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Advance publication (published online immediately after acceptance)

Volume E64 No.5  (Publication Date:1981/05/25)

    Regular Section
  • Encoding and Storage of Contour Maps and Their Application to weather Maps

    Delfin Y. MONTUNO  Yuuji YOSHIDA  Teruo FUKUMURA  

     
    PAPER-Data Processing

      Page(s):
    287-294

    The class of contour map patterns, for example, geographic elevation map and isobar map, is an important class of pictorial data. Its storage and retrieval management have serious implications in the context of a pictorial data bank organization. In this context, we propose the use of the global description of contour map, a string representation called GDCM, for the storage organization of contour maps. We first present a summary of the basic ideas and concepts that leads to the structural description of contour map and then formulate the global description. To take into consideration the frequencies of occurrence of contour clusters (GDCM symbols), we encode the GDCM, which serves as indexes to contour maps, with the Huffman coded GDCM symbols. After organizing the set of encoded GDCM strings into a digital tree for storing the contour maps, we discuss the resulting space and time complexity. We then apply the above ideas to the storage organization of weather maps and evaluate the space and time complexity of the resulting storage structure. The evaluated results indicate that our proposed storage structure for contour map is a viable one.

  • Function Testing of Bipolar and MOS LSI Circuits with a Combined Stroboscopic SEM-Microcomputer System

    Hiromu FUJIOKA  Koji NAKAMAE  Hiroyuki TAKAOKA  Katsumi URA  

     
    PAPER-Semiconductors

      Page(s):
    295-301

    What is required for the functional testing of modern high-density and fast IC and large scale integration (LSI) circuits is a method which has a time resolution in the subnanosecond region and a spatial resolution in the submicrometer region. Furthermore, the test probe must be easy to position on the circuit. To meet these requirements, a combined stroboscopic SEM-microcomputer test system has been developed. A microcomputer is used for striking the electron beam to a point of interest on the specimen surface, sampling and storing the signal waveforms, performing an operation of signal processing, and generating a data display or data output in numerics. Following a system description, application to a MOS LSI (4 k bit static random access memory-RAM) in the MHz regions is reported to demonstrate the efficiency of the system.

  • Evaluation of Diversity Effects on Mobile Radio System Disign

    Masaharu HATA  Kota KINOSHITA  Kenkichi HIRADE  

     
    PAPER-Antenna and Propagation

      Page(s):
    302-308

    A simple method of evaluating diversity effects in the design of land mobile radio systems is introduced, and power reduction and spectrum utilization are discussed. First the processes for determining transmitter power and frequency reuse distance, which are very important factors in system design, are derived. In this derivation, the probability of a fade below a given threshold level and the probability of co-channel interference are calculated for systems operating in Rayleigh fading and lognormal shadowing environments. The probabilities are presented by simple form applicable to system design. Then, based on the derivation, a method of evaluating diversity effects is shown by taking the case of selection diversity. The results show how these effects can be taken into account in system design.

  • Local Curve Fitting Procedures Using Cubic Splines

    Koichi HARADA  Eihachiro NAKAMAE  

     
    PAPER-Computers

      Page(s):
    309-313

    Various calculations of derivatives, dealing with specific spaces, have been studied to define cubic splines. Some Modified 3-Point Methods have been proposed which would reduce the amount of calculations required. These methods enable us to preceive the result from a computer by lines. Some theorems that are useful for the discussion of local calculations are given and examples are executed to compare our methods with the original cubic spline functions. The results given in this paper have demonstrated a relation to the interactive computer graphics as well as the interpolation of data points.

  • Comparison of Convergence Property among Adaptive Arrays

    Masaharu FUJITA  

     
    PAPER-Antenna and Propagation

      Page(s):
    314-318

    Convergence properties of adaptive algorithms are analyzed and compared with mutually by using the differential equation approach. Evaluations of the convergence rates of the algorithms are made by the eigenvalues of matrix coefficient which are relating to the radio environment and the guideline of adaptation. The result shows that the adaptive array under directional constraint is the most applicable to communications for fixed stations or stations in predictable motion despite of its slower convergence rate, because it requires only an approximated information about the desired signal. But, for a desired signal whose incident direction is unknown at the receiver, only the least-mean-square-error adaptive array can extract the desired signal from noisy environment, if a synchronization between the received desired signal and the internal reference signal is kept.

  • Recognition of Hangeul by Means of Structural Analysis

    Byung-Uk CHOI  Tadao ICHIKAWA  Hiroichi FUJITA  

     
    PAPER-Data Processing

      Page(s):
    319-325

    This paper describes a Method of recognizing Hangeul (Korean Characters) which is based on the structural analysis of characters. The experiment results obtained through computer simulation are given. In recognition of Hangeul composed of 24 basic character elements, we pay special attention to regular combinational rules for character formation. The recognition system is composed of three major processing parts: Extraction of character elements, Recognition of each character element and Syntactic reconstruction of a character based on the recognized character elements. The character elements which failed in the syntactic reconstruction are sent back to the character element extraction process again, providing the flexibility to adopt to the more advanced experiments. We first present the structure of Hangeul for feature extraction. Next, some processing algorithms are described and simulated. The experiment results demonstrate the effectiveness of the proposed recognition system.

  • Realizability Condition for Two-Ports Composed of Three Reactance Two-Ports and Two Resistors

    Tetsuo NISHI  

     
    PAPER-Circuit Theory

      Page(s):
    326-333

    This paper shows the necessary and sufficient condition for an admittance matrix to be realized as a network composed of three reactance two-ports and two resistors connected in cascade.

  • An Analysis of Output Characteristics of a Nonlinear Satellite Transponder for Multi-Carrier Systems

    Mazen N. DAHABREH  Norihiko MORINAGA  Toshihiko NAMEKAWA  

     
    PAPER-Transmission Systems

      Page(s):
    334-341

    In multi-carrier satellite communication systems, many modulated carriers have to be co-amplified through a TWTA (Traveling Wave Tube Amplifier). In such a case, the intermodulation due to the TWTA nonlinearities i.e., AM/AM and AM/PM conversions degrades that system performance. This paper analyzes the combined effects of the AM/AM and AM/PM conversions on the output properties of the TWTA using a quadrature nonlinear model. A general formula of the output autocorrelation function is derived as a function of the input autocorrelation function with an arbitrary input power spectrum. Based on this formula, the effects of the TWTA nonlinearities (both AM/AM and AM/PM conversions) on the output characteristics such as the output signal and intermodulation power, the intermodulation power spectral distribution, and the output signal-to-intermodulation ratio (SIMR) are theoretically evaluated.

  • Rotational Byte Error Detecting Codes for Memory Systems

    Eiji FUJIWARA  Shigeo KANEDA  

     
    PAPER-Computers

      Page(s):
    342-349

    Error correcting and/or detecting codes have been successfully used to improve the reliability of computer memories. To improve for error control in memory systems organized to have b bits per package, a new class of linear codes for simultaneous error correction and error detection is given. We refer to a group of b bits as a byte. This paper provides a new type of byte error detecting codes to correct single bit errors and detect single byte errors (SEC-SbED codes), and to correct single bit errors and detect double bit errors and single byte errors (SEC-DED-SbED codes). Form these codes, this paper demonstrates a new class of rotational SEC-SbED codes and rotational SEC-DED-SbED codes that are optimal for LSI construction of their encoding-decoding circuitries. The decoders for the proposed codes require very small amounts of extra circuitry over that required for SEC-DED (Single Error Correcting - Double Error Detecting) codes. The decoding speed is very high-equal to that of SEC-DED codes.

  • The Duo-Multiplication

    Takao NISHITANI  

     
    PAPER-Electronic Circuits

      Page(s):
    350-356

    A novel and efficient multiplication algorithm, called "duo-multiplication", is proposed. Two multiplications and the sum of their results are calculated directly, with the same number of operation steps as is required for the conventional single multiplication. The algorithm is derived from adjusting non-zero partial product generation timing in order to interleave one multiplication execution into the other multiplication execution. This timing adjustment is realized by utilizing the fact that any two algebraic numbers in two's complement representation can be transformed into a binary signed digit representation pair, in which the non-zero digits of one number do not overlap with those of the other number, without increasing total word length. As duomultiplication operation is fundamental on digital signal processing, the algorithm adoption doubles signal processing capability of a microprocessor.

  • Determination of Vanishing Point in Outdoor Scene

    Hiromasa NAKATANI  Tadahiro KITAHASHI  

     
    LETTER-Data Processing

      Page(s):
    357-358

    By the location of a vanishing point of an object in a picture we can determine the spatial relationship between the object and the observer. In this paper we present a technique for determining its location by Hough transformation. As an application we present a method of calculating panned angle of the observer.

  • Electrostatic Drop Forming Characteristics by the Use of a Metal Nozzle

    Takeshi AGUI  Masayuki NAKAJIMA  Masaru INOUE  

     
    LETTER-Electron Devices

      Page(s):
    359-360

    Electrostatic drop forming characteristics of using a metal nozzle are compared with that of using glass nozzles. Taking the surface tension values of liquids as a parameter, we made experiments and concluded that the electroconductivity of liquids has prominent effects on drop formation for low surface tension liquids.