IEEJ Transactions on Fundamentals and Materials
Online ISSN : 1347-5533
Print ISSN : 0385-4205
ISSN-L : 0385-4205
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Volume 122, Issue 12
Displaying 1-9 of 9 articles from this issue
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Special Issue Review
Special Issue Paper
  • Fast Genetic Algorithm for Optimization of Inverse Scattering Problem
    Zhi Qi Meng, Hisayoshi Misaka
    Article type: Others
    Subject area: Others
    2002 Volume 122 Issue 12 Pages 1005-1010
    Published: 2002
    Released on J-STAGE: March 28, 2003
    DOIhttps://doi.org/10.1541/ieejfms.122.1005
    JOURNAL FREE ACCESS
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    As a global optimization method, genetic algorithm (GA) is very convenient for use in optimizing any type of parameters, especially for inverse problems, and many remarkable results have been obtained. One of the problems of GA is how to achieve the evolution towards the global minimum efficiently. This paper examines the conventional operators of GA, and introduces new techniques of mutating and seeding the population.
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  • A Study of the Crack Depth Estimation on a Conducting Surface
    Hidenori Sekiguchi, Hiroshi Shirai, Ryoichi Sato
    Article type: Others
    Subject area: Others
    2002 Volume 122 Issue 12 Pages 1011-1016
    Published: 2002
    Released on J-STAGE: March 28, 2003
    DOIhttps://doi.org/10.1541/ieejfms.122.1011
    JOURNAL FREE ACCESS
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    An algorithm to estimate non-destructively the depth of a crack has been proposed in this paper using electromagnetic waves. From our theoretical study of the scattering by a trough on a conducting surface, it is found that periodical sharp dips in the scattering return occur as one sweeps the operation frequency, and the first dip frequency corresponds to the crack depth. Based on this observation, corelation curves between the first dip frequency and the crack depth have been made. In order to check the validity of our algorithm, test measurement has been made at microwave frequency range. Gating process in the time domain has been utilized to isolate the desired scattering return from the crack model on a finite conducting metal surface. Thus processed scattering returns exhibit a similar frequency dip as predicted theoretically. By our method, one can estimate the depth of a crack within 3 percent error.
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  • Numerical Analysis of Waveguide Band-pass Filters Using Singular Integral Equations and Construction of Simple Design Formulae
    Akira Matsushima, Yasuo Fukuda
    Article type: Others
    Subject area: Others
    2002 Volume 122 Issue 12 Pages 1017-1024
    Published: 2002
    Released on J-STAGE: March 28, 2003
    DOIhttps://doi.org/10.1541/ieejfms.122.1017
    JOURNAL FREE ACCESS
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    A powerful numerical solution is presented for band-pass filters in rectangular waveguides. The filters are composed of cascading of perfectly conducting inductive obstacles with zero thickness: asymmetrical windows, symmetrical windows, or symmetrical strips. The problem is reduced to a set of singular integral equations, which is solved by an extension of Lewin’s quasi static procedure. After the accuracy of the classical formulae for the equivalent reactance is investigated, the simple inverse formulae are constructed to yield proper window widths for desired equivalent parameters. The effectiveness of them is demonstrated by designing practical filters having maximally flat or equal-ripple characteristics.
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  • Scattered Near Field of a Hermite-Gaussian Beam Wave by a Chiral Cylinder
    Mitsuhiro Yokota, Mayumi Kai
    Article type: Others
    Subject area: Others
    2002 Volume 122 Issue 12 Pages 1025-1030
    Published: 2002
    Released on J-STAGE: March 28, 2003
    DOIhttps://doi.org/10.1541/ieejfms.122.1025
    JOURNAL FREE ACCESS
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    Scattering of a Hermite-Gaussian beam wave by a chiral cylinder is analyzed. A Hermite-Gaussian beam wave is expressed as a superposition of multipole fields at complex source points. Electromagnetic fields are expanded in terms of the cylindrical vector wave functions. The unknown expansion coefficients for the scattered field and the internal field are determined by the boundary conditions. As numerical examples, the scattered near fields of the beam incidence are calculated and the effects of chirality, the polarization and the radius of the chiral cylinder on the fields are examined.
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  • Progressive Analysis of Electromagnetic Field by Parallel FDTD Algorithm for Big Urban Area 2-D Simulations
    Glen Rodriguez, Yasumitsu Miyazaki
    Article type: Others
    Subject area: Others
    2002 Volume 122 Issue 12 Pages 1031-1037
    Published: 2002
    Released on J-STAGE: March 28, 2003
    DOIhttps://doi.org/10.1541/ieejfms.122.1031
    JOURNAL FREE ACCESS
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    This paper explores some improvements in the parallel FDTD algorithm using system of linear equations. The objectives are to be able to simulate realistic size models of urban wireless communications using FDTD. The obstacles are the need of large memory and processing time. The previous research has dealt with decreasing the use of memory. From now, the research deals with the improvement of the speed of the algorithm. This is done by using the properties of the impulse response in the system of equations and using it to store pre calculated results that are the most common calculations in FDTD equations.
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  • Design Study of Three-Dimensional Microwave Simulator Engine
    Hideki Kawaguchi, Koki Hirose, Makoto Horita, Shunsuke Matsuoka, Kenji ...
    Article type: Others
    Subject area: Others
    2002 Volume 122 Issue 12 Pages 1038-1044
    Published: 2002
    Released on J-STAGE: March 28, 2003
    DOIhttps://doi.org/10.1541/ieejfms.122.1038
    JOURNAL FREE ACCESS
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    According to big demands for high performance computing of simulation of microwave phenomena in industries, development of specialized purpose digital circuit hardware is proposed instead of use of very large scale supercomputer. That is, by specializing simulation target, very high performance simulator is realized with much smaller hardware size than supercomputers. Authors already presented a design study of simulator engine for two dimensional microwave. However, three-dimensional em fields are much practical in microwave industory. From this viewpoint, design study of simulator engine for three dimensional microwave is discussed in this paper.
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Paper
  • The Production of the Micro-lens by means of the YAG Laser Ion Exchange Method
    Akira Mori, Masamitsu Yoshida, Takashi Tatuguchi, Tatuya Kosuge, Nobuy ...
    Article type: Others
    Subject area: Others
    2002 Volume 122 Issue 12 Pages 1045-1051
    Published: 2002
    Released on J-STAGE: March 28, 2003
    DOIhttps://doi.org/10.1541/ieejfms.122.1045
    JOURNAL FREE ACCESS
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    The ion exchange method is widely used to produce micro-lenses. Types of the ion exchange method include the sedimentation by thermo ion exchange technique, the electrolytic importation method, and the CVD method. However, all of these methods require a process involving a photo mask, and require a long production time. Thus, the laser ion exchange method was developed in which the minimum region is irradiated using a Nd-YAG laser beam. When the laser beam irradiates the minimum region. The locally irradiated part is heated to a high temperature. This method is simultaneously optical damage and ion exchange in the irradiated area. It can prepare a minute lens of approximately about 200 μm. The difference of refractive index made 2.8×10-3 maximum. This paper describes the results of research regarding the production of planar micro-lenses by means of the laser ion exchange method a using Nd-YAG laser. The evaluation of the produced lens is also described.
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  • Weatherability and Tracking Resistance Evaluation and Degradation Analysis of Hydrophobic Epoxy Polymer
    Shuuichi Urabe, Tetsu Fujisawa, Sachio Yoshihara, Takashi Shirakashi, ...
    Article type: Others
    Subject area: Others
    2002 Volume 122 Issue 12 Pages 1052-1058
    Published: 2002
    Released on J-STAGE: March 28, 2003
    DOIhttps://doi.org/10.1541/ieejfms.122.1052
    JOURNAL FREE ACCESS
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    The hydrophobic epoxy resin system for outdoor insulation was examined by various endurance tests, that is, high energy Xenon weathering test, ozone aging test, and acid rain test. After them, following properties were evaluated, e.g. surface micro-formation, surface roughness, contact angle, and tracking and erosion resistance. These surface properties of the hydrophobic and the conventional epoxy systems were not changed after the ozone aging test and the acid rain test. However after the Xenon weathering test, these properties were changed. The contact angle of conventional cycloaliphatic epoxy system was declined, but the contact angle of hydrophobic epoxy system was increased with progressing the test. From the IEC tracking test, is was confirmed that tracking and erosion resistance of the hydrophobic epoxy system was better than the conventional cycloaliphatic epoxy system. As the result of the degradation analysis, it was clarified that even though the base material is the same, hydrophobic epoxy system has much better weatherability.
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