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[Keyword] components(44hit)

21-40hit(44hit)

  • Particle Swarms for Feature Extraction of Hyperspectral Data

    Sildomar Takahashi MONTEIRO  Yukio KOSUGI  

     
    PAPER-Pattern Recognition

      Vol:
    E90-D No:7
      Page(s):
    1038-1046

    This paper presents a novel feature extraction algorithm based on particle swarms for processing hyperspectral imagery data. Particle swarm optimization, originally developed for global optimization over continuous spaces, is extended to deal with the problem of feature extraction. A formulation utilizing two swarms of particles was developed to optimize simultaneously a desired performance criterion and the number of selected features. Candidate feature sets were evaluated on a regression problem. Artificial neural networks were trained to construct linear and nonlinear models of chemical concentration of glucose in soybean crops. Experimental results utilizing real-world hyperspectral datasets demonstrate the viability of the method. The particle swarms-based approach presented superior performance in comparison with conventional feature extraction methods, on both linear and nonlinear models.

  • Distortion Reduction Filters for Radio-on-Fiber System

    Shingo TANAKA  Noritaka TAGUCHI  Tsuneto KIMURA  Yasunori ATSUMI  

     
    PAPER

      Vol:
    E90-C No:2
      Page(s):
    365-372

    Three distortion reduction filters for radio-on-fiber systems are proposed and evaluated from the standpoint of improvements in in-band third order intermodulation (IM3) components (spurious components), insertion loss, temperature stability and so on. The basic filter configuration includes optical comb filter, RF (radiowave frequency) comb filter, and RF dual band rejection filter (DBRF). Experiments are conducted at 2 GHz band for frequency separation Δf=5 MHz and 100 MHz in the temperature range of -10 to +50. These filters can reduce IM3 components even in the saturation region, unlike conventional linearizers. An optical comb filter can reduce IM3 components more than 20 dB and noise level around 10 dB if its polarization controller is properly adjusted, but its insertion loss is large and stability against vibration is very poor. The proposed RF comb filter and RF-DBRF can reduce IM3 components by more than 20 dB and noise level by more than 3 dB. Their stability against vibration and temperature change is good, and insertion losses are 1-2 dB for Δf=100 MHz.

  • On the Expected Prediction Error of Orthogonal Regression with Variable Components

    Katsuyuki HAGIWARA  Hiroshi ISHITANI  

     
    PAPER-Algorithms and Data Structures

      Vol:
    E89-A No:12
      Page(s):
    3699-3709

    In this article, we considered the asymptotic expectations of the prediction error and the fitting error of a regression model, in which the component functions are chosen from a finite set of orthogonal functions. Under the least squares estimation, we showed that the asymptotic bias in estimating the prediction error based on the fitting error includes the true number of components, which is essentially unknown in practical applications. On the other hand, under a suitable shrinkage method, we showed that an asymptotically unbiased estimate of the prediction error is given by the fitting error plus a known term except the noise variance.

  • Multi-Stage, Multi-Way Microstrip Power Dividers with Broadband Properties

    Mitsuyoshi KISHIHARA  Isao OHTA  Kuniyoshi YAMANE  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E89-C No:5
      Page(s):
    622-629

    This paper presents a design method of multi-stage, multi-way microstrip power dividers with the aim of constructing a compact low-loss power divider with numbers of outputs. First, an integration design technique of power dividers composed of multi-step, multi-furcation and mitered bends is described. Since the analytical technique is founded on the planar circuit approach combined with the segmentation method, the optimization of the circuit patterns can be performed in a reasonable short computation time. Next, the present method is applied to the design of broadband Nn-way power dividers such as 32-way power divider consisting of 3-way dividers in two-stage structures, respectively. In addition, a 12-way power divider constructed from a series connection of a 3-way and three 4-way dividers is designed. The dividers equivalently contain a 3-section Chebyshev transformer to realize broadband properties. As a result, the fractional bandwidths of nearly 85% and 66.7% for the power-split imbalance less than 0.2 dB and the return loss better than -20 dB are obtained for the 9- and 12-way power dividers, respectively. The validity of these design results is confirmed by a commercial em-simulator (Ansoft HFSS) and experiments.

  • A Linear Time Algorithm for Binary Fingerprint Image Denoising Using Distance Transform

    Xuefeng LIANG  Tetsuo ASANO  

     
    PAPER-Image Processing and Video Processing

      Vol:
    E89-D No:4
      Page(s):
    1534-1542

    Fingerprints are useful for biometric purposes because of their well known properties of distinctiveness and persistence over time. However, owing to skin conditions or incorrect finger pressure, original fingerprint images always contain noise. Especially, some of them contain useless components, which are often mistaken for the terminations that are an essential minutia of a fingerprint. Mathematical Morphology (MM) is a powerful tool in image processing. In this paper, we propose a linear time algorithm to eliminate impulsive noise and useless components, which employs generalized and ordinary morphological operators based on Euclidean distance transform. There are two contributions. The first is the simple and efficient MM method to eliminate impulsive noise, which can be restricted to a minimum number of pixels. We know the performance of MM is heavily dependent on structuring elements (SEs), but finding an optimal SE is a difficult and nontrivial task. So the second contribution is providing an automatic approach without any experiential parameter for choosing appropriate SEs to eliminate useless components. We have developed a novel algorithm for the binarization of fingerprint images [1]. The information of distance transform values can be obtained directly from the binarization phase. The results show that using this method on fingerprint images with impulsive noise and useless components is faster than existing denoising methods and achieves better quality than earlier methods.

  • A Flexible Connection Model for Software Components

    Hironori WASHIZAKI  Daiki HOSHI  Yoshiaki FUKAZAWA  

     
    PAPER

      Vol:
    E89-D No:4
      Page(s):
    1421-1431

    A component connection enables a component to use the functionality of other components directly, without generating adapters or other mechanisms at run-time. In conventional component connection models, the connection between components, particularly third-party components, is very costly for code reuse because the component source code must be modified if the types of requester-side and provider-side are different. This paper proposes a new component model, built upon an existing component architecture, which abandons a component service type and connects components based on a method type collection of the provider and requester components. Our model enables flexible connections owing to relaxed component matching, in which the system that implements our model automatically converts values of parameters, return values, and exceptions between required methods and provided ones within a well-defined range. As a result of experimental evaluations, it is found that our model is superior to conventional models in terms of the component-use cost and the capability of changing connections.

  • High-Speed MT Connector Assembly Method

    Koji SHIBATA  Masaaki TAKAYA  Kazuo HOGARI  Izumi SANKAWA  Tadashi HAIBARA  

     
    PAPER-Optical Fiber for Communications

      Vol:
    E89-B No:2
      Page(s):
    413-418

    This paper describes a high-speed MT connector assembly method. This technique uses adhesive with a short hardening time, is highly reliable and does not require a polishing process, thus reducing the connector assembly time. First, we investigated an alpha-cyanoacrylate adhesive that hardens quickly and whose adhesive strength does not decrease under high humidity and high temperature conditions, thus ensuring its excellent reliability for outside use. In addition, we investigated variations in the position of the fiber endface on the ferrule endface with a view to obtaining a low insertion loss. Based on the results, we assembled an MT connector using our proposed high-speed assembly method. We confirmed that the assembly time could be reduced to less than 70% of the time required with the conventional method. MT connectors assembled using this technique have a low insertion loss and stable environmental characteristics.

  • Broadband Multi-Way Microstrip Power Dividers

    Mitsuyoshi KISHIHARA  Kuniyoshi YAMANE  Isao OHTA  Tadashi KAWAI  

     
    PAPER

      Vol:
    E88-C No:1
      Page(s):
    20-27

    This paper treats multi-way microstrip power dividers composed of multi-step, multi-furcation, and corners. Since the design procedure is founded on the planar circuit approach in combination with the segmentation method, optimization of the circuit configuration can be performed in a reasonable short computation time when applying the Powell's optimization algorithm. Actually, broadband 3- and 4-way power dividers with mitered bends are designed, and fractional bandwidths of about 90% and 100% are realized for the power-split imbalance less than 0.2 dB and the return loss better than -20 dB, respectively. The validity of the design results is confirmed by an EM-simulator (HFSS) and experiments.

  • Probability Distribution of Time-Series of Speech Spectral Components

    Rajkishore PRASAD  Hiroshi SARUWATARI  Kiyohiro SHIKANO  

     
    PAPER-Audio/Speech Coding

      Vol:
    E87-A No:3
      Page(s):
    584-597

    This paper deals with the statistical modeling of a Time-Frequency Series of Speech (TFSS), obtained by Short-Time Fourier Transform (STFT) analysis of the speech signal picked up by a linear microphone array with two elements. We have attempted to find closer match between the distribution of the TFSS and theoretical distributions like Laplacian Distribution (LD), Gaussian Distribution (GD) and Generalized Gaussian Distribution (GGD) with parameters estimated from the TFSS data. It has been found that GGD provides the best models for real part, imaginary part and polar magnitudes of the time-series of the spectral components. The distribution of the polar magnitude is closer to LD than that of the real and imaginary parts. The distributions of the real and imaginary parts of TFSS correspond to strongly LD. The phase of the TFSS has been found uniformly distributed. The use of GGD based model as PDF in the fixed-point Frequency Domain Independent Component Analysis (FDICA) provides better separation performance and improves convergence speed significantly.

  • Independent Component Analysis (ICA) and Method of Estimating Functions

    Shun-ichi AMARI  

     
    INVITED PAPER-Theories

      Vol:
    E85-A No:3
      Page(s):
    540-547

    Independent component analysis (ICA) is a new method of extracting independent components from multivariate data. It can be applied to various fields such as vision and auditory signal analysis, communication systems, and biomedical and brain engineering. There have been proposed a number of algorithms. The present article shows that most of them use estimating functions from the statistical point of view, and give a unified theory, based on information geometry, to elucidate the efficiency and stability of the algorithms. This gives new efficient adaptive algorithms useful for various problems.

  • Basic Studies of Fiber-Optic MEMS for Telecommunication Using Three Dimensional Micromachining

    Kazuhiro HANE  Minoru SASAKI  JongHyeong SONG  Yohei TAGUCHI  Kosuke MIURA  

     
    PAPER

      Vol:
    E84-C No:12
      Page(s):
    1785-1791

    Fiber-optic MEMS which is fabricated by combining direct photo-lithography of optical fiber and silicon micro-machining is proposed. Preliminary results of micro-machining of optical fiber and variable telecommunication devices are presented.

  • Propagation Characteristics of the Rectangular Waveguide Inhomogeneously Filled with Uniaxial Omega Media

    Antonio L. TOPA  Carlos R. PAIVA  Afonso M. BARBOSA  

     
    PAPER-Passive Devices and Circuits

      Vol:
    E82-C No:7
      Page(s):
    1166-1171

    We address, in this paper, the main features of hybrid modes propagating in a rectangular waveguide partially filled with pseudochiral Ω-slabs. For the particular case of a uniaxial Ω-slab, we show that LSE and LSM hybrid modes can propagate in this inhomogeneously filled rectangular waveguide. The influence of the Ω-parameter, which characterizes the magnetoelectric tensors of the bianisotropic slab, on LSM modes is analyzed--namely an increase in the bandwidth for monomodal operation is reported. In addition, a field displacement effect and a variable phase shift proportional to the change of the Ω-parameter are attained. Finally, it is shown that the propagation characteristics are independent of the direction of propagation and so, unlike the case of magnetically biased ferrite loading, reciprocal devices can be achieved.

  • A Novel Receiver Design for DS-CDMA Systems under Impulsive Radio Noise Environments

    Sakda UNAWONG  Shinichi MIYAMOTO  Norihiko MORINAGA  

     
    PAPER-Radio Communication

      Vol:
    E82-B No:6
      Page(s):
    936-943

    In this paper, we investigate the bit error rate (BER) performance of Direct Sequence-Code Division Multiple Access (DS-CDMA) systems under impulsive radio noise environments, and propose a novel DS-CDMA receiver which is designed to be robust against impulsive noise. At first, employing the Middleton's Class-A impulsive noise model as a typical model of impulsive radio noise, we discuss the statistical characteristics of impulsive radio noise and demonstrate that the quadrature components of impulsive noise are statistically dependent. Next, based on the computer simulation, we evaluate the BER performance of a conventional DS-CDMA system under a Class-A impulsive noise environment, and illustrate that the performance of the conventional DS-CDMA system is drastically degraded by the effects of the impulsive noise. To deal with this problem, motivated by the statistical dependence between the quadrature components of impulsive radio noise, we propose a new DS-CDMA receiver which can eliminate the effects of the channel impulsive noise. The numerical result shows that the performance of the DS-CDMA system under the impulsive noise environment is significantly improved by using this proposed receiver. Finally, to confirm the effectiveness of this proposed receiver against actual impulsive radio noise, we evaluate the BER performance of the DS-CDMA system employing the proposed receiver under a microwave oven (MWO) noise environment and discuss the robustness of the proposed receiver against MWO noise.

  • Process Synthesis Using TCAD: A Mixed-Signal Case Study

    Michael SMAYLING  John RODRIGUEZ  Alister YOUNG  Ichiro FUJII  

     
    INVITED PAPER

      Vol:
    E82-C No:6
      Page(s):
    983-991

    A complex modular process flow was developed for PRISM technology to permit increased system integration. In order to combine the required functions--submicron CMOS Logic, Nonvolatile Memories, Precision Linear, and Power Drivers--on a monolithic silicon chip, a highly structured, systematic approach to process synthesis was developed. TCAD tools were used extensively for process design and verification. The 60 V LDMOS power transistor and the Flash memory cell built in the technology will be described to illustrate the process synthesis methodology.

  • Neural Network Based Photometric Stereo with a Nearby Rotational Moving Light Source

    Yuji IWAHORI  Robert J. WOODHAM  Masahiro OZAKI  Hidekazu TANAKA  Naohiro ISHII  

     
    PAPER-Image Processing,Computer Graphics and Pattern Recognition

      Vol:
    E80-D No:9
      Page(s):
    948-957

    An implementation of photometric stereo is described in which all directions of illumination are close to and rotationally symmetric about the viewing direction. THis has practical value but gives rise to a problem that is numerically ill-conditioned. Ill-conditioning is overcome in two ways. First, many more than the theoretical minimum number of images are acquired. Second, principal components analysis (PCA) is used as a linear preprocessing technique to determine a reduced dimensionality subspace to use as input. The approach is empirical. The ability of a radial basis function (RBF) neural network to do non-parametric functional approximation is exploited. One network maps image irradiance to surface normal. A second network maps surface normal to image irradiance. The two networks are trained using samples from a calibration sphere. Comparison between the actual input and the inversely predicted input is used as a confidence estimate. Results on real data are demonstrated.

  • Switching Converter Using Thin-Film Microtransformer with Monolithically Integrated Rectifier Diodes

    Masato MINO  Toshiaki YACHI  Keiichi YANAGISAWA  Akio TAGO  Kazuhiko SAKAKIBARA  

     
    PAPER-Components

      Vol:
    E80-C No:6
      Page(s):
    821-827

    Our compact switching converter using a thin-film microtransformer mono-lithically integrated with rectifier diodes represents the first step in developing a monolithic micro-switching converter that can be integrated with semiconductor devices and magnetic components. This converter is a single-ended forward converter with resonant reset and operates successfully at 15 MHz. The maximum output power is 0.5 W.

  • Harmonics Estimation Based on Instantaneous Frequency and Its Application to Pitch Determination of Speech

    Toshihiko ABE  Takao KOBAYASHI  Satoshi IMAI  

     
    PAPER-Speech Processing and Acoustics

      Vol:
    E78-D No:9
      Page(s):
    1188-1194

    This paper proposes a technique for estimating the harmonic frequencies based on instantaneous frequency (IF) of speech signals. The main problem is how to decompose the speech signal into the harmonic components. For this purpose, we use a set of bandpass-filters, each of whose center frequencies changes with time in order to track the instantaneous freuency of its output. As a result, the outputs of the band-pass filters become the harmonic components, and the instantaneous frequencies of the harmonics are accurately estimated. To evaluate the effectiveness of the approach, we apply it to pitch determination of speech. Pitch determination is simply accomplished by selecting the correct fundamental frequency out of the harmonic components. It is confirmed that the pitch extraction using the proposed pitch determination algorithm (PDA) is stable and accurate. The most significant feature of the PDA is that the extracted pitch contour is smooth and it requires no post-processing such as nonlinear filtering or any smoothing processes. Several examples are presented to demonstrate the capability of the harmonics estimation technique and the PDA.

  • Automatic Determination of the Number of Mixture Components for Continuous HMMs Based a Uniform Variance Criterion

    Tetsuo KOSAKA  Shigeki SAGAYAMA  

     
    PAPER

      Vol:
    E78-D No:6
      Page(s):
    642-647

    We discuss how to determine automatically the number of mixture components in continuous mixture density HMMs (CHMMs). A notable trend has been the use of CHMMs in recent years. One of the major problems with a CHMM is how to determine its structure, that is, how many mixture components and states it has and its optimal topology. The number of mixture components has been determined heuristically so far. To solve this problem, we first investigate the influence of the number of mixture components on model parameters and the output log likelihood value. As a result, in contrast to the mixture number uniformity" which is applied in conventional approaches to determine the number of mixture components, we propose the principle of distribution size uniformity". An algorithm is introduced for automatically determining the number of mixture components. The performance of this algorithm is shown through recognition experiments involving all Japanese phonemes. Two types of experiments are carried out. One assumes that the number of mixture components for each state is the same within a phonetic model but may vary between states belonging to different phonemes. The other assumes that each state has a variable number of mixture components. These two experiments give better results than the conventional method.

  • Influence of Cross-Sectional Deformation on Coplanar Waveguide Characteristics for the Use of Optical Modulator

    Xiang ZHANG  Tanroku MIYOSHI  

     
    PAPER

      Vol:
    E77-C No:11
      Page(s):
    1766-1770

    In this paper, the influences of the cross-sectional deformation on the coplanar waveguide (CPW) characteristics for the use of Ti: LiNbO3optical modulator are presented based on quasi-static analysis. In particular, the influences of the changes in the thickness of Ti: LiNbO3 substrate and the cross-sectional shape of electrodes are studied in detail by using the finite element method proposed previously. As a result, it is found that the propagation characteristics of the dominant mode change significantly with the thickness of LiNbO3 substrate when it is less than 100 µm. It is also shown that an inverted trapezoidal deformation of the electrode cross section is promising because a wider electrode gap and thinner electrodes are available in the design of optical modulators.

  • High-Density, High-Pin-Count Flexible SMD Connector for High-Speed Data Bus

    Shinichi SASAKI  Tohru KISHIMOTO  

     
    PAPER-Components

      Vol:
    E77-C No:10
      Page(s):
    1694-1701

    This paper describes a high-density, high-pin-count flexible SMD connector used for high-speed data buses between MCMs or daughter boards. This connector consists of a flexible film cable interconnection with accurately controlled characteristic impedance, and a contact housing composed of double-line contacts and SMD type leads. It has 98 contacts each with a pitch of 0.4 mm. The connector mounting area is 6 mm wide and 23 mm long. The flexible cable has a double-sided triple-parallel micro stripline structure with an insertion force of less than 2.9 kgf and characteristic impedance of 48 to 50 Ω. Insertion loss is -0.5 dB at 600 MHz and crosstalk noise is less than 110 mV at 250 ps rising time. This connector can be used for high-speed data transmission of up to 300 ps rising time.

21-40hit(44hit)