• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8
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• pp.1211-1218
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• 2019

Objective: The objective of this study was to determine the effects of age and gender (bull vs steer) on feeding behavior parameters in young beef cattle fed grass silage. Methods: The study was conducted on 180 young beef cattle at 7 to 18 mo of age. The experimental materials comprised 90 bulls produced by commercial crossing of Polish Holstein-Friesian cows with Charolais, Limousin and Hereford bulls (30 animals of each breed) and 90 steers of the same genotypes. The animals had ad libitum access to grass silage; the concentrate was fed separately, in feed stations. They received 28 g dry matter of concentrate per kg of metabolic body weight per day. Bunk visit data and silage intake for all experimental animals were recorded individually using the Roughage Intake Control system (5 feed bunks per 15 animals). Results: Age and gender (bull vs steer) exerted significant effects on the feeding behavior of young beef cattle. The frequency of bunk visits and meal frequency decreased, whereas the feeding rate of silage, and the average duration and size of a single meal increased with age (p<0.01). Bunk attendance and meal frequency were higher (p<0.01) in steers than in bulls (49.1 vs 37.4 visits/d, and 8.63 vs 7.99 meals/d, respectively). Daily feeding time was longer in steers than in bulls (102.3 vs 100.3 min/d, respectively), but the feeding rate of silage was lower in steers, and their meals were smaller in size and shorter in duration (p<0.01). Daily silage dry matter intake was higher (p<0.01) in bulls than in steers (4.62 vs 4.47 kg/d, respectively). Conclusion: The results of this study indicate that age and gender (bull vs steer) exerted significant effects on the feeding behavior of young beef cattle.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.1091-1097
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• 1991

A logical and systematic procedure to derive a mathematical model for magnetically levitation(maglev) systems with a combined lift and guidance is developed by using and graph. First, bond graph is constructed for the energy-feeding system with magnetic leakage flux. And, the overall maglev system in which lift and guidance dynamics are coupled is modeled by using the concept of multi-port field in bond notations. Finally, the LQG/LTR control systems are designed for single-input single-output and for multi-input multi-output maglev systems. In this paper, it has been shown that the bond graph is an excellent method for modeling multi-energy domain systems such as maglev systems and the multivariable control system is required to improve the performance of the maglev system with a combined lift and guidance.

• ETRI Journal
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• v.31 no.1
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• pp.74-76
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• 2009

A new feeding method for the circular polarization (CP) dielectric resonator antenna (DRA) is proposed in this letter. Two orthogonal modes (${TE^x}_{{\delta}11}$, ${TE^y}_{1{\delta}1$) of the rectangular DRA are excited by a $90^{\circ}$ phase difference of the differential and common modes currents of the proposed feeding structure. To demonstrate the good CP performance of the proposed method, a right-hand CP DRA for a global positioning system was designed. The impedance bandwidth of the proposed antenna for $S_{11}$ < -10 dB and 3 dB axial ratio bandwidth are about 5.4% and 1.95% at 1.57 GHz, respectively.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.26 no.2
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• pp.53-57
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• 2016

6H-SiC single crystals were grown by using a resistance heating system. It was recognized that the growth behavior was different according to the different growth temperatures. It was revealed that the temperatures at the source feeding and at the crystal growth position had to be controlled independently. In this report, the effect of growth temperature on the SiC crystal growth was discussed.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.11a
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• pp.315-318
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• 2020

Due to the increase in single-person households among the people who have companion animals, it is difficult to feed them to companion animals in the absence of the owner, so an automatic feeding machine was designed. In this paper, we propose an automatic feeding machine that has a drug distribution function as well as feeds using the Arduino platform. It is expected that in the proposed automatic feeding machine, users can access the food service through the website, and experience the convenient and extended food service function through the automatic dispensing system that combines the two materials.

• Journal of Electrical Engineering and Technology
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• v.8 no.1
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• pp.106-109
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• 2013

It is desirable and advantageous to feed parallel propulsion with induction motors by a single voltage source inverter. However, effects of deviation of the wheel diameters on motor current, rotor speed and torque should be also considered for parallel operation. In order to understand the behavior and characteristics, a simple simulation model is developed by using a commercial Matlab Simulink. From the results, it is clear to manage the diameter deviation of the wheels which are connected to traction motors.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.515-525
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• 1998

In this paper, for both transmission and reception with single antenna system of satellite communication, dual-frequency antennas which operate simultaneously at 12.5 GHz and at 14.25 GHz are designed, constructed and measured. Also by using dual feeding structure, the problems of single-fed dual-frequency antenna such as the separation of transmitting and receiving signals and single polarization, are solved. Microstrip patch as a radiation element of dual-fed dual-frequency antenna has width and length which are the resonance lengths of the corresponding frequencies for transmission and reception, respectively. The effects of the feed line on the other frequency feeding are minimized with the optimal matching scheme for the feed lines. For solving the space problems of dual-fed two-dimensional array antennas, microstrip-line and coaxial probe feedings are used for each frequency and a two-dimensional $2\times2$ array antenna was designed and measured their characteristics. The experimental results show that errors of resonance frequencies are less than 1.44%, the return losses are less than -21 dB and the isolations between two feeding ports are less than -21 dB. The characteristics of radiation patterns of dual frequency microstrip antenna are measured and evaluated. The directivities, sidelobe levels and cross polarizations are also measured and compared with the simulations. The results show some errors due to the misalignment of coaxial probe feeding.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.2
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• pp.342-348
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• 2015

In this paper, fuel cell power generation system that is being studied in recent railway field was applied to compensate for the voltage drop due to the load as driving electric vehicle. PSIM simulation program is to be used to implement the modeling of the electric railway for AC AT feeder system. For it, It was applied to the product-type single-phase PLL algorithm, step-down converter is controlled as power so as to have the fuelcell generation system. Based on it's result, a reactive power due to the catenary impedance in accordance with the current flowing is compensated as linked with fuelcell generation system which supplied the current to the power supply grid. and then its performance was confirmed that voltage compensation effect obtained at SubStation (SS), SubSectioning Post (SSP), Sectioning Post (SP).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.2
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• pp.228-235
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• 2011

In this paper, we propose a $4{\times}8$ SIW(Substrate Integrated Waveguide) slot array antenna for dual-polarized phased array system. The basic part of the array is a subarray comprising an vertical-polarization and horizontal-polarization. A vertical-polarization slotted SIW single-polarization linear array. Using SIW, A vertical polarization linear array consists of 8 uniform longitudinal slots and 4-way SIW feeding network. Using HMSIW, horizontal-polarization linear array consists of 8 slots and 4-way SIW feeding network.

• Design & Manufacturing
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• v.10 no.2
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• pp.39-43
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• 2016

Most of automobile parts manufactured through sheet metal forming are mass-produced by using press mold. In recent years, automation and speeding up of press lines have been expanding to maximize product productivity using a press die. The proportion of the moving time in the press line is high, and therefore requires high-speed and automated equipment for the moving process. In this paper, to provide the double-moving system can be the moving time reduction and increased productivity. Developed transport system consists of the material supply, the material feeding device and the PLC controller and the devices are positioned between each of the pressing process. In this paper, the double-moving system including developed units using a multi-axial single-acting through this reduced the C/T(cycle time) and improved the productivity.