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  • 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.

  • An Elastic Net Learning Algorithm for Edge Linking of Images

    Jiahai WANG  Zheng TANG  Qiping CAO  Xinshun XU  

     
    PAPER-Neural Networks and Bioengineering

      Vol:
    E86-A No:11
      Page(s):
    2879-2886

    Edge linking is a fundamental computer vision task, yet presents difficulties arising from the lack of information in the image. Viewed as a constrained optimization problem, it is NP hard-being isomorphic to the classical Traveling Salesman Problem. This paper proposes a gradient ascent learning algorithm of the elastic net approach for edge linking of images. The learning algorithm has two phases: an elastic net phase, and a gradient ascent phase. The elastic net phase minimizes the path through the edge points. The procedure is equivalent to gradient descent of an energy function, and leads to a local minimum of energy that represents a good solution to the problem. Once the elastic net gets stuck in local minima, the gradient ascent phase attempts to fill up the valley by modifying parameters in a gradient ascent direction of the energy function. Thus, these two phases are repeated until the elastic net gets out of local minima and produces the shortest or better contour through edge points. We test the algorithm on a set of artificial images devised with the aim of demonstrating the sort of features that may occur in real images. For all problems, the systems are shown to be capable of escaping from the elastic net local minima and producing more meaningful contours than the original elastic net.

  • Calculation of Sommerfeld Integrals for Modeling Vertical Dipole Array Antenna for Borehole Radar

    Satoshi EBIHARA  Weng Cho CHEW  

     
    PAPER-Electromagnetic Theory

      Vol:
    E86-C No:10
      Page(s):
    2085-2096

    This paper describes a method for the fast evaluation of the Sommerfeld integrals for modeling a vertical dipole antenna array in a borehole. When we analyze the antenna inside a medium modeled by multiple cylindrical layers with the Method of Moment (MoM), we need a Green's function including the scattered field from the cylindrical boundaries. We focus on the calculation of Green's functions under the condition that both the detector and the source are situated in the innermost layer, since the Green's functions are used to form the impedance matrix of the antenna. Considering bounds on the location of singularities on a complex wave number plane, a fast convergent integration path where pole tracking is unnecessary is considered for numerical integration. Furthermore, as an approximation of the Sommerfeld integral, we describe an asymptotic expansion of the integrals along the branch cuts. The pole contribution of TM01 and HE11 modes are considered in the asymptotic expansion. To obtain numerical results, we use a fast convergent integration path that always proves to be accurate and efficient. The asymptotic expansion works well under specific conditions. The Sommerfeld integral values calculated with the fast evaluation method is used to model the array antenna in a borehole with the MoM. We compare the MoM data with experimental data, and we show the validity of the fast evaluation method.

  • Scenario-Based Web Services Testing with Distributed Agents

    Wei-Tek TSAI  Ray PAUL  Lian YU  Akihiro SAIMI  Zhibin CAO  

     
    PAPER-Testing

      Vol:
    E86-D No:10
      Page(s):
    2130-2144

    Web Services (WS) have received significant attention recently. Delivering Quality of Service (QoS) on the Internet is a critical and significant challenge for WS community. This article proposes a Web Services Testing Framework (WSTF) for WS participates to perform WS testing. WSTF provides three main distributed components: test master, test agents and test monitor. Test master manages scenarios and generates test scripts. It initiates WS testing by sending test scripts to test agents. Test agents dynamically bind and invoke the WS. Test monitors capture synchronous/asynchronous messages sent and received, attach timestamp, and trace state change information. The benefit to use WSTF is that the user only needs to specify system scenarios based on the system requirements without needing to write test code. To validate the proposed approach, this paper used the framework to test a supply-chain system implemented using WS.

  • Iterative Decoding of High Dimensionality Parity Code

    Toshio FUKUTA  Yuuichi HAMASUNA  Ichi TAKUMI  Masayasu HATA  Takahiro NAKANISHI  

     
    PAPER-Coding Theory

      Vol:
    E86-A No:10
      Page(s):
    2473-2482

    Given the importance of the traffic on modern communication networks, advanced error correction methods are needed to overcome the changes expected in channel quality. Conventional countermeasures that use high dimensionality parity codes often fail to provide sufficient error correction capability. We propose a parity code with high dimensionality that is iteratively decoded. It provides better error correcting capability than conventional decoding methods. The proposal uses the steepest descent method to increase code bit reliability and the coherency between parities and code bits gradually. Furthermore, the quantization of the decoding algorithm is discussed. It is found that decoding with quantization can keep the error correcting capability high.

  • Scene-Adaptive Frame-Layer Rate Control for Low Bit Rate Video

    Jae-Young PYUN  Yoon KIM  Sung-Jea KO  HwangJun SONG  

     
    LETTER-Source Coding/Image Processing

      Vol:
    E86-A No:10
      Page(s):
    2618-2622

    Rate control regulates the coded bit stream to satisfy certain given bit rate condition while maintaining the quality of coded video. However, most existing rate control algorithms for low bit rate video can not handle scene change properly, so visual quality is consequently worsened. The test model TMN8 of H.263+ can be forced to skip frames after an abrupt scene change. In this letter, we propose a new frame-layer rate control which allocates bits to frames and controls the frame skipping adaptively based on the pre-analysis of future frames. Experimental results show that the proposed control method provides an effective alternative to existing frame skipping methods causing the motion jerkiness and quality degradation.

  • A New Approach to Fuzzy Modeling Using an Extended Kernel Method

    Jongcheol KIM  Taewon KIM  Yasuo SUGA  

     
    PAPER-Neuro, Fuzzy, GA

      Vol:
    E86-A No:9
      Page(s):
    2262-2269

    This paper proposes a new approach to fuzzy inference system for modeling nonlinear systems based on measured input and output data. In the suggested fuzzy inference system, the number of fuzzy rules and parameter values of membership functions are automatically decided by using the extended kernel method. The extended kernel method individually performs linear transformation and kernel mapping. Linear transformation projects input space into linearly transformed input space. Kernel mapping projects linearly transformed input space into high dimensional feature space. Especially, the process of linear transformation is needed in order to solve difficulty determining the type of kernel function which presents the nonlinear mapping in according to nonlinear system. The structure of the proposed fuzzy inference system is equal to a Takagi-Sugeno fuzzy model whose input variables are weighted linear combinations of input variables. In addition, the number of fuzzy rules can be reduced under the condition of optimizing a given criterion by adjusting linear transformation matrix and parameter values of kernel functions using the gradient descent method. Once a structure is selected, coefficients in consequent part are determined by the least square method. Simulated results of the proposed technique are illustrated by examples involving benchmark nonlinear systems.

  • Full-Duplex Transmission Using 2-RF-Port Electroabsorption Transceiver with Photonic Up- and Downconversions for Millimeter-Wave Radio-on-Fiber System

    Kensuke IKEDA  Toshiaki KURI  Yoshiro TAKAHASHI  Ken-ichi KITAYAMA  

     
    PAPER-Photonic Links for Wireless Communications

      Vol:
    E86-C No:7
      Page(s):
    1138-1145

    Full-duplex transmission of 60.0 GHz and 59.6 GHz millimeter-wave (mm-wave) signals of 155.52-Mbit/s differential phase shift keying (DPSK) data, radio-on-fiber (ROF) signals over 25-km-long standard single-mode fibers (SMFs) is experimentally demonstrated for the first time using a single 2-RF-port electroabsorption transceiver (EAT). The simplification of base stations (BSs) is strongly required to realize cost-effective and high-reliability mm-wave wireless access. This single EAT detects a C-band ROF signal modulated by a mm-wave downlink signal and simultaneously modulates the L-band optical carrier by a mm-wave uplink signal. The BS mainly consists of the EAT, leading to a simple and low-cost BS. Optical pilot tones and optical bandpass filters are used for photonic downconversion and photonic upconversion, to convert frequencies between mm-wave signals and intermediate frequency (IF) signals in the optical domain. With the use of optical conversions, these signals have no significant fading problems. The simultaneous transmission of both up- and downlinks has been achieved with the BER of less than 10-9. Also the fading problems due to the fiber dispersion of photonic conversions are analyzed mathematically in this paper. The single-EAT BS will become a promising candidate for a ROF access system.

  • Construction Method of Fuzzy Inference by Rule Creation

    Michiharu MAEDA  Hiromi MIYAJIMA  

     
    LETTER

      Vol:
    E86-A No:6
      Page(s):
    1509-1512

    This paper describes two methods to construct fuzzy inference rules by the simplified fuzzy reasoning. The present methods have a construction mechanism of the rule unit that is applicable in two parameters: the central value and the width of the membership function in the antecedent part. The first approach is to create a rule unit near the selected rule which has the nearest position from the central input space for the central value. The second is to create a rule unit near the selected rule which has the minimum width for the width. Experimental results are presented in order to show that the proposed methods are effective in difference on the inference error and the number of learning iterations.

  • Growth and Characterization of Carbon Nanowalls

    Kazuhito NISHIMURA  Nan JIANG  Akio HIRAKI  

     
    PAPER

      Vol:
    E86-C No:5
      Page(s):
    821-824

    A type of carbon nanoform (carbon nanowalls: CNWs) has been successfully deposited on both Ni wafers and Ni wires using dc plasma chemical-vapor-deposition (CVD) method. Transmission electron microscopy (TEM) and Raman spectroscopy were used to characterize CNWs' microstructure. It is found that CNWs are well crystallized, and each CNW consists of several pieces of curved graphene sheets, presenting a quasi-two-dimensional geometry. The average length and width of CNWs are about 2-4µm, while their thickness is less than 7nm. Field emission measurement showed that such CNW films exhibited the excellent electron emission efficiency, comparable to the high-grade carbon nanotube (CNT) emitters. The threshold field defined as the field to obtained 1µA/cm2 is less than 1V/µm and the electrical field for 1mA/cm2 current density is only about 1.5V/µm. Moreover, the CNWs have stable emission behaviors, and we have successfully fabricated a kind of high-brightness lamps based on the CNW coated Ni wires.

  • An Ultra Low Power Motion Estimation Processor for MPEG2 HDTV Resolution Video

    Masayuki MIYAMA  Osamu TOOYAMA  Naoki TAKAMATSU  Tsuyoshi KODAKE  Kazuo NAKAMURA  Ai KATO  Junichi MIYAKOSHI  Kousuke IMAMURA  Hideo HASHIMOTO  Satoshi KOMATSU  Mikio YAGI  Masao MORIMOTO  Kazuo TAKI  Masahiko YOSHIMOTO  

     
    PAPER-Architecture and Algorithms

      Vol:
    E86-C No:4
      Page(s):
    561-569

    This paper describes an ultra low power, motion estimation (ME) processor for MPEG2 HDTV resolution video. It adopts a Gradient Descent Search (GDS) algorithm that drastically reduces required computational power to 6 GOPS. A SIMD datapath architecture optimized for the GDS algorithm decreases the clock frequency and operating voltage. A low power 3-port SRAM with a write-disturb-free cell array arrangement is newly designed for image data caches of the processor. The proposed ME processor contains 7-M transistors, integrated in 4.50 mm 3.35 mm area using 0.13 µm CMOS technology. Estimated power consumption is less than 100 mW at 81 MHz@1.0 V. The processor is applicable to a portable HDTV system.

  • A Gradient Ascent Learning Algorithm for Elastic Nets

    Zheng TANG  Jia Hai WANG  Qi Ping CAO  

     
    PAPER-Neural Networks and Bioengineering

      Vol:
    E86-A No:4
      Page(s):
    940-945

    This paper proposes a gradient ascent learning algorithm for the elastic net approach to the Traveling Salesman Problem (TSP). The learning model has two phases: an elastic net phase, and a gradient ascent phase. The elastic net phase is equivalent to gradient descent of an energy function, and leads to a local minimum of energy that represents a good solution to the problem. Once the elastic net gets stuck in local minima, the gradient ascent phase attempts to fill up the valley by modifying parameters in a gradient ascent direction of the energy function. Thus, these two phases are iterated until the elastic net gets out of local minima. We test the algorithm on many randomly generated travel salesman problems up to 100 cities. For all problems, the systems are shown to be capable of escaping from the elastic net local minima and generating shorter tour than the original elastic net.

  • A New Non-Pair Diffusion Based Dopant Pile-up Model for Process Designers and Its Prediction Accuracy

    Hirokazu HAYASHI  Noriyuki MIURA  Hirotaka KOMATSUBARA  Marie MOCHIZUKI  Koichi FUKUDA  

     
    PAPER

      Vol:
    E86-C No:3
      Page(s):
    453-458

    We propose an effective dopant pile-up model which is useful for device optimization in a short-term. Our purpose is that the model provides speedy calculation for numerous simulations constructed by design of experiment (DoE), and the calibration is also easy in practical range of process condition. The dopant pile-up in the Si/SiO2 interface is calculated using a non-pair diffusion model that solves one equation for each impurity, considering an essential physics where RSCE is due to the dopant pile-up in the Si/SiO2 interface. A non-pair diffusion for dopants and point defects is adequate for time length which can ignore their reactions. The key for the modeling of RSCE is that the dependence on various processes such as channel implantation and annealing conditions can be reproduced in the local process window. The capability of the model is investigated though the comparison to measurements in actual n-channel MOSFETs for different process technologies. We also check the prediction accuracy of the dopant profiles using our model. As a result, the optimization of 4 parameters for 25 jobs based on DoE is possible less than 2 hours using our model.

  • Audio-Visual Speech Recognition Based on Optimized Product HMMs and GMM Based-MCE-GPD Stream Weight Estimation

    Kenichi KUMATANI  Satoshi NAKAMURA  

     
    PAPER-Speech and Speaker Recognition

      Vol:
    E86-D No:3
      Page(s):
    454-463

    In this paper, we describe an adaptive integration method for an audio-visual speech recognition system that uses not only the speaker's audio speech signal but visual speech signals like lip images. Human beings communicate with each other by integrating multiple types of sensory information such as hearing and vision. Such integration can be applied to automatic speech recognition, too. In the integration of audio and visual speech features for speech recognition, there are two important issues, i.e., (1) a model that represents the synchronous and asynchronous characteristics between audio and visual features, and makes the best use of a whole database that includes uni-modal, audio only, or visual only data as well as audio-visual data, and (2) the adaptive estimation of reliability weights for the audio and visual information. This paper mainly investigates two issues and proposes a novel method to effectively integrate audio and visual information in an audio-visual Automatic Speech Recognition (ASR) system. First, as the model that integrates audio-visual speech information, we apply a product of hidden Markov models (product HMM), the product of an audio HMM and a visual HMM. We newly propose a method that re-estimates the product HMM using audio-visual synchronous speech data so as to train the synchronicity of the audio-visual information, while the original product HMM assumes independence from audio-visual features. Second, for the optimal audio-visual information reliability weight estimation, we propose a Gaussian mixture model (GMM) based-MCE-GPD (minimum classification error and generalized probabilistic descent) algorithm, which enables reductions in the amount of adaptation data and amount of computations required for the GMM estimation. Evaluation experiments show that the proposed audio-visual speech recognition system improves the recognition accuracy over conventional ones even if the audio signals are clean.

  • Implementation and Evaluation of TCP Protocol Tester Generating Exceptional Test Sequences

    Tomohiko OGISHI  Toru HASEGAWA  Toshihiko KATO  

     
    PAPER-Traffic Monitoring and Evaluation

      Vol:
    E86-B No:2
      Page(s):
    604-613

    Although TCP is widely used in the Internet, new specifications are still proposed and implemented. In the circumstance above, it is highly possible that some errors are detected on the communication between new and old implementations. Several test tools were developed so far. However, they do not have enough functions to allow test operators to modify test sequences suitable for their test purposes. We have developed a TCP tester which generates test sequence using test scenario. The tester performs exceptional TCP protocol behavior only when the condition specified in the test scenario is satisfied. Otherwise, it performs normal TCP behavior. The tester is implemented by modifying TCP module of NetBSD with SACK code developed by Pittsburgh Supercomputing Center. We have also evaluated implementations of congestion control and SACK algorithms using the tester.

  • A Study of a Stable Driving Circuit for Arbitrary-Shaped Electroluminescent Elements

    Yasuyuki KITADA  Noboru MASUDA  Hiroshi NAKANE  Sadao YAMAZAKI  

     
    PAPER

      Vol:
    E86-A No:2
      Page(s):
    404-410

    This paper deals with a method for designing the driving circuit of an electroluminescent (EL) element whose power consumption is lower and the deviation of output voltage is smaller even when the EL element is replaced with another of a different shape. In this driving circuit, an AC voltage raised by a step-up transformer is supplied to the EL element. The oscillation conditions in the orthodox driving circuits were theoretically analyzed, and a new driving circuit which incorporates these characteristics is proposed. A new prototype driving circuit taking the resonance characteristics between the capacitance of the element and the inductance of the transformer into consideration was made. In the experiment, an inorganic AC EL cable-type element was used as the load of the driving circuit as its impedance can be easily adjusted by changing its length. In comparison with orthodox circuits, the power consumption was lower and the changes in the output voltage were smaller in the new prototype circuit even when the changes in the impedance were large.

  • Experimental Verification of the Theory on Energy Modulation of an Electron Beam with an Optical Near-Field

    Ryo ISHIKAWA  Jongsuck BAE  Koji MIZUNO  

     
    PAPER

      Vol:
    E85-C No:12
      Page(s):
    2086-2092

    An exchange of energy between nonrelativistic electrons and evanescent waves in an optical near-filed has been investigated in an infrared region. A metal microslit has been adopted as an optical near-field generator which produces a number of evanescent waves by illumination of a laser beam. The theory has predicted that electrons interact selectively with the evanescent wave whose phase velocity is equal to the velocity of the electrons. In order to verify the theory, two types of precise microslits with different shapes, a slot and a V-shaped groove, have been fabricated. Experiments performed using these slits at the wavelength of 10.6 µm have shown that the energy change of the electrons has varied from 2 eV to 13 eV with their initial energy between 25-95 keV for a 3.2 kW CO2 laser pulse. The measured results have given experimental verifications to the theory.

  • Fluorescence Spectroscopy of Rb Atoms with Two-Color Optical Near Fields for a High-Resolution Slit-Type Detector

    Kouki TOTSUKA  Haruhiko ITO  Motoichi OHTSU  

     
    PAPER

      Vol:
    E85-C No:12
      Page(s):
    2093-2096

    We introduce stepwise resonant excitation by two-color optical near fields in order to detect Rb atoms with a slit-type detector. Blue fluorescence of the second D2 line is monitored for background-free detection. Feasibility of the method is shown from an experiment with a Rb vapor cell, where a sub-Doppler spectrum with the FWHM of 80 MHz is obtained. The detection efficiency is estimated at about 3% for cold Rb atoms.

  • High Resolution Optical Near-Field Spectroscopy Using Intrinsic Frequency Noise of Diode Laser

    Yasuo OHDAIRA  Hirokazu HORI  

     
    PAPER

      Vol:
    E85-C No:12
      Page(s):
    2097-2103

    Frequency modulation (FM) noise spectroscopy with diode laser is applied to high-resolution Doppler-free spectroscopy of Cs atomic vapor near a dielectric surface with evanescent-wave pump-probe configuration. Both high resolution and high sensitivity are realized by using an extremely simple experimental setup, in which no sweep or precise tuning of laser frequency are required. Several experimental configurations of optical near-field spectroscopy are demonstrated, which is useful for an extensive study of resonant interactions of atoms and microscopic electronic systems in optical near-fields.

  • A Simplified Dopant Pile-Up Model for Process Simulators

    Hirokazu HAYASHI  Noriyuki MIURA  Hirotaka KOMATSUBARA  Marie MOCHIZUKI  Koichi FUKUDA  

     
    PAPER-Semiconductor Materials and Devices

      Vol:
    E85-C No:12
      Page(s):
    2117-2122

    This paper describes an effective model which reproduces the dependence on the source/drain (S/D) process of the reverse short channel effect (RSCE) of the MOSFET threshold voltage (Vth). It is useful for local modeling which is effective within the limited process conditions. The proposed model is based on the physics where the key factor of RSCE is the dopant pile-up in the Si/SiO2 interface. The purpose of the model is for TCAD to be put to actual use as a quick solution tool. The calculation cost is much lower than a pair diffusion model, because the model is implemented in a conventional process simulator that solves one equation for each impurity. The capability of the simplified model is investigated for the dependence of various process conditions on the RSCE. Using our model, we also report the application of both the actual n-channel and p-channel MOSFETs.

221-240hit(344hit)