• Journal of Radiation Protection and Research
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• v.40 no.2
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• pp.118-123
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• 2015

The frequency of diagnostic radiation examinations in medical institutions has recently increased to 220 million cases in 2011, and the annual exposure dose per capita was 1.4 mSv, 51% and 35% respectively, compared to those in 2007. The number of chest radiography was found to be 27.59% of them, the highest frequency of normal radiography. In this study, we developed a shielding device to minimize radiation exposure by shielding areas of the body which are unnecessary for image interpretation, during the chest radiography. And in order to verify its usefulness, we also measured the difference in entrance surface dose (ESD) and the absorbed dose, before and after using the device, by using an international standard pediatric (10 years) phantom and a glass dosimeter. In addition, we calculated the effective dose by using a Monte Carlo simulation-based program (PCXMC 2.0.1) and evaluated the reduction ratio indirectly by comparing lifetime attributable risk of cancer incidence (LAR). When using the protective device, the ESD decreased by 86.36% on average, nasal cavity $0.55{\mu}Sv$ (74.06%), thyroid $1.43{\mu}Sv$ (95.15%), oesophagus $6.35{\mu}Sv$ (78.42%) respectively, and the depth dose decreased by 72.30% on average, the cervical spine(upper spine) $1.23{\mu}Sv$ (89.73%), salivary gland $0.5{\mu}Sv$ (92.31%), oesophagus $3.85{\mu}Sv$ (59.39%), thyroid $2.02{\mu}Sv$ (73.53%), thoracic vertebrae(middle spine) $5.68{\mu}Sv$ (54.01%) respectively, so that we could verify the usefulness of the shielding mechanism. In addition, the effective dose decreased by 11.76% from $8.33{\mu}Sv$ to $7.35{\mu}Sv$ before and after wearing the device, and in LAR assessment, we found that thyroid cancer decreased to male 0.14 people (95.12%) and female 0.77 people (95.16%) per one million 10-year old children, and general cancers decreased to male 0.14 people (11.70%) and female 0.25 people (11.70%). Although diagnostic radiation examinations are necessary for healthcare such as the treatment of diseases, based on the ALARA concept, we should strive to optimize medical radiation by using this shielding device actively in the areas of the body unnecessary for the diagnosis.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.2
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• pp.253-261
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• 2004

Ginsenosides and green tea extracts show a variety of biomedical efficacies such as anti-aging, anti-oxidation and anti-tumor-promotion effects. (-)-Epigallocatechin-3-gallate (EGCG) has been reported to inhibit the UVB-induced apoptosis by increasing the Bcl-2-to-Bax ratio. We have previously shown that ginsenoside Fl protects human HaCaT cells from ultraviolet-B (UVB)-induced apoptosis by maintaining constant levels of Bcl-2 and Brn-3a. Here, we investigate the combined effect of ginsenoside Fl and EGCG on the protection of human HaCaT keratinocyte against UVB-induced apoptosis. When treated individually, although 5 ${\mu}$M ginsenoside Fl and 50${\mu}$M EGCG protected cells from UVB-induced apoptosis, 2${\mu}$M ginsenoside Fl or 10${\mu}$M EGCG treatment showed very little protection effect. However, cotreatement of 2${\mu}$M ginsenoside Fl and 10${\mu}$M EGCG successfully protected HaCaT cells from UVB-induced cell death. As expected, combining ginsenoside Fl and EGCG efficiently prevented UVB-induced decrease of Bcl-2 and Brn-3a expression. In addition, cotreatment with ginsenoside F1 and EGCG prevented the dephosphorylation of Rb, whereas individual treatment with ginsenoside Fl or EGCG failed to prevent the dephosphorylation of Rb even at high concentrations.

• Journal of Life Science
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• v.33 no.11
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• pp.923-935
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• 2023

Rubus crataegifolius (RC), Ulmus macrocarpa (UM), and Gardenia jasminoides (GJ) are well-known folk medicines in Asia used to treat various gastrointestinal disturbances. The present study evaluated the gastroprotective effect of LS-RUG-com, a mixture of commercially prepared powders of RC, UM, and GJ with a ratio of 3:1:2(w/w/w) against HCl/ethanol-induced gastritis, indomethacin-induced ulcers, and esophageal reflux-induced esophageal mucosal damage and Helicobacter pylori infections. In addition, TNF-α and IL-1β expressions were also determined and measured in esophageal tissue. As to HCl/ethanol-induced gastritis, the LS-RUG-com treatment at a dose of 150 mg/kg showed a remarkable anti-gastritis effect. Regarding indomethacin-induced gastric ulcers, the LS-RUG-com treatment had a significant anti-gastric ulcer effect. Furthermore, in the gastroesophageal reflux disease (GERD) model experiment, the LS-RUG-com treatment resulted in the histological recovery of stomach damage and mucosal injuries. Furthermore, the LS-RUG-com treatment led to an increase in gastric content pH, an increase in mucus protection, and a decrease in gastric pepsin output with a significant decrease in TNF-α and IL-1β. As to the Helicobacter pylori infected animal model, LS-RUG-com had a notable inhibitory effect on Helicobacter growth. The use of RC, UM, or GJ in isolation or the LS-RUG-com treatment as whole had good effects in terms of anti-oxidation, anti-neutralization, gastric acid secretion inhibition, and anti-lipid peroxidation, which supported the use of natural products as systemic gastric protective agents. Our results suggest that the LS-RUG-com might be a significant systemic gastroprotective agent that could be utilized for the treatment and/or protection from gastric disturbances and related damage.

• Journal of the Korea Society of Computer and Information
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• v.18 no.4
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• pp.35-43
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• 2013

As texture images have become prevalent throughout a variety of industrial applications, copyright protection of these images has become important issues. For this reason, this paper proposes a color-texture image watermarking algorithm utilizing texture properties inherent in the image. The proposed algorithm selects suitable blocks to embed a watermark using the energy and homogeneity properties of the grey level co-occurrence matrices as inputs for the fuzzy c-means clustering algorithm. To embed the watermark, we first perform a discrete wavelet transform (DWT) on the selected blocks and choose one of DWT subbands. Then, we embed the watermark into discrete cosine transformed blocks with a gain factor. In this study, we also explore the effects of the DWT subbands and gain factors with respect to the imperceptibility and robustness against various watermarking attacks. Experimental results show that the proposed algorithm achieves higher peak signal-to-noise ratio values (47.66 dB to 48.04 dB) and lower M-SVD values (8.84 to 15.6) when we embedded a watermark into the HH band with a gain factor of 42, which means the proposed algorithm is good enough in terms of imperceptibility. In addition, the proposed algorithm guarantees robustness against various image processing attacks, such as noise addition, filtering, cropping, and JPEG compression yielding higher normalized correlation values (0.7193 to 1).

• Journal of Digital Convergence
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• v.11 no.12
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• pp.649-656
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• 2013

This study was conducted to find out about the implementation status of dental treatment infection control standards of dental hygienists. The subjects of research were the dental hygienists working at dentist offices in Chungnam, Cheonan-si using self-input method from July 25th, 2012 to August 1st 2012. The collected data was analyzed after computerized statistical processing using SPSS 18.0. For hepatitis B vaccination, the results were high with 75.0% of answers being 'yes' or auto-active immunity, but for the latest hepatitis vaccination period showed highest results in '5 years or more ago' with 48.0%. Although 93.0% answered that vaccination was important, the percentage of replies that they had vaccination education was relatively low with 41.0%. For the use of personal protection tools the use of protective goggles was low compared to the use of masks and medical gloves. The percentage of subjects that answered that they always wash their hands before treatment was relatively low with 56.0% compared to 82.0% of subjects that answered that they always washed their hands after treatment. Dental treatment equipment washing before sterilization, use of packing and re-sterilization of tools with damaged packing showed high results for 'yes', but the ratio of subjects that answered 'no' to water line management was low with 39%.

• Korean Journal of Environment and Ecology
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• v.20 no.3
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• pp.331-339
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• 2006

Inhabitant patterns of the legally protected species and the characteristics of fish fauna in the Pyeongchang River, Korea, were studied from April to July 2004 by selecting 6 sites. The number of fish samples in this period were 2,448 in 35 species of 9 families. A total of nineteen endemic species (54.29%) were presented and those were Hemibarbus mylodon and Acheilognathus signifer. The highest frequency was shown in Zacco korean us (34.84%) and Pungtungia herzi (10.25%) and Coreoleuciscus splendidus (6.86%) were the next. In addition, The highest biomass was found in Z. koreanus (5,580.2g) and Coreoperca. herzi (1.241.2g) and C. splendidus (1,207.0g) were the next. When comparing the distribution of the legally protected species in within the Han River system, the highesting distributions were determined in the Pyeongchang and Dong River (6 species). The ratio of individuals in the Pyeongchang River was shown to be higher (10.62%) than that of other lakes and streams. In conclusion, more precise protection and protective plans were needed in order to maintain the lake ecology in good status because the Pyeongchang River is relatively well protected from the anthropogenic disturbance in the legally protected species including the endemic species.

• Korean Journal of Environment and Ecology
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• v.24 no.4
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• pp.363-394
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• 2010

This study was carried out to investigate the vascular flora of the Hongcheon-gun area in Gangwon Province. The vascular plants were collected 13 times(from April 2008 to May 2009), and 1,055 taxa in total were identified, including 43 orders, 118 families, 443 genera, 903 species, 6 subspecies, 125 varieties, 18 form and 3 hybrids. Among them, 37 taxa of Korean endemic plants and the Office of Forestry-designated rare & endangered plants were identified as 35 taxa. Based on the list of plants which have been approved for overseas delivery, 61 taxa were recorded in the investigated area. The Ministry of Environment-designated plants, which should be protected by the wildlife protection law, were identified as four taxa and 224 taxa of specially designated plants by the Ministry of Environment. The naturalized plants were identified as 45 taxa, and their naturalization ratio and urban index were found to be 4.3%, and 16.1% respectively. 1,055 taxa listed consists of 359 taxa(34%) of edible plants, 293 taxa(27.7%) of medicinal plants, 166 taxa(15.7%) of pasture plants, 143 taxa(13.5%) of ornamental plants, 41 taxa(3.9%) of timber plants, 25 taxa(2.3%) of fiber plants and 3 taxa(0.2%) of industrial plants.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.4
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• pp.75-81
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• 2012

In case of crushing rock to produce materials for lean concrete subbase layer in concrete pavement, natural sand is used for the gradation adjustment of aggregates, and the percentage of natural sand used is 30%~40% of the weight ratio of aggregate mix. The supply of natural sand that is used in lean concrete as a fine aggregate is getting harder due to the current of exhaustion of source, and the cost for the purchase of natural sand is included in the cost of roadway construction. This study, therefore, was conducted in order to resolve the exhaustion of materials and economize in construction expenditure by the application of screenings, which is by-product of crushing rock in quarry, as an alternative to natural sand. As a result of a comparative analysis on the application of screenings and natural sand with typical types of rock that is produced in domestic, which was conducted in the first year, It is found out that the use of screenings as a fine aggregate showed better unconfined compression strength. Verification of actual application of screenings was conducted in the second year, after test construction and follow-up investigation. The compressive strength, compaction density, settlement of screenings applied case was higher than that of natural sand. Thus, it is expected that application of screenings to construction in field will contribute to the cost saving, material recycling and the protection of environment.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.5
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• pp.601-608
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• 2014

In this paper, we have characterized the electrical properties related to gate leakage current in AlGaN/GaN MISHFETs with varying the thickness (0 to 10 nm) of $Al_2O_3$ gate insulator which also serves as a surface protection layer during high-temperature RTP. The sheet resistance of the unprotected TLM pattern after RTP was rapidly increased to $1323{\Omega}/{\square}$ from the value of $400{\Omega}/{\square}$ of the as-grown sample due to thermal damage during high temperature RTP. On the other hand, the sheet resistances of the TLM pattern protected with thin $Al_2O_3$ layer (when its thickness is larger than 5 nm) were slightly decreased after high-temperature RTP since the deposited $Al_2O_3$ layer effectively neutralizes the acceptor-like states on the surface of AlGaN layer which in turn increases the 2DEG density. AlGaN/GaN MISHFET with 8 nm-thick $Al_2O_3$ gate insulator exhibited extremely low gate leakage current of $10^{-9}A/mm$, which led to superior device performances such as a very low subthreshold swing (SS) of 80 mV/dec and high $I_{on}/I_{off}$ ratio of ${\sim}10^{10}$. The PF emission and FN tunneling models were used to characterize the gate leakage currents of the devices. The device with 5 nm-thick $Al_2O_3$ layer exhibited both PF emission and FN tunneling at relatively lower gate voltages compared to that with 8 nm-thick $Al_2O_3$ layer due to thinner $Al_2O_3$ layer, as expected. The device with 10 nm-thick $Al_2O_3$ layer, however, showed very high gate leakage current of $5.5{\times}10^{-4}A/mm$ due to poly-crystallization of the $Al_2O_3$ layer during the high-temperature RTP, which led to very poor performances.

• Journal of Wetlands Research
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• v.22 no.1
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• pp.31-38
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• 2020

Weirs are to secure amount water of streams and drop structures are to enhance stabilization of stream bed and bridges are to connect isolated region, which are called stream crossing structures. In the stream design criteria, directions for minimum size of structures are suggested to secure stability of stream crossing structures. However the sizes of almost all existing weirs and drop structures are not satisfied with the stream design criteria and only 22 percent of the peirs of bridges are satisfied. To enhance hydraulic stability of existing weirs and drop structures, it is required that the ratio of bed protection to apron should be above 3.3. According to factual survey of structures in the sample streams, it has been shown that the longitudinal slope of rapid works with 1:20 is the most reasonable to design velocity if existing weirs and drop structures are rehabilitated into rapid works. It has been known that violating freeboard and span length of piers should make existing bridges reconstructed or removed. However, comprehensive review including deterioration level of bridges, special regulation for span length, etc. should be considered to determine rehabilitation plan of bridges. In this study, a procedure has been suggested to improve hydraulic stability of weirs, drop structures and piers of bridges. Sound environment of stream and reduction of natural disaster could be achieved by improving stability of cross structures, which could be obtained by governmental budget and active stream management including observance of design criteria.