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4361-4380hit(4570hit)

  • On the Relationship between Discrete Walsh Transform and the Adaptive LMS Algorithm

    Jiangtao XI  Joe F. CHICHARO  

     
    LETTER-Adaptive Signal Processing

      Vol:
    E77-A No:7
      Page(s):
    1199-1201

    An adaptive LMS filtering system is proposed for computing the Discrete Walsh Transform (DWT). The signal to be transformed serves as the 'desired signal' for the adaptive filter, while a set of periodic Walsh sequences serve as the input signal vector for the adaptive filter. The weights of the adaptive filter provide the DWT. The given approach is more efficient in terms of the required computations and memory locations compared with the direct approach. In contract with existing Fast DWT algorithm, the proposed solution provides more flexibility as far as the signal block length is concerned. In other words, the proposed approach is not restricted to a block length N to be of power 2.

  • Knowledge for Understanding Table-Form Documents

    Toyohide WATANABE  Qin LUO  Noboru SUGIE  

     
    PAPER

      Vol:
    E77-D No:7
      Page(s):
    761-769

    The issue about document structure recognition and document understanding is today one of interesting subjects from a viewpoint of practical applications. The research objective is to extract the meaningful data from document images interpretatively and also classify them as the predefined item data automatically. In comparison with the traditional image-processing-based approaches, the knowledge-based approaches, which make use of various knowledge in order to interpret structural/constructive features of documents, have been currently investigated as more flexible and applicable methods. In this paper, we propose a totally integrated paradigm for understanding table-form documents from a viewpoint of the architectural framework.

  • Wiener-Hopf Analysis of the Diffraction by a Parallel-Plate Waveguide Cavity with Partial Material Loading

    Shoichi KOSHIKAWA  Kazuya KOBAYASHI  

     
    PAPER-Microwave and Millimeter Wave Technology

      Vol:
    E77-C No:6
      Page(s):
    975-985

    The plane wave diffraction by a two-dimensional parallel-plate waveguide cavity with partial material loading is rigorously analyzed for both the E and the H polarization using the Wiener-Hopf technique. Introducing the Fourier transform for the scattered field and applying boundary conditions in the transform domain, the problem is formulated in terms of the simultaneous Wiener-Hopf equations satisfied by the unknown spectral functions. The Wiener-Hopf equations are solved exactly via the factorization and decomposition procedure leading to the formal solution, which involves branch-cut integrals with unknown integrands as well as infinite series with unknown coefficients. Applying rigorous asymptotics with the aid of the edge condition, the approximate solution to the Wiener-Hopf equations is derived in the form suitable for numerical computations. The scattered field inside and outside the cavity is evaluated by taking the inverse Fourier transform together with the use of the saddle point method. Numerical examples of the radar cross section are presented for various physical parameters, and the far field backscattering characteristics of the cavity are discussed in detail. Some comparisons with a high-frequency technique are also given to validate the present method.

  • Parametric Rotary Speed Sensor of Robust Motor Control

    Emenike C. EJIOGU  Kazuhiko ONO  Yorimoto TANNO  

     
    LETTER-Instrumentation and Control

      Vol:
    E77-C No:6
      Page(s):
    1012-1017

    If one of the R, L, or C Parameter of an RLC parallel circuit is changed periodically, under certain conditions, an oscillation called Parametric oscillation occurs. If one of remaining circuit elements is made to change due to an external cause (e.g. an external electric or magnetic field), then the parametric oscillation will experience some modulation. This modulation process and the subsequent demodulation can be exploited to create several types of sensors. In this letter, we describe the features of a new parametric magnetic speed sensor and its application in Induction motor robust control.

  • A Noninvasive Method for Dielectric Property Measurement of Biological Tissues

    Jianqing WANG  Tasuku TAKAGI  

     
    PAPER

      Vol:
    E77-B No:6
      Page(s):
    738-742

    A noninvasive method for measuring complex permittivity of biological tissues is proposed. The noninvasive method is based on an inverse scattering technique which employs an iterative procedure. The iterative procedure consists of solving an electric field integral equation using the method of moments and minimizing the square difference between calculated and measured scattered fields. Implementation of the noninvasive method requires the knowledge of the target shape, the incident and measured scattered fields. Based on the noninvasive method, a measuring system of complex permittivity is developed and its reliability is verified.

  • Effect of 2.45GHz Microwave Irradiation on Monkey Eyes

    Yoshitsugu KAMIMURA  Ken-ichi SAITO  Toshikazu SAIGA  Yoshifumi AMEMIYA  

     
    LETTER

      Vol:
    E77-B No:6
      Page(s):
    762-765

    In 1985, Kues et al. (Bioelectromagnetics, 6, pp.177-188, 1985) reported that corneal endothelial abnormalities were observed after a 4-hour exposure of anesthetized monkey eyes to 2.45GHz CW. We have traced their experimental study without anesthetization. Although we irradiated with power density exceeding the threshold of 30mW/cm2 obtained by them, we could not observe the same abnormalities as they did.

  • An Improved Adaptive Notch Filter for Detection of Multiple Sinusoids

    Shotaro NISHIMURA  

     
    PAPER-Digital Signal Processing

      Vol:
    E77-A No:6
      Page(s):
    950-955

    In this paper, a new structure which is useful for the detection of multiple sinusoids is presented. The proposed structure is based on the direct form second-order IIR notch filter using simplified adaptive algorithm. It has been shown that the convergence characteristics of the proposed structure are much improved compared with the previously proposed structure. A cascaded adaptive notch filter using the proposed second-order section is also shown. It takes multiple sinusoids corrupted by white Gaussian noise and produces the individual sinusoids at each of the outputs. The results of computer simulation are shown which confirm the theoretical prediction.

  • Transmission Characteristics of CPW Bends for Various Curvatures

    Hiroyuki SAWASA  Hideki NAKANO  Kohji KOSHIJI  Eimei SHU  

     
    LETTER

      Vol:
    E77-C No:6
      Page(s):
    949-951

    Transmission characteristics of CPW bends having various curvatures and a fixed bend angle were measured. It was found that the transmission level shows dips at some particular frequencies, and that the dips are less pronounced as the radius of curvature becomes larger.

  • Organic Display Devices Using Poly (Arylene Vinylene) Conducting Polymers

    Mitsuyoshi ONODA  Hiroshi NAKAYAMA  Yutaka OHMORI  Katsumi YOSHINO  

     
    PAPER

      Vol:
    E77-C No:5
      Page(s):
    672-678

    Optical recording has been performed successfully by the preirradiation of light upon the precursor of poly (arylene vinylene) conducting polymers such as poly (p-phenylene vinylene) (PPV) and poly (1,4-naphthalene vinylene) (PNV) and subsequent thermal treatment. The effect has been tentatively interpreted in terms of the deterioration of the irradiated area of the precursor polymer in which polymerization is suppressed. Furthermore, an orange electroluminescent (EL) diode utilizing PNV has been demonstrated for the first time and the EL properties of PNV are discussed in comparison with those of EL diode utilizing PPV. The EL emission of these two devices are discussed in terms of radiative recombination of the singlet polaron exciton formed by the injection of electrons and holes, the difference of effective conjugation length and the interchain transfer of polaron excitons.

  • Parallel Implementations of Back Propagation Networks on a Dynamic Data-Driven Multiprocessor

    Ali M. ALHAJ  Hiroaki TERADA  

     
    PAPER-Computer Systems

      Vol:
    E77-D No:5
      Page(s):
    579-588

    The data-driven model of computation is well suited for flexible and highly parallel simulation of neural networks. First, the operational semantics of data-driven languages preserve the locality and functionality of neural networks, and naturally describe their inherent parallelism. Second, the asynchronous data-driven execution facilitates the implementation of large and scalable multiprocessor systems, which are necessary to obtain considerable degrees of simulation sppedups. In this paper, we present a dynamic data-driven multiprocessor system, and demonstrate its suitability for the paralel simulation of back propagation neural networks. Two parallel implementations are described and evaluated using an image data compression network. The system is scalable, and as a result, the performance improved proportionally with the increase in number of processors.

  • Inelastic Electron Tunneling Spectroscopy and Optical Characterization of TMPD Adsorbed Cn TCNQ Labgmuir-Blodgett Films

    Shigekazu KUNIYOSHI  Masataka NAGAOKA  Kazuhiro KUDO  Shin-ichi TERASHITA  Yukihiro OZAKI  Keiji IRIYAMA  Kuniaki TANAKA  

     
    PAPER

      Vol:
    E77-C No:5
      Page(s):
    657-661

    To investigate the effect of alkyl chain length and adsorption time on the charge-transfer complex formation, ultraviolet-visible absorption and inelastic electron tunneling (IET) spectroscopy measurements were carried out for the tetramethylphenylenediamine (TMPD; donor molecule) adsorbed dodecyl-, pentadecyl- and octadecyl-tetracyanoquinodimethane (TCNQ) Langmuir-Blodgett (LB) films. In the optical absorption spectra, the main peak of LB films shows a red-shift depending on alkyl chain length and adsorption time. Furthermore, the dependence on alkyl chain length and adsorption time are also shown in the IET spectra. These results demonstrate that adsorption LB methods enable to control the adsorption ratio of functional molecules and the CT complex formation.

  • Shared Pseudo-Random Secret Generation Protocols

    Manuel CERECEDO  Tsutomu MATSUMOTO  Hideki IMAI  

     
    PAPER

      Vol:
    E77-A No:4
      Page(s):
    636-645

    An extension of the notion of cryptographically strong pseudo-random generator to a distributed setting is proposed in this paper. Instead of a deterministic function to generate a pseudo-random bit string from a truly random shorter string, we have a deterministic secure protocol for a group of separate entities to compute a secretly shared pseudo-random string from a secretly shared and truly random shorter string. We propose a precise definition of this notion in terms of Yao's computational entropy and describe a concrete construction using Shamir's pseudo-random number generator. Several practical applications are also discussed.

  • Estimation of Arm Posture in 3D-Space from Surface EMG Signals Using a Neural Network Model

    Yasuharu KOIKE  Mitsuo KAWATO  

     
    INVITED PAPER

      Vol:
    E77-D No:4
      Page(s):
    368-375

    We have aimed at constructing a forward dynamics model (FDM) of the human arm in the form of an artificial neural network while recordings of EMG and movement trajectories. We succeeded in: (1) estimating the joint torques under isometric conditions and (2) estimating trajectories from surface EMG signals in the horizontal plane. The human arm has seven degrees of freedom: the shoulder has three, the elbow has one and the wrist has three. Only two degrees of freedom were considered in the previous work. Moreover, the arm was supported horizontally. So, free movement in 3D space is still a necessity. And for 3D movements or posture control, compensation for gravity has to be considered. In this papre, four joint angles, one at the elbow and three at the shoulder were estimated from surface EMG signals of 12 flexor and extensor muscles during posture control in 3D space.

  • On a Unified Synthesizing Approach for Cellular Neural Networks

    Chun-ying HO  Shinsaku MORI  

     
    PAPER-Network Synthesis

      Vol:
    E77-D No:4
      Page(s):
    433-442

    In this paper, we develop a unified synthesizing approach for the cloning templates of Cellular Neural Networks (CNNs). In particular, we shall consider the case when the signal processing problem is complex, and a multilayered CNN with time-variant templates is necessary. The method originates from the existence of correspondence between the cloning templates of Cellular Neural Network and its discrete counterpart, Discrete-Time Cellular Neural Network (DTCNN), in solving a prescribed image processing problem when time-variant templates are involved. Thus, one can start with calculating the cloning templates from DTCNN, and then translating the cloning templates to those for CNN operations. As a result, the mathematical tools being used in the synthesis of Discrete-time Cellular Neural Network can also be applied to the analog type Cellular Neural Network. This inevitably helps to simplify the design problem of CNN for signal processing. Examples akin to contour drawing and parallel thinning are shown to illustrate the merits of our proposed method.

  • Failure Analysis in Si Device Chips

    Kiyoshi NIKAWA  

     
    INVITED PAPER

      Vol:
    E77-C No:4
      Page(s):
    528-534

    Recent developments and case studies regarding VLSI device chip failure analysis are reviewed. The key failure analysis techniques reviewed include EMMS (emission microscopy), OBIC (optical beam induced current), LCM (liquid crystal method), EBP (electron beam probing), and FIB (focused ion beam method). Further, future possibilities in failure analysis, and some promising new tools are introduced.

  • An Analysis of and a Method of Enhancing the Intensity of OBIRCH Signal for Defects Observation in VLSI Metal Interconnections

    Naoki KAWAMURA  Tomoaki SAKAI  Masakazu SHIMAYA  

     
    PAPER

      Vol:
    E77-C No:4
      Page(s):
    579-584

    The origin of and a method of enhancing the Optical Beam Induced Resistance Change (OBIRCH) signal for defect observation in VLSI metal interconnections is discussed based on a numerical analysis of three-dimensional thermal conduction and experimental results. The numerical analysis shows that the OBIRCH signal originates from a slight increase in the resistance of the metal line caused by laser beam heating and that its effect is influenced by the temperature of the metal layer. Both simulations and experimental results suggest that cooling the sample is preferable to detect the OBIRCH signal. The decrease in the total resistance of the metal line without any change in the amount of the resistance increase under laser illumination is found to be the main cause of the OBIRCH signal enhancement under low temperature measurement.

  • Throughput Analysis of ARQ Schemes in Dialogue Communication over Half-Duplex Line

    Chun-Xiang CHEN  Masaharu KOMATSU  Kozo KINOSHITA  

     
    PAPER-Communication Theory

      Vol:
    E77-B No:4
      Page(s):
    485-493

    This paper studies the performance of a dialogue communication system which consists of two stations over a half-duplex line. When a station seizes the right to send its packets, it can consecutively transmits k packets. We analyze the transmission time of a message and the throughput performances of Stop-and-Wait, Go-back-N and Selective-Repeat protocols for the half-duplex line transmission system. Based on the analytical and numerical results, we clarify the influences of the switching and the thinking times, which exist in half-duplex line system, on the throughput performance, and give the optimal k which makes the throughput to become maximum. It is observed that the throughput performances are greatly influenced not only by the switching and thinking times but also by the average message length.

  • Multimedia Communication Protocols and Services for Broadband Private Networks

    Shiro SAKATA  

     
    INVITED PAPER

      Vol:
    E77-B No:3
      Page(s):
    283-293

    There has been growing interest in Broadband ISDN (B-ISDN) based on ATM (Asynchronous Transfer Mode) technologies, since ATM is expected to support a wide range of applications through high-speed and flexible multimedia communication capabilities. This paper reviews and discusses technical issues on multimedia communication protocols and services from the integration points of view of computer and communication technologies. An ISDN-based distributed multimedia and multi-party desktop conference system called MERMAID is introduced as an example which offers highly-sophisticated functions for remote collaborations among multiple users. This system, which was developed in early 1989 and has been used for daily research work since then, involves B-ISDN key technologies related to multimedia and multicast protocols, and computer architecture for groupware applications.

  • Flexible Information Sharing and Handling System--Towards Knowledge Propagation--

    Yoshiaki SEKI  Toshihiko YAMAKAMI  Akihiro SHIMIZU  

     
    PAPER

      Vol:
    E77-B No:3
      Page(s):
    404-410

    The use of computers with private networks has accelerated the electronic storage of business information in office systems. With the rapid progress in processing capability and small sizing of the computer world, private networks are going to be more intelligent. The utilization of shared information is a key issue in modern organizations, in order to increase the productivity of white-collar workers. In the CSCW research field, it is said that informal and unstructured information is important in group work contexts but difficult to locate in a large organization. Many researchers are paying particular attention to the importance of support systems for such information. These kinds of information are called Organizational memory or Group Memory. Our research focuses on knowledge propagation with private networks in the organization. This means emphasis on the process; with which organized information or the ability to use information is circulated throughout the organization. Knowledge propagation has three issues: knowledge transmission, destination locating and source locating. To cope with these issues we developed FISH, which stands for Flexible Information Sharing and Handling system. FISH was designed to provide cooperative information sharing in a group work context and to explore knowledge propagation. FISH stores fragmental information as cards with multiple keywords and content. This paper discusses a three-layered model that describes computer supported knowledge transmission. Based on this model, three issues are discussed regarding knowledge propagation. FISH and its two-year experiment are described and knowledge propagation is explored based on the results of this experiment.

  • Hot Carrier Evaluation of TFT by Emission Microscopy

    Junko KOMORI  Jun-ichi MITSUHASHI  Shigenobu MAEDA  

     
    PAPER-Device Technology

      Vol:
    E77-C No:3
      Page(s):
    367-372

    A new evaluation technique of hot carrier degradation is proposed and applied to practical evaluation of p-channel polycrystalline silicon thin film transistors (TFT). The proposed technique introduces emission microscopy which is particularly effective for evaluating TFT devices. We have developed an automatic measurement system in which measurement of the electrical characteristics and monitoring the photo emission are done simultaneously. Using this system, we have identified the dominant mechanism of hot carrier degradation in TFTs, and evaluated the effect of plasma hydrogenation on hot carrier degradation.

4361-4380hit(4570hit)