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[Keyword] MEC(226hit)

221-226hit(226hit)

  • Natural Laws and Information Processing

    Yasuji SAWADA  

     
    INVITED PAPER

      Vol:
    E76-C No:7
      Page(s):
    1064-1069

    We discuss possible new principles of information processing by utilizing microscopic, semi-microscopic and macroscopic phenomena occuring in nature. We first discuss quantum mechanical universal information processing in microscopic world governed by quantum mechanics, and then we discuss superconducting phenomena in a mesoscopic system, especially an information processing system using flux quantum. Finally, we discuss macroscopic self-organizing phenomena in biology and suggest possibility of self-organizing devices.

  • CNV Based Intermedia Synchronization Mechanism under High Speed Communication Environment

    Chan-Hyun YOUN  Yoshiaki NEMOTO  Shoichi NOGUCHI  

     
    PAPER-Communication Networks and Service

      Vol:
    E76-B No:6
      Page(s):
    634-645

    In this paper, we discuss to the intermedia synchronization problems for high speed multimedia communication. Especially, we described how software synchronization can be operated, and estimated the skew bound in CNV when considering the network delay. And we applied CNV to the intermedia synchronization and a hybrid model (HSM) is proposed. Furthermore, we used the statistical approach to evaluate the performance of the synchronization mechanisms. The results of performance evaluation show that HSM has good performance in the probability of estimation error.

  • Unsupervised Learning of 3D objects Conserving Global Topological Order

    Jinhui CHAO  Kenji MINOWA  Shigeo TSUJII  

     
    PAPER-Neural Nets--Theory and Applications--

      Vol:
    E76-A No:5
      Page(s):
    749-753

    The self-organization rule of planar neural networks has been proposed for learning of 2D distributions. However, it cannot be applied to 3D objects. In this paper, we propose a new model for global representation of the 3D objects. Based on this model, global topology reserving self-organization is achieved using parallel local competitive learning rule such as Kohonen's maps. The proposed model is able to represent the objects distributively and easily accommodate local features.

  • Mechanical Optical Switch for Single Mode Fiber

    Masanobu SHIMIZU  Koji YOSHIDA  Toshihiko OHTA  

     
    PAPER

      Vol:
    E76-B No:4
      Page(s):
    370-374

    The 22 mechanical optical switch for single mode fiber (SMF) is reported. By using the precision grinding and molding techniques all-plastic multiple-fiber connector, 22 pin-referenced indirect slide switch is developed. The characteristics and the reliability test's results of this optical switch are also reported. Evaluations confirm that the switch has low insertion loss, high-speed switching, stable switching operations and reliability in practical applications.

  • Equivalent Edge Currents by the Modified Edge Representation: Physical Optics Components

    Tsutomu MURASAKI  Makoto ANDO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E75-C No:5
      Page(s):
    617-626

    The method of equivalent edge currents (MEC) has some ambiguity about definition of edge currents at general edge points except for diffraction points. The modified edge representation is introduced to overcome this ambiguity. The modified edge is the fictitious one which is defined so as to satisfy the diffraction law for given directions of incidence and observation. The equivalent edge currents for physical optics (PO) components at general edge points are obtained by utilizing these fictitious edges and the classical Keller's diffraction coefficients. High potentials of these currents are numerically demonstrated for diffraction from a disk, a square plate and a parabolic reflector.

  • Experimentally Verified Majority and Minority Mobilities in Heavily Doped GaAs for Device Simulations

    Herbert S. BENNETT  Jeremiah R. LOWNEY  Masaaki TOMIZAWA  Tadao ISHIBASHI  

     
    PAPER

      Vol:
    E75-C No:2
      Page(s):
    161-171

    Low-field mobilities and velocity versus electric field relations are among the key input parameters for drift-diffusion simulations of field-effect and bipolar transistors. For example, most device simulations that treat scattering from ionized impurities contain mobilities or velocity versus field relations based on the Born approximation (BA). The BA is insensitive to the sign of the charged impurity and is especially poor for ionized impurity scattering because of the relatively strong scattering of long-wavelength carriers, which have low energies, and therefore violate the validity condition for the BA. Such carriers occur at high symmetry points in the Brillouin zone and are critical for device behavior. There has been a tendency in the past to assume that majority and minority mobilities are equal. This assumption can lead to incorrect interpretations of device data and thereby misleading design strategies based on such simulations. We have calculated the majority electron and minority hole mobilities in GaAs at 300 K for donor densities between 51016 and 11019 cm-3 and the majority hole and minority electron mobilities for acceptor densities between 51016 and 11020 cm-3. We have included all the important scattering mechanisms for GaAs: acoustic phonon, polar optic phonon, nonpolar optic phonon (holes only), piezoelectric, ionized impurity, carrier-carrier, and plasmon scattering. The ionized impurity and carrier-carrier scattering processes have been calculated with a quantum mechanical phase-shift analysis to obtain more accurate matrix elements for these two scattering mechanisms. We compare the total scattering rate for majority electrons due to ionized impurities based on exact phase shifts and on the BA used by Brooks-Herring. We also present additional data that show the differences between the exact phase-shift analyses and the BA for majority electron scattering rates as functions of carrier energy and scattering angle. These results show that the calculated low-field mobilities are in good agreement with experiment, but they predict that at high dopant densities minority mobilities should increase with increasing dopant density for a short range of densities. This effect occurs because of the reduction of plasmon scattering and the removal of carriers from carrier-carrier scattering because of the Pauli exclusion principle. Some recent experiments support this finding. These results are important for device modeling because of the need to have reliable values for the minority mobilities and velocity-field relations.

221-226hit(226hit)