• 한국운동역학회지
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• 제12권2호
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• pp.393-405
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• 2002

When our body is immersed in water, we experience weightlessness. The degree of weightlessness that we experience varies depending on the proportion of the body immersed in water, being governed by the relationship between the weight of body and the buoyant force acting on the body. Human body during the performance of swimming in no exception to these influences. Swimmers body is subject to a time and position dependent force system. Even the magnitude of the buoyant force acting on the swimmers body at every given instant and the corresponding position of the CB change continuously. The findings of this study support the following conclusions. The buoyancy torque was the primary source of bodyroll exhibited by front crawl swimmers performing at distance pace, accounting for 88 % of the bodyroll. Faster swimmers used buoyancy more effectively to generate bodyroll, partially supporting the postulation that an effective use of buoyancy for bodyroll may reduce the generated hydrodynamic forces to be wasted in non-propulsive directions and maximize forward propulsion.

• 대한인간공학회지
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• 제18권3호
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• pp.141-152
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• 1999

In this paper, We performed the human body dynamic modelling for the realistic animation based on the dynamical behavior of human body, and designed controller for the effective control of complicate human dynamic model. The human body was simplified as a rigid body which consists of 18 actuated degrees of freedom for the real time computation. Complex human kinematic mechanism was regarded as a composition of 6 serial kinematic chains : left arm, right arm, support leg, free leg, body, and head. Based on the this kinematic analysis, dynamic model of human body was determined using Newton-Euler formulation recursively. The balance controller was designed in order to control the nonlinear dynamics model of human body. The effectiveness of designed controller was examined by the graphical simulation of human walking motion. The simulation results were compared with the model base control results. And it was demonstrated that, the balance controller showed better performance in mimicking the dynamic motion of human walking.

• 대한통합의학회지
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• 제12권2호
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• pp.11-23
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• 2024

Purpose : The purpose of this study was to investigate the effect of exercise using a suspension device (sling and total body resistance exercise; TRX) on physical functional performance and postural balance. Methods : An experimental study comparing 2 different suspension exercise was conducted on 16 healthy college students. 16 subjects were assigned to two groups. They were classified into 8 sling group and 8 TRX group. Miniplus was used to evaluate physical functional performance. In this study, isokinetic resistance mode was used to compare and analyze seven movement patterns. Biorescue was used to evaluate postural balance. The intervention exercises in this study are as follows. Standing lean forward (SLF) using a sling and TRX was performed 3 times a week for 3 weeks. The SLF was held for 10 seconds and then rested for 15 seconds, repeated a total of 10 times for 3 sets. Results : In the TRX group, significant increases were observed in physical functional performance (p<.05). Among the differences between groups, significant differences were confirmed on the front of the right arm, the back of the left arm, and the back of the right arm. In the sling group, significant increases were observed in left, right, front, and overall dynamic balance (p<.05). A significant increase in posterior dynamic balance was confirmed in the TRX group (p<.05). There was no significant difference between groups. Conclusion : Based on the results of this study, TRX was effective in improving physical functional performance, while the sling was effective in enhancing postural balance. However, confirming the effectiveness of slings and TRX in the relationship between physical functional performance and postural balance proved inadequate. Therefore, additional research should be conducted to verify the effects of suspension.

• Asian-Australasian Journal of Animal Sciences
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• 제6권1호
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• pp.61-66
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• 1993

Sixteen Korean native bulls weighing about 211 kg were randomly allotted to investigate the effect of different dietary calcium levels on performance. Feeding period was divided into growing period and fattening period for 180 days. Four calcium levels (0.44, 0.58, 0.72 and 0.86%) were used to each period. Bulls fed the diet containing 0.72% calcium had greater body weight gain and consumed more feed than bulls fed diets containing 0.44, 0.58 and 0.86% calcium and improved in feed efficiency. Bulls fed the diet containing 0.44% calcium were worst in performance. It can be concluded that Korean native bulls in growing and fattening period required no more than 0.72% calcium in diet that contained 0.55% phosphorus, and appeared that when ratio of calcium to phosphorus intake was 1.45, performance of Korean native bulls was most beneficial.

• 농업과학연구
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• 제50권2호
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• pp.155-164
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• 2023

A total of 16 sows (average parity = 3.5 ± 0.10, standard deviation = 2.05) and their newborn pigs (Duroc × [Landrace × Yorkshire], initial body weight 1.53 ± 0.07 kg) were used in a 21-day study. On day 3 of age, piglets along with their dam were divided into two groups: CON and TRT. CON group piglets did not receive any iron injection while, TRT group piglets received 200 mg of injectable iron (GleptoForte) in a single dose. The administration of iron at day-3 of birth improved weaning body weight and overall average daily gain in sucking piglets compared with their control counterparts. For blood criteria, injection of 200 mg of iron improved serum iron values and hematocrit and decreased total iron binding capacity (TIBC) during the day 21 period. In summary, 200 mg iron injection at birth resulted in greater growth performance and blood iron status. These results indicate that providing 200 mg of injectable iron is sufficient to optimize the growth performance and blood iron status of suckling piglets.

• Journal of Biosystems Engineering
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• 제26권6호
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• pp.563-570
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• 2001

To develop a stalk detaching system the effect of shape factor of red pepper affecting the performance of unfolding, arranging and cutting was analysed. The obtained results are as follows : By cutting experiment, it was found that the bending of stalk affected the cutting rate of stalk, and that the bending of body increased the amount of peppers that were expelled from the cutting guide by conveying brush. The ratios, 'bending length of a body/body length'and 'bending length of a stalk/stalk length', could be used as criteria far abnormality of body and stalk of peppers, respectively. As a result of experiment, it was concluded that mechanical treatment would be difficult for the peppers with indexes greater than 0.4 and 0.3 fur body bending and stack bending. respectively. So, these indexes were used as criteria for distinguishing abnormality from normality of peppers. In the unfolding unit, conveyance of peppers was impossible for both of normal and abnormal ones at the inclination angle of 10°, especially, at the frequency of 8.3 Hz peppers maintained stationary state. At the inclination angle of 20°, both of normal and abnormal peppers showed similar tendencies, but abnormal ones showed an accumulation trend gradually with increased feeding speed. In the arranging unit, conveyance of peppers was almost impossible for both of normal and abnormal ones at the inclination angle of 20°, showing almost no difference between the conveyances of normal and abnormal ones. In the case of the inclination angle of 30°, at the condition of the feeding speeds and frequency corresponding 0.06 m/s, 0.08 m/s and 8.3 Hz, respectively, the passing time of the abnormal peppers on the arranging plate increased rapidly.

• Animal Bioscience
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• 제35권2호
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• pp.247-259
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• 2022

Objective: This study was conducted to investigate the effects of age and diet forms on growth-development patterns, serum metabolism indicators, and parameters of body fat deposition in Cherry Valley ducks. Methods: According to the hatching age and initial weight, a total of 150 1-day-old male SM3 Cherry Valley ducks were randomly assigned to two diet forms (pellet vs powder form). Each treatment had with 5 replicates per treatment and 15 meat ducks per replicate. The study lasted 42 d, which was divided into two periods (1 to 21 vs 22 to 42 d). Results: Our results showed that compared with powder group, ducks in pellet group had greater growth performance during different period (p<0.05). The inflection point was 24 d and was not numerically affected by diet forms. Increasing age (42 vs 21 d) significantly increased the weight of body fat and hepatic fat metabolism related enzyme activities in ducks (p<0.05), meanwhile, increasing age (42 vs 21 d) improved serum metabolism indicators and decreased mRNA expression levels of fat metabolism-related genes in liver (p<0.05). Ducks fed different diets (pellet vs powder form) increased growth performance as well as the weight of body fat and improved serum metabolism indicators (p<0.05). In addition, interactions were found between age and diet forms on the levels of serum metabolism indicators in ducks (p<0.05). Conclusion: In conclusion, powder feed reduced growth performance of ducks, and the day of inflection point was 24 days old. Ducks with higher age or fed with pellet diet showed higher fat deposition. The effect of age and feed forms on body fat deposition might result from changes in the contents of serum metabolism indicators, key enzyme activity of lipid production, and hepatic gene expressions.

• Animal Bioscience
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• 제35권3호
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• pp.410-421
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• 2022

Objective: Two series of experiments were conducted to determine how the incremental levels of sodium metabisulfite (SMB)-treated fruit and vegetable discards (FVD) in diet of Hanwoo heifers and cows affect their performance and health. Methods: In Exp. 1, 36 Hanwoo heifers were stratified by age (13.3±0.83 mo) and initial body weight (305±19.7 kg), and divided randomly to one of three diets containing 0%, 10%, or 20% SMB-treated FVD (as-fed basis). The experiment lasted 110 d, including 20 d of adaptation. In Exp. 2, 24 multiparous Hanwoo cows were divided into three groups based on age (48.2±2.81 mo) and initial body condition score (2.64±0.33). Cows in each block were assigned randomly to one of three diets containing 0%, 11%, or 22% SMB-treated FVD (as-fed basis). The experiment lasted 80 d, including a 20-d adaptation period. In both experiments, SMB-treated FVD was used as a replacement for wet brewers grain in total mixed ration (TMR). Results: Growing heifers exhibited no differences in their daily feed intake (6.58±0.61 kg/d dry matter [DM]), average daily gain (0.60±0.07 kg/d), and body condition score when they consumed the incremental levels of SMB-treated FVD. Although most blood metabolites were unaffected by treatments, blood urea-N and β-hydroxybutyrate levels decreased linearly as the SMB-treated FVD level increased in TMR. Similar to Exp. 1, minor differences were found in daily feed intake (8.27±0.72 kg DM/d) and body condition score of Hanwoo cows. Most blood metabolites remained unaffected by treatments, but blood urea-N decreased as the SMB-treated FVD level in TMR increased. Conclusion: Our findings suggest that SMB-treated FVD could be safely incorporated into the diet of Hanwoo heifers and cows, potentially improving N-use efficiency in the body while not impairing performance or health.

• Animal Bioscience
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• 제36권5호
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• pp.776-784
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• 2023

Objective: This experiment was conducted to evaluate the inclusion of dietary nontoxic sulfur (NTS) on growth performance, immune response, sulfur amino acid composition and meat characteristics in growing-finishing pigs. Methods: A total of 140 crossbred pigs ([Yorkshire×Landrace]×Duroc) with an average body weight of 34.73±0.66 kg were used for the 12-week feeding trial. Experimental pigs were allotted to one of 5 treatments in 4 replicates of 7 pigs per pen in a randomized complete block (RCB) design. The experimental treatments were as follows (0%, 0.1%, 0.2%, and 0.4% NTS levels): i) Control, corn soybean meal (SBM)-based diet; ii) NTS 0.1, basal diet + NTS 0.1%; iii) NTS 0.2, basal diet + NTS 0.2%; iv) NTS 0.4, basal diet + NTS 0.4%. Results: Body weight increased linearly as dietary NTS levels increased up to 0.2% (linear; p = 0.04) in the early finishing phase (9 weeks). During the whole experimental period, body weight and average daily gain linearly increased as the dietary NTS level increased in the diet (linear; both p = 0.01), but quadratic responses in body weight and average daily gain were observed with the addition of NTS 0.4% (quadratic, both p = 0.01). In the late finishing period, the IgG concentration increased linearly (linear; p = 0.01) as the dietary NTS level increased up to 4%. In the finishing period, a linear response was observed as a dietary NTS level was added (linear; p = 0.03), and supplementation with 0.2% NTS resulted in a higher methionine content than the other treatments (quadratic; p = 0.01). NST 0.2% had a lower value of thiobarbituric acid reactive substances (quadratic; p = 0.01). Conclusion: Consequently, supplementation with dietary NTS up to 0.2% could improve growth performance, amino acid composition in hair and meat antioxidation capacity.

• 한국수산과학회지
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• 제56권5호
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• pp.734-740
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• 2023

The effect of feeding frequency on growth performance, body nutrient composition, and hematological parameters of juvenile chum salmon Oncorhynchus keta was investigated. The juveniles (10.9±0.3 g) were fed commercial feed for 30 days with feeding frequencies of 1, 2, 3, 4, or 5 meal (s)/day (n=2 tanks per treatment) in a recirculating aquaculture system (RAS). Fish were fed to satiation at each of the feeding frequencies. At the end of the feeding trial, final body weight, weight gain, and specific growth rate of fish fed 2 meals/day were significantly higher than those of fish fed 1 meal/day(P<0.05); however, no difference was detected among the other feeding frequencies. Daily feed intake significantly increased with increasing feeding frequency, whereas feed and protein utilization efficiencies continuously decreased with increase in the feeding frequency. Among the treatments, fish fed 1 meal/day showed the lowest value in whole-body lipid content and total protein concentration in plasma. Taken together, the optimal feeding frequency for growth performance and feed utilization efficiency in chum salmon juveniles reared in the RAS was determined to be 2 meals/day.