• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.989-996
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• 2017

The proposed directional pencil beam antenna consists of a waveguide feeder with bended elliptical conductor plate feed and a parabolic curved reflector. Two rectangular apertures located at the broad wall near the end of the feed waveguide inserted from behind the reflector are located at the focus of the reflector and emit electromagnetic energy with bended elliptical conductor plate. This plate is designed to reflect electromagnetic energy primarily and to face the main reflector. The two rectangular apertures located at the waveguide end have inwardly protruding tabs for impedance matching of the antenna system, the shape of the tabs is a truncated oval. The proposed parabolic reflector antenna has a diameter of 400 mm and a focal length of 134.23 mm. The antenna gain is 33.68 dBi at the center frequency of 16.5 GHz, the beam width is $3.3^{\circ}$ and the reflection loss is -15 dB. Using the HFSS-IE, simulation results are performed to validate the proposed antennas.

• Journal of Physiology & Pathology in Korean Medicine
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• v.20 no.5
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• pp.1187-1195
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• 2006

Panax notoginseng exhibit several beneficial effects including anti-oxidant effects. P. notoginseng is used as a therapeutic agent to stop haemorrhages and a tonic to promoted health in Korean and Chinese medicine. The pharmacokinetic profiles of the main P. notoginseng are still not accurately investigated. The exact mechanism of the anti-oxidant activitys of water extracts of P. notoginseng, however, has not been determined. in present study, I examined the effects of water extracts of P. notoginseng on high cholesterol diet atherosclerosis-induced rats in serum and abdominal aorta. A total of 3-week old 9 male rats of Sprague-Dawley were divided into 3 groups and fed with the basal diet (normal group), high cholesterol diet (atherosclerosis induced group) for 8 weeks, high cholesterol diet supplemented with water extracts of P. notoginseng (P. notoginseng group) for 4 weeks. And rats were sacrificed, serum lipid level, abodominal aortic anti-oxidant activities and lipid peroxide were measured. These results indicated that serum total cholesterl, LDL-cholesterol, triglycerides concentration significently lowered in P. notoginseng group than high cholesterol diet group. But HDL-cholesterol concentraion significently higher in P. notoginseng group than high cholesterol feed group. And abdominal aortic xanthine oxidase activity was significantly reduced by dietary water extracts of P. notoginseng supplementation (p<0.05) Also abdominal aortic superoxide dismutase, catalase, glutathione peroxidase activities were significantly increased by dietary water extracts of P. notoginseng supplementation (p<0.05) Especially, abdominal aortic level of lipid peroxide tended to increase in high cholesterol feed group, but water extract of P. notoginseng intake reduced the value (p<0.05).

• Journal of Korean Society of Water and Wastewater
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• v.35 no.4
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• pp.285-292
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• 2021

Osmotic power is to produce electric power by using the chemical potential of two flows with the difference of salinity. Water permeates through a semipermeable membrane from a low concentration feed solution to a high concentration draw solution due to osmotic pressure. In a pressure retarded osmosis (PRO) process, river water and wastewater are commonly used as low salinity feed solution, whereas seawater and brine from the SWRO plant are employed as draw solution. During the PRO process using wastewater effluent as feed solution, PRO membrane fouling is usually caused by the convective or diffusive transport of PRO which is the most critical step of PRO membrane in order to prevent membrane fouling. The main objective of this study is to assess the PRO membrane fouling reduction by pretreatment to remove organic matter using coagulation-UF membrane process. The experimental results obtained from the pretreatment test showed that the optimum ferric chloride and PAC dosage for removal of organic matter applied for the coagulation and adsorption process was 50 mg/L as FeCl₃ (optimum pH 5.5). Coagulation-UF pretreatment process was higher removal efficiency of organic matter, as also resulting in the substantial improvement of water flux of PRO membrane.

• Journal of Animal Science and Technology
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• v.63 no.6
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• pp.1275-1285
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• 2021

The objective of the present experiment was to investigate the effect of dietary palm kernel meal (PKM) and β-xylanase supplementation on productive performance, egg quality, fatty liver incidence, and excreta characteristics in laying hens. A total of 320 Hy-Line Brown laying hens (33 weeks of age) were allotted to 1 of 4 treatments with 8 replicates in a feeding trial. Each replicate consisted of 10 consecutive cages with 1 hen per cage. The corn-soybean meal-based control diet was prepared. Additional diet was prepared by including 10% of PKM in the control diet with a partial replacement of corn, soybean meal, and animal fat. In addition, 0.025% β-xylanase was supplemented at the expense of celite to those 2 diets to produce 4 treatment diets in a 2 × 2 factorial arrangement. All hens were provided the diet and water ad libitum for 8 weeks. Results indicated no significant interactions between inclusion of dietary PKM and β-xylanase for all measurements; therefore, the main effects were mainly discussed. Hens fed diets containing 10% PKM had greater (p < 0.05) feed intake and yolk color than those fed diets containing no PKM. However, dietary PKM did not influence fatty liver incidence and excreta characteristics. Dietary β-xylanase supplementation had no effects on all measurements, regardless of inclusion of PKM. In conclusion, PKM can be a potential feed ingredient for laying hens at the inclusion of 10% in the diet. It appears that dietary β-xylanase used in the current experiment has little effect on layer productivity, regardless of inclusion of 10% PKM in the diet.

• Journal of agriculture & life science
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• v.52 no.6
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• pp.61-72
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• 2018

The aim of this present study was to investigate the impact of different seeding rate and nitrogen fertilizing levels on the seed yield and feed value of oats(Avena sativa L.) grown in Gyeongbuk area for two years. The experiment was arranged in split plot design with 3 main plots(100, 130 and 160 kg of seed/ha) and 4 subplots(0, 50, 70 and 90 kg N/ha), with 3 replicates. Heading, flowering, and maturing dates of oats sown in spring 2017, delayed by two days compared to that of spring 2016, and the plant height of spring 2017 were significantly shorter than that of spring 2016(18.1 ~ 23.4 cm). In addition, the highest number of stems and number of panicles according to different seeding rate and nitrogen fertilizing levels were achieved with the seeding rate of 160 kg/ha and 90 kg of N/ha in 2016 and 2017, respectively. In case of seed yield as affected by different seeding rate, the highest seed yield was achieved with a seeding rate of 130 kg/ha(p<0.05), and based on nitrogen fertilizing levels, the highest yield was obtained in 50 kg of N/ha compared to others. The crude fiber(CF), neutral detergent fiber(NDF) and total digestible nutrients(TDN) of oats cultivated and harvested in spring 2016 and 2017 according to different sowing rate were the highest in the seeding rate of 130 kg/ha. The crude protein(CP) content and total digestible nutrients(TDN) of 2016-2017 as influenced by nitrogen fertilizer levels were the highest in the nitrogen fertilizer level of 90 and 50 kg N/ha, respectively. In conclusion, the proper seeding rate and the optimal nitrogen fertilizing level in Gyeongju, Gyeongbuk province were considered to be the most appropriate in 130 kg/ha and 50 kg of N/ha, respectively.

• Korean Journal of Veterinary Service
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• v.42 no.2
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• pp.67-71
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• 2019

A variety of livestock feed resources were used in Korean dairy farm due to a lack of the endemic feed. However, there is inadequate real farm data to support farmers' decisions on the choice of options. The main objective of this study was to evaluate the nutritional value of total mixed ration (TMR) as well as the metabolic diseases status in Korean dairy farms. TMR samples were collected from nine feed companies and eight selected self-formulated by the dairy farms. The nutrient contents were examined by AOAC methods. The frequency of metabolic diseases such as ketosis and hypocalcemia were surveyed. The average moisture content was 36.2% although the min. and max. value were varied from 21.7% and 50.6% among farms. The mean${\pm}$standard deviation of crude fiber (CF), crude ash (CA), ether extract (EE), and crude protein (CP) were $21.4{\pm}2.5$, $4.6{\pm}0.4$, $3.2{\pm}0.5$ and $9.8{\pm}1.7$, respectively. However, the average ADF and NDF was $17.3{\pm}3.7$ and $31.0{\pm}5.7$, respectively. The compositions of TMR were varied significantly among the dairy farms. The frequency of clinical Ketosis (CK), subclinical ketosis (SCK) and hypocalcemia were higher in early lactation period with 4.5%, 11.0% and 3.0%, respectively. Also, the frequency of SCK was higher than CK and hypocalcemia throughout the lactation. Periodic TMR nutrient analysis based on herd production or physiology change would maximize the effects of TMR feeding. Furthermore, the study results would be useful to the farm practitioner and producer for their farm management.

• Animal Bioscience
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• v.35 no.8
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• pp.1205-1214
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• 2022

Objective: Spent ginger is a byproduct of juice extraction from the rhizome of ginger (Zingiber officinale). Despite its nutritional value, it is difficult to preserve or further process and thus is often wasted. This study uses spent ginger as a substrate for fermentation and cultivates spent ginger yeast cultures (SGYCs) that are then added to the feed of laying hens. The effects of SGYCs on production performance, egg quality, serum composition, and intestinal microbiota of laying hens were investigated. Methods: Eighty 60-week-old Hy-Line Brown hens were separated into 5 experimental groups with 4 replicates per group (4 hens per cage, 4 cages per replicate). The control group was fed a basal diet while experimental groups were also given SGYCs at the levels of 5, 10, 20, and 40 g/kg for 6 weeks. Results: The addition of SGYCs significantly increased the laying rate and nutrient digestibility, decreased feed conversion ratio, and enhanced the color of egg yolks (p<0.05). No changes were observed in activity levels of alanine aminotransferase and aspartate aminotransferase in the serum (p>0.05), but the activities of superoxide dismutase, glutathione peroxidase, and peroxidase all significantly increased, and contents of malondialdehyde were significantly reduced (p<0.05). In addition, changes in the relative abundance of Firmicutes and Bacteroidetes might be the main factor contributing to the significant increase in the apparent digestibility of crude protein and crude fat in laying hens (p<0.05). Conclusion: The current evidence shows that dietary supplementation of SGYCs to the feed of laying hens can improve laying rates, enhance antioxidative defenses, and influence dominant intestinal bacteria.

• Journal of Animal Science and Technology
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• v.59 no.7
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• pp.19.1-19.10
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• 2017

Background: To reduce use of main feed ingredient like corn, soy bean meal (SBM) and wheat, alternative ingredients has been studied like copra meal (CM). Production amount of CM which has been high makes CM to be an alternative feed stuff. However, low digestibility on AA and low energy content by high fiber content can be an obstacle for using CM. This experiment was conducted to evaluate the effects of CM supplementation with ${\beta}$-mannanase on growth performance, blood profile, nutrient digestibility, pork quality and economic analysis in growing-finishing pigs. Methods: A total of 100 growing pigs ([Yorkshire ${\times}$ Landrace] ${\times}$ Duroc) averaging $31.22{\pm}2.04kg$ body weight were allotted to 5 different treatments by weight and sex in a randomized complete block (RCB) design in 5 replicate with 4 pigs per pen. Treatments were 1) Control (corn-SBM based diet + 0.1% of ${\beta}$-mannanase (800 IU)), 2) CM10 (10% copra meal + 0.1% ${\beta}$-mannanase (800 IU)), 3) CM15 (15% copra meal + 0.1% ${\beta}$-mannanase (800 IU)), 4) CM20 (20% copra meal + 0.1% ${\beta}$-mannanase (800 IU)) and 5) CM25 (25% copra meal + 0.1% ${\beta}$-mannanase (800 IU)). Four phase feeding program was used: growing I (week 1-3), growing II (week 4-6), finishing I (week 7-9) and finishing II (week 10-12). Results: In growth performance, there was no significant difference among treatments during whole experimental period. In growingI phase, G:F ratio tended to increase when CM was increased (P = 0.05), but ADG and ADFI tended to decrease in finishingII phase (linear, P = 0.08). Also, increasing CM reduced ADG (linear, P = 0.02) and feed efficiency (linear, P = 0.08) during the whole finishing period. In blood profiles, BUN was linearly increased as CM increased (linear, P = 0.02) at growingII period. In digestibility trial, there was no significant difference in dry matter, crude fat, crude ash and nitrogen digestibility. However, crude protein digestibility was decreased linearly (linear, P = 0.02). In economic analysis, feed cost per weight gain and total feed cost per pig were reduced in overall period when CM was provided by 25% (linear, P = 0.02). Conclusion: CM with 0.1% of ${\beta}$-mannanase (800 IU) could be supplemented instead of corn and SBM up to 25% without detrimental effects on growth performance and pork quality of growing-finishing pigs.

• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.245-257
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• 2001

Localization of livestock facilities leads to concentration of livestock wastes and subsequent leakage of pollutants into the environment, resulting in public concern about their effects. Nitrogen (N) and phosphorus (P) are the most harmful components of animal manure, but odor from the manure itself and the livestock facilities is also a problem. Improving the nutrient efficiency of the livestock helps to decrease excretion of these environmental contaminants. Pigs and chickens are the main experimental models used in studies to improve nutrient efficiency. Addition of feed supplements and modifying feeding systems to improve nutrient efficiency can result in significant decrease in the N, P, odor and dry matter (DM) weight of manure. Examples of these methods include the following. 1) Addition of synthetic amino acids and reducing protein contents resulted N reductions of 10∼27% in broilers, 18∼35% in chicks and layers, 19∼62% in pigs, and a 9∼43% reduction in odor in pigs. 2) Enzyme supplementation resulted in a 12∼15% reduction in DM weight in broiler manure. 3) Phvtase supplementation resulted in P reductions of 25∼35% in chickens and 20∼60% in pigs. 4) Use of growth promoting substances resulted in a 5∼30% reduction in N and a 53∼56% reduction in odor of pigs. 5) Formulating diets closer to requirements (diet modification) reduced N and P by 10∼15% each in chickens and pigs, and odor by 28∼ 79% in pigs. 6) Phase feeding reduced N and P excretion by chicken and pigs from 10∼33% and 10∼13% each, as well as odor in growing and finishing pigs by 49∼79%. 7) Use of highly digestible raw materials in feed reduced N and P excretion by 5% in chickens and pigs.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.73-73
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• 2017

To set an optimal harvest time of main 7 whole crop silage rice cultivars, Nokyang(Ny), Mogwoo(Mw), Mogyang(My), Jungmo1029(Jm1029), Jungmo1038(Jm1038), Nokwoo(Nw) and Yeongwoo(Yw), based on feed value, we analyzed their feed values such as percent crude protein(CP), crude fat(CF), crude ash(CA), neutral detergent fiber(NDF), acid detergent fiber(ADF) and lignin. It was evaluated every 10 days from heading to 40 days after heading(DAH). Total digestible nutrient(TDN) and relative feed value(RFV) was also calculated from ADF and NDF. As results, CP was generally in decline as increasing DAH in Ny, My, Jm1029, Jm1038 and Yw and decreased to 20 DAH in Mw, decreased after increasing to 30 days in Nw. The CP content of Ny was relatively the highest ranged from 5.3% to 10.1% and Mw the lowest 4.5% to 5.2%, compared to others. CF content tend to decrease as DAH increase in Ny, My and Nw and decreased after increasing to 30 days Jm1029, increased after decreasing to 20 days Jm1038 but was not shown distinct trend of increase or decrease in Mw. Especially, that of Yw's CF gradually increased as harvest time late but relative content the lowest from 1.46% to 2.29% among 7 cultivars. The CA content of Ny, My, Jm1029 and Jm1038 approximately decreased as DAH increased and that of Mw was similar to others after heading, Nw decreased after 10 days and Yw increased after flowering. In all 7 cultivars, NDF and ADF had a tendency to decrease as days accumulated, in particular, Yw was the lowest on 30 DAH and so the content of Yw's TDN the highest(71.5%), while the lowest(67.2%) in Nw. For lignin, particularly, Mw tend to be in decline as DAH increase and was the lowest ranged from 1.34% to 1.87%. ADF analyses allows for the evaluation of in vivo digestible dry matter(DDM) and energy availability and NDF analyses provides the best indication of dry matter intake(DMI). Ultimately, the two factors can be combined to derive RFV for forage. RFV in general increased as DAH increased in all cultivars and was in order, Yw>My>Ny> Jm1038>Mw>Jm1029>Nw on 30 DAH. Taken together when these results, despite a slight increase of TDN after 30 DAH except Yw, considering forage yield potential, digestibility of grains and gradual decrease of CP and CF, the yellow ripe stage, about 30 DAH, was appropriate to harvest whole crop rice for silage use.