• Journal of the Institute of Electronics Engineers of Korea TC
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• v.39 no.2
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• pp.92-100
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• 2002

The 16-port feed waveguide array with inductive walls analyzed by Galerkin's method of moments are proposed for the DBS reception system mounted on vehicle. First of all, in order to verify the validity of electromagnetic analysis and design for a $\pi$-junction feed waveguide, it is designed and fabricated at DBS band. The measurement results of a $\pi$-junction feed waveguide agree well with the theoretical ones. Based on this design method, an array design for WR-90 standard waveguide is conducted. Since the width of a $\pi$-junction feed WR-90 standard waveguide is larger than a guided wave length in an array design, the difference of amplitude and phase of 8-port array are calculated 2.3 dB and 62 degrees, respectively. The bandwidth with return loss of -20 dB below is about 220 MHz and it doesn't satisfy DBS band. To solve this problem, we propose a novel design that the width of a $\pi$-junction feed waveguide equals to a guided wave length. By the proposed novel design for 8-port feed waveguide array, the difference of amplitude and phase are decreased 1 dB and 13 degrees, respectively. The broad bandwidth of 700 MHz is also realized. The size of 16-port waveguide away compared with WR-90 array is reduced about 10 cm. The measured antenna gain for the fabricated 16-port feed waveguide array is observed 24 dBi above at DBS band.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.569-576
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• 2012

Two experiments were conducted to investigate the potential for Forsythia suspensa extract (FSE) to substitute for antibiotic in broiler chicken. First, a well-diffusion assay procedure and a 2-fold dilution method were used to determine the bacteriostatic activity of FSE on Escherichia coli K88, staphylococcus aureus, and salmonella was assayed. An inhibitory effect of FSE was observed on the growth of these bacteria. This effect seems to be dose depended, which disappeared after 25.00, 12.50, 1.56 mg/ml. Second, a 42-d trial with 252 broiler chickens (d 1, $38.7{\pm}1.1$ g BW) was conducted to evaluate the effect of dietary supplementation of FSE in broiler chicken. The feeding program consisted of a starter diet from d 1 to 21 and a finisher diet from d 22 to 42. Dietary treatments included were: i) NC: negative control fed a corn-soybean meal based diet; ii) PC: positive control group fed based diet with chlortetracycline; and iii) FC: a test group fed with 100 mg FSE/kg diet. In this study growth performance did not differ among treatments during the starter period. However, dietary supplemental chlortetracycline and FSE increased (p<0.05) average daily gain (ADG), average daily feed intake (ADFI) compared with NC during the finisher and overall phase. Apparent digestibility of calcium on d 21, digestibility of energy and calcium on d 42 of FC was greater (p<0.05) than NC. Moreover, cecal Escherichia coli counts for birds from FC were lower (p<0.05) than NC. Dietary FSE supplementation also improved (p<0.05) villus height and villus height to crypt depth ratios in both duodenum and ileum and decreased (p<0.05) crypt depth in the duodenum. Duodenum villus height and villus height to crypt depth ratio in both duodenum and ileum from the FC group were also greater (p<0.05). Serum growth hormone and IGF-1 were not influenced by different treatments. Apparently, FSE has the potential to substitute for antibiotic in broiler chicken.

• Animal Bioscience
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• v.37 no.2
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• pp.274-283
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• 2024

Objective: The aim of the study was to evaluate the physicochemical properties (nutrient composition, pH, water content and activity, sorption properties) and mechanical properties (compression force and energy) of granulated feed mixtures with various inclusion levels of crude fibre concentrates ARBOCEL and VITACEL for broiler chickens, i.e. +0.0% (control group - group C), +0.3%, +0.8%, +1.0%, +1.2%. Methods: The feed mixtures were analyzed for their physicochemical properties (nutrient composition by near-infrared spectroscopy, pH with the use a CP-401 pH meter with an IJ-44C glass electrode, water content was determined with the drying method and activity was determined with the Aqua Lab Series 3, sorption properties was determined with the static method) and mechanical properties (compression force and energy with the use TA-HD plus texture analyzer). The Guggenheim-Anderson-de Boer (GAB) model applied in the study correctly described the sorption properties of the analyzed feed mixtures in terms of water activity. Results: The fibre concentrate type affected the specific surface area of the adsorbent and equilibrium water content in the GAB monolayer (p≤0.05) (significantly statistical). The type and dose of the fibre concentrate influenced the dimensionless C and k parameters of the GAB model related to the properties of the monolayer and multilayers, respectively (p≤0.05). They also affected the pH value of the analyzed feed mixtures (p≤0.05). In addition, crude fibre type influenced water activity (p≤0.05) as well as compression energy (J) and compression force (N) (p≤0.001) (highly significantly statistical) of the feed mixtures. Conclusion: The physicochemical analyses of feed mixtures with various inclusion levels (0.3%, 0.8%, 1.0%, 1.2%) of crude fiber concentrates ARBOCEL or VITACEL demonstrated that both crude fiber types may be used in the feed industry as a feedstuff material to produce starter type mixtures for broiler chickens.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.11
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• pp.1617-1626
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• 2012

The objective of this study was to evaluate the effects of adding essential oils to the diet of weaned pigs on performance, nutrient utilization, immune response and intestinal health. A total of 96 weaning pigs ($8.37{\pm}1.58$ kg) were allotted to one of three dietary treatments. The treatments consisted of an unsupplemented basal diet (negative control, NC) or similar diets supplemented with 0.01% of an essential oil product which contained 18% thymol and cinnamaldehyde (EOD) as well as a diet supplemented with 0.19% of an antibiotic mixture which provided 150 ppm chlortetracycline, 80 ppm colistin sulfate and 50 ppm kitasamycin (positive control, PC). Each treatment was provided to eight pens of pigs with four pigs per pen. Over the entire 35 d experiment, ADG and fecal score were improved (p<0.05) for pigs fed the PC and EOD compared with the NC. Dry matter and crude protein digestibility as well as lymphocyte proliferation for pigs fed the PC and EOD diets were increased significantly compared with NC (p<0.05). IGF-I levels in plasma were significantly increased (p<0.05) in pigs fed the PC diet compared with pigs fed the NC diet. Interleukin-6 concentration was lower (p<0.05) and the tumor necrosis factor-${\alpha}$ level was higher (p<0.05) in the plasma of pigs fed the EOD diet than the NC diet. Plasma total antioxidant capacity level increased (p<0.05) in pigs fed the EOD diet compared with pigs fed the NC. Villus height to crypt depth ratio in the jejunum was greater (p<0.05) in pigs fed the PC and EOD diets than the NC. The numbers of E. coli in the cecum, colon and rectum were reduced (p<0.05) in pigs fed the PC and EOD diets compared with the control. In the colon, the ratio of Lactobacilli to E. coli was increased (p<0.05) in pigs fed the EOD diet compared with NC diet. Total aerobe numbers in the rectum were decreased (p<0.05) in pigs fed the PC and EOD diets compared with the control. Collectively, these results indicate that blends of essential oils could be a candidate for use as an alternative to traditional antibiotics in weaning pig diets.

• Journal of Nutrition and Health
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• v.8 no.2
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• pp.7-13
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• 1975

In the classic point of view, it has well known that the tangle is the mineral source, especially iodide. However, there are few reports that the tangle can be used the high-protein source. With the consideration whether the tangle can be used as a protein source as well as one of the foodstuff or not, this studies is done by animal experiment. The Albino rats to be examined were fed on the basal diet (Table 1) and the others including the polished tangle by weight 2%, 3%, 4% and 5%, as experimental diets, for 4 weeks, respectively. The weight gain(Fig. 1), total amount of diet intake (Fig. 2), total water intake(Fig. 3), feed efficiency ratio (Fig. 4) and protein efficiency ratio (Fig. 5) was measured by each week, respectively. In addition, organ weight (Fig. 6) and blood study (Fig. 7, Fig. 8) was also analyzed at the end of the experiment. As the results of this study, growth rate, that is, weight gain, feed efficiency ratio and protein efficiency ratio in all experimental groups increased more than those of the control group. Moreover, it was also found that weight gain, feed efficiency ratio, protein efficiency ratio by feeding on the 2 percent tangle group was higher than the corresponding values of all experimental groups. However, feed intake and total water gain were the most by feeding on the 5% tangle group. This result may be interpreted to show that the total content of sodium includes more than enough in the feed intakes. To obtain further information concerning the effect of the tangle-dietary conditions on the growth rate of Albino rats, it was measured the organ weight. In the adrenal and spleen, the total weight by feeding on the all experimental groups were decreased more than that in the case of the control group. In the other hand, in the liver the weight by feeding on the high concentration groups (4%, 5% tangle diets) were not higher than the control group, while in the case of the low concentration groups (2%, 3% tangle diets) were higher than that of the control group. When it was observed the blood components, total protein, hemoglobin, sodium, potassium, white blood cell and red blood cell of rats, the content of white blood cell by feeding on all experimental groups were lower than that by feeding on the control group, but it was also clear that in the other components except white blood cell in blood the contents by feeding on all experimental groups were similar to that in the case of the control groups. However, in the 5% tangle group, the content of sodium was the lowest of all experimental groups, where as the content of potassium was the highest of all experimental groups.

• Animal Bioscience
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• v.34 no.10
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• pp.1607-1615
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• 2021

Objective: Chaya (Cnidoscolus aconitifolius) leaf has been found to be an important source of protein, vitamins, minerals, as well as phytonutrients. The present study aimed to evaluate the effect of Chaya leaf pellet (CHYP) with various level of crude protein (CP) in the concentrate on rumen fermentation characteristics and nutrient degradability in in vitro gas production technique. Methods: In an in vitro rumen fermentation study the dietary treatments were arranged according to a 3×5 factorial arrangement in a completely randomized design, consisting of Factor A: three levels of CP of concentrate mixtures (14%, 16%, and 18% CP, respectively) and Factor B: five levels of CHYP supplementation (at 0%, 2%, 4%, 6%, and 8% of dry matter substrates). Results: The gas production kinetics, fraction (a) and fraction (b) were lower (p<0.05) with an increasing CHYP addition. Additionally, the fraction (a+b) was found to yield a significant interaction (p<0.05) while the fraction (c) was not impacted by CHYP addition. However, in vitro DM degradability was enhanced and interactive (p<0.05), using 16% CP of concentrate with 6% and 8% CHYP, when compared with 18% CP in the non-addition. Additionally, the treatment with higher CP of the concentrate was higher in NH₃-N concentration (p<0.001) and by CHYP supplementation group (p<0.05). Nevertheless, protozoal counts in the rumen were remarkably decreased (p<0.05) with increasing level of CHYP supplementation. Furthermore, rumen C₂ concentration was lower (p<0.05) in the treatments with CHYP supplementation, while C₃ was significantly increased and interactive (p<0.05) between levels of CP and CHYP supplementation especially at 8% CHYP supplementation. Conclusion: Based on this study, the results revealed CHYP as a promising feed supplement to enhance rumen fermentation and to mitigate methane production. However, in vivo feeding experiments should be subsequently conducted to elucidate the effect of CHYP supplementation on rumen fermentation, as well as ruminant production efficiency.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.270-275
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• 2022

Livestock production costs are heavily influenced by the cost of feed, The use of domestically grown forages is more desirable for livestock feed production. As part of this study, triticale, which is an extremely palatable and easily cultivable crop in Korea, was used to produce low moisture silage bales with lactic acid bacteria (LAB) and then stored for different periods. We examined the nutrient content of silage, such as crude protein (CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF), as well as their organic acids, including lactic acid, acetic acid, butyric acid, at different storage periods. The nutrient content of silages, such as crude protein, ADF, and NDF, did not change significantly throughout storage periods. Organic acid data indicated that lactic acid concentrations increased with increasing moisture contents and storage periods up to nine months. However, further extending storage to 12 months resulted in a reduction in the lactic acid content of all silages as well as an increase in their pH. Based on the present results, it suggested that the production of low moisture silage with the LAB may be able to preserve and maintain its quality without altering its nutritional composition. Also, the lactate content of the silage remained significant for at least nine months.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.723-738
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• 2011

Contamination of agricultural crops by mycotoxins results in significant economic losses for grain producers and, when consumed, it can cause reduced growth and health in a wide range of animal species. Hundreds of mycotoxin producing molds exist, however each has a different frequency and pattern of occurrence, as well as differences in the severity of the diseases (mycotoxicoses) they cause. Among the mycotoxins considered to be major contaminates are aflatoxin, deoxynivalenol, fumonisin, ochratoxin, and zearalenone. Although a multitude of species can be harmed by consumption of these mycotoxins, swine appear to be the most commonly affected commodity species. The swine industry can thus experience great losses due to the presence of mycotoxin contamination in feeds. Subsequently, recognition and prevention of mycotoxicoses is extremely important and dependent on adequate grain sampling and analysis methods pre-harvest, as well as effective strategies post-harvest to reduce consumption by animals. The aim of this review is to provide an overview of the major mycotoxin contaminants in grains, to describe methods of analysis and prevention to reduce mycotoxicoses in swine and other animals, and finally to discuss how mycotoxins directly affect swine production.

• Journal of the Korean Solar Energy Society
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• v.37 no.1
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• pp.59-69
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• 2017

In 2012, Korea introduced a Renewable Portfolio Standard (RPS) scheme, replacing the Feed-in Tariff (FIT) scheme as a market support policy of renewable energy in the electricity market. RPS is to allocate obligatory quota of renewable energy sources for electricity suppliers, whereas FIT is to guarantee high prices for electricity from renewable energy sources. This study examines the effect of this policy change on solar photovoltaic market. According to the study, solar PV market grew fast under FIT as well as under RPS. However, under RPS the size of subsidy for solar PV suppliers was shrunk substantially. In addition, market risk increased severly under RPS due to the volatility of price of renewable energy certificate (REC) as well as of the electricity market price. The small and medium suppliers of solar PV were suffered the most severly from these policy effects. Therefore, the policy reform of RPS is needed to alleviate the market risk of small and medium suppliers of solar PV.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.3
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• pp.515-522
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• 1994

The radiation characteristics of the conical corrugated feed horn are analyzed by the Gaussian beam mode theory. the electric field over the aperture can be expanded in terms of a set of Gaussian-Laguerre modes. It is proved that these modes are the solutions of the wave epuations for the paraxial approximation. A method, using the sum of the mode expansion coefficients instead of calculation only the fundamental mode, is presented in order to reduce the radiation pattern error. For illustrative examples, the radiation patterns of the corrugated horn antenna operting over C, Ku, and mm-wave band are calculated. Our results agree well with the results obtained by the vector potential method over each band, and also agree well with the measured value at 6.175GHz.