• Journal of Institute of Control, Robotics and Systems
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• v.4 no.3
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• pp.315-320
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• 1998

In this paper, we present the PID control method for the controlling flow rate of highly complicated nonlinear Left Ventricular Assist Device(LVAD) with pneumatically driven mock circulatory system. Beat Rate (BR), Systole-Diastole Rate (SDR) and flow rate are used as the main variables of the LVAD system. System modeling is completed using the neural network with input variables (BR, SDR, their derivatives, actual flow) and an output valiable(actual flow). Then, as the basis of this model, we perform the simulation of PID control to predict the performance and tendency of the system and control the flow rate of LVAD system using the PID controller. The ability and effectiveness of identifying and controlling a LVAD system using the proposed algorithm will be demonstrated through computer simulation and experiments.

• JSTS:Journal of Semiconductor Technology and Science
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• v.10 no.1
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• pp.61-65
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• 2010

Threshold voltage is one of the most important factors in a device modeling. In this paper, analytical method to calculate threshold voltage for recessed channel (RC) MOSFETs is studied. If we know the fundamental parameter of device, such as radius, oxide thickness and doping concentration, threshold voltage can be obtained easily by using this model. The model predicts the threshold voltage which is the result of 2D numerical device simulation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.221-225
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• 2001

In the paper, we report on the DC and Thermal effect of the GaN based HFET. A physics-based a model was applied and found to be useful for predicting the DC performance and Thermal effect of the GaN based HFET by Various substrate. The performance of device on the sapphire substrates is found to be significantly improve compared with that of a device with an sapphire substrate. The peak drain current of the device achieved at HFET on the SiC substrate

• Journal of the Korean Society of Safety
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• v.24 no.4
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• pp.11-16
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• 2009

This research investigates contact angle of Linear Guide Way through a experimental result and theoretical analysis. Since last ten years, most of researchers who concerned with the precision machinery and semiconductor device production etc. so the researches about Linear Guide Way have been unnoticed. The precision machinery and semiconductor device production system has the principle which transfers the mechanical moving to accuracy position control. The Linear Guide Way system has the principle which transfers mechanical moving to accuracy position control is very important to improve performance of the precision machinery and semiconductor device production system. So, In this research, in order to improvement for producing Linear Guide Way, bearing loading analysis and contact angle change through Linear Guide Way theoretical analysis and bearing modeling. Through this study, we may expect that there will be more improvement for producing Linear Guide Way.

• Fire Science and Engineering
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• v.10 no.2
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• pp.28-39
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• 1996

A recently developed electro-thermal simulation methodology is used to analyze the behavior of a PWM(Pulse-Width-Modulated) voltage source inverter which uses IGBT(Insulated Gate Bipolar Transistor) as the switching devices. In the electro-thermal network simulation methdology, the simulator solves for the temperature distribution within the power semiconductor devices(IGBT electro-thermal model), control logic circuitry, the IGBT gate drivers, the thermal network component models for the power silicon chips, package, and heat sinks as well as the current and voltage within the electrical network. The thermal network describes the flow of heat form the chip surface through the package and heat sink and thus determines the evolution of the chip surface temperature used by the power semiconductor device models. The thermal component model for the device silicon chip, packages, and heat sink are developed by discretizing the nonlinear heat diffusion equation and are represented in component from so that the thermal component models for various package and heat sink can be readily connected to on another to form the thermal network.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.875-876
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• 2010

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.07a
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• pp.333-333
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.97-98
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• 2008

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.51-51
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• 2009

In this paper, we proposed GaN trench Static Induction Transistor(SIT). Because The compound semiconductor had superior thermal characteristics, GaN and SiC power devices is next generation power semiconductor devices. We carried out modeling of GaN SIT with 2-D device and process simulator. As a result of modeling, we obtained 340V breakdown voltage. The channel thickness was 3um and the channel doping concentration is 1e17cm-3. And we carried out thermal characteristics, too.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.12
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• pp.1018-1022
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• 2009

In this paper, we proposed GaN trench Static Induction Transistor(SIT). Because The compound semiconductor had superior thermal characteristics, GaN and SiC power devices is next generation power semiconductor devices. We carried out modeling of GaN SIT with 2-D device and process simulator. As a result of modeling, we obtained 340 V breakdown voltage. The channel thickness was 3 urn and the channel doping concentration is $1e17\;cm^{-3}$. And we carried out thermal characteristics, too.