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[Author] Hiroyuki MIYATA(3hit)

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  • Satellite Image Processing System Utilizing an Extended Cellular Array Processor

    Masataka AJIRO  Hiroyuki MIYATA  Takashi KAN  Masakazu SOGA  Makoto ONO  

     
    PAPER

      Vol:
    E76-D No:10
      Page(s):
    1199-1207

    Since its successful launch in February of 1992, the Japan Earth Resources Satellite-1 (JERS-1) has been sending back high resolution images of the earth for various studies, including the investigation of earth resources, the preservation of environments and the observation of coastal lines. Currently, received images are processed using the Earth Resources Satellite Data Information System (ERSDIS). The ERSDIS is a high speed image processing system utilizing an extended cellular array processor as its main processing module. The extended cellular array processor (CAP), consisting of 4096 processing elements configured into a two-dimensional array, is designed to have many parallel processing optimizing capabilities targetting large-scale image processing at a high speed. This paper desctribes a typical image processing flow, the structure of the ERSDIS, and the details of the CAP design.

  • Dispersion on Intervals

    Tetsuya ARAKI  Hiroyuki MIYATA  Shin-ichi NAKANO  

     
    PAPER-Algorithms and Data Structures

      Pubricized:
    2022/03/08
      Vol:
    E105-A No:9
      Page(s):
    1181-1186

    Given a set of n disjoint intervals on a line and an integer k, we want to find k points in the intervals so that the minimum pairwise distance of the k points is maximized. Intuitively, given a set of n disjoint time intervals on a timeline, each of which is a time span we are allowed to check something, and an integer k, which is the number of times we will check something, we plan k checking times so that the checks occur at equal time intervals as much as possible, that is, we want to maximize the minimum time interval between the k checking times. We call the problem the k-dispersion problem on intervals. If we need to choose exactly one point in each interval, so k=n, and the disjoint intervals are given in the sorted order on the line, then two O(n) time algorithms to solve the problem are known. In this paper we give the first O(n) time algorithm to solve the problem for any constant k. Our algorithm works even if the disjoint intervals are given in any (not sorted) order. If the disjoint intervals are given in the sorted order on the line, then, by slightly modifying the algorithm, one can solve the problem in O(log n) time. This is the first sublinear time algorithm to solve the problem. Also we show some results on the k-dispersion problem on disks, including an FPTAS.

  • FPGA Implementation of Various Elliptic Curve Pairings over Odd Characteristic Field with Non Supersingular Curves

    Yasuyuki NOGAMI  Hiroto KAGOTANI  Kengo IOKIBE  Hiroyuki MIYATAKE  Takashi NARITA  

     
    PAPER-Cryptography and cryptographic protocols

      Pubricized:
    2016/01/13
      Vol:
    E99-D No:4
      Page(s):
    805-815

    Pairing-based cryptography has realized a lot of innovative cryptographic applications such as attribute-based cryptography and semi homomorphic encryption. Pairing is a bilinear map constructed on a torsion group structure that is defined on a special class of elliptic curves, namely pairing-friendly curve. Pairing-friendly curves are roughly classified into supersingular and non supersingular curves. In these years, non supersingular pairing-friendly curves have been focused on from a security reason. Although non supersingular pairing-friendly curves have an ability to bridge various security levels with various parameter settings, most of software and hardware implementations tightly restrict them to achieve calculation efficiencies and avoid implementation difficulties. This paper shows an FPGA implementation that supports various parameter settings of pairings on non supersingular pairing-friendly curves for which Montgomery reduction, cyclic vector multiplication algorithm, projective coordinates, and Tate pairing have been combinatorially applied. Then, some experimental results with resource usages are shown.