• 한국응용과학기술학회지
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• 제28권1호
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• pp.6-9
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• 2011

Step feed process was analyzed stoichiometrically for the optimal operation conditions in this study. In case of optimal operation conditions, minimum R (sludge recycling) value, r (internal recycling ratio) value, and n (influent allocation ratio) value for the step feed process to acquire the maximum TN removal efficiency were identified by theoretical analysis. Maximum TN removal efficiency, based on stoichiometric reaction, can be obtained by controlling n value for the step feed process.

• Journal of Biosystems Engineering
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• 제15권2호
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• pp.110-122
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• 1990

This study was undertaken to develop the feed rate control system for the head feed thresher by making use of the microprocessor and to evaluate the response of the system to a various threshing conditions. The control unit was composed of one-board microcomputer. The speed of the wet-paddy feeding chain was controlled by dc moter with PI controller. It was used the adaptive control method to maintain the constant feed rate regardless of the fed rice varieties. The sliding type potentiometer was used as the feed rate sensor, which was attached on the sheaf-holding apparatus. The mathematical models of the system components were derived and computer simulation was developed for investigating the parameters affecting on control performance and for estimating the response of the system. A one-board microcomputer-based feed rate control system developed in this study was properly functioned and assessed as adequate for the feed rate control system of the head feed thresher. Based on the simulation for the bundle feed, it was anticipated that the lower setting value of the cylinder speed(RL) is to be set higher than the limiting operational speed. In addition, the higher setting value of the cylinder speed(RH) is to be set lower than the limiting cylinder speed for threshing. The computer simulation for the continuous spread feed showed that the lower the setting value of straw layer thickness(LL) was set, the shorter the correction time. However, if too low LL may be established, the feed rate could not reach to its desired rate.

• Journal of Food and Nutrition Research
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• 제9권7호
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• pp.350-356
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• 2021

This study was conducted in Cheonan of central region in South Korea to identify alfalfa cultivars with superior adaptability to the local environment. To evaluate the growth characteristics, productivity, and feed value of 26 alfalfa cultivars, field experiments were conducted with a randomized block design (three replicates) for three years. Among the 26 alfalfa cultivars, "Natsuwakaba" showed the highest dry matter yield (DMY, 37,083 kg/ha), with a significantly higher three-year average than that of other cultivars. Furthermore, the three-year-average DMYs of "Alfalfa short" (31,044 kg/ha) and "Radar II Brand" (31,163 kg/ha) were significantly higher than those of other cultivars. In addition, differences among the feed values of the alfalfa cultivars were relatively less significant than the differences among their productivity, as the feed value was less influenced by the cultivation conditions and cultivars. Although "Jin Huang Hou" and "Certified organic" exhibited the highest feed values when cultivated in central region in South Korea, "Natsuwakaba" outperformed all cultivars in both productivity and feed value. The acid and neutral detergent fiber (ADF and NDF, respectively) contents of "Jin Huang Hou" (38.9% and 47.26%, respectively) were significantly lower than those of other cultivars. In contrast, the ADF and NDF contents of "Burgaltai" (46.52% and 55.56%, respectively) implied poor feed value upon cultivation in South Korea. The crude protein (CP) content in the alfalfa cultivars ranged from 14.95% to 19.44% during early flowering, and the highest CP content was observed for "Certified organic." The in-vitro digestibility of alfalfa was approximately 70% for all cultivars during early flowering, indicating good digestibility of most of the cultivars.

• 한국초지조사료학회지
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• 제40권3호
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• pp.138-148
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• 2020

This study was carried out to find out the changes in the growth characteristics and feed value of the three different whole-crop silage rice cultivars of whole-crop silage rice such as Jonong, Yeongwoo and Mogwoo to develop an efficient double cropping system. This study showed that there were significant differences biomass and feed values among cultivars but no clear difference among transplanting dates. Dry weight and height were in order of Mogwoo, Yeongwoo, Jonong (p<0.05). Dry weight and feed value of Jonong showed no significant difference after 21 days after heading (DAH), it was expected to be harvested before DAH 30 days. Yeongwoo showed a lower dry weight than Mogwoo, but heading date was earlier than Mogwoo, so one can expect a higher feed value than Mogwoo. Mogwoo had lower crude protein and total digestible nutrient than the other two cultivars but relative feed value in stem was higher than that of the other cultivars, but had higher dry weight than other cultivars so it was considered to take an advantage as a silage rice. Therefore, the results of this study suggest that the selection of whole-crop silage rice on the cropping system be made comprehensively by considering the heading characteristics of the cultivars and the feed value.

• 한국초지조사료학회지
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• 제37권2호
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• pp.116-124
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• 2017

This experiment was conducted to evaluate feed value and usability of soybean varieties as livestock forage. In this study, three soybean cultivars, OT93-26, Geomjeongsaeol, and Pungwon, were harvested at R5 (beginning seed development)- and R6 (full seed)-reproductive stages for analyzing feed value of soybean. Days to R5 stage harvest of OT93-26 among the three soybean cultivars was 55 days and the shortest while Pungwon took 103 days to reach at R6 stage. The R6-harvested soybeans had higher dry matter (DM) yields and crude protein (CP) content than the R5-harvested. However, both DM and CP were the highest in the R6-harvested Geomjeongsaeol. Contents of neutral detergent fiber (NDF) and acid detergent fiber (ADF) of Pungwon harvested at R5 were the highest whereas the R6-harvested Geomjeongsaeol had the lowest. Digestible dry matter (DDM), dry matter intake (DMI), and relative feed value (RFV) of the R6-harvested Geomjeongsaeol and Pungwon were higher than those of the R5-harvested, but in case of OT93-26, those at R6 stage were low rather than those at R5 stage. However, soybean could be used as alternative forage with high feed value for livestock. Taken together, Geomjeongsaeol could be used for developing new forage soybean varieties with high feed value, and R6 would be the optimum harvesting stage for yield and quality of forage soybean.

• 한국초지조사료학회지
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• 제41권4호
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• pp.280-286
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• 2021

The objective of this study was to prove the effect of pig slurry application with charcoal on nitrogen use efficiency (NUE), feed value and ammonia (NH₃) emission from maize forage. The four treatments were applied: 1) non-pig slurry (only water as a control), 2) only pig slurry application (PS), 3) pig slurry application with large particle charcoal (LC), 4) pig slurry application with small particle charcoal (SC). The pig slurry was applied at a rate of 150 kg N ha^-1, and the charcoal was applied at a rate of 300 kg ha-1 regardless of the size. To determine the feed value of maize, crude protein, dry matter intake, digestible dry matter, total digestible nutrient, and relative feed value were investigated. All feed value was increased by charcoal treatment compared to water and PS treatment. Also, the NUE for plant N was significantly higher in charcoal treatments (LC and SC) compared to PS treatment. On the other hand, there is no significant difference for feed value and NUE between LC and SC. The NH₃ emission was significantly reduced 15.2% and 27.9% by LC and SC, respectively, compared to PS. Especially, SC significantly decreased NH₃ emission by 15% compared to LC. The present study clearly showed that charcoal application exhibited positive potential in nitrogen use efficiency, feed value and reducing N losses through NH₃ emission.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.179-184
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• 2008

This paper presents the design of the feed forward controller to improve on the non-interference control performance of a single PWM converter in parallel for high-speed trains. The feed forward controller is designed to minimize the interference generated by converter switching in parallel operation of PWM converters. The gain value of the feed forward controller is calculated by inductance values of the input transformer. However, it is difficult to decide this gain value exactly because inductance values are changed by the operation condition of an input transformer. In this paper, the proposed design of feed forward controller can exactly decide the gain value using the leakage inductances estimated by detecting the variation of input current. the validity of the proposed feed forward controller is proved through the simulation results.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.322-322
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• 2022

Hay and haylage as forage are increasing in preference for cattle feed. Triticale (X Triticosecale Wittmack) is growing up as a forage crop due to its high production and feed value in South Korea. It is difficult to determine the harvesting stage of triticale for producing hay or haylage with the highest forage value and quality because feed and nutritional value by growth stages of triticale were not known in South Korea yet. In this study, we analyzed forage values, pH, and contents of organic acid, to confirm feed value and quality by growth stages of triticale. The triticale 'Joseong' was sown in the spring of 2022. The sample was prepared in 5 stages: seedling stage, booting stage, heading stage, 10 days after heading, and 20 days after heading. The triticale was dried under 10% and to about 50% moisture for hay and haylage respectively, and then both triticales were fermented anaerobically at room temperature for 40 days. The pH value in all hay and haylage became lower as the triticale was grown up, although the pH value of all triticale hays and haylages ranged between 7.05-5.68. The content of lactic acid in all triticale hays was almost meaningless. The contents in the haylage of the seedling stage were the highest (2.39%) among the haylages, even though those of 20 days after the heading stage (1.67%) were the lowest, which showed a similar tendency with pH value. Conclusionally, the results implied that the feed value and quality of triticale haylage were affected by harvesting time but not hay.

• Fisheries and Aquatic Sciences
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• 제18권2호
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• pp.203-209
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• 2015

Low-value fish is the most commonly used feed in Asian fish farms despite the fact that its application is controversial in regard to the sustainability and biosecurity of aquaculture. In this study, the causal agent of a disease outbreak at a Korean rockfish Sebastes schlegeli farm was investigated to determine whether the low-value fish used at the farm was the source. Infected Korean rockfish and Pacific sand eel used as feed were sampled from the farm, and bacterial cultures recovered from the internal organs of all sampled rockfish were isolated as pure cultures and later identified as Vibrio harveyi. The causal agent of the disease was also isolated from the kidneys of some of the sampled Pacific sand eels. This study provides additional evidence that the low-value fish used as feed at fish farms can be a key source of infectious diseases.

• 한국토양비료학회지
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• 제50권5호
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• pp.391-400
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• 2017

Italian ryegrass (IRG) is one of the fastest growing grasses available to farmers. It offers rapid establishment and starts growing early in the following spring and has fast regrowth after defoliation. So, IRG can be utilized as the dominant/single species of grass used in a farming system, or to play a role as a large producing pasture and sacrificial paddock. The objective of this study was to develop the use of unmanned aerial vehicle (UAV) for the evaluation of feed value of IRG. For this study, UAV imagery was taken on the Nonsan regions two times during the IRG growing season. We analyzed the relationships between $NDVI_{UAV}$ and feed value parameters such as fresh matter yield, dry matter yield, acid detergent fiber (ADF), neutral detergent fiber (NDF), total digestible nutrient (TDN) and crude protein at the season of harvest. Correlation analysis between $NDVI_{UAV}$ and feed value parameters of IRG revealed that $NDVI_{UAV}$ correlated well with crude protein (r = 0.745), and fresh matter yield (r = 0.655). According to the relationship, the variation of $NDVI_{UAV}$ was significant to interpret feed value parameters of IRG. Eight different regression models such as Linear, Logarithmic, Inverse, Quadratic, Cubic, Power, S, and Exponential model were used to estimate IRG feed value parameters. The S and exponential model provided more accurate results to predict fresh matter yield and crude protein than other models based on coefficient of determination, p- and F-value. The spatial distribution map of feed values in IRG plot was in strong agreement with the field measurements in terms of geographical variation and relative numerical values when $NDVI_{UAV}$ was applied to regression equation. These lead to the result that the characteristics of variations in feed value of IRG according to $NDVI_{UAV}$ were well reflected in the model.