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  2. 宇佐美 尚人

宇佐美 尚人

ウサミ ナオト  (Naoto Usami)

基本情報

所属
国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 宇宙機応用工学研究系 助教
J-GLOBAL ID
201801018289126150
researchmap会員ID
B000325823

研究キーワード

 4

研究分野

 3

経歴

 5

学歴

 3

受賞

 1

主要な論文

 19
  • Naoto Usami, Etsuko Ota, Akio Higo, Takeshi Momose, Yoshio Mita
    IEEE Transactions on Semiconductor Manufacturing 34(3) 270-277 2021年  査読有り筆頭著者責任著者
  • Naoto Usami, Arnab Muhuri, Avik Bhattacharya, Akira Hirose
    IEEE GEOSCIENCE AND REMOTE SENSING LETTERS 13(12) 2029-2033 2016年12月  査読有り筆頭著者
    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.
もっとみる

講演・口頭発表等

 53
  • Kazutaka Kinugawa, Fang Shang, Naoto Usami, Akira Hirose
    2016 IEEE INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM (IGARSS) 2016年 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 2014年5月24日
  • Naoto Usami, Akira Hirose
    2014 ASIA-PACIFIC MICROWAVE CONFERENCE (APMC) 2014年 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.

担当経験のある科目(授業)

 1

所属学協会

 3

共同研究・競争的資金等の研究課題

 3

その他

 1
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