanced Research Projects Agency (DARPA) has produced such breakthroughs as the Internet, GPS, semiconductors, the computer mouse, autonomous vehicles, and drones. China is pioneering a 'Moon Village' and planning the world's largest nuclear fusion energy and ultra-large particle accelerator project. Japan has also launched 'the moonshot technology development research system' to promote disruptive innovation. In Korea, the government is preparing a new research program to tackle the global scientific challenges. Therefore, it is necessary to determine the reasonable geoscientific challenges to be addressed and to conduct a preliminary study on these topics. For this purpose, it is necessary to conduct long-term creative research projects centered on young researchers, select outstanding principal investigators, extract innovative topics without prior research or reference, simplify research proposal procedures, innovate the selection solely based on key ideas, and evaluate results by collective intelligence in the form of conferences.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.1
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• pp.148-156
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• 2013

This paper suggests a multi-level and multi-output SMPS based on a shared digital logic controller through independently operating in each dedicated time periods. Although the shared architecture can be devised with small area and high efficiency, it has critical drawbacks that real-time control of each DPWM generators are impossible and its output voltage can be unstable. To solve these problems, a real-time current compensation scheme is proposed as a solution. A current consumption of the core block and entire block with four driver buffers was simulated about 4.9mA and 30mA at 10MHz switching frequency and 100MHz core operating frequency. Output voltage ripple was 11 mV at 3.3V output voltage. Over/undershoot voltage was 10mV/19.6mV at 3.3V output voltage. The noise performance was simulated at 800mA and 100KHz load regulation. Core circuit can be implemented small size in $700{\mu}m{\times}800{\mu}m$ area. For the verification of proposed circuit, the simulations were carried out with Dong-bu Hitek BCD $0.35{\mu}m$ technology.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4773-4779
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• 2012

In this paper we propose two types of reconfigurable 3-D beam steering antenna for intelligent or smart antenna system. Proposed antennas are composed of triangular(structure1.) or circuler(structure2.) loop structure and bended dipole antenna structure. This antenna can steer beam pattern of 6 direction at xy-plane state (0, 1, 2) and xz-plane state (3, 4, 5) by 4 switch motion with one antenna element. Antenna structure1. is symmetric equilibrium structures based on feeding point. There is no grounding point. As a result, designed antenna's gain is similar to dipole antenna. Also, As unbalanced structure by using CPWG in the form of a semicircular, structure2. is enhanced directivity. The operation frequency of antenna are 2.5 GHz(Structure1.) and 2.55 GHz(Structure2.), maximum gain is 1.04 ~ 2.06 dBi(Structure1. : Omni-directional beam), 1.6 ~ 4 dBi(structure2. : Directional beam). The overall HPBW is about over $160^{\circ}$ in the both of the xy-plane and xz-plane at structure1. and over $125^{\circ}$ at structure2.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.262-269
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• 2008

This research, to find the cultural identity of taekwondo, presents the historical origin of taekwondo in lights of Choi-centric theory, kwan-centric theory, karate inflow theory, and successive traditional martial arts theory. Then it investigates taekwondo's inner identity as a Korean traditional martial art according to presence, popularity, and independence, three factors of identity suggested by Tak, S. S.(2000).As a result, it reached these conclusions: First, taekwondo was formed after going through fusion of Hong Hi Choi, karate income in period of cultural severance during Japanese occupation, the first kwan leaders and Korean traditional martial arts, process of disorder and cultural reproduction. Second, taekwondo has essentially inherited and developed Korean barehanded martial arts' movements that lay stress on foot skills, and this distinguishes it from hand-skill-based Japan's karate and China's Wushu Furthermore, trunk/groin protectors and headgears are blended remarkably with taeguk patterns and traditional Colors of Five Directions. All terms rendered into pure Korean words shows the essence of Korean localization. It is therefore concluded that Koreans should, along with trying to overcome exclusive nationalism as a country of origin, build a new paradigm of establishing an identity as a global martial art sport.

• KSBB Journal
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• v.22 no.6
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• pp.371-377
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• 2007

Polyhydroxyalkanoates (PHAs) are a family of microbial polyesters that can be produced by fermentation from renewable resources. PHAs can be used as completely biodegradable plastics or elastomers. In this paper, novel applications of PHAs in biosensor are described. A general platform technology was developed by using the substrate binding domain (SBD) of PHA depolymerase as a fusion partner to immobilize proteins of interest on PHA surface. It could be shown that the proteins fused to the SBD of PHA depolymerase could be specifically immobilized onto PHA film, PHA microbead, and microcontact printed PHA surface. We review the results obtained for monitoring the specific interaction between the SBO and PHA by using enhanced green fluorescent protein, red fluorescent protein, single chain antibody against hepatitis B virus preS2 surface protein and severe acute respiratory syndrome coronavirus surface antigen as model proteins. Thus, this system can be efficiently used for studying protein-protein and possibly protein-biomolecule interactions for various biotechnological applications.

• Korean Journal of Veterinary Research
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• v.30 no.4
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• pp.355-360
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• 1990

Single nuclei from two-, four- and eight-cell mouse embryos were transplanted into enucleated two-cell embryos by micromanipulation and Sendai virus mediated fusion. The developmental potential of these reconstituted embryos in vitro and in vivo was examined. It was found that the single nuclei which were transplanted to enucleated two-cell embryos were not only able to develop to the blastocyst stage in vitro(two-cell nuclei, 76.5%; four-cell nuclei, 68.4%; eight-cell nuclei, 48.3%), but also able to develop to full term in vivo after transfer to recipient mice(two-cell nuclei, 37.1%; four-cell nuclei, 29.6%; eight-cell nuclei, 16.3%). Although the proportion of live young produced after transfer of nucler of nuclear transplant embryos which received eight-cell nuclei was significantly (p<0.05) reduced, it would be suggested that the overall efficiency in producing identical offspring is greater when eight-cell embryos were selected for nuclear donor than two- or four-cell embryos were selected.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.387-394
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• 2012

The study was conducted to develop an effective forest resources use models for an alternate use of abandoned quarry by an attitude survey. According to the result of survey, a pessimistic view due to dust, noise pollution, and forest damage was 5% higher than an affirmative view by economic benefits from the development of quarry. The 42% of the respondents preferred the alternate use of abandoned quarry and the 25% of the respondents wanted an art and cultural space. The optimum size of alternate use was 5-10 ha (43%) with the requirement of nearby residents (32%). According to the SWOT analysis for abandoned quarry, the strength factors were an effective use of land, the content development of modern industrial inheritance + cultural and art fusion, attraction for nearby city and visitors, a harmony of beauty landscape and clean environment, and a sustainable increase of domestic and foreign visitors with the 5-day-work week. The opportunity factors were the improvement of traffic networks through KTX and local highway, the creation of the new growth engines with the establishment of artistic creation belts, the providing of unique cultural and art space through grafting of tour and education, the creation of local income through stone processed goods, and the vitalization of local development through eco-city. The weakness factors were a psychological remoteness and backwardness, and the weakness of staying tour infra. The threat factors were a poor financial support for sustainable development in nearby quarry and a modify of legal and institutional system for the alternated use of abandoned quarry. The developed restoration models for the alternate use in abandoned quarry are classified to a sculpture park, a waterfall and lake park, a rock-climbing, a sports park + forest park, a native botanical garden, a culture and art park, a complex park, a water storage site, a water storage site to extinguish forest fire, a geriatric hospital, an agricultural facility, and a school site types etc. The results suggest that the alternate use in the abandoned soil and stone quarry is needed to establish facility use models with consideration of user's preference.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.461-468
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• 2017

This study measured and compared the protective clothing using Pb used for shielding in a diagnostic X-ray energy range, and the shielding rates of X-ray fusion shielding materials using Si and $TiO_2$. For the experiment, a pad type shielding with a thickness of 1 mm was prepared by mixing $Si-TiO_2$, and the X-ray shielding rate was compared with 0.5 mmPb plate of The shielding rate of shielding of 0.5 mmPb plate 95.92%, 85.26 % based on the case of no shielding under each 60 kVp, 100 kVp tube voltage condition. When the shielding of $Si-TiO_2$ pad was applied, the shielding rate equal to or greater than 0.5 mmPb plate was obtained at a thickness of 11 mm or more, and the shielding rate of 100% or more was confirmed at a thickness of 13 mm in 60 kVp condition. When the shielding of $Si-TiO_2$ pad was applied, the shielding rate equal to or greater than 0.5 mmPb plate was obtained at a thickness of 17 mm or more, and a shielding rate of 0.5 mmPb plate was observed at a thickness of 23 mm in 100 kVp condition. Through the results of this study, We could confirm the possibility of manufacturing radiation protective materials that does not contain lead hazard using various metalic compound and liquid Si. This study shows that possibility of liquid Si and other metalic compound can harmonize easily. Beside, It is flexible and strong to physical stress than Pb obtained radiation protective closthes. But additional studies are needed to increase the shielding rate and reduce the weight.

• Journal of Life Science
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• v.34 no.1
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• pp.18-27
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• 2024

Laying hens are known to be able to 'bio-accumulate' the health-promoting ingredients of their diet into eggs. The purpose of this study was to characterize lignan-rich eggs as functional food fed with Schisandra fruit by-product (SCP). Experimental diets were formulated using yellow corn, rice bran, soybean meal, fish meal, meat bone meal, poultry meal, vitamin premix, mineral premix, CaCO₃, and supplemented Schisandra chinensis by-product. This experiment conducted a completely randomized design with 5 treatments for 5 laying hens. Levels of SCP were fed control diet or each formulated diet containing 1%, 3%, 5% and 7% SCP powder. The weight of eggs and the lignan content in white and yolk of egg were investigated every 7 days. Egg production and egg weight were not affected by diet at less than 5% SCP in the diet, but were significantly reduced when the diet was supplemented with a high concentration of 7% SCP after 3 weeks. Yolks and white in eggs were analyzed by using a high performance liquid chromatography (HPLC) to determine the lignans profile. Higher dietary SCP supplementation significantly increased gomisin N and schisandrin C in Acetonitrile (p<0.05). Gomisin N in egg white increased in a concentration-dependent manner, but shisandrin C not detected. These results indicated that the use of SCP powder in layering diets was effective in egg quality and for the production of lignans fortified eggs. In conclusion, dietary supplementation of Schisandra by-product with less than 5% can produce lignans-enrich eggs used as functional foods.