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27461-27480hit(30728hit)

  • ASYL-SdF: A Synthesis Tool for Dependability in Controllers

    Raphael ROCHET  Regis LEVEUGLE  Gabriele SAUCIER  

     
    PAPER-High-Level Synthesis

      Vol:
    E79-D No:10
      Page(s):
    1382-1388

    Synthesis tools are now extensively used in the VLSI circuit design process. They allow a much higher design productivity, but the designer often does not directly control the circuit structure. Thus, when circuits are dedicated to dependable applications, designers have difficulties in implementing manually the devices needed to obtain fault detection or tolerance capabilities. The ASYL-SdF System has been developed over the last few years in order to avoid this break in the design flow, and to facilitate the designer's work when dependability is targeted. This paper gives an overview of the resulting tool, its synthesis flow for fault detection and fault tolerance in Finite State Machines, its limitations and the current developments. Actual circuit implementation results are given in terms of area overheads, expected reliability and experimental fault detection coverage.

  • On Attractive Force of Evanescent Electromagnetic Field on Dielectric Slab*

    Jingbo LI  Masahiro AGU  

     
    PAPER

      Vol:
    E79-C No:10
      Page(s):
    1308-1311

    The electromagnetic force of evanescent field acting on dielectric slab is studied with the use of Maxwell stress tensor. The results show that dielectrics slab may receive always an attractive force when the incident wave is evanescent field while a pressure or an attractive force when the wave is propagating one. The magnitude of the attractive force by evanescent field is much larger than that of the propagating wave. And here some numerical examples are given.

  • Spectral Features due to Dipole-Dipole Interactions in Optical Harmonic Generation

    Hideaki MATSUEDA  Shozo TAKENO  

     
    PAPER-Control and Optics

      Vol:
    E79-A No:10
      Page(s):
    1707-1712

    The dipole-dipole interaction in the quantum mechanical treatment of the matter-radiation dynamics, is shown to give rise to split energy levels reminiscent of the nonlinear coupled spectral features as well as a self-sustained coherent modes. Wiener's theory of nonlinear random processes is applied to the second harmonic generation (SHG), leading also to coupled spectral pulling and dipping features, due to the dual noise sources in the fundamental and the harmonic polarizations. Furthermore, the nonlinear spectral features are suggested to be applied to implement quantum (qubit) gates for computation.

  • Linear Complexity of Periodic Sequences Obtained from GF(q) Sequences with Period qn-1 by One-Symbol Insertion

    Satoshi UEHARA  Kyoki IMAMURA  

     
    LETTER-Information Theory and Coding Theory

      Vol:
    E79-A No:10
      Page(s):
    1739-1740

    From a GF(q) sequence {ai}i0 with period qn - 1 we can obtain new periodic sequences {ai}i0 with period qn by inserting one symbol b GF(q) at the end of each period. Let b0 = Σqn-2 i=0 ai. It Is first shown that the linear complexity of {ai}i0, denoted as LC({ai}) satisfies LC({ai}) = qn if b -b0 and LC({ai}) qn - 1 if b = -b0 Most of known sequences are shown to satisfy the zero sum property, i.e., b0 = 0. For such sequences satisfying b0 = 0 it is shown that qn - LC({ai}) LC({ai}) qn - 1 if b = 0.

  • Application of Blind Source Separation Techniques to Multi-Tag Contactless Identification Systems

    Yannick DEVILLE  Laurence ANDRY  

     
    PAPER-Sequence, Time Series and Applications

      Vol:
    E79-A No:10
      Page(s):
    1694-1699

    Electronic systems are progressively replacing mechanical devices or human operation for identifying people or objects in everyday-life applications. Especially, the contactless identification systems available today have several advantages, but they cannot handle easily several simultaneously present items. This paper describes a solution to this problem, based on blind source separation techniques. The effectiveness of this approach is experimentally demonstrated, especially by using a real-time DSP-based implementation of the proposed system.

  • General Frame Multiresolution Analysis and Its Wavelet Frame Representation

    Mang Ll  Hidemitsu OGAWA  Yukihiko YAMASHITA  

     
    PAPER-Digital Signal Processing

      Vol:
    E79-A No:10
      Page(s):
    1713-1721

    We propose a theory of general frame multiresolution analysis (GFMRA) which generalizes both the theory of multiresolution analysis based on an affine orthonormal basis and the theory of frame multiresolution analysis based on an affine frame to a general frame. We also discuss the problem of perfectly representing a function by using a wavelet frame which is not limited to being of affine type. We call it a "generalized affine wavelet frame." We then characterize the GFMRA and provide the necessary and sufficient conditions for the existence of a generalized affine wavelet frame.

  • A Theorem on an Ω-Matrix Which is a Generalization of the P-Matrix

    Tetsuo NISHI  

     
    PAPER-Nonlinear Circuits and Bifurcation

      Vol:
    E79-A No:10
      Page(s):
    1522-1529

    The author once defined the Ω-matrix and showed that it played an important role for estimating the number of solutions of a resistive circuit containing active elements such as CCCS's. The Ω-matlix is a generalization of the wellknown P-matrix. This paper gives the necessary and sufficient conditions for the Ω-matrix.

  • Advances in Very Low Bit Rate Video Coding in North America

    Thomas S. HUANG  James W. STROMING  Yi KANG  Ricardo LOPEZ  

     
    INVITED PAPER

      Vol:
    E79-B No:10
      Page(s):
    1425-1433

    Research in very low-bit rate coding has made significant advancements in the past few years. Most recently, the introduction of the MPEG-4 proposal has motivated a wide variety of a approaches aimed at achieving a new level of video compression. In this paper we review progress in VLBV categorized into 3 main areas. (1) Waveform coding, (2) 2D Content-based coding, and (3) Model-based coding. Where appropriate we also described proposals to the MPEG-4 committee in each of these areas.

  • Two Variational Principles in Geometrical Optics-Comparisons-

    Masahiro HASHIMOTO  

     
    PAPER

      Vol:
    E79-C No:10
      Page(s):
    1312-1320

    The two variational principles, the Maupertuis' and the Hamilton's principle, are discussed in conjunction with the Fermat's principle. These two principles are shown to describe two different aspects of waves, thus resulting in the different geometry of wave propagation, the treatment of which is thus called the stationary optics or the dynamical optics, respectively. Comparisons for the results obtained from these geometrical optics are given. Another new variational principle valid for the dynamical waves reflected/refracted at the inter-faces, which has not yet been discovered so far, is also derived.

  • Recent Advances in Multiple Scattering Theories and Applications

    Akira ISHIMARU  Yasuo KUGA  

     
    INVITED PAPER

      Vol:
    E79-C No:10
      Page(s):
    1295-1299

    There has been an increasing interest in multiple scattering phenomena in recent years. This is primarily due to the discovery of new multiple scattering phenomena and an increasing awareness that a common thread underlies the work of many researchers in such diverse fields as atmospheric optics, ocean acoustics, radio physics, astrophysics, condensed matter physics, plasma physics, geophysics, bioengineering, etc. In addition, waves in random media is one of the most challenging problems to theoreticians. Thus the field of wave propagation and scattering encompasses the most practical as well as the most theoretical questions. The strong interest in this subject is reflected in the launch of a new journal, Waves in Random Media, by the Institute of Physics, United Kingdom in 1991. This paper reviews some of the most recent developments and discoveries in the field of wave propagation and scattering in turbulence and volume and surface scattering. Included are new discoveries of backscattering enhancement and memory effects which may be applicable to tissue optics, ultrasound imaging, ocean acoustics and geophysical remote sensing. Also indicated are recent developments of numerical Monte-Carlo techniques and experimental studies on this subject.

  • Window-Based Methods for Parameter Estimation of Markov Random Field Images

    Ken-Chung HO  Bin-Chang CHIEU  

     
    PAPER-Image Processing,Computer Graphics and Pattern Recognition

      Vol:
    E79-D No:10
      Page(s):
    1462-1476

    The estimation of model parameter is essentially important for an MRF image model to work well. Because the maximum likelihood estimate (MLE), which is statistically optimal, is too difficult to implement, the conventional estimates such as the maximum pseudo-likelihood estimate (MPLE), the coding method estimate (CME), and the least-squares estimate (LSE) are all based on the (conditional) pixel probabilities for simplicity. However, the conventional pixel-based estimators are not very satisfactorily accurate, especially when the interactions of pixels are strong. We therefore propose two window-based estimators to improve the estimation accuracy: the adjoining-conditional-window (ACW) scheme and the separated-conditional-window (SCW) scheme. The replacement of the pixel probabilities by the joint probabilities of window pixels was inspired by the fact that the pixels in an image present information in a joint way and hence the more pixels we deal with the joint probabilities of, the more accurate the estimate should be. The window-based estimators include the pixel-based ones as special cases. We present respectively the relationship between the MLE and each of the two window-based estimates. Through the relationships we provide a unified view that the conventional pixel-based estimates and our window-based estimates all approximate the MLE. The accuracy of all the estimates can be described by two types of superiority: the cross-scheme superiority that an ACW estimate is more accurate than the SCW estimate with the same window size, and the in-scheme superiority that an ACW (or SCW) estimate more accurate than another ACW (or SCW) estimate which uses smaller window size. The experimental results showed the two types of superiority and particularly the significant improvement in estimation accuracy due to using window probabilities instead of pixel probabilities.

  • New Time-Domain Stability Criterion for Fuzzy Control Systems

    Xihong WANG  Tadashi MATSUMOTO  

     
    PAPER-Control and Optics

      Vol:
    E79-A No:10
      Page(s):
    1700-1706

    In this paper, an extention for Haddad's method, which is the time-domain stability analysis on scalar nonlinear control systems, to multi-variable nonlinear control systems are proposed, and it is shown that these results are useful for the stability analysis of nonlinear control systems with various types of fuzzy controllers.

  • A Power-Combining system of Four Oscillators Using an Eight-Port Hybrid

    Isao OHTA  Tadashi KAWAI  Yoshihiro KOKUBO  

     
    PAPER-Microwave and Millimeter Wave Technology

      Vol:
    E79-C No:10
      Page(s):
    1449-1454

    This paper treats a new-type power combining system of four oscillators equally coupled to one another through an eight-port hybrid. This system is marked by easy analyzability and adjustability from its symmetrical construction. In addition, a combined power from the four oscillators is distinguishably delivered to an arbitrary port of four output ports, and hence can be switched in four ways. Experimental corroboration is presented also.

  • Scattering of Electromagnetic Waves by an Axially Slotted Conducting Elliptic Cylinder in Homogeneous Medium

    Takashi HINATA  Hiroyuki HOSONO  Hidenao ONO  

     
    PAPER

      Vol:
    E79-C No:10
      Page(s):
    1364-1370

    The scattering problem of a plane wave by an axially slotted conducting elliptic cylinder in homogeneous medium is investigated. We present an accurate analysis using the modified point matching method, which can reduce the order of the simultaneous equations to be solved at least by a half under the condition of the same accuracy as compared with an usual point matching method. The accuracy of our results is checked by evaluating the relative errors. Numerical results are given for scattered field patterns by a conducting elliptic cylinder with a slot aperture of angle width 120 when the angle of incidence θinO.

  • Numerical Analysis of 3-D Scattering Problems Using the Yasuura Method

    Mitsunori KAWANO  Hiroyoshi IKUNO  Masahiko NISHIMOTO  

     
    PAPER

      Vol:
    E79-C No:10
      Page(s):
    1358-1363

    The Yasuura method is effective for calculating scattering problems by bodies of revolution. However dealing with 3-D scattering problems, we need to solve bigger size dense matrix equations. One of the methods to solve 3-D scattering is to use multipole expansion which accelerate the convergence rate of solutions on the Yasuura method. We introduce arrays of multipoles and obtain rapidly converging solutions. Therefore we can calculate scattering properties over a relatively wide frequency range and clarify scattering properties such as frequency dependence, shape dependence, and polarization dependence of 3-D scattering from perfectly conducting scatterer. In these numerical results, we keep at least 2 significant figures.

  • A Neural Network for the DOA of VLF/ELF Radio Waves

    Mehrez HIRARI  Masashi HAYAKAWA  

     
    PAPER-Antennas and Propagation

      Vol:
    E79-B No:10
      Page(s):
    1598-1605

    In the present communication we propose the application of unsupervised Artificial Neural Networks (ANN) to solve general ill-posed problems and particularly we apply them to the the estimation of the direction of arrival (DOA) of VLF/ELF radio waves. We use the wave distribution method which consists in the reconstruction of the energy distribution of magnetospheric VLF/ELF waves at the ionospheric base from observations of the wave's electromagnetic field on the ground. The present application is similar to a number of computerized tomography and image enhancement problems and the proposed algorithm can be straightforwardly extended to other applications in which observations are linearly related to unknowns. Then, we have proven the applicability and also we indicate the superiority of the ANN to the conventional methods to handle this kind of problems.

  • A Partial Scan Design Approach based on Register-Transfer Level Testability Analysis

    Akira MOTOHARA  Sadami TAKEOKA  Mitsuyasu OHTA  Michiaki MURAOKA  

     
    PAPER-Design for Testability

      Vol:
    E79-D No:10
      Page(s):
    1436-1442

    An approach to design for testability using register-transfer level (RTL) partial scan selection is described. We define an RTL circuit model which enables efficient description in an electronic system design automation (ESDA) tool and testability analysis which leads to effective partial scan selection for RTL design including data path circuits and control circuits such as state machines. We also introduced a method of partial scan selection at RTL which selects critical registers and state machines based on RTL testability analysis. DFT techniques using gate level testability measures have been studied and concluded that they are not successful in achieving high fault coverage [15]. However, we started this work for the following reasons, 1) In sequential ATPG procedure, more than two memory elements belonging to a functional units such as registers and state machines are often required to be justified at a time. At RTL, state machines and registers are explicitly described and recognized as functional units while gate level memory elements are scattered over the circuit. 2) As discussed in [6], if the circuit is modified so that the test sequence which causes state transition between initial and final states of sequential ATPG can be easily obtained, ATPG results can be also improved. Complex state machines can be identified at RTL. According to the experimental results, our gate level DFT achieves high fault coverage comparable with the previously published most successful DFT methods, and DFT at RTL resulted in higher fault coverage than gate level DFT at much shorter CPU time.

  • Motion-Compensated Prediction Method Based on Perspective transform for Coding of Moving Images

    Atsushi KOIKE  Satoshi KATSUNO  Yoshinori HATORI  

     
    PAPER

      Vol:
    E79-B No:10
      Page(s):
    1443-1451

    Hybrid image coding method is one of the most promising methods for efficient coding of moving images. The method makes use of jointly motion-compensated prediction and orthogonal transform like DCT. This type of coding scheme was adopted in several world standards such as H.261 and MPEG in ITU-T and ISO as a basic framework [1], [2]. Most of the work done in motion-compensated prediction has been based on a block matching method. However, when input moving images include complicated motion like rotation or enlargement, it often causes block distortion in decoded images, especially in the case of very low bit-rate image coding. Recently, as one way of solving this problem, some motion-compensated prediction methods based on an affine transform or bilinear transform were developed [3]-[8]. These methods, however, cannot always express the appearance of the motion in the image plane, which is projected plane form 3-D space to a 2-D plane, since the perspective transform is usually assumed. Also, a motion-compensation method using a perspective transform was discussed in Ref, [6]. Since the motion detection method is defined as an extension of the block matching method, it can not always detect motion parameters accurately when compared to gradient-based motion detection. In this paper, we propose a new motion-compensated prediction method for coding of moving images, especially for very low bit-rate image coding such as less than 64 kbit/s. The proposed method is based on a perspective transform and the constraint principle for the temporal and spatial gradients of pixel value, and complicated motion in the image plane including rotation and enlargement based on camera zooming can also be detected theoretically in addition to translational motion. A computer simulation was performed using moving test images, and the resulting predicted images were compared with conventional methods such as the block matching method using the criteria of SNR and entropy. The results showed that SNR and entropy of the proposed method are better than those of conventional methods. Also, the proposed method was applied to very low bit-rate image coding at 16 kbit/s, and was compared with a conventional method, H.261. The resulting SNR and decoded images in the proposed method were better than those of H.261. We conclude that the proposed method is effective as a motion-compensated prediction method.

  • Linear Predictive Transmission Diversity for TDMA/TDD Personal Communication Systems

    Yasushi KONDO  Keisuke SUWA  

     
    PAPER-Mobile Communication

      Vol:
    E79-B No:10
      Page(s):
    1586-1591

    This paper proposes linear predictive transmission diversity for TDMA/TDD personal communication systems and evaluates the effects of fading correlation and unequal average signal power Rayleigh fading on these system. The average bit error rate (BER) performance is calculated by computer simulation and the BER of zero order prediction is theoretically analyzed. The performance degradation caused by the error from prediction, fading correlation, and unequal average signal power is found to be almost independent of each other.

  • Reconstruction of Two Dimensional Rough Surface with Gaussian Beam Illumination

    Kazunori HARADA  Akira NOGUCHI  

     
    PAPER

      Vol:
    E79-C No:10
      Page(s):
    1345-1349

    A method is presented for reconstructing the surface profile of a two dimensional rough surface boundary from the scattered far field data. The proposed inversion algorithm is based on the Kirchhoff approximation and in order to determine the surface profile, the numerical results illustrating the method are presented.

27461-27480hit(30728hit)