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[Keyword] SC(4570hit)

2961-2980hit(4570hit)

  • A Gm-C Filter Using Multiple-Output Linearized Transconductors

    Tadashi ARAI  Tetsuro ITAKURA  

     
    PAPER

      Vol:
    E87-A No:2
      Page(s):
    384-389

    A Gm-C filter using multiple-output transconductors suitable for reducing the chip area and power consumption is presented. The novel multiple-output transconductor is based on a translinear gain cell with a linearized input stage. Making good use of the linearized input stage, a simple common-mode feedback is also proposed for this multiple-output transconductor. Using the proposed technique, a 5th-order lowpass filter with two transmission zeros was designed and fabricated as a main part of a lowpass channel selection filter for UMTS receivers. A channel of the filter consumes 7 mA from a 2.7 V power supply and the integrated input-referred noise was 21 dBuV with 20 dB pass band gain. The proposed multiple-output technique saves roughly half the number of transconductors compared with the typical active ladder filter design. The proposed multiple-output transconductors achieve linearization and effective reduction while saving linearized input stages. They are suitable for a filter with small power consumption and small area.

  • Schema Co-Evolutionary Algorithm (SCEA)

    Kwee-Bo SIM  Dong-Wook LEE  

     
    PAPER-Algorithms

      Vol:
    E87-D No:2
      Page(s):
    416-425

    Simple genetic algorithm (SGA) is a population-based optimization method based on the Darwinian natural selection. The theoretical foundations of SGA are the Schema Theorem and the Building Block Hypothesis. Although SGA does well in many applications as an optimization method, it still does not guarantee the convergence of a global optimum in GA-hard problems and deceptive problems. As an alternative schema, therefore, there is a growing interest in a co-evolutionary system where two populations constantly interact and cooperate each other. In this paper we propose a schema co-evolutionary algorithm (SCEA) and show why the SCEA works better than SGA in terms of an extended schema theorem. The experimental analyses using the Walsh-Schema Transform show that the SCEA works well in GA-hard problems including deceptive problems.

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

    Kazuo HORIUCHI  

     
    LETTER-Nonlinear Problems

      Vol:
    E87-A No:2
      Page(s):
    509-510

    A mathematical theory is proposed based on the concept of functional analysis, suitable for operation of network systems extraordinarily complicated and diversified on large scales, through connected-block structures. Fundamental conditions for existence and evaluation of system behaviors of such network systems are obtained in a form of fixed point theorem for system of nonlinear mappings.

  • Optical Fiber Bio-Sensor Using Adsorption LB Films

    Kazuhiro KUDO  

     
    LETTER-Nano-interface Controlled Electronic Devices

      Vol:
    E87-C No:2
      Page(s):
    185-187

    An optical fiber biosensor using adsorption LB films has been investigated for the application to the glucose detection in blood. The adsorption LB film containing glucose oxidase (GOD: the enzyme in human body) was deposited on the core portion of optical fiber and the variation of absorption spectra due to the reactions of GOD, glucose, and hemoglobin was measured. The relatively high response time of 60 s and glucose sensitivity as low as 20 mg/dl were obtained. The results demonstrate that the optical fiber bio-sensor using adsorption LB film can be used as a glucose sensor.

  • Doping Effects on the Series Resistance of Conducting Polymers Diode

    Masayuki WADA  Kazuya TADA  Mitsuyoshi ONODA  

     
    PAPER-Nano-interfacial Properties

      Vol:
    E87-C No:2
      Page(s):
    152-157

    A device structure for polymer Schottky diode, which has the glass chimney as a dopant reservoir enabling the reduction of series resistance without cathode corrosion, has been proposed. Doping with the acetonitrile solution of FeCl3 in the device resulted in the increase in the forward-bias current by one order of magnitude without notable increase in reverse-bias current, suggesting that the doping reduced the series resistance. It is found that the penetration speed depends on the solvents. Short time doping with the nitromethane solution of FeCl3 resulted in the increase by three orders of magnitude. However, doping for a long period yielded the considerable increase in the reverse-bias current due to the complete penetration of dopatn solution. When the upper opening of glass chimney of device is left opened and the sample after doping stored in air, the forward-bias current of the device reduced rapidly due to the undoping and/or degradation of polymer. It is possible to protect the degradation of device characteristics after doping, by sealing the chimney and storing the device in vacuum.

  • On Robust Approximate Feedback Linearization

    Ho-Lim CHOI  Jong-Tae LIM  

     
    LETTER-Systems and Control

      Vol:
    E87-A No:2
      Page(s):
    502-504

    In this paper, we consider a problem of global stabilization of a class of nonlinear systems which are approximately feedback linearizable. We propose a control law with the gain-scaling factor and analytically show the robust aspect of approximate feedback linearization in a more general framework.

  • Scattering of an Electromagnetic Plane Wave by a Plane with Local Change of Surface Impedance

    Michinari SHIMODA  Ryuichi IWAKI  Masazumi MIYOSHI  

     
    PAPER-Electromagnetic Theory

      Vol:
    E87-C No:1
      Page(s):
    44-51

    The electromagnetic scattering of a plane wave by an inhomogeneous plane whose surface impedance changes locally on the plane is treated. A boundary-value problem is formulated to describe the scattering phenomenon, in which the boundary condition depends on the surface impedance of the plane. Application of the Fourier transform derives an integral equation, which is approximately solved by the method of least-squares. From the solution of the equation, the scattered field is obtained by the inverse Fourier transform. By the use of the incomplete Lipschitz-Hankel integral for the computation of the field, numerical examples are given and the scattering phenomenon is discussed.

  • VLSI Architecture for 2-D 3-Level Lifting-Based Discrete Wavelet Transform

    Pei-Yin CHEN  

     
    LETTER-VLSI Design Technology and CAD

      Vol:
    E87-A No:1
      Page(s):
    275-279

    Discrete wavelet transform has been successfully used in many image processing applications. In this paper, we present an efficient VLSI architecture for 2-D 3-level lifting-based discrete wavelet transform using the (5, 3) filter. All three-level coefficients are computed interlacingly and periodically to achieve higher hardware utilization and better throughput. In comparison with other VLSI architectures, our architecture requires less size of storage and faster computation speed.

  • Medium Starting Potential Fair Queueing for High-Speed Networks

    Dong-Yong KWAK  Nam-Seok KO  Hong-Shik PARK  

     
    LETTER-Network

      Vol:
    E87-B No:1
      Page(s):
    188-191

    This paper proposes an efficient fair queuing algorithm, called Medium Starting Potential Fair Queuing (MSPFQ), which has O(1) complexity for the virtual time computation while it has delay and fairness properties similar to Starting-Potential Fair Queueing (SPFQ). The key idea of MSPFQ algorithm is that it recalibrates the system virtual time to the medium value of the minimum possible virtual start times of HOL packets in each backlogged session. We show that MSPFQ belongs to the class of Rate-Proportional Server (RPS). In addition, we analytically prove that our algorithm has good delay and fairness properties.

  • Robust Extended Kalman Filtering via Krein Space Estimation

    Tae Hoon LEE  Won Sang RA  Seung Hee JIN  Tae Sung YOON  Jin Bae PARK  

     
    PAPER-Systems and Control

      Vol:
    E87-A No:1
      Page(s):
    243-250

    A new robust extended Kalman filter is proposed for the discrete-time nonlinear systems with norm-bounded parameter uncertainties. After linearization of the nonlinear systems, the uncertainties described by the energy bounded constraint can be converted into an indefinite quadratic cost function to be minimized. The solution to the minimization problem is given by the extended Kalman filter derived in a Krein space, which leads to a robust version of the extended Kalman filter. Since the resulting robust filter has the same structure as a standard extended Kalman filter, the proposed filter can be readily designed by simply including the uncertainty terms in its formulas. The results of simulations are presented to demonstrate that the proposed filter achieves the robustness against parameter variation and performs better than the standard extended Kalman filter.

  • Global Open Ethernet Architecture for a Cost-Effective Scalable VPN Solution

    Atsushi IWATA  Youichi HIDAKA  Masaki UMAYABASHI  Nobuyuki ENOMOTO  Akira ARUTAKI  Kazuo TAKAGI  Dirceu CAVENDISH  Rauf IZMAILOV  

     
    PAPER-Internet

      Vol:
    E87-B No:1
      Page(s):
    142-151

    The authors propose a Global Open Ethernet (GOE) architecture as a cost-effective scalable solution for next generation of VPNs over optical network infrastructure. Three main approaches have been proposed for a cost-effective VPN solution on metro area network (MAN): Resilient Packet Ring (RPR), Ethernet over MPLS (EoMPLS), Extended Ethernet via Stacked VLAN tagging (EESVLAN). None of these schemes can satisfy the following requirements at the same time: network topology flexibility, affordable network functionalities, low equipment cost, and low operational cost. We propose the GOE architecture as an affordable VPN solution that addresses all these requirements. GOE combines the functionality of MPLS VPN with low cost and easy operation of Ethernet-based solutions in a cost-effective scalable manner. In this paper, we evaluate the performance of EoMPLS, EESVLAN and GOE VPN solutions in terms of the cost and network utilization. We show that the cost of GOE solution is two-three times smaller than the cost of the other approaches. We also demonstrate that the network utilization provided by GOE is 22% higher than that of both EoMPLS and EESVLAN. Therefore, GOE can be shown to be a cost-effective simple VPN solution with clear advantages in functionality, management and performance.

  • Bipolar Scan Waveform for Fast Address in AC Plasma Display Panel

    Ki-Duck CHO  Heung-Sik TAE  Sung-Il CHIEN  

     
    LETTER-Electronic Displays

      Vol:
    E87-C No:1
      Page(s):
    116-119

    A new bipolar scan waveform is proposed to increase the light emission duty factor by achieving the fast address in AC plasma display panel (AC-PDP). The new bipolar scan waveform consists of two-step scan pulse, which can separate the address discharge mode into two different discharge modes: a space charge generation mode and a wall charge accumulation mode. By adopting the new bipolar scan waveform, the light emission duty factor is increased considerably under the single scan ADS driving scheme due to the reduction of address time per single subfield.

  • A Cache Replacement Policy for Transcoding Proxy Servers

    Kai-Hau YEUNG  Chun-Cheong WONG  Kin-Yeung WONG  Suk-Yu HUI  

     
    LETTER-Multimedia Systems

      Vol:
    E87-B No:1
      Page(s):
    209-211

    A cache replacement policy which takes the transcoding time into account in making replacement decisions, for the emerging transcoding proxy servers is proposed. Simulation results show the proposed policy outperforms the conventional LRU in both the cache hit rate and the average object transcoding time.

  • Speech Summarization: An Approach through Word Extraction and a Method for Evaluation

    Chiori HORI  Sadaoki FURUI  

     
    PAPER

      Vol:
    E87-D No:1
      Page(s):
    15-25

    In this paper, we propose a new method of automatic speech summarization for each utterance, where a set of words that maximizes a summarization score is extracted from automatic speech transcriptions. The summarization score indicates the appropriateness of summarized sentences. This extraction is achieved by using a dynamic programming technique according to a target summarization ratio. This ratio is the number of characters/words in the summarized sentence divided by the number of characters/words in the original sentence. The extracted set of words is then connected to build a summarized sentence. The summarization score consists of a word significance measure, linguistic likelihood, and a confidence measure. This paper also proposes a new method of measuring summarization accuracy based on a word network expressing manual summarization results. The summarization accuracy of each automatic summarization is calculated by comparing it with the most similar word string in the network. Japanese broadcast-news speech, transcribed using a large-vocabulary continuous-speech recognition (LVCSR) system, is summarized and evaluated using our proposed method with 20, 40, 60, 70 and 80% summarization ratios. Experimental results reveal that the proposed method can effectively extract relatively important information by removing redundant or irrelevant information.

  • 3D Human Whole Body Construction by Contour Triangulation

    Bon-Ki KOO  Young-Kyu CHOI  Sung-Il CHIEN  

     
    PAPER-Computer Graphics

      Vol:
    E87-D No:1
      Page(s):
    233-243

    In the past decade, significant effort has been made toward increasing the accuracy and robustness of three-dimensional scanning methods. In this paper, we present a new prototype vision system named 3D Model Studio, which has been built to reconstruct a complete 3D model in as less as a few minutes. New schemes for a probe calibration and a 3D data merging (axis consolidation) are employed. We also propose a new semi-automatic contour registration method to generate accurate contour model from 3D data points, along with a contour triangulation based surface reconstruction. Experimental result shows that our system works well for reconstructing a complete 3D surface model of a human body.

  • Fast Elliptic Curve Multiplications with SIMD Operations

    Tetsuya IZU  Tsuyoshi TAKAGI  

     
    PAPER-Asymmetric Cipher

      Vol:
    E87-A No:1
      Page(s):
    85-93

    The Single Instruction, Multiple Data (SIMD) architecture enables computation in parallel on a single processor. The SIMD operations are implemented on some processors such as Pentium 3/4, Athlon, SPARC, or even on smart cards. This paper proposes efficient algorithms for assembling an elliptic curve addition (ECADD), doubling (ECDBL), and k-iterated ECDBL (k-ECDBL) with SIMD operations. We optimize the number of auxiliary variables and the order of basic field operations used for these addition formulas. If an addition chain has k-bit zero run, we can replace k-time ECDBLs to the proposed faster k-ECDBL and the total efficiency of the scalar multiplication can be improved. Using the singed binary chain, we can compute a scalar multiplication about 10% faster than the previously fastest algorithm proposed by Aoki et al. Combined with the sliding window method or the width-w NAF window method, we also achieve about 10% faster parallelized scalar multiplication algorithms with SIMD operations. For the implementation on smart cards, we establish two fast parallelized scalar multiplication algorithms with SIMD resistant against side channel attacks.

  • 1-out-of-n Signatures from a Variety of Keys

    Masayuki ABE  Miyako OHKUBO  Koutarou SUZUKI  

     
    PAPER-Asymmetric Cipher

      Vol:
    E87-A No:1
      Page(s):
    131-140

    This paper addresses how to use public-keys of several different signature schemes to generate 1-out-of-n signatures. Previously known constructions are for either RSA-type keys only or DL-type keys only. We present a widely applicable method to construct a 1-out-of-n signature scheme that allows mixture use of different flavors of keys at the same time. The resulting scheme is more efficient than previous schemes even if it is used only with a single type of keys. With all DL-type keys, it yields shorter signatures than the ones of the previously known scheme based on the witness indistinguishable proofs by Cramer, et al. With all RSA-type keys, it reduces both computational and storage costs compared to that of the Ring signatures by Rivest, et al.

  • New Time-Stamping Scheme Using Mutual Communications with Pseudonymous Clients

    Akira YAMADA  Shinsaku KIYOMOTO  Toshiaki TANAKA  Koji NAKAO  

     
    PAPER-Applications

      Vol:
    E87-A No:1
      Page(s):
    182-189

    Linking schemes have been proposed assuming the model where the time-stamp issuer need not be trusted. However, in that environment, a fake chain attack and forward or backward dating attacks are still a residual risk in Time-Stamping services (TSS). In this paper, we propose a new time-stamping scheme that focuses on these problems. In our scheme, we use pseudonyms to prevent the time-stamp issuer from dating the time that the specific entity requests. Our scheme doesn't rely on only one trustworthy entity, and uses mutual communication between each entity. Two types of entities, server and clients without any trustworthy entities are configured in our system. The server provides an anonymous communication channel, but doesn't provide TSS, and the clients are not only time-stamp requesters but also issuers. So, when a client requests a time-stamp from the system, it is issued by one of the other clients.

  • Removing Unnecessary Buffers and Timers in EDF Scheduler with Regulators in Fixed-Sized Packet Networks

    Kihyun PYUN  Junehwa SONG  Heung-Kyu LEE  

     
    LETTER-Network

      Vol:
    E86-B No:12
      Page(s):
    3646-3650

    Among the many scheduling algorithms which can guarantee delay bounds of sessions, the EDF scheduler with regulators has received wide attention since it can admit a very high number of sessions. However, due to regulators, EDF with regulators has difficulty in scalable implementation. To implement a regulator, a buffer and a timer are needed to restrict the incoming traffics. Given N number of sessions, N regulators are required. Moreover, due to regulators, the entire scheduling algorithm is not work-conserving. To enforce work-conserveness, it is known in the literature that additional buffers and a complex mechanism are required to bypass regulators. Thus, scalable implementation becomes much more difficult in the case of the work-conserving EDF with regulators. In this paper, however, we show that the buffers and timers used to implement regulators are unnecessary to guarantee delay bounds of admitted sessions in fixed-sized packet networks. Then, we can remove those unnecessary buffers and timers. By the removal, the resulting scheduling algorithm can be implemented in a scalable way and becomes work-conserving for free.

  • A Novel Spatial Absorbing Layer Using Discrete Green's Function Based on 3D SCN TLM for Waveguide Components

    Byungsoo KIM  Kyesuk JUN  Ihn Seok KIM  

     
    PAPER-Electromagnetic Theory

      Vol:
    E86-C No:12
      Page(s):
    2494-2500

    In this paper, the absorbing property of the discrete Green's function ABC, which was based on a powerful concept of the TLM method, has been improved by relocating loss process from the time domain to the space domain. The proposed scheme simply adds a loss matrix to the connection matrix in the basic TLM algorithm to make the formulation of the ABC more efficient. Various lengths of absorbing layers discretized for a WR-90 empty waveguide have been tested in terms of reflection property. An expression for an optimum absorbing property has been also derived with respect to the length of the layer. Comparison of the layer with the discrete Green's function ABC shows that the layer in this study has improved reflection property better than approximately 3 and 6 dB, respectively, when 50Δ and 60Δ absorbing layers have been adopted for the WR-90 waveguide. Finally, the layer has been applied to a WR-75 metal insert filter as an example.

2961-2980hit(4570hit)