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[Keyword] REM(1013hit)

821-840hit(1013hit)

  • A Simplification Algorithm for Calculation of the Mutual Information by Quantum Combined Measurement

    Shogo USAMI  Tsuyoshi Sasaki USUDA  Ichi TAKUMI  Masayasu HATA  

     
    PAPER-Quantum Information

      Vol:
    E82-A No:10
      Page(s):
    2185-2190

    Recently, the quantum information theory attracts much attention. In quantum information theory, the existence of superadditivity in capacity of a quantum channel was foreseen conventionally. So far, some examples of codes which show the superadditivity in capacity have been clarified. However in present stage, characteristics of superadditivity are not still clear up enough. The reason is as follows. All examples were shown by calculating the mutual information by quantum combined measurement, so that one had to solve the eigenvalue and the eigenvector problems. In this paper, we construct a simplification algorithm to calculate the mutual information by using square-root measurement as decoding process of quantum combined measurement. The eigenvalue and the eigenvector problems are avoided in the algorithm by using group covariancy of binary linear codes. Moreover, we derive the analytical solution of the mutual information for parity check codes with any length as an example of applying the simplification algorithm.

  • An Evaluation of Visual Fatigue in 3-D Displays: Focusing on the Mismatching of Convergence and Accommodation

    Toshiaki SUGIHARA  Tsutomu MIYASATO  Ryohei NAKATSU  

     
    PAPER

      Vol:
    E82-C No:10
      Page(s):
    1814-1822

    In this paper, we describe an experimental evaluation of visual fatigue in a binocular disparity type 3-D display system. To evaluate this fatigue, we use a subjective assessment method and focus on mismatching between convergence and accommodation, which is a major weakness of binocular disparity 3-D displays. For this subjective assessment, we use a newly-developed binocular disparity 3-D display system with a compensation function for accommodation. Because this equipment only allowed us to compare the terms of the mismatching itself, the evaluation is more accurate than similar previous works.

  • Traffic Measurement System with Trap and Polling Methods and Its Performance

    Ken'ichi KAWANISHI  Yoshitaka TAKAHASHI  Toyofumi TAKENAKA  

     
    PAPER-Communication Networks and Services

      Vol:
    E82-B No:10
      Page(s):
    1557-1565

    We propose a traffic measurement system which uses trap and polling methods. To obtain its performance we consider a queueing model with a single server and evaluate a packet delay. In our multi-cast traffic, packets are modeled as a batch with a batch size distribution {gk}. The batch arrival process is observed as two processes on the basis of batch size. For a batch whose size is more than or equal to a threshold L, the batch will be trapped by our traffic measurement system (in queueing model, it will enter a queue immediately after its arrival). For a batch whose size is less than L, it will be observed at a polling cycle T (in queueing model, it will be temporarily stored in a buffer and all these small batches will be cyclically noticed with a cycle T). We analyze this queueing model by a diffusion approximation and compare the packet delay observed by our traffic measurement system with the L=1 original batch arrival model. Evaluating the results of the diffusion approximation, we illustrate that our traffic measurement system has functions not only to give an accurate estimation of the mean waiting time but also reduce the number of measurements by choosing appropriate parameters L and T.

  • Fluctuation Theory of Interactive Communication Channels, by means of Set-Valued Mapping Concept

    Kazuo HORIUCHI  

     
    PAPER

      Vol:
    E82-A No:9
      Page(s):
    1818-1824

    In multi-media systems, the type of interactive communication channels is found almost everywhere and plays an important role, as well as the type of unilateral communication channels. In this report, we shall construct a fluctuation theory based on the concept of set-valued mappings, suitable for evaluation, control and operation of interactive communication channels in multi-media systems, complicated and diversified on large scales. Fundamental conditions for availability of such channels are clarified in a form of fixed point theorem for system of set-valued mappings.

  • On the Existence and Stability of Solutions in Self-Organizing Cortical Maps

    Anke MEYER-BASE  

     
    PAPER

      Vol:
    E82-A No:9
      Page(s):
    1883-1887

    We analyze the dynamics of self-organizing cortical maps under the influence of external stimuli. We show that if the map is a contraction, then the system has a unique equilibrium which is globally asymptotically stable; consequently the system acts as a stable encoder of external input stimuli. The system converges to a fixed point representing the steady-state of the neural activity which has as an upper bound the superposition of the spatial integrals of the weight function between neighboring neurons and the stimulus autocorrelation function. The proposed theory also includes nontrivial interesting solutions.

  • Texture Segmentation Using Separable and Non-Separable Wavelet Frames

    Jeng-Shyang PAN  Jing-Wein WANG  

     
    PAPER

      Vol:
    E82-A No:8
      Page(s):
    1463-1474

    In this paper, a new feature which is characterized by the extrema density of 2-D wavelet frames estimated at the output of the corresponding filter bank is proposed for texture segmentation. With and without feature selection, the discrimination ability of features based on pyramidal and tree-structured decompositions are comparatively studied using the extrema density, energy, and entropy as features, respectively. These comparisons are demonstrated with separable and non-separable wavelets. With the three-, four-, and five-category textured images from Brodatz album, it is observed that most performances with feature selection improve significantly than those without feature selection. In addition, the experimental results show that the extrema density-based measure performs best among the three types of features investigated. A Min-Min method based on genetic algorithms, which is a novel approach with the spatial separation criterion (SPC) as the evaluation function is presented to evaluate the segmentation performance of each subset of selected features. In this work, the SPC is defined as the Euclidean distance within class divided by the Euclidean distance between classes in the spatial domain. It is shown that with feature selection the tree-structured wavelet decomposition based on non-separable wavelet frames has better performances than the tree-structured wavelet decomposition based on separable wavelet frames and pyramidal decomposition based on separable and non-separable wavelet frames in the experiments. Finally, we compare to the segmentation results evaluated with the templates of the textured images and verify the effectiveness of the proposed criterion. Moreover, it is proved that the discriminatory characteristics of features do spread over all subbands from the feature selection vector.

  • Automated Millimeter-Wave On-Wafer Testing System

    Takayuki KATOH  Takuo KASHIWA  Hiroyuki HOSHI  Akira INOUE  Takahide ISHIKAWA  

     
    PAPER-Measurements

      Vol:
    E82-C No:7
      Page(s):
    1312-1317

    A novel millimeter-wave on-wafer CAT(Computer-Aided-Testing ) system has been developed for measurement of S-parameters and NF ( Noise figure ). For the S-parameter test system, we have developed a holder setup and installed it in a semi-automatic wafer prober so that the waveguide-based T/R module can be directly connected to a probe-head through fixed waveguides, which feature low insertion loss of less than 2 dB, from 75 GHz to 98 GHz. The accuracy of the developed test system was confirmed by measuring, with this system, a co-planar offset short pattern then comparing measured and simulated results. A good agreement between the measured and calculated, in both return loss and return phase successfully demonstrated the superiority of the system. A W-band NF test system with a system noise of less than 8 dB has been also developed to provide an on-wafer NF measurement capability with an accuracy of 0.3 dB. These S-parameter and NF test systems possess great advantages to achieve high-speed automatic MMIC testing up to W-band.

  • FDTD Analysis and Experiment of Fabry-Perot Cavities at 60 GHz

    Ronan SAULEAU  Philippe COQUET  Daniel THOUROUDE  Jean-Pierre DANIEL  Harunobu YUZAWA  Nobumitsu HIROSE  Toshiaki MATSUI  

     
    PAPER-Passive Devices and Circuits

      Vol:
    E82-C No:7
      Page(s):
    1139-1147

    The Finite-Difference Time-Domain (FDTD) method has been applied to study the scattering characteristics of Fabry-Perot cavities with infinite planar periodic surfaces. Periodic Boundary Conditions (PBC) are used to reduce the analysis to one unit periodic volume. Both dielectric and metallic losses are included in the algorithm using a frequency dependent formalism. This technique is used to study the frequency response of plane parallel Fabry-Perot cavities with square aperture metal mesh mirrors. These cavities are assumed to be illuminated by a normally incident plane wave. After a detailed description of the algorithm, we show theoretically the separate effects of dielectric and metal losses on the transmission coefficient of such cavities. We compare also simulation results to measurements, in the 60 GHz band, of resonant frequencies and Q factors of cavities with various mesh parameters.

  • Mechanical Stress Simulation for Highly Reliable Deep-Submicron Devices

    Hideo MIURA  Shuji IKEDA  

     
    INVITED PAPER

      Vol:
    E82-C No:6
      Page(s):
    830-838

    We have improved the mechanical reliability of deep-submicron semiconductor devices by applying a simulation technique. Typical kinds of damages that reduce the reliability are dislocations in silicon substrates, delamination or cracking of thin films, and deterioration of electronic characteristics of devices. The mechanical stress that develops in device structures is caused by not only mismatches in thermal expansion coefficients among thin film materials but also intrinsic stress of thin films such as poly-silicon and silicides. Fine patterning by dry etching makes sharp edges and they also cause stress concentration and thus high stress. The manufacturing processes in which stress mainly develops are isolation, gate formation, and interconnect formation. We have developed methods for reducing the stress in each of the above-mentioned process. This stress reduction is very effective for highly reliable manufacturing. Finally, we clarify the effect of the residual stress in transistor structures on shift in the electronic characteristics of MOS transistors.

  • Measurement-Based Mathematical Active Device Modeling for High Frequency Circuit Simulation

    David E. ROOT  

     
    INVITED PAPER

      Vol:
    E82-C No:6
      Page(s):
    924-936

    Measurement-based mathematical modeling is an attractive approach for simulating, accurately and efficiently, circuits based on active devices from a diverse range of constantly evolving processes and technologies. The principle of the measurement-based approach is that it is often most practical to characterize the device with various high-frequency measurements, and then mathematically transform the data to produce predictive device dynamical models for small-signal (linear) and large-signal (nonlinear) circuit design purposes. There are many mathematical, physical, and measurement considerations, however, that must be incorporated into any sound framework for successful measurement-based modeling. This paper will review some foundations of the subject and discuss some future trends. Review topics include constructing nonlinear constitutive relations from linear data parameterized by operating point and conservation laws including terminal charge conservation and energy conservation. Recent advances and trends will be discussed, such as pulsed I-V and pulsed S-parameter characterization with implications for electro-thermal and dispersive dynamical models, nonlinear wave-form measurements, and the relationship to some black-box behavioral modeling approaches.

  • Adaptive Control Design for Linear Time-Varying System Based on Internal Model Principle

    Koichi HIDAKA  Hiromitsu OHMORI  Akira SANO  

     
    PAPER-Systems and Control

      Vol:
    E82-A No:6
      Page(s):
    1047-1054

    In this paper, we propose a new adaptive control system design using internal model principle (IMP) for a bounded polynomial parameters. In this method, we regard time varying parameters as variable disturbance and design an estimating law used the internal model of the disturbance so that the law is able to rejected the effectness of the disturbance. Our method has the features that the tracking error can converge to zero. Furthermore, we give a sufficient condition for the stability based on a small-gain theorem. The condition shows that our proposed method relax the stability condition more than the conventional methods based on a passivity theorem. Finally, we contain a numerical simulation to show an effect of our system.

  • An Integrated Call Admission Control in ATM Networks

    SuKyoung LEE  Jooseok SONG  

     
    PAPER-Communication Networks and Services

      Vol:
    E82-B No:5
      Page(s):
    704-711

    A scheme is proposed to exploit statistical multiplexing to support connections with diverse characteristics and requirements. Previous designs on measurement-based admission control mainly focused on strategies that consider the worst case traffic source model to guarantee QoS bounds for all connections. In this paper, we develop a simple mechanism in which statistical multiplexing gain as well as QoS is considered to achieve higher bandwidth utilization. An accurate formula for the cell loss probability which combines measurments with the Gaussian approximation is presented for a new traffic model. Furthermore we enhance the performance of this mechanism through real-time measurements of traffic and monitoring of QoS.

  • Efficient Computation of the Characteristic Polynomial of a Polynomial Matrix

    Takuya KITAMOTO  

     
    PAPER-Numerical Analysis and Optimization

      Vol:
    E82-A No:5
      Page(s):
    842-848

    This paper presents an efficient algorithm to compute the characteristic polynomial of a polynomial matrix. We impose the following condition on given polynomial matrix M. Let M0 be the constant part of M, i. e. M0 M ( mod (y,,z)), where y,,z are indeterminates in M. Then, all eigenvalues of M0 must be distinct. In this case, the minimal polynomial of M and the characteristic polynomial of M agree, i. e. the characteristic polynomial f(x,y,,z) | x E M | is the minimal degree (w. r. t. x) polynomial satisfying f(M,y,,z) 0. We use this fact to compute f(x,y,,z). More concretely, we determine the coefficients of f(x,y,,z) little by little with basic matrix operations, which makes the algorithm quite efficient. Numerical experiments are given to compare the algorithm with conventional ones.

  • Test Structure for Characterizing Capacitance Matrix of Multi-Layer Interconnects in VLSI

    Tetsuhisa MIDO  Hiroshi ITO  Kunihiro ASADA  

     
    PAPER

      Vol:
    E82-C No:4
      Page(s):
    570-575

    A compact new test structure using shift register circuits for extracting components of the capacitance matrix of the multi-layer interconnections has been proposed. An extraction method of the capacitance matrix is also presented. As a result of fabrication, capacitance values obtained by measurement are in good agreement with the numerical calculation. We also showed an estimation method of the measurement errors.

  • A Traffic Measurement Tool for IP-Based Networks

    Masami ISHIKURA  Yoshihiro ITO  Osamu MAESHIMA  Tohru ASAMI  

     
    PAPER

      Vol:
    E82-D No:4
      Page(s):
    756-761

    Today, many kinds of real-time applications are available over IP networks. It is important to measure the network performance for such applications before making use of real applications. Authors developed the general purpose traffic measurement tool for IP networks. This system can generate any kinds of traffic flexibly and calculate the network performance such as throughput, delay and loss ratio according to received packets. In this paper, the concept of this traffic measurement tool is described in detail, and several examples of network measurements are shown.

  • Estimation of Network Characteristics and Its Use in Improving Performance of Network Applications

    Ahmed ASHIR  Glenn MANSFIELD  Norio SHIRATORI  

     
    PAPER

      Vol:
    E82-D No:4
      Page(s):
    747-755

    Network applications such as FTP, WWW, Mirroring etc. are presently operated with little or no knowledge about the characteristics of the underlying network. These applications could operate more efficiently if the characteristics of the network are known and/or are made available to the concerned application. But network characteristics are hard to come by. The IP Performance Metrics working group (IETF-IPPM-WG) is working on developing a set of metrics that will characterize Internet data delivery services (networks). Some tools are being developed for measurements of these metrics. These generally involve active measurements or require modificationsin applications. Both techniques have their drawbacks. In this work, we show a new and more practical approach of estimating network characteristics. This involves gathering and analyzing the network's experience. The experience is in the form of traffic statistics, information distilled from management related activities and ubiquitously available logs (squid access logs, mail logs, ftp logs etc. ) of network applications. An analysis of this experience provides an estimate of the characteristics of the underlying network. To evaluate the concept we have developed and experimented with a system wherein the network characteristics are generated by analyzing the logs and traffic statistics. The network characteristics are made available to network clients and administrators by Network Performance Metric (NPM) servers. These servers are accessed using standard network management protocols. Results of the evaluation are presented and a framework for efficient operation of network operations, using the network characteristics is outlined.

  • A Stochastic Evaluation Method on the Elimination of Background Sound Noises with Aid of Vibration Information and Its Experiment

    Kiminobu NISHIMURA  Mitsuo OHTA  

     
    PAPER

      Vol:
    E82-A No:4
      Page(s):
    597-604

    Under a contamination of background sound noises, it seems difficult especially in a real working situation to evaluate various type statistics of only an objective sound signal fluctuation. In many cases of the noise evaluation, some signal processing method have been employed to eliminate the effect of background sound noises by first measuring emitted sound levels. In this study, a new evaluation method of sound level fluctuation is proposed in principle on the basis of the measurement of heterogeneous physical quantity other than sound pressures or sound levels to eliminate the effect of background sound noises. Though the theoretical analysis on acoustical emission caused by a mechanical vibration seems very difficult in a working situation, the sound noise fluctuation emitted only from an objective sound source can be effectively evaluated through its related vibration measurement by employing a fairly unified stochastic method proposed on the basis of a generalized regression analysis between sound and vibration. Here, the regression coefficients are determined by employing the least squares error method to minimize the mean square of estimation error to illustrate well the sound data by means of vibration data. Finally, the effectiveness of proposed method has been experimentally applied to the sound noise evaluation of a jigsaw.

  • Optimum, Stable, and Fair Flow Control for Packet Networks

    Hideki SATOH  

     
    PAPER-Switching and Communication Processing

      Vol:
    E82-B No:3
      Page(s):
    489-499

    The author proposes a flow control scheme which derives the optimal packet transmission rate from the ACKs of the sending packets. The optimization is based on mathematical programming such as the extremal method and least-squares method. The author proves that the proposed method is fair when the RTT and thepacket length of each sender are the same. It is also shown that the sufficient condition for the proposed method to be optimal and stable generally holds true in packet networks. The performances are examined by computer simulations, and it is found that high throughput is obtained regardless of the network structure.

  • Automated Detection and Removal of Clouds and Their Shadows from Landsat TM Images

    Bin WANG  Atsuo ONO  Kanako MURAMATSU  Noboru FUJIWARA  

     
    PAPER-Image Processing,Computer Graphics and Pattern Recognition

      Vol:
    E82-D No:2
      Page(s):
    453-460

    In this paper, a scheme to remove clouds and their shadows from remotely sensed images of Landsat TM over land has been proposed. The scheme uses the image fusion technique to automatically recognize and remove contamination of clouds and their shadows, and integrate complementary information into the composite image from multitemporal images. The cloud regions can be detected on the basis of the reflectance differences with the other regions. Based on the fact that shadows smooth the brightness changes of the ground, the shadow regions can be detected successfully by means of wavelet transform. Further, an area-based detection rule is developed in this paper and the multispectral characteristics of Landsat TM images are used to alleviate the computational load. Because the wavelet transform is adopted for the image fusion, artifacts are invisible in the fused images. Finally, the performance of the proposed scheme is demonstrated experimentally.

  • Transfer Function Matrix Measurement of AWG Multi/Demulti-Plexers

    Kazunari HARADA  Kenji SHIMIZU  Nobuhiro SUGANO  Teruhiko KUDOU  Takeshi OZEKI  

     
    PAPER-Photonic WDM Devices

      Vol:
    E82-C No:2
      Page(s):
    349-353

    Wavelength Division Multiplex (WDM) photonic networks are expected as key for global communication infrastructure. The accurate measurement methods for AWG-MUX/DMUX are desirable for WDM network design. We measured a transfer function matrix of an AWG-MUX to find that polarization mode dispersion (PMD) and polarization dependent loss (PDL) shows the bandpass characteristics, which may limit the maximum size and the bit rate of the system. These bandpass characteristics of PMD and PDL are reproduced by a simple AWG-MUX model: The phase constant difference of 0.5% between orthogonal modes in arrayed waveguides is sufficient to obtain the measured passband characteristics of PMD and PDL. We find phase distribution difference between two orthogonal modes in the arrayed waveguide grating gives arise to complex PMD.

821-840hit(1013hit)