• 한국생산제조학회지
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• 제22권3호
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• pp.380-387
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• 2013

In this study, two finite element (FE) models were developed to evaluate the thermal characteristics of a feeding axis of a CNC lathe. One was used for analysis of heat transfer to identify the temperature distribution of the feeding axis and then, the other was used for analysis of thermal deformation to evaluate its structural behavior based on the temperature distribution. The FE models were based on the test standard for the axial thermal displacement. The feeding velocity was composed of three steps: the ascending, constant, and descending velocities. Therefore, the heat generation and convection coefficient were calculated for each velocity and applied to the thermal FE model. The convection coefficient for the ball screw rotation was based on an experimental equation. The result of the analytical thermal displacement was compared with that of the experimental displacement to verify the finite element models.

• 한국가축번식학회지
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• 제10권1호
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• pp.49-57
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• 1986

Studies were conducted to investigate the relationship between hormone leveles and nutritional levels for improving performance of Cheju native cattle. In June 1984 a trial was initiated using 8 Cheju native calves after weaning, fed at two su, pp.ementary feeding levels (NRC 100% and 70%). The body weight, breedng performence, change in progesterone level during pregnancy and estrus cycle were evaluated. Mean body weight at 6 months of age was 155kg when fed 100% NRC ration but it was only 137kg when heifers received the 70% NRC ration. At 10, 15 and 20 months of age the body weight was 66, 160 and 115kg, respectively, showing that heifers fed the standard ration gained weight rapidly (P<0.01). Average size of the lefe ovary in the standard group was 2.1${\times}$1.6cm and right ovary was 2.6${\times}$1.8cm. However in the restricted feeding group the ovaries were found to be smaller. Diameter of graffian follicles showed a similar tendency to ovarian size in the two groups. The first oestrus in the standard feeding group a, pp.ared at 14.6 months when body weight was 265kg. Age at first calving was on average 28.9 months at a body weight of 436kg. On the other hand when heifers were fed the restricted ration the first oestrus a, pp.ared at 23.0 months at a body weight of 250kg. Average age at first calving was 38.9 months which was 10 months later than the average in the standard feeding group (P<0.01). In standard feeding group the progesterone level was 2.0ng/ml at two weeks after pregnancy and gradully increased up to 4 weeks and peaked at 18 weeks. This peak (6.4-6.5ng/ml) was maintained up to 24 weeks when progesterone level decreased until it reached 2.1ng/ml at the end of pregnancy. In the restricted group progesterone level up to 16 weeks followed a similar pattern to the standard group but there was a tendency in the restricted group to have lower progesterone levels(P<0.01). The standard and srstricted groups showed similar patterns of progesterone concentration during the oestrus cylce. There were no statistically significant differences in progesterone levels between standard and restricted groups but there was variation between induvidual animals.

• 농업과학연구
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• 제47권4호
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• pp.783-789
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• 2020

This study was conducted to evaluate growth performance of weaned pigs using diets based on ideal protein of the Korea swine feeding standard (KFS) and US the nutrient requirements of swine (NRC). A total of 96 weaned (initial body weight of 6.12 ± 1.21 kg) pigs were randomly allocated into 2 dietary groups with 12 pens per diet (4 pigs·pen-1) in a completely randomized design. The dietary treatments were corn and soybean meal-based diets formulated by the KFS and NRC nutrient requirements estimates for weaned pigs. Experimental diets were fed for 6 weeks in 2 phases feeding program based on age: 1) Phase 1 = week 1 to 3 (21 days); 2) Phase 2 = week 4 to 6 (21 days). During Phase 1 and 2, there were no differences (p > 0.05) for the initial and final body weights between the KFS and NRC groups. Additionally, the average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G : F) during overall experimental period were not different between the groups. In conclusion, weaned pigs fed the diet based on the KFS had a similar body weight and growth performance to those fed the diet based on the NRC. This suggests that the Korea swine feeding standard may be used for the diet formula of weaned pigs in Korea swine production compared with the US nutrient requirements of swine.

• 동아시아식생활학회지
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• 제7권4호
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• pp.468-474
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• 1997

To evaluate the effect of feeding time and high fat diet on weight gain and blood components in rats, the classification of groups were night(P.M. 8:00-next day A.M. 8:00), day(A.M. 8:00 P.M. 8:00) and ad-libitum(24 hours)group as feeding time. Each group has also 2 groups by fat level(high-fat diet, standard diet). Therefore, the 36 experimental animals were divided into 6 groups. The results of this study can be summarized as follows. Food intake of SA(standard diet / ad-libitum) and SN(standard diet/night) groups was significantly higher than the others, and HA(high fat diet /ad-libitum) and HD(high fat diet /day) groups was significantly lower than the others. Body weight gains of HN group and SA group were significantly higher than the others in 5 weeks. The blood contents of total cholesterol, triglyceride, protein and albumin were no significant difference among experimental groups, but the blood contents of glucose were higher in HN and SD groups than SN and HA groups. Accordingly, eating before asleep and high fat diet bring about one's overweight and abnormal blood concentration.

• 수산해양기술연구
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• 제58권2호
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• pp.121-129
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• 2022

Density and sound speed contrasts (g and h, respectively), and swimming angle were measured for sandfish (Arctoscopus japonicus) without swimbladder. The density contrast was measured by the volume displacement method while the sound speed contrast was measured by the acoustic measurements of travel time (time-of-flight method). The swimming angle was measured by dividing it into daytime, nighttime, daytime feeding and nighttime feeding. The g was 1.001 to 1.067 with an average (± standard deviation) of 1.032 (± 0.017), and the h was 1.007 to 1.022 with an average (± standard deviation) of 1.015 (± 0.003). The swimming angles (mean ± standard deviation) were 16.8 ± 10.3° during the daytime, 1.9 ± 12.3° during the nighttime, 30.2 ± 12.6° in the daytime feeding and 35.0 ± 13.2° in the nighttime feeding. These results will provide important parameters input to calculate theoretical scattering models for estimating the acoustic target strength of sandfish.

• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.635-638
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• 2003

Japanese Black cattle (Wagyu) are fed for a long period to produce high quality beef, however, extended feeding often causes inefficiency and greater environmental load mainly derived from their manure. The objectives of this study were to analyze changes in feeding length by listing breeding values (BVs) at calf markets and the relationships between BVs and carcass characteristics of 4,052 Japanese Black cattle, and to examine the feasibility of optimizing feeding length by referring to listed BVs. BV classes A, B, and C were defined based on BVs of cows in Shimane Prefecture as follows: an upper quarter of BVs was classified as A, a second quarter as B, and under the average as C. For cattle sold at calf markets in the first term of 1996, just before the start of BV listing, the feeding length of cattle with class B BVs for the beef marbling standard (BMS) was longer (p>0.05) than that of class A cattle. However, in the second term of 1996, just after the start of BV listing, the feeding length of class B cattle became shorter (p<0.001) than that of class A cattle. Then, the feeding lengths of both classes showed no significant differences. Feeding lengths of both class A and B BVs for carcass weight (CW) changed similarly to the corresponding BV classes for BMS. The analysis of the relationships among the listed BV classes and the actual carcass characteristics showed that class A cattle had a higher (p<0.001) BMS than class B cattle, and that the higher-class cattle had a heavier CW (p<0.05). On the basis of previous reports, the cattle, particularly those with lower genetic marbling ability, seem to only increase marbling at markedly low efficiency for a few months before slaughter. Therefore, the finding that carcass characteristics corresponded to their class of BVs suggests that an optimum feeding length based on listed BVs not only increases the efficiency of beef production, but also reduces the environmental load.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1997-2004
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• 2011

The $2{\times}25kv$ AT electric power feeding method in the A.C. electric train adopts the one-phase power feeding method as the standard due to a voltage phase difference, and the distance between the two neighboring substations is 50km due to voltage drop. The one-phase power feeding method makes the system operation feasible, while making it unfavorable for power supply. Moreover, railroad involves large-capacity single-phase load, and if it is expected to continue to rise, it is necessary to research on measures to stabilize the supply of power to railroad cars with the existing facilities. In this study, a parallel power feeding method between neighboring substations is proposed to stabilize the supply of electric power to electric railroad cars under the 2*25kv AT power feeding method and the loop current induced by voltage phase difference between the two neighboring substations during parallel power feeding is investigated.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.213-215
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• 1994

Poultry feeding systems are likely to change for increased efficiency of production. An experiment was conducted to compare the response of broilers to choice feeding of corn with a standard broiler ration. The treatments consisted of providing broiler feed as the only feed (SINGLE FEED) and access to corn as a choice to a complete broiler feed (CHOICE FEEDING). Weights and feed consumption were obtained at weekly intervals. Samples at the conclusion of the experiment were taken to determine the weight of abdominal fat. Results showed that there was no significant difference in term of liveweight between the two feeding regimes. However, birds given a choice of the broiler feed and corn had better feed efficiency which is reflected by the lower total feed intake. Corn intake was 23.1% of total feed intake in the choice fed birds. In term of carcass colour, birds fed corn as a choice was observed to have a deeper yellow skin colour than the birds fed with broiler feed only.

• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.185-195
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• 2015

Glucoamylase is an important industrial enzyme. Glucoamylase production by industrial Aspergillus niger strain featured with two major problems: (i) empirical substrate feeding methods deteriorating the fermentation performance; and (ii) the high raw materials cost limiting the economics of the glucoamylase product with delegated specification. In this study, we first proposed a novel three-stage varied-rate substrate feeding strategy for efficient glucoamylase production in a 5 L bioreactor using the standard feeding medium, by comparing the changing patterns of the important physiological parameters such as DO, OUR, RQ, etc., when using different substrate feeding strategies. With this strategy, the glucoamylase activity and productivity reached higher levels of 11,000 U/ml and 84.6 U/ml/h, respectively. The performance enhancement in this case was beneficial from the following results: DO and OUR could be controlled at the higher levels (30%, 43.83 mmol/l/h), while RQ was maintained at a stable/lower level of 0.60 simultaneously throughout the fed-batch phase. Based on this three-stage varied-rate substrate feeding strategy, we further evaluated the economics of using alternative carbon sources, attempting to reduce the raw materials cost. The results revealed that cornstarch hydrolysate could be considered as the best carbon source to replace the standard and expensive feeding medium. In this case, the production cost of the glucoamylase with delegated specification (5,000 U/ml) could be saved by more than 61% while the product quality be ensured simultaneously. The proposed strategy showed application potential in improving the economics of industrial glucoamylase production.

• Clinical and Experimental Pediatrics
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• 제53권1호
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• pp.7-13
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• 2010

Early nutritional support for preterm infants is critical because such support influences long-term outcome. Minimal enteral feeding should be initiated as soon as possible if an infant is stable and if feeding advancement is recommended as relevant to the clinical course. Maternal milk is the gold standard for enteral feeding, but fortification may be needed to achieve optimal growth in a rapidly growing premature infant. Erythromycin may aid in promoting gastrointestinal motility in cases that exhibit feeding intolerance. Selected preterm infants need vitamins, mineral supplements, and calorie enhancers to meet their nutritional needs. Despite all that is known about this topic, additional research is needed to guide postdischarge nutrition of preterm infants in order to maintain optimal growth and neurodevelopment.