• Weed & Turfgrass Science
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• v.3 no.4
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• pp.253-261
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• 2014

In this study, we investigated several chemical and physical characteristics of 4 weed seed fibers; Hemistepta lyrata (HEMLY), Imperata cylindrica var. koenigii (IMPCK), Metaplexis japonica (METJA) and Typha latifolia (TYPLA). In chemical composition, there were 74 (TYPLA)-88.5% (METJA) of holocellulose, 17 (IMPCK)-24% (METJA) of lignin, 0.22 (METJA)-4.2% (IMPCK) of ash, 2.2 (HEMLY)-7.8% (IMPCK) of hot water extractives and 0.4 (IMPCK)-6.3% (TYPLA) of solvent extractives. Alpha-cellulose proportion to holocellulose was similar among weed seed fibers as 45-48%. The crystallinity index (CI) of raw seed fibers was 53.2 (TYPLA)-65.9% (HEMLY). However, CI of the chemical treated fibers (EDA fibers) was a little increased and showed 61.1 (IMPCK)-71.8% (METJA). The maximum thermal decomposition temperature (MTDT) of the raw seed fibers were 312, 321.8, 331.5 and $341.6^{\circ}C$ in METJA, TYPLA, HEMLY and IMPCK, respectively. But the MTDT of the EDA fibers were 327, 327, 341.7 and $360.0^{\circ}C$ in HEMLY, TYPLA, METJA and IMPCK, respectively. Taken together, they showed a similar or better characteristics compared to the reported or commercial natural fiber resourses. Accordingly, they seem to be practically applicable as renewable resources for a new natural fibers.

• Journal of Food Hygiene and Safety
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• v.26 no.4
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• pp.315-321
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• 2011

This study was performed to investigate contamination levels of aflatoxins, the secondary metabolites produced by fungi Aspergillus flavus and A. parasiticus, in herbal medicine. Herbs is susceptible to these fungi infections through its growth harvest, transport and storage. This study determine the aflatoxin $B_1$, $B_2$, $G_1$ and $G_2$ levels by HPLC-florescence detector coupled with photochemical enhancement in 558 samples herbal medicine distributed in Korea and China. Also, We checked a transfer ratio of aflatoxins from raw herbal medicines to herbal medicine extract. Hot water extraction of herbal medicines was prepared by air pressure and high pressure condition. The analytical method for aflatoxins was validated in this method. In results recoveries of the analytical method were ranged from 67.4% to 96.2% and, limits of detection and quantitation for aflatoxins were $0.015{\sim}0.138\;{\mu}g/kg$ and $0.046{\sim}0.418\;{\mu}g/kg$, respectively. According to the results of monitoring on aflatoxins in herbal medicine, aflatoxins 1.7 ug/kg $B_1$ and 0.9 ug/kg $G_1$ were detected in only one sample of Strychni Ignatii Semen, and 0.8 ug/kg $G_1$ in Strychni Semen. About 13.6~51.3% of aflatoxins were transferred to hot water extract. Although the detected levels are under the permitted levels for aflatoxins in herbal medicine, these amounts should be considered in regard to overall daily exposure to mycotoxins.

• Journal of Intelligence and Information Systems
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• v.22 no.4
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• pp.19-43
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• 2016

This study examines the causes of the Asian exchange rate crisis and compares it to the European Monetary System crisis. In 1997, emerging countries in Asia experienced financial crises. Previously in 1992, currencies in the European Monetary System had undergone the same experience. This was followed by Mexico in 1994. The objective of this paper lies in the generation of useful insights from these crises. This research presents a comparison of South Korea, United Kingdom and Mexico, and then compares three different models for prediction. Previous studies of economic crisis focused largely on the manual construction of causal models using linear techniques. However, the weakness of such models stems from the prevalence of nonlinear factors in reality. This paper uses a structural equation model to analyze the causes, followed by a neural network model to circumvent the linear model's weaknesses. The models are examined in the context of predicting exchange rates In this paper, data were quarterly ones, and Consumer Price Index, Gross Domestic Product, Interest Rate, Stock Index, Current Account, Foreign Reserves were independent variables for the prediction. However, time periods of each country's data are different. Lisrel is an emerging method and as such requires a fresh approach to financial crisis prediction model design, along with the flexibility to accommodate unexpected change. This paper indicates the neural network model has the greater prediction performance in Korea, Mexico, and United Kingdom. However, in Korea, the multiple regression shows the better performance. In Mexico, the multiple regression is almost indifferent to the Lisrel. Although Lisrel doesn't show the significant performance, the refined model is expected to show the better result. The structural model in this paper should contain the psychological factor and other invisible areas in the future work. The reason of the low hit ratio is that the alternative model in this paper uses only the financial market data. Thus, we cannot consider the other important part. Korea's hit ratio is lower than that of United Kingdom. So, there must be the other construct that affects the financial market. So does Mexico. However, the United Kingdom's financial market is more influenced and explained by the financial factors than Korea and Mexico.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.307-313
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• 2013

This study was carried out to investigate the residual characteristics of fungicide azoxystrobin and difenoconazole in Prunus mume fruits, and establish pre-harvest residue limits (PHRL) based on dissipation and biological half-lives of fungicide residues. The fungicides were sprayed onto the crop at recommended dosage once and 3 times in 7 days interval, respectively. The samples were harvested at 0, 1, 2, 4, 6, 8, 10, 12 and 14 days after treatment. These residual pesticides were extracted with QuEChERS method, clean-up with $NH_2$ SPE cartridge, and residues were analyzed by HPLC/DAD and GLC/ECD, respectively. Method quantitative limits (MQL) of azoxystrobin were 0.03 mg $kg^{-1}$ and of difenoconazole were 0.006 mg $kg^{-1}$. Average recovery were $93.2{\pm}2.49%$, $85.5{\pm}1.97%$ for azoxystrobin at fortification levels at 0.3 and 1.5 mg $kg^{-1}$, and $100.8{\pm}6.74%$, $87.6{\pm}9.92%$ for difenoconazole at fortification levels at 0.06 and 0.3 mg $kg^{-1}$, respectively. The biological half-lives of azoxystrobin were 5.9 and 5.2 days at recommended dosage once and 3 times in 7 days interval, respectively. The biological half-lives of difenoconazole were 9.3 and 8.0 days at recommended dosage once and 3 times in 7 days interval, respectively. The PHRL of azoxystrobin and difenoconazole were recommended as 5.32 and 1.64 mg $kg^{-1}$ for 10 days before harvest, respectively.

• Food Science and Preservation
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• v.14 no.2
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• pp.119-123
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• 2007

Sprays containing chitosan, grain amino acids, or wood vinegar, were applied to vine leaves of the Campbell Early grape variety, and effects on the quality and storability of grapes were investigated. Weights of grape clusters and individual bemies did not differ significantly from the values seen when traditional agnicultural chemical treatment was used. The percentage of clusters over 300g in weight was, however, higher after spraying with chitosan, grain amino acids, or wood vinegar, than after agricultural chemical treatment, Grape moisture contents, levels of soluble solids, and reducing sugar concentrations, did not differ when the traditional treatment and the newer sparys were compared. Among minerals, the levels of potassium, iron and zinc measured in fresh grapes were increased by the clitosan, grain amino acids, and wood vinegar spray. After 8 weeks of MA storage, reducing sugar levels decreased, and titratable acidities increased, compared to levels measured at the beginning of storage. This was true regardless of the method of vine treatment the hardness of berries decreased slightly over 4-6 weeks of storage, and increased thereafter. The weight losses of grapes were relatively low(0.28-0.35%) on storage after any vine treatment tested. Grapes from vines sprayed with chitosan or grain amino acids showed a lower decay rate than did fruit from vines that had received a traditional agricultural chemical treatment. Sensory evaluation results indicated that the marketability of grapes from vines treated with traditional agricultural chemicals was better than that of grapes from vines sprayed with chitosan, grain amino acids, or wood vinegar.

• Economic and Environmental Geology
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• v.43 no.5
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• pp.467-475
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• 2010

The Landsat and ASTER data have been used in mineralogical and lithological studies, and they have also proved to be useful tool in the initial steps for mineral exploration throughout Nevada mining district, US. Huge pyrophyllite quarry mines, including Jungang, Samsung, Kyeongju, and Naenam located in the southeastern part of Gyeongsang Basin. The geology of study area consists mainly of Cretaceous volcanic rocks, which belong into Cretaceous Hayang and Jindong Group. They were intruded by Bulgugsa granites, so called Sannae-Eonyang granites. To extraction of Ratio model for pyrophyllite deposits, tuffaceous rock and pyrophyllite ores from the Jungang mine used in reflectance spectral analysis and these results were re-sampled to Landsat and ASTER bandpass. As a result of these processes, the pyrophyllite ores spectral features show strong reflectance at band 5, whereas strong absorption at band 7 in Landsat data. In the ASTER data, the pyrophyllite ores spectral features show strong absorption at band 5 and 8, whereas strong reflectance at band 4 and 7. Based on these spectral features, as a result of application of $Py_{Landsat}$ model to hydrothermal alteration zone and other exposed sites, the DN values of two different areas are 1.94 and 1.19 to 1.49, respectively. The differences values between pyrophyllite deposits and concrete-barren area are 0.472 and 0.399 for $Py_{ASTER}$ model, 0.452 and 0.371 for OHIb model, 0.365 and 0.311 for PAK model, respectively. Thus, $Py_{ASTER}$ and $Py_{Landsat}$ model proposed from this study proved to be more useful tool for the extraction of pyrophyllite deposits relative to previous models.

• Journal of Food Hygiene and Safety
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• v.33 no.5
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• pp.361-368
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• 2018

N-nitrosamines are probable or possible human carcinogens, which are produced by the reaction between secondary amines and nitrogen oxide in the acidic environment or by heating. Common risk assessment procedure involves the comparison between exposures expressed in the unit, mg/kg body weight/day and the Health-Based Reference dose expressed in the same unit. This procedure is suitable for the policy decision-making and is considered as inappropriate for the consumers to get information about their dietary decision-making. Therefore, the distributions of NDMA (N-nitrosodimethylamine), NDBA (N-nitrosodibutylamine), the six N-nitrosamines (NDMA, NDBA, NDEA (N-nitrosodiethylamine), NPYR (N-nitrosopyrrolidine), NPIP (N-nitrosopiperidine), and NMOR (N-nitrosomorpholine) in the menus grouped based on the presence of main ingredients and cooking methods were analyzed to generate consumer-friendly information regarding food contaminants. Recipes and intakes were taken from 2014 to 2016 KNHANES (The Korean National Health and Nutrition Examination Survey) and only the data from ages of 7 years or older were used. The contamination data were collected from the 2014~2016 Total Diet Study and all the analysis were performed using R software. Rockfish, eel, anchovy broth and pollock were mainly exposed to N-nitrosamines. In terms of cooking methods, soups and stews appeared to contain the highest amount of N-nitrosamines. Cereals, fruits, and dairy products in the ingredient categories, and rice dishes and rice combined with others in recipe categories had the lowest level exposure to N-nitrosamines. In case of N-nitrosamines, unlike other cooking related food contaminants, boiled dishes such as soups and stews and dishes mainly consisting of fishes and shellfishes had highest level of exposure, showing a large discrepancy with the previous thought of processed meat is the main source of N-nitrosamines.

• Korean Journal of Remote Sensing
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• v.40 no.4
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• pp.363-375
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• 2024

Waterbody change detection using satellite images has recently been carried out in various regions in South Korea, utilizing multiple types of sensors. This study utilizes optical satellite images from Landsat and Sentinel-2 based on Google Earth Engine (GEE) to analyze long-term surface water area changes in four monitored small and medium-sized water supply dams and agricultural reservoirs in South Korea. The analysis covers 19 years for the water supply dams and 27 years for the agricultural reservoirs. By employing image analysis methods such as normalized difference water index, Canny Edge Detection, and Otsu'sthresholding for waterbody detection, the study reliably extracted water surface areas, allowing for clear annual changes in waterbodies to be observed. When comparing the time series data of surface water areas derived from satellite images to actual measured water levels, a high correlation coefficient above 0.8 was found for the water supply dams. However, the agricultural reservoirs showed a lower correlation, between 0.5 and 0.7, attributed to the characteristics of agricultural reservoir management and the inadequacy of comparative data rather than the satellite image analysis itself. The analysis also revealed several inconsistencies in the results for smaller reservoirs, indicating the need for further studies on these reservoirs. The changes in surface water area, calculated using GEE, provide valuable spatial information on waterbody changes across the entire watershed, which cannot be identified solely by measuring water levels. This highlights the usefulness of efficiently processing extensive long-term satellite imagery data. Based on these findings, it is expected that future research could apply this method to a larger number of dam reservoirs with varying sizes,shapes, and monitoring statuses, potentially yielding additional insights into different reservoir groups.

• Journal of agricultural medicine and community health
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• v.25 no.1
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• pp.51-63
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• 2000

Ten Dongs were selected according to the systematic cluster sampling in Koryong Gun, and the survey was conducted on 571 women in the age between 30-69 years. The first survey was performed for 6 days between August 27 to September 1, 1999 with the investigation rate of 60.3%, and the second survey was performed in November with the investigation rate of 91.8%. The contents of survey included demographic characteristics, health behaviors, dyspepsia symptom score, sleeping induction time and the degree of sleep satisfaction, and degree of stress in the subjects. The dyspepsia symptom score was in the average 13.4 points out of a total 44 points and was the highest in the 50-59 year-old age group with 13.9 points. The sleep induction time was in the average of 35 minutes and was the highest in the 50-59 year-old age group with 40.9 minutes; the degree of sleep satisfaction was in the average of 7.9 points and was the lowest in the 50-59 year-old age group with 7.5 points. The stress score was in the average of 18.3 points and was highest in those subjects in their 40's and 50's with 18.7 points. When the correlation among the stress score, the degree of sleep satisfaction and dyspepsia symptom score was analyzed, the results showed that he stress score and the degree of sleep satisfaction showed a significant negative correlation and that the stress score and dyspepsia symptom score showed a significant positive correlation. Also, a significant negative correlation was found between the degree of sleep satisfaction and dyspepsia symptom score. According to each age group, a significant correlation was revealed among the stress score, dyspepsia symptom score and the degree of sleep satisfaction in those subjects over 40 years of age compared to those subjects who were younger than 40 years of age. As for educational level, the correlation among the stress score, the degree of sleep satisfaction and dyspepsia symptom score was higher in those subjects with less than middle school education compared to those subjects with more than high school education. When those factors that effects on the dyspepsia symptom score were analyzed with multiple regression, the results showed that the level of stress and chronic diseases were selected as significant variables. When those factors that affected on the degree of sleep satisfaction were analyzed, the sleep induction time and presence of chronic diseases and stress were selected as significant variables. Those women in their 50's who live in rural areas showed the highest level of stress, lowest the degree of sleep satisfaction, and highest level of dyspepsia, indicating that they need stress management. Also, since stress was showed to be a significant variable effecting on dyspepsia or the degree of sleep satisfaction, it is concluded that health promotion is possible through stress management. More studies are needed in the future on coping resources that would strengthen coping against stress, and by conducting studies on stress and related factors on community people, the measures of mental health promotion need to be developed.