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[Keyword] Q(6809hit)

1861-1880hit(6809hit)

  • 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.

  • 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.

  • 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 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.

  • Reduced Complexity MLSD Equalizers Based on Bidirectional DFEs

    Jangwoo PARK  Youngsun HA  Wonzoo CHUNG  

     
    PAPER-Fundamental Theories for Communications

      Vol:
    E95-B No:11
      Page(s):
    3432-3436

    We propose a reduced complexity maximum likelihood sequence detection (MLSD) equalizer for wireless communications using bidirectional decision feedback equalizers (DFEs). We apply reduced-length two-level estimates produced by a bidirectional DFE. Therefore, the computationally expensive MLSD algorithm is applied sparingly for two-level signals with the effective channel length shorter than the original channel, regardless of the original constellation size of the symbols. Simulation results show that the proposed algorithm outperforms existing combination schemes based on bidirectional DFEs, especially for large constellations.

  • A CMOS Current-Mode S-Shape Correction Circuit with Shape-Adjustable Control

    Kuo-Jen LIN  Chih-Jen CHENG  Hsin-Cheng SU  Jwu-E CHEN  

     
    PAPER

      Vol:
    E95-C No:11
      Page(s):
    1730-1736

    A CMOS current-mode S-shape correction circuit with shape-adjustable control is proposed for suiting different LCD panel's characteristics from different manufactures. The correction shape is divided into three segments for easy curve-fitting using three lower order polynomials. Each segment could be realized by a corresponding current-mode circuit. The proposed circuit consists of several control points which are designed for tuning the correction shape. The S-shape correction circuit was fabricated using the 0.35 µm TSMC CMOS technology. The measured input dynamic range of the circuit is from 0 µA to 220 µA. The -3 dB bandwidth of the circuit is up to 262 MHz in a high input current region.

  • Alternative Method for Determining Permeability of a Ferrite Core by Using a Combined Microstrip Line-Coaxial Conductor

    Takanobu AOYAMA  Masafumi KATSUDA  Tomohiko KANIE  Takashi TAKEO  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E95-C No:11
      Page(s):
    1769-1775

    An equivalent network analysis for an arrangement that combines a microstrip line and coaxial conductor for the purpose of measuring permeability is discussed in this paper. The measurement circuit used consists of a coaxial conductor with a sample housed inside and a short microstrip line connected to both sides. The coaxial conductor is composed of an electrically grounded coaxial metal pipe with open ends and a center conductor. Equivalent networks for this arrangement are investigated to determine the complex permeability from the impedance of the measurement circuit. We have employed a π network composed of a resistor and an inductor connected in series, and shunt capacitors as the equivalent circuit for the measurement portion. It has been found that the measurement error ratio of less than a few percent can be obtained for most frequency ranges of 10 MHz to 500 MHz.

  • Theoretical Considerations for Maintaining the Performance of Composite Web Services

    Shinji KIKUCHI  Yoshihiro KANNA  Yohsuke ISOZAKI  

     
    PAPER-Data Engineering, Web Information Systems

      Vol:
    E95-D No:11
      Page(s):
    2634-2650

    In recent years, there has been an increasing demand with regard to available elemental services provided by independent firms for compositing new services. Currently, however, whenever it is difficult to maintain the required level of quality of a new composite web service, assignment of the new computer's resources as provisioning at the data center is not always effective, especially in the area of performance for composite web service providers. Thus, a new approach might be required. This paper presents a new control method aiming to maintain the performance requirements for composite web services. There are three aspects of our method that are applied: first of all, the theory of constraints (TOC) proposed by E.M. Goldratt ; secondly, an evaluation process in the non-linear feed forward controlling method: and finally multiple trials in applying policies with verification. In particular, we will discuss the architectural and theoretical aspects of the method in detail, and will show the insufficiency of combining the feedback controlling approach with TOC as a result of our evaluation.

  • Zero-Cross-Correlation Properties of Asymmetric ZCZ Sequence Sets

    Kosuke OMATA  Hideyuki TORII  Takahiro MATSUMOTO  

     
    LETTER-Sequences

      Vol:
    E95-A No:11
      Page(s):
    1926-1930

    Recently, asymmetric zero-correlation zone (A-ZCZ) sequence sets that are composed of several sequence subsets have been proposed. In A-ZCZ sequence sets, the zero-cross-correlation zone (ZCCZ) length between different sequence subsets is larger than the zero-correlation zone (ZCZ) length in each sequence subset. However, the ZCCZ length between different sequence subsets was not precisely shown in previous studies. The present letter shows precisely the ZCCZ length between different sequence subsets. This information is useful for estimating the magnitude of inter-cell interference when designing approximately synchronized code-division multiple-access (AS-CDMA) systems.

  • Design of a New 4-Dimensional Constellation-Rotation Modulation Method for DVB-NGH

    Taejin JUNG  Hyoungsoo LIM  

     
    LETTER-Terrestrial Wireless Communication/Broadcasting Technologies

      Vol:
    E95-B No:11
      Page(s):
    3625-3628

    In this letter, we propose a new 4-dimensional constellation-rotation (CR) modulation method that achieves diversity gain of 4 in Rayleigh fading channels. The proposed scheme consists of two consecutive CR operations for QAM symbols unlike the conventional 2-dimensional CR method based on only one CR operation. Computer simulation results show that the new method exhibits much better performance than the conventional one in terms of code rate and channel erasure ratio.

  • New Infinite Classes of Optimal (υ, {k, 6}, 1, Q) Optical Orthogonal Codes via Quadratic Residues

    Xiaorun ZHONG  Dianhua WU  Pingzhi FAN  

     
    PAPER-Sequences

      Vol:
    E95-A No:11
      Page(s):
    1827-1834

    Variable-weight optical orthogonal codes (OOCs) were introduced by Yang for multi-media optical CDMA systems with multiple quality of service (QoS) requirements. Some works had been done on the existence of optimal (υ,W,1,Q)-OOCs for W ∈ {{3,4}, {3,5}, {4,5}}. In this paper, by using quadratic residues, seven new infinite classes of optimal (υ,{k,6},1,Q)-OOCs for k ∈ {3,4} are constructed.

  • Burst Error Resilient Channel Coding for SVC over Mobile Networks

    GunWoo KIM  Yongwoo CHO  Jihyeok YUN  DougYoung SUH  

     
    LETTER-Multimedia Environment Technology

      Vol:
    E95-A No:11
      Page(s):
    2032-2035

    This paper proposes Burst Error Resilient coding (BRC) technology in mobile broadcasting network. The proposed method utilizes Scalable Video Coding (SVC) and Forward Error Correction (FEC) to overcome service outage due to burst loss in mobile network. The performance evaluation is performed by comparing PSNR of SVC and the proposed method under MBSFN simulation channel. The simulation result shows PSNR of SVC equal error protection (EEP), unequal error protection (UEP) and proposed BRC using Raptor FEC code.

  • Invertible Color-to-Monochrome Conversion Based on Color Quantization with Lightness Constraint

    Go TANAKA  Noriaki SUETAKE  Eiji UCHINO  

     
    LETTER-Image

      Vol:
    E95-A No:11
      Page(s):
    2093-2097

    A method obtaining a monochrome image which can rebuild colors is proposed. In this method, colors in an input image are quantized under a lightness constraint and a palette, which represents relationship between quantized colors and gray-levels, is generated. Using the palette, an output monochrome image is obtained. Experiments show that the proposed method obtains good monochrome and rebuilt color images.

  • No-Reference Quality Estimation for Video-Streaming Services Based on Error-Concealment Effectiveness

    Toru YAMADA  Yoshihiro MIYAMOTO  Takao NISHITANI  

     
    PAPER-Multimedia Environment Technology

      Vol:
    E95-A No:11
      Page(s):
    2007-2014

    This paper proposes a video-quality estimation method based on a no-reference model for realtime quality monitoring in video-streaming services. The proposed method analyzes both bitstream information and decoded pixel information to estimate video-quality degradation by transmission errors. Video quality in terms of a mean squared error (MSE) between degraded video frames and error-free video frames is estimated on the basis of the number of impairment macroblocks in which the quality degradation has not been possible to be concealed. Error-concealment effectiveness is evaluated using motion information and luminance discontinuity at the boundaries of impairment regions. Simulation results show a high correlation (correlation coefficients of 0.93) between the actual MSE and the number of macroblocks in which error concealment has not been effective. These results show that the proposed method works well in reatime quality monitoring for video-streaming services.

  • Fractionally Spaced Equalization for Asynchronous Broadband Analog Network Coding

    Zhaoxi FANG  Feng LIANG  Shaozhong ZHANG  Xiaolin ZHOU  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E95-B No:11
      Page(s):
    3617-3620

    Timing asynchronism strongly degrades the performance of analog network coded (ANC) bi-directional transmission. This letter investigates receiver design for asynchronous broadband bi-directional transmission over frequency selective fading channels. Based on time domain oversampling, we propose fractionally spaced frequency domain minimum mean square error (MMSE) equalizers for bi-directional ANC based on orthogonal frequency division multiplexing (OFDM) and cyclic prefixed single carrier (CP-SC) radio access. Simulation results show that the proposed fractionally spaced equalizer (FSE) can eliminate the negative effect of timing misalignment in bi-directional transmissions.

  • Even-Shift Orthogonal Arrays

    Shinya MATSUFUJI  Takahiro MATSUMOTO  Pingzhi FAN  

     
    LETTER-Sequences

      Vol:
    E95-A No:11
      Page(s):
    1937-1940

    The even-shift orthogonal sequence whose out-of-phase aperiodic autocorrelation function takes zero at any even shifts is generalized to multi-dimension called even-shift orthogonal array (E-array), and the logic function of E-array of power-of-two length is clarified. It is shown that E-array can be constructed by complementary arrays, which mean pairs of arrays that the sum of each aperiodic autocorrelation function at the same phase shifts takes zero at any shift except zero shift, as well as the one-dimensional case. It is also shown that the number of mates of E-array with which the cross correlation function between E-arrays takes zero at any even shifts is equal to the dimension. Furthermore it is investigated that E-array possesses good aperiodic autocorrelation that the rate of zero correlation values to array length approaches one as the dimension becomes large.

  • Automatic Parameter Adjustment Method for Audio Equalizer Employing Interactive Genetic Algorithm

    Yuki MISHIMA  Yoshinobu KAJIKAWA  

     
    LETTER-Engineering Acoustics

      Vol:
    E95-A No:11
      Page(s):
    2036-2040

    In this paper, we propose an automatic parameter adjustment method for audio equalizers using an interactive genetic algorithm (IGA). It is very difficult for ordinary users who are not familiar with audio devices to appropriately adjust the parameters of audio equalizers. We therefore propose a system that can automatically adjust the parameters of audio equalizers on the basis of user's evaluation of the reproduced sound. The proposed system utilizes an IGA to adjust the gains and Q values of the peaking filters included in audio equalizers. Listening test results demonstrate that the proposed system can appropriately adjust the parameters on the basis of the user's evaluation.

  • 16-QAM Golay, Periodic and Z- Complementary Sequence Sets

    Fanxin ZENG  Xiaoping ZENG  Zhenyu ZHANG  Guixin XUAN  

     
    LETTER-Information Theory

      Vol:
    E95-A No:11
      Page(s):
    2084-2089

    In contemporary communications, Golay, periodic and Z- complementary sequence sets play a very important role, since such sequence sets possess impulse-like or zero correlation zone (ZCZ) autocorrelation. On the other hand, the advantages of the signals over the quadrature amplitude modulation (QAM) constellation are more and more prominent. Hence, the design of such sequence sets over the QAM constellation has turned into one of the all-important issues in communications. Therefore, the construction methods of such sequence sets over the 16-QAM constellation are investigated, in this letter, and our goals are arrived at by the known quaternary Golay, periodic and Z- complementary sequence sets. Finally, many examples illuminate the validity of the proposed methods.

1861-1880hit(6809hit)