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3381-3400hit(4570hit)

  • A Multimedia Architecture Extension for an Embedded RISC Processor

    Ichiro KURODA  Kouhei NADEHARA  

     
    PAPER-Digital Signal Processing

      Vol:
    E84-A No:9
      Page(s):
    2255-2260

    This paper presents a multimedia architecture extension design for a 200-MHz, 1.6-GOPS embedded RISC processor. The datapath architecture of the processor which realizes parallel execution of data transfer and SIMD (single instruction stream multiple data stream) parallel arithmetic operations is designed. Four SIMD parallel 16-bit MAC (multiply-accumulation) instructions are introduced with a symmetric rounding scheme which maximizes the accuracy of the 16-bit accumulation. This parallel 16-bit MAC on a 64-bit datapath is shown to be efficiently utilized for DSP applications such as the correlation and the matrix-vector multiplications in the multimedia RISC processor. By using the parallel MAC instruction with the symmetric rounding scheme, a 2D-IDCT which satisfies the IEEE1180 can be implemented in 202 cycles.

  • A Mathematical Theory for Available Operation of Network Systems Extraordinarily Complicated and Diversified on Large-Scales

    Kazuo HORIUCHI  

     
    INVITED PAPER

      Vol:
    E84-A No:9
      Page(s):
    2078-2083

    In this paper, we shall construct mathematical theory based on the concept of set-valued mappings, suitable for available operation of network systems extraordinarily complicated and diversified on large scales. Fundamental conditions for availability of system behaviors of such network systems are clarified in a form of fixed point theorem for system of set-valued mappings.

  • ECG Data Compression by Matching Pursuits with Multiscale Atoms

    Makoto NAKASHIZUKA  Kazuki NIWA  Hisakazu KIKUCHI  

     
    PAPER-Biomedical Signal Processing

      Vol:
    E84-A No:8
      Page(s):
    1919-1932

    In this paper, we propose an ECG waveform compression technique based on the matching pursuit. The matching pursuit is an iterative non-orthogonal signal expansion technique. A signal is decomposed to atoms in a function dictionary. The constraint to the dictionary is only the over-completeness to signals. The function dictionary can be defined to be best match to the structure of the ECG waveform. In this paper, we introduce the multiscale analysis to the implementation of inner product computations between signals and atoms in the matching pursuit iteration. The computational cost can be reduced by utilization of the filter bank of the multiscale analysis. We show the waveform approximation capability of the matching pursuit with multiscale analysis. We show that a simple 4-tap integer filter bank is enough to the approximation and compression of ECG waveforms. In ECG waveform compression, we apply the error feed-back procedure to the matching pursuit iteration to reduce the norm of the approximation error. Finally, actual ECG waveform compression by the proposed method are demonstrated. The proposed method achieve the compression by the factor 10 to 30. The compression ratio given by the proposed method is higher than the orthogonal wavelet transform coding in the range of the reconstruction precision lower than 9% in PRD.

  • Multi-Level QAM Transceivers with Adaptive Power Control in Fixed Wireless Channels

    Seong-Choon LEE  Yong-Hwan LEE  

     
    PAPER-Terrestrial Radio Communications

      Vol:
    E84-B No:8
      Page(s):
    2219-2226

    This paper considers the design of quadrature amplitude modulation (QAM) transceivers for fixed wireless communications. We propose the use of power control in the QAM transmitter (Tx) to obtain BER performance robust to fading. The gain of the Tx is adaptively adjusted to keep the power of the received signal nearly constant despite of the short term fading and the second multipath. The BER performance of the proposed scheme is analytically evaluated in fixed wireless channels with flat fading and frequency selective fading. Analytic and simulation results show that the use of power control in the Tx can provide the BER performance only about 1 dB inferior to that in additive white Gaussian noise (AWGN) channel.

  • Single-Parameter Characterizations of Schur Stability Property

    Takehiro MORI  Hideki KOKAME  

     
    LETTER-Systems and Control

      Vol:
    E84-A No:8
      Page(s):
    2061-2064

    New equivalent characterizations are derived for Schur stability property of real polynomials. They involve a single scalar parameter, which can be regarded as a freedom incorporated in the given polynomials so long as the stability is concerned. Possible applications of the expressions are suggested to the latest results for stability robustness analysis in parameter space. Further, an extension of the characterizations is made to the matrix case, yielding one-parameter expressions of Schur matrices.

  • Call Admission and Efficient Allocation for Delay Guarantees

    Yen-Ping CHU  Chin-Hsing CHEN  Kuan-Cheng LIN  

     
    PAPER-Network

      Vol:
    E84-D No:8
      Page(s):
    1039-1047

    ATM networks are connection-oriented. Making a call requires first sending a message to do an admission control to guarantee the connections' QoS (quality of service) in the network. In this paper, we focus on the problem of translating a global QoS requirement into a set of local QoS requirements in ATM networks. Usually, an end-user is only concerned with the QoS requirements on end-to-end basis and does not care about the local switching node QoS. Most of recent research efforts only focus on worst-case end-to-end delay bound but pay no attention to the problem of distributing the end-to-end delay bound to local switching node. After admission control, when the new connection is admitted to enter the network, they equally allocate the excess delay and reserve the same bandwidth at each switch along the path. But, this can not improve network utilization efficiently. It motivates us to design a novel local QoS requirement allocation scheme to get better performance. Using the number of maximum supportable connections as the performance index, we derive an optimal delay allocation (OPT) policy. In addition, we also proposed an analysis model to evaluate the proposed allocation scheme and equal allocation (EQ) scheme in a series of switching nodes with the Rate-controlled scheduling architecture, including a traffic shaper and a non-preemptive earliest-deadline-first scheduler. From the numerical results, we have shown the importance of allocation policy and explored the factors that affect the performance index.

  • A Remote Auscultation Support System Using Network

    Takao KANEKO  Takehiro MORIYA  Naoki IWAKAMI  

     
    PAPER-Medical Engineering

      Vol:
    E84-D No:8
      Page(s):
    1102-1111

    A remote auscultation support system was developed that compresses and records in real time the patient's breath sound and heart sound, obtained using a stethoscope, and sends this data to an attending doctor at a hospital via network. For real-time recording of the breath sound and heart sound, special-purpose, high-quality sound coding technology was developed and incorporated in the system. This sound coding technology enables the amount of data to be reduced to about 1/18 with virtually no deterioration of the properties of the auscultation sound, high-speed transmission of this data using network, and remote diagnosis of the auscultation sound by a medical specialist. The auscultation locations of each patient, together with the doctor, stethoscoper, and patient database are input into the system in advance at the hospital. At the patient's home or sanatorium, the auscultation sound is recorded according to a human body display that shows auscultation locations, and then sent to the hospital. To ensure patient confidentiality when the auscultation data is transmitted via network, the system scrambles the auscultation data and allows only the attending doctor to play and diagnose the auscultation sound. These features not only support an understanding of the condition of patients being treated at home, but they also enable the construction of an auscultation database for electronic charts that allows auscultation results to be shared within the hospital. When this remote auscultation support system was manufactured and its performance was assessed, virtually the same waveform was obtained for the recorded and played breath sound as for the original breath sound. Results showed that even at a sampling frequency of 11 kHz, remote diagnosis by a medical specialist was in fact possible. Furthermore, if auscultation data of 10 seconds per location for 10 locations is sent, the amount of data sent is only about 120 Kbytes. Since this amount of data converts to only about 25 pages of electronic mail text, even via the existing mobile network the auscultation sounds of many patients can be sent efficiently.

  • Validation of Rain/No-Rain Discrimination in the Standard TRMM Data Products 1B21 and 1C21

    Yuji OHSAKI  

     
    LETTER-Sensing

      Vol:
    E84-B No:8
      Page(s):
    2321-2325

    The Tropical Rainfall Measuring Mission (TRMM) is a United States-Japan joint project to measure rainfall from space. The first spaceborne rain radar is aboard the TRMM satellite. Rain/no-rain discrimination for the TRMM provides useful information for on-line data processing, storage, and post-processing analysis. In this paper, rain/no-rain discrimination for the TRMM has been validated through simulation and theory for the no-rain condition and by comparison with the ground-based radar data for rain conditions.

  • A DFT Controller for Instruction-Based Functional Test

    Hong-Sik KIM  Yong-Chun KIM  Sungho KANG  

     
    LETTER-VLSI Design Technology and CAD

      Vol:
    E84-A No:8
      Page(s):
    2070-2072

    This paper presents a DFT controller called as a TCU (Test Control Unit), which considerably improves the efficiency of the instruction-based functional test. Internal program/data buses are completely controllable and observable by the TCU during the test cycle. Diverse test modes of the TCU can increase the test efficiency and also provide complete access to program/data memories for functional test.

  • Embedded Lossless Wavelet-Based Image Coder Based on Successive Partition and Hybrid Bit Scanning

    Sheung-Yeung WANG  Lai-Man PO  

     
    PAPER-Image/Visual Signal Processing

      Vol:
    E84-A No:8
      Page(s):
    1863-1868

    A simple embedded lossless wavelet-based image coding algorithm called Successive Partition Zero Coder (SPZC), which uses hybrid bit scanning and non-causal adaptive context modelling, is proposed. By successive partition the wavelet coefficients in the spatial-frequency domain, the coefficients are ordered based on their absolute range. The prioritized coefficients are quantized in a successive approximation manner to generate a binary sequence, which is divided into subsources and encoded by arithmetic coder with non-causal adaptive context modelling. This method is suited for progressive image transmission (PIT). Experimental results show that SPZC outperforms other state-of-the-art coders such as SPIHT, CREW and LJPEG, but slightly inferior to ECECOW and CALIC in lossless mode. SPZC is simple in both context modelling and implementation.

  • Scaling Limit of the MOS Transistor--A Ballistic MOSFET--

    Kenji NATORI  

     
    INVITED PAPER

      Vol:
    E84-C No:8
      Page(s):
    1029-1036

    The current voltage characteristics of the ballistic metal oxide semiconductor field effect transistor (MOSFET) is reviewed. Reducing the carrier scattering by employing e.g. the intrinsic channel structure and the low temperature operation, nanometer to sub-0.1 µm size MOSFETs operation approaches the ballistic transport. The drain current is derived by analyzing the carrier behavior in the vicinity of the potential maximum in the channel. The carrier degeneracy and the predominant carrier distribution in the lowest subband around the maximum point have critical effects on the current value. A convenient approximation of the current in terms of terminal voltages is given. The current control mechanism is discussed with use of the "Injection velocity," with which carriers are injected from the source to the channel. An index to represent the ballisticity is given, and some published experimental data are analyzed. Transport of the quasi-ballistic MOSFET is discussed.

  • On Scalable Design of Bandwidth Brokers

    Zhi-Li ZHANG  Zhenhai DUAN  Yiwei Thomas HOU  

     
    PAPER-Internet Architecture

      Vol:
    E84-B No:8
      Page(s):
    2011-2025

    In this paper we study the scalability issue in the design of a centralized bandwidth broker model for dynamic control and management of QoS provisioning. We propose and develop a path-oriented, quota-based dynamic bandwidth allocation mechanism for efficient admission control operations under the centralized bandwidth broker model. We demonstrate that this dynamic bandwidth allocation mechanism can significantly reduce the overall number of QoS state accesses/updates, thereby increasing the overall call processing capability of the bandwidth broker. Based on the proposed dynamic bandwidth allocation mechanism, we also extend the centralized architecture with a single bandwidth broker to a hierarchically distributed architecture with multiple bandwidth brokers to further improve its scalability. Our study demonstrates that the bandwidth broker architecture can be designed in such a manner that it scales with the increase in the network capacity.

  • Jam-Packing: An Efficient QoS Service for Transferring Huge Files

    Tetsuya ONODA  Hui ZHANG  

     
    PAPER-Flow and Congestion Control

      Vol:
    E84-B No:8
      Page(s):
    2095-2104

    This paper proposes a novel file transfer scheme named "Jam-packing file transfer" that consists of a call admission control and a packet scheduling mechanism. This combination can efficiently multiplex the traffic of file transfer and provides a guaranteed delivery time. Simulation results show the highness of extreme the multiplexing efficiency as the improvement in call blocking probabilities compared with the conventional rate-based reservation schemes. Furthermore, simulations of the packet scheduling indicate that file deliveries are done at the predicted delivery time.

  • Performance Evaluation and Fairness Improvement of TCP over ATM GFR in FIFO-Based Mechanisms

    Yong-Gu JEON  Hong-Shik PARK  

     
    PAPER-Switching

      Vol:
    E84-B No:8
      Page(s):
    2227-2236

    Recently, the Guaranteed Frame Rate (GFR) service was proposed as a new service category of ATM to support non-realtime data applications and to provide the minimum rate guarantee. To keep the simplicity of GFR as much as possible and overcome defects of FIFO-based mechanisms, we propose a FIFO-based algorithm extending DFBA one to improve the fairness and provide the minimum rate guarantee for a wider range of Minimum Cell Rate (MCR). The key idea is controlling the number of CLP1 cells which are occupying more buffer space than the fair share even when the queue length is below Low Buffer Occupancy (LBO).

  • Wave Scattering from a Periodic Surface with Finite Extent: A Periodic Approach

    Junichi NAKAYAMA  Toyofumi MORIYAMA  Jiro YAMAKITA  

     
    LETTER-Electromagnetic Theory

      Vol:
    E84-C No:8
      Page(s):
    1111-1113

    As a method of analyzing the wave scattering from a finite periodic surface, this paper introduces a periodic approach. The approach first considers the wave diffraction by a periodic surface that is a superposition of surface profiles generated by displacing the finite periodic surface by every integer multiple of the period . It is pointed out that the Floquet solution for such a periodic case becomes an integral representation of the scattered field from the finite periodic surface when the period goes to infinity. A mathematical relation estimating the scattering amplitude for the finite periodic surface from the diffraction amplitude for the periodic surface is proposed. From some numerical examples, it is concluded that the scattering cross section for the finite periodic surface can be well estimated from the diffraction amplitude for a sufficiently large .

  • A Measure of Coefficient Quantization Errors for Linear Discrete-Time State-Space Systems

    Shumon SAITO  Masayuki KAWAMATA  

     
    PAPER-Digital Filter

      Vol:
    E84-A No:8
      Page(s):
    1815-1821

    This paper proposes a measure of coefficient quantization errors for linear discrete-time state-space systems. The proposed measure of state-space systems agrees with the actual output error variance since it is derived from the exact evaluation of the output error variance due to coefficient deviation. The measure in this paper is represented by the controllability and the observability gramians and the state covariance matrix of the system. When the variance of coefficient variations is very small, the proposed measure is identical to the conventional statistical sensitivity of state-space systems. This paper also proposes a method of synthesizing minimum measure structures. Numerical examples show that the proposed measure is in very good agreement with the actual output error variance, and that minimum measure structures have a very small degradation of the frequency characteristic due to coefficient quantization.

  • Robust Guaranteed Cost Control of Discrete-Time Uncertain Systems with Time Delays

    Jonghae KIM  

     
    LETTER-Systems and Control

      Vol:
    E84-A No:8
      Page(s):
    2065-2069

    This paper provides a new robust guaranteed cost controller design method for discrete parameter uncertain time delay systems. The result shows much tighter bound of guaranteed cost than that of existing paper. In order to get the optimal (minimum) value of guaranteed cost, an optimization problem is given by linear matrix inequality (LMI) technique. Also, the parameter uncertain systems with time delays in both state and control input are considered.

  • A Unified Estimation for Scheduled Controllers in Nonlinear Systems

    Seon-Ho LEE  Jong-Tae LIM  

     
    LETTER-Systems and Control

      Vol:
    E84-A No:7
      Page(s):
    1789-1792

    This letter focuses on the design of a unified estimator for scheduled control in nonlinear systems with unknown parameter. An estimation law with a finite convergence time is formulated to compute the unknown scheduling parameter that drives a scheduled controller. This estimator can also be extended to the types of scheduled controllers addressed in the literature.

  • A Fair Scheduling Algorithm for Wireless Packet Networks

    Mooryong JEONG  Hiroyuki MORIKAWA  Tomonori AOYAMA  

     
    PAPER

      Vol:
    E84-A No:7
      Page(s):
    1624-1635

    Fairness as defined in wireline network cannot be achieved in wireless packet networks due to the bursty and location-dependent channel errors of wireless link. Channel-state dependent scheduling and compensation mechanism for errored flows are generally employed to improve the fairness in wireless packet scheduling algorithms. Most of the wireless scheduling algorithms, however, have two common significant problems. One problem is that they operate incorrectly unless all flows have the same packet size. This is due to the incorrect lead-and-lag model and the swapping-based rough compensation mechanism of the algorithms. The other problem is the degradation of error-free flow during compensation. The root of the degradation is that the bandwidth for compensation cannot be reserved since it is very difficult to predict. In this paper, we introduce WGPS (Wireless General Processor Sharing) to define fairness in wireless networks and present PWGPS as a packetized algorithm of WGPS. In our method, lead and lag of all flows are defined in terms of virtual time which is flexible enough to deal with packet size differences. Further, compensation is done by increasing the service share of the errored flow to a predetermined amount Δ. This enables the maximum bandwidth for compensation can be estimated and thus reserved. Our method can be proved to achieve improved fairness as compared with the previous scheduling algorithms.

  • Microwave Simulator Based on the Finite-Element Method by Use of Commercial Tools

    Koichi HIRAYAMA  Yoshio HAYASHI  Masanori KOSHIBA  

     
    PAPER-Electromagnetics Simulation Techniques

      Vol:
    E84-C No:7
      Page(s):
    905-913

    Making up a microwave simulator is tried, which has an analysis method based on the finite-element method as a solver and commercial tools as a pre- and post-processor of a graphical user interface. The platform of this simulator is Windows, but, since the codes and configuration files to be created are common on Windows, Unix, and Linux, the simulator running on any platform may be made up at the same time, except a document on which all the commands of the simulator are embedded and executable. Using the simulator, the transmission properties of a 2- and 3-D waveguide discontinuity in a microwave circuit and eigenmodes of a 2- and 3-D waveguide are analyzed, and the computed results are presented in graphs of S parameters and plots of the electric field distribution.

3381-3400hit(4570hit)