• Journal of Korean Society of Transportation
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• v.30 no.1
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• pp.135-147
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• 2012

The benefit of traffic information on variable message sign can be divided into two. At the public level, the benefit of ATIS is the travel time saving, which is not only induced from ATIS, but also mixed with that of ATMS. In the economic appraisal of ITS, the benefit of ATIS has so far been regarded as the derived benefit from ATMS. At the user level, the benefit of ATIS is reduced driver uncertainty through the forward traffic status information. User can benefit from the information on VMS and therefore may have the willingness to pay for it. Recently attempt to qualify the value of information on VMS was increased, but there was a danger of distorting or over-estimates of the ATIS benefit because the related studies didn't consider the time-dependent attributes of traffic information and provided the single value. Estimates of the time-varying value should be needed for a rigorous economic appraisal of ATIS. In this study, we varied the value of information on VMS according to peak and non peak trip and verified the hypothesis that time-varying of value was statistically significant.

• Journal of Life Science
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• v.30 no.3
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• pp.278-284
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• 2020

Magnolia kobus is known to exert various biological effects, such as antioxidant and hypnotic activity. In this study, we investigated the antimicrobial and anti-inflammatory activity of M. kobus essential oil extracted using steam distillation. Its antimicrobial activity was tested against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa by the paper disk diffusion and minimum inhibitory concentration (MIC) methods. Its anti-inflammatory activity was evaluated by measuring its inhibition ratio on the production of nitric oxide (NO) and PGE₂ in lipopolysaccharide (LPS)-induced RAW264.7 cells. Its composition was analyzed by gas chromatography-mass spectrometry (GC-MS). The results showed that M. kobus essential oil exhibited excellent antibacterial activity against S. aureus, with a clear zone of 18 mm and an MIC value of 0.25 mg/ml. Its clear zones against P. aeruginosa and E. coli were 14 mm and 17 mm, respectively, while its MIC values were 1 mg/ml and 0.5 mg/ml, respectively. The essential oil exhibited no cytotoxicity to the RAW264.7 cells at a concentration of 500 ㎍/ml while showing NO (37.7%) and PGE₂ inhibition (24.0%). Its three main fragrance ingredients identified were 3-carene (77.07%), β-elemene (6.92%), and caryphyllene (2.86%). The results suggest that M. kobus essential oil has potential as a cosmetic functional material with antimicrobial and anti-inflammatory effects.

• Communications for Statistical Applications and Methods
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• v.15 no.5
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• pp.697-708
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• 2008

Operational risk is defined as the risk of loss resulting from inadequate or failed internal processes, people and systems, or external events. The advanced measurement approach proposed by Basel committee uses loss distribution approach(LDA) which quantifies operational loss based on bank's own historical data and measurement system. LDA involves two distribution fittings(frequency and severity) and then generates aggregate loss distribution by employing mathematical convolution. An objective validation for the operational risk measurement is essential because the operational risk measurement allows flexibility and subjective judgement to calculate regulatory capital. However, the methodology to verify the soundness of the operational risk measurement was not fully developed because the internal operational loss data had been extremely sparse and the modeling of extreme tail was very difficult. In this paper, we propose a methodology for the validation of operational risk measurement based on bootstrap confidence intervals of operational VaR(value at risk). We derived two methods to generate confidence intervals of operational VaR.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.186-192
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• 2010

Streptococcus mutans, one of the major causal agents of dental caries, is component of the dental plaque. It produces various organic acids such as lactic acid which is the end-product of glycolysis, and this leads to dental caries. A new system using species-specific monoclonal antibodies was developed to detect Streptococcus mutans in saliva. The system quickly detects salivary Streptococcus mutans in 30min and classifies the result into two levels. The purpose of this study was to investigate correlation between monoclonal antibody-based detecting system and selective medium-based detecting methods. Children's deft indices were also compared with Streptococcus mutans counts in MSB agar plate. Subjects consisted of 15 children in the age of 3 to 6 years. They were assigned to three groups : Group I(deft index = 3), Group II(deft index $\leqq$3), Group III(deft index $\geqq$4). The results are as follows : 1. The rate of children with positive response was 13.3% and with negative response was 86.7% in the result of Saliva-checkTM Mutans test kit. 2. There was a positive correlation between monoclonal antibody-based detecting system and selective medium-based detecting methods(p<0.05). 3. Streptococcus mutans counts in MSB agar plate were irrelevant to deft of children(p=0.34).

• Clinical and Experimental Pediatrics
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• v.46 no.12
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• pp.1207-1211
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• 2003

Purpose : This study was performed to observe the relationship of plasma L-arginine level and the severity of disease and pulmonary artery pressure in respiratory distress syndrome of premature infants. Methods : Peripheral blood samples were obtained at 1st, 3rd and 7th day from 21 premature infants with respiratory distress syndrome to analyze the L-arginine concentration. Oxygenation index (OI), an indicator of the severity of the disease, was calculated at the same time of the blood sampling. And pulmonary artery pressure was measured by Doppler echocardiography at each period. Plasma L-arginine level, OI and right ventricular systolic time interval(RVSTI) were analyzed. Results : Plasma L-arginine concentration of the 1st day was lower than 3rd and 7th day. OI and RVSTI were significantly correlated with each other(r=0.772, P<0.01). Plasma L- arginine level was correlated with oxygenation index(r=-0.346, P<0.01) and RVSTI(r=-0.416, P<0.01). Conclusion : Plasma L-arginine level was lowest in the 1st day during the study period. Plasma L-arginine concentration correlated significantly with the severity of respiratory distress syndrome and pulmonary artery pressure in premature infants.

• Korean Journal of Food Science and Technology
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• v.43 no.4
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• pp.469-474
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• 2011

Ginger (Zingiber officinale Rosc.) is a well known edible plant that is traditionally used to treat various illnesses related to inflammation and oxidative stress. Steam distillated ginger oil or water extract are mainly used for related products; however, it is unclear whether these fractions contain most of the bioactive compounds or the highest efficacy. This investigated the antioxidant effects of extracts prepared by supercritical fluid extraction (SFE). 6-Gingerol was the most abundant component in hexane fraction of ethanol extract from ginger. The antioxidative properties of SFE oil and Marc ethanol fractions were demonstrated using the 2,20-diphenylpicrylhydrazyl (DPPH) and 2,2'-azinobis 3-ethyl benzothiazoline-6-sulfonic acid (ABTS) radicals scavenging assays. A clear correlation was observed between total polyphenol contents and $RC_{50}$ values in the Marc ethanol fraction. These results indicate that not only SFE oil but the marc after SFE could be good sources for the food industry.

• Polymer(Korea)
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• v.33 no.1
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• pp.26-32
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• 2009

The aim of this research was to prepare microparticulate systems based on poly (lactide-co-glycolide)(PLGA) for the local release of ipriflavone in order to reduce bone loss. We developed the IP loaded PLGA microspheres using relatively simple oil-in-water(O/W) solvent evaporation method. HPLC was used to perform the in vitro release test of IP and morphology of cell attached on the micro-spheres was investigated using SEM. Cytotoxicity was assayed by cell counting kit-8 (CCK-8) test. Osteogenic differential cells were analyzed by ALP activity. Through RT-PCR analysis, we observed osteocalcin, ALP, and Type I collagen mRNA expression. The release of IP in vitro was more prolonged over 42 days and IP/PLGA microspheres showed the improvement on the cell proliferation, ALP activity and RT-PCR comparing with control (only PLGA). This initial research will be used to direct future work involved in developing this composite injectable bone tissue engineering system.

• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.43-52
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• 2022

Recently, the government has been expanding the supply of hydrogen vehicles according to the roadmap for vitalizing the hydrogen economy, but is developing safety assessment and inspection technology for the relevant vehicles. This study analyzed the prevention of hydrogen bus accidents' economic effect that arises from the application and development of large-capacity CHSS oil pressure repetition-test assessment technology, hydrogen bus internal chamber pressure transmission and emission volume inspection technology, among various technologies capable of assessing the safety of a hydrogen bus fuel system. To this end, the contingent valuation method (CVM), one of the value evaluation methods of non-market goods, was applied to investigate users' willingness to pay for each inspection technology. The survey for users' willingness to pay was conducted by attaching posters to promote surveys on the internet and within buses to the entire public. As a result of the analysis, the average WTP of the hydrogen bus internal chamber pressure transmission volume inspection technology was 25.3 KRW, the average WTP of the hydrogen bus internal chamber pressure emission volume inspection technology was 18.6 KRW, and the average WTP of the large-capacity CHSS oil pressure repetition-test assessment technology was measured at 16.7 KRW. In addition, the costs and benefits of the introduction of the relevant inspection technology were defined through the interviewing of experts at related research institutions and businesses. As a result of conducting an economic analysis (4.5% discount rate) according to the development of each inspection technology, economic feasibility was seen in all assessment and inspection technologies. As much as the technology is indispensable for the safe use of hydrogen buses, it shows that investment in related technology is very necessary in the future. However, because it was decided that the relevant analysis will differ according to the distribution rate of hydrogen buses, further analysis following this future distribution rate of hydrogen buses is needed, and future users should be made clearly aware of the safety and environmental nature of the technology.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.70-77
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• 2013

BACKGROUND: Nitroxoline is an antibiotic agent. It is used for the treatment of the second bacterial infection by the colibacillosis, salmonellosis and viral disease of the poultry. When the nitroxoline is indiscreetly used, the problem about the abuse of the antibiotics can occur. Therefore, this study presented the residue analytical method of nitroxoline in food for the safety management of animal farming products. METHODS AND RESULTS: A simple, sensitive and specific method for nitroxoline in chicken muscle by high performance liquid chromatograph with PDA was developed. Sample extraction with acetonitrile, purification with SPE cartridge (MCX) were applied, then quantitation by HPLC with C18 column under the gradient condition with 0.1 % tetrabutylammonium hydroxide-phosphoric acid and methanol was performed. Standard calibration curve presented linearity with the correlation coefficient ($r^2$) > 0.999, analysed from 0.02 to 0.5 mg/L concentration. Limit of quantitation in chicken muscle showed 0.02 mg/kg, and average recoveries ranged from 72.9 to 88.1 % in chicken muscle. The repeatability of measurements expressed as coefficient of variation (CV %) was less than 12 % in 0.02 and 0.04 mg/kg. CONCLUSION(S): Newly developed method for nitroxoline in chicken muscle was applicable to food inspection with the acceptable level of sensitivity, repeatability and reproducibility.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.285-292
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• 2013

This study was carried out to validate the safety of ametoctradin residues in agricultural commodities by developing an official analysis method. An analytical method was developed and validated using HPLC-PDA detectors. The samples were extracted with methanol, subsequently partitioned with dichloromethane and purified with florisil column chromatograph using acetone/hexane (30/70, v/v) as solvent. The method was validated by using grape, hulled rice, mandarin, and potato spiked with ametoctradin at 0.05 and 5.0 mg/kg, and pepper at 0.05 and 2.0 mg/kg. Average recoveries were 76-114.8% with relative standard deviation less than 10%, and the limit of detection and limit of quantification were 0.0125 and 0.05 mg/kg, respectively. The result of recoveries and overall coefficient of variation of the laboratory results from Gwangju regional Food and Drug Administration (FDA) and Daejeon regional FDA was accorded with Codex Alimentarius Commission Guideline (CAC/GL 40). Based on these results, this method was found to be appropriate for ametoctradin residue determination and can be used as the official method of analysis.