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37401-37420hit(42756hit)

  • Macro- and Micro-Tribological Properties of Polished CVD Diamond Films and Trial Processing of Diamond

    Shojiro MIYAKE  Takanori MIYAMOTO  Reizo KANEKO  Toshiyuki MIYAZAKI  

     
    PAPER

      Vol:
    E78-C No:2
      Page(s):
    180-185

    Micro-tribology is a key technology in micro-machine. Atomic-scale wear and friction fluctuations degrade the performance of micro-machines. New wear-resistant, low friction materials should be useful in reducing micro- and macro-tribological wear and friction fluctuations. Our investigation of the frictional characteristics of polished CVD diamond films by FFM (friction force microscope), AFM (atomic force microscope) and conventional reciprocating tribometer and trial micro processing of diamond produced three main results. First, the friction coefficient of diamond film increases rapidly with decreasing load in the micro-load region. This is partially due to the surface tension of adsorbed water on the surface under high humidity. In the macro-load region also, the friction coefficient increases with decreasing load, but, in this case it is due to elastic deformation. The second result is that diamond film has excellent wear resistance in the micro-load region compared with silicon and diamond-like carbon (DLC) film. Finally, a micro-diamond gear and diamond shaft were fabricated by laser machining and thermo-chemical etching, and then assembled.

  • Design and Implementations of a Learning T-Model Neural Network

    Zheng TANG  Okihiko ISHIZUKA  

     
    LETTER-Neural Networks

      Vol:
    E78-A No:2
      Page(s):
    259-263

    In this letter, we demonstrate an experimental CMOS neural circuit towards an understanding of how particular computations can be performed by a T-Model neural network. The architecture and a digital hardware implementation of the learning T-Model network are presented. Our experimental results show that the T-Model allows immense collective network computations and powerful learning.

  • A Rule-Embedded Neural-Network and Its Effectiveness in Pattern Recognition with -Posed Conditions

    Mina MARUYAMA  Nobuo TSUDA  Kiyoshi NAKABAYASHI  

     
    PAPER-Bio-Cybernetics and Neurocomputing

      Vol:
    E78-D No:2
      Page(s):
    152-162

    This paper describes an advanced rule-embedded neural network (RENN+) that has an extended framework for achieving a very tight integration of learning-based neural networks and rule-bases of existing if-then rules. The RENN+ is effective in pattern recognition with ill-posed conditions. It is basically composed of several component RENNs and an output RENN, which are three-layer back-propagation (BP) networks except for the input layer. Each RENN can be pre-organized by embedding the if-then rules through translation of the rules into logic functions in a disjunctive normal form, and can be trainded to acquire adaptive rules as required. A weight-modification-reduced learning algorithm (WMR) capable of standard regularization is used for the post-training to suppress excessive modification of the weights for the embedded rules. To estimate the effectiveness of the proposed RENN+, it was used for pattern recognition in a radar system for detection of buried pipes. This trial showed that a RENN+ with two component RENNs had good recognition capability, whereas a conventional BP network was ineffective.

  • Measurements on Low Frequency Phase and Amplitude Fluctuations and Its Application to Reduce the Noise in Bipolar Transistor Circuits

    Keiji TAKAGI  

     
    LETTER

      Vol:
    E78-B No:2
      Page(s):
    279-280

    A system for measuring the low frequency amplitude and phase noises was set-up, with employing a phase sensitive detector and phase-shifter. It is noted that both noises were partly correlated. The phase noise was explained by the transit time fluctuation due to the fluctuating diffusion coefficient. The amplitude noise reduction was demonstrated by applying the inverted output of the phase noise to the amplitude noise.

  • Evaluation of Antenna Factor of Biconical Antennas for EMC Measurements

    Koichi GYODA  Yukio YAMANAKA  Takashi SHINOZUKA  Akira SUGIURA  

     
    PAPER

      Vol:
    E78-B No:2
      Page(s):
    268-272

    Broadband antennas such as biconical antennas and log-periodic dipole antennas are generally used in automatic EMC measurements. However, these broadband antennas have not been used for accurate measurement because accurate specifications for them are lacking. Therefore, more accurate analysis is urgently required by the CISPR (International Special Committee on Radio Interference), to establish the specifications for broadband antennas for EMC measurements. In this paper, the AF of biconical antennas is calculated by using Moment Methods. The frequency characteristics and antenna height dependency of AF are presented. AF is also measured and compared to the data obtained by the calculations. Good agreement between the calculations and measurements is achieved, indicating the usefulness of our computation method. In addition, the effect of antenna separation distance and transmitting antenna height on AF is investigated. The calculated AF deviation from the reference value is nearly 0dB except for certain antenna arrangements. In these antenna arrangements, the field becomes null at the receiving antenna and widely varies in magnitude and phase around the null points. Therefore, the antenna is immersed in a non-uniform field, while the AF is defined on the assumption of a uniform field. Consequently, the erroneous AF will be derived from measurements around these null points and it will be greatly different from that obtained at other antenna heights. Thus, it is better to avoid these conditions during actual measurements. The effect of the ground plane on AF is also evaluated. AF is shown to be seriously affected by the ground plane especially at frequencies around 90MHz. It should be noted that AF deviation has crests corresponding to the null field at 300MHz. The obtained data will be useful in establishing specifications of biconical antennas for EMC measurements.

  • Off-Line Handwritten Word Recognition with Explicit Character Juncture Modeling

    Wongyu CHO  Jin H. KIM  

     
    PAPER-Image Processing, Computer Graphics and Pattern Recognition

      Vol:
    E78-D No:2
      Page(s):
    143-151

    In this paper, a new off-line handwritten word recognition method based on the explicit modeling of character junctures is presented. A handwritten word is regarded as a sequence of characters and junctures of four types. Hence both characters and junctures are explicitly modeled. A handwriting system employing hidden Markov models as the main statistical framework has been developed based on this scheme. An interconnection network of character and ligature models is constructed to model words of indefinite length. This model can ideally describe any form of hamdwritten words including discretely spaced words, pure cursive words, and unconstrained words of mixed styles. Also presented are efficient encoding and decoding schemes suitable for this model. The system has shown encouraging performance with a standard USPS database.

  • FOREWORD

    Shuichi NITTA  

     
    FOREWORD

      Vol:
    E78-B No:2
      Page(s):
    87-87
  • Design of TCM Signals for Class-A Impulsive Noise Environment

    Shinichi MIYAMOTO  Masaaki KATAYAMA  Norihiko MORINAGA  

     
    PAPER

      Vol:
    E78-B No:2
      Page(s):
    253-259

    In this paper, a design of TCM signals for Middleton's class-A impulsive noise environment is investigated. The error event characteristics under the impulsive noise is investigated, and it is shown that the length of the signal sequence is more important than Euclidean distance between the signal sequences. Following this fact, we introduce the shortest error event path length as a measure of the signal design. In order to make this value large, increasing of states of convolutional codes is employed, and the performance improvement achieved by this method is evaluated. Numerical results show the great improvement of the error performance and conclude that the shortest error event path length is a good measure in the design of TCM signals under impulsive noise environment. Moreover, the capacity of class-A impulsive noise channel is evaluated, and the required signal sets expansion rates to obtain the achievable coding gain is discussed.

  • An Equivalent Transmission Line Model for Electromagnetic Penetration through Reinforced Concrete Walls

    Saverio CRISTINA  Antonio ORLANDI  

     
    PAPER

      Vol:
    E78-B No:2
      Page(s):
    218-229

    In this paper we have considered both frequency-domain and time-domain shielding provided by reinforced concrete walls and floors in planar geometries, against electromagnetic fields due to electromagnetic pulses. The concrete composites have been modeled as isotropic, homogeneous lossy materials and the metal bars of the reinforcement have been modeled as a wire-mesh grid under the assumptions that the wire junctions are connected and that thin-wire approximation applies. The presence of imperfect wire junctions due to oxidation of overlapping or poor welding is taken into account by introducing an equivalent distributed junction impedance. We have used the formalism of the transmission matrix of network theory. Such a formalism is useful in dealing with shielding problems involving bodies with non-separable layers, such as the reinforcement and the concrete. The behavior of a reinforced concrete wall with respect to an incident electromagnetic field is a function both of the low-pass behavior of the concrete, and of the inductive effects of the metal frame impedance. The electric field inside a reinforced concrete structure shows an attenuation, a time delay when it reaches its maximum value, and an increase in its temporal width with respect to the electric field outside. The proposed model is validated by comparison with numerical and measured results.

  • Three-Dimensional Microfabrication of Single-Crystal Silicon by Plasma Etching

    Tomoaki GOTO  Kouji MATSUSHITA  Katsumi HIRONO  

     
    PAPER

      Vol:
    E78-C No:2
      Page(s):
    167-173

    A conventional anode coupled plasma etching process has been developed to etch 300 µm-deep cavities and 600 µm-through holes with nearly vertical sidewalls into single crystal silicon. An optimized SF6/O2 gas mixture results in a nearly vertical etching profile. A silicon wafer was fabricated with a large number of cavities and through holes with less than 1 percent uniformity. It was also experimentally confirmed that this process can be used to etch vertical cavities and through holes in single-crystal silicon with any orientation. This process has the advantage of unlimited etching depth and etching patterns. Advantages in mechanical strength are obtained because a micro-curve is formed at the bottom edge of the cavities. This etching process developed on a conventional plasma etching system was utilized to fabricate a torsional vibrator that consists of single-crystal silicon and Pyrex glass.

  • Estimation of Electromagnetic Interference Field Emitted from Telecommunications Line

    Fujio AMEMIYA  Nobuo KUWABARA  Tsuyoshi IDEGUCHI  

     
    PAPER

      Vol:
    E78-B No:2
      Page(s):
    159-167

    An electric field is created around a telecommunications line by common-mode currents caused by clock signals, switching pulses and digitally transmitted signals. This field is a potential source of interference to radio reception. This paper describes measurement results for interference fields radiated from a telecommunications line. A method using optical fiber was used to measure the relation between common mode voltage and radiated electric field, and the results were compared with the calculated results discussed in IEC/CISPR. Our results show that the limits discussed in the CISPR are effective in restricting the electromagnetic interference due to conducted disturbances at telecommunication ports. The electric field strength from the telecommunications line caused by telecommunications signals is estimated on the basis of the relation between the common mode voltage and the radiated field strength. In this estimation, the dependence on the longitudinal conversion loss (LCL) of the telecommunications line is taken into account. The results show that the telecommunications signal on the ISDN basic access interface is not an interference source provided that the LCL of the telecommunications system meets the requirements for the ISDN interface.

  • Finding All Solutions of Piecewise-Linear Resistive Circuits Containing Nonseparable Transistor Models

    Kiyotaka YAMAMURA  Osamu MATSUMOTO  

     
    LETTER-Numerical Analysis and Self-Validation

      Vol:
    E78-A No:2
      Page(s):
    264-267

    An efficient algorithm is given for finding all solutions of piecewise-linear resistive circuits containing nonseparable transistor models such as the Gummel-Poon model or the Shichman-Hodges model. The proposed algorithm is simple and can be easily programmed using recursive functions.

  • 4-Move Perfect ZKIP for Some Promise Problems

    Kaoru KUROSAWA  Wakaha OGATA  Shigeo TSUJII  

     
    PAPER

      Vol:
    E78-A No:1
      Page(s):
    34-41

    In this paper, we consider ZKIPs for promise problems. A promise problem is a pair of predicates (Q,R). A Turning machine T solves the promise problem (Q,R) if, for every x satisfying Q(x), machine T halts and it answers "yes" iff R(x). When ¬Q (x), we do not care what T does. First, we define "promised BPP" which is a promise problem version of BPP. Then, we prove that a promise problem (Q,R) has a 3-move interactive proof system which is black-box simulation zero knowledge if and only if (Q,R) ∈ promised BPP. Next, we show a "4-move" perfect ZKIPs (black-box simulation) for a promise problem of Quadratic Residuosity and that of Blum Numbers under no cryptographic assumption.

  • Numerical Analysis of an Optical X Coupler with a Nonlinear Dielectric Region

    Hirohisa YOKOTA  Koichi KIMURA  Sadao KURAZONO  

     
    PAPER

      Vol:
    E78-C No:1
      Page(s):
    61-66

    For an application to the optical signal processing devices, we propose the optical X coupler which consists of two bending waveguides and a nonlinear dielectric region. To analyze this structure accurately we utilized the iterative finite difference beam propagation method (iterative FD-BPM). In this paper the formulation of the iterative FD-BPM for one wave and two waves cases are presented, respectively. We investigate following two cases. First, we consider the case that the light is launched into one of the input ports. We calculate the evolutions of the field amplitude and the transmission characteristics for the input power. Second, we consider the case that the signal light with the constant power is launched into one of the input ports and that the control light with the wavelength different from that of the signal light is launched into another input port. We calculate the evolutions of the field amplitude and the transmission characteristics of the signal light for the power of control light. As a result of the analysis, we show that all-optical switching operation is possible in the proposed structure.

  • A New Class of Non-interactive ID-Based Key Sharing Schemes and Its Performances

    Ryuichi SAKAI  Masao KASAHARA  

     
    PAPER

      Vol:
    E78-A No:1
      Page(s):
    51-58

    In this paper, we propose a new class of ID-based non-interactive key sharing scheme with a trusted center which generate a common key on the basis of a linear combination of the center secrets. We also discuss the security of the proposed schemes, and show that the proposed schemes prevent the conventional collusion attack, by adding another random integers unique to each user, on the secret vector that is assigned to the user. Furthermore, we present a new type of a statistical collusion attack which is more suitable for the proposed schemes. We also present the lower bound of the threshold of the statistical collusion attack on the proposed schemes. The proposed schemes can be easily implemented compared with other schemes as they require only computing of the inner product of two vectors over finite ring (including finite field) and an Euclidean quotient, for generating the common key. Our proposed schemes can be regarded as modified versions of the Blom's original scheme. However our proposed schemes are secure against our new type of the attack, as well as the collusion attack based on the solving of the linear equations, although Blom's scheme is insecure against both of these collusion attacks.

  • On the Negation-Limited Circuit Complexity of Clique Functions

    Tetsuro NISHINO  Keisuke TANAKA  

     
    LETTER-Algorithm and Computational Complexity

      Vol:
    E78-D No:1
      Page(s):
    86-89

    A negation-limited circuit is a combinational circuit which includes at most [log(n1)] NOT gates. We show a relationship between the size of negation-limited circuits computing clique functions and the number of NOT gates in the circuits.

  • Band Operation of Guided-Wave Light Modulators with Filter-Type Coplanar Electrodes

    Masayuki IZUTSU  Takashi MIZUOCHI  Tadasi SUETA  

     
    PAPER

      Vol:
    E78-C No:1
      Page(s):
    55-60

    A filter-type coplanar parallel electrode with periodically loaded reactances is introduced to construct guided-wave light modulators of limited bandwidth. The device was built by using a Ti:LiNbO3 optical waveguide and was operated successfully at 633 nm. Measured 3 dB bandwidth was 1 GHz centered at 14.8 GHz. Required modulating power for 1 rad phase modulation was 67.6 mW.

  • Process Composition and Interleave Reduction in Parallel Process Specification

    Makoto TSUJIGADO  Teruo HIKITA  Jun GINBAYASHI  

     
    PAPER-Software Systems

      Vol:
    E78-D No:1
      Page(s):
    27-36

    In formal specification languages for parallel processes, such as CSP and LOTOS, algebraic laws for basic operators are provided that can be used to transform process expressions, and in particular, composition of processes can be calculated using these laws. Process composition can be used to simplify and improve the specification, and also to prove properties of the specification such as deadlock absence. We here test the practicality of process composition using CSP and suggest useful techniques, working in an example with nontrivial size and complexity. We emphasize that the size explosion of composed processes, caused by interleaving of the events of component processes, is a serious problem. Then we propose a technique, which we name two-way pipe, that can be used to reduce the size of the composed process, regarded as a program optimization at specification level.

  • Light Scattering and Reflection Properties in Polymer Dispersed Liquid Crystal Cells with Memory Effects

    Rumiko YAMAGUCHI  Susumu SATO  

     
    PAPER-Electronic Displays

      Vol:
    E78-C No:1
      Page(s):
    106-110

    Memory type polymer dispersed liquid crystal (PDLC) can be applied to a thermal addressing display device cell. Making use of its easy fabrication of large area display using flexible film substrate, the PDLC film can be used as reusable paper for direct-view mode display. In this study, memory type PDLC cells are prepared with an aluminum reflector deposited onto one side of the substrate and the reflection property in the PDLC cell with the reflector is clarified and compared to that without the reflector in the off-, on- and memory-states. The increase of contrast ratio and the decrease of driving voltage can be concurrently realized by decreasing the cell thickness by attaching the reflector. In addition, the reflected light in the off-state is bright and colorless due to the reflector, as compared with the weak, bluish reflected light in the cell without the reflector. Reflected light in the on-state and the memory-state are tinged with blue.

  • Specification Description Supporting Method of Telecommunications Networks Management Using Information Model and Process Model

    Ryutaro MATSUMURA  Osamu MIYAGISHI  

     
    PAPER

      Vol:
    E78-B No:1
      Page(s):
    39-46

    Managed Objects (MOs) can be specified by the combination of a static information model and a dynamic process model. First, this paper presents a mapping of attributes from a process model diagram to an information model diagram. Then, it introduces a concept of topology into these two models and proposes a hypothesis about the relationship of topology in these two models. To explicitly explain the hypothesis, it can be stated that all attributes of incoming or outgoing data related to a process in a process model are mapped to an information model where these attributes are interconnected by an explicit relationship which corresponds to a specific meaning, such as physical containment or logical connection. From an intuitive perspective, it can be said that if two attributes have a close topological relationship in a process model, the mapped attributes also have a close topological relationship in an information model. This hypothesis provides clues for determining whether there is an error in an attribute either in the process model or in the information model. By examining the way attributes of incoming or outgoing data related to a process are mapped to an information model, we can detect whether there is an error with respect to the process. The error correction is performed with the assistance of probability analysis. The method of error detection and correction can be implemented in a computer aided tool. Then, error detection on the attribute level becomes automatic, and error correction on the attribute level becomes interactive through the computer aided tool. Finally, the validity of the hypothesis is confirmed by analyzing ITU-T Recommendation M.3100. The specification of the fabric object class defined in M.3 100 is transformed into these two models and the hypothesis is validated for the analysis of the mapping between these two models.

37401-37420hit(42756hit)