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[Keyword] plane(179hit)

121-140hit(179hit)

  • A GMPLS Distributed Control Plane for Heterogeneous All-Optical Networks

    Yoshiharu MAENO  Itaru NISHIOKA  Yoshihiko SUEMURA  Soichiro ARAKI  

     
    PAPER

      Vol:
    E86-B No:8
      Page(s):
    2319-2326

    We evaluate resolution models for resource allocation in a GMPLS distributed control plane for heterogeneous all-optical networks. In a practical regional-to-backbone network environment, the local resolution model is advantageous in resource utilization, protocol compatibility and scalability. We demonstrate a lookup procedure, which inter-works with OSPF-TE and RSVP-TE protocols and allocates resources in the local resolution model.

  • Listing All Connected Plane Triangulations

    Zhang-Jian LI  Shin-ichi NAKANO  

     
    PAPER-Algorithms and Data Structures

      Vol:
    E86-A No:7
      Page(s):
    1807-1812

    A "rooted" plane triangulation is a plane triangulation with one designated vertex r and one designated edge incident to r on the outer face. In this paper we give a simple algorithm to generate all connected rooted plane triangulations with at most m edges. The algorithm uses O(m) space and generates such triangulations in O(1) time per triangulation without duplications. The algorithm does not output entire triangulations but the difference from the previous triangulation. By modifying the algorithm we can generate all connected (non-rooted) plane triangulations with at most m edges in O(m3) time per triangulation.

  • Performance Analysis of a DS-CDMA Cellular System with Cell Splitting into Macrocell and Microcell Architecture

    Jie ZHOU  Shigenobu SASAKI  Shogo MURAMATSU  Hisakazu KIKUCHI  Yoshikuni ONOZATO  

     
    PAPER-Terrestrial Radio Communications

      Vol:
    E86-B No:6
      Page(s):
    1967-1977

    The demand for wireless mobile communications has grown at a very high rate, recently. In order to solve the non-uniform traffic rates, the use of cell splits is unavoidable for balancing the traffic rate and maximizing total system capacity. For cell planning, a DS-CDMA cellular system can be comprise of different cell sizes because of different demands and population density of the service area. In this paper, we develop a general model to study the forward link capacity and outage probability of a DS-CDMA cellular system with mixed cell sizes. The analysis of outage probability is carried out using the log-normal approximation. When a macrocell is split into the three microcells, as an example, we calculate the multi-cross interferences between macrocells and microcells, and the forward link capacities for the microcells and the neighboring macrocells. The maximum allowable capacity plane for macrocell and microcell is also investigated. The numerical results and discussions with previous published results of reverse link are summarized.

  • Generating Biconnected Plane Quadrangulations

    Zhang-Jian LI  Shin-ichi NAKANO  

     
    PAPER-Algorithms

      Vol:
    E86-D No:4
      Page(s):
    698-703

    A plane quadrangulation is a plane graph such that each inner face has exactly four edges on its contour. This is a planar dual of a plane graph such that all inner vertices have degree exactly four. A based plane quadrangulation is a plane quadrangulation with one designated edge on the outer face. In this paper we give a simple algorithm to generate all biconnected based plane quadrangulations with at most f faces. The algorithm uses O(f) space and generates such quadrangulations in O(1) time per quadrangulation without duplications. By modifying the algorithm we can generate all biconnected (non-based) plane quadrangulations with at most f faces in O(f3) time per quadrangulation.

  • Efficient Generation of Plane Triangulations with a Degree Constraint

    Hiroyuki TANAKA  Zhangjian LI  Shin-ichi NAKANO  

     
    PAPER

      Vol:
    E86-A No:4
      Page(s):
    829-834

    A "based" plane triangulation is a plane triangulation with one designated edge on the outer face. In this paper we give a simple algorithm to generate all biconnected based plane triangulations with at most n vertices and with maximum degree at most D. The algorithm uses O(n) space and generates such triangulations in O(1) time per triangulation without duplications. The algorithm does not output entire triangulation but the difference from the previous triangulation. By modifying the algorithm we can generate all biconnected based plane triangulations with exactly n vertices and maximum degree at most D in O(1) time per triangulation, and all biconnected (non-based) plane triangulations with exactly n vertices and maximum degree at most D in O(n3) time per triangulation without duplications.

  • Application of the Alternating-Direction Implicit FDTD Method for Analyzing the Power Plane Resonance Problem

    Jeongnam CHEON  Hyunsik PARK  Hyeongdong KIM  

     
    LETTER-Antenna and Propagation

      Vol:
    E86-B No:3
      Page(s):
    1181-1185

    In this paper, the power plane resonance problem in a multi-layered PCB is numerically analyzed by applying the alternating-direction implicit (ADI) FDTD method. This method is extremely suitable for analyzing the power plane resonance problems having locally fine structures of two closely located planes. This paper also analyzes the effect of the decoupling capacitor, which is one of the solutions for reducing the resonance problem. The results of the ADI-FDTD agree well with those of the conventional FDTD and the analytic solutions, and the computational CPU time is reduced to about a half of that of the conventional FDTD.

  • A GA-Based Learning Algorithm for Binary Neural Networks

    Masanori SHIMADA  Toshimichi SAITO  

     
    LETTER-Nonlinear Problems

      Vol:
    E85-A No:11
      Page(s):
    2544-2546

    This paper presents a flexible learning algorithm for the binary neural network that can realize a desired Boolean function. The algorithm determines hidden layer parameters using a genetic algorithm. It can reduce the number of hidden neurons and can suppress parameters dispersion. These advantages are verified by basic numerical experiments.

  • Polyhedral Description of Panoramic Range Data by Stable Plane Extraction

    Caihua WANG  Hideki TANAHASHI  Hidekazu HIRAYU  Yoshinori NIWA  Kazuhiko YAMAMOTO  

     
    PAPER-Image Processing, Image Pattern Recognition

      Vol:
    E85-D No:9
      Page(s):
    1399-1408

    In this paper, we describe a novel technique to extract a polyhedral description from panoramic range data of a scene taken by a panoramic laser range finder. First, we introduce a reasonable noise model of the range data acquired with a laser radar range finder, and derive a simple and efficient approximate solution of the optimal fitting of a local plane in the range data under the assumed noise model. Then, we compute the local surface normals using the proposed method and extract stable planar regions from the range data by using both the distribution information of local surface normals and their spatial information in the range image. Finally, we describe a method which builds a polyhedral description of the scene using the extracted stable planar regions of the panoramic range data with 360 field of view in a polar coordinate system. Experimental results on complex real range data show the effectiveness of the proposed method.

  • Perturbational Analysis of Microstrip Antennas with Meshed Ground Planes

    Toru TAKAHASHI  Isamu CHIBA  

     
    PAPER-Antenna and Propagation

      Vol:
    E85-B No:9
      Page(s):
    1787-1796

    Microstrip antennas with meshed ground planes are suitable for radiation elements of large satellite phased array antennas. Although they have some mechanical advantages such as the possibility of antenna weight reduction, they also cause electrical problems such as the resonant frequency shift and F/B ratio degradation. The first purpose of this paper is the analytical understanding of the resonant frequency shift, for which two perturbational methods are proposed. One has a closed form expression that provides some useful design data. The other is to solve the integral equations by using the periodicity of the meshed ground plane, which gives more accurate results. The second purpose of this paper is to investigate the backward radiation from the meshed ground plane analytically, for which we derive an analysis method from the calculated results of the resonant frequency shift. The proposed methods are verified with the measured ones.

  • Enumerating Floorplans with n Rooms

    Shin-ichi NAKANO  

     
    LETTER-VLSI Design Technology and CAD

      Vol:
    E85-A No:7
      Page(s):
    1746-1750

    A plane drawing of a graph is called a floorplan if every face (including the outer face) is a rectangle. A based floorplan is a floorplan with a designated base line segment on the outer face. In this paper we give a simple algorithm to generate all based floorplans with at most n faces. The algorithm uses O(n) space and generates such floorplans in O(1) time per floorplan without duplications. The algorithm does not output entire floorplans but the difference from the previous floorplan. By modifying the algorithm we can generate without duplications all based floorplans having exactly n faces in O(1) time per floorplan. Also we can generate without duplications all (non-based) floorplans having exactly n faces in O(n) time per floorplan.

  • A New Decoupling Circuit for Suppressing Radiated Emissions due to Power Plane Resonance

    Hideki SASAKI  Takashi HARADA  Toshihide KURIYAMA  

     
    PAPER-Electromagnetic Compatibility(EMC)

      Vol:
    E85-B No:5
      Page(s):
    1031-1037

    This paper presents a new decoupling circuit for suppressing radiated emissions due to power plane resonance in multilayer printed circuit boards (PCBs). This circuit is based on transmission line theory, and consists of two decoupling capacitors and one power trace. The two capacitors, one mounted on the power pin of an IC and the other mounted on the common power distribution bus in a board, are connected through the power trace. The characteristic impedance of the trace is much higher than the impedance of the capacitors. In addition, the length of the trace between the capacitors is less than 1/4 the effective wavelength for high frequency (e.g., 1 GHz). Tests we performed on simple PCBs confirm that our decoupling circuit suppresses radiated emissions due to power plane resonance.

  • Fabrication and Properties of Planar Intrinsic Josephson Junctions with In-Plane Aligned YBCO Films

    Lan ZHANG  Masataka MORIYA  Takayuki KOBAYASHI  Masashi MUKAIDA  Toshinari GOTO  

     
    PAPER-Junctions and Processing

      Vol:
    E85-C No:3
      Page(s):
    764-768

    High-Tc superconductors convincingly showed that these materials are essentially natural arrays of Josephson junctions formed in atomic scale. In this paper, in-plane aligned a-axis-oriented YBa2Cu3O7-δ (YBCO) thin films were successfully grown on LaSrGaO4(LSGO) (100) substrates which were cleaned by ion-beam. Voltage jumps with hysteresis implying intrinsic Josephson effects are observed in c-axis direction. This result suggest that it is possible to achieve planar intrinsic Josephson devices which have applications in high frequency electronics, such as voltage standards, Josephson masers and so on.

  • HTS Surface-Modified Junctions with Integrated Ground-Planes for SFQ Circuits

    Yoshihisa SOUTOME  Tokuumi FUKAZAWA  Kazuo SAITOH  Akira TSUKAMOTO  Kazumasa TAKAGI  

     
    INVITED PAPER-Junctions and Processing

      Vol:
    E85-C No:3
      Page(s):
    759-763

    We fabricated ramp-edge junctions with barriers by modifying surface and integrating ground-planes. The fabricated junctions had current-voltage characteristics consistent with the resistive shunted-junction model. We also obtained a 1-sigma spread in the critical current of 7.9% for 100 junctions at 4.2 K. The ground-plane reduced the sheet inductance of a stripline by a factor of 3. The quality of the ground-plane was improved by using an anneal in oxygen atmosphere after fabrication. The sheet inductance of a counter-electrode with a ground-plane was 1.0 pH per square at 4.2 K.

  • A Probabilistic Approach to Plane Extraction and Polyhedral Approximation of Range Data

    Caihua WANG  Hideki TANAHASHI  Hidekazu HIRAYU  Yoshinori NIWA  Kazuhiko YAMAMOTO  

     
    PAPER-Image Processing, Image Pattern Recognition

      Vol:
    E85-D No:2
      Page(s):
    402-410

    In this paper, we propose a probabilistic approach to derive an approximate polyhedral description from range data. We first compare several least-squares-based methods for estimation of local normal vectors and select the most robust one based on a reasonable noise model of the range data. Second, we extract the stable planar regions from the range data by examining the distributions of the local normal vectors together with their spatial information in the 2D range image. Instead of segmenting the range data completely, we use only the geometries of the extracted stable planar regions to derive a polyhedral description of the range data. The curved surfaces in the range data are approximated by their extracted plane patches. With a probabilistic approach, the proposed method can be expected to be robust against the noise. Experimental results on real range data from different sources show the effectiveness of the proposed method.

  • Iterative Round-Robin Matching for Input and Output Buffered Switches

    Man-Soo HAN  

     
    LETTER-Switching

      Vol:
    E84-B No:12
      Page(s):
    3290-3294

    We present iterative round-robin matching for an input and output buffered switch with multiple switching planes. The suggested algorithm is based on iSLIP and consists of request, grant and accept steps. The pointer update scheme of iSLIP is altered in the suggested algorithm to enhance the switch performance. Simulation results under Bernoulli traffic show the suggested algorithm is more appropriate than iSLIP for cell scheduling of input and output buffered switches.

  • APIs for Flow Control and Their Applications

    Arata KOIKE  

     
    PAPER-Mobile Service and Technologies

      Vol:
    E84-B No:12
      Page(s):
    3173-3180

    Reliable and scalable network technologies are desired to meet the emerging demand for multimedia communication. Asynchronous Transfer Mode (ATM) is a key technology and its importance is widely recognized. An ATM layer service category, Available Bit Rate (ABR), was specified at the ATM Forum in 1996. ABR is intended to meet the requirements of non-real-time applications that assume best effort data transportation. It has distinctive features compared to other ATM layer categories. We proposed Application Program Interfaces (APIs) for ABR that allow applications to use ABR capability directly. The API is now a part of the ATM Forum specification. In this paper, we describe the background and necessity of ABR APIs and explain the primitives for them in detail. In addition to having common API primitives for requesting bandwidth or delay requirements during connection setup, ABR APIs can exchange feedback information during communication. Applications for such APIs are addressed and their effectiveness is shown by demonstrating simulation for the TCP-ABR interworking for a backbone ABR network. Finally, a migration scenario for utilizing such APIs is proposed.

  • An Excellent Cost-Performance Antenna Duplexer for 26 GHz FWA Systems

    Toshio ISHIZAKI  Toshihiro TERAOKA  Koichi OGAWA  

     
    PAPER

      Vol:
    E84-C No:10
      Page(s):
    1515-1520

    Cost down of millimeter wave components, especially antenna duplexer, is a key for spreading millimeter wave communication systems. An excellent cost-performance antenna duplexer is proposed. It consists of two E-plane filters and a wave-guide circulator. The performance fluctuations due to manufacturing accuracies are studied by simulations and experiments. These results are very useful for cost-down of the practical duplexer without performance degradation.

  • A Millimeter-Wave Radial Line Slot Antenna Fed by a Rectangular Waveguide through a Ring Slot

    Kaoru SUDO  Akira AKIYAMA  Jiro HIROKAWA  Makoto ANDO  

     
    PAPER

      Vol:
    E84-C No:10
      Page(s):
    1521-1527

    Rectangular/circular-to-radial waveguide tra-nsformers through a ring slot have been proposed for the feeder of radial line slot antennas (RLSAs) in millimeter wave application. Rotating electric modes are excited by a set of ring slot and perturbation dog bone slot. Basic operation is observed in 12 GHz band. Concentric array radial line slot antennas fed by these transformers are fabricated and the antenna gain of 26.9 dBi with the efficiency more than 60% is measured. The applicability for millimeter wave is verified for 38 GHz band RLSA fed by the rectangular waveguide. The measured gain of the antenna is 22.5 dBi with the efficiency of 53% with the diameter of 46mm and 26.4 dBi with 61% with the diameter of 66mm.

  • Effects of a Parasitic Wire on Coupling between Two Slot Antennas

    Takehiro MORIOKA  Koji KOMIYAMA  Kazuhiro HIRASAWA  

     
    PAPER-EMC

      Vol:
    E84-B No:9
      Page(s):
    2597-2603

    Coupling between two slot antennas on an infinite ground plane and radiation patterns on a finite ground plane are calculated. We introduce a parasitic wire between slot antennas to reduce coupling. Two typical cases with a monopole or a half-loop are considered in this paper. Numerical results show that the reduction of 13.9 dB is obtained by adjusting a monopole height to about a quarter wavelength of the operating frequency. Also a properly adjusted parasitic half-loop reduces the coupling coefficient by 24 dB. Radiation patterns of the antennas on a 365 mm 465 mm ground plane at 1.5 GHz are calculated where the diffracted fields are taken into account. It is found that the parasitic elements little affect the antenna patterns around the +z-axis that is perpendicular to the ground plane although the reduction of coupling between slot antennas is obtained.

  • Fast Algorithms for k-Word Proximity Search

    Kunihiko SADAKANE  Hiroshi IMAI  

     
    PAPER-Algorithms and Data Structures

      Vol:
    E84-A No:9
      Page(s):
    2311-2318

    When we search from a huge amount of documents, we often specify several keywords and use conjunctive queries to narrow the result of the search. Though the searched documents contain all keywords, positions of the keywords are usually not considered. As a result, the search result contains some meaningless documents. It is therefore effective to rank documents according to proximity of keywords in the documents. This ranking is regarded as a kind of text data mining. In this paper, we propose two algorithms for finding documents in which all given keywords appear in neighboring places. One is based on plane-sweep algorithm and the other is based on divide-and-conquer approach. Both algorithms run in O(n log n) time where n is the number of occurrences of given keywords. We run the algorithms on a large collection of html files and verify its effectiveness.

121-140hit(179hit)