Curriculum Vitaes

Naoto Usami

  (宇佐美 尚人)

Profile Information

Affiliation
Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency

J-GLOBAL ID
201801018289126150
researchmap Member ID
B000325823

Awards

 1

Major Papers

 19
  • Naoto Usami, Etsuko Ota, Akio Higo, Takeshi Momose, Yoshio Mita
    IEEE Transactions on Semiconductor Manufacturing, 34(3) 270-277, 2021  Peer-reviewedLead authorCorresponding author
  • Naoto Usami, Arnab Muhuri, Avik Bhattacharya, Akira Hirose
    IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, 13(12) 2029-2033, Dec, 2016  Peer-reviewedLead author
    Polarimetric synthetic aperture radar is expected to distinguish wet snow from bare ground. However, since both of them show surface scattering, which is sensitive to incidence angle, it often fails in the distinction in mountainous areas. In this letter, we propose an adaptive distinction method using quaternion neural networks. In the ALOS-2 data, we find a monotonic and nonlinear dependence of the degree of polarization on the incidence angle. Then, we feed multiple-incidence-angle teacher information in the learning process. The distinction results of the proposal present higher accuracy than those of the conventional Wishart distinction and a quaternion neural network without the incidence angle information.

Presentations

 53
  • Kazutaka Kinugawa, Fang Shang, Naoto Usami, Akira Hirose
    2016 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM (IGARSS), 2016, IEEE
    Previously, we have proposed a successful land classification method using a quaternion neural network (QNN) to process parameters based on Stokes vector representation. In this method. the activation function used in the QNN is anisotropic and is applied to input quaternions of which elements are separately and independently processed. In this paper, considering the isotropy of Poincare-sphere space, we propose a new isotropic activation function. Experimental results show that the QNN with the proposed activation function achieves more accurate land classification.
  • 宇佐美尚人, 廣瀬明
    電気学会電磁界理論研究会資料, May 24, 2014
  • Naoto Usami, Akira Hirose
    2014 ASIA-PACIFIC MICROWAVE CONFERENCE (APMC), 2014, IEEE
    Reconfigurable circular-polarized antennas are expected to improve ground penetrating radars (GPRs) utilizing high-density arrayed and complexly switched antennas. This report presents a wideband reconfigurable circular-polarized single-feed antenna. It comprises a waveguide and a T-shaped probe. We switch its polarization type by changing the bias state of two PIN diodes on the "f-probe. Simulation results show that the 3-dB axial ratio bandwidth of the proposed antenna is 29% at 7.5GHz center frequency. The results also show that the main-polarized beam width is 70 degree in the 3-dB axial ratio bandwidth.

Teaching Experience

 1

Research Projects

 3

Other

 1