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[Keyword] TE(21534hit)

12461-12480hit(21534hit)

  • A New Low Power Test Pattern Generator for BIST Architecture

    Kicheol KIM  Dongsub SONG  Incheol KIM  Sungho KANG  

     
    LETTER-Semiconductor Materials and Devices

      Vol:
    E88-C No:10
      Page(s):
    2037-2038

    A new low power test pattern generator (TPG) which can effectively reduce the average power consumption during test application is developed. The new TPG reduces the weighted switching activity (WSA) of the circuit under test (CUT) by suppressing transitions at some primary inputs which make many transitions. Moreover, the new TPG does not lose fault coverage. Experimental results on the ISCAS benchmark circuits show that average power reduction can be achieved up to 33.8% while achieving high fault coverage.

  • Rules and Algorithms for Phonetic Transcription of Standard Malay

    Yousif A. EL-IMAM  Zuraidah Mohd DON  

     
    PAPER-Speech and Hearing

      Vol:
    E88-D No:10
      Page(s):
    2354-2372

    Phonetic transcription of text is an indispensable component of text-to-speech (TTS) systems and is used in acoustic modeling for speech recognition and other natural language processing applications. One approach to the transcription of written text into phonetic entities or sounds is to use a set of well-defined context and language-dependent rules. The process of transcribing text into sounds starts by preprocessing the text and representing it by lexical items to which the rules are applicable. The rules can be segregated into phonemic and phonetic rules. Phonemic rules operate on graphemes to convert them into phonemes. Phonetic rules operate on phonemes and convert them into context-dependent phonetic entities with actual sounds. Converting from written text into actual sounds, developing a comprehensive set of rules, and transforming the rules into implementable algorithms for any language cause several problems that have their origins in the relative lack of correspondence between the spelling of the lexical items and their sound contents. For Standard Malay (SM) these problems are not as severe as those for languages of complex spelling systems, such as English and French, but they do exist. In this paper, developing a comprehensive computerized system for processing SM text and transcribing it into phonetic entities and evaluating the performance of this system, irrespective of the application, is discussed. In particular, the following issues are dealt with in this paper: (1) the spelling and other problems of SM writing and their impact on converting graphemes into phonemes, (2) the development of a comprehensive set of grapheme-to-phoneme rules for SM, (3) a description of the phonetic variations of SM or how the phonemes of SM vary in context and the development of a set of phoneme-to-phonetic transcription rules, (4) the formulation of the phonemic and phonetic rules into algorithms that are applicable to the computer-based processing of input SM text, and (5) the evaluation of the performance of the process of converting SM text into actual sounds by the above mentioned methods.

  • Space-Time Domain Optimization of Transmitter Weights in Closed-Loop Transmit Antenna Diversity

    Ye Hoon LEE  Nam-Soo KIM  Seung Young PARK  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E88-B No:10
      Page(s):
    4121-4124

    The optimal antenna weighting scheme that minimizes the average bit error rate in a closed-loop transmit antenna diversity system is investigated under the assumption that channel state information is provided at both the transmitter and the receiver. A closed-form expression for the optimal transmitter weights is derived with a fixed average transmit power constraint. Also, the effect of limited peak transmit power on the performance of the optimal weighting method is analyzed. Base on this analysis, it is shown that the proposed transmitter weights yield significant performance improvements over the conventional weights on the wide range of practical system parameters.

  • Texture Classification Using Hierarchical Linear Discriminant Space

    Yousun KANG  Ken'ichi MOROOKA  Hiroshi NAGAHASHI  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E88-D No:10
      Page(s):
    2380-2388

    As a representative of the linear discriminant analysis, the Fisher method is most widely used in practice and it is very effective in two-class classification. However, when it is expanded to a multi-class classification problem, the precision of its discrimination may become worse. A main reason is an occurrence of overlapped distributions on the discriminant space built by Fisher criterion. In order to take such overlaps among classes into consideration, our approach builds a new discriminant space by hierarchically classifying the overlapped classes. In this paper, we propose a new hierarchical discriminant analysis for texture classification. We divide the discriminant space into subspaces by recursively grouping the overlapped classes. In the experiment, texture images from many classes are classified based on the proposed method. We show the outstanding result compared with the conventional Fisher method.

  • A Distributed Route Computation Method to Promote Bandwidth Sharing between Backup Lightpaths

    Nagao OGINO  Hideaki TANAKA  

     
    PAPER

      Vol:
    E88-B No:10
      Page(s):
    3930-3940

    The optical network is a promising approach for realizing a scalable backbone network. In backbone networks, survivability is very important because great volumes of traffic incur damage from faulty equipment. To address this issue, various recovery schemes have been proposed for optical backbone networks. Among those schemes, shared mesh restoration utilizes link bandwidth efficiently because the backup lightpaths share link bandwidth if they protect against different failures and are never utilized simultaneously. However, a route computation method for the backup lightpaths that promotes such bandwidth sharing is necessary to achieve efficient bandwidth utilization. This paper proposes a distributed route computation method for the backup lightpaths in shared mesh restoration. In this method, the link weight is estimated to be smaller if a backup lightpath newly established can share the link bandwidth with the backup lightpaths already accommodated in that link. The link weight can be calculated using the Markov Decision Theory. The bandwidth sharing between the backup lightpaths can be promoted by selecting the shortest route based on such modified link weights. The proposed method effectively realizes efficient utilization of the link bandwidth and achieves low loss rate of reliable lightpath establishment requests under the same traffic load. The proposed method restricts the amount of link state information advertised by the routing protocol and achieves a sufficiently small amount of route calculation.

  • Semi-Dynamic Protection Path Configuration for Hybrid Optical Cross-Connect Networks

    Hoyoung HWANG  

     
    PAPER

      Vol:
    E88-B No:10
      Page(s):
    3922-3929

    In this paper, a semi-dynamic protection path configuration method is proposed for WDM optical networks. In the method, the protection path is established by connecting several sub-lightpaths from the source node to the destination node of the original working lightpath, as opposed to conventional path restoration method where a single protection lightpath between the source-destination pair performs restoration. The proposed method provides enhanced flexibility in protection path configuration and relieves the cost of spare capacity reservation. This paper also studies the effects of wavelength conversion capability of intermediate optical cross-connect nodes on protection path routing and spare capacity utilization. In terms of spare capacity utilization, the proposed method shows substantial reduction of spare capacity overhead compared with dedicated path restoration in all optical networks without wavelength conversion, and shows similar capacity efficiency compared with shared path restoration in opaque networks with full wavelength conversion capability. In terms of robustness, the proposed method shows nearly the same restoration ratio for double-link failure as that of dynamic restoration method.

  • Proposal and Comparison of QoS Schemes for IP-over-Optical Multilayer Networks

    Takumi KIMURA  Keisuke KABASHIMA  Michihiro AOKI  Shigeo URUSHIDANI  

     
    PAPER

      Vol:
    E88-B No:10
      Page(s):
    3895-3903

    IP-over-optical multilayer networks are capable of flexibly dealing with traffic increases and fluctuations because they support both high-speed transmission using lightpaths and scalable IP hop-by-hop transmission. This paper introduces an architecture for quality of service (QoS) control in such networks, based on the differentiated services (DiffServ) concept. The architecture supports both class-based queues and class-based lightpaths to efficiently handle multiple-QoS-class traffic. QoS schemes based on the proposed architecture are categorized into four types according to their traffic-differentiation and transmission mechanisms. Through simulation, the schemes are evaluated in terms of measures that largely determines network costs. Finally, the conditions under which each scheme is feasible are clarified in terms of the traffic volume and the cost of class-based queues for DiffServ.

  • Design of Extremum Seeking Control with Accelerator

    Hitoshi TAKATA  Tomohiro HACHINO  Ryuichiro TAMURA  Kazuo KOMATSU  

     
    PAPER

      Vol:
    E88-A No:10
      Page(s):
    2535-2540

    In this paper we are concerned with designing an extremum seeking control law for nonlinear systems. This is a modification of a standard extremum seeking controller. It is equipped with an accelerator to the original one aimed at achieving the maximum operating point more rapidly. This accelerator is designed by making use of a polynomial identification of an uncertain output map, the Butterworth filter to smoothen the control, and analog-digital converters. Numerical experiments show how this modified approach can be well in control of the Monod model of bioreactors.

  • Query Learning Method for Character Recognition Methods Using Genetic Algorithm

    Hitoshi SAKANO  

     
    LETTER

      Vol:
    E88-D No:10
      Page(s):
    2313-2316

    We propose a learning method combining query learning and a "genetic translator" we previously developed. Query learning is a useful technique for high-accuracy, high-speed learning and reduction of training sample size. However, it has not been applied to practical optical character readers (OCRs) because human beings cannot recognize queries as character images in the feature space used in practical OCR devices. We previously proposed a character image reconstruction method using a genetic algorithm. This method is applied as a "translator" from feature space for query learning of character recognition. The results of an experiment with hand-written numeral recognition show the possibility of training sample size reduction.

  • Structure Selection and Identification of Hammerstein Type Nonlinear Systems Using Automatic Choosing Function Model and Genetic Algorithm

    Tomohiro HACHINO  Hitoshi TAKATA  

     
    PAPER

      Vol:
    E88-A No:10
      Page(s):
    2541-2547

    This paper presents a novel method of structure selection and identification for Hammerstein type nonlinear systems. An unknown nonlinear static part to be estimated is approximately represented by an automatic choosing function (ACF) model. The connection coefficients of the ACF and the system parameters of the linear dynamic part are estimated by the linear least-squares method. The adjusting parameters for the ACF model structure, i.e. the number and widths of the subdomains and the shape of the ACF are properly selected by using a genetic algorithm, in which the Akaike information criterion is utilized as the fitness value function. The effectiveness of the proposed method is confirmed through numerical experiments.

  • A Novel Model for Computing the Effective Capacitance of CMOS Gates with Interconnect Loads

    Zhangcai HUANG  Atsushi KUROKAWA  Yasuaki INOUE  Junfa MAO  

     
    PAPER

      Vol:
    E88-A No:10
      Page(s):
    2562-2569

    In deep submicron designs, the interconnect wires play a major role in the timing behavior of logic gates. The effective capacitance Ceff concept is usually used to calculate the delay of gate with interconnect loads. In this paper, we present a new method of Integration Approximation to calculate Ceff. In this new method, the complicated nonlinear gate output is assumed as a piecewise linear (PWL) waveform. A new model is then derived to compute the value of Ceff. The introduction of Integration Approximation results in Ceff being insensitive to output waveform shape. Therefore, the new method can be applied to various output waveforms of CMOS gates with RC-π loads. Experimental results show a significant improvement in accuracy.

  • The Adaptive Distributed Source Coding of Multi-View Images in Camera Sensor Networks

    Mehrdad PANAHPOUR TEHRANI  Toshiaki FUJII  Masayuki TANIMOTO  

     
    PAPER-Image Coding

      Vol:
    E88-A No:10
      Page(s):
    2835-2843

    We show that distributed source coding of multi-view images in camera sensor networks (CSNs) using adaptive modules can come close to the Slepian-Wolf bound. In a systematic scenario with limited node abilities, work by Slepian and Wolf suggest that it is possible to encode statistically dependent signals in a distributed manner to the same rate as with a system where the signals are jointly encoded. We considered three nodes (PN, CN and CNs), which are statistically depended. Different distributed architecture solutions are proposed based on a parent node and child node framework. A PN sends the whole image whereas a CNs/CN only partially, using an adaptive coding based on adaptive module-operation at a rate close to theoretical bound - H(CNs|PN)/H(CN|PN,CNs). CNs sends sub-sampled image and encodes the rest of image, however CN encodes all image. In other words, the proposed scheme allows independent encoding and jointly decoding of views. Experimental results show performance close to the information-theoretic limit. Furthermore, good performance of the proposed architecture with adaptive scheme shows significant improvement over previous work.

  • Priority-Based Optimized Bandwidth Reservation for Efficient Differentiated Services in Ethernet-PON

    NamUk KIM  Minho KANG  

     
    PAPER

      Vol:
    E88-B No:10
      Page(s):
    3962-3970

    In this paper, we address how to efficiently support differentiated services with the optimized bandwidth reservation in a polling-based generalized TDMA network like E-PON (Ethernet Passive Optical Network). In E-PON, performances of service differentiation for QoS (Quality of Service) guaranteed multiples services are directly affected by the bandwidth reservation algorithm of ONU (Optical Network Unit) in addition to the priority-based packet scheduling. Our proposed Service Quality Pre-engagement (SQP) algorithm reduces the system buffer size, the light-load penalty problem and the service interference among classes effectively by partially introducing the dynamic forward recurrence reservation scheme for QoS guaranteed classes. We also introduce the FRC(Forward Reservation Class) Selection algorithm that preserves the optimized reservation bandwidth to minimize the unnecessary reservation contentions. These algorithms do not mandate the basic concept of DBA and request the similar amount of REPORT bandwidth. The analytic and simulation results are performed to evaluate the performances of the proposed algorithms.

  • Signal Mappings of 8-Ary Constellations for BICM-ID Systems over a Rayleigh Fading Channel

    Nghi H. TRAN  Ha H. NGUYEN  

     
    LETTER-Fundamental Theories for Communications

      Vol:
    E88-B No:10
      Page(s):
    4083-4086

    It is known that in a bit-interleaved coded-modulation with iterative decoding (BICM-ID), signal constellation and mapping strongly influence the system's error performance. This letter presents good mappings of various 8-ary constellations for BICM-ID systems operating over a frequency non-selective block Rayleigh fading channel. Simulation results for the error performance of different constellations/mappings are also provided and discussed.

  • Analysis of Bit Error Probability of Trellis Coded 8-PSK

    Hideki YOSHIKAWA  

     
    LETTER-Communication Theory

      Vol:
    E88-A No:10
      Page(s):
    2956-2959

    The letter presents an analysis of bit error probability for trellis coded 8-ary phase shift keying moduation with 2-state soft decision Viterbi decoding. It is shown that exact numerical error performance can be obtained for low singal-to-noise power ratio where bounds are useless.

  • A Burst-Switched Photonic Network Testbed: Its Architecture, Protocols and Experiments

    Yongmei SUN  Tomohiro HASHIGUCHI  Vu Quang MINH  Xi WANG  Hiroyuki MORIKAWA  Tomonori AOYAMA  

     
    PAPER

      Vol:
    E88-B No:10
      Page(s):
    3864-3873

    In the future network, optical technology will play a stronger role not only for transmission but also for switching. Optical burst switching (OBS) emerged as a promising switching paradigm. It brings together the complementary strengths of optics and electronics. This paper presents the design and implementation of an overlay mode burst-switched photonic network testbed, including its architecture, protocols, algorithms and experiments. We propose a flexible "transceiver + forwarding" OBS node architecture to perform both electronic burst assembly/disassembly and optical burst forwarding. It has been designed to provide class of service (CoS), wavelength selection for local bursts, and transparency to cut-through bursts. The functional modules of OBS control plane and its key design issues are presented, including signaling, routing, and a novel scheduling mechanism with combined contention resolution in space and wavelength domains. Finally, we report the experimental results on functional verification, performance analysis and service demonstration.

  • Properties of Role-Based Access Control in a Teaching Management System

    Kazushi TANIHIRA  Hiromi KOBAYASHI  

     
    LETTER-Educational Technology

      Vol:
    E88-D No:10
      Page(s):
    2417-2421

    This paper presents properties of role-based access control which were obtained through a development of a prototype of a teaching management system. These properties are related to assignment of temporal constraints and access control procedure in terms of the corresponding flow of user's view and considered to be suitable to other information systems.

  • Real Time Search for Similar Hand Images from Database for Robotic Hand Control

    Kiyoshi HOSHINO  Takanobu TANIMOTO  

     
    PAPER

      Vol:
    E88-A No:10
      Page(s):
    2514-2520

    The authors propose a system for searching the shape of human hands and fingers in real time and with high accuracy, without using any special peripheral equipment such as range sensor, PC cluster, etc., by a method of retrieving similar image quickly with high accuracy from a large volume of image database containing the complicated shapes and self-occlusions. In designing the system, we constructed a database in a way to be adaptable even to differences among individuals, and searched CG images of hand similar to unknown hand image, through extraction of characteristics using high-order local autocorrelational patterns, reduction of the amount of characteristics centering on principal component analysis, and prior rearrangement of data corresponding to the amount of characteristics. As a result of experiments, our system performed high-accuracy estimation of human hand shape where mean error was 7 degrees in finger joint angles, with the processing speed of 30 fps or over.

  • An SDMA Approach with Preamble Subcarrier Assignment for IEEE802.11a-Based OFDM Signals

    Yunjian JIA  Shinsuke HARA  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E88-B No:10
      Page(s):
    4133-4137

    In this letter, we present a space division multiple access (SDMA) approach for IEEE802.11a-based system employing pre-fast Fourier transform (FFT) adaptive array antenna (AAA) at base station (BS). As the core idea, we propose a preamble subcarrier assignment method to generate different preambles for different users using the same signal burst structure defined by IEEE802.11a, by which BS can effectively distinguish each user from other users and accurately estimate the channel impulse response (CIR) for each user. In this way, SDMA can be easily realized with no significant change in IEEE802.11a-based system. The performance of the proposed SDMA system is evaluated by computer simulation using a realistic spatio-temporal indoor wireless channel model.

  • Progressive Image Inpainting Based on Wavelet Transform

    Yen-Liang CHEN  Ching-Tang HSIEH  Chih-Hsu HSU  

     
    PAPER-Image Coding

      Vol:
    E88-A No:10
      Page(s):
    2826-2834

    Currently, the automatic image inpainting methods emphasize the inpainting techniques either globally or locally. They didn't consider the merits of global and local techniques to compensate each other. On the contrary, the artists fixed an image in global view firstly, and then focus on the local features of it, when they repaired it. This paper proposes a progressive processing of image inpainting method based on multi-resolution analysis. In damaged and defective area, we imitate the artistic techniques to approach the effectiveness of image inpainting in human vision. First, we use the multi-resolution characteristics of wavelet transform, from the lowest spatial-frequency layer to the higher one, to analyze the image from global-area to local-area progressively. Then, we utilize the variance of the energy of wavelet coefficients within each image block, to decide the priority of inpainting blocks. Finally, we extract the multi-resolution features of each block. We take account of the correlation among horizontal, vertical and diagonal directions, to determine the inpainting strategy for filling image pixels and approximate a high-quality image inpainting to human vision. In our experiments, the performance of the proposed method is superior to the existing methods.

12461-12480hit(21534hit)