• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.66-69
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• 2008

In this paper, The author present a load current feed-forward compensator by method that improve voltage controller of Step-down Chopper to get stable output voltage to sudden change of load current. To confirm the characteristicsof a presented load current feed -forward compensator compared each transfer function of whole system that load current feed-forward compensator is added with transfer function of whole system that existent voltage controller is included using Mason gains formula in Root locus and Bode diagram. As a result the pole of system is improved, extreme point of the wave and system improves, and size of peak value and phase margin of break frequency in resonance frequency confirmed that is good. Therefore, presented control technique could confirm that reduce influence by perturbation and improves stationary state and dynamic characteristics in output of Step-down Chopper.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.99-102
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• 1999

In recent years, attempts have been made to greatly improve the display quality of active-matrix liquid crystal display devices, and many techniques have been proposed to solve such problems as gate signal delay, feed-through voltage and image sticking. To improve these problems which are caused by the fried-through voltage, we have evaluated new driving methods to reduce the fled-through voltage. Two level gate-pulse was used for the gate driving of the cst-on-common structure pixels. And two-gate line driving methods with the optimized gate signals were applied for the cst-on-gate structure pixels. These gate driving methods were better feed-through characteristics than conventional simple gate pulse. The evaluation of the suggested driving methods were performed by using a TFT-LCD array simulator PDAST which can simulate the gate, data and pixel voltages of a certain pixel at any time and at any location on a TFT array. The effect of the new driving method was effectively analyzed.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.5
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• pp.597-607
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• 1998

Processing is generally employed to alter the physical and chemical properties of feeds used in pig diets, using hammer/roller mills, pellet mills and extruders/expanders. The reported optimum particle sizes of corn are approximately $500{\mu}m$, $500-700{\mu}m$, $400-600{\mu}m$, for nursery, growing-finishing, and breeder pigs respectively. Optimum particle size of grains are affected by diet complexity. There was a trend towards reducing particle size in order to increase ADG in pigs fed a simple diet, though such was not the case for pigs fed a complex diet. Uniformity of particle size also affects the nutritional values of swine feeds. Uniform particle sizes would consistently give greater nutrient digestibilities. In terms of pellet quality, it is reported that a higher incidence of fmes in pelleted feeds has a direct correlation with poorer feed conversion ratio in pigs. Particle and pellet sizes are also very important for pelleting in terms of grinding, digestibility, stomach ulceration and pellet durability. A particle size of $600{\mu}m$, or slightly less, seemed optimal for com in fmishing pigs, and the 5/32 in. diameter pellets supported the best efficiencies of gain during nursery and finishing phases. Extruder and/or expander processes would allow the feed industry an increased flexibility to utilize a wider spectrum of feed ingredients, and improve pellet quality of finished feeds. It would appear that extruded or expanded diets containing highly digestible ingredients have little effect on the growth performance of pigs, and the feeding values of the feeds over pelleted diets were not improved as pigs grew. The extruder or expander is much more effective than a pelletizer in salmonella control. Gastric ulcerations and/or keratinizations were consistently reported in pigs fed mash and processed diets containing finely ground grains, whereas carcass quality was not affected by diet processing methods such as pelleting, extruding or expanding. In corn- or sorghum-based diets, the electrical energy consumption is 4-5 times higher in the expanding than in the pelleting process. But the expander's processing cost was half of that shown by an extruder. Finally, the decision of which feed processing technology to adopt would depend on the processing cost, and any potential improvement in growth performance and digestibilities of nutrients should offset the increased operating and capital costs related to the extruder/expander technology over mash or pelleting processes in pigs.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.12
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• pp.46-53
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• 1996

Micro drilling is one of the most important machining types and its necessity becomes more and more increasing in the whole field of industry. Micro drilling, however, has few the case of practical application, because it requests high techniques : manufacturing micro drill, treating chip, producting precise hole shape and progressing machining effeciency. Micro drilling has a technical problem: drill breakage from the lack of drill rigdity and the interuption of chip. It is, therefore, essential to select the proper cutting conditions and the step fed for the method solving the lack of rigidity and the interruption of chip. Especially, step feed is very efficient to avoid the breakage of drill, but bring about reducing of cutting efficiency. The study on step feed must be requested more than the present in the near future. The purpose of this paper is to investigate experimentally about cutting conditions which affect on tools and round errors and to estimate about the effect of step feed as well as optimal step feed size to solve the breakage of drill.

• Membrane and Water Treatment
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• v.4 no.1
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• pp.11-25
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• 2013

Emulsion liquid membrane (ELM) process suffers from emulsion instability problem. So far, emulsion produced by mechanical methods such as stirrer and homogenizer has big size and high emulsion breakage. This paper discussed the application of emulsion produced by sonicator to extract cadmium in a batch ELM system. The emulsions consist of N,N-Dioctyl-1-octanamine (trioctylamine/TOA), nitrogen trihydride (ammonia/NH4OH), sorbitan monooleate (Span 80), and kerosene as carrier, stripping solution, emulsifying agent, and organic diluent, respectively. Effects of comprehensive parameters on extraction efficiency of Cd(II) such as emulsification time, extraction time, stirring speed, surfactant concentration, initial feed phase concentration, carrier concentration, volume ratio of the emulsion to feed phase, and pH of initial feed phase were evaluated. The results showed that extraction efficiencies of Cd(II) greater than 98% could be obtained under the following conditions: 15 minutes of emulsification time, 4 wt.% of Span 80 concentration, 4 wt.% of TOA concentration, 15 minutes of extraction time, 250 rpm of stirring speed, 100 ppm of initial feed concentration, volume ratio of emulsion to feed phase of 1:5, and initial feed pH of 1.53.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.12
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• pp.1701-1711
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• 2012

Okinawan Awamori is produced by fermenting steamed indica rice with black mold, yeast, and water. Awamori-pressed lees is a by-product of the Awamori production process. Tofu lees is a by-product of the Tofu production process. This research consisted of two experiments conducted to elucidate whether or not dried Awamori-pressed lees and Tofu lees can be used as a mixed feed ingredient for raising female goats. In experiment 1, digestion trials were conducted to ascertain the nutritive values of dried Awamori-pressed lees and dried Tofu lees for goats. The digestible crude protein (DCP) and total digestible nutrients (TDN) contents of dried Awamori-pressed lees and Tofu lees were 22.5%, 22.5% (DCP), and 87.2%, 94.4% (TDN) respectively. In experiment 2, 18 female goats (Japanese Saanen${\times}$Nubian, three months old, body weight $15.4{\pm}0.53$ kg) were divided into three groups of six animals (control feed group (CFG), Awamori-pressed lees mixed feed group (AMFG), Tofu lees mixed feed group (TMFG)). The CFG control used feed containing 20% soybean meal as the main protein source, while the AMFG and TMFG treatments used feed mixed with 20% dried Awamori-pressed lees or dried Tofu lees. The groups were fed mixed feed (volume to provide 100 g/d increase in body weight) twice a day (10:00, 16:00). The klein grass hay and water was given ad libitum. The hay intake was measured at 08:00 and 16:00. Body weight and size measurements were taken once a month. At the end of the experiment, a blood sample was drawn from the jugular vein of each animal. The DCP and TDN intakes in AMFG and TMFG showed no significant difference to the CFG. Cumulative measurements of growth in body weight, withers height, chest depth, chest girth, and hip width over the 10 mo period in the AMFG and TMFG were similar to the CFG. By contrast, cumulative growth in body length and hip height in the AMFG and TMFG tended to be larger than the CFG. Cumulative growth in chest width in the AMFG was significantly larger (p<0.05) than the CFG. Blood parameter values were similar to those in normal goats reported by other scientists. The coats of the AMFG and TMFG animals looked shinier than the animals in the CFG. The results demonstrate that dried Awamori-pressed lees and Tofu lees can be used as a feed ingredient for the raising female goats.

• Journal of Animal Environmental Science
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• v.15 no.2
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• pp.115-130
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• 2009

Three experiments on the addition of Porous Calcium Silicate (PCS) to broiler feed were conducted at different time periods in the same house. Each treatment had 4 replicates with 12 chicks in each treatment. Weight gain and feed intake were higher ($P{\le}0.05$) in the control groups. Feed conversions' were better ($P{\le}0.05$) in the PCS group, 3.0% PCS and 20 mesh size of PCS than the control group from 21 to 49 days, and for the overall period. $NH_3$ and $H_2S$. gas production were decreased ($P{\le}0.05$) when zeolite was added in broiler feeds. 1.5% or 3.0% PCS in broiler feed was better ($P{\le}0.05$) than the 4% PCS. More than 90 mesh size PCS was better ($P{\le}0.05$) in controlling $CO_2$ production in the 5th period than the 20 or 50 mesh size or control groups. The control and PCS groups produced more flies ($P{\le}0.05$) than zeolite group during the 2nd and 3rd weeks. The 3.0% or 4.5% PCS or 50 or 90 mesh size of PCS in broiler feed produced more flies than the 20 mesh size or control groups although 50 or 90 mesh size of PCS during 5th week tended to have lower fly production than the 20 mesh size of PCS and control group.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.E
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• pp.47-57
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• 2000

This study focuses on the investigation of the effects of windspeed and particle size on the dust control characteristics inside a test dome built in the Port of Inchon to reduce the fugitive dust originating from the handling of animal feed stuff in the open pile area. The flow field inside the test dome and the trajectories of the particles were calculated using a commercial CFD code, FLUENT, assuming that the animal feed stuff handling activity took place inside the test dome. It was found from the simulation results that high windspeed and small particle size give rise to the increase in both the escaped fraction and the suspended fraction of the particles emitted from the animal feed stuff handing activity. Here, high escaped fraction represents the high possibility of fugitive dust problem outside the test dome, whereas high suspended fraction means the high possibility of severe dust pollution inside the test dome. Ore simulation results clearly show that the existing test dome was not designed properly to meet the proposed goal, low escaped fraction and low suspended fraction. Hence, we suggest the need of an efficient ventilation system inside the dome to control the dust.

• Publications of The Korean Astronomical Society
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• v.27 no.3
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• pp.87-93
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• 2012

A low-dispersion fiber feed Littrow-mounted grating spectrometer for education was designed and fabricated. The dispersion element is a reflective type blazed grating Edmundoptics NT 46-075 (spatial frequency 600 lines/mm, dimension $30mm{\times}30mm$, blazed angle 8.6 degree). The optical fiber coupler module for optical guiding from telescope to spectrometer is composed of a multi-mode FC connector - FC connector optical fiber patch cord (core/cladding diameter $50{\mu}m/125{\mu}m$) and two 1.25" throw-tube couplers. The lens for collimating and imaging is a general purpose focal length 50 mm camera lens (f/1.8). The device for optical path control is a rectangular prism (size $25mm{\times}25mm$). The imaging camera sensor is a Meade DSI Pro 2 CCD sensor (black and white, $752{\times}582$ pixels and pixel size $8.3{\mu}m{\times}8.6{\mu}m$). Softwares for data logging and analysis consist of Meade Autostar Suite, NIH imagej and Vernier Logger Pro 3. The wavelength coverage range of the spectrometer is 205 nm at central wavelength 550 nm. The wavelength resolution is 1.7 nm.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.12
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• pp.1717-1725
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• 2000

The objective was to determine the relationship between feed intake levels and patterns, and growth performance and body composition of barrows and gilts using automatic feed intake recording equipment (F.I.R.E.). This system records the time of visits to the feeder and the duration and size of meals for individual animals housed in groups. Ninety-six crossbred pigs were grown from $33.4{\pm}0.51$ to $109.7{\pm}1.39kg$ live weight over a 13-week period. Eight mixed-sex groups of 12 pigs were used and 4 dietary treatments were compared giving 2 pens per treatment. The dietary treatments consisted of corn-soybean meal diets with differing protein levels which ranged from 14.7% to 19% between 30 to 55 kg, from 13.3% to 16.9% between 56 and 85 kg, and from 12.3% to 16.8% for the remainder of the study. Animals were ultrasonically scanned to measure loin-eye area and backfat thickness to estimate carcass fat-free lean content at the beginning and end of the study. Barrows had higher daily feed intake than gilts (2.67 vs. 2.46 kg resp. p<0.05) which was the result of a longer feeder occupation time per visit (4.77 vs. 4.54 min, resp. p<0.05), higher feed consumption rates (30.4 vs. 29.0 g/min, resp. p<0.05), and higher feed intakes per visit (136.9 vs. 126.8 g, resp. p<0.01). Gilts had less backfat and greater loin-eye area than barrows (p<0.05). Diet had no significant effect on growth performance and had limited impact on feeding patterns. Body weight showed high correlations with ADG (r=0.74), feed intake per visit (r=0.51) and feed consumption rate (r=0.69). Positive correlation were also found between daily feed intake and feed intake per visit (r=0.45), feeder occupation time per day (r=0.56), and feed consumption rate (r=0.55), and between daily feed intake and backfat thickness (r=0.32) and feed consumption rate and loin-eye area (r=0.32). There were negative correlations between number of feeder visit per day and daily feed intake (r=-0.54), and between feed intake per visit and number of feeder visits per day (r=-0.43). However, correlations between feed intake traits and carcass traits were generally low. Visits to the feeder were greatest during the morning (0700 to 1100 h) and lowest during the evening and nighttime. These results highlight limited variation among the sexes in feeding patterns and suggest important relationships between feeding behavior and feed intake.