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[Keyword] ASTA(10hit)

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  • Movement Awareness-Adaptive Spatio Temporal Noise Reduction in Video

    Sangwoo AHN  Jongjoo PARK  Linbo LUO  Jongwha CHONG  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E97-D No:2
      Page(s):
    380-383

    In this letter, we present an efficient video matching-based denoising method. Two main issues are addressed in this paper: the matched points and the denoising algorithm based on an adaptive spatial temporal filter. Unlike previous algorithms, our method adaptively selects reference pixels within spatially and temporally neighboring frames. Our method uses more information about matched pixels on neighboring frames than other methods. Therefore, the proposal enhanced the accuracy of video denoising. Simulation results show that the proposed method produces cleaner and sharper images.

  • A Digital TRNG Based on Cross Feedback Ring Oscillators

    Lijuan LI  Shuguo LI  

     
    PAPER-Hardware Based Security

      Vol:
    E97-A No:1
      Page(s):
    284-291

    In this paper, a new digital true random number generator based on Cross Feedback Ring Oscillators (CFRO) is proposed. The random sources of CFRO lie in delay variations (jitter), unpredictable transition behaviors as well as metastability. The CFRO is proved to be truly random by restarting from the same initial states. Compared with the so-called Fibonacci Ring Oscillator (FIRO) and Galois Ring Oscillator (GARO), the CFRO needs less than half of their time to accumulate relatively high entropy and enable extraction of one random bit. Only a simple XOR corrector is used to reduce the bias of output sequences. TRNG based on CFRO can be run continuously at a constant high speed of 150Mbps. For higher security, the TRNG can be set in stateless mode at a cost of slower speed of 10Mbps. The total logical resources used are relatively small and no special placement and routing is needed. The TRNG both in continuous mode and in stateless mode can pass the NIST tests and the DIEHARD tests.

  • Metastable Ordered Phase Formation in CoPt and Co3Pt Alloy Thin Films Epitaxially Grown on Single-Crystal Substrates

    Mitsuru OHTAKE  Daisuke SUZUKI  Fumiyoshi KIRINO  Masaaki FUTAMOTO  

     
    REVIEW PAPER

      Vol:
    E96-C No:12
      Page(s):
    1460-1468

    CoPt and Co3Pt alloy thin films are prepared on MgO(111), SrTiO3(111), and Al2O3(0001) single-crystal substrates by varying the substrate temperature in a range from room temperature to 600°C by using an ultra-high vacuum radio-frequency magnetron sputtering system. The formation of metastable ordered phase and the structural thermal stability are briefly investigated. CoPt and Co3Pt films with the close-packed plane parallel to the substrate surface grow epitaxially on these oxide single-crystal substrates. CoPt epitaxial films are also formed by employing Pt, Pd, Cu, Cr, Ti, and Ru underlayers hetero-epitaxially grown on MgO(111) substrates. The crystal structure is evaluated by considering the order degree and the atomic stacking sequence of close-packed plane. Metastable ordered phases of L11, Bh, and D019 are preferentially formed in the CoPt and the Co3Pt films deposited around 300°C. Metastable ordered phase formation is influenced by the substrate temperature, the film composition, and the underlayer material. With increasing the substrate temperature up to around 300°C, the order degree increases. As the substrate temperature further increases, the order degree decreases. Annealing a disordered film at 300°C does not effectively enhance ordering. The CoPt and the Co3Pt films which include metastable ordered phases have flat surfaces and show strong perpendicular magnetic anisotropies reflecting the magnetocrystalline anisotropies of ordered crystals.

  • A Study about Wireless Network Communication Performance at the Coastal Area for Underwater Monitoring Sensor Networks

    Kuniaki KAWABATA  Takafumi KOBAYASHI  Fumiaki TAKEMURA  Hideo SATO  Tsuyoshi SUZUKI  

     
    LETTER

      Vol:
    E93-B No:11
      Page(s):
    2956-2958

    This manuscript reported basic examination results of the wireless network communication performance at the coast. We consider that underwater environment condition monitoring is a sort of likely typical application for ubiquitous sensor networks. The result of the experiment shows the performance of the wireless network communication at the coastal area.

  • A Voltage Controlled Oscillator with Up Mode Type Miller-Integrator

    Mitsutoshi YAHARA  Kuniaki FUJIMOTO  Hirofumi SASAKI  

     
    LETTER-Electronic Circuits

      Vol:
    E88-C No:12
      Page(s):
    2385-2387

    In this paper, we propose a voltage controlled oscillator (VCO) with up mode type Miller-integrator. The controlled voltage of this VCO can continuously change 0 V center in the positive and negative bidirection. Also, the relationship between control voltage and oscillating frequency shows the good linearity, and the calculated and the measured values agree well.

  • A Parallel Flop Synchronizer and the Handshake Interface for Bridging Asynchronous Domains

    Suk-Jin KIM  Jeong-Gun LEE  Kiseon KIM  

     
    PAPER-Logic Synthesis

      Vol:
    E87-A No:12
      Page(s):
    3166-3173

    Inter-domain communications on a chip require a synchronizer to resolve the timing problems between an input and a clock of a destination. This paper presents a parallel flop synchronizer and its interface circuit for transferring asynchronous data to the clock domain. The proposed scheme uses a bank of independent two-flops in parallel and supports a two-phase handshake protocol. Compared to the conventional two-flop synchronizer, performance analysis shows that the proposed scheme can reduce latency up to one and a half of clock cycles while retaining its safety to a tolerable level. All designs have been implemented in a 0.25 µm CMOS technology to verify performance analysis of the proposed synchronization.

  • An Efficient Lip-Reading Method Robust to Illumination Variations

    Jinyoung KIM  Joohun LEE  Katsuhiko SHIRAI  

     
    LETTER-Speech and Hearing

      Vol:
    E85-A No:9
      Page(s):
    2164-2168

    In this paper, for real-time automatic image transform based lip-reading under illumination variations, an efficient (smaller feature data size) and robust (better recognition under different lighting conditions) method is proposed. Image transform based approach obtains a compressed representation of image pixel values of speaker's mouth and is reported to show superior lip-reading performance. However, this approach inevitably produces large feature vectors relevant to lip information to require much computation time for lip-reading even when principal component analysis (PCA) is applied. To reduce the necessary dimension of feature vectors, the proposed method folded the lip image based on its symmetry in a frame image. This method also compensates the unbalanced illumination between the left and the right lip areas. Additionally, to filter out the inter-frame time-domain spectral distortion of each pixel contaminated by illumination noise, our method adapted the hi-pass filtering on the variations of pixel values between consecutive frames. In the experimental results performed on database recorded at various lighting conditions, the proposed lip-folding or/and inter-frame filtering reduced much the necessary number of feature data, principal components in this work, and showed superior recognition rate compared to the conventional method.

  • Multi-Recastable Ticket Schemes for Electronic Voting

    Chun-I FAN  Chin-Laung LEI  

     
    PAPER-Information Security

      Vol:
    E81-A No:5
      Page(s):
    940-949

    Multi-recast techniques make it possible for a voter to participate in a sequence of different designated votings by using only one ticket. In a multi-recastable ticket scheme for electronic voting, every voter of a group can obtain an m-castable ticket (m-ticket), and through the m-ticket, the voter can participate in a sequence of m different designated votings held in this group. The m-ticket contains all possible intentions of the voter in the sequence of votings, and in each of the m votings, a voter casts his vote by just making appropriate modifications to his m-ticket. The authority cannot produce both the opposite version of a vote cast by a voter in one voting and the succeeding uncast votes of the voter. Only one round of registration action is required for a voter to request an m-ticket from the authority. Moreover, the size of such an m-ticket is not larger than that of an ordinary vote. It turns out that the proposed scheme greatly reduces the network traffic between the voters and the authority during the registration stages in a sequence of different votings, for example, the proposed method reduces the communication traffic by almost 80% for a sequence of 5 votings and by nearly 90% for a sequence of 10 votings.

  • KASTAM: A Model of Kanji Learning for Knowledge Stability

    Toshihiro HAYASHI  Yukuo HAYASHIDA  Yoneo YANO  

     
    LETTER

      Vol:
    E78-A No:5
      Page(s):
    587-588

    This paper describes a model of kanji (Chinese characters) learning, called KASTAM (Knowledge Acquisition and STAbility Model), in order to develop a CAI system which supports a student to stabilize her/his kanji knowledge. KASTAM can handle kanji learning as complementary acquisition and stability processes of kanji knowledge.

  • A Voltage Controlled Astable Multivibrator with Miller-Integrator

    Hirofumi SASAKI  Kuniaki FUJIMOTO  Mitsutoshi YAHARA  

     
    LETTER

      Vol:
    E78-A No:2
      Page(s):
    196-198

    In this letter, we propose a simple voltage controlled oscillator (VCO) with circuitry combining a Miller integrator and an RS flip-flop circuit. With the VCO, the control voltage can be varied over a broad range, and the oscillation frequency varies in proportion to the control voltage. The maximum voltage is up to 1000 times the minimum, and the calculated design values and measured values agree well. This VCO can be applied to FM modulators, FSK modulators, and other systems.