• Journal of Biosystems Engineering
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• v.5 no.1
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• pp.1-14
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• 1980

Threshing operation may be one of the most important processes in the paddy post-production system as far as the grain loss and labor requirement are concerned . head-feeding type threshers commercially available now in Korea originally were developed for threshing dry paddy in the range of 15 to 17 % in wet basis. However, threshing wet-paddy with the grain moisture content above 20 % has been strongly recommended, especially for new high-yielding Indica -type varieties ; (1) to reduce high grain loss incurred due to the handling operations, and (2) to prevent the quantitative and qualitative loss of milled -rice when unthreshed grains are rewetted due to the rainfall. The objective of this study were to investigate the adaptability of both a head-feeding type thresher and a throw-in type thresher to wet-paddy , and to find out the possiblilities of improving the components of these threshers threshing. Four varieties, Suweon 264 and Milyang 24 as Tongil sister line varieties, minehikari and Jinhueng as Japonica-type varieties, were used at the different levels of the moisture content of grains. Both the feed rate and the cylinder speed were varied for each material and each machine. The thresher output quality , composition of tailing return, and separating loss were analyzed from the sampels taken at each treatment. A separate experiment for measurement opf the power requirement of the head-feeding type thresher was also performed. The results are summarized as follows : 1. There was a difference in the thresher output quality between rice varieties. In case of wet-paddy threshing at 550 rpm , grains with branchlet and torn heads for the Suweon 264 were 12 % and 7 % of the total output in weight, respectively, and for the Minehikari 4.5 % and 2 % respectively. In case of dry paddy threshing , those for the Suweon 264 were 8 % and 5% , and for the Minehikari 4% and 1% respectively. However, those for the Milyang 23 , which is highly susceptable to shattering, were much lower with 1 % and 0.5% respectively, regardless of the moisture content of the paddy. Therefore, it is desirable to breed rice varieties of the same physical properties as well as to improve a thresher adaptable to all the varieties. Torn heads, which increased with the moisture content of rall the varieties except the Milyang 23 , decreased as the cylinder speed increased, but grains with branchlet didnt decrease. The damaged kernels increased with the cylinder speed. 3. The thresher output quality was not affected much by the feed rate. But grains with branchlet and torn heads increased slightly with the feed rate for the head-feeding type thresher since higher resistance lowered at the cylinder speed. 4. In order to reduce grains with branchlet and torn heads in wet-paddy threshing , it is desirable to improve the head-feeding type thresher by developing a new type of cylinder which to not give excess impact on kernels or a concave which has differenct sizes of holes at different locations along the cylinder. 5. For the head-feeding type thresher, there was a difference in separating loss between the varieties. At the cylinder speed of 600 rpm the separating losses for the Minehikari and the Suweon 264 were 1.2% and 0.6% respectively. The separating loss of the head-feeding type thresher was not affected by the moisture content of paddy while that of the Mini-aged thresher increased with the moisture content. 6. From the analysis of the tailings return , to appeared that the tailings return mechanism didn't function properly because lots of single grains and rubbishes were unnecessarily returned. 7. Adding a vibrating sieve to the head-feeding type thresher could increase the efficiency of separation. Consequently , the tailing return mechanism would function properly since unnecessary return could be educed greatly. 8. The power required for the head-feeding type thresher was not affected by the moisture content of paddy, but the average power increased linearly with the feed rate. The power also increased with the cylinder speed.

• Journal of Embryo Transfer
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• v.21 no.3
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• pp.177-182
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• 2006

This study was conducted to investigate the effects of melengesterol acetate (MGA) and $PGF_{2{\alpha}}$ administrations on serum progesterone level, synchrony of estrus and conception rates in Han-woo. Firstly, ten heifers and one freematin were fed 0.5 mg MGA/day for 14 days in a grain carrier, and after 19 days of MGA feeding, a single injection of 25 mg $PGF_{2{\alpha}}$ were treated. Blood samples were collected to evaluate serum progesterone concentrations from the start of feeding of MGA until the end of feeding and subsequent estrous detection and artificial insemination (AI) at 3 days intervals, and on days of $PGF_{2{\alpha}}$ injection, estrous detection, AI, and 15th and 60th days after AI. The level of progesterone in the blood began to increase from 7 days after MGA feeding, and 9 days after feeding it became 5.4 ng/ml and maintained that level thereafter. On the 33th day when the $PGF_{2{\alpha}}$ was injected, it reached the peak level of 7.6 ng/ml. However, 2-3 days after $PGF_{2{\alpha}}$ injection, it dropped to 1.4 ng/ml drastically (p<0.05). Secondly, one hundred and ninety four Hanwoo heifers or cows were divided into two groups to compare estrous induction and conception rates: the one treated with MGA and $PGF_{2{\alpha}}$, (n=104) and the other with $PGF_{2{\alpha}}$ treatment (two injections at 11 days interval, n=90). The heifers or cows treated with MGA and $PGF_{2{\alpha}}$ were identical to those used as above. The percentages of heifers or cows showed estrus were higher in the $MGA+PGF_{2{\alpha}}$ treatment (91.3%) than in the $PGF_{2{\alpha}}$ treatment (72.2%, p<0.05). Conception rates were also higher in the $MGA+PGF_{2{\alpha}}$ treatment (94.2%) than in the $PGF_{2{\alpha}}$ treatment (88.9%, p<0.05). The results of this experiment indicate that estrus synchronization using $MGA+PGF_{2{\alpha}}$ is more effective than that using $PGF_{2{\alpha}}$ (two injections) in Hanwoo.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3137-3143
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• 2009

In this paper, a single arm spiral antenna has been investigated about the characteristics of polarization and tilt beam. If a circumference length of spiral is bigger than a wavelength, it have a characteristic of varying maximum radiation beam direction. In addition, circular polarizations (RHCP, LHCP) can be variable by the feeding points (inner, outer). Also maximum beam directions tilt in different direction according to the circular polarizations, LHCP and RHCP. These characteristics of single arm spiral antenna are able to apply in the beam forming, diversity, MIMO application which has dual polarization using an antenna element.

• Korean Journal of Agricultural Science
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• v.37 no.1
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• pp.53-60
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• 2010

Two experiments were conducted to investigate the effect of probiotics on the malodor removal. In experiment 1, dietary effects (several malodorous gas concentration of excreta, dry matter metabolizability, and blood profiles) were determined using laying hens. A total of 30 Hy-line brown layers, 68-wk of age, were randomly allocated into 5 groups with 3 replicates of 2 birds each. The treatments were probiotics free, 0.2% and 0.4 % addition of mixed probiotics (Bacillus subtilis PNG-4 +Lactobacillus acidophilus LAS), and 0.2 and 0.4 % addition of single probiotics (Bacillus subtilis PNG-4). In experiment 2, the effects of mixing of probiotics into the excreta on the malodorous gas removal was investigated. There were three treatments (probiotics free, Bacillus subtilis PNG-4 +Lactobacillus acidophilus LAS, and Bacillus subtilis PNG-4) with three replicates. The malodorous gas concentrations were detected at 0, 3, 7 and 14 day of incubation. In experiment 1, ammonia concentration was significantly decreased by feeding mixed probiotics at 14th day of incubation. However, amines, hydrogen sulfide, ethylmercapthan, and methylmercapthan were not significantly affected by mixed probiotics. Dry matter metabolizability was significantly increased by feeding probiotics, but no significant differences between single and mixed probiotics. There was no significant differences in blood profiles. In experiment 2, mixing of probiotics into the excreta did not affect the concentration of ammonia, amines, hydrogen sulfide, ethylmercapthan, and methylmercapthan. Therefore, these experiments suggested that Bacillus subtilis PNG-4 + Lactobacillus acidophilus LAS supplementations could improve ammonia gas removal, and dry matter metabolizability in layers. Also, decrease of ammonia concentration was higher in mixed probiotics group compare to the single probiotics group. On the other hand, mixing of probiotics into the excreta appeared not to be a useful method.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.13-22
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• 2022

In this paper, we propose single and array antenna with dual linear polarization characteristics for 28 GHz band. The proposed antenna is designed two microstirp feeding structure and Taconic TLY-5 substrate, which is thickness 0.5 mm, and the dielectric constant is 2.2. The size of single patch antenna is 3.4 mm×3.4 mm, and total size of single antenna is 15.11 mm×15.11 mm. Also, the size of array antenna is 3.15 mm×3.15 mm, and total size of array antenna is 21.5 mm×13.97 mm. From the fabrication and measurement results, for 1×2 array antenna, in case of vertical polarization, cross polarization ratios are obtained from 14.23 dB to 20.79 dB and in case of horizontal polarization, cross polarization ratios are obtained from 14.31 dB to 22.74 dB for input port 1. in case of vertical polarization, cross polarization ratios are obtained from 15.75 dB to 25.88 dB and in case of horizontal polarization, cross polarization ratios are obtained from 14.70 dB to 22.82 dB for input port 2.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.3
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• pp.420-425
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• 2008

The storage of rice polishing (RP) with and without addition of antioxidant for sixteen weeks and its effect on rancidity and metabolizable energy values during the summer season was determined. Fifteen Single Comb White Leghorn cockerels of approximately uniform age and weight were procured and kept in metabolic cages under standard feeding and management practices. Five force feeding trials were conducted. In the first trial, fresh RP with 0 weeks of storage (diet 1 and 2) was used followed by four feeding trials with 4 (diet 3, 4), 8 (diet 5, 6), 12 (diet 7, 8), and 16 (diet 9, 10) weeks of storage of RP. The same birds were used in all trails. The birds were fasted for a period of 21 h, followed by force feeding of 20 g of RP with and without antioxidant for all storage periods. The control/fasting group was also maintained to measure endogenous fecal losses. Excreta were collected after 48 h for the determination of AME and TME values of RP. Along with the biological trials, laboratory assay of the RP stored with and without antioxidant was conducted to measure the extent of rancidity in terms of Thiobarbituric acid value (TBA). The TBA values were affected (p<0.05) by storage period and the values increased when the storage period increased from 4 to 16 weeks. However, the TBA values were significantly reduced (p<0.05) when RP was stored after addition of antioxidant when compared with the values obtained from RP stored without antioxidant (diet 3 vs. 4, 5 vs. 6, 7 vs. 8, and 9 vs. 10). The AME MJ/kg and TME MJ/kg values of RP were neither affected by increase in storage period nor addition of antioxidant. The findings of this study revealed that there was no effect of rancidity and storage time on the nutritive value, AME or TME of RP in poultry. However, TBA values were increased with the increase in storage period.

• Journal of Nutrition and Health
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• v.25 no.7
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• pp.543-554
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• 1992

True metabolizable energy(TME) is believed a better indicator for animal performance than apparent metabolizable energy (AME) for excluding the endogenous energy losses from excreta, However few researches have been conducted to compare superiority of any energy systems through practical animal feeding tests. Present study was to compare the energy systems in young chicks in terms of predictability of energy intake for the birds performances including body energy retention and of methodological accuracy by evaluating reproducibility and additi-vity of energy values of feed ingredients and compound diets. Five ingredients such as yellow corn wheat soybean meal fish meal and wheat bran were measured for their various biological energy values. in the first feeding trial chicks were restric-ted-fed the basal diet at 80, 60 and 40% on weight basis of the amount of feed ingested by chicks fed ad libitum the same diet. chicks in the second trial were also restricted-fed diets at levels of 80, 70, 60 and 50% on energy basis of the amount consumed by the basak duet group fed ad libitum The diets in the latter trial were however composed of differeent formulations from the basal diet. One-week-old Single Comb White Leghorn male chicks were individually alloted in a cage on 10 cages/treatment basis and fed the diets for 14 days. Individual carcass energy was measured after the feeding trials. Coefficients of variation of energy measurements were lesser for nitrogen-corrected AME and TME(AMEn & TMEn respectively) than AME and TME values suggesting taht reprodu-cibility of energy determinations by former systems could be better than the latters. The coeffi-cients for AME and TME were almkost of the same values. Additivity obtained by the rations between the calculated values and catual measurements appeared quite satisfactory for all the energy systems. Those of AME and TME however were relatively better than the other systems. Regression coefficient ${r}^2$ between energy intake by various systems and chick performances appeared higher for TME, AMEn and TMEn than AME implying that the former systems could provide better predictability for body weight gain and energy retention than the AME. The ${r}^2$ values for TME and AMEn particularly for body weight gain were on the average 0.967 and 0.960 respectively. In conclusion TME or AMEn can be recommended as choice for dietary energy system in terms of performance predictability of the birds and of procedural convenience for the measurements.

• ALGAE
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• v.38 no.1
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• pp.57-70
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• 2023

The mortality rate of red-tide dinoflagellates owing to predation is a major parameter that affects their population dynamics. The dinoflagellates Ansanella granifera and Ansanella sp. occasionally cause red tides. To understand the interactions between common heterotrophic protists and A. granifera, we explored the feeding occurrence of nine heterotrophic protists on A. granifera and the growth and ingestion rates of the heterotrophic dinoflagellate Gyrodinium dominans on A. granifera as a function of prey concentration and those of Oxyrrhis marina at a single high prey concentration. The heterotrophic dinoflagellates Aduncodinium glandula, G. dominans, Gyrodinium moestrupii, Luciella masanensis, Oblea rotunda, O. marina, Polykrikos kofoidii, and Pfiesteria piscicida and the naked ciliate Strombidium sp. were able to feed on A. granifera. With increasing mean prey concentrations, the growth and ingestion rates of G. dominans feeding on A. granifera rapidly increased and became saturated or slowly increased. The maximum growth and ingestion rates of G. dominans on A. granifera were 0.305 d^-1 and 0.42 ng C predator^-1 d^-1 (3.8 cells predator^-1 d^-1), respectively. Furthermore, the growth and ingestion rates of O. marina on A. granifera at 1,700 ng C mL^-1 (15,454 cells mL^-1) were 0.037 d^-1 and 0.19 ng C predator^-1 d^-1 (1.7 cells predator^-1 d^-1), respectively. The growth and ingestion rates of G. dominans and O. marina feeding on A. granifera were almost the lowest among those on the dinoflagellate prey species. Therefore, G. dominans and O. marina may prefer A. granifera less than other dinoflagellate prey species. The low mortality rate of A. granifera may positively affect its bloom formation.

• Animal cells and systems
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• v.7 no.4
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• pp.331-335
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• 2003

Vertebrates with different habitats have different proportions of visual cells, with the rod cells responding to scotopic vision and the cone cells responding to photopic and color vision in their retinas. The present work studied whether the kinds and arrangement patterns of the cone cells and interlocking morphology of the lens were related to the kind of preys and habitats in the genus Zacco. The retinas were observed by a light microscopy using H-E staining method and the interlocking formula of the lens fibers were investigated by a scanning electron microscopy. The interlocking formula of the lens fibers of Z. temmincki is an ' anchor and socket ' connection, and that of Z. platypus is a ' ball and socket ' connection. The cone cells of Z. platypus and Z. temmincki constituted compacted mosaic patterns of row type. Away from the center, the double and single cone cells gradually increased in diameter. Zacco temmincki had identical double cone cells and Z. platypus had non-identical double and single cone cells. The eyes of Z. temminckifeeding on a moving aquatic insects in relative limpid water and swift current of mid and upper stream have better resolution than that of Z. platypus feeding on mainly adhesive algae and some aquatic insects in slightly turbid water of mid stream.

• Journal of Power Electronics
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• v.15 no.3
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• pp.806-818
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• 2015

Based on the inherent relationship between dc-bus voltage and grid feeding active power, two dc-bus voltage regulators with different references are adopted for a grid-connected PV inverter operating in both normal grid voltage mode and low grid voltage mode. In the proposed scheme, an additional dc-bus voltage regulator paralleled with maximum power point tracking controller is used to guarantee the reliability of the low voltage ride-through (LVRT) of the inverter. Unlike conventional LVRT strategies, the proposed strategy does not require detecting grid voltage sag fault in terms of realizing LVRT. Moreover, the developed method does not have switching operations. The proposed technique can also enhance the stability of a power system in case of varying environmental conditions during a low grid voltage period. The operation principle of the presented LVRT control strategy is presented in detail, together with the design guidelines for the key parameters. Finally, a 3 kW prototype is built to validate the feasibility of the proposed LVRT strategy.