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4161-4180hit(4570hit)

  • Electromagnetic Emissions from Atmospheric Pressure Gas Discharges

    Jen-Shih CHANG  

     
    INVITED PAPER

      Vol:
    E79-B No:4
      Page(s):
    447-456

    Over the past few years, many industrial processes have switched to electrical processes from conventional fossil fuel as a primary energy source, since electricity can be transmitted more economically than the transport of fossil fuels, as well as less pollution problems and labour- and spacesaving nature. For the environmental protections, ozone generation for water treatments, and decomposition of pollution gases such as SOx, NOx, COx, etc., by high pressure gas discharge processes become an important research subject. However, due to the early stage of development, the EMC problem is not yet well considered. In this review, we try to address the EMC problem in the various atmospheric pressure gas discharge processing techniques and identify future needs of research.

  • Electromagnetic Radiation Noise from Surface Gas Discharges-Mechanisms of Propagation, Coupling and Formation

    Keiichi UCHIMURA  Shuichi NITTA  Jen-Shih CHANG  

     
    PAPER

      Vol:
    E79-B No:4
      Page(s):
    490-496

    Surface discharge is widely used for industrial ozonizers and toxic gas treatments, and is noise source. In this paper, an experimental investigation from the point of view of electromagnetic compatibility (EMC) has been conducted to evaluate the noise characteristics of surface discharge combustion flue gas cleaning systems. Mechanisms of propagation, coupling and formation are proposed based on the experimental observations.

  • Effects of 50 to 200-keV Electrons by BEASTLI Method on Semiconductor Devices

    Fumio MIZUNO  Satoru YAMADA  Tsunao ONO  

     
    PAPER-Device Issues

      Vol:
    E79-C No:3
      Page(s):
    392-397

    We studied effects of 50-200-keV electrons on semiconductor devices using BEASTLI (backscattered electron assisting LSI inspection) method. When irradiating semiconduc-tor devices with such high-energy electrons, we have to note two phenomena. The first is surface charging and the second is device damage. In our study of surface charging, we found that a net positive charge was formed on the device surface. The positive surface charges do not cause serious influence for observation so that we can inspect wafers without problems. The positive surface charging may be brought about because most incident electrons penetrate the device layer and reach the conducting substrate of the semiconductor device. For the device damage, we studied MOS devices which were sensitive to electron-beam irradiation. By applying a 400- annealing to electron-beam irradiated MOS devices, we could restore the initial characteris-tics of MOS devices. However, in order to recover hot-carrier degradation due to neutral traps, we had to apply a 900- annealing to the electron-beam irradiated MOS devices. Thus, BEASTLI could be successfully used by providing an apporopri-ate annealing to the electron-beam irradiated MOS devices.

  • Efficient Characterization of Complex H-Plane Waveguide π-Junction and Cross-Junctions*

    Zhewang MA  Eikichi YAMASHITA  

     
    PAPER-Microwave and Millimeter Wave Technology

      Vol:
    E79-C No:3
      Page(s):
    444-452

    An efficient full-wave approach for the accurate characterization of a H-plane waveguide π-junction with an inductive post and a waveguide cross-junction is proposed. By employing the port reflection coefficient method (PRCM), the analysis and solution procedures of these complex waveguide junctions are greatly simplified and only the calculation of field reflections caused by the simplest waveguide step-junction discontinuities are required. The reflections are easily determined by the mode-matching technique. Scattering parameters of these junctions are provided and discussed in terms of the working frequency and the geometrical dimensions of the junctions. Calculated results are compared with those of other papers and measurements, all show good agreement.

  • Attacking Method on Tanaka's Scheme**

    Kiyomichi ARAKI  Masato NAKAO  

     
    LETTER-Information Security

      Vol:
    E79-D No:3
      Page(s):
    247-248

    In this paper, we show a collusion attack on the novel and sophisticated ID-based non-interactive key sharing scheme proposed by Tanaka [2], [3]. It is based on a linear algebraic approach [4]. We discuss its complexity and provide numerical simulation results of the success probability in forging the shared keys.

  • Performance Analysis of Internally Unbuffered Large Scale ATM Switch with Bursty Traffic

    Yuji OIE  Kenji KAWAHARA  Masayuki MURATA  Hideo MIYAHARA  

     
    PAPER-Switching and Communication Processing

      Vol:
    E79-B No:3
      Page(s):
    412-423

    Many ATM switching modules with high performance have been proposed and analyzed. A development of a large scale ATM switching system (e.g., used as a central switch) is the key to realization of the broadband ISDN. However, the dimension of ATM switching ICs is limited by the technological and physical constraints on VLSI. A multistage switching configuration is one of the promising configurations for a large scale ATM switch. In this paper, we treat a 3-stage switching configuration with no internal bufferes; i.e., bufferless switches are employed at the first and second stages, and output buffered switches at the third stage. A short-term cell loss probability is analyzed in order to examine the influence of bursty traffic on performance of the bufferless switch used at the first two stages. Furthermore, we propose a 4-stage switching configuration with traffic distributors added at the first stage. This switch provides more paths between a pair of input and output ports than the 3-stage switching configuration mentioned above. A few schemes to distribute cells are compared. It is shown that the distributor successfully reduces the deterioration of cell loss probability due to bursty traffic by splitting incoming cells into several switching modules.

  • Simulation System for Resource Planning and Line Performance Evaluation of ASIC Manufacturing Lines

    Shinji NAKAMURA  Chisato HASHIMOTO  Akira SHINDO  Osamu MORI  Junro NOSE  

     
    PAPER-CIM/CAM

      Vol:
    E79-C No:3
      Page(s):
    290-300

    A new line simulator, SEMALIS has been developed. This simulator can handle complicated lot processings to maintain processing quality and efficient line operations to improve line performance. The current manufacturing line consists of five resource models: lot, process sequence, equipment, lot processing, and line operations. The parameters of these models are defined so as to accurately reflect the state of the line operations. From our simulation results, we confirmed that SEMALIS accurately identifies bottlenecks or starvations where equipment can be added or reduced to optimize equipment utilization through resource planning, and that SEMALIS can also be used to evaluate the long-term effects of line operating methods on the line performance of ASIC manufacturing lines.

  • Fiber-Oriented Wireless Systems for Intelligent Networks

    Kojiro ARAKI  Hiroyuki OHTSUKA  

     
    INVITED PAPER

      Vol:
    E79-B No:3
      Page(s):
    222-229

    This paper overviews fiber-oriented wireless communication systems, particularly in the area of microcell systems. The benefits of fiber-oriented wireless systems are discussed focusing on an application board scheme to facilitate new service deployment in light of intelligent networks. Dynamic range improvement technologies to remove interference are highlighted. Overall system performance is calculated for an economical FP-LD. Furthermore, effective modem use and a potential diversity technique are introduced. This strategy will play a role in realizing flexible fiber-optic subscriber networks.

  • G/D/1 Queueing Analysis by Discrete Time Modeling

    Kenji NAKAGAWA  

     
    LETTER-Communication Theory and Signals

      Vol:
    E79-A No:3
      Page(s):
    415-417

    G/D/1 is a theoretic model for ATM network queueing based on processing cells. We investigate the G/D/1 system by discrete time modeling. Takacs' combinatorial methods are applied to analyze the system performance. An approximation for the survivor function P[Q > q], which is the probability that the queue length Q in the stationary state exceeds q, is obtained. The obtained formula requires only very small computational complexity and gives good approximation for the true value of P[Q > q].

  • Simplified Formula for Estimating the Macroscopic Telephone Demand

    Hisao OIKAWA  Takao YAMAZAKI  Hidetoshi KIMURA  

     
    PAPER-Communication Networks and Services

      Vol:
    E79-B No:3
      Page(s):
    392-398

    Estimating the macroscopic demand for telephones is essential to long-term planning construction of telecommunication networks facilities. Although there are several useful forecast equations, they need some types and/or vast amounts of data that are sometimes unavailable, especially in developing countries. This paper presents a sophisticated telephone demand estimation technique that is based on the demands of residential and business users. It uses several parameters to estimate the increase in telephone demand. A simplified equation is also presented that is a function of only one parameter: normalized gross domestic product (GDP) per capita. This simplified equation is shown to be useful by using data for more than ten countries.

  • Partitioned-Bus and Variable-Width-Bus Scheme for Low Power Digital Processors

    Makoto IKEDA  Kunihiro ASADA  

     
    PAPER-Electronic Circuits

      Vol:
    E79-C No:3
      Page(s):
    424-429

    We propose a partitioned-bus architecture with a variable-width-bus scheme to reduce power consumption in bus lines in VLSIs. The partitioned-bus architecture (horizontal partitioning) restricts bus driving range to minimal, while the variable-width-bus scheme (vertical partitioning) uses additional tag lines so as to automatically indicate effective bus width with-out driving unnecessary bus lines depending on data to be transferred. Applying this method to a general purpose microprocessor, we demonstrate 30% and 35% power consumption reduction in bus lines, respectively for the partitioned-bus architecture and the variable-width-bus scheme, compared with the conventional bus architecture. Combining the both together, we show about 55% power consumption reduction in bus lines for typical applications. Increase in chip area for this architecture is about 30% compared with the conventional bus architecture.

  • High-Resolution Wafer Inspection Using the "in-lens SEM"

    Fumio MIZUNO  Satoru YAMADA  Tadashi OHTAKA  Nobuo TSUMAKI  Toshifumi KOIKE  

     
    PAPER-Particle/Defect Control and Analysis

      Vol:
    E79-C No:3
      Page(s):
    317-323

    A new electron-beam wafer inspection system has been developed. The system has a resolution of 5 nm or better, and is applicable to quarter-micron devices such as 256 Mbit DRAMs. The most remarkable feature of this system is that a specimen stage is built in the objective lens and allows a working distance (WD) of 0. "WD=0"minimizes the effect of lens aberrations, and maximizes the resolving power. Innovative designs to achieve WD=0 are as follows: (1)A large objective lens of 730-mm width 730-mm depth 620-mm height that serves as a specimen chamber, has been developed. (2)A hollow specimen stage made of non-magnetic materials has been developed.It allows the lower pole piece and magnetic coile of the objective lens inside it. (3)Acoustic motors made of non-magnetic materials are em-ployed for use in vacuum.

  • The Super-Multi-Tanh Technique for Bipolar Linear Transconductance Amplifiers

    Katsuji KIMURA  

     
    PAPER

      Vol:
    E79-A No:2
      Page(s):
    190-198

    A novel circuit design technique for bipolar linear transconductance amplifiers is presented. A triple-tail cell, which consists of three emitter-common transistors biased by a single tail current, is exchangeable with an emitter-coupled pair in the multi-tanh cell, such as a multi-tanh doublet, a multi-tanh triplet or a multi-tanh quad. Therefore, the multi-tanh technique is further theoretically expanded to the super-multi-tanh technique. In this paper, the super-multi-tanh technique is proposed and discussed, and furthermore, a super-multi-tanh doublet is verified with bipolar transistor-arrays and discrete resistors on a breadboard.

  • Multimode Chaos in Two Coupled Chaotic Oscillators with Hard Nonlinearities

    Yoshifumi NISHIO  Akio USHIDA  

     
    PAPER-Nonlinear Problems

      Vol:
    E79-A No:2
      Page(s):
    227-232

    In this study, multimode chaos observed from two coupled chaotic oscillators with hard nonlinearities is investigated. At first, a simple chaotic oscillator with hard nonlinearities is realized. It is confirmed that in this chaotic oscillator the origin is always asymptotically stable and that the solution, which is excited by giving relatively large initial conditions, undergoes period-doubling bifurcations and bifurcates to chaos. Next, the coexistence of four different modes of oscillations are observed from two coupled chaotic oscillators with hard nonlinearities by both of circuit experiments and computer calculations. One of the modes of oscillation is a nonresonant double-mode oscillation and this oscillation is stably generated even in the case that oscillation is chaotic. Namely, for this oscillation mode, chaotic oscillation and periodic oscillation can be simultaneously excited. This phenomenon has not been reported yet, and we name this phenomenon as double-mode chaos. Finally, the beat frequency of the double-mode chaos is confirmed to be changed by varying the value of the coupling capacitor.

  • A Non-uniform Discrete-Time Cellular Neural Network and Its Stability Analysis

    Chen HE  Akio USHIDE  

     
    LETTER-Neural Networks

      Vol:
    E79-A No:2
      Page(s):
    252-257

    In this study, we discuss a discrete-time cellular neural network (DTCNN) and its applications including convergence property and stability. Two theorems about the convergence condition of nonreciprocal non-uniform DTCNNs are described, which cover those of reciprocal one as a special case. Thus, it can be applied to wide classes of image processings, such as associative memories, multiple visual patterns recognition and others. Our DTCNN realized by the software simulation can largely reduce the computational time compared to the continuous-time CNN.

  • Hopfield Neural Network Learning Using Direct Gradient Descent of Energy Function

    Zheng TANG  Koichi TASHIMA  Hirofumi HEBISHIMA  Okihiko ISHIZUKA  Koichi TANNO  

     
    LETTER-Neural Networks

      Vol:
    E79-A No:2
      Page(s):
    258-261

    A direct gradient descent learning algorithm of energy function in Hopfield neural networks is proposed. The gradient descent learning is not performed on usual error functions, but the Hopfield energy functions directly. We demonstrate the algorithm by testing it on an analog-to-digital conversion and an associative memory problems.

  • TM-Scattering from Notches in a Parallel-Plate Waveguide

    Kyung H. PARK  Hyo J. EOM  Kazunori UCHIDA  

     
    LETTER-Communication Cable and Wave Guides

      Vol:
    E79-B No:2
      Page(s):
    202-204

    The problem of TM-mode scattering from the finite number of rectangular notches in a parallel plate waveguide is considered. The Fourier-transform is employed to obtain simultaneous equations and the simultaneous equations are solved to obtain an analytic solution in rapidly-convergent series. Numerical computations are performed to investigate the scattering behavior in terms of frequency and notch sizes. The presented theory is applicable to the analysis of scattering from the E-plane stubs in the rectangular waveguide.

  • Recursive Construction of the Systems Interpolating 1st- and 2nd-Order Information

    Kazumi HORIGUCHI  

     
    LETTER-Systems and Control

      Vol:
    E79-A No:1
      Page(s):
    134-137

    We present a recursive algorithm for constructing linear discrete-time systems which interpolate the desired 1st-and 2nd-order information. The recursive algorithm constructs a new system and connects it to the previous system in the cascade form every time new information is added. These procedures yield a practical realization of all the interpolants.

  • Predistorter Implementation to SLD in Fiber-Optic Wireless Systems

    Yuji ABURAKAWA  Hiroyuki OHTSUKA  

     
    PAPER-Optomicrowave Devices

      Vol:
    E79-C No:1
      Page(s):
    52-59

    This paper describes the performance of a predistorter implementation to a superluminescent diode (SLD) in fiber-optic wireless systems under the optical reflection. SLD intensity noise and 3rd-order intermodulation distortion (IM3) are experimentally compared with those of DFB-and FP-LD. It is observed that the IM3 of SLD has ideal 3rd characteristics and output noise remains unchanged against the number of optical connectors. It is also found that the predistorter reduces IM3 by 8 dB. Receiver sensitivity of the system is discussed from the view point of overall design. the BER performance of an SLD with predistorter using a π/4-QPSK signal as a subcarrier is also described theoretically and experimentally.

  • A New RSA-Type Scheme Based on Singular Cubic Curves (y-αx)(y-βx)x3(mod n)

    Hidenori KUWAKADO  Kenji KOYAMA  

     
    PAPER

      Vol:
    E79-A No:1
      Page(s):
    49-53

    This paper proposes a new RSA-type scheme over non-singular parts of singular cubic curves En(α,β):(y-αx)(y-βx)x3(mod n). In usual one-to-one communication, we prove that breaking the proposed scheme is not easier than breaking the RSA scheme for the whole ciphertexts. If encryption key e is larger than 19 for 512 bits modulus n, then the proposed scheme is secure against the Hastad attack in broadcast applications. A plaintext of two blocks, i.e., x and y coordinates in En(α,β), is encrypted to a ciphertext of three blocks, where the size of one block is log2n bits. The decryption speed ofthe proposed scheme is as fast as that of the RSA scheme for the even block plaintext.

4161-4180hit(4570hit)