• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.4
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• pp.275-283
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• 2021

In this study, a driver IC for an AC-powered LED that can be manufactured with a low voltage semiconductor process is designed and the performances of the driver IC were simulated. In order to manufacture a driver IC that operates directly at AC 220V, a semiconductor manufacturing process that satisfies a breakdown voltage of 500V or higher is required. A semiconductor manufacturing process for a high-voltage device requires a much higher manufacturing cost than a general semiconductor process for a low-voltage device. Therefore, the LED driver IC is designed in series so that it can be manufactured with semiconductor process technology that implements a low-voltage device. This makes it possible to divide and apply the voltage to each LED block even if the input voltage is high. The LED lighting circuit shows a power factor of 96% at 220V. In the pnp transistor circuit, a very high power factor of 99.7% can be obtained, and it shows a very stable operation regardless of the fluctuation of the input voltage.

• Journal of Service Research and Studies
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• v.11 no.2
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• pp.118-130
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• 2021

This study designs and validates a greenhouse complex environmental control algorithm with a multi-phase processing scheme that can combine and control actuators according to the degree of change in the greenhouse environment. The composite environmental control system is a system in which the complex environmental controller analyzes the information detected by sensors and operates appropriately actuators to maintain the crop growth environment. A composite environmental controller directs control devices driving actuators through a composite environmental control algorithm, which calculates the values necessary for the operation of the control devices. Most existing algorithms carry out control procedures on a single phase by iteration cycle, which can cause abnormal changes in the greenhouse environment due to errors in output. The proposed algorithm distributes control procedures over multiple phases: environmental control, environmental control, and device operation, and every iteration cycle, detects environmental changes in the environmental control phase first, and then combines control devices that can control the environment in the environmental control phase, and finally, performs the controls to derive the actuators in the device operation phase. The proposed algorithm is designed based on the analysis of the relationship between greenhouse environmental elements and control devices deriving actuators. According to verification analysis, the multi-phase processing scheme provides room to modify or supplement the setting value and enables the control devices to reflect changes in the associated environmental components.

• Journal of Navigation and Port Research
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• v.27 no.5
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• pp.505-511
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• 2003

In this paper, a driving amplifier stage with 1 Watt output has been designed and fabricated, which is operating at UHF band( 470 ∼ 806 MHz) for digital TV repeater. In the driving amplifier stage, preamplifier and 1 Watt unit amplifier are integrated by one electric substrate which is 2.53 in dielectric constant and 0.8 mm thickness. When the driving amplifier stage is flown by bias voltage of 28 V DC and current of 900 mA. it has the gain of more than 53.5 dB. the gain flatness of $\pm$0.5 dB and return loss of less than -15 dB in 470 ∼ 806 MHz. Also, when two signals at 2 MHz frequency interval are input port into the driving amplifier stage with 1 Watt output, it resulted in excellent characteristics to designed specification with showing intermodulation distortion characteristics of more than 48 dBc.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.3
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• pp.248-257
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• 2007

This paper presents the control system for driving myoelectric hand prosthesis according to myoelectric signal generated in the human muscle. A surface myoelectric sensor for measuring myoelectric signal is designed a skin interface and a processing circuit according to myoelectric signal output property. The control system consists of two controller for driving dual motor, torque sensor for measuring out torque of motor, slip sensor for detecting slip of torque. The experimental results proved the proposed control system.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.10
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• pp.45-51
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• 2009

The single phase buck-boost DC-AC inverter generates an alternating output voltage as the differential voltage of two DC-DC individual buck-boost converters. Two converters are driven with DC-biased and $180[^{\circ}]$ phase-shifted sinusoidal references. The peak value of the inverter alternating output voltage does not depend on the direct input voltage. In this paper, single phase buck-boost DC-AC inverter is designed and implemented on a prototype with digital controller using a microcontroller.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2005.04a
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• pp.229-232
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• 2005

본 논문에서는 다수의 로봇이 협동 제어 및 분산 제어를 목적으로 고안된 DARS 로봇의 마이크로 컨트롤러가 적은 메모리를 내장하여 영상 처리와 같은 많은 데이터를 처리하는 부분에서는 여러 제약이 생기는 문제점을 해결하기 위하여 DARS 로봇의 영상 처리 및 전송에 있어 데이터의 전송량을 줄이는 방법으로 영상 압축 방식을 사용하여 영상 압축 데이터의 전송을 구현하였다. 또한 DARS 로봇이 이동하면서 특정 미션의 수행이 가능하도록 배터리로 정전압을 공급하고, 물체를 감지하는데 있어 사각이 없이 $360^{\circ}$전 방향을 감지하도록 적외선 센서부를 설계하였다. DARS 로봇의 이동이 용이하도록 설계된 모터 구동부는 센서에 감지되는 물체의 거리에 따라 DARS 로봇이 속도를 정밀하게 가$\cdot$감속 제어를 하고, 마이컴 제어부는 카메라로부터 입력되 영상 신호를 압축 알고리즘을 이용하여 압축하고, 압축된 데이터를 컴퓨터로 전송한다. 컴퓨터에서는 입력된 영상을 Visual c++을 사용하여 화면 표시 및 DARS 로봇을 제어 할 수 있도록 구현하였다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.263-266
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• 2020

사용자에게 본인이 원하는 시점과 시각을 선택할 수 있도록 하는 자유시점 (Free Viewpoint) MPEG-I 과제를 통하여 3DOF, 3DOF+, 6DOF의 표준을 개발 중이다. 실사 영상의 자유시점 영상을 구현하는 방법으로는 깊이정보를 사용한 렌더링 기법을 사용하는데, 이를 실시간 재생할 수 있는 시스템은 개발되지 않았다. 본 논문에서는 PC 사양에서 NVIDIA 영상 코덱과 OpenGL사용하는 rtRVSlibrary를 바탕으로, 최대 8개의 HD급 다중 뷰 영상 입력 (컬러+깊이)을 자유 시점을 실시간 생성하여 디스플레이하는 재생기를 설계 및 개발하였다. 사용자는 원하는 시점으로 상하좌우앞뒤(회전)로 자유롭게 이동할 수 있으며, 계산양과 화질 효율성을 고려하여 디코딩한 입력영상 중에 두 개의 시점을 선별하는 알고리즘을 개발하여 실시간 동작 (25fps)을 검증하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.423-424
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• 2011

This paper has proposed a 920 MHz RF front-end for IEEE 802.15.4g SUN (Smart Utility Network) systems. The proposed 920 MHz RF front-end consists of a driver amplifier, a low noise amplifier, and a RF switch. In the TX mode, the driver amplifier has been designed as a single-ended topology to remove a transformer which causes a loss of the output power from the driver amplifier. In addition, a RF switch is located in the RX path not the TX path. In the RX mode, the proposed low noise amplifier can provide a differential output signal when a single-ended input signal has been applied to. A LC resonant circuit is used as both a load of the drive amplifier and a input matching circuit of the low noise amplifier, reducing the chip area. The proposed 920 MHz RF Front-end has been implemented in a 0.18-um CMOS technology. It consumes 3.6 mA in driver amplifier and 3.1 mA in low noise amplifier from a 1.8 V supply voltage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.10
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• pp.1899-1909
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• 2007

A cross-coupled charge pump with internal pumping capacitor, witch is advantages from a point of minimizing TFT-LCD driver IC module, is newly proposed in this paper. By using a NMOS and a PMOS diode connected to boosting node from VIN node, the pumping node is precharged to the same value each pumping node at start pumping operation. Since the lust-stage charge pump is designed differently from the other stage pumps, a back current of pumped charge from charge pumping node to input stage is prevented. As a pumping clock driver is located the font side of pumping capacitor, the driving capacity is improved by reducing a voltage drop of the pumping clock line from parasitic resistor. Finally, a layout area is decreased more compared with conventional cross-coupled charge pump by using a stack-MIM capacitors. A proposed charge pump for TFT-LCD driver IC is designed with $0.13{\mu}m$ triple-well DDI process, fabricated, and tested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.627-633
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• 2015

We designed of a LDO regulator with a OVP and UVLO protection function for a PMIC. Proposed LDO regulator circuit consists of a BGR reference circuit, an error amplifier and a power transistor and so on. The proposed LDO regulator is designed for low voltage input power protection. Proposed LDO circuit generated fixed 2.5 V from a supply of 3.3V. It was designed with 3.3 V power supply using a $0.35{\mu}m$ CMOS technology. SPICE simulation results showed that the proposed circuit provides 0.713 mV/V line regulation with output 2.5 V ~ 3.9 V and $8.35{\mu}V/mA$ load regulation with load current 0 mA to 40 mA.