A5078019076- Planetary Science and Exploration
- Quantum Dots Synthesis And Properties
- Advanced Materials and Mechanics
- Copper Interconnects and Reliability
- Semiconductor materials and devices
- Advanced Sensor and Energy Harvesting Materials
- Integrated Circuits and Semiconductor Failure Analysis
- Metal and Thin Film Mechanics
- Modular Robots and Swarm Intelligence
- Nanowire Synthesis and Applications
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Chalcogenide Semiconductor Thin Films
- Energy Harvesting in Wireless Networks
- Rocket and propulsion systems research
- Spacecraft Design and Technology
- Adhesion, Friction, and Surface Interactions
- Diamond and Carbon-based Materials Research
- Spacecraft and Cryogenic Technologies
- Micro and Nano Robotics
- Advanced Semiconductor Detectors and Materials
- Radio Astronomy Observations and Technology
- Antenna Design and Analysis
- Dielectric materials and actuators
- Cryospheric studies and observations
- Microwave Engineering and Waveguides
Japan Aerospace Exploration Agency
2021-2025
Institute of Space and Astronautical Science
2021-2025
The University of Tokyo
2014-2023
Tokyo University of Information Sciences
2016-2021
Quaternion neural networks (QNNs) achieve high accuracy in polarimetric synthetic aperture radar classification for various observation data by working Poincare-sphere-parameter space. The performance arises from the good generalization characteristics realized a QNN as 3-D rotation well amplification/attenuation, which is consistency with isotropy polarization-state representation it deals with. However, there are still two anisotropic factors so far lead to capability degraded its ideal...
Polarimetric synthetic aperture radar is expected to distinguish wet snow from bare ground. However, since both of them show surface scattering, which sensitive incidence angle, it often fails in the distinction mountainous areas. In this letter, we propose an adaptive method using quaternion neural networks. ALOS-2 data, find a monotonic and nonlinear dependence degree polarization on angle. Then, feed multiple-incidence-angle teacher information learning process. The results proposal...
In this paper, we propose an effective wet snow mapping method with focus on the incident angle of microwave. Surface scattering is dominant for both and bare ground. However, it expected that characteristic different from ground one according to variation dielectric constant. At same time, surface characteristics, especially depolarization, also depend angle. First, evaluate numerically degree polarization horizontal wave as example a simplified integral equation model (IEM). We examine...
Previously, we have proposed a successful land classification method using quaternion neural network (QNN) to process parameters based on Stokes vector representation. In this method, the activation function used in QNN is anisotropic and applied input quaternions of which elements are separately independently processed. paper, considering isotropy Poincare-sphere space, propose new isotropic function. Experimental results show that with achieves more accurate classification.
Aim to Japan's participation in the Artemis program 2030s mind, we pursue feasibility studies of lunar telescope, including astronomical observations. Focusing on meter-wavelength observations (observing frequency lower than 50MHz), which cannot be observed harsh environments ground from Earth, ionosphere and radio interference, have reported conceptual design based results our Japan. The main scientific objectives studied so far are broadly covering following three areas: astronomy...
Widespread research is being conducted on computational materials. The challenge for the realization of materials how to weave computers into everyday objects consisting various shapes and form factors. One idea achieve this vision build physical particles that can cooperatively communicate among others and, thereby, change whole shape like clay. Wireless communication power transfer are keys making such computing happen. Thus, we introduce an approach embody these using multiple tiny IC...
This paper presents a versatile chip-level wireless driving method for microelectromechanical system (MEMS) actuators. A MEMS actuator is integrated as an electrical component of coupled LCR resonant circuit, and it rectifies the energy sent through ultrahigh-frequency (UHF) radio frequency (RF) wave. Two types actuators were remotely driven using proposed method: thermal (bimorph) used R capacitive (comb-drive) C receiver circuit. We demonstrated remote actuation 13 Ω transferring 7.05 mW...
Imaging devices for near-infrared wavelengths on silicon large scale integration (LSI) are very attractive secure applications. We here demonstrate an LSI-compatible hybrid IR detector by integrating PbS quantum dots the surface of silicon.
We present a self-deformable flexible tweezer capable of simultaneous mechanical handling and electrical measurements. The has soft cantilever with the dimensions 2 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times8$ </tex-math></inline-formula> notation="LaTeX">$\times $ 75- notation="LaTeX">$100~\mu \text{m}$ , undergoes self-deformation. device is shown to be successfully detecting signals by...
Near-infrared detectors by silicon based devices with large scale integration are very attractive for secure applications about image sensors. Beyond the bandgap, we focus on PbS colloidal quantum dots (CQDs) and integration. In this paper, investigated fabrication processes of CQDs hybrid IR detector. Temperature dependent photoluminescence thin films measured found bandgap do not change various temperature. Optical response a spectrometer were observed in 1550 nm range.
We propose a micro-scale electrostatic attach-detach actuator device as an enabling component of micro selfre-configurable modular robotic system (SMR), or programmable matter. The is composed number identical tiny agents that can adhere each other to form arbitral shapes. Au electrodes sandwiched by Parylene-C flexible substrate films. film made planar, and the SMR agent realized wrapping around shell unit robot, precise 3-D printing. have measured adhesive strength be 99.3 μN at 50 V,...
Characterizing junction is essential in new devices research. We are investigating a hybrid infrared-sensitive opto-electronic device on silicon-based large scale integrated circuits, among others, PbS colloidal quantum dots/ZnO/Si IR detector. To assess such materials we propose coaxial circular test structure. The structure composed of common-central inner (circular) and outer (doughnut) electrodes. In addition to traditional Circular TLM (CTLM) structure, which was used for ohmic contact,...
Investigating heterointerfaces with test structures is crucial for fabricating electronic and photonic devices.Recently, we proposed developed a PbS colloidal quantum dot/ZnO/Si hybrid infrared detector infrared-sensitive optoelectronic devices on silicon-based large-scale integrated circuits.The conventional circular transfer length method (CTLM) commonly used evaluating Ohmic contact.To apply the CTLM to heterointerface junction, propose coaxial (CCTLM) that includes electrode in middle...
We evaluated supercritical fluid deposition (SCFD) copper thin films compatibility as a seed layer of electroplating processes. SCFD is an attractive technology for conformal metal coating on walls high-aspect-ratio micro/nano structures (HARMS/HARNS), including trenches and holes. Therefore, it has great potential layer. To utilize layers, we assessed the electrical topological continuity films. The measurements efficiently identified suitability various process, which could not be achieved...
This paper reports an area-selective supercritical fluid deposition (SCFD) of Cu with CO2 and H2 reductant. We demonstrated SCFD on TiN pre-patterned over a SiO2 underlayer Si substrate. Atomic force microscopy Auger electron spectroscopy were employed to characterize the fabricated samples. Several experiments revealed dependence surface material as well proximity effect, which made selective possible metal surfaces insulating underlayers.
supercritical fluid deposition (SCFD)