• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.360-362
• /
• 2004

In this paper, as the preceding research for development of intelligent electronic device for digital based substation automation system, we tried to select the most suitable digital filter by comparison of frequency response characteristic, performance of wanted frequency component extraction.

• Proceedings of the KIEE Conference
• /
• 2002.07a
• /
• pp.363-365
• /
• 2002

The characteristic responds of load respect to various disturbances which can usually be occurred on actual power system is very important to analyze performance and to improve load with high-technology. The disturbance power supply is designed to provide wide range of power to testing load. This device uses PLC technology to dynamic characteristic experiment and CVVF to change frequency. Also this instrument includes data acquisition system to obtain reliable data from experiment.

• Proceedings of the KIPE Conference
• /
• 1998.07a
• /
• pp.433-437
• /
• 1998

Equalize SOC of the cell which effect on the charge.discharge ability and the efficiency of the battery, through the charge.discharge characteristic test of the battery source, and develope the high efficiency charge.discharge system in the series HEV have a constant engine-generator output. For this, in this paper, establish the electrical model and the condition of high efficiency charge.discharge, and proposed the improvement method of charge.discharge characteristic in the battery source that consist of twenty Ni-MH cells connected serial/parallel

• Journal of the Korean Chemical Society
• /
• v.13 no.4
• /
• pp.325-332
• /
• 1969

An attempt has been made to investigate the nature of the characteristic darkening reaction occurring in the rice bran oil during the storage. Several pigments were separated by using column and thin layer chromatography of the pigments was made in the light of the knowledge of absorption spectral behavior. The presence of trace amount of iron and phytosteryl esters of ferulic acid (3-methoxy-4-hydroxy-cinnamic acid) was found to be responsible for the development of the characteristic color in rice bran oil. The model reactions with the ferulate, iron and fatty acids could be suggested the mechanism.

• Proceedings of the KIEE Conference
• /
• 2001.10a
• /
• pp.61-64
• /
• 2001

Demand for development of 154kV Less-Flammable Power transformer is now increasing greatly instead of a oil-immersed transformer for preventing disasters and Less-flammability of substations. The most important point in developing Less-flammable transformer is cooling system. This paper describes the study on cooling characteristic of Less-flammable transformer.

• Proceedings of the KSR Conference
• /
• 2009.05b
• /
• pp.323-337
• /
• 2009

This paper researched the adiabatic characteristic, safety and sound insulation characteristic of rolling stock window pane type and transition process of korean train vehicle window glass, and also including investigating a hereafter course of development. The window pane have provided the romantic feeling and the external scenery of train travel to the passenger in period of korea 110 year railway history. From the adiabatic viewpoint, this paper reviewed heat conductivity(U-value) and solar factor according to window pane type, including the safety and sound transmission loss of window pane.

• Journal of computational fluids engineering
• /
• v.13 no.1
• /
• pp.21-27
• /
• 2008

A numerical study for laminar flow in the entrance region of helical tubes for uniform inlet velocity conditions is carried out by means of the finite volume method to investigate the effects of Reynolds number, pitch and curvature ratio on the flow development. This results cover a curvature ratio range of 1/10$\sim$1/320, a pitch range of 0.0$\sim$3.2, and a Reynolds number range of 125$\sim$2000. It has been found that the curvature ratio does significantly effect on the angle of flow development, but the pitch and Reynolds number do not. The characteristic angle $\phi_c(=\phi/\sqrt{\delta})$, or the non-dimensional length $\overline{l}(=l\sqrt{\delta}cos(atan\lambda)/d)$ can be used to represent the flow development for uniform inlet velocity conditions. In uniform inlet velocity conditions, the growth of boundary layer delays the flow development attributed to centrifugal force, and in which conditions the amplitude of flow oscillations is smaller than that in parabolic inlet velocity conditions. If the pitch increases or if the curvature ratio or Reynolds number decreases, the minimum friction factor and the fully developed average friction factor normalized with the friction factor of a straight tube and the flow oscillations decrease.

• 한국전산유체공학회:학술대회논문집
• /
• 2004.10a
• /
• pp.177-180
• /
• 2004

The development of a tilting train with construction of electric line on the conventional railway is required for speed-up on the conventional railway with many curving sections. For development of tilting train, the study and development of the tilting system and tilting bogie having the different mechanism with a general high speed train will play a main role for improving the technology in the field of Korean railway The study and development of the pantograph tilting mechanism in order to keep a good contact behavior between a pantograph and a contact wire by tilting a pantograph on the opposite direction of the vehicle tilting direction. In this study, we analyzed the aerodynamic characteristic of a developing pantograph on the tilting train and obtained the contact force with catenary by aerodynamic lift force by the aerodynamic analysis. We also performed the numerical analysis for design the device controlling lift force on a pantograph. From the aerodynamic simulation and parameter study for a device to control the lift force, we will suggest the various shape and the optimal shape of it corresponding to a developing tilting pantograph. The Fluent software is used for the calculation of flow profile in this study.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.101-102
• /
• 2010

This paper represents about the characteristics of wind turbine industry of the west-south seashore of Leading Industry Development for Honam Economic Region. These projects have 8 R&D and 3 non R&D project. The period of these projects is from October 2009 to April 2012. The R&D projects are composed three bright prospect products (1) the base construction of MW off-shore wind turbine components and system with Outer-rotor type PMSG, (2) the Development of 3MW wind power system with accommodation of the west-south seashore, and (3) the development of hybrid wind turbine system with wind base construction. Also, the non-R&D projects are composed three parts with above three bright prospect products. Above two projects support the companies with characteristic of low speed wind turbine system. Other project supports the companies related to wind turbine with small and medium capacity of form 3 kW to 10kW.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.22 no.3
• /
• pp.134-142
• /
• 2018

Developing model to predict the characteristic of vented gas was vented through an orifice is presented. Simulations with models which were developed with assumptions considering heat transfer inside the vessel were conducted. Also, representative pressure and temperature were measured from experiments with the pressure vessel which is applicable to a propulsion system. Developed model were verified with comparison between calculations and experiments.