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21401-21420hit(30728hit)

  • Heart Sound Recognition through Analysis of Wavelet Transform and Neural Network

    Jun-Pyo HONG  Jung-Jun LEE  Sang-Bong JUNG  Seung-Hong HONG  

     
    PAPER-Medical Engineering

      Vol:
    E86-D No:6
      Page(s):
    1116-1121

    Heart sound is an acoustic wave generated by the mechanical movement of the heart and blood flow, and is a complicated, non-stationary signal composed of many signal sources. It can be divided into normal heart sounds and heart murmurs. Murmurs are abnormal signals that appear over wider ranges of frequency than normal heart sounds. They are generated at random spots in the whole period of heart sounds. The recognition of heart sounds is to differentiate heart murmurs through patterns that appear according to the generation time of murmurs. In this paper, a group of heart sounds was classified into normal heart sounds, pre-systolic murmurs, early systolic murmurs, late systolic murmurs, early diastolic murmurs, and continuous murmurs. The suggested algorithm was standardized by re-sampling and then added as an input to the neural network through wavelet transform. The neural network used Error Back - Propagation algorithm, which is a representative learning method, and controlled the number of hidden layers and the learning rate for optimal construction of networks. As a result of recognition, the suggested algorithm obtained a higher recognition rate than that of existing research methods. The best result was obtained with the average of 88% of the recognition rate when it consisted of 15 hidden layers. The suggested algorithm was considered effective for the recognition of automatic diagnosis of heart sound recognition programs.

  • VLSI Implementation for Fuzzy Membership-Function Generator

    Pei-Yin CHEN  

     
    LETTER-VLSI Systems

      Vol:
    E86-D No:6
      Page(s):
    1122-1125

    Correct and quick generation of a membership function is the key point when we implement a real-time fuzzy logic controller. In this Letter, we presented two efficient VLSI architectures, one to generate triangle-shaped and the other to generate trapezoid-shaped membership functions. Simulation results show that our designs require lower hardware cost but achieve faster working rate.

  • Wireless QoS Resource Cooperation Management for CDMA Packet Mobile Communication Systems

    Lan CHEN  Hidetoshi KAYAMA  Narumi UMEDA  

     
    PAPER-Wireless Communication Technology

      Vol:
    E86-B No:6
      Page(s):
    1927-1935

    The IMT-2000 service launched in 2001 in Japan is expected to popularize multimedia services such as videophone, visual mail, video, and music distribution. With the rapidly increasing demand for high-speed mobile multimedia and the need to support diversified requirements of users, wireless Quality of Service (QoS) resource management has become an important and challenging issue. In order to improve the system capacity and rate of satisfied users, in this paper, a novel wireless QoS resource management scheme is proposed to carry out radio resource cooperative control among base stations. Computer simulations indicate that the proposed QoS resource cooperative control exhibits superior performance over conventional ones, and that a higher rate of satisfied users is achieved.

  • Robust Control with Adaptive Compensation Input for Linear Uncertain Systems

    Hidetoshi OYA  Kojiro HAGINO  

     
    PAPER-Systems and Control

      Vol:
    E86-A No:6
      Page(s):
    1517-1524

    This paper deals with a design problem of a robust controller which achieves not only robust stability but also a performance robustness for linear systems with structured uncertainties satisfying matching condition. The performance robustness means that comparing the transient behavior of the uncertain system with a desired one generated by the nominal system, the deterioration of control performance is suppressed. In this approach, the control law consists of a state feedback with the fixed gain designed by using the nominal system, a state feedback with an adaptive gain determined by a parameter adjustment law and a compensation input for the purpose of keeping transient behavior as closely as possible to the desirable one. We show the parameter adjustment law in order to guarantee robust stability and that the condition for the existence of the compensation input is equivalent to the Riccati equation for the standard linear quadratic control problem. Finally, numerical examples are presented.

  • A Proposal of Effective Compensation Method for IR Lamp Deterioration in NDIR Type Capnograph Systems

    Il-Yong PARK  Hee-Joon PARK  Jeong-Woo LEE  Shin-Won KANG  Jin-Ho CHO  

     
    LETTER

      Vol:
    E86-A No:6
      Page(s):
    1513-1516

    An effective compensation method for the IR lamp deterioration in NDIR (non-dispersive infrared) capnograph system is proposed. The optical chamber with two IR (infrared) lamps has been designed newly and an electronic hardware for the control of lamp intensity has been implemented. After applying the proposed optical chamber and the reference lamp control circuit to the NDIR type capnograph system, it is identified that the proposed method can compensate the lamp deterioration effectively.

  • An Improved Configuration for Radio over Fiber Transmission with Remote Local-Oscillator Delivery by Using Two Dual-Mach-Zehnder Modulators in Parallel

    Ming-Tuo ZHOU  Awnashilal B. SHARMA  Jian-Guo ZHANG  Forhadul PARVEZ  

     
    PAPER

      Vol:
    E86-A No:6
      Page(s):
    1374-1381

    A simple configuration for millimeter-wave fiber-wireless transmission, with remote local-oscillator (LO) delivery from the central office, both for the uplink and for the downlink, and a simple, cost-effective, base-station solution is proposed. Under the assumption of using commercially available components and a conventional single-mode fiber (with dispersion of 17 ps/nm/km at 1.55 µm), our numerical results show that, with a laser linewidth of 150 MHz, a laser power of 0 dBm and an optical gain of only 6 dB, it is possible to transmit, without repeaters, data rates of 622 Mbit/s across about 18 km at a bit-error-rate of 10-9. By increasing the optical gain to 24 dB, the link length can be increased to approximately 67 km for a laser linewidth of 75 MHz and to 78 km for a laser linewidth 1 MHz.

  • Characterization of Movie Contents and Its Impact for Traffic Design

    Arata KOIKE  Satoko TAKIGAWA  Kiyoka TAKEDA  Akihisa KOBAYASHI  Masashi MORIMOTO  Konosuke KAWASHIMA  

     
    PAPER-Traffic Control in CDNs

      Vol:
    E86-B No:6
      Page(s):
    1839-1848

    In this paper, we first investigate the characteristics of movie contents over the Internet. As in the previous studies, we found the lognormal-distribution well fits the distribution of file size for the whole set of general movie contents. When we specifically focus on the subset that consists of movie trailers, however, it shows different distribution from the lognormal-distribution. Our analysis shows it is similar to an exponential-distribution. We here assume that movie trailers are one of the relevant contents for Contents Delivery Networks (CDN) or Peer-to-Peer (P2P) file exchange communities. We further studies the relationship between playing duration and file size for the movie trailers and we did not find any linear correlation among them. We next consider bandwidth requirements to retrieve movie trailer contents. Our objective is to make it possible for user to view the contents in real-time. Many previous studies investigate bandwidth requirement based only on the file size distribution. In this paper, we analyze the traffic design criteria for CDN or P2P by taking into account both of the results for the file size distribution and the relationship between playing duration and file size for movie trailers. Simulation studies reveal the impact for the bandwidth requirement.

  • Vector Quantization Codebook Design Using the Law-of-the-Jungle Algorithm

    Hiroyuki TAKIZAWA  Taira NAKAJIMA  Kentaro SANO  Hiroaki KOBAYASHI  Tadao NAKAMURA  

     
    PAPER-Image Processing, Image Pattern Recognition

      Vol:
    E86-D No:6
      Page(s):
    1068-1077

    The equidistortion principle[1] has recently been proposed as a basic principle for design of an optimal vector quantization (VQ) codebook. The equidistortion principle adjusts all codebook vectors such that they have the same contribution to quantization error. This paper introduces a novel VQ codebook design algorithm based on the equidistortion principle. The proposed algorithm is a variant of the law-of-the-jungle algorithm (LOJ), which duplicates useful codebook vectors and removes useless vectors. Due to the LOJ mechanism, the proposed algorithm can establish the equidistortion condition without wasting learning steps. This is significantly effective in preventing performance degradation caused when initial states of codebook vectors are improper to find an optimal codebook. Therefore, even in the case of improper initialization, the proposed algorithm can achieve minimization of quantization error based on the equidistortion principle. Performance of the proposed algorithm is discussed through experimental results.

  • Bayes Rule for MAC State Sojourn Time Supporting Packet Data Service in CDMA Wireless Cellular Networks

    Cheon Won CHOI  Ho-Kyoung LEE  

     
    PAPER

      Vol:
    E86-A No:6
      Page(s):
    1421-1429

    In provisioning packet data service on wireless cellular networks, a scheme of altering connection status between mobile and base stations appeared with an effort to utilize resource during idle periods. A critical issue in such scheme of sojourn and transition on the connection states is to determine a maximum time to sojourn at each state. An excessive sojourn time leads to resource invasion by inactive stations, while a high cost of re-establishing connection components is imposed by an insufficient sojourn. Thus, the maximum sojourn times must be optimized in consideration of the two conflicting arguments. In this paper, we consider a generic scheme of connection status transitions and formulate a decision problem to determine maximum sojourn times by introducing a loss function which reflects the cost of connection re-establishment as well as the loss induced by inefficient resource usage. From the decision problem, we derive an optimal value for maximum sojourn time, identified as Bayes rule, by observing the delay time of last packet to have posterior information about the length of upcoming idle period. From the analytical results, we show the Bayes sojourn time is trivial under a constraint on loss coefficients when packet arrivals follow a Poisson process.

  • Impedance Characteristic Analysis of an Axial Slot Antenna on a Sectoral Cylindrical Cavity Excited by a Probe Using Method of Moments

    Rangsan WONGSAN  Chuwong PHONGCHAROENPANICH  Monai KRAIRIKSH  Jun-ichi TAKADA  

     
    PAPER

      Vol:
    E86-A No:6
      Page(s):
    1364-1373

    This paper presents the analysis of the impedance characteristics of a sectoral cylindrical cavity-backed axial slot antenna excited by a probe. The integral equations are derived based on boundary conditions of the proposed structure and they are expressed in terms of dyadic Green functions and unknown current densities. The dyadic Green functions are obtained by using the eigenfunction expansion method together with application of scattering superposition techniques. The unknown current densities are solved by the Method of Moments. The input impedance is subsequently determined from the unknown electric current density at the probe. Numerical results of input impedance and return loss are demonstrated as functions of frequency for various parameters such as cavity length, cavity radius ratio, slot location in φ direction, slot length and probe length. Calculated results are validated by the measurements. At the operating frequency, it is found that the result is sufficiently accurate. The results from this study are very useful for the design of a sectoral cylindrical cavity-backed axial slot array antenna excited by a probe with omnidirectional beam radiation.

  • A Study on Real-Time Implementation of the View Interpolation System

    Dae-Hyun KIM  Jung-Hoon KIM  Yong-In YOON  In-Hwan OH  Jong-Soo CHOI  

     
    PAPER

      Vol:
    E86-A No:6
      Page(s):
    1344-1352

    In this paper, we propose an algorithm that automatically generates the intermediate scenes using the bidirectional disparity morphing (BDM) from the parallel stereo images. The two-step search strategy is used for speeding up the computation of the bidirectional disparity map and three occluding patterns are used for smoothing the computed disparities more elaborately. Using the bidirectional disparity map, we interpolate the left and the right image to their intermediate scenes. Then we dissolve two interpolated images into the desired intermediate scene which the holes are removed and the effect of the disparity estimation errors is minimized. We implemented the proposed algorithm on TM1300 supported by TriMedia using pSOSytem which enables to do multiprocessing. As a result, we can interpolate the high-quality intermediate scenes with real-time process.

  • Adaptive Noise Reduction of Biomedical Signals with Improved Multiplication Free Adaptive Digital Filter

    Dal Hwan YOON  Chi Ho LIN  

     
    PAPER

      Vol:
    E86-A No:6
      Page(s):
    1326-1334

    This paper proposes the IMADF (improved multiplication-free adaptive digital filter) algorithm to cancel the background noise that spans nearly all frequency bandwidths in biomedical signals. Under conditions of zero-mean, wide-sense stationary and white Gaussian noise, we analyze the convergence characteristics of the IMADF with a FSE (fractionally-spaced equalizer). In the experimental results, the IMADF algorithm has the advantage in which has superior to a condition of low-frequency and slow data speed. This application gives an important significance in ensuring the objectivity of clinical information and in promoting the representation and the disease diagnosis.

  • Adaptive Dynamic Co-interference Cancellation Algorithm for Wireless LAN

    Joon-il SONG  Jun-Seok LIM  Koeng-Mo SUNG  

     
    LETTER-Wireless Communication Technology

      Vol:
    E86-B No:6
      Page(s):
    2041-2044

    Wireless LAN (WLAN) systems transmit and receive via a common frequency band. In this band, signals of other wireless applications operate on a WLAN beamformer as interferences, and so the problem in adaptive antenna is increasing the canceling performance in the presence of moving interference sources. The performance of conventional adaptive beamformer is severely degraded and the robust adaptive beamformer must be equipped with additional sensors to obtain desired performances. Therefore, in order to avoid having to install additional sensors, an efficient algorithm is necessary. In this paper, we introduce a fast adaptive algorithm with variable forgetting factor, which does not require any further additional modifications. Through computer simulations, we can obtain better performances than those of other techniques under a variety of operating conditions.

  • A Dimensionality Reduction Method for Efficient Search of High-Dimensional Databases

    Zaher AGHBARI  Kunihiko KANEKO  Akifumi MAKINOUCHI  

     
    PAPER-Databases

      Vol:
    E86-D No:6
      Page(s):
    1032-1041

    In this paper, we present a novel approach for efficient search of high-dimensional databases, such as video shots. The idea is to map feature vectors from the high-dimensional feature space into a point in a low-dimensional distance space. Then, a spatial access method, such as an R-tree, is used to cluster these points based on their distances in the low-dimensional space. Our mapping method, called topological mapping, guarantees no false dismissals in the result of a query. However, the result of a query might contain some false alarms. Hence, two refinement steps are performed to remove these false alarms. Comparative experiments on a database of video shots show the superior efficiency of the topological mapping method over other known methods.

  • A Simple Modeling Technique for Symmetric Inductors

    Ryuichi FUJIMOTO  Chihiro YOSHINO  Tetsuro ITAKURA  

     
    LETTER

      Vol:
    E86-C No:6
      Page(s):
    1093-1097

    A simple modeling technique for symmetric inductors is proposed. Using the proposed technique, all model parameters for an equivalent circuit of symmetric inductors are easily calculated from geometric, process and substrate resistance parameters without using electromagnetic (EM) simulators. Comparison of simulated results with measured results verifies the effectiveness of the proposed modeling technique up to 5 GHz with center-tapped or non-center-tapped configurations.

  • Extended One-Shot Decorrelating Detector for Asynchronous DS/CDMA Systems

    Jee Woong KANG  Kwang Bok (Ed) LEE  

     
    PAPER-Wireless Communication Technology

      Vol:
    E86-B No:6
      Page(s):
    1901-1909

    We propose an extended one-shot decorrelating detector (EOS-DD) which may be viewed as a generalized double window multiuser detector (DW-MD) for asynchronous direct-sequence code-division multiple-access (DS/CDMA) systems in frequency selective fading environments. The EOS-DD extends a processing window and the received signal over an extended window is utilized for decorrelating. The effects of the window size on BER performance are investigated by numerical analysis. Analysis and simulation show that the EOS-DD is superior to the one-shot decorrelating detector (OS-DD) and finite memory length truncated decorrelating detector (FIR-DD) in terms of noise enhancement and near-far resistance. It is also shown that the EOS-DD with window size 4 can provide significantly improved performance compared to the EOS-DD with window size 2.

  • Relational Interface for Natural Language-Based Information Sources

    Zenshiro KAWASAKI  Keiji SHIBATA  Masato TAJIMA  

     
    LETTER-Databases

      Vol:
    E86-D No:6
      Page(s):
    1139-1143

    This paper presents an extension of the database query language SQL to include queries against a database with natural language annotations. The proposed scheme is based on Concept Coupling Model, a language model for handling natural language sentence structures. Integration of the language model with the conventional relational data model provides a unified environment for manipulating information sources comprised of relational tables and natural language texts.

  • A 380-MHz CMOS Linear-in-dB Variable Gain Amplifier with Gain Compensation Techniques for CDMA Systems

    Osamu WATANABE  Mitsuyuki ASHIDA  Tetsuro ITAKURA  Shoji OTAKA  

     
    PAPER

      Vol:
    E86-C No:6
      Page(s):
    1069-1076

    A linear-in-dB VGA of the current-divider type is fabricated in 0.25 µm CMOS technology. Two gain compensation techniques are proposed in order to compensate the gain deviations due to a MOSFET which has a square-law characteristic or an exponential-law characteristic determined by its current density. Temperature compensation techniques are also proposed. Measure results obtained at 380 MHz are a gain range of 80 dB, a gain error of 3 dB, and an NF of 11 dB.

  • Carry Propagation Free Adder/Subtracter Using Adiabatic Dynamic CMOS Logic Circuit Technology

    Yasuhiro TAKAHASHI  Kei-ichi KONTA  Kazukiyo TAKAHASHI  Michio YOKOYAMA  Kazuhiro SHOUNO  Mitsuru MIZUNUMA  

     
    PAPER

      Vol:
    E86-A No:6
      Page(s):
    1437-1444

    This paper describes a design of a Carry Propagation Free Adder/Subtracter (CPFA/S) VLSI using the Adiabatic Dynamic CMOS Logic (ADCL) circuit technology. Using a PSPICE simulator, energy dissipation of the ADCL 1 bit CPFA/S is compared with that of the CMOS 1 bit CPFA/S. As a result, energy dissipation of the proposed ADCL circuits is about 1/3 as high as that of the CMOS circuits. The transistors count, propagation-delay time and energy dissipation of the ADCL 4 bit CPFA/S are compared with those of the ADCL 4 bit Ripple Carry Adder/Subtracter (RCA/S). The transistors count and propagation-delay time are found to be reduced by 7.02% and 57.1%, respectively. Also, energy dissipation is found to be reduced by 78.4%. Circuit operation and performance are evaluated using a chain of the ADCL 1 bit CPFA/S fabricated in a 1.2 µm CMOS process. The experimental results show that addition and subtraction are operated with clock frequencies up to about 1 MHz. In addition, the total power dissipation of the ADCL 1 bit CPFA/S is 28.7 µW including the power supply.

  • A Linearly Constrained Minor Component Analysis Approach to Blind Adaptive Multiuser Interference Suppression

    Chiao-Chan HUANG  Zhi-Feng HUANG  Ann-Chen CHANG  

     
    LETTER-Wireless Communication Technology

      Vol:
    E86-B No:6
      Page(s):
    2024-2027

    A minor component analysis approach based on the generalized sidelobe canceler is presented to realize the blind suppression of multiple-access interference in multicarrier code division multiple access systems. With a rough user-code and timing estimations, this proposed method of less computation performs the same as minimum mean square error detectors and outperforms existing blind detectors. Simulation results illustrate the effectiveness of the blind multiuser detection.

21401-21420hit(30728hit)