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[Author] Tetsuya HIROSE(25hit)

21-25hit(25hit)

  • Compressed Sensing EEG Measurement Technique with Normally Distributed Sampling Series

    Yuki OKABE  Daisuke KANEMOTO  Osamu MAIDA  Tetsuya HIROSE  

     
    LETTER-Measurement Technology

      Pubricized:
    2022/04/22
      Vol:
    E105-A No:10
      Page(s):
    1429-1433

    We propose a sampling method that incorporates a normally distributed sampling series for EEG measurements using compressed sensing. We confirmed that the ADC sampling count and amount of wirelessly transmitted data can be reduced by 11% while maintaining a reconstruction accuracy similar to that of the conventional method.

  • Improvement of Luminance Isotropy for Convolutional Neural Networks-Based Image Super-Resolution

    Kazuya URAZOE  Nobutaka KUROKI  Yu KATO  Shinya OHTANI  Tetsuya HIROSE  Masahiro NUMA  

     
    LETTER-Image

      Vol:
    E103-A No:7
      Page(s):
    955-958

    Convolutional neural network (CNN)-based image super-resolutions are widely used as a high-quality image-enhancement technique. However, in general, they show little to no luminance isotropy. Thus, we propose two methods, “Luminance Inversion Training (LIT)” and “Luminance Inversion Averaging (LIA),” to improve the luminance isotropy of CNN-based image super-resolutions. Experimental results of 2× image magnification show that the average peak signal-to-noise ratio (PSNR) using Luminance Inversion Averaging is about 0.15-0.20dB higher than that for the conventional super-resolution.

  • A CMOS Watchdog Sensor for Certifying the Quality of Various Perishables with a Wider Activation Energy

    Ken UENO  Tetsuya HIROSE  Tetsuya ASAI  Yoshihito AMEMIYA  

     
    PAPER

      Vol:
    E89-A No:4
      Page(s):
    902-907

    We developed a CMOS watchdog sensor that simulates the changes in quality of perishables such as farm and marine products. The sensor can imitate a chemical reaction that causes the changes in the quality of perishables, with a wide range of activation energy from 0.1 eV to 0.7 eV. Attached to perishable goods, the sensor simulates the deterioration of the goods caused by surrounding temperatures. By reading the output of the sensor, consumers can determine whether the goods are fresh or not. This sensor consists of subthreshold CMOS circuits with a low-power consumption of 5 µW or less.

  • Multi-Category Image Super-Resolution with Convolutional Neural Network and Multi-Task Learning

    Kazuya URAZOE  Nobutaka KUROKI  Yu KATO  Shinya OHTANI  Tetsuya HIROSE  Masahiro NUMA  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2020/10/02
      Vol:
    E104-D No:1
      Page(s):
    183-193

    This paper presents an image super-resolution technique using a convolutional neural network (CNN) and multi-task learning for multiple image categories. The image categories include natural, manga, and text images. Their features differ from each other. However, several CNNs for super-resolution are trained with a single category. If the input image category is different from that of the training images, the performance of super-resolution is degraded. There are two possible solutions to manage multi-categories with conventional CNNs. The first involves the preparation of the CNNs for every category. This solution, however, requires a category classifier to select an appropriate CNN. The second is to learn all categories with a single CNN. In this solution, the CNN cannot optimize its internal behavior for each category. Therefore, this paper presents a super-resolution CNN architecture for multiple image categories. The proposed CNN has two parallel outputs for a high-resolution image and a category label. The main CNN for the high-resolution image is a normal three convolutional layer-architecture, and the sub neural network for the category label is branched out from its middle layer and consists of two fully-connected layers. This architecture can simultaneously learn the high-resolution image and its category using multi-task learning. The category information is used for optimizing the super-resolution. In an applied setting, the proposed CNN can automatically estimate the input image category and change the internal behavior. Experimental results of 2× image magnification have shown that the average peak signal-to-noise ratio for the proposed method is approximately 0.22 dB higher than that for the conventional super-resolution with no difference in processing time and parameters. We have ensured that the proposed method is useful when the input image category is varying.

  • A Sub-1-µs Start-Up Time, Fully-Integrated 32-MHz Relaxation Oscillator for Low-Power Intermittent Systems

    Hiroki ASANO  Tetsuya HIROSE  Taro MIYOSHI  Keishi TSUBAKI  Toshihiro OZAKI  Nobutaka KUROKI  Masahiro NUMA  

     
    PAPER-Electronic Circuits

      Vol:
    E101-C No:3
      Page(s):
    161-169

    This paper presents a fully integrated 32-MHz relaxation oscillator (ROSC) capable of sub-1-µs start-up time operation for low-power intermittent VLSI systems. The proposed ROSC employs current mode architecture that is different from conventional voltage mode architecture. This enables compact and fast switching speed to be achieved. By designing transistor sizes equally between one in a bias circuit and another in a voltage to current converter, the effect of process variation can be minimized. A prototype chip in a 0.18-µm CMOS demonstrated that the ROSC generates a stable clock frequency of 32.6 MHz within 1-µs start-up time. Measured line regulation and temperature coefficient were ±0.69% and ±0.38%, respectively.

21-25hit(25hit)