• Title/Summary/Keyword: Current-steering

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High-Speed BiCMOS Comparator

  • Jirawath, Parnklang;Wanchana, Thongtungsai
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.510-510
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    • 2000
  • This paper introduces the design of BiCMOS latched comparator circuit for high-speed system application, which can be used in data conversion, instrumentation, communication system etc. By exploiting the advantage technology of the combination of both the bipolar transistor and the CMOS transistor devices. The comparator circuit includes an input stage that combines MOS sampling with a bipolar regenerative amplifier. The resistive load of conventional current-steering comparator is replaced by a load, which is made by a NMOS transistor. The advantage of design and PSPICE simulation of BiCMOS latched comparator are the circuit will obtain wide bandwidth with lowest power consumption at a single supply voltage. All the characteristics of the proposed BiCMOS latched comparator circuit is carried out by simulation program.

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The Changing Role of Government Research Institutes in Innovation Systems

  • Guinet, Jean
    • STI Policy Review
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    • v.1 no.1
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    • pp.63-92
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    • 2010
  • Recent years have seen an intensified discussion in many OECD countries about the role and mission of public research in the innovation system. This discussion takes place in quite specific national contexts, but should benefit from international experience. However, whereas voluminous literatures address the changing governance methods, organizational forms and missions of universities, much less attention has been devoted to developing a common understanding of the challenges faced by non-university public research institutions. The main goals of this paper is to contribute to clarifying the nature of these challenges, outlines possible policy answers and draws some implications for Korea. In the first section, the paper uses available internationally comparable indicators to review trends in the contribution of government research institutes (GRIs) to R&D and innovation activities. In the second section, the paper identifies the current major changes in the dynamics of innovation that may call for further adjustments in the positioning, organization and steering of public research institutes. Finally, the paper outlines some strategic objectives and orientations for the reform of public research institutes as part of the broader agenda of the Korean innovation strategy.

Trajectory Optimization and Optimal Explicit Guidance Algorithm Design for a Satellite Launch Vehicle (위성발사체의 궤적최적화와 최적 유도 알고리듬 설계)

  • Roh, Woong-Rae;Kim, Yodan;Song, Taek-Lyul
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.2
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    • pp.173-182
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    • 2001
  • Ascent trajectory optimization and optimal explicit guidance problems for a satellite launch vehicle in a 2-dimensional pitch plane are studied. The trajectory optimization problem with boundary conditions is formulated as a nonlinear programming problem by parameterizing the pitch attitude control variable, and is solved by using the SQP algorithm. The flight constraints such as gravity-turn are imposed. An optimal explicit guidance algorithm in the exoatmospheric phase is also presented, the guidance algorithm provides steering command and time-to-go value directly using the current states of the vehicle and the desired orbit insertion conditions. To verify the optimality and accuracy of the algorithm simulations are performed.

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A Fuzzy PID Control of Nonholonomic Mobile Robot (Nonholonomic 모바일 로봇의 퍼지 PID제어)

  • Kim, Do-Won;Yang, Hai-Won;Jung, Won-Chul;Hwang, Yong-Ho;Kim, Hong-Phil
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.2756-2759
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    • 2000
  • In this paper. A PID motion controller based on the fuzzy concept is discussed for nonholonomic mobile robot. The difficulties in controlling such a Mobile robot vehicle lies in the fact that it usually has only two degrees of freedom for motion control in a tracking mode. It makes the control of speed and steering possible to decompose the error between the reference posture and the current posture. The Gyro compass is used to measure the position of robot. The proposed nonholonomic mobile robot is shown to follow the reference trajectory and compensate the dynamics. Simulation results are provided to validate the proposed controller. Experiments have been used to verify the effectiveness and robustness of the motion controller.

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Variable Shapes Single-Tracked of Belt Type Wheel Mechanism (단일 궤도를 갖는 가변형 로봇 바퀴 구조)

  • Kim, Jee-Hong;Lee, Chang-Goo
    • Journal of Institute of Control, Robotics and Systems
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    • v.15 no.2
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    • pp.198-202
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    • 2009
  • Urban Search and Rescue (USAR) involves locating, rescuing (extricating), and medically stabilizing victims trapped in confined spaces. In this paper we state the current approach to USAR, address the limitations and discuss the way for moving in rugged topography. To achieve objectives such as surveillance, reconnaissance, and rescue, it is necessary to develop a driving mechanism that can handle rugged geographical features. We propose a new type of driving mechanism for a rescue robot that has a variable shape single-track. By using a variety shapes, it can get the gain of steering and rotating and the ability to overcome stairs. In this paper, we analyzed the design parameters for making variable transform shapes and determined the specifications of the robot to enhance adaptability to stairs.

A Study for Driving Mechanism Evaluation of the Lane Keeping Assistance System (차선유지지원장치 작동 메커니즘 평가에 관한 연구)

  • Chung, Seung-Hwan;Kim, Jeong-Min;Kwon, Seong-Jin;Lee, Bong-Hyun
    • Journal of Auto-vehicle Safety Association
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    • v.5 no.1
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    • pp.69-74
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    • 2013
  • LKAS(Lane Keeping Assistance System) main function is to support the driver in keeping the vehicle within the current lane. Therefore, this system is able to reduce the driver workload with assisting the driver during driving. In this paper, we presented on study for test procedures and evaluation methods of the LKAS. The vehicle test conducted on straight road, left curve, right curve and four different types of lane under various vehicle speeds. This study proposed the LKAS system test procedures and methods that we are able to identify LKAS driving mechanism and performance.

Broadband Phase-change Metagrating Design for Efficient Active Reflection Steering

  • Kim, Sun-Je
    • Current Optics and Photonics
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    • v.5 no.2
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    • pp.134-140
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    • 2021
  • In this paper, I introduce a novel design method of a high performance nanophotonic beam deflector providing broadband operation, large active tunability, and signal efficiency, simultaneously. By combining thermo-optically tunable vanadium dioxide nano-ridges and a metallic mirror, reconfigurable local optical phase of reflected diffraction beams can be engineered in a desired manner over broad bandwidth. The active metagrating deflectors are systematically designed for tunable deflection of reflection beams according to the thermal phase-change of vanadium dioxide nano-ridges. Moreover, by multiplexing the phase-change supercells, a robust design of actively tunable beam splitter is also verified numerically. It is expected that the proposed intuitive and simple design method would contribute to development of next-generation optical interconnects and spatial light modulators with high performances. The author also envisions that this study would be fruitful for modern holographic displays and three-dimensional depth sensing technologies.

Design of a 2.5V 10-bit 300MSPS CMOS D/A Converter (2.5V 10-bit 300MSPS 고성능 CMOS D/A 변환기의 설계)

  • Kwon, Dae-Hoon;Song, Min-Kyu
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.39 no.7
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    • pp.57-65
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    • 2002
  • In this paper, a 2.5V 10-bit 300MSPS CMOS D/A Converter is described. The architecture of the D/A Converter is based on a current steering 8+2 segmented type, which reduces non-linearity error and other secondary effects. In order to achieve a high performance D/A Converter, a novel current cell with a low spurious deglitchnig circuit and a novel inverse thermomeer decoder are proposed. To verify the performance, it is integrated with $0.25{\mu}m$ CMOS 1-poly 5-metal technology. The effective chip area is $1.56mm^2$ and power consumption is about 84mW at 2.5V power supply. The simulation and experimental results show that the glitch energy is 0.9pVsec at fs=100MHz, 15pVsec at fs=300MHz in worst case, respectively. Further, both of INL and DNL are within ${\pm}$1.5LSB, and the SFDR is about 45dB when sampling, frequency, is 300MHz and output frequency is 1MHz.

A Wireless Video Streaming System for TV White Space Applications (TV 유휴대역 응용을 위한 무선 영상전송 시스템)

  • Park, Hyeongyeol;Ko, Inchang;Park, Hyungchul;Shin, Hyunchol
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.4
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    • pp.381-388
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    • 2015
  • In this paper, a wireless video streaming system is designed and implemented for TV white space applications. It consists of a RF transceiver module, a digital modem, a camera, and a LCD screen. A VGA resolution video is captured by a camera, modulated by modem, and transmitted by RF transceiver module, and finally displayed at a destination 2.6-inch LCD screen. The RF transceiver is based on direct-conversion architecture. Image leakage is improved by low pass filtering LO, which successfully covers the TVWS. Also, DC offset problem is solved by current steering techniques which control common mode level at DAC output node. The output power of the transmitter and the minimum sensitivity of the receiver is +10 dBm and -82 dBm, respectively. The channel bandwidth is tunable among 6, 7 and 8 MHz according to regulations and standards. Digital modem is realized in Kintex-7 FPGA. Data rate is 9 Mbps based on QPSK and 512ch OFDM. A VGA video is successfully streamed through the air by using the developed TV white-space RF communication module.

Evaluation of Thermoelectric Characteristics of Peltier Thermoelectric Module for Increasing Response Velocity in Shape Memory Alloy (SMA) Steering Catheter (형상기억합금(SMA) 스티어링 카테터의 반응속도 향상을 위한 펠티어 열전소자의 열전기적 특성 평가)

  • Oh, Dong-Joon;Kim, Cheol-Woong;Kim, Tae-Young;Lee, Ho-Sang;Kim, Jay-Jung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.3
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    • pp.301-307
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    • 2010
  • Actuation using a shape memory alloy (SMA) is considered to be an important technology that will play a leading role in market for next-generation medical devices because an SMA actuator can accurately imitate skillful and delicate hand movements. However, SMA actuators have not been successfully used because of problems in control design caused by the nonlinear hysteresis effect of SMA, which leads to inaccuracies in control systems. In order to overcome the effect, the authors invented a SMA actuator, which could actively and rapidly cool down and heat up, by combining a SMA catheter and a TE module using the Peltier effect. In order to evaluate the TE characteristics of our TE module system, the changes in the temperature with 1) incremental increases in a continuous electric current and 2) the appearance of a discontinuous constant or reverse current are discussed in this paper.