• Asian-Australasian Journal of Animal Sciences
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• v.14 no.2
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• pp.231-236
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• 2001

This study was conducted to investigate the effect of supplemented enzyme complex on growth performance and nutrient digestibility in pigs weaned at 14 days of age. Eighty pigs ($4.02{\pm}0.11kg$ of average body weight) were allotted in a completely randomized block design. Treatments were as follows: 1) control (negative), 2) control (positive, $Kemzyme^{(R)}$), 3) 0.1%, 4) 0.2% and 5) 0.3% of newly developed enzyme complex. Each treatment has 4 replicates with 4 pigs per replicate. During phase I period (d 0 to 14), ADG and ADFI were numerically higher in pigs fed diets supplemented enzyme complex regardless of their inclusion levels compared to pigs fed control (negative) diet. Feed/gain (F/G) was also better in pigs fed enzyme complex diet than that of pigs fed control (negative) diet. In addition, with increasing the inclusion level of enzyme complex, ADG and ADFI were improved. However, there was no significant difference between treatment in all growth parameters. During phase II period (d 15 to 28), ADG, ADFI and F/G showed the same tendency as in phase I period. For overall period (d 0 to 28) ADG was highest in pigs fed diet included 0.2% enzyme complex in all treatments but not significantly different. During phase I period, the digestibilities of all nutrients did not showed any significant difference between treatments. However, pigs fed diet contained enzyme complex and positive control diet (Kemzyme) showed numerically higher nutrient digestibilities in all nutrients than pigs fed negative control diet. During phase II period, data were consistent with those observed in phase I period. Especially, the digestibility of phosphorus was significantly higher in pigs fed diets contained enzyme complex including phytase than pigs fed control (negative and positive) diets (p<0.05). For overall experimental period, fecal or ileal amino acid digestibility were not affected by dietary treatment. Enzyme complex newly developed and used in this study can be possibly recommended as a growth promoter when supplemented in diet for early weaned piglets.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.938-946
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• 2005

We study the firm's strategy to price its products and plan the spare parts manufacturing so as to maximize its profit and at the same time to fulfill its commitment to providing the customers with the key parts continuously over the relevant decision time horizon, i.e., the production plus warrantee period. To examine the research question, we developed and solved a two-stage optimal control theory model. Our analysis suggests that if the cost to produce the spare part during the warrantee period is more expensive than that during the production period, the firm should increase its sales price gradually throughout the production period to control its sales. In addition, during the production period it is optimal for the firm to produce the spare parts more than needed so that the overproduced spare parts can be used to partially meet the demand during the warrantee period. We conducted numerical analysis to investigate the sensitivity dynamics among key variables and parameters such as inventory holding cost, unit spare part production costs, part failure rate, and parameters in the demand function.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.402-406
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• 1989

Since the control parameters of classical PID controller are fixed for all control period, it is not easy to produce a desired transition phenomena. We incorporate an iterative learning scheme to the linear controller so that it has more flexibility and adaptation capability especially in the transition period. In this paper a hybrid type learning controller is proposed in which fixed linear controller guides learning at the beginning stage. Once a perfect learning is achieved, then the control action is performed by only the learning controller. A computer simulation result demonstrates better performance during transition time than that with only linear PD controller.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.681-685
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• 2000

A computer software was developed in our laboratory to automatically control the pigs environment by the image analysis system (IAS), which monitors and analyzes the pig's behavior and feeds the results back to the computer hardware. Three feeding trials were conducted with growing pigs ($L{\times}Y$) to test the effectiveness of the IAS under various seasons. In all three trials, the open-sided conventional pens with half-slatted floor were used as controls; for the IAS treatment, fully-slatted floors were used in the windowless pens. Experiment 1 was conducted in the winter for 30 d with 24 growing pigs. There were two treatments (Conventional vs. IAS), and three pens (replicates) per treatment. During the growing period, the feed efficiency was significantly (p<0.05) improved by the IAS. In addition, the pigs reared under the IAS during the growing period displayed better growth rate during the finishing period than did the pigs reared under the conventional conditions. Experiment 2 was conducted in the summer for 30 d with 24 growing pigs. The experimental design was the same as Experiment 1. During the finishing period, all the pigs were kept in conventional open-sided pens until their market weights to evaluate their carcass characteristics. During the growing period, the growth rate and feed efficiency of the pigs in the IAS was better than those of the control pigs. In addition, various carcass characteristics were significantly improved by the IAS rearing during the growing period. Experiment 3 was conducted with 30 growing pigs for 30 d in the spring. The experimental design was the same as Experiment 1. No difference was found in growing performance between the control and IAS pigs. It could be concluded that the IAS is effective in providing optimum conditions for the growing pigs in summer and winter seasons. In addition, providing an optimum environment during the growing period results in improved growth rate, feed efficiency, and carcass qualities for the finishing pigs.

• Journal of Nutrition and Health
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• v.14 no.3
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• pp.136-145
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• 1981

This study was designed to observe the effects of both control and atherogenic diets on the cholesterol and triglyceride (TG) in serum and liver of adult rats fed diets supplying two levels of dietary fat and two different sources of dietary protein in early life. For the first experimental period, the rats were assigned into the four diet groups: High fat, casein (HC); High fat, gluten (HG); Low fat, casein (LC): Low fat, gluten (LG). Each group was subdivided into control and atherogenic groups for the second experimental period. Cholesterol and TG were determined in serum and liver after 7 hr fasting. The body weight gain was greater in the rats of the casein groups than those of the gluten groups tut not influenced by the level of the dietary fat. The difference in body weight from the quality of dietary protein in the first period was not disappeared even after the second period. After the first period, higher serum cholesterol was observed in the rats fed either casein or high fat diets. With the second experimental diet, rats fed atherogenic diet showed higher serum cholesterol concentration but lower serum TG levels compared to those fed control diet, regardless the diets fed in the first period. Serum cholesterol level of the rats of both groups which had been fed high fat diets in early life was increased compared to those of the low fat diet groups. This effect was more pronounced with the atherogenic diet groups than control groups. However, no differences were found in serum cholesterol levels resulted from the different types of dietary protein fed in the first period. Serum TG concentration was not influenced by the quality of protein and level of fat in the diet but seemed to be mere affected by the amount of carbohyrates in the diet. Liver cholesterol per unit weight was greater in the gluten diet groups than in the casein groups but total cholesterol was higher in casein fed rats. There were no differences in liver TG among the groups.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.1
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• pp.1-5
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• 2020

Solar power generation systems require maximum power point tracking (MPPT) control to operate PV panels at their maximum power point (MPP). Most conventional MPPT algorithms are based on the slope-tracking concept. A typical slope-tracking method is the perturb and observe (P&O) algorithm. The P&O algorithm measures the current and voltage of a PV panel to find the operating point of the voltage at which the calculated power is maximized. However, the measurement error of the sensor causes irregularity in the calculation of the generated power and voltage control. This irregularity leads to the problem of not finding the correct MPP operating point. In this work, the power output of a PV panel based on the P&O algorithm is simulated by considering the insolation profiles from typical clear and cloudy weather conditions and the errors of current and voltage sensors. Simulation analysis suggests the optimal control period and perturbation voltage of MPPT to maximize its target efficiency under real weather conditions with sensor tolerance.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.2
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• pp.135-142
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• 2015

The Anti-Rolling Tank(ART) has an advantage over the other roll stabilizing devices, when ship is staying and working at one site of sea. An important design point of ART is the tank tuning, that is, matching the tank natural period to the ship's roll natural period. Since the load condition and consequently the roll natural period of ship is to be changed widely, the natural period of ART also has to be changed widely. In case of the existing U-tube type ART with a single layer duct, the tank natural period can be changed in a relatively narrow range. This paper suggests a new U-tube type ART system using a double layer duct to enable wide change of ART natural period. Through the roll experiments performed in regular beam waves for a box-type model ship, it is shown that the double layer duct ART has about two times wider period range and a better reducing effect of roll magnitude than the single layer duct ART.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.11
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• pp.1081-1085
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• 2010

In the wireless sensor networks, power consumption and interference among the nodes can be reduced by using the transmission power control. Because link quality is changed by spatial and temporal effect, link failures are frequently occurred. In order to adapt to link quality variation, existing transmission power control schemes broadcast beacon messages periodically to neighbor nodes and control the transmission power dynamically. However, it can effect on the time and energy overhead according to period of transmission power control. In this paper, the dynamic method of transmission power control by the link quality variation and variable period are proposed. When a link quality is unstable, the control duty cycle is reduced and the link quality is agilely maintained. In contrast, when link quality is stable, the control period is increased and control overhead is decreased.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3893-3898
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• 2012

In previous studies we predicted future trends in cancer incidence for each prefecture in order to plan cancer control. Those predictions, however, did not take into account the characteristics of each prefecture. We therefore used the results of age-period-cohort analysis of incidence and mortality data of Osaka, and estimated the incidence and mortality of cancers at all sites and selected sites. The results reflect the characteristics of Osaka, which has and is expected to have large number of patients with liver cancer. We believe our results to be useful for planning and evaluating cancer control activities in Osaka. It would be worthwhile to base the estimation of cancer incidence and mortality in each prefecture on each population-based cancer registry.

• Journal of Institute of Control, Robotics and Systems
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• v.8 no.6
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• pp.506-513
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• 2002

Distributed control systems(DCS) using fieldbus such as CAN have been applied to process systems but it is very difficult to design the DCS while guaranteeing the given end-to-end constraints such as precedence constraints, time constraints, and periods and priorities of tasks and messages. This paper presents a scheduling method to guarantee the given end-to-end constraints. The presented scheduling method is the integrated one considering both tasks executed in each node and messages transmitted via the network and is designed to be applied to a general DCS that has multiple loops with several types of constraints, where each loop consists of sensor nodes with multiple sensors, actuator nodes with multiple actuators and controller nodes with multiple tasks. An assignment method of the optimal period of each loop and a heuristic assignment rule of each message's priority are proposed and the integrated scheduling method is developed based on them.