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[Keyword] FA(3430hit)

1421-1440hit(3430hit)

  • On Outage Probability of Limited Feedback Beamforming with Receive Antenna Selection

    Erlin ZENG  Shihua ZHU  Xuewen LIAO  Zhimeng ZHONG  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E91-B No:12
      Page(s):
    4034-4037

    This letter analyzes the outage probability of limited feedback beamforming systems with receive antenna selection. Tight analytical closed-form expressions of outage performance are derived for both cases, with and without spatial fading correlation, which allow for evaluation of the performance as a function of the codebook size, the level of fading correlation, and the number of transmit and receive antennas. Simulation results are also provided to verify the analysis.

  • Electrocatalytic Oxidation Properties of Ascorbic Acid at Poly(3,4-ethylenedioxythiophene) Films Studied by Electrochemical-Surface Plasmon Resonance Spectroscopy

    Akira BABA  Yohsuke SANO  Yasuo OHDAIRA  Kazunari SHINBO  Keizo KATO  Futao KANEKO  

     
    LETTER-Materials & Devices

      Vol:
    E91-C No:12
      Page(s):
    1881-1882

    In this report, we demonstrate electrocatalytic oxidation properties of ascorbic acid at poly(3,4-ethylenedioxythiophene) (PEDOT) thin films in view of their potential application for bio-sensing devices. PEDOT thin films were deposited on gold thin films by electropolymerization of EDOT monomer in acetonitrile solvent. In-situ electrochemical-surface plasmon resonance spectroscopy (EC-SPR) was used to detect both electrochemical and optical signals upon an injection of ascorbic acid.

  • Maximizing Stuck-Open Fault Coverage Using Stuck-at Test Vectors

    Yoshinobu HIGAMI  Kewal K. SALUJA  Hiroshi TAKAHASHI  Shin-ya KOBAYASHI  Yuzo TAKAMATSU  

     
    PAPER-Logic Synthesis, Test and Verification

      Vol:
    E91-A No:12
      Page(s):
    3506-3513

    Physical defects that are not covered by stuck-at fault or bridging fault model are increasing in LSI circuits designed and manufactured in modern Deep Sub-Micron (DSM) technologies. Therefore, it is necessary to target non-stuck-at and non-bridging faults. A stuck-open is one such fault model that captures transistor level defects. This paper presents two methods for maximizing stuck-open fault coverage using stuck-at test vectors. In this paper we assume that a test set to detect stuck-at faults is given and we consider two formulations for maximizing stuck-open coverage using the given test set as follows. The first problem is to form a test sequence by using each test vector multiple times, if needed, as long as the stuck-open coverage is increased. In this case the target is to make the resultant test sequence as short as possible under the constraint that the maximum stuck-open coverage is achieved using the given test set. The second problem is to form a test sequence by using each test vector exactly once only. Thus in this case the length of the test sequence is maintained as the number of given test vectors. In both formulations the stuck-at fault coverage does not change. The effectiveness of the proposed methods is established by experimental results for benchmark circuits.

  • Active Frequency Selective Surfaces Using Incorporated PIN Diodes

    Kihun CHANG  Sang il KWAK  Young Joong YOON  

     
    PAPER-Electromagnetic Theory

      Vol:
    E91-C No:12
      Page(s):
    1917-1922

    In this paper, active frequency selective surfaces (FSS) having a squared aperture with a metal plate loading are described. Active FSS elements using switched PIN diodes are discussed with an equivalent circuit model. A unit cell consists of a square aperture element with metal island loading and one PIN diode placed at the upper gap, considering the vertical polarization. The electromagnetic properties of the active FSS structure are changed by applying dc bias to the substrate, and they can be estimated by the equivalent circuit model of the FSS structure and PIN diode. This active FSS design enables transmission to be switched on or off at 2.3 GHz, providing high transmission when the diodes are in an off state and high isolation when the diodes are on. The equivalent circuit model in the structure is investigated by analyzing transmission and reflection spectra. Measurements on active FSS are compared with numerical calculations. The experimentally observed frequency responses are also scrutinized.

  • Channel Estimation and Code Word Inference for Mobile Digital Satellite Broadcasting Reception

    Masatoshi HAMADA  Shiro IKEDA  

     
    PAPER-Fundamental Theories for Communications

      Vol:
    E91-B No:12
      Page(s):
    3886-3898

    This paper proposes a method of improving reception of digital satellite broadcasting in a moving vehicle. According to some studies, the antennas used for mobile reception will be smaller in the next generation and reception will be more difficult because of a fading multipath channel with delays in a low carrier-to-noise ratio. Commonly used approaches to reduce the inter symbol interference caused by a fading multipath channel with delays are pilot sequences and diversity reception. Digital satellite broadcasting, however, does not transmit pilot sequences for channel estimation and it is not possible to install multiple antennas in a vehicle. This paper does not propose any change to the broadcasting standards but discusses how to process currently available digital satellite signals to obtain better results. Our method does not rely on the pilot sequences or diversity reception, but consists of channel estimation and stochastic inference methods. For each task, two methods are proposed. The maximum likelihood estimation and higher order statistics matching methods are proposed for the estimation, and the marginal with the joint probability inference methods are proposed for the stochastic inference. The improvements were confirmed through experiments with numerical simulations and real data. The computational costs are also discussed for future implementation.

  • Characterization of Zinc Oxide and Pentacene Thin Film Transistors for CMOS Inverters

    Hiroyuki IECHI  Yasuyuki WATANABE  Hiroshi YAMAUCHI  Kazuhiro KUDO  

     
    PAPER-Transistors

      Vol:
    E91-C No:12
      Page(s):
    1843-1847

    We fabricated both thin film transistors (TFTs) and diodes using zinc oxide (ZnO) and pentacene, and investigated their basic characteristics. We found that field-effect mobility is influenced by the interface state between the semiconductor and dielectric layers. Furthermore, the complementary metal oxide semiconductor (CMOS) inverter using a p-channel pentacene field-effect transistor (FET) and an n-channel ZnO FET showed a relatively high voltage gain (8-12) by optimizing the device structure. The hybrid complementary inverters described here are expected for application in flexible displays, radio frequency identification cards (RFID) tags, and others.

  • High Throughput VLSI Architecture of a Fast Mode Decision Algorithm for H.264/AVC Intra Encoding

    Tianruo ZHANG  Guifen TIAN  Takeshi IKENAGA  Satoshi GOTO  

     
    PAPER-Embedded, Real-Time and Reconfigurable Systems

      Vol:
    E91-A No:12
      Page(s):
    3630-3637

    Intra coding in H.264/AVC has significantly enhanced video compression efficiency. However, computation complexity increases by the rate-distortion (RD) based mode decision. This paper proposes a novel fast mode decision algorithm in H.264/AVC intra prediction and its VLSI architecture. A novel edge-detection pattern is proposed and both edge-detection technique and spatial mode prediction technique are combined together to reduce the number of intra 44 candidate modes from 9 to an average of 2.50. VLSI architecture of intra mode decision module is designed with TSMC 0.18 µm CMOS technology. The maximum frequency of 285 MHz is achieved and 13.1k NAND gates are required. High frequency, efficient processing cycle reduction and small area make this design to be an excellent accelerator for HDTV 1080p@30 fps real time encoder.

  • Surface Plasmon Excitation and Emission Light Property for Otto/Kretschmann Configuration with MEH-PPV Film

    Megumi HAFUKA  Masahiro MINAGAWA  Yasuo OHDAIRA  Akira BABA  Kazunari SHINBO  Keizo KATO  Futao KANEKO  

     
    LETTER-Materials & Devices

      Vol:
    E91-C No:12
      Page(s):
    1883-1884

    Attenuated total reflection (ATR) property utilizing surface plasmon (SP) excitation was investigated for BK-7 prism/MgF2/Ag film/fluorescent organic dye film structure. In the structure, it is expected that SPs are excited at MgF2/Ag and Ag/dye film interfaces by Otto and Kretschmann configurations, respectively. In the experimental ATR curve, reflection dips for the SP excitations at the interfaces could be detected. Furthermore, SP emission lights were observed by irradiation of Ar ion laser beam from the dye film side. The SP emission light curve with two peaks was observed and it was also considered that the peaks corresponded to the SP excitation of Otto and Kretschmann configurations. The SP emission light spectra indicated the excited fluorescent dyes induced the SP emission lights. Intense emission light of Otto configuration was observed in this sample.

  • On Fault Testing for Reversible Circuits

    Satoshi TAYU  Shigeru ITO  Shuichi UENO  

     
    PAPER-Complexity Theory

      Vol:
    E91-D No:12
      Page(s):
    2770-2775

    It has been known that testing of reversible circuits is relatively easier than conventional irreversible circuits in the sense that few test vectors are needed to cover all stuck-at faults. This paper shows, however, that it is NP-hard to generate a minimum complete test set for stuck-at faults on the wires of a reversible circuit using a polynomial time reduction from 3SAT to the problem. We also show non-trivial lower bounds for the size of a minimum complete test set.

  • Analyzing Bioelectric Potential Response of Plants Related to Photosynthesis under Blinking Irradiation

    Ki ANDO  Yuki HASEGAWA  Hitoshi MAEKAWA  Teruaki KATSUBE  

     
    PAPER-Bioelectronics

      Vol:
    E91-C No:12
      Page(s):
    1905-1909

    The bioelectric potential of plants is generated by ion concentration difference between inside and outside of plant cells. It has been reported that the bioelectric potential of leaves changes at the beginning of steady irradiation and intensity of the potential response increases with the photosynthetic rate. Although it has been reported that photosynthesis is accelerated by blinking irradiation, the potential response under the blinking irradiation have not been fully clarified. In this study, we measured the bioelectric potential and CO2 consumption of plants under various types of the blinking irradiation. This result showed that the potential response under the blinking irradiation has various behaviors and intensity of the response related to photosynthetic rate. We conclude that our method is suitable for monitoring the biological activity of plants such as photosynthesis.

  • Autonomous Repair Fault Tolerant Dynamic Reconfigurable Device

    Kentaro NAKAHARA  Shin'ichi KOUYAMA  Tomonori IZUMI  Hiroyuki OCHI  Yukihiro NAKAMURA  

     
    PAPER-Embedded, Real-Time and Reconfigurable Systems

      Vol:
    E91-A No:12
      Page(s):
    3612-3621

    Recently, reconfigurable devices are widely used in the fields of small amount production and trial production. They are also expected to be utilized in such mission-critical fields as space development, because system update and pseudo-repair can be achieved remotely by reconfiguring. However, in the case of conventional reconfigurable devices, configuration memory upsets caused by radiation and alpha particles reconfigure the device unpredictably, resulting in fatal system failures. Therefore, a reconfigurable device with high fault-tolerance against configuration upsets is required. In this paper, we propose an architecture of a fault-tolerant reconfigurable device that autonomously repairs configuration upsets by itself without interrupting system operations. The device consists of a 2D array of "Autonomous-Repair Cells" each of which repairs its upsets autonomously. The architecture has a scalability in fault tolerance; a finer-grained Autonomous-Repair Cell provides higher fault-tolerance. To determine the architecture, we analyze four autonomous repair techniques of the cell experimentally. Then, two autonomous repair techniques, simple multiplexing (S.M.) and memory multiplexing (M.M.), are applied; the former to programmable logics and the latter to cell-to-cell routing resources. Through evaluation, we show that proposed device achieves more than 10 years average lifetime against configuration upsets even in a severe situation such as a satellite orbit.

  • Routing Autonomous Vehicles in the Improving Initial Task Assignment and Avoiding Deadlock Method

    Yusuke MORIHIRO  Toshiyuki MIYAMOTO  Sadatoshi KUMAGAI  

     
    PAPER

      Vol:
    E91-A No:11
      Page(s):
    3229-3236

    This paper discusses an on-line Tasks Assignment and Routing Problem (TARP) for Autonomous Transportation Systems (ATSs) in manufacturing systems. The TARP is a constrained version of the Pickup and Delivery Problem with Time Windows (PDPTW). In our former study, a cooperative algorithm, called the triple loop method, with autonomous distributed agents has been proposed. The Improving initial Task Assignment and Avoiding Deadlock method (ITAAD) is a faster algorithm than the triple loop method. In this paper, we propose a new vehicle routing method for the ITAAD. Results of computational experiments show effectiveness of the proposed routing method.

  • Pseudolinear Circuit Theory for Sinusoidal Oscillator Performance Maximization

    Takashi OHIRA  Tuya WUREN  

     
    INVITED PAPER

      Vol:
    E91-C No:11
      Page(s):
    1726-1737

    This paper introduces a theory for fast optimization of the circuit topology and parameters in sinusoidal oscillators. The theory starts from a system model composed of standard active and passive elements. We then include even the output load in the circuit, so that there is no longer any interaction with the outside of the system through the port. This model is thus called no-input-no-output (NINO) oscillator. The circuit is cut at an arbitrary branch, and is characterized in terms of the scalar impedance from the cut point. This is called active impedance because it is a function of not only the stimulating frequency but also the active device gain. The oscillation frequency and necessary device gain are estimated by solving impedance-domain Barkhausen equilibrium equations. This estimation works for the adjustment of circuit elements to meet the specified oscillation frequency. The estimation of necessary device gain enables us to maximize the oscillation amplitude, thanks to the inherent negative-slope nonlinearity of active devices. The active impedance is also used to derive the oscillation Q (quality) factor, which serves as a key criterion for sideband noise minimization i.e. frequency spectrum purification. As an alternative measure to active impedance, we also introduce branch admittance matrix determinant. This has the same numerical effect as the scalar impedance but can be used to formulate oscillator characteristics in a more elegant fashion, and provides a lucent picture of the physical behavior of each element in the circuit. Based on the proposed theory, we provide the tabled formulas of oscillation frequency, necessary device gain, active Q factor for a variety of typical Colpitts, Hartley, and cross-coupled twin-FET (field-effect transistor) oscillators.

  • Multipath Diversity through Time Shifted Sampling for Spatially Correlated OFDM-Antenna Array Systems

    Refik Çalar KIZILIRMAK  Yukitoshi SANADA  

     
    PAPER

      Vol:
    E91-A No:11
      Page(s):
    3104-3111

    An essential condition for diversity reception is that the fading distributions between individual received signals of an antenna array are uncorrelated. In this paper, a new technique to improve the performance of transmission with the correlated Rayleigh-fading signals is proposed. In conventional array systems, individual receivers start sampling the received signals at the same time with the same sampling rate. On the other hand, in the proposed scheme, the received signals are again sampled with the same rate, however the sampling points are shifted in each receiver. Numerical results through computer simulation show that with correlated received signals, by applying the proposed technique the correlation can be reduced to a sufficient level for diversity reception.

  • Hybrid Fault Tolerant Peer to Peer Video Streaming Architecture

    Kasm ÖZTOPRAK  Gözde Bozdai AKAR  

     
    PAPER-Network

      Vol:
    E91-B No:11
      Page(s):
    3627-3638

    In this paper, we propose a fault tolerant hybrid p2p-CDN video streaming arhitecture to overcome the problems caused by peer behavior in peer-to-peer (P2P) video streaming systems. Although there are several studies modeling and analytically investigating peer behaviors in P2P video streaming systems, they do not come up with a solution to guarantee the required Quality of the Services (QoS). Therefore, in this study a hybrid geographical location-time and interest based clustering algorithm is proposed to improve the success ratio and reduce the delivery time of required content. A Hybrid Fault Tolerant Video Streaming System (HFTS) over P2P networks conforming the required QoS and Fault Tolerance is also offered. The simulations indicate that the required QoS can be achieved in streaming video applications using the proposed hybrid approach.

  • Pen-Based Interface Using Hand Motions in the Air

    Yu SUZUKI  Kazuo MISUE  Jiro TANAKA  

     
    PAPER-Knowledge Applications and Intelligent User Interfaces

      Vol:
    E91-D No:11
      Page(s):
    2647-2654

    A system which employs a stylus as an input device is suitable for creative activities like writing and painting. However, such a system does not always provide the user with a GUI that is easy to operate using the stylus. In addition, system usability is diminished because the stylus is not always integrated into the system in a way that takes into consideration the features of a pen. The purpose of our research is to improve the usability of a system which uses a stylus as an input device. We propose shortcut actions, which are interaction techniques for operation with a stylus that are controlled through a user's hand motions made in the air. We developed the Context Sensitive Stylus as a device to implement the shortcut actions. The Context Sensitive Stylus consists of an accelerometer and a conventional stylus. We also developed application programs to which we applied the shortcut actions; e.g., a drawing tool, a scroll supporting tool, and so on. Results from our evaluation of the shortcut actions indicate that users can concentrate better on their work when using the shortcut actions than when using conventional menu operations.

  • Fast Tracking of a Real Sinusoid with Multiple Forgetting Factors

    Md. Tawfiq AMIN  Kenneth Wing-Kin LUI  Hing-Cheung SO  

     
    LETTER-Digital Signal Processing

      Vol:
    E91-A No:11
      Page(s):
    3374-3379

    In this paper, a recursive Gauss-Newton (RGN) algorithm is first developed for adaptive tracking of the amplitude, frequency and phase of a real sinusoid signal in additive white noise. The derived algorithm is then simplified for computational complexity reduction as well as improved with the use of multiple forgetting factor (MFF) technique to provide a flexible way of keeping track of the parameters with different rates. The effectiveness of the simplified MFF-RGN scheme in sinusoidal parameter tracking is demonstrated via computer simulations.

  • SER Performance Analysis and Optimum Power Allocation for a Cooperative ARQ Protocol in Wireless Networks

    Luu Quoc TIN  Hyung-Yun KONG  

     
    LETTER-Wireless Communication Technologies

      Vol:
    E91-B No:11
      Page(s):
    3736-3739

    In incremental relaying, the destination uses a checking system and requires a retransmission from the relay in case an error happens. After receiving the signal from the relay, the destination combines the signals from the source and the relay and performs detection. However, the combined signal is actually worse because of the erroneous signal from the source. Our scheme eliminates the detrimental signal from the source and uses only the fresh signal from the relay, resulting in a large performance improvement and reduced complexity. The symbol error rate (SER) and its upper bound are established to analyze the power allocation strategy. Simulations verify the rightness of the theoretic studies, and many benefits of cooperative ARQ schemes are revealed.

  • Outage Probability of Dual-Hop Amplify-and-Forward Relaying Systems over Shadowed Nakagami-m Fading Channels

    Weiguang LI  Jun-Bo WANG  Ming CHEN  

     
    LETTER-Communication Theory and Signals

      Vol:
    E91-A No:11
      Page(s):
    3403-3405

    This paper studies a dual-hop amplify-and-forward (AF) relaying systems over shadowed Nakagami-m fading channels and derives an approximate analytical expression for the outage probability. The numerical results show that the derived analytical expression can provide very well approximations to the simulation results.

  • An Evaluation System for End-User Computing Capability in a Computing Business Environment

    Chui Young YOON  

     
    PAPER-Knowledge Representation

      Vol:
    E91-D No:11
      Page(s):
    2607-2615

    We describe an evaluation system consisting of an evaluation and interpretation model to totally assess and interpret an end-user's computing capability. It includes four evaluation factors and eighteen items, the complex indicators, an evaluation process, and method. We verified the model construct was verified by factor analysis and reliability analysis through a pilot test. We confirmed the application of the developed system by applying the model to evaluating end-users in a computing business environment and presenting the results. This system contributes to developing a practical system for evaluating an end-user's computing capability and hence for improving computing capability of end-users.

1421-1440hit(3430hit)