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[Keyword] Ti(30728hit)

22401-22420hit(30728hit)

  • A Child Verb Learning Model Based on Syntactic Bootstrapping

    Tiansheng XU  Zenshiro KAWASAKI  Keiji TAKIDA  Zheng TANG  

     
    PAPER-Artificial Intelligence, Cognitive Science

      Vol:
    E85-D No:6
      Page(s):
    985-993

    This paper presents a child verb learning model mainly based on syntactic bootstrapping. The model automatically learns 4-5-year-old children's linguistic knowledge of verbs, including subcategorization frames and thematic roles, using a text in dialogue format. Subcategorization frame acquisition of verbs is guided by the assumption of the existence of nine verb prototypes. These verb prototypes are extracted based on syntactic bootstrapping and some psycholinguistic studies. Thematic roles are assigned by syntactic bootstrapping and other psycholinguistic hypotheses. The experiments are performed on the data from the CHILDES database. The results show that the learning model successfully acquires linguistic knowledge of verbs and also suggest that psycholinguistic studies of child verb learning may provide important hints for linguistic knowledge acquisition in natural language processing (NLP).

  • A Shield Strip Type Low Impedance Line Component Using a Conducting Polymer for a Wide Frequency Band De-Coupler Set

    Koichiro MASUDA  Hirokazu TOHYA  Masaharu SATOH  

     
    PAPER-Fabrication and Characterization of Thin Films

      Vol:
    E85-C No:6
      Page(s):
    1317-1322

    Digitalization in electronic systems requires the electronics devices in de-coupler sets with low impedance at high frequency, and high reliability. A shield strip type line component with aluminum substrate, its surface oxidized dielectric layer and a conducting polymer electrolyte has been developed. The conducting polymers of polypyrrole and poly(3,4-ethylenedioxythiophene) have been formed by direct chemical oxidative polymerization and electrochemical polymerization on a dielectric layer. Thus, the surface of the dielectric layer is covered with conducting polymer films. The structure of the line component is strip line conformation just like a crushed coaxial cable with in-put and out-put terminals surrounded by the conducting polymer electrolyte. Two types of the components, i.e., a large surface area, 10 20 mm, and a small surface area, 4 4 mm, have been fabricated with polypyrrole and poly(3,4-ethylenedioxythiophene), respectively. The dielectric properties of these line components have been investigated with a Impedance/Gain-phase analyzer and a network analyzer. Due to the high conductivity of the polymer electrolytes, the line components demonstrate low impedance at resonance frequency. Regarding the frequency characteristics of the line components, the impedance and ESR at high frequency are lower than those of the conventional capacitors. Furthermore, the transfer coefficients, S21, are three orders lower than those of other capacitors in a wide frequency band from 10 kHz to 6 GHz. The results indicate the excellent characteristics of the line components for the power line de-coupler set at the boundary of the closed circuit unit.

  • Binary Sequences with Orthogonal Subsequences and a Zero-Correlation Zone: Pair-Preserving Shuffled Sequences

    Takafumi HAYASHI  

     
    LETTER-Coding Theory

      Vol:
    E85-A No:6
      Page(s):
    1420-1425

    In this paper, we present a new approach to the construction of a set of binary sequences with a zero-correlation zone. The set consists of n pairs of binary sequences and the length of each binary sequence is n2(m+2) for some integers m and n. The Hadamard sequences with length n are used to construct the set. Any sequence in the set has 2(m+1) subsequences, each of length 2n. The author proves that any two subsequences are orthogonal if they belong to different pairs of binary sequences in the set.

  • Design and Simulation of 4Q-Multiplier Using Linear and Saturation Regions of MOSFET Complementally

    Tsutomu SUZUKI  Takao OURA  Teru YONEYAMA  Hideki ASAI  

     
    PAPER

      Vol:
    E85-A No:6
      Page(s):
    1242-1248

    A new four-quadrant (4Q) Multiplier complementally using linear and saturation regions of MOSFET (Metal Oxide Semiconductor Field Effect Transistor) is proposed for the wide dynamic range and superior flexibility of the input range. This multiplier operates in the region except for the threshold voltage VT to zero. The validity of the proposed circuit is confirmed through HSPICE simulation.

  • Application of Organic Light Emitting Diode Based on the Alq3 Emissive Layer to the Electro-Optical Conversion Device

    Hirotake KAJII  Takahisa TSUKAGAWA  Takayuki TANEDA  Yutaka OHMORI  

     
    LETTER-Electronic Devices

      Vol:
    E85-C No:6
      Page(s):
    1245-1246

    The optical pulses of 50 MHz has been obtained from an organic light emitting diode (OLED) based on the Alq3 emissive layer with the active area of 0.01 mm2. We demonstrate that the OLEDs can be applied to fields of optical communication as the electro-optical conversion device for transmitting the signals of moving picture.

  • Photoirradiation Effects on Light-Emitting Devices Based on Poly (p-phenylene vinylene) Derivative

    Kazuya TADA  Mitsuyoshi ONODA  

     
    PAPER-Electronic Devices

      Vol:
    E85-C No:6
      Page(s):
    1227-1232

    Photoirradiation effects on the polymer light-emitting devices (PLEDs) with a semitransparent-Al cathode have been studied. A light-emitting polymers, a poly (p-phenylene vinylene) derivative MDOPPV has been used in this study. Upon photoirradiation, the emission intensity at a constant voltage was rapidly decreased. However, the quantum efficiency of electroluminescence remained constant, indicating the spatial separation between recombination zone and photooxidized defects. On the other hand, the quantum efficiency of photoluminescence rapidly dropped upon similar photoirradation. These can be understood by taking the difference in the spatial distribution and the origin of excitons between electro- and photo-luminescence processes. It was also found that the photooxidation rate of the polymer film whose thickness is ca. 100 nm does not have thickness dependence, suggesting that the photooxidation of the polymer proceeds uniformly throughout the device.

  • A Computationally Efficient Algorithm for Exponential B-Splines Based on Difference/IIR Filter Approach

    Takeshi ASAHI  Koichi ICHIGE  Rokuya ISHII  

     
    PAPER

      Vol:
    E85-A No:6
      Page(s):
    1265-1273

    This paper proposes a fast method for the calculation of exponential B-splines sampled at regular intervals. This algorithm is based on a combination of FIR and IIR filters which enables a fast decomposition and reconstruction of a signal. When complex values are selected for the parameters of the exponentials, complex trigonometric functions are obtained. Only the real part of these functions are used for the interpolation of real signals, leading less bandlimited signals when they are compared with the polynomial B-spline counterparts. These characteristics were verified with 1-D and 2-D examples. This paper also discusses the effectiveness of exponential B-splines, when they are applied to image processing.

  • Estimation of Multi-Layer Tissue Conductivities from Non-invasively Measured Bioresistances Using Divided Electrodes

    Xueli ZHAO  Yohsuke KINOUCHI  Tadamitsu IRITANI  Tadaoki MORIMOTO  Mieko TAKEUCHI  

     
    PAPER-Medical Engineering

      Vol:
    E85-D No:6
      Page(s):
    1031-1038

    To estimate inner multi-layer tissue conductivity distribution in a cross section of the local tissue by using bioresistance data measured noninvasively on the surface of the tissue, a measurement method using divided electrodes is proposed, where a current electrode is divided into several parts. The method is evaluated by computer simulations using a three-dimension (3D) model and two two-dimension (2D) models. In this paper, conductivity distributions of the simplified (2D) model are analyzed based on a combination of a finite difference method (FDM) and a steepest descent method (SDM). Simulation results show that conductivity values for skin, fat and muscle layers can be estimated with an error less than 0.1%. Even though different strength random noise is added to measured resistance values, the conductivities are estimated with reasonable precise, e.g., the average error is about 4.25% for 10% noise. The configuration of the divided electrodes are examined in terms of dividing pattern and the size of surrounding guard electrodes to confine and control the input currents from the divided electrodes within a cross sectional area in the tissue.

  • Dynamic Mobility Management for Cellular Networks: A Delayed Renewal Process Approach

    Ramon M. RODRIGUEZ-DAGNINO  Jorge J. RUIZ-CEDILLO  Hideaki TAKAGI  

     
    PAPER-Fundamental Theories

      Vol:
    E85-B No:6
      Page(s):
    1069-1074

    Tracking mobile users in cellular wireless networks involves two basic functions: location update and paging. Location update refers to the process of tracking the location of mobile users that are not in conversation. Three basic algorithms have been proposed in the literature, namely the distance-based, time-based, and movement-based algorithms. The problem of minimizing the location update and paging costs has been solved in the literature by considering exponentially distributed Cell Residence Times (CRT) and Inter-Call Time (ICT), which is the time interval between two consecutive phone calls. In this paper we select the movement-based scheme since it is effective and easy to implement. Applying the theory of the delayed renewal process, we find the distribution of the number of cell crossings when the ICT is a mixture of exponentially distributed random variables and the CRT comes from any distribution with Laplace transform. In particular, we consider the case in which the first CRT may have a different distribution from the remaining CRT's, which includes the case of circular cells. We aim at the total cost minimization in this case.

  • Polarization Fatigue Modeling of Ferroelectric Capacitors

    Kiyoshi NISHIMURA  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E85-C No:6
      Page(s):
    1334-1341

    We developed a novel model for degradation of remanent polarization resulting from repeated polarization reversal cycling. The characteristics of ferroelectric capacitors have been simulated with the double saturation function model that required only five parameters; Ec, Qrmax, Qdmax, Kr and Kd. This novel model combines an equivalent gap capacitor with the double saturation function model. The model predicts hysteresis loops under endurance conditions. The simulated results are well in agreement with the results obtained in the experiment. The model is utilized to quantify the degradation effect of remanent polarization on ferroelectric memory applications.

  • Electrical and Emitting Properties of Organic Electroluminescent Diodes with Nanostructured Cathode Buffer-Layers of Al/Alq3 Ultrathin Films

    Kazunari SHINBO  Eigo SAKAI  Futao KANEKO  Keizo KATO  Takahiro KAWAKAMI  Toyoyasu TADOKORO  Shinichi OHTA  Rigoberto C. ADVINCULA  

     
    PAPER-Electronic Devices

      Vol:
    E85-C No:6
      Page(s):
    1233-1238

    Organic light emitting diodes (OLEDs) containing nanostructured cathode buffer layers were fabricated, and their electrical and emitting properties were investigated. The OLEDs have an ITO anode/CuPc/TPD/Alq3/buffer layer/Al cathode structure with the buffer layers made from nanostructured alternating layers Alq3 and Al. The driving voltage and the efficiency of the devices were improved by insertion of the buffer layer. It was estimated that some modulations of the Schottky barrier at the Alq3 and the Al cathode interface were induced due to the insertion of the buffer layer and it caused an enhancement of electron injection from the Al cathode.

  • Effect of Surface Hydrophilicity and Solution Chemistry on the Adsorption Behavior of Cytochrome c in Quartz Studied Using Slab Optical Waveguide (SOWG) Spectroscopy

    Jose H. SANTOS  Naoki MATSUDA  Zhi-mei QI  Akiko TAKATSU  Kenji KATO  

     
    PAPER-Optoelectronics and Photonics

      Vol:
    E85-C No:6
      Page(s):
    1275-1281

    The adsorption behavior of cytochrome c was investigated using slab optical waveguide (SOWG) absorption spectroscopy at the near ultraviolet region utilizing thin quartz plates as planar waveguides. SOWG absorption spectra of cytochrome c measured at constant time intervals showed significant influence of surface hydrophilicity and solution chemistry on the adsorption of this important heme protein in quartz surface. Being polar and typically amphoteric, the protein preferred adsorption on hydrophilic surface than on hydrophobic surface as implied by the lower absorbance data obtained in the latter than in the former. At lower ionic strength and in the absence of buffer, the protein molecules tend to adsorb on the quartz surface. Plots of near steady-state absorbance versus protein concentration follow hyperbolic pattern in the absence of buffer or at low ionic strength and become more linear as the buffer concentration is increased. The results presented here are explained in terms of the general qualitative understanding of protein adsorption at solid-aqueous interfaces and further aids in elucidating the properties of protein monolayers and films.

  • A Digital Image Watermarking Scheme Based on Vector Quantisation

    Minho JO  HyoungDo KIM  

     
    LETTER-Image Processing, Image Pattern Recognition

      Vol:
    E85-D No:6
      Page(s):
    1054-1056

    Compared with much research in the spatial-domain and transform-domain watermarking techniques, VQ-based watermarking technique has not been fully treated. A digital image watermarking scheme based on vector quantisation (VQ) is proposed to improve the degree of spreading watermark information. By partitioning the codebook into 3 groups, the scheme tries to embed one binary information for each block. The scheme spreads the watermark information almost evenly over the image with little extra distortion. The experimental results prove the efficiency and effectiveness of the scheme.

  • Analysis of SIR-Based Downlink Beamforming

    Holger BOCHE  Martin SCHUBERT  

     
    PAPER-Antenna and Propagation

      Vol:
    E85-B No:6
      Page(s):
    1160-1168

    Transmit beamforming is a promising way to increase the downlink capacity of wireless networks. Since all users are coupled via their radiation patterns, the beamforming vectors must be optimized along with power control. It is necessary to balance the signal-to-interference levels according to individual QoS requirements. This problem leads back to the minimization of the infinity-norm of a certain vector and has first been studied by Gerlach and Paulraj in [1]. It has been assumed that the optimum solution can be obtained by minimizing the 1-norm instead, thereby leading to a new problem, which is generally easier to handle. The analytical and numerical results in this paper, however, indicate that this conjecture is generally not valid. We characterize the case where the 1-norm solution also solves the infinity-norm problem. In particular, it is shown that for the special case of a 2-user scenario, both optimization problems are indeed equivalent and a closed-form solution can be given. The analytical results provide new insights into the problem of coupled downlink beamforming and offer a useful approach to the design of efficient and reliable algorithms.

  • Effect of Interfacial Space Charges and Coupling Electrodes on Organic Single Electron Tunneling Device

    Yutaka NOGUCHI  Mitsumasa IWAMOTO  Tohru KUBOTA  Shinro MASHIKO  

     
    PAPER-Electronic Devices

      Vol:
    E85-C No:6
      Page(s):
    1247-1252

    The threshold voltage of Coulomb staircase using organic molecules was analyzed by extending our previous model with only consideration of the metal/organic film interfacial space charge to the generalized one. The generalized model is helpful to examine coupling capacitance in organic double barrier tunneling junction (DBTJ). The current-voltage (I-V) characteristic of metal/polyimide (PI)/rhodamine-dendrimer (Rh-G2)/PI/metal junction was analyzed using this generalized model. The calculation results were in good agreement with our experimental data.

  • Near Field Optical Recording on Azopolymer Using a Sub-Microsecond Pulse

    Taiji IKAWA  Chang-Dae KEUM  Hideki TAKAGI  Masaaki TSUCHIMORI  Osamu WATANABE  Wataru MORI  Masaya HARADA  Masahiro TAWATA  Hiroshi SHIMOYAMA  

     
    LETTER-Optoelectronics and Photonics

      Vol:
    E85-C No:6
      Page(s):
    1287-1290

    The optical recording on an azopolymer surface by the optical fiber probe with a 100 nm diameter aperture was demonstrated. The 150 nm diameter pit was formed by the optical fiber probe coupled with a 50 ns pulse of 10 mW and 488 nm wavelength coherent light.

  • Proposal and Evaluation of Vibration Transducer with Minimal Magnetic Field Interference for Use in IME System by in-vitro Experiment

    Byung-Seop SONG  Tae-Yeon JUNG  Seung-Pyo CHAE  Myoung-Nam KIM  Jin-Ho CHO  

     
    LETTER-Microwaves, Millimeter-Waves

      Vol:
    E85-C No:6
      Page(s):
    1374-1377

    A new type of electromagnetic vibration transducer for use in an IME (implantable middle ear) system is presented and evaluated by in-vitro experiment. Because the new designed transducer includes two magnets glued together with the same pole facing inside the coil, it can reduce the interference from an environmental magnetic field. And the proposed transducer exhibits a high vibration efficiency and wide frequency response. Using dead human's temporal bone, in-vitro experiments were carried out and the results showed that the proposed vibration transducer will be properly used to implantable middle ear for mild to severe hearing loss patients.

  • Throughput Efficiency of the Fundamental Multi-Receiver Go-Back-N ARQ Scheme over a Dependent Packet-Error Channel

    Satomi AMAKI  Masaharu KOMATSU  

     
    PAPER-Reliability, Maintainability and Safety Analysis

      Vol:
    E85-A No:6
      Page(s):
    1371-1378

    It has been shown that the performances of single-receiver ARQ schemes are largely dependent on the packet-error process, i.e., for dependent packet-error environment, they are under- or over- estimated by analyzing them under the assumption that packet-errors occur at random. While, multi-receiver ARQ's have not been analyzed and evaluated for dependent packet-error process. In this paper, we analyze the throughput efficiency of the fundamental multi-receiver Go-back-N ARQ scheme, which can be implemented very simply, over an unreliable channel modeled by the two-state Markov process. Any receiver erroneously receives a packet with probability inherent to each state. From numerical results, we show that the throughput efficiency of the fundamental multi-receiver Go-Back-N ARQ scheme depends on the number of receivers, round-trip-delay, and the characteristic of the Markov process. Also we show that the throughput efficiency of the fundamental multi-receiver Go-Back-N ARQ scheme for larger decay factor and larger difference between packet error probability at each state is considerably better than that for the random error pattern.

  • Robust Image Watermarking Based on Minimal DCT-Quantization Errors

    Yong-Jun RYU  Keun-Young LEE  

     
    LETTER

      Vol:
    E85-A No:6
      Page(s):
    1336-1340

    The technique of the digital watermarking is one of the ways to resolve copyright ownership and verify originality of digital contents (e.g. text documents, audio, still images, video, etc.). In this paper, we obtained global robustness and minimal error through using frame based watermarking and including DC and AC coefficients of DCT transform, which extended conventional watermarking method having local robustness and error through using block based and/or AC coefficients only. As a result, the high robustness and quality of our method were proved by several attacks such as lossy image compression, linear filtering, additive noise, scaling, cropping and so on. Watermarks embedded by our method are survived most of JPEG compressions.

  • Loop and Address Code Optimization for Digital Signal Processors

    Jong-Yeol LEE  In-Cheol PARK  

     
    LETTER-Digital Signal Processing

      Vol:
    E85-A No:6
      Page(s):
    1408-1415

    This paper presents a new DSP-oriented code optimization method to enhance performance by exploiting the specific architectural features of digital signal processors. In the proposed method, a source code is translated into the static single assignment form while preserving the high-level information related to loops and the address computation of array accesses. The information is used in generating hardware loop instructions and parallel instructions provided by most digital signal processors. In addition to the conventional control-data flow graph, a new graph is employed to make it easy to find auto-modification addressing modes efficiently. Experimental results on benchmark programs show that the proposed method is effective in improving performance.

22401-22420hit(30728hit)