• Journal of Korean Society on Water Environment
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• v.36 no.2
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• pp.116-124
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• 2020

This study aims to identify the characteristics of organic matter and pollutant sources using water quality and stable isotope ratios (δ¹⁵N, δ¹³C) of the two inflow tributaries (Gulpo (GP) and Anyang (AY) streams). Water samples were analyzed in June and September 2018, and the results showed that the concentrations of nutrients, such as TN and NO₃-N, were increased at GP4, which is located at the downstream of sewage treatment facilities(STFs). TOC and TN ratios showed a strong positive correlation (R² = 0.77, p<0.01) at all points except for GP4. The results of GP's stable isotope ratio analysis do not appear to be a constant cluster compared to AY because GPs with large amounts of pollutants from the industry (metal processing companies, etc.) have less tributary, shorter waterway and significantly different external sources. This could be attributed to different sources of external inflow despite its smaller number of tributaries and shorter waterways than AY. In the first half of the year, the δ¹⁵5N of GP4 was affected by discharge of STFs, while AY3 seemed to have an influence of tributary than the discharge of STFs. Consequently, using water quality, stable isotope ratio and C/N, the sources of contamination in two streams with different contaminants were identified and origin was estimated.

• Science of Emotion and Sensibility
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• v.5 no.1
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• pp.25-32
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• 2002

This paper aimed to identify the sensation and the sensibility of transformed colors from the rustling sound of silk fabrics and to visualize the relationship between sensibilities and fabrics by two-dimensional model. The rustling sounds of 7 silk fabrics were recorded and then the recorded sounds were transformed into colors by the program of sound to color transformation. The sensation and the sensibility of transformed colors were evaluated by 30 participants with Likert scale and the physical properties of each specimen were obtained with red portion (RP), green portion (GP), blue portion (BP), and sum of color count (CC) by means of new equation. The adjectives of sensibility were grouped into three groups: Elegant, Active, and Tough. Elegant was related with RP positively and CC negatively. On the other hand, Active was related with GP and CC positively. Also Tough was highly related with RP. Furthermore, the fabrics that were estimated the high purchase preference showed high CC, RP and GP. Also two dimensional model of relation of the sensation and the sensibility could help to understand those relation.

• Applied Chemistry for Engineering
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• v.25 no.6
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• pp.581-585
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• 2014

We conducted investigation on the hybridization of poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT : PSS) with graphene derivative (G-PSS), which has been prepared by wrapping reduced graphene oxide (RGO) with PSS. In situ polymerization of PEDOT/PSS in the presence of G-PSS afforded the PEDOT/PSS and graphene hybrid (GP). The analysis of XPS, IR and Raman spectroscopies for GP showed that PEDOT/PSS was successfully synthesized and hybridized with graphene. Compared to the G-PSS, GP showed an enhanced electrical conductivity of $4.46{\times}10^2S/m$ with a good wter-dispersity.

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.522-530
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• 2022

In this study we aimed to develop novel ZnO-NP/chitosan/β-glycerophosphate (ZnO-NP/CS/β-GP) antibacterial hydrogels for biomedical applications. According to the mass fraction ratio of ZnO-NPs to chitosan, mixtures of 1, 3, and 5% ZnO-NPs/CS/β-GP were prepared. Using the test-tube inversion method, scanning electron microscopy and Fourier-transform infrared spectroscopy, the influence of ZnO-NPs on gelation time, chemical composition, and cross-sectional microstructures were evaluated. Adding ZnO-NPs significantly improved the hydrogel's antibacterial activity as determined by bacteriostatic zone and colony counting. The hydrogel's bacteriostatic mechanism was investigated using live/dead fluorescent staining and scanning electron microscopy. In addition, crystal violet staining and MTT assay demonstrated that ZnO-NPs/CS/β-GP exhibited good antibacterial activity in inhibiting the formation of biofilms and eradicating existing biofilms. CCK-8 and live/dead cell staining methods revealed that the cell viability of gingival fibroblasts (L929) cocultured with hydrogel in each group was above 90% after 24, 48, and 72 h. These results suggest that ZnO-NPs improve the temperature sensitivity and bacteriostatic performance of chitosan/β-glycerophosphate (CS/β-GP), which could be injected into the periodontal pocket in solution form and quickly transformed into hydrogel adhesion on the gingiva, allowing for a straightforward and convenient procedure. In conclusion, ZnO-NP/CS/β-GP thermosensitive hydrogels could be expected to be utilized as adjuvant drugs for clinical prevention and treatment of peri-implant inflammation.

• Food Science and Preservation
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• v.24 no.5
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• pp.576-584
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• 2017

With the goal of developing a new functional fermentation milk using green tea powder (GP), milk was fermented with direct vat set (DVS) starter culture containing Streptococcus salivarius subsp. thermophilus, Lactobacillus paracasei and L. delbrueckii subsp. bulgaricus. We investigated fermentation characteristics and antioxidative activities of fermented milk supplemented with different concentrations (0.5, 1, 2, 3%) of GP. All samples were evaluated for pH, total acidity, viable cell count, and sugar contents. The pH of all samples decreased during fermentation, and the final pH ranged from 4.35 to 4.51. The acidity increased during fermentation, after the fermentation was completed, the titratable acidity was 0.8 to 1.1%. And viable cell count of all samples increased during fermentation, and the final viable cell count was 8.57 to 8.89 log CFU/mL. The sugar content decreased as the fermentation proceeded and finally reached 12 to $13^{\circ}Brix$. And increasing GP, decreased brightness and increased yellowness. Increasing GP concentration added to milk, improved DPPH free radical scavenging activity and ferric ion reducing activity of fermentation milk. The fermentation milk kept their pH, total acidity and viable cell counts standard of fermentation milk during the storage period at $4^{\circ}C$. These findings confirmed the possibility of development of the novel functional fermentation milk through the investigation of the quality characteristics of the fermentation milk added with GP.

• Journal of Life Science
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• v.25 no.9
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• pp.1027-1035
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• 2015

A strain GP32 which produces a highly viscous extracellular polysaccharide was conducted with soil samples and identified as Pseudomonas species. The culture flask conditions for the production of extracellular polysaccharide by Pseudomonas sp. GP32 were investigated. The most suitable carbon and nitrogen source for extracellular polysaccharide production were galactose and (NH₄)₂SO₄. The optimum carbon/nitrogen ratio for the production of extracellular polysaccharide was around 50. The optimum pH and temperature for extracellular polysaccharide production was 7.5 and 32℃, respectively. In batch fermentation using a jar fermentor, the highest extracellular polysaccharide content (15.7 g/l) was obtained after 70 hr of cultivation. The extracellular polysaccharide produced by Pseudomonas sp. GP32 (designated Biopol32) was purified by ethanol precipitation, cetylpyridinium chloride (CPC) precipitation, and gel permeation chromatography. Biopol32, which has an estimated molecular weight of over 3×10⁷ datons, is a novel polysaccharide derived from sugar components consisting of galactose, glucose, gulcouronic acid and galactouronic acid in an approximate molar ratio of 1.85 : 3.24 : 1.00 : 1.42. The solution of Biopol32 showed non-Newtonian characteristics. The viscosity of Biopol32 exhibited appeared to be higher at all concentration compared to that of zooglan from Zoogloea ramigera. An analysis of the flocculating efficiency of Biopol32 in industry wastewater (food, textile, and paper wastewater) revealed chemical oxygen demand (COD) reduction rates 58.4-67.3% and suspended solid (SS) removal rates 82.6-91.3%. Based on these results, Biopol32 is a possible candidate for industrial applications such as wastewater treatment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.1031-1039
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• 2016

The Quasi-Zenith Satellite System(QZSS) is the Japanese satellite navigation system, which designs to increase the GPS system's visibility in the urban areas. The first satellite(Michibiki) was launched in 2010 and started to broadcast navigation signals. Therefore, the purpose of the research is to analyze the performance of GPS and QZSS based on the advantage of the integrated GNSS. Especially, the study has been processed in terms of improving satellite navigation parameters around Korean Peninsula. To do this, there have been the comprehensive analysis of the QZSS characteristics, the experimental test, and its statistical analysis for realizing advantage of GPS and QZSS. Through these systemic steps, it was recognized that the integrated GPS and QZSS has more reliable than GPS in case of not only limited visibility but also ordinary positioning. Additionally, the integrated GPS and QZSS would be very useful to improve the various navigation parameters around the peninsula.

• Journal of Pharmaceutical Investigation
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• v.35 no.4
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• pp.249-254
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• 2005

Multidrug resistance (MDR) of cancer cells is, at least in part, associated with the overexpression of P-glycoprotein (P-gp). Many studies have demonstrated that natural compounds obtained from fruits, vegetables, teas and medicinal plants may modulate P-gp activity. The objective of the present investigation was to examine the effect of seven natural compounds on the P-gp activity in human uterine sarcoma cell line, MES-SA/DX5. Daunomycin uptake was significantly increased by biochanin A and silymarin (p<0.0001) whereas it was reduced by morin (p<0.01). The efflux of daunomycin from the cells was significantly inhibited by biochanin A, morin, cephalotaxine, berberine (p<0.05) and silymarin (p<0.0001). Biochanin A, berberine and silymarin significantly decreased $IC_{50}$ value of daunomycin (p<0.05) while morin increased it (p<0.05). These results suggest that some natural compounds such as biochanin A and silymarin may inhibit P-gp function and can be developed as MDR reversing agents to improve the efficacy of chemotherapeutic drugs when administered concomitantly.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.3
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• pp.267-275
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• 2007

Nowadays, it grows bigger the importance of water resource management, and so, hydrographic surveying technology in river is important because it serves basic data about river environment. And, also, the application field of GPS has been increased and expected to be more increased because of the change of the geodetic reference system to World Geodetic System. In this study, hydrographic surveying in Hwang river in Geochang is accomplished by RTK GPS and Total Station and they are compared and analyzed the both results. The section profile in river is made by Hec-Ras program and CAD. The results show it can be saved 15.3% in surveying times and the amount of surveying works can be enlarged 42.5%. And the standard error between RTK results with calibration and the results without calibration turned out as 2.1 cm. So we have a conclusion that RTK GPS is more efficient surveying method than total station in hydrographic surveying in river.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.6
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• pp.659-667
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• 2009

In this study, an integrated GNSS Simulator called Inha GNSS Simulation System (IGSS) using 3D spatial information was developed and validated. Also positioning availability and accuracy improvement were evaluated under the integrated GNSS environment using IGSS. GPS and GLONASS satellite visibility predictions were compared with real observations, and their frequency of error were 6.4% and 7.5%, respectively. To evaluate positioning availability and accuracy improvement under the integrated GNSS environment, the Daejeon government complex area was selected to be the test site because the area has high-rise buildings and thus is susceptible to signal blockages. The test consists of three parts: the first is when only GPS was used; the second is when both GPS and GLONASS were simulated; and the last is when GPS, GLONASS, and Galileo were used all together. In each case, the number of visible satellites and Dilution Of Precision were calculated and compared.