• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2208-2209
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• 2011

In this paper, the contactless power transfer using inductive power collector in order to apply to the vehicle such as the electric railway vehicle system is suggested and some ideas for power collector design to improve the power transfer performance are presented. This paper was presented for the transfer characteristic of power from input to output by resonance converter.

• Journal of Powder Materials
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• v.5 no.4
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• pp.324-328
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• 1998

This paper is aimed to study the computer simulation of sintering process for ceramics by Monte Carlo and molecular dynamics methods. Plural mechanisms of mass transfer were designed in the MC simulation of sintering process for micron size particles; the transfer of pore lattices for shrinkage and the transfer of solid lattices for grain growth ran in the calculation arrays. The MD simulation was performed in the case of nano size particles of ionic ceramics and showed the characteristic features in sintering process at atomic levels. The MC and MD simulations for sintering process are useful for microstructural design for ceramics.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1447-1451
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• 2004

The laminar impinging jet thermal fields were investigated with or without magnetic fields. The transient phenomenon from steady to unsteady flow was founded at specific Reynolds number ranges. In unsteady flow region, the magnetic fields make flow stable. So the characteristics of heat transfer at impingement wall are changed

• Transactions of the Korean Society of Mechanical Engineers
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• v.13 no.5
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• pp.1032-1043
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• 1989

The heat transfer characteristics of the drag reducing polymer solutions are investigated experimentally in the thermal entrance region of circular tube flows. Fluids used in experiments are the aqueous solutions of high molecular polymer, polyacrylamide Separan AP-273 and the range of polymer concentrations is from 20 to 1000 wppm. Two stainless steel tubes with inside diameter 8.5mm(L/D=712) and 10.3mm(L/D=1160) are used for the heat transfer flow loops. The flow loop is set up to measure friction factors and heat transfer coefficients of test sections in two different modes; the recirculating flow system and once-through flow system. The test tubes are heated directly by electricity to apply the constant heat flux boundary conditions to the wall. Three different types of adaptors are used to observe the effects of the upstream flow conditions of the heat transfer test sections. The viscosity and characteristic relaxation time of the test fluids circulating in the flow system are measured by the capillary tube viscometer and falling ball viscometer at regular time intervals. The installed adaptors exhibit slight effect on the entrance heat transfer of Newtonian fluid. However, no noticeable effects are observed for the entrance heat transfer of the drag reducing fluids. The order of magnitude of the thermal entrance lengths of the drag reducing fluids which follow the minimum friction asymptote is much longer than that of Newtonian fluids in turbulent flows. A new dimensionless parameter, the viscoelastic Graetz number, is defined and all the experimental data are recasted in terms of the viscoelastic Graetz number. The local Nusselt number of the viscoelastic fluids is represented as a function of flow behavior index n and the viscoelastic Graetz number. As degradation continues the viscosity and the characteristic relaxation time of the testing fluids decrease. Weissenberg number defined by the relaxation time and D/V appears to be a proper dimensionless parameter in describing degradation effects on heat transfer of the viscoelastic fluids.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.3
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• pp.62-68
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• 2007

The increasing use of power electronic equipment in distribution system has been the reason for the greater concern about a harmonic in recent time. Therefore, it is necessary for measurement and modelling to analyze a harmonic level and a transfer characteristic in distribution system. In this paper, the Point of Common Coupling (PCC) is selected to analyze harmonic characteristic of distribution system by IEC 61000-3-6. Harmonic voltage and orient were measured at the PCC of real distribution system Harmonic distribution, nonlinear load component and Total Harmonic Distortion(THD) were verified. The effective and accurate modelling of real distribution system were proved through a analysis of harmonic impedance, voltage and current under steady-state. Harmonic transfer characteristic were investigated through a analysis of harmonic voltage and current under harmonic current source.

• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.215-217
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• 2004

This paper shows the analysis of the inductive power transfer system in conjunction with series resonant converter operating variable high frequency. Of particular interest is the sensitivity of the complete system to variations in operational frequency and parameters. In inductive power transfer system, electrical power is transferred from a primary winding in the form of a coil or track, to one or more isolated pick-up coils that may relative to the primary. The ability to transmit power without contact enables high reliability and easy maintenance that allows inductive power transfer system to be implemented in hostile environments. This technology has found application in many fields such as electric vehicles, PRT(Personal Rapid Transit) etc. The coupling between the primary and secondary is then presented to include the effects of parameter and operational frequency variation.

• Journal of Distribution Science
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• v.12 no.1
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• pp.35-46
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• 2014

Purpose - This Study aims to promote technology transfer commercialization and ultimately make contribution towards enhancement of the success rate of commercialization of technology transfer at national level by deducing the factors that impart influence on the negotiation at the time of technology trading between the seller and buyer of technology of public research institutions subjected to transfer and sales. Research design, data and methodology - This Study deduced 5 research hypotheses through preceding researches related to technology transfer commercialization related technology marketing for technology trading negotiation. This Study was conducted by verifying the hypotheses through multiple regression analysis. Results - As the result of the Study, the research hypothesis H1, 'Promotion of commercialization of technology transfer trading will be affected in accordance with the innate characteristic factors of the technology', and H5, 'Promotion of commercialization of technology transfer trading will be affected in accordance with the mutual factors of the parties of the technology trading', among the 5 research hypotheses were chosen. Conclusions - It was found that the technology seller must be able to demonstrate technological value of the technology being sold in order to successfully conclude technology transfer trading negotiation and mutual understanding and harmonious communication between the parties.

• Journal of Environmental Science International
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• v.22 no.4
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• pp.415-424
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• 2013

In this paper, time series of soil moisture were measured for a steep forest hillslope to model and understand distinct hydrological behaviours along two different transects. The transfer function analysis was presented to characterize temporal response patterns of soil moisture for rainfall events. The rainfall is a main driver of soil moisture variation, and its stochastic characteristic was properly treated prior to the transfer function delineation between rainfall and soil moisture measurements. Using field measurements for two transects during the rainy season in 2007 obtained from the Bumrunsa hillslope located in the Sulmachun watershed, a systematic transfer functional modeling was performed to configure the relationships between rainfall and soil moisture responses. The analysis indicated the spatial variation pattern of hillslope hydrological processes, which can be explained by the relative contribution of vertical, lateral and return flows and the impact of transect topography.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.646-649
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• 2008

This study deals with mechanism of relay operation and modeling of transfer function between impact force and sound pressure due to the impact force in order to reduce relay noise. A collision between a moving-contact and fix-contact produces impact noise. Therefore impact noise of relay is determined by not only excitation force but also transfer function from impact force to noise. In this study, we find mechanism of relay operation, make impact force model and measure characteristic of relay noise. And also we find transfer function of relay noise.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.359-362
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• 2006

Infra-red thermography was conducted to understand a heat transfer characteristic on a surface protruded to a supersonic flowfield. Surface temperature distribution was obtained under the constant heat flux condition with a infra-red camera and the convective heat transfer coefficient distribution was calculated. Finally, two dimensional distribution of heat transfer coefficient on a surface around a cylinder body was derived.