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[Keyword] order(489hit)

101-120hit(489hit)

  • Biped: Bidirectional Prediction of Order Violations

    Xi CHANG  Zhuo ZHANG  Yan LEI  Jianjun ZHAO  

     
    PAPER-Software Engineering

      Pubricized:
    2014/10/29
      Vol:
    E98-D No:2
      Page(s):
    334-345

    Concurrency bugs do significantly affect system reliability. Although many efforts have been made to address this problem, there are still many bugs that cannot be detected because of the complexity of concurrent programs. Compared with atomicity violations, order violations are always neglected. Efficient and effective approaches to detecting order violations are therefore in urgent need. This paper presents a bidirectional predictive trace analysis approach, BIPED, which can detect order violations in parallel based on a recorded program execution. BIPED collects an expected-order execution trace into a layered bidirectional prediction model, which intensively represents two types of expected-order data flows in the bottom layer and combines the lock sets and the bidirectionally order constraints in the upper layer. BIPED then recognizes two types of candidate violation intervals driven by the bottom-layer model and then checks these recognized intervals bidirectionally based on the upper-layer constraint model. Consequently, concrete schedules can be generated to expose order violation bugs. Our experimental results show that BIPED can effectively detect real order violation bugs and the analysis speed is 2.3x-10.9x and 1.24x-1.8x relative to the state-of-the-art predictive dynamic analysis approaches and hybrid model based static prediction analysis approaches in terms of order violation bugs.

  • High-Order Bi-orthogonal Fourier Transform and Its Applications in Non-stability Signal Analysis

    Hong WANG  Yue-hua LI  Ben-qing WANG  

     
    LETTER-Fundamentals of Information Systems

      Vol:
    E98-D No:1
      Page(s):
    189-192

    This paper presents a novel signal analysis algorithm, named High-order Bi-orthogonal Fourier Transform (HBFT), which can be seen as an expansion of Fourier transform. The HBFT formula and discrete HBFT formula are derived, some of their main characteristics are briefly discusses. This paper also uses HBFT to analyze the multi-LFM signals, obtain the modulate rate parameters, analyze the high dynamic signals, and obtain the accelerated and varying accelerated motion parameters. The result proves that HBFT is suitable for analysis of the non-stability signals with high-order components.

  • The Numerical Analysis of an Antenna near a Dielectric Object Using the Higher-Order Characteristic Basis Function Method Combined with a Volume Integral Equation

    Keisuke KONNO  Qiang CHEN  

     
    PAPER

      Vol:
    E97-B No:10
      Page(s):
    2066-2073

    The higher-order characteristic basis function method (HO-CBFM) is clearly formulated. HO-CBFM provides results accurately even if a block division is arbitrary. The HO-CBFM combined with a volume integral equation (VIE) is used in the analysis of various antennas in the vicinity of a dielectric object. The results of the numerical analysis show that the HO-CBFM can reduce the CPU time while still achieving the desired accuracy.

  • Efficient Algorithm for Tate Pairing of Composite Order

    Yutaro KIYOMURA  Tsuyoshi TAKAGI  

     
    PAPER-Cryptography and Information Security

      Vol:
    E97-A No:10
      Page(s):
    2055-2063

    Boneh et al. proposed the new idea of pairing-based cryptography by using the composite order group instead of prime order group. Recently, many cryptographic schemes using pairings of composite order group were proposed. Miller's algorithm is used to compute pairings, and the time of computing the pairings depends on the cost of calculating the Miller loop. As a method of speeding up calculations of the pairings of prime order, the number of iterations of the Miller loop can be reduced by choosing a prime order of low Hamming weight. However, it is difficult to choose a particular composite order that can speed up the pairings of composite order. Kobayashi et al. proposed an efficient algorithm for computing Miller's algorithm by using a window method, called Window Miller's algorithm. We can compute scalar multiplication of points on elliptic curves by using a window hybrid binary-ternary form (w-HBTF). In this paper, we propose a Miller's algorithm that uses w-HBTF to compute Tate pairing efficiently. This algorithm needs a precomputation both of the points on an elliptic curve and rational functions. The proposed algorithm was implemented in Java on a PC and compared with Window Miller's Algorithm in terms of the time and memory needed to make their precomputed tables. We used the supersingular elliptic curve y2=x3+x with embedding degree 2 and a composite order of size of 2048-bit. We denote w as window width. The proposed algorithm with w=6=2·3 was about 12.9% faster than Window Miller's Algorithm with w=2 although the memory size of these algorithms is the same. Moreover, the proposed algorithm with w=162=2·34 was about 12.2% faster than Window Miller's algorithm with w=7.

  • Full-Order Observer for Discrete-Time Linear Time-Invariant Systems with Output Delays

    Joon-Young CHOI  

     
    LETTER-Systems and Control

      Vol:
    E97-A No:9
      Page(s):
    1975-1978

    We design a full-order observer for discrete-time linear time-invariant systems with constant output delays. The observer design is based on the output delay model expressed by a two-dimensional state variable, with discrete-time and space independent variables. Employing a discrete-time state transformation, we construct an explicit strict Lyapunov function that enables us to prove the global exponential stability of the full-order observer error system with an explicit estimate of the exponential decay rate. The numerical example demonstrates the design of the full-order observer and illustrates the validity of the exponential stability.

  • Roundoff Noise Minimization for a Class of 2-D State-Space Digital Filters Using Joint Optimization of High-Order Error Feedback and Realization

    Akimitsu DOI  Takao HINAMOTO  Wu-Sheng LU  

     
    PAPER-Digital Signal Processing

      Vol:
    E97-A No:9
      Page(s):
    1918-1925

    For two-dimensional IIR digital filters described by the Fornasini-Marchesini second model, the problem of jointly optimizing high-order error feedback and realization to minimize the effects of roundoff noise at the filter output subject to l2-scaling constraints is investigated. The problem at hand is converted into an unconstrained optimization problem by using linear-algebraic techniques. The unconstrained optimization problem is then solved iteratively by applying an efficient quasi-Newton algorithm with closed-form formulas for key gradient evaluation. Finally, a numerical example is presented to illustrate the validity and effectiveness of the proposed technique.

  • Sound Field Reproduction Using Ambisonics and Irregular Loudspeaker Arrays

    Jorge TREVINO  Takuma OKAMOTO  Yukio IWAYA  Yôiti SUZUKI  

     
    INVITED PAPER

      Vol:
    E97-A No:9
      Page(s):
    1832-1839

    Sound field reproduction systems seek to realistically convey 3D spatial audio by re-creating the sound pressure inside a region enclosing the listener. High-order Ambisonics (HOA), a sound field reproduction technology, is notable for defining a scalable encoding format that characterizes the sound field in a system-independent way. Sound fields sampled with a particular microphone array and encoded into the HOA format can be reproduced using any sound presentation device, typically a loudspeaker array, by using a HOA decoder. The HOA encoding format is based on the spherical harmonic decomposition; this makes it easier to design a decoder for large arrays of loudspeakers uniformly distributed over all directions. In practice, it is seldom possible to cover all directions with loudspeakers placed at regular angular intervals. An irregular array, one where the angular separation between adjacent loudspeakers is not constant, does not perform as well as a regular one when reproducing HOA due to the uneven sampling of the spherical harmonics. This paper briefly introduces the techniques used in HOA and advances a new approach to design HOA decoders for irregular loudspeaker arrays. The main difference between conventional methods and our proposal is the use of a new error metric: the radial derivative of the reconstruction error. Minimizing this metric leads to a smooth reproduction, accurate over a larger region than that achieved by conventional HOA decoders. We evaluate our proposal using the computer simulation of two 115-channel loudspeaker arrays: a regular and an irregular one. We find that our proposal results in a larger listening region when used to decode HOA for reproduction using the irregular array. On the other hand, applying our method matches the high-quality reproduction that can be attained with the regular array and conventional HOA decoders.

  • A Novel Integration of Intensity Order and Texture for Effective Feature Description

    Thao-Ngoc NGUYEN  Bac LE  Kazunori MIYATA  

     
    PAPER-Computer Vision

      Vol:
    E97-D No:8
      Page(s):
    2021-2029

    This paper introduces a novel approach of feature description by integrating the intensity order and textures in different support regions into a compact vector. We first propose the Intensity Order Local Binary Pattern (IO-LBP) operator, which simultaneously encodes the gradient and texture information in the local neighborhood of a pixel. We divide each region of interest into segments according to the order of pixel intensities, build one histogram of IO-LBP patterns for each segment, and then concatenate all histograms to obtain a feature descriptor. Furthermore, multi support regions are adopted to enhance the distinctiveness. The proposed descriptor effectively describes a region at both local and global levels, and thus high performance is expected. Experimental results on the Oxford benchmark and images of cast shadows show that our approach is invariant to common photometric and geometric transformations, such as illumination change and image rotation, and robust to complex lighting effects caused by shadows. It achieves a comparable accuracy to that of state-of-art methods while performs considerably faster.

  • Evaluation of Maximum Redundancy of Data Compression via Substring Enumeration for k-th Order Markov Sources

    Ken-ichi IWATA  Mitsuharu ARIMURA  Yuki SHIMA  

     
    PAPER-Information Theory

      Vol:
    E97-A No:8
      Page(s):
    1754-1760

    Dubé and Beaudoin proposed a lossless data compression called compression via substring enumeration (CSE) in 2010. We evaluate an upper bound of the number of bits used by the CSE technique to encode any binary string from an unknown member of a known class of k-th order Markov processes. We compare the worst case maximum redundancy obtained by the CSE technique for any binary string with the least possible value of the worst case maximum redundancy obtained by the best fixed-to-variable length code that satisfies the Kraft inequality.

  • Parallel Computation of Complex Antennas around the Coated Object Using Iterative Vector Fields Technique

    Ying YAN  Xunwang ZHAO  Yu ZHANG  Changhong LIANG  Zhewang MA  

     
    PAPER

      Vol:
    E97-C No:7
      Page(s):
    661-669

    In this paper, a novel hybrid technique for analyzing complex antennas around the coated object is proposed, which is termed as “iterative vector fields with Physical Optics (PO)”. A closed box is used to enclose the antennas and the complex field vectors on the box' surfaces can then be obtained using Huygens principle. The equivalent electromagnetic currents on Huygens surfaces are computed by Higher-order Method of Moments (HOB-MoM) and the fields scattered from the coated object are calculated by PO method. In addition, the parallel technique based on Message Passing Interface (MPI) and Scalable Linear Algebra Package (ScaLAPACK) is employed so as to accelerate the computation. Numerical examples are presented to validate and to show the effectiveness of the proposed method on solving the practical engineering problem.

  • Effects of Voluntary Movements on Audio-Tactile Temporal Order Judgment

    Atsuhiro NISHI  Masanori YOKOYAMA  Ken-ichiro OGAWA  Taiki OGATA  Takayuki NOZAWA  Yoshihiro MIYAKE  

     
    PAPER-Office Information Systems, e-Business Modeling

      Vol:
    E97-D No:6
      Page(s):
    1567-1573

    The present study aims to investigate the effect of voluntary movements on human temporal perception in multisensory integration. We therefore performed temporal order judgment (TOJ) tasks in audio-tactile integration under three conditions: no movement, involuntary movement, and voluntary movement. It is known that the point of subjective simultaneity (PSS) under the no movement condition, that is, normal TOJ tasks, appears when a tactile stimulus is presented before an auditory stimulus. Our experiment showed that involuntary and voluntary movements shift the PSS to a value that reduces the interval between the presentations of auditory and tactile stimuli. Here, the shift of the PSS under the voluntary movement condition was greater than that under the involuntary movement condition. Remarkably, the PSS under the voluntary movement condition appears when an auditory stimulus slightly precedes a tactile stimulus. In addition, a just noticeable difference (JND) under the voluntary movement condition was smaller than those under the other two conditions. These results reveal that voluntary movements alternate the temporal integration of audio-tactile stimuli. In particular, our results suggest that voluntary movements reverse the temporal perception order of auditory and tactile stimuli and improve the temporal resolution of temporal perception. We discuss the functional mechanism of shifting the PSS under the no movement condition with voluntary movements in audio-tactile integration.

  • Utilizing Global Syntactic Tree Features for Phrase Reordering

    Yeon-Soo LEE  Hyoung-Gyu LEE  Hae-Chang RIM  Young-Sook HWANG  

     
    LETTER-Natural Language Processing

      Vol:
    E97-D No:6
      Page(s):
    1694-1698

    In phrase-based statistical machine translation, long distance reordering problem is one of the most challenging issues when translating syntactically distant language pairs. In this paper, we propose a novel reordering model to solve this problem. In our model, reordering is affected by the overall structures of sentences such as listings, reduplications, and modifications as well as the relationships of adjacent phrases. To this end, we reflect global syntactic contexts including the parts that are not yet translated during the decoding process.

  • Image Quality Assessment Based on Multi-Order Visual Comparison

    Fei ZHOU  Wen SUN  Qingmin LIAO  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E97-D No:5
      Page(s):
    1379-1381

    A new scheme based on multi-order visual comparison is proposed for full-reference image quality assessment. Inspired by the observation that various image derivatives have great but different effects on visual perception, we perform respective comparison on different orders of image derivatives. To obtain an overall image quality score, we adaptively integrate the results of different comparisons via a perception-inspired strategy. Experimental results on public databases demonstrate that the proposed method is more competitive than some state-of-the-art methods, benchmarked against subjective assessment given by human beings.

  • Reconfigurable Out-of-Order System for Fluid Dynamics Computation Using Unstructured Mesh

    Takayuki AKAMINE  Mohamad Sofian ABU TALIP  Yasunori OSANA  Naoyuki FUJITA  Hideharu AMANO  

     
    PAPER-Computer System

      Vol:
    E97-D No:5
      Page(s):
    1225-1234

    Computational fluid dynamics (CFD) is an important tool for designing aircraft components. FaSTAR (Fast Aerodynamics Routines) is one of the most recent CFD packages and has various subroutines. However, its irregular and complicated data structure makes it difficult to execute FaSTAR on parallel machines due to memory access problem. The use of a reconfigurable platform based on field programmable gate arrays (FPGAs) is a promising approach to accelerating memory-bottlenecked applications like FaSTAR. However, even with hardware execution, a large number of pipeline stalls can occur due to read-after-write (RAW) data hazards. Moreover, it is difficult to predict when such stalls will occur because of the unstructured mesh used in FaSTAR. To eliminate this problem, we developed an out-of-order mechanism for permuting the data order so as to prevent RAW hazards. It uses an execution monitor and a wait buffer. The former identifies the state of the computation units, and the latter temporarily stores data to be processed in the computation units. This out-of-order mechanism can be applied to various types of computations with data dependency by changing the number of execution monitors and wait buffers in accordance with the equations used in the target computation. An out-of-order system can be reconfigured by automatic changing of the parameters. Application of the proposed mechanism to five subroutines in FaSTAR showed that its use reduces the number of stalls to less than 1% compared to without the mechanism. In-order execution was speeded up 2.6-fold and software execution was speeded up 2.9-fold using an Intel Core 2 Duo processor with a reasonable amount of overhead.

  • On the Complexity of Computing Discrete Logarithms over Algebraic Tori

    Shuji ISOBE  Eisuke KOIZUMI  Yuji NISHIGAKI  Hiroki SHIZUYA  

     
    PAPER-Fundamentals of Information Systems

      Vol:
    E97-D No:3
      Page(s):
    442-447

    This paper studies the complexity of computing discrete logarithms over algebraic tori. We show that the order certified version of the discrete logarithm problem over general finite fields (OCDL, in symbols) reduces to the discrete logarithm problem over algebraic tori (TDL, in symbols) with respect to the polynomial-time Turing reducibility. This reduction means that if the prime factorization can be computed in polynomial time, then TDL is equivalent to the discrete logarithm problem over general finite fields with respect to the Turing reducibility.

  • The Impact of Opportunistic User Scheduling on Outage Probability of CR-MIMO Systems

    Donghun LEE  Byung Jang JEONG  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E97-B No:3
      Page(s):
    686-690

    In this paper, we study the impact of opportunistic user scheduling on the outage probability of cognitive radio (CR) multiple-input multiple-output (MIMO) systems in the high power region where the peak transmit power constraint is higher than the peak interference constraint. The primary contributions of this paper are the derivation of exact closed-form expressions of the proposed scheduled CR-MIMO systems for outage probability and asymptotic analysis to quantify the diversity order and signal to noise ratio (SNR) gain. Through exact analytical results, we provide the achievable outage probability of the proposed scheduled systems as a function of SNR. Also, through asymptotic analysis, we show that the scheduled CR-MIMO systems provide some diversity order gain over the non-scheduled CR-MIMO systems which comes from multi-user diversity (MUD). Also, the SNR gain of the proposed scheduled systems is identical to that of the non-scheduled CR-MIMO systems.

  • Vanishing Point-Based Road Detection for General Road Images

    Trung Hieu BUI  Takeshi SAITOH  Eitaku NOBUYAMA  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E97-D No:3
      Page(s):
    618-621

    This paper proposes a vanishing point-based road detection method. Firstly, a vanishing point is detected using a texture-based method proposed in a recent study. After that, a histogram is generated for detecting two road borders. The road area is defined as the region between the two road borders and below the vanishing point. The experimental results demonstrate that our method performs well in general road images.

  • Second-Order Perturbative Analysis with Approximated Integration for Propagation Mode in Two-Dimensional Two-Slab Waveguides

    Naofumi KITSUNEZAKI  

     
    PAPER-Optical Waveguide Analysis

      Vol:
    E97-C No:1
      Page(s):
    11-16

    We calculated propagation constants of supermodes for two-dimensional two-slab waveguides, with small core gap, using second-order perturbation expansion from gapless slab waveguide system, and compared our results with the existing works. In the perturbation calculation, we used trapezoidal method to calculate the integral over the transverse direction in space and obtained second-order expansion of (core gap)/(core width) for propagation constants. Our result can explain the qualitative relationship between the propagation constants and the gap distance in the neighbor of (core gap)/(core width) being zero.

  • An Efficient Algorithm for Weighted Sum-Rate Maximization in Multicell OFDMA Downlink

    Mirza Golam KIBRIA  Hidekazu MURATA  Susumu YOSHIDA  

     
    PAPER-Resource Allocation

      Vol:
    E97-A No:1
      Page(s):
    69-77

    This paper considers coordinated linear precoding for rate optimization in downlink multicell, multiuser orthogonal frequency-division multiple access networks. We focus on two different design criteria. In the first, the weighted sum-rate is maximized under transmit power constraints per base station. In the second, we minimize the total transmit power satisfying the signal-to-interference-plus-noise-ratio constraints of the subcarriers per cell. Both problems are solved using standard conic optimization packages. A less complex, fast, and provably convergent algorithm that maximizes the weighted sum-rate with per-cell transmit power constraints is formulated. We approximate the non-convex weighted sum-rate maximization (WSRM) problem with a solvable convex form by means of a sequential parametric convex approximation approach. The second-order cone formulations of an objective function and the constraints of the optimization problem are derived through a proper change of variables, first-order linear approximation, and hyperbolic constraints transformation. This algorithm converges to the suboptimal solution while taking fewer iterations in comparison to other known iterative WSRM algorithms. Numerical results are presented to demonstrate the effectiveness and superiority of the proposed algorithm.

  • A Property for Full CLEFIA-128 Detected by a Middletext Distinguisher under the Known-Key Setting

    Kazumaro AOKI  

     
    LETTER

      Vol:
    E97-A No:1
      Page(s):
    292-297

    CLEFIA is a 128-bit block cipher proposed by Shirai et al. at FSE 2007, and it was selected as several standards. CLEFIA adopts a generalized Feistel structure with the switching diffusion mechanism, which realizes a compact hardware implementation for CLEFIA, and it seems one of the promising candidates to be used for restricted environments, which require that a cryptographic primitive is versatile. It means that we need to evaluate the security of CLEFIA even for unusual scenario such as known-key scenario. As Knudsen and Rijmen did for 7-round AES at Asiacrypt 2007, we construct 17-round known-key distinguisher using two integral characteristics. To combine the 17-round known-key distinguisher with the standard subkey recovery technique for a secret-key scenario, we can construct a known-key distinguisher for full CLEFIA-128 from a random permutation under the framework of middletext distinguisher proposed by Minier et al. at Africacrypt 2009. The known-key distinguisher requires query of 2112 texts, time complexity of 2112, and memory complexity of 23 blocks, with the advantage of e-1, where e is the base of the natural logarithm. Note that there is no practical impact on the security of CLEFIA-128 for the current usages, since the result can only work under the known-key setting and data used by the adversary are enormous and needs a special form.

101-120hit(489hit)