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[Keyword] patch(82hit)

61-80hit(82hit)

  • Novel Periodic Structures for a Slotline : Patch Loaded Slotline

    Jongkuk PARK  Jong-Sik LIM  Sangwook NAM  

     
    LETTER-Microwaves, Millimeter-Waves

      Vol:
    E88-C No:1
      Page(s):
    135-138

    In this Letter, a dumbbell-shaped patch loaded slotline(PLS) is proposed. Like the conventional defected ground structure(DGS) for a microstrip line, we show that the proposed PLS can provide a wide bandstop characteristic in some frequency bands with only one or small number of unit cells. Also, the equivalent circuit model for a unit section is derived from the analysis of the field distributions in the structure and its circuit parameters are determined by means of full wave numerical simulations. This equivalent circuit is shown to be dual to that of the typical DGS in a microstrip line. A broadband microstrip to slotline transition is incorporated in the PLS in order to measure the characteristics of the structure. The experimental results agree well with the simulations and show the validity of the modeling for the proposed PLS.

  • Compact Wideband Patch Antenna with Bent Y-Probe Feeding

    Qi DONG-SHENG  Li BIN-HONG  

     
    LETTER-Electromagnetic Theory

      Vol:
    E88-C No:1
      Page(s):
    133-134

    A compact wideband patch antenna with bent Y-probe is proposed and studied. With the bent Y-probe and substrate thickness of about 0.14λ0, a bandwidth (VSWR below 2) of 54.6% has been achieved. The size of the antenna is decreased due to the shorting wall and Y-probe. The radiation patterns and the gains across the band are also studied.

  • Secure Detection of Watermarks

    Jun FURUKAWA  

     
    PAPER-Applications

      Vol:
    E87-A No:1
      Page(s):
    212-220

    There are two main types of digital watermark systems. In the first, users are given their own detection programs by which to verify the presence of watermark in data they have in their possession. In the second, users must request such verification from a detection center. The disadvantage of the first type is the possibility that a user might be able to analyze the detection program sufficiently to be able to obtain the secret data (secret key) used to embed the watermark. The disadvantage of the second is the possibility that a center might give dishonest results. In this paper, we propose a watermark detection scheme that can be used to overcome the disadvantages of both: it prevents users from obtaining secret key, and it prevents a center from reporting dishonest results. Our scheme is based on a previously proposed scheme which nearly achieved the same goals but, unfortunately, allowed users to receive watermark detection results for data specially created by them so as to reveal, through the results, secret information about how a center created its watermarks. To overcome this drawback, we have developed new scheme by which a center can prove its detection results to a user without revealing any other information. This scheme was developed by extending the work found in. Moreover we provide an option that prevents the center from encroaching on a user's privacy. The resulting watermark detection scheme is the first that, in addition to protecting secret keys of watermarks from user-tampering, is also able to prevent a center from reporting dishonest results. Although the proposed scheme is introduced first using the patch-work watermarking system, it is straightforward to extend it to a scheme that uses the correlation-based watermarking system, which yields a more robust watermark detection scheme.

  • Polarization Switchable Microstrip Antenna Using PIN Diodes

    Dongkeun JUNG  Takeshi FUKUSAKO  Naoki KITAMURA  Nagahisa MITA  Cheunsoo HA  

     
    PAPER-Antennas and Propagation

      Vol:
    E87-B No:1
      Page(s):
    152-157

    A polarization switchable slot-coupled microstrip antenna using PIN diodes is proposed and studied. The microstrip feed line installed behind the ground plane is divided into two branches and each tip of the branches is connected to the ground plane through a PIN diode. One of the diodes is oriented from the tip to the ground plane and the other is oriented from the ground to the tip so that a slot in the ground can be selected to feed the patch by switching the dc bias between positive and negative. This selection contributes to switch the polarization between horizontal and vertical. In this paper, the authors investigate the polarization switching antenna theoretically and experimentally and confirmed sufficient differencce of antenna gain between horizontal and vertical polarization.

  • A Method for Watermarking to Bezier Polynomial Surface Models

    Hiroshi NAGAHASHI  Rikima MITSUHASHI  Ken'ichi MOROOKA  

     
    PAPER-Computer Graphics

      Vol:
    E87-D No:1
      Page(s):
    224-232

    This paper presents a new method for embedding digital watermarks into Bezier polynomial patches. An object surface is supposed to be represented by multiple piecewise Bezier polynomial patches. A Bezier patch passes through its four-corner control points, which are called data points, and does not pass through the other control points. To embed a watermark, a Bezier patch is divided into two patches. Since each subdivided patch shares two data points of the original patch, the subdivision apparently generates two additional data points on the boundaries of the original patch. We can generate the new data points in any position on the boundaries by changing the subdivision parameters. The additional data points can not be removed without knowing some parameters for subdividing and deforming the patch, hence the patch subdivision enables us to embed a watermark into the surface.

  • Video Watermarking of Which Embedded Information Depends on the Distance between Two Signal Positions

    Minoru KURIBAYASHI  Hatsukazu TANAKA  

     
    PAPER-Image

      Vol:
    E86-A No:12
      Page(s):
    3267-3275

    One of the important topics of watermarking technique is a robustness against geometrical transformations. In the previous schemes, a template matching is performed or an additional signal is embedded for the recovery of a synchronization loss. However, the former requires the original template, and the latter degrades the quality of image because both a watermark and a synchronization signal must be embedded. In the proposed scheme only a synchronization signal is embedded for the recovery of both a watermark and a synchronization loss. Then the embedded information depends on the distance between two embedded signal positions. The distance is not changed seriously by random geometrical transformations like StirMark attack unless the embedded signal is disturbed. Therefore, a watermark can be extracted correctly from such geometrically transformed image if the synchronization signal can be recovered.

  • Design of LTCC Filters Using a Cross Patch

    Jun HAYASHI  Yoshio NIKAWA  

     
    PAPER-Passive(Filter)

      Vol:
    E86-C No:12
      Page(s):
    2412-2416

    A conventional waveguide filter is usually composed of a waveguide which is set with irises and posts inside. When dielectric material is not loaded inside the filter, the filter is too large to mount it on a planar circuit even if the frequency band is as high as the millimeter-wave band. In this paper, we propose a dielectric waveguide filter using LTCC (Low-Temperature Co-fired Ceramics) which can be mounted on a planar circuit. The dielectric waveguide filter using LTCC is composed of a dielectric-loaded waveguide including posts (via holes) and TEM-TE10 converters. The design method of the filter is shown and comparison of the simulated and the experimental results in the 6 GHz band is demonstrated. The simulated results agreed well with the experimental ones. To improve the attenuation characteristics, particularly at the above pass-band frequencies, an attenuation pole is added using a cross patch set inside the LTCC filter in the 25 GHz band. The effect of the cross patch is confirmed using the same simulation method as used for the 6 GHz band. As a result, it is confirmed that the cross patch is very useful for improving the attenuation characteristics at the above pass-band frequencies.

  • High-Temperature Superconductive Photomixer Patch Antenna: Theory and Design

    Daryoosh SAEEDKIA  A. Hamed MAJEDI  S. SAFAVI-NAEINI  Raafat R. MANSOUR  

     
    PAPER-MWP Devices

      Vol:
    E86-C No:7
      Page(s):
    1318-1327

    This paper presents a novel mm-wave and THz device concept, with a detailed physical modeling and quantitative performance evaluation, called as CW HTS (high temperature superconductive) photomixer/antenna. Optical heterodyne photomixing in the DC-biased HTS strip has been employed to create mm-wave and THz signal, and the size of strip on the grounded dielectric substrate is designed to have an efficient broadside radiation. Incorporating the HTS microstrip configuration as both photomixing media and radiation element at the same time not only increases the CW photocurrent but also the radiation power, while it reduces the radiation loss associated with the patch antenna. Two possible configurations called as longitudinal and transversal will be introduced and their photomixing efficiency and output radiation power will be compared. The detailed analysis along with the optimum design of the geometrical parameters of the microstrip structure shows that the transversal scheme exhibits higher radiation power. The typical nW output power can be obtained by mW laser pump power for frequencies up to the gap frequency of the HTS material. The output power of the proposed device is theoretically higher than the experimentally available data from a Low-Temperature-Grown (LTG) GaAs photomixer integrated with dipole or bow-tie antenna reported in the literature.

  • Wideband Notched Patch Antenna with a Pair of L-Strip Feeder

    Joo Seong JEON  Jong Kyu KIM  

     
    LETTER-Antenna and Propagation

      Vol:
    E86-B No:7
      Page(s):
    2237-2241

    In an attempt to enhance the impedance bandwidth and gain, a notched patch antenna is proposed that has a pair of L-strip feeders, and it has been experimentally studied. The enhanced features were confirmed and proved by comparing the proposed antenna with the antennae that have been reported in the relevant literatures. The experimental results showed that the impedance bandwidth (SWR2) of 35.74% and the peak gain of 8.69 dBi (at 2.17 GHz) were obtained by the frequency band under 2.5 GHz. Designed originally for PCS and IMT-2000 service band, the proposed antenna, with its simple structure, may easily be mass-produced and may have various commercial applications.

  • Bidirectional Rod Antennas Comprising a Narrow Patch and Parasitic Elements

    Keizo CHO  Toshikazu HORI  Kenichi KAGOSHIMA  

     
    PAPER-Mobile Antennas

      Vol:
    E84-B No:9
      Page(s):
    2482-2489

    This paper proposes a novel bi-directional rod antenna comprising a narrow patch and parasitic elements for base station antennas of street microcell systems. It is shown that the parasitic elements improve the antenna efficiency of an ordinary bi-directional printed antenna and make it possible to form the antennas using conventional substrates. This paper also proposes a suitable configuration for the array and investigates radiation characteristics of the configuration. Finally, a prototype of the bi-directional rod antenna is presented and the effectiveness of the bi-directional antenna is evaluated.

  • Recovering the 3D B-Spline Control Points of the Free Curves for Shape Reforming

    Myint Myint SEIN  Hiromitsu HAMA  

     
    PAPER

      Vol:
    E84-D No:8
      Page(s):
    983-989

    This paper presents an accurate method for finding the 3D control points of the B-Spline curves. This method can automatically fit a set of data points with piecewise geometrically continuous cubic B-Spline curves. Iterating algorithm has been used for finding the 2D control points. And a new approach for shape reconstruction based on the control points of the curves on the object's surface is proposed. B-Spline patch, the extension of the B-Spline curves to surface, provides recovering the shape of the object in 2D approach. The 3D control points of the cubic B-Spline curves are computed from the factor decomposition of the measurement matrix of 2D control points. The multiple object approach is also proposed to reconstruct the 3D shape of each curves of an object. Some experiments are demonstrated to confirm the effectiveness of our proposed method.

  • Optically-Fed Radio Access Point Module for a Fibre-Radio Downlink System

    Seiji FUKUSHIMA  Hideki FUKANO  Kaoru YOSHINO  Yutaka MATSUOKA  Seiko MITACHI  Kiyoto TAKAHATA  

     
    LETTER-Microwaves, Millimeter-Waves

      Vol:
    E84-C No:2
      Page(s):
    271-273

    A compact optically-fed radio access point module was developed that consists of a uni-traveling-carrier refracting-facet photodiode, a patch antenna, and an optical input interface. An output power from the photodiode was 1.4 dBm at a frequency of 5.88 GHz without any bias voltage.

  • An Image Correction Scheme for Video Watermarking Extraction

    Akihiko KUSANAGI  Hideki IMAI  

     
    PAPER

      Vol:
    E84-A No:1
      Page(s):
    273-280

    Watermarking techniques proposed up to now have some measure of robustness against non-geometrical alteration, however, most of them are not so robust against geometrical alteration. As also for video watermarking, small translation, scaling, rotation, affine transformation can be effective attacks on the watermark. In this paper, we propose an image correction scheme for video watermarking extraction. This scheme embeds 'patchwork' into digital video data for detection of positions, and corrects the images attacked by geometrical alteration on the basis of the detected positions. We also show the simulation results of applying proposed scheme to the conventional watermarking technique.

  • Planar PBG Structures: Basic Properties and Applications

    Fei-Ran YANG  Roberto COCCIOLI  Yongxi QIAN  Tatsuo ITOH  

     
    INVITED PAPER

      Vol:
    E83-C No:5
      Page(s):
    687-696

    This paper reviews recent progresses in the research and development of planar photonic band-gap (PBG) structures, also called electromagnetic crystals, for microwave and millimeter-wave applications. Planar electromagnetic crystals are particularly attractive and intensively investigated because of their easy fabrication, low cost, and compatibility with standard planar circuit technology. Two configurations and their applications are described in this paper: a square lattice of holes etched in a ground plane and the recently developed Uniplanar Compact PBG (UC-PBG) structure. Basic properties as well as applications to microwave circuits are reported. These include harmonic tuning in power amplifier, leakage suppression in conductor-backed coplanar waveguide (CB-CPW), realization of planar slow-wave structure, and performance improvement in microstrip filters and patch antennas.

  • Effect of 300 mm Wafer Transition and Test Processing Logistics on VLSI Manufacturing Final Test Process Efficiency and Cost

    Akihisa CHIKAMURA  Koji NAKAMAE  Hiromu FUJIOKA  

     
    PAPER-Integrated Electronics

      Vol:
    E82-C No:4
      Page(s):
    638-645

    The effect of lot size change and test processing logistics on VLSI manufacturing final test process efficiency and cost due to the transition of from conventional 5 or 6 inches to 300 mm (12 inches) in wafer size is evaluated through simulation analysis. Simulated results show that a high test efficiency and a low test cost are maintained regardless of arrival lot size in the range of the number of 300 mm wafers per lot from 1 to 25 and the content of express lots in the range of up to 50% by using WEIGHT+RPM rule and the right final test processing logistics. WEIGHT+RPM rule is the rule that considers the jig and temperature exchanging time, the lot waiting time in queue and also the remaining processing time of the machine in use. The logistics has a small processing and moving lot size equal to the batch size of testing equipment.

  • Effect of Express Lots on Production Dispatching Rule Scheduling and Cost in VLSI Manufacturing Final Test Process

    Akihisa CHIKAMURA  Koji NAKAMAE  Hiromu FUJIOKA  

     
    PAPER-Integrated Electronics

      Vol:
    E82-C No:1
      Page(s):
    86-93

    we evaluate the effect of express lots on production dispatching rule scheduling and cost in VLSI manufacturing final test process. In the assignment of express lots, we make comparisons of two rules, First In First Out (FIFO) rule which is widely used and WEIGHT+RPM rule which considers the time required for jig and temperature exchanges, the remaining processing time of the machine in use and the lot waiting time in queue. When using FIFO rule, the test efficiency begins to deteriorate and the test cost per chip begins to increase, if the content of express lots exceeds 15%. Furthermore, for 30% of express lots' content, the number of total processed lots decreases by 19% and the test cost per chip increases by 22% in comparison to the cases including no express lots. For WEIGHT+RPM rule, however, the test efficiency does not deteriorate and the test cost per chip does not increase even if the content of express lots is increased up to 50%. When we use WEIGHT+RPM rule, Express Lots Tolerances (ELTs), defined as the maximum content of express lots which permits the deterioration of the system characteristics by 5%, are about three times as high as ones when using FIFO rule. It is also found that WEIGHT+RPM rule maintains higher ELTs against the changes in the numbers of planned chips and prepared jigs as compared with FIFO rule.

  • Emergent Synchronization in Multi-Elevator System and Dispatching Control

    Takashi HIKIHARA  Shinichi UESHIMA  

     
    PAPER

      Vol:
    E80-A No:9
      Page(s):
    1548-1533

    In this paper, we discuss an emergent behavior of a multi-elevator system. The system includes multiple elevators in an office building and the Poisson arrival of passengers as its input. Elevators move up and down to serve calls and carry passengers according to given working rules. The system is a representative discrete event dynamic system, and is a nonlinear complex system. When people leave a building at the closing time, the down-peak traffic of passengers occurs. We show numerically that (1) this causes a jamming effect, which reduces the transportation efficiency, (2) there exists a threshold in the arrival rate of passengers, at which the traffic rate starts decreasing, and (3) this jamming effect is due to the synchronization of elevators. Then we propose a dispatching control that prevents elevators from synchronizing. This control is applied to each elevator as an anxiliary working rule. We can remove the jamming effect and recover the transportation efficiency by the control.

  • A Contour-Based Approach for Determining the Motion of 3-D Objects from a Sequence of Images

    Kazuho ITO  Kiyomi KANAZAWA  Yoshihiko SUZUKI  

     
    PAPER-Image Processing,Computer Graphics and Pattern Recognition

      Vol:
    E79-D No:9
      Page(s):
    1305-1316

    This paper addresses the problem of estimating 3-D motion of a rigid object from a sequence of monocular 2-D images. The surface of object is assumed to be modeled with several patches, each of which is expressed by an implicit equation. The proposed method estimates the pose (i.e., the location and orientation) of object that corresponds to each image in the sequence: The sequence of the estimated poses gives the motion of the object. The estimation is done by solving a system of equations, each of which is typically an algebraic equation of low degree, that is derived from the expressions of the surface patches and image contours data: so the method does not require establishing the correspondence between successive two frames in the image sequence or computing optic flow. Allowing several-patch models for objects enables the proposed approach to deal with a great variety of objects. The paper includes a numerical example, where our aproach has been applied to a polyhedral object modeled with several patches.

  • Scattering by Two-Dimensional Rectangular Resistive Plane Gratings with Anisotropic Slab

    Masamitsu ASAI  Jiro YAMAKITA  Shinnosuke SAWA  Junya ISHII  

     
    PAPER

      Vol:
    E78-C No:10
      Page(s):
    1453-1459

    We present a 44 matrix-based analysis of scattering form a two-dimensional rectangular resistive plane gratings placed on an anisotropic dielectric slab. The solution procedure used is formulated by extending the 44 matrix approach. The fields are expanded in terms of two-dimensional Floquet modes. Total fields can be given as sum of primary and secondary fields whose expression are obtained through eigenvalue problem of coupled wave matrix. Unknown currents on resistive patches are determined by applying Galerkin's method to the resistive boundary condition on resistive grating. Results are compared with other numerical examples available in the literature for isotropic cases. Further, numerical calculation are performed in the case of gratings with polar-type anisotropic slab.

  • A Job Dependent Dispatching Scheme in a Heterogeneous Multiserver Network

    Tsuyoshi OHTA  Takashi WATANABE  Tadanori MIZUNO  

     
    PAPER

      Vol:
    E77-B No:11
      Page(s):
    1380-1387

    In this paper, we propose the architecture of BALANCE (Better Adaptive Load-balancing through Acquiring kNowledge of Characteristic of an Environment) in which users can submit their jobs without acquiring either a status of an environment or characteristics of jobs and servers even in a widely connected heterogeneous network. The architecture of BALANCE includes three types of information bases and two types of daemons. Information bases, namely job, resource, and environment information base, manage the knowledge of job characteristics, available resources for CPUs, and status of the environment, respectively, as a proxy for users. The dispatching daemon selects an adequate server for each job using knowledge stored in the information bases. A service daemon executes each job. On completing each job, a service daemon gets a statistic of the job and returns it to the dispatching daemon where the job came from so that the statistic will be available at the next dispatching time. BALANCE enables an environment (1) to balance the load, (2) to share software functions as well as hardware facilities, and (3) to learn a user's job characteristics. We have implemented a prototype with more than 50 heterogeneous UNIX workstations connected by different networks. Two simple experiments on this prototype are presented. These experiments show a load balancing scheme that takes the characteristics of each job into account.

61-80hit(82hit)