• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.229-234
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• 2012

Disinfecting contaminated swine manure with FMD (Foot-and-Mouth Disease) and pathogenic viruses is very important for maintaining sanitized environment. However, very few research reported on this subject, especially post-disinfection to utilize the wastes as a renewable resource. This research is carried out to obtain basic information for chemical treatment in FMD SOP (Standard Operating Procedure, Korea) of contaminated swine manure. Using lime, sodium hydroxide, citric acid and hydrochloric acid, described in FMD SOP, the effects of chemical treatments on livestock manure were compared in this paper. Four combinations of alkali-acid treatments and four kinds of acid-alkali combinations were tested to find out the effective method. Total coliform bacteria in contaminated swine manure, $1.6{\times}10^4$ CFU/100 ml, decreased to the range of 1/1000~1/100 in all treatments. Some specific disinfectants increases BOD (Biochemical Oxygen Demand) and EC(Electric Conductivity), especially, alkaline treatments increases ammonia level than acid treatments. These findings suggest that the treatment methods should be considered as an important environmental factor in post-disinfection of contaminated animal manure with pathogenic microorganisms.

• Journal of Korean Society of Transportation
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• v.33 no.4
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• pp.337-347
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• 2015

Since the application of roundabouts by 2010 have been started, more than 350 roundabouts were installed in Korea. Recently the types of constructed roundabouts become various, and the intersection conditions for installing roundabouts were also various. However, there were some difficulties to install roundabouts around school zone due to safety problems. In this study, appropriate distance from adjacent signal crosswalks to roundabouts were estimated for securing pedestrian safety and operation efficiency around school zone. With the analyses, the minimum distance standard was suggested to obtain operational effectiveness of roundabout according to traffic volume, traffic flow, pedestrian green time and secures pedestrian safety and convenience. In this paper, average delay of roundabout as various length of distances between an adjacent crosswalk and a roundabout as different pedestrian signal times, traffic volumes, traffic flow rates were analyzed. Through this study, it was found that about four times of delay in a roundabout was generated if there was adjacent signal crosswalk. However if there is enough distance between an adjacent crosswalk and a roundabout, the value of increasing delay on roundabouts with adjacent a signalized crosswalk can be considerably reduced. Critical value of the distance between a roundabout and a signal crosswalk in case of roundabouts within 200-500 vehicle/hour/lane entry traffic flow, 20-40% of left turn traffic, and over 15 seconds pedestrian green time was about 50 meters. In conclusion, if there is minimum 40 meter distance from roundabouts, adjacent signal crosswalks can be installed and operated for students' safety around school zone.

• Journal of The Korean Society of Grassland and Forage Science
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• v.6 no.1
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• pp.49-52
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• 1986

The objective of this study was to find out the productivity of F_2 material derived from F_1 hybrid Maize (Zea mays L.) by multiplication and their response to plant population. Suweon 19 and Junju-Ok were grown at three population densities. Populations were ca. 8.3, 10.4 and 13.9 thousand plants per 10a. The results are summarized as follows; 1. The number of barren plants differed significantly for the two generations but other yield components comparisons were not significant at P(0.05). 2. Ear and TDN yield were higher from the $F_1$ hybird of Suweon 19 than from the F_2 material, while yields of Jinju-Ok and stover yield of both hybrids were not affected by generation. 3. Plant and ear height were not affected by population density but barren plants were increased at high population. Length and weight of a ear, and ear (including cobs)-to-stover ratio decreased with increased population. 4. Increasing population density resulted in significant decrease in ear and TDN yield, while stover yield not decreased.

• Korean Journal of Soil Science and Fertilizer
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• v.15 no.2
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• pp.101-109
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• 1982

An attempt to determine the optimum levels of P and K fertilizers application for Tong-il lines (indica${\times}$Japonica) was made with the data obtained from the farm fields during 1976 to 1979. The detailed interpretation to obtains relationships between fertilizer recommendation of P and K with their balance with Ca and Mg contents in soil were made using yield data obtained in 1977. The results were summarized as follows : 1. The optimum rates of P and K fertilizer application varied with the kinds of paddy soils showing the ranges of 6.6-11.4 kg/10a for P (as $P_2O_5$) and 7.0-11.3 kg/10a for K (as $K_2O$). The amounts of optimum fertilizers increased in the order of unmatured soil, normal soil, sandy soil, saline soil, poorly drained soil for P, and unmatured soil, poorly drained soil, sandy soil, normal soil, saline soil for K. 2. The yield increment at the optimum levels of P and K in comparison with no fertilizer application were 3,5-7.5% for P and 2.1-9.1% for K. The effectiveness of P was greatest in the unmatured soils and that of K was greatest in the poorly drained soils, and in the saline soil, that of P and K was relatively high. 3. According to relationship between relative yield index and soil testing value, the critical $P_2O_5$ contents which showed the yield response in soil were about 100 ppm for normal soil and 200ppm for sandy soil. That of exchangeable K/Ka+Mg ratio in soil were about 0.08 for normal paddy soil and over 0.08 for sandy soil, and those for poorly drained soils were not obtained in the ranged below 0.08. 4. The regression equations of fertilizer recommendation for different soils were obtained between the available $P_2O_5$ in soil or ratio of K to base including Ca and Mg in soil (x) and the amount (Y) of P and K fertilizers applied. The equations for phosphorus recommendation were Y=11.27C-0.048x for normal paddy soil and Y=13.383-0.061x for sandy soil, and those for potassium recommendation were Y=9.526-0.569x for normal paddy soil, Y=11.727-1.004x for sandy soil, and Y=12.574-0.558x for poorly drained soil, respectively.

• Korean Journal of Animal Reproduction
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• v.25 no.2
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• pp.125-130
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• 2001

This study was performed to report a direct dose dependent stimulatory effect of the Flavonoid(F) on basal testosterone secretion and a dose dependent effect on LH induced testosterone production by Leydig cell of matured rats in vitro culture. F was obtained kom the Rhus vernicifua through aceton extraction and silica gel adsorption column chromatography. Leydig cells (1$\times$10$^{6}$ cells/well) from 12 weeks old rats were incubated with or without F(0, 20, 40, 80, 160 ng) or insulin-like growth factor-I(IGF-I) in the presence or absence of LH(10, 100ng). 1. The maximal stimulatory concentrations of testosterone in culture media were showed at 24hr of culture. but these testosterone level were decreased at 36 hr of culture. 2. Flavonoid(80ng) were significantly(P ＜ 0.05) increased testosterone production compared with control groups for 12 hr culture. 3. Testosterone secretion by Leydig cells stimulated with LH(10, 100ng) for 6 hr and 12hr culture compared with 3 hr culture. 4. LH 10 ng augmented testosterone were increased by addition of F 40 ng for 12 hr culture. 5. F(0 and 40 ng) also enhanced LH 10 ng stimulated testosterone for 3 hr Leydig cells culture. 6. Addition of IGF-I 100 ng to the culture medium for 6 hr were increased the concentration of testosterone by Leydig cells stimulated with 100 ng LH. These results indicate that Flavonoid has a direct stimulatory effect on basal testosterone secretion in rat Leydig cells, and also modulates LH mediated testosterone. Therefore, Flavonoid may act as a modulator on gonadal development or gonadal steroidogenesis in direct or indirect.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.6
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• pp.608-616
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• 1992

This study was designed to observe the effects of feeding the mixed oils of the sardine oil containing n-3 EPA, DHA and the safflower oil which is rich in n-6 linoleic acid on the improvement of the lipids and enzyme activities of serum in rats. Experimental oils mixed with 16% butter (control group) and 8% butter + 8% olive oil, 8% butter and various level of sardine and safflower oils were administered to the male rats of the Sprague Dawley for 4 weeks. The activities of aspartate aminotransferase (AST, EC 2.6.1.1), alanine aminotransferase (ALT, EC 2.6.1.2), lactate dehydrogenase (LDH, EC 1.1.1.27) and alkaline phosphatase (ALP, EC 3.1.3.1) in serum were significantly decreased in the all experimental groups than in the control groups, and activities of ALT and LDH were remarkably lower in the group 5 (4% sardine 0il + 4% safflower oil). Concentrations of total cholesterol and HDL-cholesterol in serum were lower in the other groups than in the dontrol groups, and particularly, lowest in the group 5. Concentrations of LDL, LDL-cholesterol, phospholipid and triglyceride in serum were lower in the all experimental groups than in the control group. Concentrations to total cholesterol and cholesteryl ester in serum were lowest in the group 5. The ratio of cholesteryl ester to total cholesterol was remarkably high in the control group, while group 2 (8% olive oil) was the lowest. From this results, the feeding equal quantity mixed oil with n-3 PUFA rich sardine oil and n-6 PUFA rich safflower oil were effective on the improvement of the lipid composition in the serum. It might be due to the effects of appropriate ratios of P/S, 0.85 and n-6/n-3P, 2.85 in the test lipids.

• Journal of Preventive Medicine and Public Health
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• v.9 no.1
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• pp.129-138
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• 1976

The causes and problems underlying deaths in perinatal period are often similar and might be expected to yield to same type of preventive measures. This is one of the reasons for attempting to develop a reporting of perinatal mortality and its related matters. This study aims at figuring out the biologic risk factors onto the perinatal death. Considering stillbirth and early neonatal mortality separately, considerable associations between stillbirth and reproductive history of women, are observed, ana it is found that prematurity is the the far most important factor in the early neonatal mortality.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.2
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• pp.124-128
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• 2016

The objective of this research was to determine the effects of harvesting frequency and fertilization levels on botanical composition, dry matter yield, and forage feed compositions of Alpine grassland at 800 m altitude. This research lasted for three years at National Alpine Agricultural Research Institute in Pyeongchang with two harvesting frequency schedules (two and three times annually) and two levels of fertilizer application (conventional level of fertilizer at 280-200-240 kg/ha and a lower level of fertilizer at 200-200-200 kg/ha for N, $P_2O_5$, and $K_2O$). Mixture combinations with seeding rate (kg/ha) were as follows: Orchardgrass 18, Tall fescue 9, Timothy 8, Kentucky bluegrass 3, and Ladino Clover 2. The gramineae ratio ranged from 93.2 to 95.3%. Therefore, gramineae forage was considered as the dominant plant in this experiment. No significant (p>0.05) difference was observed in forage dry matter yield between the two harvesting frequency treatments (two times at 9.8 ton/ha and three times at 8.6 ton/ha). However, forage dry matter yield in the two times of harvesting frequency tended to be greater than that in the three times of harvesting frequency. Significantly (p<0.05) higher forage dry matter yield in the standard fertilization level group than the lower fertilization level group (9.8 ton/ha vs. 8.7 ton/ha) was observed. However, there was no significant (p>0.05) difference in forage crude protein concentration between the two harvesting frequency treatment groups, although the concentration in the group with three times of harvesting frequency tended to be higher. In contrast, crude fiber concentration in the group with two times of harvesting frequency tended to be higher, although the difference was not statistically significant (p>0.05). Crude protein, ether extract, crude fiber, and organic matter concentrations were not significantly (p>0.05) different between the two groups with different fertilization levels. Based on these results, it was concluded that the group with two times of harvesting frequency with conventional fertilization level might be proper for obtaining better forage productivity for Alpine grassland at 800 m altitude.

• Korean Journal of Agricultural and Forest Meteorology
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• v.20 no.4
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• pp.284-295
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• 2018

The safe and late marginal heading dates (SMHD, LMHD), cropping probability, and growth duration of rice were assessed using temperature data in the 27 regions of North Korea. The medians of SMHD and LMHD ranged Jul. 16 and Jul. 27 in Hyesan to Aug. 18 and Aug. 28 in Haeju, respectively, except Changjin, Pungsan, and Samjiyon that did not show any of the SMHD and LMHD. The medians of the days from early marginal transplanting date (EMTD) to heading date ranged 51 days in Hyesan to 109 days in Pyongyang for SMHD and those were delayed by 9~15 days for LMHD, compared to SMHD. Nineteen regions (Kaesong, Haeju, Yongyon, Singye, Sariwon, Nampo, Pyongyang, Anju, Kusong, Sinuiju, Changjon, Wonsan, Hamhung, Pyonggang, Yangdok, Huichon, Supung, Sinpo, Kanggye) and additional four regions (Kimchaek, Chongjin, Sonbong, Chunggang) had the rice cropping probability higher than 80% when analyzed based on the SMHD and LMHD, respectively. The representative SMHD ranged Jul. 24 for Pyonggang to Aug. 12 for Haeju. Compared to the days from EMTD to SMHD, those from EMTD to LMHD were delayed by 9~17 days. When applied SMHD, thirteen regions (Yangdok, Kanggye, Huichon, Supung, Yongyon, Kusong, Anju, Sinuiju, Singye, Pyongyang, Kaesong, Nampo, Sariwon) had the appropriate range of cumulative temperature during grain filling (CT) for grain yield and quality. Sinpo, Hamhung, Pyonggang, Wonsan, Changjon, and Haeju had the CT higher than $1,300^{\circ}C$. It is supposed that rice cropping could be extended to the regions where LMHD-applied cropping probability was higher than 80%. Delaying the heading date than SMHD could be also considered in the regions where the days to SMHD is small but CT is large.

• The Journal of Engineering Geology
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• v.32 no.4
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• pp.697-723
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• 2022

Data-driven models to predict groundwater levels 30 days in advance were developed for 12 groundwater monitoring stations in the middle-Jeju watershed, Jeju Island. Stacked long short-term memory (stacked-LSTM), a deep learning technique suitable for time series forecasting, was used for model development. Daily time series data from 2001 to 2022 for precipitation, groundwater usage amount, and groundwater level were considered. Various models were proposed that used different combinations of the input data types and varying lengths of previous time series data for each input variable. A general procedure for deep-learning-based model development is suggested based on consideration of the comparative validation results of the tested models. A model using precipitation, groundwater usage amount, and previous groundwater level data as input variables outperformed any model neglecting one or more of these data categories. Using extended sequences of these past data improved the predictions, possibly owing to the long delay time between precipitation and groundwater recharge, which results from the deep groundwater level in Jeju Island. However, limiting the range of considered groundwater usage data that significantly affected the groundwater level fluctuation (rather than using all the groundwater usage data) improved the performance of the predictive model. The developed models can predict the future groundwater level based on the current amount of precipitation and groundwater use. Therefore, the models provide information on the soundness of the aquifer system, which will help to prepare management plans to maintain appropriate groundwater quantities.