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[Author] Akira NAKAYAMA(4hit)

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  • An Improved Reflection Wave Method for Measurement of Complex Permittivity at 100 MHz-1GHz

    Akira NAKAYAMA  Kazuya SHIMIZU  

     
    PAPER-Microwave and Millimeter Wave Technology

      Vol:
    E77-C No:4
      Page(s):
    633-638

    An improved reflection wave method was described for measurement of complex permittivity of low-loss materials over 100MHz-1GHz range. The residual impedance Zr and stray admittance Ys surrounding the test sample, which terminated the transmission line, were evaluated using sapphire as a reference material. The correction by the obtained Zr and Ys gave accurate values of complex permittivities of alumina and mullite ceramics as 100MHz-1GHz.

  • Facial Caricaturing Based on Visual Illusion--A Mechanism to Evaluate Caricature in PICASSO System--

    Kazuhito MURAKAMI  Hiroyasu KOSHIMIZU  Akira NAKAYAMA  Teruo FUKUMURA  

     
    PAPER

      Vol:
    E76-D No:4
      Page(s):
    470-478

    In the PICASSO, a system for the facial caricature generation, as the basic mechanisms to extract the individuality features of faces and to deform the features have been already introduced, it is expected to realize an autonomous mechanism to evaluate facial caricatures. The evaluation should be based on the framework of human visual cognition. In the PICASSO, some visual illusions such as the Wundt-Fick illusion and the Ponzo illusion for example, are applied to evaluate the shapes of the facial parts such as eyebrows, nose, mouth and face contour, in the deformation process. In many cases, as well-deformed caricatures are evaluated to be successful, it is confirmed that the utilization of the visual illusion is effective to evaluate the results of caricatures. In this paper, some experimental results are presented together with the definition of the evaluation measures and the further subjects.

  • Complex Permittivity Measurement at Pseudo Microwave Frequency Using a Dielectric-Plate-Loaded Cavity Resonator

    Akira NAKAYAMA  Atsuomi FUKUURA  Michiaki NISHIMURA  

     
    PAPER-Microwave and Millimeter Wave Technology

      Vol:
    E80-C No:8
      Page(s):
    1117-1125

    This paper describes a nondestructive measurement method for complex permittivity of dielectric plates at 2 GHz, using a cylindrical cavity resonator. The resonator is divided into two parts at the center. Two dielectric plates are symmetrically loaded around the center of the cavity. These plates have high permittivity of 45. A dielectric plate specimen is clamped with these halves. The values of relative permittivity ε and loss tangent tanδ of the specimen are obtained from the resonant frequency and unloaded Q-value of TE011 mode. Measured results of various materials are compared with those values obtained at 3 and 10 GHz by other cavity resonator method. An edge effect is taken into account by a reference method, using measurement data of a sapphire plate. The errors of the present method are smaller than 1% and 2-310-5 for ε and tanδ, respectively.

  • A Measurement Method of Complex Permittivity at Pseudo Microwave Frequencies Using a Cavity Resonator Filled with Dielectric Material

    Akira NAKAYAMA  

     
    PAPER

      Vol:
    E77-C No:6
      Page(s):
    894-899

    This paper describes a nondestructive measurement method for complex permittivity of dielectric material at pseudo microwave frequencies. The resonator used in this study has a cylindrical cavity filled with a sapphire material of a well known complex permittivity. The resonator is divided into two parts at the center. A dielectric substrate specimen is clamped with these halves. Relative permittivity εand loss tangent tan δ of the specimen are obtained at 3 GHz using the TE011 resonance mode. The accuracy of the present method is evaluated through the comparison of the measured values by the new method with those at around 10 GHz by the conventional empty cavity resonator method. The errors of measurements are smaller than 1% and 1105 for εand tan δ, respectively.