• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1610-1616
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• 2016

This study aimed to establish an optimal extraction process and high performance liquid chromatography-ultraviolet (HPLC-UV) analytical method for determination of 3,5-dicaffeoylquinic acid (3,5-DCQA) as a part of materials standardization for the development of a xanthine oxidase inhibitor as a health functional food. The quantitative determination method of 3,5-DCQA as a marker compound was optimized by HPLC analysis using a Luna RP-18 column, and the correlation coefficient for the calibration curve showed good linearity of more than 0.9999 using a gradient eluent of water (1% acetic acid) and methanol as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 320 nm. The HPLC-UV method was applied successfully to quantification of the marker compound (3,5-DCQA) in Aster glehni extracts after validation of the method with linearity, accuracy, and precision. Ethanolic extracts of A. glehni (AGEs) were evaluated by reflux extraction at 70 and $80^{\circ}C$ with 30, 50, 70, and 80% ethanol for 3, 4, 5, and 6 h, respectively. Among AGEs, 70% AGE at $70^{\circ}C$ showed the highest content of 3,5-DCQA of $52.59{\pm}3.45mg/100g$ A. glehni. Furthermore, AGEs were analyzed for their inhibitory activities on uric acid production by the xanthine/xanthine oxidase system. The 70% AGE at $70^{\circ}C$ showed the most potent inhibitory activity with $IC_{50}$ values of $77.01{\pm}3.13{\sim}89.96{\pm}3.08{\mu}g/mL$. The results suggest that standardization of 3,5-DCQA in AGEs using HPLC-UV analysis would be an acceptable method for the development of health functional foods.

• Journal of Gastric Cancer
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• v.8 no.4
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• pp.189-197
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• 2008

Purpose: Peritoneal lavage cytology is regarded as a useful diagnostic test for detecting intraperitoneal micrometastsis. However, there are currently no reports about cytological examination with $ThinPrep^{(R)}$ (CY), a newly introduced fluid-based diagnostic system, in patients with advanced gastric cancer (AGC). This study was performed to analyze the clinical significance of intraoperative peritoneal lavage for CY in AGC patients. Materials and Methods: 424 AGC patients were suspected to have serosal exposure macroscopically during surgery and they underwent intraoperative peritoneal lavage for CY between 2001 and 2006 at Korea Cancer Center Hospital. The clinical data, pathological data and CY results were collected and analyzed retrospectively. Results: The percentage of cytology positive results was 31.1%, and this was well correlated with the T-stage, N-stage and P-stage. The 3-year survival rates of CY0 and CY1 were 68.1% and 25.9%, respectively. According to the P-stage and CY, the 3-year survival rates were 71.1% in P0CY0, 38.9% in P0CY1, 38.5% in P1/2/3CY0 and 11.0% in P1/2/3CY1. Interestingly, both the P0CY1 and P1/2/3CY0 survival curves were similar figures, but they were significantly different from those of the other groups. Multivariate analysis indicated that CY was an independent, strong prognostic factor for survival, as well as sex, the T-stage, N-stage, P-stage, other metastasis and the serum CEA. CY1 was revealed as a risk factor for peritoneal recurrence in the curative resection group. Conclusion: The results certify indirectly that cytological examination using $ThinPrep^{(R)}$ is a very reliable diagnostic method for detecting intraperitoneal micrometastasis from the fact that it is not only a strong prognostic factor, but it is also a risk factor for peritoneal recurrence in AGC patients. Therefore intraoperative peritoneal lavage should be included in the routine intraoperative staging workup for AGC, and its result will provide a good target for the treatment of peritoneal micrometastasis.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.1
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• pp.51-57
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• 2009

Biofouling in seawater reverse osmosis (SWRO) desalination process causes many problems such as flux decline, biodegradation of membrane, increased cleaning time, and increased energy consumption and operational cost. Therefore biofouling is considered as the most critical problem in system operation. To control biofouling in early stage, detection of the most problematic bacteria causing biofouling is required. In this study, six model bacteria were chosen; Bacillus sp., Flavobacterium sp., Mycobacterium sp., Pseudomonas aeruginosa, Pseudomonas fluorescens, and Rhodobacter sp. based on report in the literature and phylogenetic analysis of seawater intake and fouled RO membrane. The adhesion to RO membrane, the high pressure resistance, and the hydrophobicity of the six model bacteria were examined to find out their fouling potential. Rhodobacter sp. and Mycobacterium sp. were found to attach very well to RO membrane surface compared to others used in this study. The test of hydrophobicity revealed that the bacteria which have high hydrophobicity or similar contact angle with RO membrane ($63^{\circ}$ of contact angle) easily attached to RO membrane surface. P. aeruginosa which is highly hydrophilic ($23.07^{\circ}$ of contact angle) showed the least adhesion characteristic among six model bacteria. After applying a pressure of 800 psi to the sample, Rhodobacter sp. was found to show the highest reduction rate; with 59-73% of the cells removed from the membrane under pressure. P. fluorescens on the other hand analyzed as the most pressure resistant bacteria among six model bacteria. The difference between reduction rates using direct counting and plate counting indicates that the viability of each model bacteria was affected significantly from the high pressure. Most cells subjected to high pressure were unable to form colonies even thought they maintained their structural integrity.

• Journal of Life Science
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• v.26 no.2
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• pp.190-197
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• 2016

Aflatoxin M₁ can be produced in cow’s milk when cows eat contaminated produce. Milk is a major source of food for infants and for children who have a weak level of immunity, and the detection of Aflatoxin M₁ for risk assessment is necessary in order to reduce the amount of it in milk. In this study, the Aflatoxin M₁ level was monitored for one year in raw milk samples obtained from Chungnam Province, Korea. The milk samples were divided into three categories: 1. milk samples from a standard general farm, 2. milk samples from a HACCP controlled farm, and 3. milk samples from the supply of Aflatoxin M₁ reduced fodder. The average concentrations of Aflatoxin M₁ in milk were 0.023±0.005 ug/l for the standard general farm, 0.017±0.004 ug/l for the HACCP controlled farm, and 0.013±0.003 ug/l for the supply of Aflatoxin M₁ reduction fodder. Milk collected from the supply of Aflatoxin M₁ reduction fodder had the lowest level of Aflatoxin M₁. However, when efficiency and economic aspects are considered the most effective way of reducting Aflatoxin M₁, could be taking milk from the HACCP controlled farm and implementing good feed management. Institutional support from the government, careful management of dairy farming, and a strict farm sanitation program are required in order to lower the level of Aflatoxin M₁ in milk.

• Journal of Korean Society of Transportation
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• v.17 no.1
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• pp.29-39
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• 1999

An earlier study of the effect of rain found that the capacity of freeway systems was reduced, but did not address the effects of rain on the nature of traffic flows. Indeed, the substantial variation due to the intensity of adverse weather conditions is entirely rational so that its effects must be considered in freeway facility design. However, all of the data in Highway Capacity Manual(HCM) have come from ideal conditions. The primary objective of this study is to investigate the effect of rain on urban freeway traffic flows in Seoul. To do so, the relations between three key traffic variables(flow rates, speed, occupancy), their threshold values between congested and uncontested traffic flow regimes, and speed distribution were investigated. The traffic data from Olympic Expressway in Seoul were obtained from Imagine Detection System (Autoscope) with 30 seconds and 1 minute time periods. The slope of the regression line relating flow to occupancy in the uncongested regime decreases when it is raining. In essence, this result indicates that the average service flow rate (it may be interpreted as a capacity of freeway) is reduced as weather conditions deteriorate. The reduction is in the range between 10 and 20%, which agrees with the range proposed by 1994 US HCM. It is noteworthy that the service flow rates of inner lanes are relatively higher than those of other lanes. The average speed is also reduced in rainy day, but the flow-speed relationship and the threshold values of speed and occupancy (these are called critical speed and critical occupancy) are not very sensitive to the weather conditions.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.91-99
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• 2010

We used a multiplex PCR primer set composed of 11 microsatellite (MS) markers and two sexing markers for gender detection. Genomic DNA extracted from hair roots of 3,510 Hanwoo were genotyped. Based on the 11MS markers, no animals had identical genotypes(TGLA227, BM2113, TGLA53, ETF10, SPS115, TGLA122, ETH3, ETH225, BM1824 and INRA23). The expected probability of identity among genotypes of random individuals (PI), the probability of identity among genotypes from random half-sibs ($PI_{half-sibs}$) and among genotypes of random individuals, and the probability of identity among genotypes from random sibs ($PI_{sibs}$) were estimated as $1.31{\times}10^{-23}$, $2.52{\times}10^{-16}$and $1.09{\times}10^{-6}$, respectively using the API-CALC program, version 1.0. We successfully completed the genotype analysis of 3,510 Hanwoo with a 3.93% genotyping failure rate. It was revealed that extracting DNA from the hair root was a time-efficient and cost-effective method to collect specimens for DNA isolation from live animals. This method also minimized stress for the animals during specimen collection. Among the hair roots from the back, belly, upper tail and lower tail, 5~13 hair roots of the lower tail led to the best genotype analysis results. Finally, we established a 96-well-format method of DNA preparation applicable for high- throughput genotype analysis.

• Journal of Food Hygiene and Safety
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• v.34 no.3
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• pp.235-241
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• 2019

An analytical method was developed for the determination of an antibiotic fungicide, kasugamycin, in agricultural products (hulled rice, potato, soybean, mandarin and green pepper) using liquid chromatographytandem mass spectrometry (LC-MS/MS). Samples were extracted with methanol adjusted to pH 13 using 1 N sodium hydroxide, and purified with a HLB (hydrophilic lipophilic balance) cartridge. Linearity of a matrix-matched calibration curve using seven concentration levels, from 0.001 to 0.1 mg/kg, was excellent with a correlation coefficient ($R^2$) of more than 0.9998. The limits of detection (LOD) and quantification (LOQ) of instrument were 0.0005 and $0.001{\mu}g/mL$, respectively, and the LOQ of analytical method calculated as 0.01 mg/kg. The average recoveries at three spiking levels (LOQ, $LOQ{\times}10$, $LOQ{\times}50$, n=5) were in the range of 71.2~95.4% with relative standard deviation of less than 12.1%. The developed method was simple and all optimized results was satisfied with the criteria ranges requested in the Codex guidelines and Food Safety Evaluation Department guidelines. The present study could be served as a reference for the establishment of maximum residue limits (MRL) of kasugamycin and be used as basic data for safety management relative to kasugamycin residues in imported and domestic agricultural products.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.531-546
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• 2018

Air quality forecasting system with Asian dust emissions was developed in East Asia, and $PM_{10}$ forecasting performance of chemical transport model with Asian dust emissions was validated and evaluated. The chemical transport model (CTM) with Asian dust emission was found to supplement $PM_{10}$ concentrations that had been under-estimated in China regions and improved statistics for performance of CTM, although the model were overestimated during some periods in China. In Korea, the prediction model adequately simulated inflow of Asian dust events on February 22~24 and March 16~17, but the model is found to be overestimated during no Asian dust event periods on April. However, the model supplemented $PM_{10}$ concentrations, which was underestimated in most regions in Korea and the statistics for performance of the models were improved. The $PM_{10}$ forecasting performance of air quality forecasting model with Asian dust emissions tends to improve POD (Probability of Detection) compared to basic model without Asian dust emissions, but A (Accuracy) has shown similar or decreased, and FAR (False Alarms) have increased during 2017.Therefore, the developed air quality forecasting model with Asian dust emission was not proposed as a representative $PM_{10}$ forecast model in South Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.253-264
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• 2022

In this study, we investigated the occurrence of viral diseases in the early growth stage of soybean to establish management practices. We collected 83 soybean samples showing abnormal symptoms, approximately 3-4 weeks after seeding in the breeding field of the National Institute of Crop Science. Viruses were detected in the collected samples using reverse transcription polymerase chain reaction (RT-PCR) and metatranscriptome analysis of all those samples. The incidence of viral diseases in the field was less than 1% overall and up to 50% in certain cultivars and lines. RT-PCR and metatranscriptome analysis detected Soybean yellow mottle mosaic virus (SYMMV), Soybean mosaic virus (SMV), Soybean yellow common mosaic virus, Peanut stunt virus, and soybean geminivirus A (SGVA). Among these detected viruses, SYMMV and SMV were identified as major viruses causing infection in the early growth stage of soybean, with detection rates of 53.7% and 42.6%, respectively. Soybeans infected with SYMMV showed typical mosaic symptoms, whereas those infected with SMV showed a variety of symptoms such as mosaic, mottle, stunt, and chlorotic spots. Transmission characteristics of these viruses are variable, such that SMV is primarily transmitted by seeds, whereas SYMMV could be transmitted by insects, soil, and seeds. In this study, SGVA was detected in the early growth stage of soybean, and research on the current status and its effects on soybean after the early growth stage should be conducted.

• Journal of Intelligence and Information Systems
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• v.29 no.3
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• pp.185-209
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• 2023

With the advent of the 4th industrial revolution, various technologies have received much attention. Technologies related to the 4th industry include the Internet of Things (IoT), big data, artificial intelligence, virtual reality (VR), 3D printers, and robotics, and these technologies are often converged. In particular, the robotics field is combined with technologies such as big data, artificial intelligence, VR, and digital twins. Accordingly, much research using robotics is being conducted, which is applied to distribution, airports, hotels, restaurants, and transportation fields. In the given situation, research on human-robot interaction is attracting attention, but it has not yet reached the level of user satisfaction. However, research on robots capable of perfect communication is steadily being conducted, and it is expected that it will be able to replace human emotional labor. Therefore, it is necessary to discuss whether the current human-robot interaction technology can be applied to business. To this end, this study first examines the trend of human-robot interaction technology. Second, we compare LDA (Latent Dirichlet Allocation) topic modeling and BERTopic topic modeling methods. As a result, we found that the concept of human-robot interaction and basic interaction was discussed in the studies from 1992 to 2002. From 2003 to 2012, many studies on social expression were conducted, and studies related to judgment such as face detection and recognition were conducted. In the studies from 2013 to 2022, service topics such as elderly nursing, education, and autism treatment appeared, and research on social expression continued. However, it seems that it has not yet reached the level that can be applied to business. As a result of comparing LDA (Latent Dirichlet Allocation) topic modeling and the BERTopic topic modeling method, it was confirmed that BERTopic is a superior method to LDA.