• Korean Journal of Ecology and Environment
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• v.42 no.2
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• pp.200-211
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• 2009

A mathematical modeling program called Soil and Water Assessment Tool (SWAT) developed by USDA was applied to Kyongan stream watershed. It was run under BASINS (Better Assessment Science for Integrating point and Non-point Sources) program, and the model was calibrated and validated using KTMDL monitoring data of 2004${\sim}$2008. The model efficiency of flow ranged from very good to fair in comparison between simulated and observed data and it was good in the water quality parameters like flow range. The model reliability and performance were within the expectation considering complexity of the watershed and pollutant sources. The results of pollutant loads estimation as yearly (2004${\sim}$2008), pollutant loadings from 2006 were higher than rest of year caused by high precipitation and flow. Average non-point source (NPS) pollution rates were 30.4%, 45.3%, 28.1% for SS, TN and TP respectably. The NPS pollutant loading for SS, TN and TP during the monsoon rainy season (June to September) was about 61.8${\sim}$88.7% of total NPS pollutant loading, and flow volume was also in a similar range. SS concentration depended on precipitation and pollution loading patterns, but TN and TP concentration was not necessarily high during the rainy season, and showed a decreasing trend with increasing water flow. SWAT based on BASINS was applied to the Kyongan stream watershed successfully without difficulty, and it was found that the model could be used conveniently to assess watershed characteristics and to estimate pollutant loading including point and non-point sources in watershed scale.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.111-122
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• 2012

Establishment of the LFQC (Liquid Fertilizer Quality Certification) system is very urgent issue for recycling livestock manure as renewable resources in Korea faced with environmental problem of manure application to land due to intensive livestock farming. In this study, we investigated relevant laws and regulations on livestock manure fertilizer, certifications of eco-friendly agricultural products, government policies on livestock manure management to establish reasonable direction of Korean LFQC (Liquid Fertilizer Quality Certification) system. As a result from this study, the liquid fertilizers in 'LFQC' system could be classified as three levels according to the usage patterns in field; 1st. Individual Farm Level (IFL), 2nd. Joint Farm Level (JFL), and 3rd. Commercial Level (CML). And finally, we found some characteristics in 'Main Level-Grading Factors' of liquid fertilizer such as fertilizing value, harmfulness, stability, uniformity, economic effect, storage potential, commercial value, functionality. Those items were considered to be the key factors for the establishment of 'LFQC' system. More research on 'Evaluation Standards' for concrete guideline and on the 'Main Level-Grading Factors' be needed to complete Korean LFQC system.

• Journal of Animal Environmental Science
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• v.16 no.1
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• pp.1-12
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• 2010

This survey was conducted to investigate the status and strategy of swine manure utilization of 109 swine farms in the Gyeongnam, Korea. The personal properties of owner, types of swine buildings, facilities and equipment for manure management, conditions for manure recycling and farming for recycling resources were surveyed. Age of farm owners were occupied as 44.1% for 50s followed by the 60s with one-forth and 40s with 22.9%. Educational background of farm owners, a high school graduate makes up the largest proportion of farm owners followed by a college graduation with 35.8%. The swine manure collection methods were occupied as 34.9% with totally slurry system and more than 50% slurry system with 34.9% of farms. The manure management cost per ton were occupied as more than two-third with 10,000 won~15,000 won. The cost will pay for manure management, 10,000 won~15,000 won per ton makes up the largest proportion of farm owners. Separator, loader and vehicle to collection, transportation of liquid manure were occupied as 72.5%, 44% and 10.1%, respectively. Recognition of the farming for recycling resources were occupied as 37.6%, however, 25.8% of swine farm owners don't know that. More than sixty percent of swine farms will take a recycling system according to the farming for recycling resources. Conclusively, we have a suggestion in order to promotion of the farming for recycling resources in the Gyeongnam with increasing the portion of recycling of swine manure in each county and revitalizing the marketing of the liquid and solid swine manure fertilizers.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.1
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• pp.41-49
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• 2016

The objective of this study was to determine the effect of different pregnancy stages on the eating and ruminating behavior of Hanwoo heifers (Bos taurus coreanae). A total of twelve Hanwoo heifers were divided into four groups depending on pregnancy stage: C: before pregnancy, 9 months old, T1: 3 months pregnant, 16 months old, T2: 6 months pregnant, 19 months old, T3: 9 months pregnant, 22 months old (3 replicates per group). Concentrate of 1% of the body weight was fed to them. Roughage was provided at ad libitum to all treatments. Our results revealed that the intake of roughage was the highest in the T3 group (at 3.68 kg) and the lowest in the C group (at 1.02 kg, p<0.05). Total intake in the order from high to low was: T3 > T2 > T1 > C (p<0.05). The rate of dry matter intake compared to body weight (DMI/BW, %) from high to low order was: T3 > T2 > T1 > C (p<0.05). Eating time, ruminating time, and chewing time were the highest in T3 group (p<0.05). Resting time was the highest in C group (p<0.05). The number of bolus and the number of total chews were significantly higher in T3 compared to those in other groups. However, ruminating time per bolus was not significantly difference among groups. The number of chews per bolus from high to low order was: C > T1 > T3 > T2 (p<0.05). The number of bolus per minute was not significantly different among groups. The number of drinking and the number of defecating were significantly higher in C and T1, respectively (p<0.05). However, the number of urinating had no effect according to pregnancy stage. Eating rate and chewing efficiency were significantly higher (p<0.05) in accordance with pregnancy stage (T3 > T2 > T1 > C). Ruminating efficiency was significantly (p<0.05) higher T1 than that in other groups.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.52-59
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• 2014

This study was conducted to estimate the Hanwoo carrying capacity when whole crop wheat, as a winter forage crop, was grown on mixed-sowing of legume forage and by applying cattle manure on the productivity and feed value of whole crop wheat during the period of 2012~2013. The experiment was conducted in a split plot design with three replications. The main plots consisted of three different culture methods such as whole crop wheat and mixed sowing combination with hairy vetch or forage pea. The subplots consisted of four different applications of cattle manure (0, 50, 100 and 150 kg N/ha). The annual amount of dry matter (DM) of whole crop wheat in Gyeongju were higher than those of in Gyeongsan and Yeongju, and the mixed-sowing of hairy vetch mixture was the highest (p<0.05) compared with the single-sowing of whole crop wheat and mixed-sowing of legume in Gyeongju. The DM amounts were increased proportionately corresponded to the applying level of cattle manure, and was found to be significantly (p<0.05) high at the level of 100 and 150 kg/ha groups. With the feed value of forage, the crude protein (CP) contents tended to be higher in the mixed-sowing of legume than the single-sowing of whole crop wheat at the wintering experimental sites of legume. For whole crop wheat, total digestible nutrients (TDN) content was the highest in the mixed sowing plots of forage pea in Gyeongsan; however, there was no significant differences among the single-sowing of whole crop wheat. The carrying capacity of Hanwoo (head/ha) was higher (p<0.05) in Gyeongju (3.83 head) than that in Gyeongsan (3.11) and Yeongju (1.35). Further, the carrying capacity in the single-sowing of whole crop wheat was lower than that in the mixed-sowing of legume, and the hairy vetch was the highest among the mixed-sowing groups (p<0.05). Overall, the present results recommend taking into account the wintering for the mix-sowing of legume in Gyeongbuk province. The cattle manure may be applied for legume in the wintering unavailable regions. In addition, applying cattle manure at the level of 100~150 kg/ha and the mix-sowing of legume may increase the productivity per unit area and feed value, including the CP, for improving the carrying capacity of Hanwoo.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.21-25
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• 2014

Singwangok, a new single cross variety, was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2012. This hybrid, consisting of a high yield of grain, was produced by crossing two inbred lines, KS172 and KS173. KS172 is the seed parent and KS173 is the pollen parent of Singwangok. It is a yellow-orange intermediate maize hybrid (Zea mays L.). After the preliminary yield trial and advanced yield trial of Singwangok (Suwon185) in Suwon for 2 years, the regional yield trial of that was subsequently carried out for its growth characteristics and yield at 3 different locations from 2010 to 2012. It was named as Singwangok. The silking date of Singwangok is similar to the check hybrid, Jangdaok. The plant height of Singwangok is similar to Jangdaok, but its ear height ratio is lower than that of Jangdaok. Moreover, it has a resistance to lodging. The ear number per 100 plants of Singwangok is more 17 than that of Jangdaok, whereas the ear length of Singwangok is similar to Jangdaok. Further, the weight of 100 seeds of Singwangok is similar to Jangdaok. It has a moderate resistance to southern leaf blight (Bipolaris maydis) and a strong resistance to northern leaf blight (Exserohilum turcicum). Furthermore, it has a moderate resistance to the black streaked dwarf virus (BSDV), ear lot and corn borer. The grain yield of Singwangok, 7.81 ton/ha, was similar to that of Jangdaok. The seed production of Singwangok was well processed due to the good match during crossing between the seed parent, KS172 and the pollen parent, KS173, in Yeongwol; the F1 seed yield was 3.84ton/ha. Singwangok would be a suitable cultivar to all plain areas in Korea.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.233-239
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• 2010

This study was conducted to examine the anticancer activities of Berberis koreana extracts according to different extraction processes. The highest extraction yield obtained was 8.26% following extraction by ultrasonification at 60 kHz and $60^{\circ}C$ followed by high pressure at 500MPa. Generally, the extracts from the ultrasonification process showed relatively low cytotoxicities against the human normal cell line, HEK293 showing as low as 15%. This extract inhibited the growth of the digestive related organs cell lines, human stomach adenocarcimoma cell and human epithelial adenocarcinoma cell by up to 80% when administered at 1.0 mg/mL, and showed 2.5-3.5 of selectivity. It was also found that this extract induced the production of nitric oxide levels as high $37.87\;{\mu}M$ from macrophages. For the in vivo experiment using ICR mice, the total serum IgG levels of mice treated with B. koreana extracts from ultrasonification extraction were increased by up to 57 ng/mL. The survival time of this group was longer than that of the other group after the injection of Sarcoma-180 and the increment of their body weights was also greatly suppressed. In addition, the extract showed the highest tumor inhibition activities, leading to a reduction of 78.47%. These results indicate that the highest activities of B. koreana associated with this extraction process can be significantly improved.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.566-574
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• 2014

This study was conducted to compare the physicochemical composition and fermentation conditions of sliced, dried radish kimchi with flying fish roe (DFFR). The levels of crude protein, crude lipid, and crude ash in DFFR were higher than those in sliced, dried radish kimchi without flying fish roe (control). DFFR also contained higher levels of Fe and Ca, compared to the control. The inosine monophosphate (IMP) content of DFFR and control was 5.63 and 2.64 mg/100 g, respectively. The polyunsaturated fatty acid and DHA contents in DFFR were approximately 5 and 23 times higher than those in the control, respectively. The major free amino acids contained in these samples were arginine, proline, alanine, leucine, and valine. The number of cells belonging to the Leuconostoc species in DFFR was higher than that in the control. In sensory evaluation studies, DFFR scored the highest in terms of appearance, flavor, taste, and texture.

• Journal for History of Mathematics
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• v.22 no.2
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• pp.27-52
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• 2009

This article discusses the contributions of the leader Oswald Veblen, who was the president of AMS during 1923-1924. In 2006, Korea ranked 12th in SCIE publications in mathematics, more than doubling its publications in less than 10 years, a successful model for a country with relatively short history of modern mathematical research. Now there are 192 four-year universities in Korea. Some 42 of these universities have Ph.D. granting graduate programs in mathematics and/or mathematical education in Korea. Rapid growth is observed over a broad spectrum including a phenomenal performance surge in International Mathematical Olympiad. Western mathematics was first introduced in Korea in the 17th century, but real significant mathematical contributions by Korean mathematicians in modern mathematics were not much known yet to the world. Surprisingly there is no Korean mathematician who could be found in MaC Tutor History Birthplace Map. We are at the time, to have a clear vision and leadership for the 21st century. Even with the above achievement, Korean mathematical community has had obstacles in funding. Many people thinks that mathematical research can be done without funding rather unlike other science subjects, even though they agree fundamental mathematical research is very important. We found that the experience of early American mathematical community can help us to give a vision and role model for Korean mathematical community. When we read the AMS Notice article 'The Vision, Insight, and Influence of Oswald Veblen' by Steve Batterson, it answers many of our questions on the development of American mathematics in early 20th century. We would like to share the story and analyze its meaning for the development of Korean Mathematics of 21st century.

• Korean Journal of Food Science and Technology
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• v.45 no.1
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• pp.111-119
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• 2013

Eleven mycotoxins, including aflatoxins, ochratoxin A, fumonisins, zearalenone, T-2 toxin, deoxynivalenol, and HT-2 toxin, were analyzed simultaneously in rice, barley, and maize produced in 2011 by liquid chromatography coupled with triple quadrupole mass spectrometry (LC/MS/MS). Limits of detection (LOD) are 0.2 ${\mu}g/kg$ for aflatoxin $B_1$, and $G_1$, 0.3 ${\mu}g/kg$ for aflatoxins $B_2$, and $G_2$, 0.1 ${\mu}g/kg$ for ochratoxin, fumonisins, zearalenone, and T-2 toxin and 3.0 ${\mu}g/kg$ for deoxynivalenol and HT-2 toxin. Limits of quantification (LOQ) were 0.6 ${\mu}g/kg$ for aflatoxins $B_1$, and $G_1$, 0.9 ${\mu}g/kg$ for aflatoxins $B_2$, and $G_2$, 0.3 ${\mu}g/kg$ for ochratoxin, fumonisins, zearalenone, and T-2 toxin and 10.0 ${\mu}g/kg$ for deoxynivalenol and HT-2 toxin. Recoveries for 11 mycotoxins ranged from 70.45 to 111.11%. Fumonisins, deoxynivalenol, and zaeralenone were detected from 0.9 to 334.0 ${\mu}g/kg$ in the polished rice, barley and raw corn cultivated in Korea. Other mycotoxins were not detected. Deoxynivalenol contamination was mainly found in barley (24 out of 43 samples) and the average value in positive samples was 113.30 ${\mu}g/kg$.