• Restorative Dentistry and Endodontics
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• v.36 no.1
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• pp.59-65
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• 2011

Objectives: The purpose of this study is to compare the apical transportation and working length change in curved root canals created in resin blocks, using 3 geometrically different types of Ni-Ti files, K3, NRT, and Profile. Materials and Methods: The curvature of 30 resin blocks was measured by Schneider technique and each groups of Ni-Ti files were allocated with 10 resin blocks at random. The canals were shaped with Ni-Ti files by Crown-down technique. It was analyzed by Double radiograph superimposition method (Backman CA 1992), and for the accuracy and consistency, specially designed jig, digital X-ray, and CAD/CAM software for measurement of apical transportation were used. The amount of apical transportation was measured at 0, 1, 3, 5 mm from 'apical foramen - 0.5 mm' area, and the alteration of the working length before and after canal shaping was also measured. For statistics, Kruskal-Wallis One Way Analysis was used. Results: There was no significant difference between the groups in the amount of working length change and apical transportation at 0, 1, and 3 mm area (p = 0.027), however, the amount of apical transportation at 5 mm area showed significant difference between K3 and Profile system (p = 0.924). Conclusions: As a result of this study, the 3 geometrically different Ni-Ti files showed no significant difference in apical transportation and working length change and maintained the original root canal shape.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.2
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• pp.139-147
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• 1991

The preservative effect of cellophane film packing on the quality of semi-salted and dried mackerel was studied. The product(P) of semi-salted and dried mackerel was prepared from raw mackerel by filleting, cleaning, soaking in 15%9v/w) salt solution for 30min, draining, packing with cellophane film (PT# 300, thickness:$20{\mu}{\textrm}{m}$) and drying for 4 hrs at $40^{\circ}C$ in hot air dryer. The product (C) was also prepared without cellophane film packing after draining. The product (C) and (P) were stored at $5.0{\pm}0.5^{\circ}C$. After processing and during storage, moisture content of product (P) was higher than that of product (C), but contents of VBN(volatile basic nitrogen), amino nitrogen and TMA of product (P) on dry basis were lower than those of product (C). Viable cell count, TBA value, peroxide value and decreasing rate of polyenoic acid of product (P) were also lower than those of product (C). In sensory evaluation, the shelf life of product (C) was about 9 days and that of product (P) was about 14 days. From the results of chemical and sensory evaluation, it was concluded that cellophane film packing was a good condition for preserving the quality of semi-salted and dried mackerel.

• Journal of agriculture & life science
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• v.46 no.3
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• pp.37-45
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• 2012

To select bacterial strains with antifungal activity against an anthracnose fungal disease causing damage severely on hot pepper, previous isolates obtained from plant root samples were screened. Among 457 isolates, IA70-5 isolate was finally selected and identified as Streptomyces padanus based on 16S rDNA sequence analysis. Strain IA70-5 is non-pigmenteous, non-mobile, and filamentous. S. padanus IA70-5 inhibited effectively the mycelium growth, spore germination, and appressorium formation of Colletotrichum acutatum in vitro. The results of this study demonstrated that IA70-5 strain, especially applied on fruit of hot pepper, decreased disease incidence 90% for pre-inoculation before pathogen treatment. Taken together, S. padanus IA70-5 strain is a promising biological control agent to control of a major fungal pepper disease, anthracnose.

• Korean Journal of Comparative Education
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• v.24 no.3
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• pp.227-244
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• 2014

This study is to explore and compare the main research area of national and international universities, figure out the differences of the research trends depending on national and international universities, and suggest which area Korea universities could focus on and head to. The study is conducted on the fields of 'Communication and Media' in humanities and 'Electrical Engineering' in engineering for the cases of 10 national and international universities. The data is based on the 3 years journals published between 2009 and 2011 by 10 universities, and analyzed using network analysis. The data is processed with three steps and visualized using Ucinet, Gephi, Netdraw program. These result show, in case of 'Communication and Media', the focus of the universities in Korea mainly on the classical research fields with only a few new research area comparing with international universities. In case of 'Electrical Engineering', national and international universities covers various areas, from classic ones to emerging ones. But the specific research areas are different. These results suggest the research areas which ares the universities in Korea will pursue in near future.

• Journal of Convergence for Information Technology
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• v.8 no.3
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• pp.79-84
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• 2018

Cloud services are readily available through a variety of media, attracting a lot of attention from users. However, there are various security damages that abuse the privacy of users who use cloud services, so there is not enough technology to prevent them. In this paper, we propose a protection model to safeguard user's privacy in a cloud environment so as not to illegally exploit user's privacy. The proposed model randomly manages the user's signature to strengthen the role of the middle manager and the cloud server. In the proposed model, the user's privacy information is provided illegally by the cloud server to the user through the security function and the user signature. Also, the signature of the user can be safely used by bundling the random number of the multiplication group and the one-way hash function into the hash chain to protect the user's privacy. As a result of the performance evaluation, the proposed model achieved an average improvement of data processing time of 24.5% compared to the existing model and the efficiency of the proposed model was improved by 13.7% than the existing model because the user's privacy information was group managed.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.4
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• pp.401-411
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• 2015

This study was performed to investigate the wound healing effect of skin regeneration cosmetics utilizing low molecular weight Polydeoxynucleotide (PDRN). High purity PDRN was prepared from salmon testes poly-deoxy-ribonucleotide through protein and toxin removal process and molecular weight reduction. In order to evaluate the wound healing effect of PDRN in SD rats, 4 sites of dorsal skin of each animal were excised by using biopsy punch and $500{\mu}L$ of test solution was topically applied once daily for 4 weeks. The tissue changes were observed for every week during the application periods. After applying the PDRN to the wound, the skin was cut flower and contraction of the wounds more quickly, and the coating of PDRN in the wound area was reduced significantly as compared to the positive control group $Fucidin^{(R)}$ applied. The microscopic observation of stained tissue showed that a positive control was most rapid in re-epithelialization ability followed by the PH group, PDRN group, HA group. In addition, transforming growth factor ($TGF-{\beta}$) and vascular endothelial growth factor (VEGF), such as in the growth factor was similar to the results of staining of tissue lesions. In conclusion, it is determined that the low molecular weight PDRN has the therapeutic effect to the wound, and could be used as a functional material of cosmetics and medical industries.

• Food Science and Preservation
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• v.18 no.6
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• pp.923-929
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• 2011

For the purpose of investigating the in vitro antidiabetic activity of a medicinal herb mixture prepared through traditional antidiabetic prescription, the study analyzed the existence of insulin-similar components and examined ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibition activity. As a result of arranging the medicinal herb mixture extracts over the 3T3-L1 fibroblast in the concentration of $10{\mu}g/mL$, which confirmed that it included much of insulin sensitizer components as 151.7% in the differentiation of 3T3-L1 fibroblast. The inhibition activity against ${\alpha}$-amylase of the medicinal herb mixture extracts as hypoglycemic agent were 38.4, 31.5 and 16.6% in the concentration of 10.0, 1.0 and 0.1 mg/mL, respectively. The inhibition activity against ${\alpha}$-glucosidase of the medicinal herb mixture extracts were 81.3, 35.8 and 26.7% in the concentration of 10.0, 1.0 and 0.1 mg/mL, respectively. The inhibition activity against ${\alpha}$-glucosidase in the ethyl acetate fractions of the water and 80% ethanol extracts were 66.9% and 55.1%, respectively, the highest levels in the various solvent extracts.

• Food Science and Preservation
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• v.25 no.1
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• pp.98-106
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• 2018

Portulaca oleracea L., a species of Portulacaceae, is ubiquitous. It is a well-known traditional Chinese medicine for removing heat, counteracting toxicity, cooling blood, and maintaining hemostasia; it is also used as antidysentery agent. This study investigated the anti-oxidative and anti-inflammatory activities of water and ethanol extracts from P. oleracea. The total polyphenol content ($21.08{\pm}0.03mg\;GAE/g$) and total flavonoid content ($5.45{\pm}0.76mg\;QE/g$) of the ethanolic extracts were higher than those of the water extracts. The antioxidative activities were determined by evaluating the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical scavenging activity and by the ferric reducing antioxidant potential (FRAP) assay. The ABTS radical scavenging activity of the water extract (75.53%) was higher in those of the water extract (67.03%) at concentration of $1,000{\mu}g/mL$. The DPPH radical scavenging activity and FRAP of the ethanol extract were higher than those of the water extract. We also investigated the anti-inflammatory activity of the P. oleracea extracts in LPS-stimulated Raw 264.7 cells. The production levels of nitric oxide (NO) and reactive oxygen species (ROS) significantly decreased with an increasing concentration of the extract. The expression levels of pro-inflammatory cytokines (tumor necrosis faction (TNF)-${\alpha}$, interleukin (IL)-$1{\beta}$, and IL-6) were significantly lower in the ethanol extract than in the LPS alone treatment group. Based on these results, ethanolic extract from P. oleracea could be an effective antioxidant and anti-inflammatory agent.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1300-1305
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• 2011

The study was conducted to investigate the characteristics of flower quality and yield of gerbera 'Sunny Lemon' by mutrient solution strength and media of nutrient solution. The plant growth of 'Sunny Lemon' showed the highest values in the media of rockwool and perlite 1: peatmoss 2. Especially the yield of cut flowers for a year was more than 60 flowers and the flower longevity was over 10 days irrespective of nutrient solution concentration in the two media. There were no significant differences of plant characteristics in the nutrient concentration of 1/2 and 1 times, and the mineral nutrient contents showed similar values. Therefore, we recommended the media of perlite1: peatmoss2 with the concentration of 1/2 times for economical use. The rockwool media was not appropriate because of the weak buffer capacity like EC and pH.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1052-1062
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• 2011

Residual of heavy metals originated from abandoned metal mines in agricultural field can cause adverse effect on ecosystem and eventually on human health. For this reason, remediation of heavy metal contaminated agriculture field is a critical issue. In this study, five different amendments, agriculture lime, dolomite, steel slag, zeolite, and compost, were evaluated for stabilization efficiency of heavy metals in agricultural field. Applied mixing ratio of amendments was varied (2% or 6%) depending on properties of amendments. Result showed that soil pH was increased compared to control (6.1-6.7) after mixing with amendments and ordered as dolomite (7.2~8.3) > steel slag (6.7~8.1) > agriculture lime (6.6~7.4) > zeolite (6.2~6.9) > compost (6.1~7.1). Among other amendments, agriculture lime, steel slag, and dolomite showed the highest stabilization efficiency of heavy metals in soil. For Cd, stabilization efficiency was 49~72%, 51~83%, and 0~36% for agriculture lime, steel slag, and dolomite respectively. In case of Pb, 43~64, 37~73%, and 51~73% of stabilization efficiency was observed for agriculture lime, steel slag, and dolomite respectively. However, minimal effect of heavy metal stabilization was observed for zeolite and compost. Based on result of this study, amendments that can increase the soil pH were the most efficient to stabilize heavy metal residuals and can be adapted for remediation purpose in agricultural field.