• Journal of Drive and Control
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• v.19 no.1
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• pp.16-25
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• 2022

The purpose of this study was to calculate and analyze the engine load factor of major agricultural operations using a 78 kW class agricultural tractor for estimating the emission of air pollutants and greenhouse. Engine load data were collected using controller area network (CAN) communication. Main agricultural operations were selected as plow tillage (PT), rotary tillage (RT), baler operation (BO), loader operation (LO), driving on soil (DS), and driving on concrete (DC). The engine power was calculated using the measured engine load data. A weight factor was applied to load factor for considering usage ratio according to agricultural operations. Weight factors for different agricultural operations were calculated to be 27.4%, 32.9%, 17.5%, 7.7%, 4.5%, and 10.0% for PT, RT, BO, LO, DS, and DC, respectively. As a result of the field test, load factors were 0.74, 0.93, 0.41, 0.23, 0.27, and 0.21 for PT, RT, BO, LO, DS, and DC, respectively. The engine load factor was the highest for RT. Finally, as a result of applying the weight factor for usage ratio of agricultural operations, the integrated engine load factor was estimated to be 0.63, which was about 1.31 times higher than the conventional applied load factor of 0.48. In future studies, we plan to analyze the engine load factor by considering various horsepower and working conditions of the tractor.

• Korean Journal of Agricultural Science
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• v.48 no.4
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• pp.1015-1026
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• 2021

The objective of this study was to determine amino acid and protein contents of brown and milled non-glutinous rice of 13 cultivars in Korea. Protein contents of MRs (milled rices) were in order of Haepum (7.27%) > Hanareum No. 4 (7.14%) > Odae (6.84%). Protein contents of BRs (brown rices) were in order of Haepum (7.68%) > Odae (7.63%) > Hanareum No. 4 (7.60%). The amino acid content was the highest in Haepum (MR 5.76%, BR 6.49%), followed by Haedeul (MR 5.71%, BR 6.30%), and Odae (MR 5.63%, BR 6.29%). The essential amino acid contents of non-glutinous rices were in order of Haepum (MR 2.34%, BR 2.57%) > Haedeul (MR 2.31%, BR 2.48%) > Odae (MR 2.20%, BR 2.56%). The contents of amino acid and protein in BRs were considerably higher than those in MRs. Protein and most of amino acid contents were higher in Haepum than the other cultivars. The certificated reference material (CRM) 1849a (infant/adults nutritional formular) from National Institute of Standard and Technology (NIST) was used as the test sample to determine the precision and accuracy of the analytical method. The regression analyses revealed good correlations (correlation coefficient), greater than 0.99. The recovery values of the amino acids ranged from 93.17 to 99.59%. The limit of detection (LODs) ranged from 0.01 - 0.07 mg·100 g^-1 and the limit of quantitation (LOQs) ranged from 0.03 - 0.21 mg·100 g^-1 for all analytes.

• Journal of Animal Science and Technology
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• v.65 no.3
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• pp.588-595
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• 2023

The aim of this study was to investigate the effects of heat stress on milk traits in South Korea using comprehensive data (dairy production and climate). The dataset for this study comprised 1,498,232 test-day records for milk yield, fat- and protein-corrected milk, fat yield, protein yield, milk urea nitrogen (MUN), and somatic cell score (SCS) from 215,276 Holstein cows (primiparous: n = 122,087; multiparous: n = 93,189) in 2,419 South Korean dairy herds. Data were collected from July 2017 to April 2020 through the Dairy Cattle Improvement Program, and merged with meteorological data from 600 automatic weather stations through the Korea Meteorological Administration. The segmented regression model was used to estimate the effects of the temperature-humidity index (THI) on milk traits and elucidate the break point (BP) of the THI. To acquire the least-squares mean of milk traits, the generalized linear model was applied using fixed effects (region, calving year, calving month, parity, days in milk, and THI). For all parameters, the BP of THI was observed; in particular, milk production parameters dramatically decreased after a specific BP of THI (p < 0.05). In contrast, MUN and SCS drastically increased when THI exceeded BP in all cows (p < 0.05) and primiparous cows (p < 0.05), respectively. Dairy cows in South Korea exhibited negative effects on milk traits (decrease in milk performance, increase in MUN, and SCS) when the THI exceeded 70; therefore, detailed feeding management is required to prevent heat stress in dairy cows.

• Korean Journal of Food Science and Technology
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• v.46 no.1
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• pp.100-107
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• 2014

We evaluated preventive effects of Suaeda japonica (SJ) and Spergularia marina Griseb (SMG) on the insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. The 10-week old OLETF rats were fed diets containing 3% (w/w) SJ and SMG for 18 weeks. Fasting blood glucose levels in SJ and SMG groups, measured using the oral glucose tolerance test, were lower than that of the control rats. The SMG group showed significantly lower levels of insulin, glycated hemoglobin, triglyceride, and total cholesterol than the control group. In addition, these levels were relatively lower in the SJ group than those in the control rats. The SJ and SMG groups had relatively lower protein levels of nuclear factor-kappa B (NF-${\kappa}B$) p65 in adipose tissue and serine phosphorylated insulin receptor substrate 1 (IRS-1) in skeletal muscle than the control group. These results suggest that SJ and SMG prevent insulin resistance and SMG in particular reduces blood triglyceride and total cholesterol levels.

• Journal of Life Science
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• v.23 no.5
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• pp.698-702
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• 2013

It is known that black sticky rice with giant embryo (BSRGB, Milyang 263) and giant embryo rice (GER) contains higher levels of GABA than rice. Therefore, feeding BSRGB, GER, or rice freely to C57BL/6 mice with two-hour alcohol intake for 16 days was investigated. For two-hour alcohol intake, a repeated measure ANOVA (three treatment groups repeated across 16 days; 8 two-day blocks) yielded a significant group by block interaction (df=16, F=3.109, p=0.004). The independent t-test showed that significant suppression of two-hour alcohol intake was observed when subjects were administered with BSRGB, compared with the rice alone across all the two-day blocks (p<0.05). The paired t-test revealed that a significant suppression of two-hour alcohol intake was observed starting 4 to 16 days after freely feeding with BSRGB compared to before feeding. However, there is no significant difference in the two-hour alcohol intake observed between the before and after administration of rice. A repeated measure ANOVA revealed no significant group by block interaction for 22-hour water intake and body weight. However, a repeated measure ANOVA revealed a significant grouping by block interaction for food intake. These results indicate a change of two-hour alcohol intake is presumably caused by GABA, which is found in higher levels in BSRGB than in rice.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.252-259
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• 2013

BACKGROUND: Salt accumulation in coastal reclaimed soil can decrease plant growth and productivity, which could lead to considerable variation of methane($CH_4$) emission in a rice paddy. The objective of this study was to evaluate the effect of salt concentration on $CH_4$ emission in a coastal reclaimed soil. METHODS AND RESULTS: The effect of salt concentration on $CH_4$ emission and rice growth characteristics was studied by pot test, which packed by reclaimed paddy soils collected from Galsa, Hadong, Gyeongnam province. Electrical conductivity(EC) of each treatment was controlled by 0.98, 2.25, 5.05 and 9.48 dS/m and $CH_4$ emission was characterized a week interval by closed chamber method during rice cultivation. The $CH_4$ emission rate was significantly decreased with increase of salt accumulation, but total $CH_4$ flux in EC 5.50 dS/m treatment was lower than those of EC 9.48 dS/m treatment. It seems because of higher content of water soluble $SO{_4}^{2-}$ in EC 5.50 dS/m treatment than those of EC 9.48 dS/m treatment. Rice growth and grain yield were significantly decreased with increase of salt accumulation. Soil properties, especially EC and pH were negatively correlated with $CH_4$ flux, while rice growth characteristics like plant height and tiller number show significantly positive correlation with $CH_4$ flux. CONCLUSION(S): Conclusively, salt accumulation significantly decreased $CH_4$ flux in a rice paddy, which could be useful information for evaluating $CH_4$ flux in reclaimed area in Korea.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.282-289
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• 2014

BACKGROUND: Methane($CH_4$) is considered as the secondmost potent greenhouse gas after carbon dioxide ($CO_2$). Methanogenesis is an enzyme-mediated multi-step process by methanogens. In the penultimate step, methylated Co-M is reduced by methyl Co-M reductase (MCR) to $CH_4$ involving a nickel-containing cofactor F430. The activity of MCR enzyme is dependent on the F430 and therefore, the bioavailability of Ni to methanogens is expected to influence MCR activity and $CH_4$ production in soil. In this study, different doses of EDTA(Ethylene Diamine Tetraacetic Acid) were applied in flooded soils to evaluate their suppression effect on methane production by chelating Ni of methanogenesis cofactor. METHODS AND RESULTS: EDTA was selected as chelating agents and added into wetland and rice paddy soil at the rates of 0, 25, 50, 75, and $100mmol\;kg^{-1}$ before 4-weeks incubation test. During the incubation, cumulative $CH_4$ production patterns were characterized. At the end of the experiment, soil samples were removed from their jars to analyze total soil Ni and water-soluble Ni content and methanogen abundance. Methane production from 100 mmol application decreased by 55 and 78% in both soils compared to that from 0 mmol. With increasing application rate of EDTA in both soils, water-soluble Ni concentration significantly increased, but total soil Ni and methanogen activities showed negative relationship during incubation test. CONCLUSION: The decrease in methane production with EDTA application was caused by chelating Ni of coenzyme F430 and inhibiting methanogenesis by methyl coenzyme M reductase. Consequently, EDTA application decreased uptake of Ni into methanogen, subsequently inhibited methanogen activities and reduced methane production in flooded soils.

• Research in Plant Disease
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• v.24 no.1
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• pp.41-51
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• 2018

Since fire blight disease on apple and pear was produced in Korea in 2015, there were no registered chemicals to control against this disease. Instead, several antibacterial chemicals that were registered for other bacterial diseases such as soft rot and bacterial spot have been authorized by Rural Development Administration (RDA). However, these chemicals are not tested efficacy for fire blight disease except damage by those treatments on apple and pear in Korea. Thus, we evaluated efficiency using in vitro and in planta assays of antibacterial chemicals such as antibiotics and copper compounds including kasugamycin, oxytetracycline, oxolinic acid and streptomycin, and copper hydroxide, copper sulfate, oxine copper and tribasic copper sulfate, respectively. We also tested two kinds of biological agents. As expected, significant antibacterial effect was observed in vitro test of both antibiotics and copper-based chemicals. In planta test based on disease severity including ooze and water-soaked formation on immature pears, bacterial populations on blooms, and blight lesion formation in artificially inoculated shoots, kasugamycin, oxytetracycline and streptomycin have been shown the most efficiency among tested antibiotics. Four copper-based chemicals tested in this study, control effects are little bit lower than agricultural antibiotics but they seem to be available to use in terms of winter season. Biocontrol agents were also shown possibility to treat in eco-friendly farms. In addition, there are no antibiotic resistance genes in Korean isolates against antibiotics, which were selected for suppression of fire blight in this study.

• Korean Journal of Poultry Science
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• v.31 no.3
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• pp.193-198
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• 2004

This study was conducted for improvement of meat quality in broiler chcikens. Birds were fed basal diet(control), ferritin, illite, betafin, or wood vinegar counting broiler feed according as broiler growth stage. Birds fed with basal diet, which was distributed under the best environmental condition, were more weight gain than other groups reared under same environmental condition. In the mean weight gain, the ferritin-group showed the highest and the illite-group showed the lowest among the feed additive groups; therefore, the effect of feed requirement change in odor reduction in illite and methyl saving of betafin was lower than those of other feed additives along to pass rear time. Meat quality was appraised by National Livestock Research Institute of RDA. Except the control-group, that had the best feed conversion ratio, the cooking loss of the illite-group was the biggest among groups although the illite-group chickens had a good water hold capacity. Therefore, illite is not good for making merchandise by reason that group chickens get reduction carcass weight after slaughter. On the other hand, the ferritin-group got the highest point of shear stress, cooking loss, and crude fat level. That group showed the best appraise in both breast and leg of sensory test in company and also feed conversion ratio was the highest among feed additive groups. As a result, the ferritin-group might use for making new merchandise among the feed additive groups.

• Journal of Korean Home Economics Education Association
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• v.18 no.4 s.42
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• pp.207-216
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• 2006

The purpose of this study was to investigate the body composition and the nutrient intakes of the physical-education high school male athletics and high school male students in Daegu Kyungpook. The study was performed by 122 physical-education high school male students and 78 high school male students. Statistical data analysis was completed by using the SPSS 12.0 program. They were also analyzed by student's t-test at p<0.05. The results were summarized as follows. (1) Chest circumference in athletic group(AG) was significantly higher than in nonathletic group(NG). Hip circumference in nonathletic group(NG) was significantly higher than in athletic group(AG)(p<0.01). Skinfold thickness of triceps, biceps and subscapular in nonathletic group(NG) were thicker than that of athletic group(AG) significantly(p<0.001). Percent of body fat and body fat mass in nonathletic group(NG) were higher than that of athletic group(AG) significantly(p<0.001). Lean body mass in athletic group(AG) was higher than that of nonathletic group(NG) significantly(p<0.001). (2) Athletic group(AG) was significantly higher than nonathletic group(NG) in energy nutrient intakes and vitamin, mineral and other nutrient intakes except Na, vitamin B6, vitamin E(p<0.001). Athletic group(AG) had more intakes than RDA for all nutrient except calcuim. (3) Nonathletic group(NG) was significantly higher than Athletic group(AG) in total nutrition knowledge scores.