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[Keyword] TE(21534hit)

14121-14140hit(21534hit)

  • Geometrically Invariant Watermarking Based on Gravity Center

    Ke DING  Chen HE  Ling-ge JIANG  Hong-xia WANG  

     
    LETTER-Information Security

      Vol:
    E87-A No:2
      Page(s):
    513-515

    A novel geometrically invariant watermarking scheme based on gravity center is presented which treating the geometrically invariant gravity centers of host image and its supplement image as reference points. Thus watermark synchronization is obtained. Simulation results show the effectiveness of our scheme to the geometrical distortion including rotation and/or scaling.

  • Investigation of Single Monolayer Formation of the Evaporated Liquid Crystalline Molecules by the Surface Potential Measurement

    Takaaki MANAKA  Hajime HIGA  Dai NAKAMURA  Dai TAGUCHI  Mitsumasa IWAMOTO  

     
    LETTER-Nano-interface Controlled Electronic Devices

      Vol:
    E87-C No:2
      Page(s):
    183-184

    The formation of single monolayer of liquid crystalline molecules, 4-n-pentyl-4-cyanobiphenyl (5CB), deposited by the evaporation method in the air, was confirmed with the surface potential measurement. The surface potential increased with the time of evaporation, and the 3- or 4-minute evaporation at a source temperature of 110 gave the saturated potential, indicating the formation of single monolayer. Single monolayer formation was also supported by the comparison of the UV-visible absorption for evaporated film with LB monolayer. Positive potentials were built at the surface, indicating that CN group faces the substrate.

  • Caption Detection Algorithm Using Temporal Information in Video

    Chung-Ho SHIN  Chul-Hyun KWON  Su-Yeon KIM  Sang-Hui PARK  

     
    LETTER-Image Processing, Image Pattern Recognition

      Vol:
    E87-D No:2
      Page(s):
    487-490

    A novel caption text detection and recognition algorithm using the temporal nature of video is proposed in this paper. A text registration technique is used to locate the temporal and spatial positions of captions in video from the accumulated frame difference information. Experimental results show that the proposed method is effective and robust. Also, a high processing speed is achieved since no time consuming operation is included.

  • On Robust Approximate Feedback Linearization

    Ho-Lim CHOI  Jong-Tae LIM  

     
    LETTER-Systems and Control

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

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

  • Content Delivery Platform on ITS Road-Vehicle Communication System Based on Radio over Fiber

    Kiyohito YOSHIHARA  Hiroki HORIUCHI  Fumihide KOJIMA  Katsuyoshi SATO  Masayuki FUJISE  

     
    PAPER-Network

      Vol:
    E87-D No:2
      Page(s):
    426-435

    In this paper, we propose a new content delivery platform on the ITS (Intelligent Transport Systems) road-vehicle communication system on the basis of ROF (Radio over Fiber). The platform is strongly motivated by the ROF communication system capabilities of (1) broadband access, (2) integrated multiple service transmission interface, and (3) simultaneous use of a single and downsized vehicle terminal shared among multiple services based on a multi-mode software radio system. Content is delivered on per reservation basis, as is carefully envisaged as a primary service which is subjected to immaturity of early ITS road-vehicle communication systems, and is provided in limited service areas such as parking on main highways. After the reservation, requested content is stored in a cache connected to a ROF local station via optical fiber. At the designated time, the content is delivered from the cache to a target terminal by way of the ROF local station at high-speed. It can also be done by moving the content from the cache to another cache depending on the target terminal location in a flexible and reliable manner, even if the target terminal could not reach the place at the time designated in the reservation. Such flexibility and reliability are required for consequent practical application, and are provided using information given in the reservations. We implement a preliminary system to evaluate the proposed platform from the viewpoints of (1) processing time from logging into the system for a reservation to delivering content to the target terminal and (2) amount of control traffic required for the delivery. The results show that the proposed platform in which content is delivered from a cache connected with a ROF local station distributed geographically is effective. We also evaluate content delivery throughput using the system connected with an actual ROF local station, and show that the effective throughput is 40 Mbps and the proposed platform is a promising ITS service platform. The paper concludes by discussing future study toward realizing a more promising and practical system.

  • Affine Invariant Partial Shape Matching by means of Unification and Expansion of Local Correspondences

    Hideo OGAWA  

     
    LETTER-Image Processing, Image Pattern Recognition

      Vol:
    E87-D No:2
      Page(s):
    504-508

    This paper describes a novel method of shape matching by means of unification and expansion of local correspondences on the feature points. The method has the ability to simultaneously locate plural similar parts of two-dimensional objects under affine transformation. Furthermore, the method is applicable to the objects partially occluded. Experimental results show that the method yields results that are satisfactory, even for the cases with additions, deletions and local deviations of some feature points.

  • A Novel Contour Description with Expansion Ability Using Extended Fractal Interpolation Functions

    Satoshi UEMURA  Miki HASEYAMA  Hideo KITAJIMA  

     
    PAPER-Image Processing, Image Pattern Recognition

      Vol:
    E87-D No:2
      Page(s):
    453-462

    In this paper, a novel description method of the contour of a shape using extended fractal interpolation functions (EFIFs) is presented. Although the scope of application of traditional FIFs has been limited to cases in which a given signal is represented by a single-valued function, the EFIFs derived by the introduction of a new parameter can describe a multiple-valued signal such as the contour of a shape with a high level of accuracy. Furthermore, the proposed description method possesses the useful property that once a given contour has been modeled by the proposed description method, the shape can be easily expanded at an arbitrary expansion rate. Experimental results show the effectiveness and usefulness of the proposed description method for representing contours.

  • Approximate Counting Scheme for m n Contingency Tables

    Shuji KIJIMA  Tomomi MATSUI  

     
    PAPER

      Vol:
    E87-D No:2
      Page(s):
    308-314

    In this paper, we propose a new counting scheme for m n contingency tables. Our scheme is a modification of Dyer and Greenhill's scheme for two rowed contingency tables. We can estimate not only the sizes of error, but also the sizes of the bias of the number of tables obtained by our scheme, on the assumption that we have an approximate sampler.

  • Evaluation of a Novel Signal Processing Strategy for Cochlear Implant Speech Processors

    Erdenebat DASHTSEREN  Shigeyoshi KITAZAWA  Satoshi IWASAKI  Shinya KIRIYAMA  

     
    PAPER-Medical Engineering

      Vol:
    E87-D No:2
      Page(s):
    463-471

    Our study focuses on an evaluation of a novel speech processing strategy for multi-channel cochlear implant speech processors. Stimulation pulse trains for the Nucleus 24CI speech processor were generated in a way different from the speech processing strategies implemented in this processor. The distinctive features of the novel strategy are: 1) electrode stimulation order driven by location of maximum instantaneous frequency amplitude; 2) variable stimulation rates on electrodes; 3) variable number of selected channels within a cycle of signal processing schema. Within-subject designed tests on Japanese initial, medial and final consonants in CV, VCV and CV/N context tokens were carried out with cochlear implant patients using the Cochlear ACETM strategy, and results were compared with those of normal hearing listeners. Results of the initial and medial consonant tests showed significantly better performance with the novel strategy than with the ACE strategy for both the cochlear implant and normal hearing listener groups. Results of the final consonant tests showed a slightly better performance with the ACE strategy for cochlear implant listeners while showing a slightly better performance with the novel strategy for normal hearing listeners.

  • A Flexible Distributed Computing System and Its Application for Signal Processing

    Zhihui WANG  Tohru KIRYU  Keisuke SHIBAI  Shinkichi SAKAHASHI  

     
    LETTER-Medical Engineering

      Vol:
    E87-D No:2
      Page(s):
    509-512

    In this paper, we present a flexible distributed computing system in which it is very easy to add required computing components at any time. The system is an Internet-based solution, and mainly developed by Java and XML. Moreover, by implementing a new configuration of computing information that is setting up Public Information and Private Information, the system can accommodate various computing requests, and facilitate a flexible design. Additionally, to show the practical merit, as an example of signal processing, we presented how to apply our proposed system to selection of a suitable artificial neural network.

  • Design of Channel Estimation Filters for Pilot Channel Based DS-CDMA Systems

    Ji-Woong CHOI  Yong-Hwan LEE  

     
    PAPER-Wireless Communication Technology

      Vol:
    E87-B No:2
      Page(s):
    227-233

    The accuracy of channel estimation significantly affects the performance of coherent receiver in a DS-CDMA system. The receiver performance can be improved if an appropriate channel estimation filter is used according to the channel condition. In this paper, we consider the design of channel estimation filters for pilot channel based DS-CDMA systems. When a moving average (MA) FIR filter is used as the channel estimation filter (CEF), the tap size is optimized by minimizing the mean squared error of the estimated channel impulse response. Finally, the analytic design is verified by computer simulation. Numerical results show that the optimum MA FIR CEF provides near optimum performance, i.e., quite similar to that with the use of Wiener filter.

  • AFM/STM Observation of C-Au-S Conductive Granular Molecule by Co-operation Process of Plasma CVD and Sputtering

    Mikinori SUZUKI  Md. Abul KASHEM  Shinzo MORITA  

     
    PAPER-Organic-neuro Systems

      Vol:
    E87-C No:2
      Page(s):
    179-182

    AFM/STM observations were performed on sub nm thick C-Au-S film by co-operation process of plasma CVD and sputtering with using CH4, SF6 and Ar mixture gas and Au plate discharge electrode. From the refractive index values, the conductive granular molecules with a size of 0.4-0.6 nm were expected to exist in the film. For the film at thickness similar to the molecular size, Ra (arithmetic mean departures of roughness profile from the mean line) values were measured to be 0.712/6.10 nm by AFM/STM measurement, respectively. The one order large STM Ra value compared to the AFM Ra value suggests that the film contains conductive granular molecules.

  • Preparation of Cuprous Oxide (Cu2O) Thin Films by Reactive DC Magnetron Sputtering

    Kiichi KAMIMURA  Haruki SANO  Katsuya ABE  Rinpei HAYASHIBE  Tomohiko YAMAKAMI  Masato NAKAO  Yoshiharu ONUMA  

     
    PAPER

      Vol:
    E87-C No:2
      Page(s):
    193-196

    Cuprous Oxide Cu2O films were deposited by reactive DC magnetron sputtering. The substrate temperature and oxygen partial pressure were found to be important parameters in controlling the film property. The single-phase Cu2O films were successfully obtained by carefully controlling the oxygen partial pressure with suppression of CuO formation. The (100)-oriented epitaxial Cu2O film was grown on the (102) surface of single-crystal Al2O3. The fundamental absorption edge of the Cu2O film was determined to be about 2 eV by photo-transmission measurement. The resistivity of the film was of the order of 105 Ωcm.

  • Low Temperature Deposition of Indium Tin Oxide Thin Films by Low Voltage Sputtering in Various Rare Gases

    Yoichi HOSHI  Hidehiko SHIMIZU  

     
    PAPER

      Vol:
    E87-C No:2
      Page(s):
    212-217

    Indium tin oxide (ITO) films were deposited at a temperature below 50 by a low-voltage sputtering system. The sputtering voltage was fixed at 100 V and Ar, Kr, and Xe were used as the sputtering gases. Compared with the sputtering in Ar gas, the sputtering in Kr or Xe gas caused a significant suppression of crystallization of the deposited film and resulted in the formation of amorphous films. These films had much lower resistivities than the films deposited using Ar gas, since the Hall mobility of the films had a larger value. Typical Hall mobility and carrier density are 50 cm2/Vsec, and 51020 cm-3, respectively. This improvement was attributable to the reduction of high-energy particle bombardment to the film surface in the sputtering. These films are stable at a temperature below 150, and crystallization occurs at a temperature above 150.

  • Crystallization and Conductivity of ReO3 Thin Films Prepared by 90Off-Axis RF Magnetron Sputtering Method

    Nobuyuki IWATA  Kumiko FUKAI  Hiroshi YAMAMOTO  

     
    PAPER

      Vol:
    E87-C No:2
      Page(s):
    223-226

    We investigated growth conditions of the ReO3 thin films, as a first step of establishment of artificial superconducting multi-layer with the infinite layer cuprate and ReO3. The layers of ReO3 were expected to work as a charge reservoir block. The films were deposited from a Re metal target by off-axis reactive sputtering. Conductive and preferentially (100) oriented ReO3 thin films were obtained by in-situ post-annealing. The lowest resistivity was 4.4 10-5 ohmcm at room temperature.

  • Superconducting Properties of EuBa2Cu3O7 Thin Films Deposited on R-Plane Sapphires with CeO2Sm2O3 Buffer Layers Using Magnetron Sputtering

    Osamu MICHIKAMI  Yasuyuki OTA  Shinji KIKUCHI  

     
    PAPER

      Vol:
    E87-C No:2
      Page(s):
    197-201

    In order to improve the critical current density (Jc) of c-axis-oriented EuBa2Cu3O7 (c-EBCO) thin films deposited on R-plane sapphires (R-Al2O3) with a CeO2 buffer layer, insertion of an Sm2O3 buffer layer and optimization of its deposition condition were attempted. The effects of substrate temperature and film thickness of an Sm2O3 buffer layer on the orientation, crystallinity, surface morphology and superconducting properties of EBCO thin films were examined. As a result, EBCO thin films with Jc = 5.7 MA/cm2 at 77.3 K were obtained on a sapphire with a CeO2(80 )Sm2O3(200 ) buffer layer. Epitaxial relations of sputter-deposited films were clarified.

  • High Rate Sputter-Deposition of TiO2 Films Using Oxide Target

    Yoichi HOSHI  Tomoki TAKAHASHI  

     
    PAPER

      Vol:
    E87-C No:2
      Page(s):
    227-231

    The sputter-deposition process of TiO2 thin films was investigated. When an oxide target is used, high-rate deposition above 57 nm/min can be realized by sputtering under a condition of low oxygen gas content. Under this sputtering condition, a Ti rich surface layer is formed by selective sputtering of oxygen atoms, and a large amount of Ti atoms are sputtered from this layer. The deposition rate, however, decreases steeply as the oxygen gas content increases. This decrease can be explained as follows. When a sufficient amount of oxygen gas is supplied into the chamber during sputtering, the oxygen atoms which are missing from the target surface by selective sputtering are filled up immediately. This leads to a very low deposition rate of the film, because only oxygen atoms are sputtered from the target. Therefore, the suppression of the incidence of oxygen gas to the target surface and a sufficient of oxygen supply to the substrate are necessary to realize the high-rate deposition of stoichiometric TiO2 films. From this point of view, using an oxide target instead of a metal target is useful for realizing a stable high-rate deposition of the film, since the amount of oxygen gas introduced in to the sputtering chamber can be reduced significantly. In addition, it was confirmed that pulse sputtering method is a useful technique for the deposition of TiO2 thin films. Meanwhile, low-voltage sputtering technique was difficult to use for the film deposition because of its low deposition rate.

  • A Semi-Adaptive MMSE Weights Generation Approach for Ordered Successive Detection in MIMO Systems

    Anass BENJEBBOUR  Susumu YOSHIDA  

     
    PAPER-Wireless Communication Technology

      Vol:
    E87-B No:2
      Page(s):
    276-285

    To increase the spectral utilization efficiency of a wireless link, multiple-input multiple-output (MIMO) systems can be employed to transmit several data streams in parallel at the same time and on the same frequency but from different transmit antennas. However, at the receiver side multi-stream detection is needed. In this paper, ordered successive MMSE detection (OSD) is considered as a low-complexity detection scheme. OSD's main computational cost lies in computing the nulling weights that correspond to each stage of successive detection. In this paper, we develop an efficient semi-adaptive approach to generate MMSE weights. This semi-adaptive approach efficiently combines two approaches: channel estimates-based direct matrix inversion weights generation (direct approach) and Recursive Least Squares (RLS) algorithm-based weights generation (adaptive approach). Although the direct approach alone performs better than the adaptive approach, it is more complex for updating weights within the tracking mode. On the other hand, the adaptive approach alone is less complex in updating weights within the tracking mode, but converges slowly within the training mode. Our combined semi-adaptive approach effectively offsets these disadvantages. We demonstrate, through computer simulations, that the semi-adaptive approach can achieve the BER of the direct approach in slow time-varying MIMO channels, while its computational complexity is less than or comparable to that of the adaptive approach.

  • Iterative Decoding of Serially Concatenated Space-Time Codes in WCDMA Systems with Short Frames

    Bon-Jin KU  Jong-Moon CHUNG  Changeon KANG  

     
    LETTER-Wireless Communication Technology

      Vol:
    E87-B No:2
      Page(s):
    357-359

    In this letter, we investigate serially concatenated space-time codes (SC-STs) applying iterative decoding topologies in wideband code division multiple access (WCDMA) communication systems. In the decoding algorithm, an iterative (turbo) process is used, where a priori probability (APP) is exchanged between the symbol-by-symbol space-time (ST) decoder and the bit-by-bit convolutional decoder. The experimental results show that in a Rayleigh fading channel environment the serially concatenated interleaved space-time coding systems show significant error correction capability, and based on the applied system configurations, the nonrecursive ST code outperforms the recursive ST code.

  • High-Rate Deposition of Titanium Dioxide Films with Photocatalytic Activities by Gas Flow Sputtering

    Kiyoshi ISHII  Kazunari KUROKAWA  Sachio YOSHIHARA  

     
    PAPER

      Vol:
    E87-C No:2
      Page(s):
    232-237

    Photocatalytic TiO2 films were prepared by reactive gas flow sputtering (GFS), which enables sputter-deposition at a high pressure of about 100 Pa. A pure Ti tube was used as the target, and the O2 gas was supplied in front of the substrate, resulting in a very stable discharge and a high deposition rate of 80 nm/min. The crystal structure and morphology of TiO2 films were found to strongly depend on the flow rate of O2 gas during sputtering. Polycrystalline films composed of rutile and anatase crystallites were deposited at a low O2 flow rate of less than 2 sccm when Ar flow rate was set at 300 sccm, and amorphous films were deposited at higher O2 flow rates. Polycrystalline films composed of very small crystallites showed high levels of photocatalytic activity, while amorphous films showed no activity.

14121-14140hit(21534hit)