A5064535855- Mechanical and Optical Resonators
- Multilevel Inverters and Converters
- Analog and Mixed-Signal Circuit Design
- Advanced DC-DC Converters
- Silicon Carbide Semiconductor Technologies
- Low-power high-performance VLSI design
- Advanced Fiber Laser Technologies
- Structural Analysis and Optimization
- Advancements in Semiconductor Devices and Circuit Design
- Concrete Corrosion and Durability
- Ship Hydrodynamics and Maneuverability
- Geophysics and Sensor Technology
- Vibration and Dynamic Analysis
- Advancements in PLL and VCO Technologies
- CCD and CMOS Imaging Sensors
- Tunneling and Rock Mechanics
- Advanced Fiber Optic Sensors
- Electromagnetic Compatibility and Noise Suppression
- Cold Atom Physics and Bose-Einstein Condensates
- Sensorless Control of Electric Motors
- Structural Health Monitoring Techniques
- Fluid Dynamics Simulations and Interactions
- Advanced Thermodynamics and Statistical Mechanics
- Electric Motor Design and Analysis
- Infrastructure Maintenance and Monitoring
Tokyo Institute of Technology
2002-2024
Toshiba (Japan)
1998-2008
Fujitsu (Japan)
2003
Toshiba (South Korea)
1998
This paper describes a variable supply-voltage (VS) scheme. From an external supply, the VS scheme automatically generates minimum internal supply voltages by feedback control of buck converter, speed detector, and timing controller so that they meet demand on its operation frequency. A 32-b RISC core processor is developed in 0.4-/spl mu/m CMOS technology which optimally controls supple with threshold through substrate bias control. Performance MIPS/W improved factor more than two compared...
A 60-mW MPEG4 video codec has been developed for mobile multimedia applications. This supports both the H.263 ITU-T recommendation and simple profile of committee draft version 1 released in November 1997. It is composed a 16-bit reduced instruction set computer processor several dedicated hardware engines so as to satisfy power efficiency programmability. performs 10 frames/s encoding decoding with quarter-common intermediate format at 30 MHz. Several innovative low-power techniques were...
We propose and experimentally demonstrate the generation of enhanced optical springs using Kerr effect. A nonlinear crystal is inserted into a Fabry-Perot cavity with movable mirror, chain second-order effects in phase-mismatched condition induces The spring constant by factor 1.6±0.1 over linear theory. To our knowledge, this first realization optomechanical coupling enhancement effect, which has been theoretically investigated to overcome performance limitations systems. tunable...
In this paper, we present a comparison between 2.5kV silicon carbide (SiC-) PiN diode and commercial 3.3kV (Si-) with injection enhancement gate transistor (Si-IEGT) in the inductively loaded chopper circuit. The experimental switching characteristics of SiC-PiN are presented under 1200-V DC bias voltage 40-A cutoff current compared to commercially available Si-PiN diode. Experimental results show that reverse recovery time Si-IEGT turn-on loss significantly reduced combination Si-IEGT....
This article summarizes our study to develop an intracavity parametric signal amplification system for improving the sensitivity of a gravitational-wave detector at high frequencies aim observation postmerger remnant binary neutron star collision. The configuration is based on dual recycling interferometer and optical amplifier crystal inserted into cavity. cavity detuned spring generated differential motion two end mirrors. converts energy pump beam frequency can be enhanced few kilohertz....
This paper presents a new hardware embedded current control PWM named "iPWM", which was developed based on hysteresis PWM. iPWM generates signals to the inverter using deviation vector derived from feedback and reference. It is expected that can improve performance of inverter. explains outline experimental results permanent magnet synchronous motor (PMSM) drive.
A new control method for parallel connected current type PWM rectifiers high power applications which can achieve state feedback to improve the AC input waveform is proposed. The main circuit configuration suppress inter-bridge currents, methods of and DC output a generating pattern are shown. effectiveness proposed strategy confirmed by some experimental investigations.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>
We present a number of approaches, currently in experimental development our research groups, toward the general problem macroscopic quantum mechanics, i.e., manifestations noise and fluctations with (engineered microfabricated by man) mechanical systems. Discussed experiments include pendulum, torsion ng-scale phononic-crystal silicon nitride membrane, μ g-scale quartz resonator, mg-scale mirrors for optical levitation. also discuss relevant applications to thermometry optomechanical...
A new control strategy for a three phase voltage type PWM rectifier is described. This introduces state feedback of an LC filter inserted on the AC side power converter and has advantage fast response to changes in input current load while operating with unity factor sinusoidal supply currents produce regulated DC voltage. Simulation results from study proposed show that transient performance improved follows closely reference even very low resistance inductors. Experimental are also...
We propose and experimentally demonstrate the generation of enhanced optical springs using Kerr effect. A nonlinear crystal is inserted into a Fabry-Perot cavity with movable mirror, chain second-order effects in phase-mismatched condition induces The spring constant by factor $1.6\pm0.1$ over linear theory. To our knowledge, this first realization optomechanical coupling enhancement effect, which has been theoretically investigated to overcome performance limitations systems. tunable...
This paper proposes a tail current source dividing technique for increasing precision of track-and-hold circuit without reducing the sample speed. The proposed is based on division into two sources during hold period to reduce signal errors caused by parasitic capacitance coupling between input and output terminals. With technique, SFDR 62 dB 25 MHz, 1 V/sub p-p/ at 200 MS/s achieved with 0.35 /spl mu/m CMOS parameters HSPICE simulation.