• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1820-1823
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• 2003

A high speed feeding type laser cutting M/C is developed for precise cutting of sheet metal. This paper has been carried out to obtain cutting characteristics and optimal cutting conditions of the developed high speed feeding type laser cutting M/C by a design of experiments. Cutting speed. laser power. laser duty and gas pressure are control factors for the surface roughness. The major factors affecting the surface roughness and the optimum cutting conditions are studied with minimum experiments using Taguchi method.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.326-333
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• 2004

This paper presents the structural characteristics analysis of a high-speed horizontal machining center with spindle speed of 50, 000rpm and feedrate of 120m/min. The spindle system is designed based on the built-in motor, angular contact ceramic ball bearings, oil-air lubrication and oil-jacket cooling method. The X-axis and Y-axis feeding systems are composed of the linear motor and linear motion guides, and the Z-axis feeding system is composed of the servo-motor, ball screw and linear motion guide. The structural analysis model of the high-speed horizontal machining center is constructed by the finite element method, and the validity of structural design is estimated based on the structural deformation of the high-speed horizontal machining center and spindle nose caused by the gravity and inertia forces.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.608-611
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• 2005

As the optical communication industry is developed, the demand of optical communication part is increasing. $ZrO_2$ ceramic ferrule is very important part which can determines the transmission efficiency and information quality to connect the optical fibers. In general $ZrO_2$ ceramic ferrule is manufactured by grinding process because the demands precision is very high. For the precision grinding machining, it is very important that the error of feeding system is improved. Therefore, we estimated the dynamic characteristics in feeding system of ultra precision co-axial grinding machining system. Then, we performed the machining characteristics experiment.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.5
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• pp.655-667
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• 2001

This experiment was conducted to investigate the effect of feeding a low CP diet supplemented with synthetic amino acids on performance, nutrient utilization and carcass characteristics of finishing pigs fed under a three-phase feeding regimen. Ninety-six finishing pigs (Landrace$\times$Large White$\times$Duroc), $55.75kg{\pm}0.65$ of initial body weight, were blocked by weight and sex and allotted to four dietary treatments in a randomized block design. There were six pens per treatment and four pigs per pen. Pigs were fed a 16%-14%-12% CP (for phase I-II-III, respectively), sequence of diets. Dietary treatments were 1) Control, 2) Con+L (a sequence of diets reduced in CP by l percentage unit with lysine (L) supplementation, 3) Con+LMT (a sequence of diets reduced in CP by 2 percentage unit with LYS, methionine (MET) and threonine (THE) supplementation) and 4) Con+LMTT (a sequence of diets reduced in CP by 3 percentage unit with LYS, MET, THR and tryptophan (TRP) supplementation). The finishing period (55 to 105 kg) was divided into three phases (55 to 72 kg, 72 to 90 kg and 90 to 105 kg). Pigs fed either the control or Con+L diet grew faster (p<0.05) than pigs fed the Con-LMT or Con+LMTT diet. There was no difference in ADFI among dietary treatments. Phosphorus (P) digestibility was lowest in the control group and highest in the Con+LMTT group (p<0.05). Within each phase, no significant differences in dry matter (DM) and CP digestibilities were found. Although some amino acid digestibilities were affected by dietary treatments, digestibilities of essential amino acids (EAA), non-essential amino acids (NEAA) and total amino acid were not significantly influenced by dietary treatments. For the entire experiment periods, Con+L, Con+LMT and Con+LMTT treatments resulted in 13.4, 18.8 and 21.6% lower total N excretion compared with the control. Con+LMT and Con+LMTT treatments showed significantly lower BUN concentration compared with the control and Con+L treatment (p<0.05), but there was no significant difference in BUN concentration between pigs fed the control and Con+L treatment or between pigs fed Con+LMT and Con+LMTT treatments (p>0.05). Carcass length, backfat thickness and carcass grade were not significantly affected by dietary treatments (p>0.05). In conclusion, reducing dietary CP level by 1 percentage unit and supplementing only LYS at each phase could be a very beneficial feeding strategy for finishing pigs fed under a three phase feeding regimen in terms of both environmental and economical aspects.

• Korean Journal of Community Nutrition
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• v.3 no.1
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• pp.3-11
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• 1998

This study was aimed to evaluate any influence of environmental factors associated with feeding on infants' growth. One hundred infants(62 males and 38 females) aged 4-9 months were measured for length and were weighed. Their mothers were interviewed using questionnaires including general and environmental characteristics and maternal feeding attitude, ideal body habitus, infant's food behavior, and infant's food behavior, and infant's temperament. A further study was conducted on 29 infants at the time their ages reached 12 months. Their dietary intakes were assessed, and blood hemoglobin and serum ferritin concentrations were measured. Z-scores of weight-for-age(WAZ) and Z-scores of height-for-age(HAZ) of 4-9 month- old infants were not correlated with age, education level, income, weight, and height of their parents. Formula-fed infants had significantly lower WAZ and body mass index (BMI) than those of breast fed infants. WAZ was significantly correlated with maternal feeding attitude, but not with ideal body habitus, infant's food behavior or infant's temperament. WAZ of 12-months after birth because of supplementary foods introduced from 6 months of age. WAZ and BMI were positively correlated with blood hemoglobin concentration. Therefore, to ensure proper growth of infants, efforts should be given to postental factors such as breast-feeding, maternal feeding attitude, adequate iron status as well as prenatal factors. (Korean J Community Nutrition 3(1) : 3∼11, 1998)

• Food Science of Animal Resources
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• v.24 no.3
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• pp.221-224
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• 2004

The feeding group, composed of weaning pigs fed 3 mL of glucosamine derivatives, was compared for the carcass and quality characteristics with the unfeeding control group for 25∼70 days since they were born. The results were as follows; There were no significant differences in carcass weight and back-fat thickness between the feeding group and the unfeeding group although the feeding group had low ranges of standard error when compared to the control. Feeding group had higher incidence frequencies of A grade (42.7%) than the control (29.2%). The feeding group and unfeeding group had no significant differences in meat color, cooking loss, WBS, pH, WHC and purge loss. Results from this study showed that feeding GD had effect on the decrease the market weight and production of consist carcass weight, however, the feeding GD had no effect on pork quality during rearing times after weaning.

• Journal of Animal Science and Technology
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• v.63 no.5
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• pp.1086-1097
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• 2021

This study examined the impact of using total mixed ration (TMR) and concentrate on feed intake, daily gain, carcass yield grade, and carcass quality grade of Hanwoo steers and its subsequent economic efficiency. Thirty six 7-month-old Hanwoo steers were assigned to one of the four treatment groups, and each group was divided into three repeated pens, with each repeated pen comprising three steers. The treatment groups were: 1) separate feeding with commercial concentrate and forage (namely, SCF) for the entire experimental period; 2) TMR feeding for a growing period followed by SCF for the early and late fattening period (namely, TMRGSCF); 3) TMR feeding for growing and an early fattening period followed by SCF for the late fattening period (namely, TMREFSCF); and 4) TMR feeding for the entire experimental period (namely, TMRW). The results showed that the SCF treatment had significantly (p < 0.05) higher feed intake during the growing period than other treatments. In contrast, the total feed intake had little difference during early and late fattening as well as the whole period regardless of feeding strategies. Daily gain showed no difference during the growing period. However, it was significantly higher in SCF and TMREFSCF treatments for the early and late fattening period, respectively (p < 0.05). The daily gain during the total raising period is in the order of TMREFSCF > TMRGSCF > SCF > TMRW. Carcass characteristics, including carcass weight, loin eye muscle area, and carcass yield grade, did not significantly differ among different treatments. However, TMRW treatment, wherein TMR was fed for a long time, showed that the cold carcass weight was less compared with other treatments, but carcass yield grade was higher with thinner backfat. Backfat thickness was in the order of SCF > TMRGSCF > TMREFSCF > TMRW, showing that the thickness reduced with longer TMR feeding (p < 0.05). TMRGSCF, which numerically had a higher carcass quality grade, showed higher economic efficiency, whereas SCF showed low economic efficiency. In conclusion, it was more feasible to apply TMR strategy in the growing and early fattening period and then SCF for the early or late fattening period to improve carcass yield, quality grade, and economic efficiency.

• Parasites, Hosts and Diseases
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• v.61 no.2
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• pp.172-182
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• 2023

At the time of host attachment, ticks are very sensitive to histamine, but during rapid blood sucking they paradoxically require histamine. Using a rabbit model, we studied the effects of histamine and antihistamine during attachment and fast-feeding in different life stages of Haemaphysalis longicorns. We examined how they responded to histamine and antihistamine by analyzing the detachment rate, histology of feeding lesions, and post-feeding behavior. A significant difference (P<0.01) was found in the detachment rate between experimental and control treatments throughout the observation period. Ticks exhibited a higher detachment rate (30.1%) at 12 h after histamine application during attachment time and on antihistamine-treated skin (25.4%) at 96 h during fast-feeding. After feeding on histamine-treated rabbits, the fully engorged body weights of larvae and nymphs were 0.7±0.36 mg and 3.5±0.65 mg, respectively. An average increase in body weight of 0.6±0.05 mg and 3.2±0.30 mg was observed for larvae and nymphs compared to the respective control weights. Nymphs and adults engorged after antihistamine treatment had an average body weight of 1.3±0.54 mg and 54±0.81 mg, respectively. An average decrease in body weight was observed in antihistamine-treated H. longicornis compared with control nymphs (3.3±0.42 mg) and adults (174±1.78 mg). Skin biopsies were collected after treatment, and differential histopathological characteristics were found between the treatment and control groups. Tick-infested skin collected from rabbits in the antihistamine-treated group lacked erythrocytes in the feeding pool, indicating that antihistamine impaired tick fast-feeding stage.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.5
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• pp.648-654
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• 2004

This study was carried out to assess whether feeding of alcohol-fermented feeds (AFF) affects the nutritional metabolism and growth characteristics of Korean native steers. Ten steers were randomly assigned to one of two treatment groups. The dietary treatments were AFF (50% commercial beef cattle feed+30% alcohol-fermented soybean curd dregs+20% rice straw) and control (80% commercial beef cattle feed+20% rice straw). The change of serum metabolites and growth characteristics were measured every two months during the whole twelve months experimental period and the relationships between serum metabolites and growth characteristics were simultaneously analyzed. Four hours after feeding AFF, serum alcohol concentration reached its peak with a significantly higher value than that after control feeding (11.9 and 4.9 mg/dl, respectively). Serum glucose and inorganic phosphorus (IP) concentrations (63.1 and 8.4 mg/dl, respectively) of steers fed AFF were higher than those (56.6 and 7.0 mg/dl) fed the control diet. In both treatments, the serum glucose concentration rapidly increased when body weight (BW) of the steer reached about 600kg, while IP concentrations were rapidly diminished at that BW. Lower concentrations of both blood urea nitrogen (BUN) and cholesterol were observed in steers fed AFF up to 450 kg of BW. The IP concentration was correlated with concentrations of BUN, cholesterol and glucose in AFF fed cattle but not in the cattle fed control diets. Average daily gain was higher in steers fed AFF than steers fed control, particularly during the growing stage of cattle. These findings indicated a capability of AFF to improve BW gain of Korean native steers by decreased protein degradation as well as increased fat synthesis.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2004.11a
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• pp.131-139
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• 2004