The search functionality is under construction.
The search functionality is under construction.

Keyword Search Result

[Keyword] Z(5900hit)

5001-5020hit(5900hit)

  • A Multimedia Presentation System on Web -- Dynamic Homepage Approach

    Bal WANG  Ching-Fan CHEN  Min-Huei LIN  

     
    PAPER

      Vol:
    E82-D No:4
      Page(s):
    729-736

    Although there are many multimedia presentation systems on the market, they have some shortcomings and most of them only can work on one single computer, and few of them can work on Web. Thus, in the thesis we develop a network multimedia presentation system to let users easily design the multimedia presentation without restriction on technology or presentation time and place. Our system includes 3 main components: User Interface that includes temporal specification editor, spatial specification editor and multimedia object interface, Presentation Interface and Knowledge Base. There is a dynamic homepage generator in our system and we propose a displaying algorithm based on the Allen's theory, that there exist 13 temporal relationships between two intervals, for synchronizing the media objects.

  • Narrow-Band Phase-Rotating Phase-Shift Keying

    Hiroshi KUBO  Makoto MIYAKE  

     
    PAPER-Radio Communication

      Vol:
    E82-B No:4
      Page(s):
    627-635

    This paper proposes a phase-rotating phase-shift keying (PSK) modulation and shows that its narrow-band version is suitable for Viterbi equalization. The proposed PSK has the following features: 1) a spectrum shaping of the transmit/receive filters does not need to be restricted to the Nyquist criterion; 2) the transmitted data sequence is rotated for every symbol in order to reduce noise-correlation at the receiver. First, this paper discusses a performance degradation of bit error rate of Viterbi equalizers in the presence of the sampling timing offset or under time-dispersive frequency selective fading. Next, computer simulation confirms that π/2-shifted binary PSK with narrow-band spectrum shaping filter, which includes offset QPSK for its special case, solves the above mentioned performance degradation, keeping good spectrum efficiency equal to M-ary PSK.

  • Timing Synchronization Using the Reliability Check and Smoothing Algorithm in the Fading Channels

    Hyoung Kyu SONG  

     
    LETTER-Mobile Communication

      Vol:
    E82-B No:4
      Page(s):
    664-668

    A timing synchronization is required in the mobile station to determine the correct transmission timing of the mobile-to-base bursts. In this letter, a timing synchronization technique using the reliability check and smoothing algorithm is proposed for the GSM receiver. The reliability check scheme extends the usefulness of this algorithm into low SNR region. And also smoothing algorithm is carried out by a first-order filter with an asymmetric step size. Simulation results show that the proposed algorithm is adequate for timing recovery of GSM modem.

  • Linear Codes on Nonsingular Curves are Better than Those on Singular Curves

    Ryutaroh MATSUMOTO  

     
    PAPER-Information Theory and Coding Theory

      Vol:
    E82-A No:4
      Page(s):
    665-670

    Recently, Miura introduced a construction method of one-point algebraic geometry codes on singular curves, which is regarded as a generalization of one on nonsingular curves, and enables us to construct codes on wider class of algebraic curves. However, it is still not clear whether there really exist singular curves on which we can construct good codes that are never obtained from nonsingular curves. In this paper, we show that for fixed designed minimum distance in a wide range, the dimension of codes on a singular curve is smaller than or equal to that of the codes on its normalization, and the number of check symbols of the former codes is larger than that of the latter codes. This implies the optimality of nonsingular curves for code construction.

  • Speech Analysis with Blind Equalization Technique

    Munehiro NAMBA  Yoshihisa ISHIDA  

     
    PAPER

      Vol:
    E82-A No:4
      Page(s):
    564-571

    The conventional linear prediction can be viewed as a constrained blind equalization problem that has gained a lot of interests along with development of telecommunication networks. Because the blind equalization or deconvolution is a general framework of the inverse problem, the reliable and faster algorithm is requested in many applications. This paper proposes an orthogonal wavelet transform domain realization of a blind equalization technique termed as EVA, and presents an application to speech analysis. An orthogonal transformation has no influence to the equalization result in general, but we show that a particular wavelet makes the matrix in EVA nearly lower triangular that promotes the faster convergence in the estimation of maximum eigenvalue and its associate vector in EVA iteration. The experiments with the Japanese vowels show that the the proposed method effectively separates the glottis and vocal tract information, hence is promising for speech analysis.

  • Observation of Self-Pulsation Phenomenon in a Semiconductor Ring Laser

    Kozo TAGUCHI  Kaname FUKUSHIMA  Atsuyuki ISHITANI  Masahiro IKEDA  

     
    LETTER-Opto-Electronics

      Vol:
    E82-C No:4
      Page(s):
    659-661

    We first demonstrate a self-pulsation phenomenon in a semiconductor ring laser(SRL). Not only self-mode-locked optical pulse but self-Q-switched optical pulse can be observed in a SRL. Furthermore, experimental results show that the repetition period of the Q-switched optical pulse train can be controlled by the injection current to a SRL.

  • Effect of 300 mm Wafer Transition and Test Processing Logistics on VLSI Manufacturing Final Test Process Efficiency and Cost

    Akihisa CHIKAMURA  Koji NAKAMAE  Hiromu FUJIOKA  

     
    PAPER-Integrated Electronics

      Vol:
    E82-C No:4
      Page(s):
    638-645

    The effect of lot size change and test processing logistics on VLSI manufacturing final test process efficiency and cost due to the transition of from conventional 5 or 6 inches to 300 mm (12 inches) in wafer size is evaluated through simulation analysis. Simulated results show that a high test efficiency and a low test cost are maintained regardless of arrival lot size in the range of the number of 300 mm wafers per lot from 1 to 25 and the content of express lots in the range of up to 50% by using WEIGHT+RPM rule and the right final test processing logistics. WEIGHT+RPM rule is the rule that considers the jig and temperature exchanging time, the lot waiting time in queue and also the remaining processing time of the machine in use. The logistics has a small processing and moving lot size equal to the batch size of testing equipment.

  • 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.

  • Data Transfer Evaluation of Nomadic Data Consistency Model for Large-Scale Mobile Systems

    Masahiro KURODA  Ryoji ONO  Yoshiki SHIMOTSUMA  Takashi WATANABE  Tadanori MIZUNO  

     
    PAPER

      Vol:
    E82-D No:4
      Page(s):
    822-830

    The optimistic consistency scheme has been established with respect to data consistency and availability in distributed systems. The nomadic data consistency model using version vectors to support data versioning for data synchronization and concurrent conflict detection is suitable for an optimistic replication system that supports large-scale wireless networks. This paper describes the architecture and its data consistency model using data versioning and its access domain control targeted for nomadic data sharing systems, such as collaborative works using database and messaging, and the data transfer optimizations of the model. We evaluate our data versioning scheme comparing with a traditional data versioning and the data transfer optimization by estimation and measurement assuming a mobile worker's job. We generate arithmetic formulas for data transfer estimation using the optimizing techniques and apply them to large-scale data sharing configurations in which collaboration groups are dynamically formed and data is exchanged in each group. The data versioning with an access domain increases flexibility in data sharing configurations, such as mobile collaboration systems and client/server type mobile systems. We confirmed that the combination of the general optimizations and the access domain configurations based on our data consistency model is applicable for large-scale mobile data sharing systems.

  • Optimum Design of N Sheet Capacitive Jaumann Absorber Using Genetic Algorithm

    Ahmad CHELDAVI  

     
    LETTER-Numerical Analysis and Optimization

      Vol:
    E82-A No:4
      Page(s):
    704-706

    An optimun design for N(arbitrary)-sheet capacitive Jaumann elctromagnetic (EM) wave absorber, using genetic algorithm will be presented. This algorithm is a random optimization method based on the genetic relation in the human being. We show the bandwidth for two-sheet capacitive Jaumann absorber can be expanded even more than 108% showed by knott, by using this algorithm and without imposing the double-notch design criteria. We also show that our results approaches knott's results when we restrict the characteristic impedances and lengths of the lines to vary within a very short range. We also design one-sheet and three-sheet capacitive Jaumann absorbers. The only restriction used here is about the meaningful range for the design variables. The goal of this algorithm is that we can impose arbitrary restriction about the range of the variation of the variables. So we can see the performance behaviour with the range dimension of the variables, and we can obtain different optimum results for different ranges. Finally we obtain a 20-dB attenuation bandwidth more than 145% for one-sheet, 173% for two-sheet (compare with 108% obtained in [1]) and 193% for three-sheet capacitive Jaumann EM absorbers, with some acceptable short range for the variables. We design the one-sheet and two-sheet capacitive Jaumann absorbers at low frequency and the three-sheet at high frequency. The 20-dB attenuation bandwidth obtained for the one-sheet and two-sheet capacitive Jaumann absorbers are respectively, from 10 to 77 MHz and, from 4 to 61 MHz. For the three-sheet capacitive Jaumann absorber the 20-dB attenuation bandwidth obtained is, from 0.8 GHz to 280 GHz.

  • A Complete Methodology for Electro-Mechanical Characterization of a CMOS Compatible MEMS Technology

    Laurent LATORRE  Pascal NOUET  

     
    PAPER

      Vol:
    E82-C No:4
      Page(s):
    582-588

    In this paper we present a complete methodology for efficient electro-mechanical characterization of a CMOS compatible MEMS technology. Using an original test structure, the so-called "U-shape cantilever beam," we are able to determine all mechanical characteristics of force sensors constituted with elementary beams in a given technology. A complete set of electro-mechanical relations for the design of Microsystems have also been developed.

  • Predictive Fuzzy Logic Control of ABR Traffic in ATM Networks

    Seok-Yong OH  Dong-Jo PARK  

     
    LETTER-Communication Networks and Services

      Vol:
    E82-B No:3
      Page(s):
    551-555

    In this paper, we propose an efficient and stable algorithm employing fuzzy logic for available bit rate (ABR) traffic. Large time-delay incurred in the feedback path and the statistical variation in the link capacity at the ATM node can cause instability or unfairness. The stability and fairness issues are discussed and the performance of the proposed mechanism is evaluated.

  • Partial Order Reduction in Symbolic State Space Traversal Using ZBDDs

    Minoru TOMISAKA  Tomohiro YONEDA  

     
    LETTER-Fault Tolerant Computing

      Vol:
    E82-D No:3
      Page(s):
    704-711

    In order to reduce state explosion problem, techniques such as symbolic state space traversal and partial order reduction have been proposed. Combining these two techniques, however, seems difficult, and only a few research projects related to this topic have been reported. In this paper, we propose handling single place zero reachability problem of Petri nets by using both partial order reduction and symbolic state space traversal based on ZBDDs. We also show experimental results of several examples.

  • 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.

  • Classified Vector Quantization for Image Compression Using Direction Classification

    Chou-Chen WANG  Chin-Hsing CHEN  

     
    PAPER-Image Theory

      Vol:
    E82-A No:3
      Page(s):
    535-542

    In this paper, a classified vector quantization (CVQ) method using a novel direction based classifier is proposed. The new classifier uses a distortion measure related to the angle between vectors to determine the similarity of vectors. The distortion measure is simple and adequate to classify various edge types other than single and straight line types, which limit the size of image block to a rather small size. Simulation results show that the proposed technique can achieve better perceptual quality and edge integrity at a larger block size, as compared to other CVQs. It is shown when the vector dimension is changed from 16(4 4) to 64(8 8), the average bit rate can be reduced from 0. 684 bpp to 0.191, whereas the PSNR degradation is only about 1.2 dB.

  • Speedup of Frequency Switching Time in PLL Frequency Synthesizers Using a Target Frequency Detector

    Shigeki OBOTE  Yasuaki SUMI  Naoki KITAI  Kouichi SYOUBU  Yutaka FUKUI  Yoshio ITOH  

     
    PAPER

      Vol:
    E82-A No:3
      Page(s):
    436-441

    In this paper, we propose a speedup method of frequency switching time in the phase locked loop (PLL) frequency synthesizer using the target frequency detector (TFD). The TFD detects the time Ta for any channels where the output of the PLL frequency synthesizer reaches the target frequency for the first time. At Ta, the programmable divider, the reference divider and the phase comparator are reset, and the phase of the PLL frequency synthesizer is initialized and the phase synchronization is achieved. In the proposed method, since the ringing in the transient state does not occur, the output of the PLL frequency synthesizer converges to the target frequency at Ta and the frequency switching time is speeded up. The effectiveness of the proposed method will be confirmed by experimental results.

  • PLL Frequency Synthesizer with Multi-Phase Detector

    Yasuaki SUMI  Kouichi SYOUBU  Shigeki OBOTE  Yutaka FUKUI  Yoshio ITOH  

     
    PAPER

      Vol:
    E82-A No:3
      Page(s):
    431-435

    The lock-up time of a PLL frequency synthesizer mainly depends on the total loop gain. Since the gain of the conventional phase detector is constant, it is difficult to improve the lock-up time by the phase detector. In this paper, we reconsider the operation of the phase detector and propose the PLL frequency synthesizer with multi-phase detector in which the gain of phase detector is increased by using four stage phase detectors and charge pumps. Then, a higher speed lock-up time and good spurious characteristics can be achieved.

  • Deriving Concurrent Synchronous EFSMs from Protocol Specifications in LOTOS

    Akira KITAJIMA  Keiichi YASUMOTO  Teruo HIGASHINO  Kenichi TANIGUCHI  

     
    PAPER

      Vol:
    E82-A No:3
      Page(s):
    487-494

    In this paper, we propose an algorithm to convert a given structured LOTOS specification into an equivalent flattened model called synchronous EFSMs. The synchronous EFSMs model is an execution model for communication protocols and distributed systems where each system consists of concurrent EFSMs and a finite set of multi-rendezvous indications among their subsets. The EFSMs can be derived from a specification in a sub-class of LOTOS and its implementation becomes simpler than the straightforward implementation of the original LOTOS specification because the synchronization among the processes in the model does not have any child-parent relationships, which can make the synchronization mechanism much more complex. Some experimental results are reported to show the advantage of synchronous EFSMs in terms of execution efficiency.

  • DEMI: A Delay Minimization Algorithm for Cell-Based Digital VLSI Design

    Tae Hoon KIM  Young Hwan KIM  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E82-A No:3
      Page(s):
    504-511

    This paper presents a heuristic algorithm that minimizes the delay of the given circuit through a two-pass cell selection in cell-based design. First, we introduce a new graph, called candidate web, which conveniently represents all cell combinations available for the implementation of the given circuit. We, then, present an efficient method to obtain a tentative set of optimal cells, while estimating the delay of the longest path between each cell and the primary output on the candidate web. In this step, multiple cells are allowed to bind the same logic gate. Finally, we describe how the proposed approach actually selects the optimal cells from the tentative set, which would minimize the circuit delay. Experimental results on a set of benchmarks show that the proposed approach is effective and efficient in minimizing the delay of the given circuit.

  • The Family of Regularized Parametric Projection Filters for Digital Image Restoration

    Hideyuki IMAI  Akira TANAKA  Masaaki MIYAKOSHI  

     
    PAPER-Image Theory

      Vol:
    E82-A No:3
      Page(s):
    527-534

    Optimum filters for an image restoration are formed by a degradation operator, a covariance operator of original images, and one of noise. However, in a practical image restoration problem, the degradation operator and the covariance operators are estimated on the basis of empirical knowledge. Thus, it appears that they differ from the true ones. When we restore a degraded image by an optimum filter belonging to the family of Projection Filters and Parametric Projection Filters, it is shown that small deviations in the degradation operator and the covariance matrix can cause a large deviation in a restored image. In this paper, we propose new optimum filters based on the regularization method called the family of Regularized Projection Filters, and show that they are stable to deviations in operators. Moreover, some numerical examples follow to confirm that our description is valid.

5001-5020hit(5900hit)