• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1853-1859
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• 2008

IGBT modules are designed for low loss, rugged for all environments and user friendly. Low on state saturation voltage with high switching speed is the primary concerns. In this paper selection of IGBT, module ratings and characteristics are discussed. The IGBT design topic of protection against over voltage and over current are covered. Emphasis on turn off switching, short circuit switching and necessary precautions are dealt. Selection of IGBT device, gate drive power, and its lay out considerations are covered in detail.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.747-748
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• 2006

In this paper, we describe photonic sensor interface and driver program based on SOPC(System on a programmable chip) platform. This platform uses device that has ARM922T processor and APEX FPGA area on a chip. As for driver program development, three different methods are tried such as simple firmware, real-time OS based program and embedded Linux based program, and results are compared for SoC implementation.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.478-480
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• 2009

This experiment implemented a laser projection system that used the 2D MEMS scanner as the driving method for the display device. The 2D MEMS scanner, which can scan the images horizontally and vertically, was applied to drive the projection system using the interlaced scanning method. The laser was directly modulated to implement the grayscale and the images were WVGA resolution quality.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.801-803
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• 2004

The current drive in an MOSFET is limited by the intrinsic channel resistance. All the other parasitic elements in a device structure playa significant role and degrade the device performance. These other resistances need to be less than $10{\%}-20{\%}$ of the channel resistance. To achieve the requirements, we should investigate the methodology of separation and quantification of those resistances. In this paper, we developed the extraction method of resistances using calibrated TCAD simulation. The resistance of the extension region is also partially determined by the formation of a surface accumulation region that forms under the gate in the tail region of the extension profile. This resistance is strongly affected by the abruptness of the extension profile because the steeper the profile is, the shorter this accumulation region will be.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.272-276
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• 2004

Great strides in organic light emitting device (OLED) technology have resulted in a number of commercial products. To continue this growth into large area displays, for example televisions, an understanding of the mechanisms that drive the OLED device efficiency and lifetime performance is critical. In this work, we consider maximizing the efficiency lifetime product based on phosphorescent OLED ($PHOLED^{TM}$) technology. We report green PHOLEDs with luminous efficiency of 82 cd/A, 5.7 V and 10,000 hours lifetime at 1,000 cd/$m^2$,red PHOLEDs with CIE of (0.67,0.33), 11 cd/A and 35,000 hours lifetime at 500 cd/$m^2$ and recent progress in blue demonstrating efficiencies of 18 cd/A at 200 cd/$m^2$.

• Proceedings of the KSME Conference
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• 2001.06c
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• pp.316-321
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• 2001

The optical storage device has recently experienced significant improvement, especially for the aspects of high capacity and fast transfer rate. However, it is necessary to study a new shape of air bearing surface for the rotary type actuator because the optical storage device has the lower access time than that of HDD (Hard Disk Drives). In this study, we proposed the air bearing shape by using SA (Simulated Annealing) algorithm which is very effective to achieve the global optimum instead of many local optimums. The objective of optimization is to minimize the deviation in flying height from a target value 100nm. In addition, the pitch and roll angle should be maintained within the operation limits.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.335-338
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• 2005

Starting with the development of environmentally friendly electric controlled engine, sensors have played an increasing role in automotive technology. Electric power steering (EPS) systems are more and more replacing hydraulic systems. To improve fuel economy, the power assistance is provided by an electric drive. In this paper, development of a unique torque sensor for EPS is introduced. A capacitive type torque sensor is concluded to be suitable for EPS because its output is accurate, linear and robust against the variance of temperature, and patents have not applied so much.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.42-46
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• 1993

This paper presents development of a pratical tool deflection compensation system in order to reduce the machining error by the tool deflection in the end-milling process. The system is a tool adapter which includes 2-axis force sensor for detecting tool deflection and 2-axis tool tilting device for adjusting tool position through computer interface in on-line process. In experiments, it is revealed that the force sensor applying parallel plate principle and strain gauge is proper to obtain dynamic process signal, and the tilting device using stepping motor and cam drive mechanism is suitable to have necessary action. By the system and control algorithm, it is possible to get precise machining surface profile without excessive machining error and overcut generated due to increased cutting force in more productive machining condition.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.7
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• pp.572-575
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• 2009

In this study, we proposed WLED(White-Light Emitting Diode) driver IC for mobile applications. This IC drove WLED for mobile applications with low input voltage and high efficiency by using boost converter. The device was designed by using boost converter applied current-mode control algorithm and provided PWM(Pulse Width Modulation) & analog dimming. Designed IC consisted of bias block, drive block, control block, protection block. We confirmed this device worked well through a application PCB (Printed Circuit Board) test.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.562-564
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• 1994

IGBT devices have the best features of both power MOSFETs and power bipolar transistors, i. e., efficient voltage gate drive requirements and high current density capability. The interaction of the IGBT with the load circuit can be described using the device model and the state equation of the load circuit. The protection circuit requirements are unique for the IGBT and can be examined using the model.