• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1426-1430
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• 2009

AC AT feeding method consists return circuits of electric train inserting in parallel between trolly line and feeding line and connecting neutral line to rail and FPW. Due to increasing electric load at feeding system, collecting voltage of train and end voltage are going down. So to increase voltage between trolly line and rail, the usefulness of new autotransformer are considered which variation of short impedance and change of line voltage is simulated with modified winding ratio of autotransformer from 1:1 to variable tab.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.801-804
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• 2011

The concept design of joint part between propellant tank and feeding line for launch vehicle has been performed with the case study of oversea launch vehicles. we carried out, for the several configurations, numerical flow analyses to find the joint configuration which promises high flow uniformity at the outlet. There were a little difference in the numerical results, because the length of feeding lines are sufficiently long to stabilize the flow field.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.4
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• pp.11-16
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• 2006

Effects of an orifice on suppression of pressure oscillation in a fluid feeding line are investigated numerically through the installation of an orifice inside the feeding line. Based on linear acoustic theory, acoustic-damping effect of an orifice is emphasized in this study. When an orifice is installed at the node of pressure oscillation corresponding to the anti-node of velocity oscillation, damping capacity is maximized. On the other hand, the orifice installed at the anti-node of pressure oscillation has little damping capacity. As the blockage ratio and thickness of an orifice increase in the feeding line, damping factor increases. The feeding line with smaller diameter has more damping capacity, but damping factor increases more appreciably with blockage ratio in the feeding line with larger diameter.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1432-1438
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• 2011

This paper presents the simulation of traction power supply system for the evaluation of voltage drop in Kyungbu high speed line. This simulation is performed in circumstance of extended feeding through vicinity substation. Extended feeding should be considered from design of system. Therefore, voltage drop at extended feeding must be accepted against regulation. In this paper, voltage drop is evaluated under condition of extended feeding targeting section from Shinchungju and Pyungtaek S/S.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1169-1170
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• 2007

The primary objective of this paper is to examine the capacity of electrical transmission in electric railway according to the type of feeding system. Although supply capacity of railway substation are sufficient and there is no accident, due to the electrical transmission limit of feeding line the voltage breakdown may occur when large capacity of electric load at feeding line exist. So, using multi-port analysis model, we draw P-V curve due to feeding method, load, location and power factor of electric locomotive.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.577-583
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• 2013

We have analyzed influence of potential rise in negative bus, which caused by decrease of power feeding line insulation, upon protecting method of DC ground protection device which detecting potential rise between negative bus and ground in order to detect ground fault in the rubber wheel system. For this purpose, we proposed negative potential equation between negative bus and ground and calculated negative potential according to system condition changes by estimating power feeding line insulation changes in steel wheel system and rubber wheel system, and equalizing DC power feeding system when ground fault occurred. Also, in order to estimate negative potential of real system, we modeled the rubber wheel system, and simulated normal status, grounding fault occurrence and power feeding line insulation changes. In normal status, negative potential did not rise significantly regardless of vehicle operation. When ground fault occurred, negative potential rose up over 300V regardless of fault resistance. However, we also observed that negative potential rose when power feeding line insulation dropped down under $1M{\Omega}$. In conclusion, our result shows that in case of rubber wheel system unlike steel wheel system, relay will be prevented maloperation and insulation status observation can be ensured when ground over voltage relay will be set 200V ~ 300V.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.04a
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• pp.34-37
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• 2007

Propellant filling and holding test was carried out using liquid oxygen as a working fluid. The feeding line system has a filter at propellant tank outlet. Vaporization of liquid oxygen during holding after completion of filling and effect of vaporization to recirculation performance in this system was observed. Filling rate and pressure of tank ullage had the effect on state of liquid oxygen in feeding line. There was no geysering in feeding line during holding because of the position of filter.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.285-289
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• 2002

In this paper, microstrip line-probe feeding patch array antenna with center frequency 5.8㎓ is designed and manufactured. The microstrip line - probe feeding structure has broadband characteristic and be able to modify the array structure for improving antenna gain. In this result, microstrip line-probe feeding patch array antenna has 17.6% bandwidth and 8㏈i antenna gain, respectively.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1384-1389
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• 2004

The primary objective of this paper is to examine the capacity of electrical transmission in electric railway feeding system. Although supply capacity of railway substation are sufficient and there is no accident, due to the electrical transmission limit of feeding line the voltage breakdown may occur when large capacity of electric load at feeding line exist. So, using multi-port analysis model, we draw P-V curve due to the length of feeding line, load, location and power factor of electric locomotive. And through case study, compare measurement result and simulation result

• Journal of Veterinary Clinics
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• v.7 no.1
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• pp.403-406
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• 1990

The effects of enternal feeding on wound healing and intestinal movement in 30 gastrotomized dogs were investigated. The dogs were divided into enteral and parenteral feeding groups. Wound healing was evaluated with tensile strengh on the suture line 4 days after surgery and intestinal movement with the auscultation of borborygmus sound in the abdomen. There was no difference of the tensile strengh on the suture line between enternal and parenteral feeding groups. Borborygmus was auscultated in all dogs of the enteral feeding groups from day2 after surgery. It was thought that enteral feeding had no detrimental effect on wound healing as compared with the parenteral feeding and had good effect on the prevention of ileus in gastrotomized dogs.