• Journal of the Korean Society for Precision Engineering
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• v.26 no.3
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• pp.25-31
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• 2009

Femto-second laser ablation with the various feed velocities of the Invar alloy and the micro surface milling for the processing condition were studied. We used a regenerative amplified Ti:sapphire laser with a 1kHz repetition rate, 184fs pulse duration time and 785nm wavelength. Femto-second laser pulse was irradiated on the Invar alloy with the air blowing at the condition of various laser peak powers and feed velocities. An ablation characteristic according to feed velocity of the Invar alloy was appeared as the non-linear type at different zone of energy fluence. The micro surface milling of the Invar alloy using a mapping method was investigated. The optimal condition of micro surface milling was laser peak power of 22.8mW, feed velocity of 1 mm/s, beam gap of $1{\mu}m$. With the optimal processing condition, the fine rectangular shape without burr and thermal damage was achieved. Using the femto-second laser system, it demonstrates excellent tool for micro surface milling of the Invar alloy without heat effects and poor edge.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.10
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• pp.1475-1481
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• 2002

The study was conducted to evaluate the effect of early feed restriction on growth, fat accumulation and meat composition in unsexed broiler chickens. In experiment 1, three hundred and fifty one-day-old broiler chicks were divided into 7 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group and the other six groups were fed 25% ad libitum (25% multiplied by amount of feed intake of ad libitum chicks at the previous day) for 4 or 6 days, 50% ad libitum for 4 or 6 days, and 75% ad libitum for 4 or 6 days. In experiment 2, five hundred broiler chicks were divided into 10 groups. Each treatment group was represented by five replicates of ten broilers each. One group was fed ad libitum as the control group. Three initial age at which broilers were restricted (2, 4 or 6 days of age) and three type of feed restriction (physical restriction, meal feeding and diet dilution) ($3{\times}3$) were examined. They were restricted feeding for 6 days. Experimental results showed that broilers fed 25% ad libitum for 4-6 days tended to reduce leg meat fat with lower abdominal fat (p<0.05) (experiment 1). Breast meat fat was significantly higher in restricted broilers (p<0.01). Plasma triglyceride was higher in broilers fed 75% ad libitum for 4-6 days. In experiment 2, abdominal fat was lower in restricted broilers (p<0.05). Breast meat fat was significantly higher (p<0.01), whereas leg meat fat was significantly lower (p<0.05) in restricted broilers. Plasma triglyceride was significantly higher in physical feed restriction for 4 days, meal feeding for 4 days and diet dilution for 6 days (p<0.05). In conclusion, to reduce fat accumulation in abdomen and leg meat, broilers should be fed 25% ad libitum for 6 days started at 4 days, or subjected to meal feeding (6 hours per day for 6 days) started at 6 days.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.3
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• pp.378-385
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• 2013

The aim of this study was to examine the effect of variety and growing conditions of wheat on broiler performance and nutrient digestibility. One hundred and sixty-four wheat samples, collected from a wide range of different sources, locations, varieties and years, were analyzed for a range of chemical and physical parameters. Chemical and physical parameters measured included specific weight, thousand grain weight (TG), in vitro viscosity, gross energy, N, NDF, starch, total and soluble non-starch polysaccharides (NSP), lysine, threonine, amylose, hardness, rate of starch digestion and protein profiles. Ninety-four of the wheat samples were selected for inclusion in four bird trials. Birds were housed in individual wire metabolizm cages from 7 to 28 d and offered water and feed ad libitum. Dry matter intake (DMI), live weight gain (LWG) and gain:feed were determined weekly. A balance collection was carried out from 14 to 21 d for determination of apparent metabolizable energy (AME), ME:gain, DM retention, oil and NDF digestibility. At 28 d the birds were sacrificed, the contents of the jejunum removed for determination of in vivo viscosity and the contents of the ileum removed for determination of ileal DM, starch and protein digestibility. The wheat samples used in the study had wide-ranging chemical and physical parameters, leading to bird DMI, LWG, gain:feed, ME:GE, AME content and ileal starch and protein digestibility being significantly (p<0.05) affected by wheat sample. A high level of N fertilizer application to the English and NI wheat samples tended to benefit bird performance, with increases of up to 3.4, 7.2 and 3.8% in DMI, LWG and gain:feed, respectively. Fungicide application also appeared to have a positive effect on bird performance, with fungicide treated (+F) wheat increasing bird DMI, LWG and gain:feed by 6.6, 9.3 and 2.7%, over the non-fungicide treated (-F) wheats. An increase (p<0.1) of 9.3% in gain:feed was also observed at the low seed rate of 40 compared to 640 seeds/$m^2$. It was concluded that the type of wheat sample and environmental growing conditions significantly affects bird performance when fed wheat-based diets.

• 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 the Institute of Electronics Engineers of Korea TC
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• v.47 no.11
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• pp.77-83
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• 2010

This paper presents the dual resonance PIFA(Planar Inverted F-Antenna) which satisfies the requirements of the 802.11n standard at both 2.4 GHz and 5 GHz frequency bands. Patch for 2.4 GHz and U-Type slot for 5 GHz were used for dual resonance, respectively. In this paper, the characteristics of an antenna were investigated by varying locations of short plate and feed point, the width of the short plate, the thickness and the location of U-Type slot. To investigate the characteristics of the PIFA, HFSS(High Frequency Structure Simulation) for the simulation was used. And the measurement results of a fabricated PIFA were compared with the simulated ones. The measurement and simulation results show that good dual resonance characteristics as the thickness of U-type slot decreases and when the location of U-type slot is far from the feed point.

• Journal of Biosystems Engineering
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• v.8 no.2
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• pp.39-48
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• 1983

This study was performed to obtain the basic data which could be used for the modification of the manual center-burner-type rice-husk furnace into a small scale automatic type for the multi-purpose use in the farm. For this purpose, first, the utilization feasibility of the rice-husk furnace in the farm was analyzed briefly in aspects of available amount of rice-husk for the fuel, annual operation time and replaceble amount of residential heating energy with rice-husk in the farm. For the experiment a prototype furnace geared with an automatic feeding device was fabricated, and feed rate, mold size and chimney height were changed to investigate the combustion efficiency of rice-husk and thermal efficiency of the furnace. Also, optimum and limiting operational factors were observed in each treatments. The results obtained are summarized as follows. 1. If the rice-husk is intensively used for residential heating in the farm for winter season, on an average 51 percent of the total heating energy can be replaced with the rice-husk. Therefore, development of a small scale automatic rice-husk furnace was recognized to be feasible. 2. The operational condition depending on husk-feed rates was very important factor for successive steady burning operation of the given furnace. When the feed-rate was 1.5 kg/hr, the top of the burning zone should be kept at the position about 55 cm from the bottom of the combustion chamber with the periodic removal of ash (termed as steady state position), which was 18 cm above the mold waist. When the feed rates were 2.4 kg/hr and 3.0 kg/hr, the steady state position was at about 4 cm above the mold waist. 3. The mold size affected inflow rate of air into the furnace and consequently CO content in the exhaust gas. The relatively bigger mold gave positive effect on the air-inflow rate. 4. When the husk-feed rates were 1.5 kg/hr, 2.4 kg/hr, 3.0 kg/hr, the combustion efficiencies of the rice-husk were 98.5%, 97.4% and 95.0%, the thermal efficiencies of the furnace were 93.4%, 93.2% and 87.6%, and CO content in the exhaust gas were 1.21%, 1.03%, and 2.43%, respectively. The air-inflow rates were decreased with the increase of feed rates. When the amount of excess air was 30-40%, the CO content in the exhaust gas was at the minimum level. 5. When the chimney height was lowered from 260 cm to 96 cm, the air-inflow rate was slightly decreased, but the average temperature in the combustion chamber, CO content in the exhaust gas and combustion and thermal efficiencies were not changed significantly. 6. The incidental problems associated with the protytype furnace were accumulation of the ash inside the mold, accumulation of the cinder between the outer-drum of the furnace and the combustion chamber wall, and accumulation of the cinder in the chimney.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.2
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• pp.159-169
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• 2016

The goats raised in the barn are usually fed on fresh grass. As dry forage can be stored for long periods in large amounts, dry forage feeding makes it possible to feed large numbers of goats in barns. This review explains the physiological factors involved in suppressing dry forage intake and the cause of drinking following dry forage feeding. Ruminants consume an enormous amount of dry forage in a short time. Eating rates of dry forage rapidly decreased in the first 40 min of feeding and subsequently declined gradually to low states in the remaining time of the feeding period. Saliva in large-type goats is secreted in large volume during the first hour after the commencement of dry forage feeding. It was elucidated that the marked suppression of dry forage intake during the first hour was caused by a feeding-induced hypovolemia and the loss of $NaHCO_3$ due to excessive salivation during the initial stages of dry forage feeding. On the other hand, it was indicated that the marked decrease in feed intake observed in the second hour of the 2 h feeding period was related to ruminal distension caused by the feed consumed and the copious amount of saliva secreted during dry forage feeding. In addition, results indicate that the marked decreases in dry forage intake after 40 min of feeding are caused by increases in plasma osmolality and subsequent thirst sensations produced by dry forage feeding. After 40 min of the 2 h dry forage feeding period, the feed salt content is absorbed into the rumen and plasma osmolality increases. The combined effects of ruminal distension and increased plasma osmolality accounted for 77.6% of the suppression of dry forage intake 40 min after the start of dry forage feeding. The results indicate that ruminal distension and increased plasma osmolality are the main physiological factors in suppression of dry forage intake in large-type goats. There was very little drinking behavior observed during the first hour of the 2 h feeding period most water consumption occurring in the second hour. The cause of this thirst sensation during the second hour of dry forage feeding period was not hypovolemia brought about by excessive salivation, but rather increases in plasma osmolality due to the ruminal absorption of salt from the consumed feed. This suggests the water intake following dry forage feeding is determined by the level of salt content in the feed.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.12
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• pp.2187-2195
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• 2000

A water treatment system using membrane separation technology can provide stable effluent quality and its maintenance is relatively easy comparing to the conventional water treatment system. In addition, the membrane filtration system is very compact such that it can replace existing water treatment processes of coagulation/sedimentation/filtration by only one process. However, a major problem associated with membrane filtration is flux decline with operating time due to concentration polarization and fouling, so a systematic study on evaluation of long-term filtration performance is necessary. A membrane filtration system using tubular type ultrafiltration membranes with MWCO of 30.000 Da was constructed for this study and it had been operated in a feed-and-discontinuous bleed mode. Flux was stabilized after operation of 1.500 hours and maintaining above 25 LMH until 4.000 hours. Contaminants causing SS and turbidity were almost completely removed while the $UV_{260}$ and DOC removals were 55% and 49%, respectively. A simple mass balance equation was developed to predict maximum concentrations of SS, turbidity, $UV_{260}$ and DOC in a operation cycle. For SS and turbidity the measured max, concentrations in each cycle agree well with the predicted values while the measured max, concentrations of $UV_{260}$ and DOC were 59% and 37% of the predicted values, respectively.

• Korean Journal of Poultry Science
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• v.10 no.1
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• pp.53-59
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• 1983

The stuff was carried out in order to investigate the effect of level of feed input on AME (AME$\_$F/) and TME (AME$\_$FC/) values and of diet types of experiment on TME values of corn. yellow and soybean meal Experimental diet was fed as type of balanced diet instead of single ingredient at the level of 25. 50 and 75gm The results obtained were as follows : 1. The AME and AME$\_$F/ values of corn ana soybean meal were significantly different (P＜.05) at each level of feed input. especially at 50gm feed input. the AME and AME$\_$F/ values of corn and soybean meal were the highest of all treatments and the AME of corn between 50gm and 75gm of feed input was not found significant difference(P＞.05). 2. The TME and AME$\_$FC/ values of corn were not significantly different (P＞.05) at each feed input but those of soybean meal differed greatly (P＜.05) the fact that AME$\_$FC/ and TME values of soybean meal were the highest at 50gm of feed input was indicative that there were problems to measure AME$\_$FC/ and TME values of soybean meal. 3. There was not found significant difference (P＞.05) according to the type of diet when fed single and balanced diet.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.7
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• pp.282-287
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• 2003

″H″ type resonator has the advantage for the miniaturization of high-T7 superconducting (HTS) microstrip antenna in comparison with the conventional microstrip antenna such as rectangular type or circular type. In this paper we designed miniaturized HTS antennas using this "H"-type resonator and reported the characteristics of our antennas including return loss, bandwidth, radiation patterns, efficiency and so on. To fabricate the "H" type antenna, HTS YBa$_2$Cu$_3$$O_{7-x}$ (YBCO) thin films were deposited on MgO substrates using rf-magnetron sputtering. For comparison between normal conducting antennas and superconducting antennas, the gold antennas with the same dimension were also fabricated. An aperture coupling was used for impedance matching between 50 $\Omega$ feed line and HTS radiating patch. The ″H" type superconducting antenna showed the performance of 1.38 in SWR, 26 % in efficiency, and 13.8 dB in the return loss superior to the normal conducting counterpart.