• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.12a
• /
• pp.114-118
• /
• 2006

We investigated the transient electroluminescence (EL) and modulation characteristics of red organic light-emitting diodes (OLEDs), which consist with 4-(dicyanomethylene)-2-i -propyl-6-(1,1,7,7-tetramethyljulolidyl-9-cnyl)-4H-pyran (DCJTI) and rubrene doped into tris(8-hydroxyquinoline)aluminum ($Alq_3$). The transient EL waveforms showed two components, the overshooting peak and constant component, indicating that the excess amount of accumulated charges simultaneously recombine at the onset moment. This overshooting effect reduced the rise time of transient EL and enhanced the optical output of OLEDs when the pulse voltage applied to the device. We demonstrated that the red OLEDs could be use for the high-speed switching application by driving at more than 100 MHz and transmitting the video signals utilized as the electro-optical conversion device

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1727_1728
• /
• 2009

Nowadays DC-DC converter has been used widely in electronic production. It has a high requirement in wide input voltage, load variations, stability, providing a fast transient response and lower overshoot. However, it is not easy to be controlled because of its nonlinearity. In this paper, the nonlinear model of DC-DC converter is approximatedby four linear models and sub-controllers are designed by using the LMI guaranteeing the stability of the sub-systems at the same time. For the robust of the control system, an integral sliding mode control (ISMC) is applied together with LMI fuzzy controller. The proposed controller supports a fast and almost no overshooting transient response for the DC-DC converter control.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.1223-1225
• /
• 2003

By having the proposed circuit using a smaller one with a small reactor, the output voltage is boosted-up and improves the input of the current waveform. Therefore, we are able to follow the harmonics guidelines. Greater power and efficiency is obtained from the proposed circuit. This also reduces some switching loss and holds the overshooting by using the inverter of eliminated dead-time HPWM which is a non-linear impedance of the circuit to make up the diodes, the capacitance, and the reactor. We compared the conventional PWM inverter and proposed HPWM inverter.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.6
• /
• pp.659-665
• /
• 2023

The exciter of a ship generator adjusts the magnetic flux through excitation current control to maintain the output terminal voltage constant. The voltage controller inside the exciter typically uses a proportional integral control method. however, the response characteristics determined by the gain and time constant produce unwanted output owing to an inappropriate setting value that can reduce the quality and stability of power within the ship. In this study, a neural network circuit is learned using stable input/output data that can be obtained through the AC4A type exciter model provided by IEEE, and the simulation is performed by replacing the existing proportional integral control type voltage controller with the learned neural network circuit controller. Consequently, overshooting was improved by up to 9.63% compared with that of the previous model, and excellence in stable response characteristics was confirmed.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.47 no.4
• /
• pp.1-6
• /
• 2010

We can see the motion blur phenomenon on theedge of the moving picture when it moves in the LCDs. To reduce this phenomenon, we suggested a new over-deriving method, implemented on the board XUP Virtex-2 Pro Development System by using Virtex-2 Pro XUP XC2VP30 and improved the Motion Blur. In this method, we did not use additional parts except for a SDRAM. Hardware implementation for IP and data interface were handled in software. In this paper, we used the moving bar and the moving video image as a design model. We also showed that the afterimage was reduced and the vivid moving images was displayed. through this method.