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921-940hit(1110hit)

  • Modelling Integer Programming with Logic: Language and Implementation

    Qiang LI  Yike GUO  Tetsuo IDA  

     
    PAPER-Numerical Analysis and Optimization

      Vol:
    E83-A No:8
      Page(s):
    1673-1680

    The classical algebraic modelling approach for integer programming (IP) is not suitable for some real world IP problems, since the algebraic formulations allow only for the description of mathematical relations, not logical relations. In this paper, we present a language + for IP, in which we write logical specification of an IP problem. + is a language based on the predicate logic, but is extended with meta predicates such as at_least(m,S), where m is a non-negative integer, meaning that at least m predicates in the set S of formulas hold. The meta predicates facilitate reasoning about a model of an IP problem rigorously and logically. + is executable in the sense that formulas in + are mechanically translated into a set of mathematical formulas, called IP formulas, which most of existing IP solvers accept. We give a systematic method for translating formulas in + to IP formulas. The translation is rigorously defined, verified and implemented in Mathematica 3.0. Our work follows the approach of McKinnon and Williams, and elaborated the language in that (1) it is rigorously defined, (2) transformation to IP formulas is more optimised and verified, and (3) the transformation is completely given in Mathematica 3.0 and is integrated into IP solving environment as a tool for IP.

  • A New Image Sensor with Space Variant Sampling Control on a Focal Plane

    Yasuhiro OHTSUKA  Takayuki HAMAMOTO  Kiyoharu AIZAWA  

     
    PAPER

      Vol:
    E83-D No:7
      Page(s):
    1331-1337

    We propose a new sampling control system on image sensor array. Contrary to the random access pixels, the proposed sensor is able to read out spatially variant sampled pixels at high speed, without inputting pixel address for each access. The sampling positions can be changed dynamically by rewriting the sampling position memory. The proposed sensor has a memory array that stores the sampling positions. It can achieve any spatially varying sampling patterns. A prototype of 64 64 pixels are fabricated under 0.7 µm CMOS precess.

  • C-S Thin Films Formed by Plasma CVD

    Masaki MATSUSHITA  Md. Abul KASHEM  Shinzo MORITA  

     
    PAPER-Thin Film

      Vol:
    E83-C No:7
      Page(s):
    1134-1138

    Thin films of carbon (C)-sulfur (S) compound were formed by plasma CVD (PCVD) at the special chemical condition. The reactor has a parallel plate electrode system and was operated at a discharge frequency of 13.56 MHz with using a mixture gas of argon (Ar), methane (CH4) and SF6. The deposition was performed on a substrate placed on the grounded electrode. Atomic composition of the film was observed to depend on the gas mixture ratio. The sulfur atom density was increased up to 30% with using a mixture gas at a pressure of 0.1 Torr and at a flow rate of 20, 20 and 50 SCCM for Ar, CH4 and SF6, respectively. It was expected that the C-S compounds were deposited under the condition of F atom elimination by forming HF.

  • Fabrication of Coplanar Microstructures Composed of Multiple Organosilane Self-Assembled Monolayers

    Hiroyuki SUGIMURA  Atsushi HOZUMI  Osamu TAKAI  

     
    PAPER-Ultra Thin Film

      Vol:
    E83-C No:7
      Page(s):
    1099-1103

    Micropatterning of organosilane self-assembled monolayers (SAMs) was demonstrated on the basis of photolithography using an excimer lamp radiating vacuum ultra-violet (VUV) light of 172 nm in wavelength. This lithography is generally applicable to micropatterning of organic thin films including alkyl and fluoroalkyl SAMs, since its patterning mechanism involves cleavage of C-C bonds in organic molecules and subsequent decomposition of the molecules. In this study, SAMs were prepared on Si substrates covered with native oxide by chemical vapor deposition in which an alkylsilane, that is, octadecyltrimethoxysilane [CH3(CH2)17Si(OCH3)3, ODS] or a fluoroalkylsilane, that is, 1H, 1H, 2H, 2H-perfluorodecyltrimethoxy-silane [CF3(CF2)7CH2CH2Si(OCH3)3, FAS] were used as precursors. Each of these SAMs was photoirradiated through a photomask placed on its surface. As confirmed by atomic force microscopy and x-ray photoelectron spectroscopy, the SAMs were decomposed and removed in the photoirradiated area while the masked areas remained undecomposed. A micropattern of 2 µm in width was successfully fabricated. Furthermore, microstructures composed of two different SAMs, that is, ODS and FAS, were fabricated as follows. For example, an ODS-SAM was first micropatterned by the VUV-lithography. Since, the VUV-exposed region on the ODS-SAM showed an affinity to the chemisorption of organosilane molecules, the second SAM, i. e. , FAS, confined to the photolithographically defined pattern was successfully fabricated. Due to the electron negativity of F atoms, the FAS covered region showed a more negative surface potential than that of the ODS surface: its potential difference was ca. 120 mV as observed by Kelvin probe force microscopy.

  • Theoretical Analysis on the Performance of Optimal Combining for Multipath Waves Distributed in Spatial and Time Domains

    Takashi INOUE  Yoshio KARASAWA  

     
    PAPER-Wireless Communication Technology

      Vol:
    E83-B No:7
      Page(s):
    1426-1434

    This paper theoretically analyzed the performance of the RAKE combining (in the time domain), maximal ratio combining (in the spatial domain), and two-dimensional RAKE combining (in the spatial and time domains) techniques for multipath fading environments, where multipath waves are distributed in the spatial and time domains. The analysis was based on a diversity combining technique that employed the eigenvalues of the covariance matrix between branch signals. It was found that the performance of the fading mitigation was normalized by the beamwidth of an array antenna, for various parameters such as the number of antenna elements, angular spread, and angle of arrival.

  • Deposition of Polymeric Thin Films by Ionization-Assisted Method

    Hiroaki USUI  

     
    INVITED PAPER-Thin Film

      Vol:
    E83-C No:7
      Page(s):
    1128-1133

    Polymeric thin films can be prepared by physical vapor deposition in several manners such as direct evaporation of the polymer, co-evaporation of two monomers followed by polyaddition or polycondensation reaction, or evaporation of single monomer followed by chain polymerization. The ionization-assisted deposition (IAD) was proposed as a new method of polymer deposition that has special features such as activation of polymerization reaction and aligning of the dipole orientation. These mechanisms were utilized for the formation of vinyl polymer and polyurea thin films aiming for such applications as organic light emitting diodes and piezoelectric devices.

  • A Reconfiguration Algorithm for Memory Arrays Containing Faulty Spares

    Keiichi HANDA  Kazuhito HARUKI  

     
    PAPER

      Vol:
    E83-A No:6
      Page(s):
    1123-1130

    Reconfiguration of memory arrays using spare lines is known to be an NP-complete problem. In this paper, we present an algorithm that reconfigures a memory array without any faults by using spare lines effectively even if they contain faulty elements. First, the reconfiguration problem is transformed to an equivalent covering problem in which faulty elements are covered by imaginary fault-free spare lines. Next, the covering problem is heuristically solved by using the Dulmange-Mendelsohn decomposition. The experiments for recently designed memory arrays show that the proposed algorithm is fast and practical.

  • Verification of a Microcomputer Program Specification Embedded in a Reactive System

    Yasunori ISHIHARA  Kiichiro NINOMIYA  Hiroyuki SEKI  Daisuke TAKAHARA  Yutaka YAMADA  Shigesada OMOTO  

     
    PAPER-Software Engineering

      Vol:
    E83-D No:5
      Page(s):
    1082-1091

    This paper proposes a model checking method for microcomputer programs. To deal with the state explosion problem, we adopt a compositional verification approach. Based on the proposed method, a microcomputer program for a real-life air-conditioner is verified. The program is large enough to cause state explosion. Among fourteen typical properties of the program, five properties are successfully verified by our method.

  • Crossbar Arbiter Architecture for High-Speed MAPOS Switch

    Tsuyoshi OGURA  Satoru YAGI  Tetsuo KAWANO  Mitsuru MARUYAMA  Naohisa TAKAHASHI  

     
    PAPER

      Vol:
    E83-D No:5
      Page(s):
    1028-1038

    This paper describes a crossbar-switch arbiter for a high-speed MAPOS switch. The arbiter uses the following techniques suitable for variable-length frame switching: 1. parallel processing for handling requests from network interfaces and for resource allocation, 2. techniques such as release-on-request, fast back-to-back transfer, and request prefetching to reduce the arbitration overhead, and 3. a resource sampling technique to enable efficient one-shot multicast processing. Our simulation-based performance evaluation and estimation of the scale of its logic circuits indicated that this arbiter can be implemented through simple hardware.

  • A Naming, Storage, and Retrieval Model for Software Assets

    Yuen-Chang SUN  Chin-Laung LEI  

     
    PAPER-Software Systems

      Vol:
    E83-D No:4
      Page(s):
    789-796

    This paper presents a model for the naming, packing, version control, storage, and retrieval of software assets. The naming and version control schemes are based on content-derived coding of the asset body. The name-to-asset mapping can be fixed or be varying with time. The packing scheme is designed so that the asset integrity verification and authentication information is made an intrinsic part of the packed asset. A comparison with an existing naming and version control scheme is given. The storage and retrieval scheme is a unification of four most commonly used methods, namely the enumerative method, the keyword-based method, the faceted method, and the text-based method. This unification makes it possible for the users to access heterogeneous repositories (with different storage and retrieval methods) simultaneously, using the same tool set and query syntax. The degradation functions technique is used to automatically broaden queries. A demonstrative retrieval tool is described to show how the unification of methods is done at the user interface level.

  • Creating Virtual Environment Based on Video Data with Forward Motion

    Xiaohua ZHANG  Hiroki TAKAHASHI  Masayuki NAKAJIMA  

     
    PAPER-Multimedia Pattern Processing

      Vol:
    E83-D No:4
      Page(s):
    931-936

    The construction of photo-realistic 3D scenes from video data is an active and competitive area of research in the fields of computer vision, image processing and computer graphics. In this paper we address our recent work in this area. Unlike most methods of 3D scene construction, we consider the generation of virtual environments from video sequence with a video-cam's forward motion. Each frame is decomposed into sub-images, which are registered correspondingly using the Levenberg-Marquardt iterative algorithm to estimate motion parameters. The registered sub-images are correspondingly pasted together to form a pseudo-3D space. By controlling the position and direction, the virtual camera can walk through this virtual space to generate novel 2D views to acquire an immersive impression. Even if the virtual camera goes deep into this virtual environment, it can still obtain a novel view while maintaining relatively high resolution.

  • Gaze Point Detection by Computing the 3D Positions and 3D Motion of Face

    Kang Ryoung PARK  Jaihie KIM  

    This paper was deleted on March 10, 2006 because it was found to be a duplicate submission (see details in the pdf file).
     
    PAPER-Image Processing, Image Pattern Recognition

      Vol:
    E83-D No:4
      Page(s):
    884-894

    Gaze detection is to locate the position on a monitor screen where a user is looking. In our work, we implement it with a computer vision system setting a single camera above a monitor and a user moves (rotates and/or translates) her face to gaze at a different position on the monitor. For our case, the user is requested not to move pupils of her eyes when she gazes at a different position on the monitor screen, though we are working on to relax this restriction. To detect the gaze position, we extract facial features (both eyes, nostrils and lip corners) automatically in 2D camera images. From the movement of feature points detected in starting images, we can compute the initial 3D positions of those features by recursive estimation algorithm. Then, when a user moves her head in order to gaze at one position on a monitor, the moved 3D positions of those features can be computed from 3D motion estimation by Iterative Extended Kalman Filter (IEKF) and affine transform. Finally, the gaze position on a monitor is computed from the normal vector of the plane determined by those moved 3D positions of features. Especially, in order to obtain the exact 3D positions of initial feature points, we unify three coordinate systems (face, monitor and camera coordinate system) based on perspective transformation. As experimental results, the 3D position estimation error of initial feature points, which is the RMS error between the estimated initial 3D feature positions and the real positions (measured by 3D position tracker sensor) is about 1.28 cm (0.75 cm in X axis, 0.85 cm in Y axis, 0.6 cm in Z axis) and the 3D motion estimation errors of feature points by Iterative Extended Kalman Filter (IEKF) are about 2.8 degrees and 1.21 cm in rotation and translation, respectively. From that, we can obtain the gaze position on a monitor (17 inches) and the gaze position accuracy between the calculated positions and the real ones is about 2.06 inches of RMS error.

  • Knowledge-Based Software Composition Using Rough Set Theory

    Yoshiyuki SHINKAWA  Masao J. MATSUMOTO  

     
    PAPER-Theory and Methodology

      Vol:
    E83-D No:4
      Page(s):
    691-700

    Software Composition is one of the major concerns in component based software development (CBSD). In this paper, we present a formal approach to construct software systems from requirements models using available components. We focus on the knowledge resides in the requirements and the components in order to deal with those heterogeneous concepts. This approach consists of three steps. The first step is selecting adaptable components to the requirements model. The requirements and the components are transformed into the form of Σ algebra, and the component adaptability is evaluated by Σ homomorphism. Rough Set Theory (RST) is used to make carriers of two Σ algebras common, which are derived from the requirements and the components. The second step is identifying the control structure of the requirements. Decision tables are used for representing the knowledge on the requirements, and RST is used to optimize the control structure. The third step is to implement the control structure as glue codes which would perform the components appropriately. This approach mainly focuses on enterprise back-office applications in this paper, however, it can be easily applied to other domains, since it assumes the requirements to be expressed in Colored Petri Nets (CPN), and CPN can express various problem domains other than enterprise back-office applications.

  • Weatherability of 60 GHz Wave Absorber Using Epoxy-Modified Urethane Rubber Mixed with Carbon Particles

    Tetsu SOH  Kouji WADA  Osamu HASHIMOTO  

     
    PAPER-Microwaves, Millimeter-Waves

      Vol:
    E83-C No:3
      Page(s):
    496-501

    An epoxy-modified urethane rubber mixed with carbon particles is now chosen as the millimeter-wave absorber material in our study. The absorption characteristics of the absorber is measured under temperature changes. The weatherability of our absorber is also clarified based on absorption characteristics, thickness and hardness of the sample. As a result of the temperature characteristics of the absorber, the difference of the maximum absorption frequency under temperature changes is about 1 GHz, however the absorption of 20 dB or more is obtained between 54 and 58 GHz. The result of accelerated artificial exposure test is that 2.8% of the thickness of our sample is shrunk after 1000 hour exposure, and the hardness of rubber is hardened with increasing test time. It is also confirmed that the deterioration of the absorption ranges from 1 to 3 dB, although the absorption of about 20 dB is kept at the frequency range. As a consequence, it is confirmed that the wave absorber using the epoxy-modified urethane rubber mixed with carbon particles has good weatherability including our desired temperature characteristics, and it is suitable for outdoor use.

  • All Discrete-Time Positive Real Functions Interpolating Input-Output Characteristics

    Kazumi HORIGUCHI  

     
    PAPER-Systems and Control

      Vol:
    E83-A No:3
      Page(s):
    507-515

    It is an important problem in signal processing, system realization and system identification to find linear discrete-time systems which are consistent with given covariance parameters. This problem is formulated as a problem of finding discrete-time positive real functions which interpolate given covariance parameters. Among various solutions to the problem, a recent remarkable one is a parameterization of all the discrete-time strictly positive real functions that interpolate the covariance parameters and have a limited McMillan degree. In this paper, we use more general input-output characteristics than covariance parameters and consider finding discrete-time positive real functions which interpolate such characteristics. The input-output characteristics are given by the coefficients of the Taylor series at some complex points in the open unit disk. Based on our previous work, we present an algorithm to generate all the discrete-time positive real functions that interpolate the input-output characteristics and have a limited McMillan degree. The algorithm is more general and simpler than the previous one, and is an important practical supplement to the previous work. Moreover, the interpolation of the general input-output characteristics can be effectively applied to the frequency-weighted model reduction. Hence, the algorithm makes a contribution to the problem from the practical viewpoint as well as the theoretical viewpoint.

  • An Optical Fiber Sensor for the Measurement of Elevated Temperatures

    Theodore F. MORSE  Yifei HE  Fei LUO  

     
    PAPER-Physical and Mechanical Sensors

      Vol:
    E83-C No:3
      Page(s):
    298-302

    A novel optical technique for the measurement of temperature is proposed. This is accomplished by depositing alternating 1/4 wave layers of silicon nitride and silicon-rich silicon nitride at the end of an optical fiber. These layers of alternating refractive index form the equivalent of a Bragg grating of a high temperature material. When the fiber and the Bragg grating are heated, the Bragg stack expands, and there is a change in the reflective peak wavelength of this wave stack. Thus, the wavelength of peak reflectivity is a function of temperature. Currently, the 15 nm spectral width of the Bragg stacks is achieved in our laboratory, which is conveniently monitored with a CCD solid state spectrometer and the temperature sensor probes can be also multiplexed at separated specific reflection wavelength. In the experiment, the temperatures in excess of 1,100 centigrade have been measured with a resolution of less than 3 centigrade degree.

  • Reduction Method of Voltage Fluctuation of DC Power Supply in Digital IC

    Tadaharu AKINO  Yasuhiro ONO  Shinichi SHINOHARA  Risaburo SATO  

     
    LETTER

      Vol:
    E83-B No:3
      Page(s):
    622-625

    This paper describes how voltage fluctuation in the DC power supply of a digital IC can be reduced, by means of molding the package-pin in a ferrite-resin composite. The voltage fluctuation of the DC power supply, when the input terminal was driven by a 40 MHz, 5 Vp-p pulse wave, was measured using an oscilloscope. Simultaneously, the voltage spectrum of the fluctuation was measured using a spectrum analyzer. As a result, the voltage fluctuation was decreased by about 50 % when the IC package-pins were molded in a ferrite-resin composite, in which the µiac of the ferrite powder equalled 100, and the powder content was 80 weight-%. In the same IC, there was the reduction effect of the voltage spectrum of the fluctuation was recognized in the frequency range 40 MHz to 1 GHz.

  • A Nonlinear Multiple Complex Sinusoidal Estimator

    Kiyoshi NISHIYAMA  

     
    PAPER-Digital Signal Processing

      Vol:
    E83-A No:3
      Page(s):
    497-506

    A nonlinear multiple complex sinusoidal estimator (NMSE) is proposed, as an extended and improved version with system noise of the single sinusoidal estimator previously presented by the author, for extracting multiple complex sinusoids in white noise. This estimator is derived by applying an extended complex Kalman filter (ECKF) to a noisy multiple complex sinusoidal model with state-representation, where the model becomes a nonlinear stochastic system. Proof of the stability is given by using a structure of the state-space signal model and Lyapunov techniques. Also, computer simulations demonstrate the effectiveness of the NMSE from various points of view.

  • On the Impossibility of Non-blocking Consistent Causal Recovery

    Byoungjoo LEE  Taesoon PARK  Heon Y. YEOM  Yookun CHO  

     
    LETTER-Fault Tolerance

      Vol:
    E83-D No:2
      Page(s):
    291-294

    Causal message logging has many benefits such as nonblocking message logging and no rollback propagation. In this paper, we consider the problem of the recovery in causally-logged distributed system and give a condition for consistent recovery. We then show that, based on the impossibility of the consensus, the consistent causal recovery cannot be solved in asynchronous systems.

  • Data-Parallel Volume Rendering with Adaptive Volume Subdivision

    Kentaro SANO  Hiroyuki KITAJIMA  Hiroaki KOBAYASHI  Tadao NAKAMURA  

     
    PAPER-Computer Graphics

      Vol:
    E83-D No:1
      Page(s):
    80-89

    A data-parallel processing approach is promising for real-time volume rendering because of the massive parallelism in volume rendering. In data-parallel volume rendering, local results processing elements(PEs) generate from allocated subvolumes are integrated to form a final image. Generally, the integration causes an overhead unavoidable in data-parallel volume rendering due to communications among PEs. This paper proposes a data-parallel shear-warp volume rendering algorithm combined with an adaptive volume subdivision method to reduce the communication overhead and improve processing efficiency. We implement the parallel algorithm on a message-passing multiprocessor system for performance evaluation. The experimental results show that the adaptive volume subdivision method can reduce the overhead and achieve higher efficiency compared with a conventional slab subdivision method.

921-940hit(1110hit)