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1361-1376hit(1376hit)

  • Telegraphist's Equations of an E-Plane Taper of a Rectangular Waveguide

    Masao KODAMA  

     
    LETTER-Electromagnetic Theory

      Vol:
    E75-C No:8
      Page(s):
    957-959

    Generalized telegraphist's equations for waveguides are frequently used for analyzing fields in tapered rectangular waveguides. However, the telegraphist's equations do not give exact fields in E-plane tapers of the rectangular waveguides. In this letter, the new telegraphist's equations are shown, and the equations give the fields which exactly satisfy Maxwell's equations and the boundary conditions for the E-plane taper of the waveguide.

  • Subband Image Coding with Biorthogonal Wavelets

    Cha Keon CHEONG  Kiyoharu AIZAWA  Takahiro SAITO  Mitsutoshi HATORI  

     
    PAPER-Image Coding and Compression

      Vol:
    E75-A No:7
      Page(s):
    871-881

    In this paper, subband image coding with symmetric biorthogonal wavelet filters is studied. In order to implement the symmetric biorthogonal wavelet basis, we use the Laplacian Pyramid Model (LPM) and the trigonometric polynomial solution method. These symmetric biorthogonal wavelet basis are used to form filters in each subband. Also coefficients of the filter are optimized with respect to the coding efficiency. From this optimization, we show that the values of a in the LPM generating kernel have the best coding efficiency in the range of 0.7 to 0.75. We also present an optimal bit allocation method based on considerations of the reconstruction filter characteristics. The step size of each subband uniform quantizer is determined by using this bit allocation method. The coding efficiency of the symmetric biorthogonal wavelet filter is compared with those of other filters: QMF, SSKF and Orthonormal wavelet filter. Simulation results demonstrate that the symmetric biorthogonal wavelet filter is useful as a basic means for image analysis/synthesis filters and can give better coding efficiency than other filters.

  • Practical Network Planning Support System--PIGEON

    Atsushi MINEGISHI  Yoshihiro DOI  Hikaru MIYAMOTO  

     
    PAPER

      Vol:
    E75-B No:7
      Page(s):
    601-608

    This paper discusses a computer-aided network planning support system called PIGEON that has been developed primarily for advancing countries implementing the applicability to various types of networks and the supportability to the sensitivity analysis. For the implementation of the applicability, the customization by reflecting existing network facilities and their accompanying restrictive conditions into a design result is focused. A case study on the customization shows the effectiveness of the reflection. The procedures are given of the sensitivity analysis in order to examine and to evaluate the effect of the uncertain factors in network planning. In particular, a method called "network modification" is proposed for the sensitivity analysis for uncertain factors associated with a partial network. The network modification efficiently integrates network planner's judgments into a design result by the interactive method. In addition, this paper describes the importance of streamlining the data input and the evaluation of design results, showing the operating time required for each work phase in network planning.

  • Network Planning of NTT

    Toshiharu AOKI  

     
    INVITED PAPER

      Vol:
    E75-B No:7
      Page(s):
    541-549

    Network planning for a public switched telephone network is essentially the same as the company's business strategy. The social environment providing the market for communications services is undergoing rapid change in Japan as it evolves from an era of one basic mainstay service-namely, plain-old telephone service-to one in which a wide range of advanced new services are, or soon will be, available and there is fierce competition to provide those services. This paper covers some of the thinking behind NTT's strategy to put in place a flexible and effectual network that fully reflects the needs and desires of customers in this fast-changing environment.

  • Timing Driven Placement Based on Fuzzy Theory

    Ze Cang GU  Shoichiro YAMADA  Shojiro YONEDA  

     
    LETTER

      Vol:
    E75-A No:7
      Page(s):
    917-919

    A new timing driven placement method based on the fuzzy theory is proposed. In this method, the longest path delay, the chip area and the wire length can be simultaneously minimized. Introducing the probability measures of fuzzy events, falling down into the optimal solutions can be avoided.

  • Intelligent Network Service Operation Architecture

    Hiroshi TOKUNAGA  Yukuo KIRIHARA  

     
    PAPER

      Vol:
    E75-B No:7
      Page(s):
    617-623

    The establishment of an intelligent network service operation architecture is important for facilitating development and integration of service operation systems. To do this, the basic concepts and goals of service operation items must first be clarified. Then, the necessary procedures as well as the required data on the behaviors of customers, operators and operation systems must be described. These various points are discussed based on an operation study methodology.

  • Planning Global Intelligent Networks

    Stephen CHEN  Arik N. KASHPER  

     
    INVITED PAPER

      Vol:
    E75-B No:7
      Page(s):
    550-555

    The globalization of business where single products and services are designed, developed, and manufactured in many different countries signals a significant need for cost-effective and reliable information movement and management capabilities. Similarly, consumers are seeking technologies which will allow them to visit the Smithsonian, scan a book in the Oxford Library, and interview a Japanese monk for a school report, all from the comfort of home. A necessary ingredient for realizing this global society is a strong telecommunications infrastructure. Our paper describes some of the customer needs and technology advances that are causing a revolution in planning global telecommunications networks. We present a new telecommunications paradigm and study its impact in two key areas: multi-country network routing at both the traffic and facility levels, and global network robustness.

  • Plasmaless Dry Etching of Silicon Nitride Films with Chlorine Trifluoride Gas

    Yoji SAITO  Masahiro HIRABARU  Akira YOSHIDA  

     
    PAPER

      Vol:
    E75-C No:7
      Page(s):
    834-838

    Plasmaless etching using ClF3 gas has been investigated on nitride films with different composition. For the sputter deposited and thermally grown silicon nitride films containing no hydrogen, the etch rate increases and the activation energy decreases with increase of the composition ratio of silicon to nitrogen between 0.75 and 1.3. This fact indicates that the etching is likely to proceed through the reaction between Si and ClF3. The native oxide on the silicon-nitride films can also be removed with ClF3 gas. Ultra-violet light irradiation from a low pressure mercury lamp remarkably accelerates the removal of the native oxide and the etch rate of the thermally grown silicon-nitride films. For the plasma deposited films, the etch rate is strongly accelerate with increasing hydrogen content in the films, but the activation energy hardly depends on the bounded hydrogen in the films, consistent with the results for Si etching.

  • Reduced-Size Double Crosstie Slow-Wave Transmission Lines for MMICs

    Hideki KAMITSUNA  Hiroyo OGAWA  

     
    PAPER

      Vol:
    E75-C No:6
      Page(s):
    721-728

    This paper proposes three configurations of slow-wave transmission lines for MMICs, i.e., double crosstie slow-wave transmission line (DCT-SLW), meander-like DCT-SLW and lumped DCT-SLW. The DCT-SLW is based on periodic structures and triplate structures. The meander-like DCT-SLW realizes a drastic size reduction in the DCT-SLW using a meander configuration of inductive and capacitive transmission lines. The multilayer spiral inductors are introduced to obtain high impedance characteristics of the meander section. The lumped DCT-SLW achieves a large slow-wave factor of 30. These proposed structures are analytically and experimentally investigated, and excellent performance is obtained. It is also shown that the proposed DCT-SLWs are superior to thin film microstrip (TFMS) lines with the same insertion phase, as regards size.

  • A Layout System for Mixed A/D Standard Cell LSI's

    Ikuo HARADA  Hitoshi KITAZAWA  Takao KANEKO  

     
    PAPER

      Vol:
    E75-C No:3
      Page(s):
    322-332

    A layout system for mixed analog/digital standard cell LSI's is described. The system includes interactive floorplan and placement features and automatic global and channel router. In mixed analog/digital circuits, crosstalk noise causes chip performance degradation. Thus, the proposed global routing algorithm routes analog nets in areas that are free of digital nets as much as possible. The number of line crossovers, especially for analog nets, is minimized by both global and detailed routers, because these crossovers are the dominant factors in the crosstalk noise. Double width lines can be used to avoid unexpected voltage drops caused by parasitic resistances. A postprocess automatically puts up shield lines for very noise sensitive wirings to improve the S/N ratio. Experimental results show that the proposed algorithms are effective in reducing the number of crossovers and redundant vias.

  • Cell Designer: An Automatic Placement and Routing Tool for the Mixed Design of Macro and Standard Cells

    Young Seok BAEK  Byoung Yoon CHEON  Kyung Sik KIM  Hyun Chan LEE  Chul Dong LEE  

     
    PAPER-Computer Aided Design (CAD)

      Vol:
    E75-A No:2
      Page(s):
    224-232

    In this paper, we propose a new algorithm for the problem of floorplanning of the mixed design of macro and standard cells. The proposed algorithm which is based on partitioning and slicing approach, uses a modified min-cut bipartitioning heuristic. The heuristic bipartitions a block of a mixture of macro and standard cells to minimize the netcut, which are the number of nets connecting both sub-blocks, with size constraints. A sub-block is a resulting descendant block. Before starting the bipartitioning of the block, the macro cell with the longest side in the block is selected first. Using edges of the selected macro cell, bipartitionings are performed twice fixing the location of the macro cell on one of 4 corners of the block with its rotation and reflection. Bipartitioning of blocks is repeated until each block has either a macro cell or standard cells without macro cells. As a result of bipartitioning, a slicing tree is constructed. Using the proposed floorplan algorithm, we developed an automatic placement and routing tool, Cell Designer, for the mixed design of macro and standard cells. According to the floorplanner, macro cells are placed and standard cells are grouped into standard cell blocks. Standard cells are placed and routed within estimated area of block using conventional tools. They form a fixed-shaped block like a macro cell. Interconnections between the two adjacent blocks are performed with a conventional channel router. The channels and the order of channel routing are determined following the hierarchy of the slicing tree. Cell Designer has a dedicated graphics editor to provide interactive services to users. Experimental results on well-known benchmark data are shown.

  • An Analysis of the Mechanism of Monochromatisation of Ne-A-H2 Filled Plasma Display Light

    Geavit MUSA  Cristian Petrica LUNGU  Alexandrina POPESCU  Alexandra BALTOG  

     
    PAPER-Electronic Displays

      Vol:
    E75-C No:2
      Page(s):
    241-245

    A yellow light emitting display using neon-hydrogen-argon mixture as filling gas is presented. Strong "monochromatisation" of the emitted light is reported for the first time on the wavelength λ585.3 nm. Experimental results on the dependence of the "monochromatisation effect" is given for various pressure values and filling gas composition. It is underlined the existence of a process of selective population of the upper level 3p[1/2]0 of the transition corressponding to the wavelength 585.3 nm. The obtained results are discussed in relation with the reported results on yellow light laser in which a discharge in neon-hydrogen mixture is used for laser radiation generation at λ585.3 nm. The proposed explanation of different authors on the upper level population through radiative or dissociative recombination of neon ions is discussed and a new hypothesis is advanced for the strong monochromatisation observed in neon-hydrogen or neon-hydrogen-argon filled displays. According to this hypothesis, in the feeding process of the upper level 3p[1/2]0 are taking part the neon metastable states too. If such an assumption will come true, cyclic processes in yellow light generation might appear.

  • Evaluation of the Point Defect Bulk Recombination Rate by Ion Implantation at High Temperatures

    Peter PICHLER  Rainer SCHORK  Thomas KLAUSER  Heiner RYSSEL  

     
    PAPER

      Vol:
    E75-C No:2
      Page(s):
    128-137

    In recent years, ion implantation has become one of the key techniques in semiconductor fabrication. The annealing of the damage produced during implantation is, however, not fully understood. Ion implantation at high temperatures allows the time-resolved study of implantation-enhanced diffusion. During the process, point defects are generated by the ion implantation and consumed by recombination in the bulk as well as by diffusion to the surface and recombination there. With increasing temperatures, the recombination of point defects, which are acting as diffusion vehicles, results in reduced effective diffusion. Profiles processed above 900 show marked uphill diffusion at the surface caused by large gradients of the point defect concentrations. This uphill diffusion affirms the generally accepted pair diffusion theories. Since the point defects are in steady state even after process times which are short compared to the total process time, we are able to give a qualitative analysis of the dose dependence of the diffusion. By extensive numerical simulations, we could estimate the product of bulk recombination rate and equilibrium concentrations of self-interstitials and vacancies as well as the interface recombination velocity for the self-interstitials. The results obtained are in qualitative agreement with previous work of others. The results demonstrate, in fact, clearly the advantages of the method presented. But due to experimental problems concerning the temperature measurement, which have not been fully resolved up to now, the results have to be considered as crude estimates.

  • Effects of Line Resistance and Parasitic Capacitance on Transmittance Distribution in TFT-LCDs

    Kikuo ONO  Takeshi TANAKA  Jun OHIDA  Junichi OHWADA  Nobutake KONISHI  

     
    PAPER-Electronic Displays

      Vol:
    E75-C No:1
      Page(s):
    93-100

    Transmittance distribution along a horizontal line in LCDs addressed by amorphous silicon TFTs was investigated using measurements and calculations. Nonuniformity of the distribution, in which the transmittance increased with increasing distance from the left edge of the LCD, was observed in a 10 inch diagonal TFT-LCD. The cause of the nonuniformity was attributed to the decrease in voltage drop due to the gate source parasitic capacitance and the increase in gate voltage fall time due to large line resistance, based on the measurements of voltage drops in TFT test elements and calculations considering the decrease in voltage drop. The distribution could be improved by reducing the line resistance and parasitic capacitance in the actual LCD.

  • On Depth-Bounded Planar Circuits

    Masao IKEKAWA  

     
    PAPER

      Vol:
    E75-D No:1
      Page(s):
    110-115

    We study the depth of planar Boolean circuits. We show that planar Boolean circuits of depth D(n) are simulated by on-line Turing machines in space O(D(n)). From this relationship, it is shown that any planar circuit for computing integer multiplication requires linear depth. It is also shown that a planar analogue to the NC-hierarchy is properly separated.

  • Transient Electromagnetic Fields on a Conducting Sphere Excited by a Pulsed Plane Wave

    Akira ITOH  Toshio HOSONO  Yuuiti HIRAO  

     
    PAPER-Electromagnetic Theory

      Vol:
    E75-C No:1
      Page(s):
    107-112

    We studied transient fields on a perfectly conducting sphere excited by a half sine pulse wave and examined the Poynting vectors, the energy densities and the energy velocities of the creeping waves. We used FILT (Fast Inversion of Laplace Transform) method for transient analysis. We compared the amplitudes of the creeping wave with that of steady state high frequency approximation obtained by the Watson transformation. The main results are: (1) We confirmed in the transient response that the pulse propagates clockwise and counterclockwise along the geodesic circumference. (2) In the transient electromagnetic field observed in the E-plane we can recognize creeping waves clearly. (3) The existence of creeping waves is not clear in the H-plane. (4) The pulse wave propagation on the sphere is seen more clearly from the Poynting vectors and the energy densities than the field components. (5) The energy velocity of the wave front is equal to the light velocity as should be. The energy velocity of the wave body becomes smaller with the passage of time. (6) The amplitude of the creeping wave for a beat pulse and the amplitude obtained by the Watson transform for mono spectrum agree in the order of relative error below 25%.

1361-1376hit(1376hit)