• Asian-Australasian Journal of Animal Sciences
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• v.9 no.6
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• pp.643-646
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• 1996

Experiments were conducted to determine potassium (K) requirement of mule ducklings. One-day-old ducklings with equal number of both sexes were fed diets containing graded levels of K for three weeks. In experiment 1, corn-soybean meal diet (CP 18.7%, ME 2,890 kcal/kg, K 0.80%) was used. The addition of K (0.00, 0.10, 0.20, 0.30, 0.40%) to the diet by potassium carbonate resulted in a decrease in weight gain and feed efficiency with the group fed on basal diet having the best performance. This means that the existing K in the basal diet is adequate for the growth of ducklings. In experiment 2, low K corn-isolated soy protein diet (K, 0.19%) was used. The supplementation of K (0.00, 0.16, 0.32, 0.48, 0.64%) resulted in an increase in weight gain and feed efficiency with the control group having the lowest performance. The minimum K requirement was found to be 0.49% for both maximum growth and best feed efficiency as determined by using bent-stick model.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.10
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• pp.1450-1454
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• 2000

This study was conducted to examine the effects of dietary crude fiber levels on the growth and intestinal carbohydrases of goslings. Thirty-two, 2 week old female White Roman goslings were divided into four groups of 4 goslings with 2 replicates. Diets were isocaloric and isonitrogenous, containing 40, 80, 120 or 160 g/kg crude fiber. At the end of the 4 weeks of the experimental period, all goslings were sacrificed and the carbohydrases activities were measured. Feed intake was significantly higher in the 120 and 160 g/kg crude fiber groups over that in the 40 and 80 g/kg groups (p<0.05). The average daily gosling weight gain significantly increased with increasing crude fiber levels from 40 to 120 g/kg. However, both the daily gain and feed conversion of the 160 g/kg crude fiber diet group decreased significantly. Amylase, maltase and ${\alpha}-glucosidase$ activities in the duodenum significantly decreased as the dietary crude fiber level increased. The maltase and ${\alpha}-glucosidase$ activities in the jejunum-ileum showed a similar trend with those in the duodenum. By increasing the levels of crude fiber, cellulase activity in the caecum content significantly increased. There was, however, an adverse effect on the amylase activity.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.2
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• pp.124-132
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• 2014

In this paper, we implement a non-time-varying transfer function of the duty ratio to improve the control characteristics in a control system that Input voltage and the output voltage is varied, DC / DC converters for bi-directional charging. When control is performed with using controller gain of conventional design, characteristics of the control is varied to fluctuations of the input voltage. The proposed method is the equivalently removing method for duty ratio in entire control block, by voltage controller gain is changed for inverse of the duty ratio. The proposed non-time-varying duty ratio transfer function is applied to DC / DC converter for bi-directional charging. In this paper, feasibility and superiority is verified through PSIM simulations and experiments.

• Journal of Sensor Science and Technology
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• v.7 no.1
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• pp.17-22
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• 1998

A HARP (high-gain avalanche rushing amorphous photoconductor) image pickup tube using $4{\mu}m$ thick a-Se photoconductive film was fabricated and its characteristics were investigated. When the target voltage was increased more than 360 V, the signal current increases rapidly but the dark current of the tube was suppressed less than 3.2 nA up to the voltage of 490 V And the quantum efficiency of the target was about 4.3 at the electric field of $1.1{\times}10^{6}V/cm$ and the wavelength of 440 nm. Also the amplitude response of the HARP tube was 7.5% at 800 TV lines, and the decay lag was 3.4%.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.423-428
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• 2004

In this paper, STBC (Space Time Block Code) is applied to the WB system and frequency repeated diversity is used to get the 4-th order space time diversity gain. The performance of が STDB-OFDM system is analyzed by computer simulation. As a result of simulation, proposed W system can reduce the complexity that is introduced by increasing number of transmit antenna and show the same performance of 4 antennas with only using 2. Proposed system shows the enhancement of 7.1 dB compared to the general UWB OFDM and 1.9 dB compared to UWB STBC-OFDM.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.2
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• pp.345-354
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• 2024

In this paper, we propose a triple band WLAN antenna for Wi-Fi 6E band with DGS. The proposed antenna has the characteristics required frequency band and bandwidth by considering the interconnection of two strip lines and three areas on the ground place. The total substrate size is 31 mm (W) × 50 mm (L), thickness (h) 1.6 mm, and the dielectric constant is 4.4, which is made of 22 mm (W₆ + W₄ + W₅) × 43mm (L₁ + L₂ + L₃ + L₅) antenna size on the FR-4 substrate. From the fabrication and measurement results, bandwidths of 340 MHz (1.465 to 1.805 GHz) for 900 MHz band, 480 MHz (2.155 to 2.635 GHz) for 2.4 GHz band and 1950 MHz (4.975 to 6.925 GHz) for 5.0/6.0 GHz band were obtained on the basis of -10 dB. Also, gain and radiation pattern characteristics are measured and shown in the frequency triple band as required.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.85-91
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• 2010

The large amount of tissue culture medium (TCM), which contains some of the active secretory components of Korean wild ginseng (KWG; Panax ginseng) such as saponins, is usually discarded after harvest of KWG. The present study was aimed to investigate the efficacy of oral administration of the TCM-KWG on growth performance and diseases resistance in broiler chickens. A day old broiler chickens randomized in 6 groups (n = 60/groups) were administered orally with 0, 2, 4, 8, 16 and 32 mL/L TCMKWG through drinking water for 5 weeks and examined the change of weight gain, feed intake and blood components. Also, five weeks old broiler chickens (n = 15/groups) were challenged orally with Salmonella (S.) gallinarum and investigated the mortality in broiler chickens. An average weight gain and feed intake significantly didn't change in TCM-KWG administration groups as compared to control group. The concentration of calcium (Ca), phosphate (Pi) and potassium (K) in serum were increase by TCM-KWG administration in broiler chickens. We also found that oral administration of TCM-KWG through drinking water significantly reduced the mortality in broiler chickens experimentally infected with virulent S. gallinarum. The results of this study indicated that TCM-KWG administration may elevate the resistance on disease and improved the skeleton formation and body homeostasis of chickens, and TCM-KWG can be used as a cost-effective and environmentally alternative additives to control of the disease and growth.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.213-220
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• 2022

This study was conducted to investigate the effect of environmental factors such as water temperature and rearing density on the survival and growth of Litopenaeus vannamei under low salinity conditions. Overall, in the higher water temperature, the higher survival rate comes out and in the lower rearing density, the higher the survival rate does. In a study on feed efficiency, weight gain (WG) increased significantly as water temperature increased, and weight gain according to rearing density significantly decreased as rearing density increased. The growth rate of L. vannamei was faster when the water temperature was higher (water temperature 31℃) under low salinity conditions. In addition, in the evaluation of the growth rate according to the rearing density, it was confirmed that the growth rate was accelerated at a low rearinging density. It is believed that the results of this study will be usefully applied to the determination of the optimal rearinging density and breeding water temperature of L. vannamei in low salinity condition.

• Smart Structures and Systems
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• v.29 no.5
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• pp.661-675
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• 2022

In this paper, an electric vehicle drives with efficient control and low cost hardware using four quadrant DC converter with Permanent Magnet Direct Current (PMDC) motor fed by DC boost converter is presented. The main idea of this work is to improve the energy efficiency of the conversion chain of an electric vehicle by inserting a boost converter between the battery and the four quadrant-DC motor chopper assembly. Consequently, this method makes it possible to maintain the amplification gain of the 4 quadrant chopper constant regardless of the battery voltage drop and even in the presence of a fault in the battery. One of the most important control problems is control under heavy uncertainty conditions. The higher order sliding mode control technique is introduced for the adjustment of DC bus voltage and mechanical motor speed. To implement the proposed approach in the automotive field, experimental tests were carried out. The performances obtained show the usefulness of this system for a better energy management of an electric vehicle and an ideal control under different operating conditions and constraints, mostly at nominal operation, in the presence of a load torque, when reversing the direction of rotation of the motor speed and even in case of battery chamber failure. The whole system has been tested experimentally and its performance has been analyzed.

• Journal of Nutrition and Health
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• v.41 no.3
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• pp.199-205
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• 2008

The overall purpose of this study was to investigate the effects of level of isoflavones supplementation on bone metabolism in growing female rats. Forty-five rats divided into three groups; Control, l/2IF, and lIF. Serum osteocalcin and alkaline phosphatase (ALP) activity, urinary deoxypyridinoline (DPD) crosslinks value were measured to monitor bone formation and resorption at the ninth week after feeding. Hormones related to bone metabolism were determined, included parathyroid hormone (PTH) , calcitonin, estradiol, growth hormone and insulin-like growth factor I (IGF-I). The results of this study were as follows: the isoflavones intake level did not affect weight gain, mean food intake and food efficiency ratio. The serum concentration of osteocalcin and the activity ofALP were not significantly different by different levels of isoflavones supplementation. The urinary DPD crosslinks value was not significantly different by different levels ofisoflavones supplementation. There were no significant differences in serum PTH, estradiol and IGFI among all groups. However, calcitonin was shown significantly higher in the groups of lIF and l/2IF than control group. And growth hormone was shown significantly higher in the groups of lIF than control group. (Korean J Nutr 2008; 41(3): 199~205)