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[Author] Takashi SAKU(6hit)

1-6hit
  • Multimodal Bioimage Sensor

    Kazuaki SAWADA  Hirokazu NAKAZAWA  Shoko TAKENAGA  Takeshi HIZAWA  Masato FUTAGAWA  Fumihiro DASAI  Takashi SAKURAI  Koichi OKUMURA  Toshiaki HATTORI  Makoto ISHIDA  

     
    INVITED PAPER

      Vol:
    E97-A No:3
      Page(s):
    726-733

    To visualize the biochemical distribution two-dimensionally, we invented a solid-state-type ion image sensor that indicates the chemical activity of solutions and cells. The device, which consists of a CCD array covered with a functionalized membrane to detect charge accumulation, is highly sensitive to changes in the concentration and two-dimensional distribution of ions and biomaterials.

  • Compact Modeling of Expansion Effects in LDMOS

    Takahiro IIZUKA  Takashi SAKUDA  Yasunori ORITSUKI  Akihiro TANAKA  Masataka MIYAKE  Hideyuki KIKUCHIHARA  Uwe FELDMANN  Hans Jurgen MATTAUSCH  Mitiko MIURA-MATTAUSCH  

     
    PAPER-Semiconductor Materials and Devices

      Vol:
    E95-C No:11
      Page(s):
    1817-1823

    In LDMOS devices for high-voltage applications, there appears a notable fingerprint of current-voltage characteristics known as soft breakdown. Its mechanism is analyzed and modeled on LDMOS devices where a high resistive drift region exists. This analysis has revealed that the softness of breakdown, known as the expansion effect, withholding a run-away of current, is contributed by the flux of holes underneath the gate-overlap region originated by impact-ionization. The mechanism of the expansion effect is modeled and implemented into the compact model HiSIM_HV for circuit simulation. A good agreement between simulated characteristics and 2D-device simulation results is verified.

  • A Hybrid Force-Directed Self-Organizing Neural Network Approach to Automatic Printed Circuit Board Component Placement with EMC Consideration

    Teck Lin ANG  Yuji TARUI  Takashi SAKUSABE  Takehiro TAKAHASHI  Noboru SCHIBUYA  

     
    PAPER-Electromagnetic Compatibility(EMC)

      Vol:
    E85-B No:9
      Page(s):
    1797-1805

    This paper describes a hybrid force-directed self-organizing neural network approach to printed circuit board (PCB) placement with consideration of electromagnetic compatibility (EMC). In most of the conventional PCB automatic placement algorithms, the only factor considered in the objective function is minimized total net length. However, for today's high speed and high density PCB, EMC compliance cannot be met by such single objective. To tackle this problem, the presented algorithm takes EMC into consideration, besides component overlap and minimized total net length. These factors are optimized by means of an adapted self-organizing map. Comparison of simulated placement results as well as actual measurements with commercial softwares confirms the effectiveness of the proposed method.

  • A Computer-Aided Distinction Method of Borderline Grades of Oral Cancer

    Mustafa M. SAMI  Masahisa SAITO  Shogo MURAMATSU  Hisakazu KIKUCHI  Takashi SAKU  

     
    PAPER-Image

      Vol:
    E93-A No:8
      Page(s):
    1544-1552

    We have developed a new computer-aided diagnostic system for differentiating oral borderline malignancies in hematoxylin-eosin stained microscopic images. Epithelial dysplasia and carcinoma in-situ (CIS) of oral mucosa are two different borderline grades similar to each other, and it is difficult to distinguish between them. A new image processing and analysis method has been applied to a variety of histopathological features and shows the possibility for differentiating the oral cancer borderline grades automatically. The method is based on comparing the drop-shape similarity level in a particular manually selected pair of neighboring rete ridges. It was found that the considered similarity level in dysplasia was higher than those in epithelial CIS, of which pathological diagnoses were conventionally made by pathologists. The developed image processing method showed a good promise for the computer-aided pathological assessment of oral borderline malignancy differentiation in clinical practice.

  • A New Hardware/Software Partitioning Algorithm for DSP Processor Cores with Two Types of Register Files

    Nozomu TOGAWA  Takashi SAKURAI  Masao YANAGISAWA  Tatsuo OHTSUKI  

     
    LETTER-Hardware/Software Codesign

      Vol:
    E84-A No:11
      Page(s):
    2802-2807

    This letter proposes a hardware/software partitioning algorithm for digital signal processor cores with two register files. Given a compiled assembly code and a timing constraint of execution time, the proposed algorithm generates a processor core configuration with a new assembly code running on the generated processor core. The proposed algorithm considers two register files and determines the number of registers in each of register files. Moreover the algorithm considers two or more types of functional units for each arithmetic or logical operation and assigns functional units with small area to a processor core without causing performance penalty. A generated processor core will have small area compared with processor cores which have a single register file or those which consider only one type of functional units for each operation. The experimental results demonstrate the effectiveness and efficiency of the proposed algorithm.

  • A Study on Performance Degradation of Digital Electronic Equipment under Electromagnetic Disturbance

    Takehiro TAKAHASHI  Hironori OKANIWA  Takashi SAKUSABE  Noboru SCHIBUYA  

     
    PAPER-Measurement and Immunity

      Vol:
    E90-B No:6
      Page(s):
    1338-1343

    In this research, the performance degradation of the digital electronic equipment under electromagnetic (EM) disturbance was studied in order to investigate the interference of intra-equipment. To develop the evaluation method of the performance degradation, some communication indexes were measured under EM disturbance. From some experimental results, it is known that the performance degradation of the electronic equipment was estimated by the degradation of "through-put," one of the communication performance indexes. For further investigation of the interference of intra-equipment, the near EM field from a PCB of the electronic equipment and its performance degradation under EM disturbance were measured and compared. From the measured results, the relationship between near field measurement and performance degradation could be obtained in some extent. These facts enable us that the weak area under the EM disturbance application on PCB can be foreseen by measuring the near field emission from the equipment and vise versa.