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12021-12040hit(42807hit)

  • On the Cross-Correlation Distributions of p-Ary m-Sequences and Their Decimated Sequences

    Sung-Tai CHOI  Jong-Seon NO  

     
    INVITED PAPER

      Vol:
    E95-A No:11
      Page(s):
    1808-1818

    In this paper, we analyze the existing results to derive the cross-correlation distributions of p-ary m-sequences and their decimated sequences for an odd prime p and various decimations d. Based on the previously known results, a methodology to obtain the distribution of their cross-correlation values is also formulated.

  • Normalization Method of Gradient Vector in Frequency Domain Steepest Descent Type Adaptive Algorithm

    Yusuke KUWAHARA  Yusuke IWAMATSU  Kensaku FUJII  Mitsuji MUNEYASU  Masakazu MORIMOTO  

     
    LETTER-Digital Signal Processing

      Vol:
    E95-A No:11
      Page(s):
    2041-2045

    In this paper, we propose a normalization method dividing the gradient vector by the sum of the diagonal and two adjoining elements of the matrix expressing the correlation between the components of the discrete Fourier transform (DFT) of the reference signal used for the identification of unknown system. The proposed method can thereby improve the estimation speed of coefficients of adaptive filter.

  • Route Computation Method for Secure Delivery of Secret Shared Content

    Nagao OGINO  Takuya OMI  Hajime NAKAMURA  

     
    PAPER-Network

      Vol:
    E95-B No:11
      Page(s):
    3456-3463

    Secret sharing schemes have been proposed to protect content by dividing it into many pieces securely and distributing them over different locations. Secret sharing schemes can also be used for the secure delivery of content. The original content cannot be reconstructed by the attacker if the attacker cannot eavesdrop on all the pieces delivered from multiple content servers. This paper aims to obtain secure delivery routes for the pieces, which minimizes the probability that all the pieces can be stolen on the links composing the delivery routes. Although such a route optimization problem can be formulated using an ILP (Integer Linear Programming) model, optimum route computation based on the ILP model requires large amounts of computational resources. Thus, this paper proposes a lightweight route computation method for obtaining suboptimum delivery routes that achieve a sufficiently small probability of all the pieces being stolen. The proposed method computes the delivery routes successively by using the conventional shortest route algorithm repeatedly. The distance of the links accommodating the routes that have already been calculated is adjusted iteratively and utilized for calculation of the new shortest route. The results of a performance evaluation clarify that sufficiently optimum routes can be computed instantly even in practical large-scale networks by the proposed method, which adjusts the link distance strictly based on the risk level at the considered link.

  • A Novel Approach Based on Adaptive Long-Term Sub-Band Entropy and Multi-Thresholding Scheme for Detecting Speech Signal

    Kun-Ching WANG  

     
    LETTER-Speech and Hearing

      Vol:
    E95-D No:11
      Page(s):
    2732-2736

    Conventional entropy measure is derived from full-band (range from 0 Hz to 4 kHz); however, it can not clearly describe the spectrum variability during voice-activity. Here we propose a novel concept of adaptive long-term sub-band entropy ( ALT-SubEnpy ) measure and combine it with a multi-thresholding scheme for voice activity detection. In detail, the ALT-SubEnpy measure developed with four part parameters of sub-entropy which uses different long-term spectral window length at each part. Consequently, the proposed ALT-SubEnpy -based algorithm recursively updates the four adaptive thresholds on each part. The proposed ALT-SubEnpy-based VAD method is shown to be an effective method while working at variable noise-level condition.

  • Method for Evaluating Performance of Wipers Based on Visibility Open Access

    Takashi KITAYAMA  Mikiko KAWASUMI  Hatsuo YAMASAKI  Tomoaki NAKANO  Shin YAMAMOTO  Muneo YAMADA  Yuta DOI  

     
    INVITED PAPER

      Vol:
    E95-C No:11
      Page(s):
    1716-1723

    There is no clear criterion yet for evaluating wipers based on performances of wiping raindrops and visibility in forward view. In the visibility evaluation in rainy driving, it is important to examine spatial frequency and contrast of objects in forward view. Spatial frequency and contrast of image which were affected by raindrops are calculated based on them of background board which were printed stripe patterns. Variations with time of power of analysed frequency and decreased contrast are synchronized with motion of the wiper for the all experimental cases. Moreover, we executed questionnaire, and evaluated the view of the background board. These results show that the proposed methods have been validated in evaluation with wiping performance.

  • Efficient Fully Simulatable Oblivious Transfer from the McEliece Assumptions

    Bernardo MACHADO DAVID  Anderson C.A. NASCIMENTO  Rafael T. DE SOUSA, JR.  

     
    PAPER-Cryptography and Information Security

      Vol:
    E95-A No:11
      Page(s):
    2059-2066

    We introduce an efficient fully simulatable construction of oblivious transfer based on the McEliece assumptions in the common reference string model. This is the first efficient fully simulatable oblivious protocol based on coding assumptions. Moreover, being based on the McEliece assumptions, the proposed protocol is a good candidate for the post-quantum scenario.

  • Flexible Combination of Time-Domain Lapped Transforms with Various Downsampling Factors

    Yuichi TANAKA  Madoka HASEGAWA  Shigeo KATO  

     
    PAPER-Digital Signal Processing

      Vol:
    E95-A No:11
      Page(s):
    2049-2058

    In this paper, we present a method to combine lapped transforms with various downsampling factors. The factor is changed depending on a local feature of a given signal, and it can be realized by using time-domain lapped transforms. In image coding application, our method maintains good image coding performance for a wide range of bitrates and fills the gap between undersampled and critically-/oversampled systems.

  • A CMOS SRAM Test Cell Design Using Selectively Metal-Covered Transistors for a Laser Irradiation Failure Analysis

    Hiroshi HATANO  

     
    BRIEF PAPER-Electronic Circuits

      Vol:
    E95-C No:11
      Page(s):
    1827-1829

    A laser irradiation experiment for photocurrent induced failure investigations was described. In order to focus a laser beam on a desired transistor, novel test circuit structures using selectively metal-covered transistors were proposed. Photocurrent induced upset failures were successfully observed in fabricated CMOS SRAM test cells. Results were discussed with SPICE simulations.

  • Some Properties of Binary Matrices and Quasi-Orthogonal Signals Based on Hadamard Equivalence

    Ki-Hyeon PARK  Hong-Yeop SONG  

     
    PAPER-Sequences

      Vol:
    E95-A No:11
      Page(s):
    1862-1872

    We apply the Hadamard equivalence to all the binary matrices of the size mn and study various properties of this equivalence relation and its classes. We propose to use HR-minimal as a representative of each equivalence class, and count and/or estimate the number of HR-minimals of size mn. Some properties and constructions of HR-minimals are investigated. Especially, we figure that the weight on an HR-minimal's second row plays an important role, and introduce the concept of Quasi-Hadamard matrices (QH matrices). We show that the row vectors of mn QH matrices form a set of m binary vectors of length n whose maximum pairwise absolute correlation is minimized over all such sets. Some properties, existence, and constructions of Quasi-orthogonal sequences are also discussed. We also give a relation of these with cyclic difference sets. We report lots of exhaustive search results and open problems, one of which is equivalent to the Hadamard conjecture.

  • Fair Share – Aware Active Queue Management for Heterogeneous Flows –

    Kyungkoo JUN  

     
    LETTER-Internet

      Vol:
    E95-B No:11
      Page(s):
    3590-3593

    An active queue management (AQM) scheme is proposed to reduce throughput bias for UDP flows over TCP. It is argued that existing AQM methods partially involve a flow-indifferent factor that does not take into account of bandwidth usage of flows when they determine packet drop, thus resulting in unfairness. The proposed scheme replaces the flow-indifferent part with a flow-wise one by approximating per-flow fair share, which permits the discrimination of unresponsive flows. Since it is a stateless process, it avoids the overhead of tracking the statistics of flows and implementation is simple. A performance evaluation shows that it effectively limits the bandwidth of unresponsive flows to their fair share of bandwidth. In addition, it can also encourage RTT-fairness among TCP flows with different delays.

  • FOREWORD

    Akio MIYAZAKI  Tomoaki KIMURA  

     
    FOREWORD

      Vol:
    E95-A No:11
      Page(s):
    1945-1945
  • Correlation Measure of Order k and Linear Complexity Profile of Legendre-Sidelnikov Sequences

    Ming SU  Arne WINTERHOF  

     
    PAPER-Sequences

      Vol:
    E95-A No:11
      Page(s):
    1851-1854

    Linear complexity profile and correlation measure of order k are important pseudorandomness measures for sequences used in cryptography. We study both measures for a class of binary sequences called Legendre-Sidelnikov sequences. The proofs involve character sums.

  • A Memory-Efficient Bit-Split Pattern Matching Architecture Using Shared Match Vectors for Deep Packet Inspection

    HyunJin KIM  

     
    LETTER-Network Management/Operation

      Vol:
    E95-B No:11
      Page(s):
    3594-3596

    This paper proposes a bit-split string matcher architecture for a memory-efficient hardware-based parallel pattern matching engine. In the proposed bit-split string matcher, multiple finite-state machine (FSM) tiles share match vectors to reduce the required number of stored match vectors. By decreasing the memory size for storing match vectors, the total memory requirement can be minimized.

  • A Switchable Circular Polarization Microstrip Antenna Using a Varactor Diode

    Tae-Hak LEE  Jung-Woo BAIK  Junho CHOI  Young-Sik KIM  

     
    LETTER-Antennas and Propagation

      Vol:
    E95-B No:11
      Page(s):
    3597-3600

    In this letter a circular polarization microstrip antenna with switchable polarization is proposed. The switchable polarization sense characteristic is realized via a shunt connected varactor tuning diode. The appropriate capacitance of the diode at the reverse bias voltage can alter two circular polarizations, as the tuning diode, which is located near the rectangular slot in the circular patch, is utilized in a perturbation element. The switchable polarization is analyzed using the equivalent circuit model representing the resonances of each orthogonal mode. Simulation, calculated, and measured results agree well.

  • Effects of Channel Estimation Error and Interference on BER in the MIMO Zero-Forcing Receiver

    Sang Goo KIM  Dongweon YOON  Janghoon OH  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E95-B No:11
      Page(s):
    3605-3608

    The Multiple-Input Multiple-Output (MIMO) Zero-Forcing (ZF) receiver requires accurate Channel State Information (CSI), which is impacted by channel estimation error, to perform properly. Moreover, interference occurs due to the change of channel coefficients between the channel estimation events in fading channels. Thus, in practice, both channel estimation error and interference greatly influence Bit Error Rate (BER) performance. In this letter, we derive an Signal-to-Interference-and-Noise Ratio (SINR) expression considering both channel estimation error and interference and develop approximate closed-form BER expressions of M-PSK and M-QAM for the MIMO ZF receiver in Nakagami-m fading channels. We then analyze the effects of channel estimation error, interference, and the numbers of transmit and receive antennas.

  • Study on Surface Characteristic of the Copper Nitride Films by Absorbed Oxygen Open Access

    Musun KWAK  Jongho JEON  Kyoungri KIM  Yoonseon YI  Sangjin AN  Donsik CHOI  Youngseok CHOI  Kyongdeuk JEONG  

     
    INVITED PAPER

      Vol:
    E95-C No:11
      Page(s):
    1744-1748

    The copper nitride surface characteristics according to atmospheric pressure plasma (APP) and excimer ultraviolet (EUV) treatment were compared using XPS and AFM. As the result of XPS analysis result, in C1s, the organic material removal effect was greater for EUV treatment than for APP, and the oxygen content was found to be low. In Cu (933 eV) area, the shoulder peak of Cu compound was detected, and the reduction was greater for EUV processing than for APP. In the AFM phase image which could be analyzed using the superficial viscoelasticity, the same trend was observed. On the copper nitride surface, the weak boundary O layer is formed according to the clean processing, and such phenomenon was interpreted as a factor for lowering the affinity with polymer.

  • Numerical Modeling; Thickness Dependence of J-V Characteristic for Multi-Layered OLED Device Open Access

    Sang-Gun LEE  Hong-Seok CHOI  Chang-Wook HAN  Seok-Jong LEE  Yoon-Heung TAK  Byung-Chul AHN  

     
    INVITED PAPER

      Vol:
    E95-C No:11
      Page(s):
    1756-1760

    A numerical model of multi-layered organic light emitting diode (OLED) is presented in this paper. The current density-voltage (J-V) model for OLED was performed by using the injection-limited current and bulk-limited current. The mobility equation was based on the field dependent model, so called “Poole-Frenkel mobility model.” The accuracy of this simulation was represented by comparing to the experimental results with a variable of EML thickness of multi-layered OLED device. There are two hetero-junction models which should be dealt with in the simulation. The Langevin recombination rate of electron and hole is also calculated through the device simulation.

  • Risk-Based Semi-Supervised Discriminative Language Modeling for Broadcast Transcription

    Akio KOBAYASHI  Takahiro OKU  Toru IMAI  Seiichi NAKAGAWA  

     
    PAPER-Speech and Hearing

      Vol:
    E95-D No:11
      Page(s):
    2674-2681

    This paper describes a new method for semi-supervised discriminative language modeling, which is designed to improve the robustness of a discriminative language model (LM) obtained from manually transcribed (labeled) data. The discriminative LM is implemented as a log-linear model, which employs a set of linguistic features derived from word or phoneme sequences. The proposed semi-supervised discriminative modeling is formulated as a multi-objective optimization programming problem (MOP), which consists of two objective functions defined on both labeled lattices and automatic speech recognition (ASR) lattices as unlabeled data. The objectives are coherently designed based on the expected risks that reflect information about word errors for the training data. The model is trained in a discriminative manner and acquired as a solution to the MOP problem. In transcribing Japanese broadcast programs, the proposed method reduced relatively a word error rate by 6.3% compared with that achieved by a conventional trigram LM.

  • High-Speed Low-Power Boosted Level Converters for Dual Supply Systems

    Sang-Keun HAN  KeeChan PARK  Young-Hyun JUN  Bai-Sun KONG  

     
    BRIEF PAPER-Electronic Circuits

      Vol:
    E95-C No:11
      Page(s):
    1824-1826

    This paper introduces novel high-speed and low-power boosted level converters for use in dual-supply systems. The proposed level converters adopt a voltage boosting at the gate of pull-down transistors to improve driving speed and reduce contention problem. Comparison results in a 0.13-µm CMOS process indicated that the proposed level converters provided up to 70% delay reduction with up to 57% power-delay product (PDP) reduction as compared to conventional level converters.

  • A Quantitative Evaluation Method for Luminance and Color Uniformity of a Display Screen Based on Human Perception Open Access

    Kunihiko NAGAMINE  Satoshi TOMIOKA  Tohru TAMURA  Yoshihide SHIMPUKU  

     
    INVITED PAPER

      Vol:
    E95-C No:11
      Page(s):
    1699-1706

    We developed a quantitative evaluation method for luminance and color uniformity on a display screen. In this paper, we report the analysis result of a viewer perception of luminance and color uniformity. In experiments, observers subjectively evaluated Mura images which were showed on the light emitting diode (LED) backlight screen by adjusting the luminance of each LED. We measured the luminance and color distributions of the Mura images by a 2D colorimeter, then, the measured data was converted into S-CIELAB. In S-CIELAB calculations, two dimensional MTF (Modulation Transfer Function) of human eye were used in which anisotropic properties of the spatial frequency response of human vision were considered. Some indexes for a quantitative evaluation model were extracted by the image processing. The significant indexes were determined by the multiple regression analysis to quantify the degree of uniformity of the backlight screen. The luminance uniformity evaluation model and color uniformity evaluation model were derived from this analysis independently. In addition, by integrating both of these models we derived a quantitative evaluation model for luminance and color unevenness simultaneously existing on the screen.

12021-12040hit(42807hit)