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[Keyword] ATI(18690hit)

5341-5360hit(18690hit)

  • A Robust Method for Recognition of Complicated Pulse Repetition Interval Modulations

    Mahmoud KESHAVARZI  Amir Mansour PEZESHK  Forouhar FARZANEH  Delaram AMIRI  

     
    LETTER-Communication Theory and Signals

      Vol:
    E96-A No:11
      Page(s):
    2306-2310

    After receiving emitted signals from various radars by electronic support measures (ESM) system, several processes are applied to signals such as: deinterleaving, recognition of pulse repetition interval (PRI) modulation, PRI estimation and etc. Indeed, recognition of PRI modulation is an essential task of ESM system. In this paper a novel and robust method for recognition of complicated PRI Modulations is presented. This method uses specifications such as distribution related to members of sequences obtained from first and second order derivation of TOAs around a constant value and continuity of these sequences to recognize the PRI modulation. Some numerical simulations are performed to illustrate the effectiveness of proposed method. Simulation results show high robustness of proposed method against noise (spurious and missing pulses) and unwanted jitter.

  • Bi-level Relative Information Analysis for Multiple-Shot Person Re-Identification

    Wei LI  Yang WU  Masayuki MUKUNOKI  Michihiko MINOH  

     
    PAPER-Image Recognition, Computer Vision

      Vol:
    E96-D No:11
      Page(s):
    2450-2461

    Multiple-shot person re-identification, which is valuable for application in visual surveillance, tackles the problem of building the correspondence between images of the same person from different cameras. It is challenging because of the large within-class variations due to the changeable body appearance and environment and the small between-class differences arising from the possibly similar body shape and clothes style. A novel method named “Bi-level Relative Information Analysis” is proposed in this paper for the issue by treating it as a set-based ranking problem. It creatively designs a relative dissimilarity using set-level neighborhood information, called “Set-level Common-Near-Neighbor Modeling”, complementary to the sample-level relative feature “Third-Party Collaborative Representation” which has recently been proven to be quite effective for multiple-shot person re-identification. Experiments implemented on several public benchmark datasets show significant improvements over state-of-the-art methods.

  • T-YUN: Trustworthiness Verification and Audit on the Cloud Providers

    Chuanyi LIU  Jie LIN  Binxing FANG  

     
    PAPER-Computer System

      Vol:
    E96-D No:11
      Page(s):
    2344-2353

    Cloud computing is broadly recognized as as the prevalent trend in IT. However, in cloud computing mode, customers lose the direct control of their data and applications hosted by the cloud providers, which leads to the trustworthiness issue of the cloud providers, hindering the widespread use of cloud computing. This paper proposes a trustworthiness verification and audit mechanism on cloud providers called T-YUN. It introduces a trusted third party to cyclically attest the remote clouds, which are instrumented with the trusted chain covering the whole architecture stack. According to the main operations of the clouds, remote verification protocols are also proposed in T-YUN, with a dedicated key management scheme. This paper also implements a proof-of-concept emulator to validate the effectiveness and performance overhead of T-YUN. The experimental results show that T-YUN is effective and the extra overhead incurred by it is acceptable.

  • An Equivalent Double Layer Model for a Fast Design and Analysis of High Gain-Multilayer Radial Line Slot Antennas

    Tung NGUYEN  Rushanthi JAYAWARDENE  Yasutomo TAKANO  Kimio SAKURAI  Jiro HIROKAWA  Makoto ANDO  Osamu AMANO  Shuichi KOREEDA  Takaomi MATSUZAKI  Yukio KAMATA  

     
    PAPER-Antennas and Propagation

      Vol:
    E96-B No:11
      Page(s):
    2891-2900

    Light weight RLSAs with a honeycomb-type parallel plate are promising candidates for satellite antennas. However, the design of slot lengths and positions in honeycomb RLSAs consisting of a core, skin and adhesive layers involves time-consuming EM analysis. In this paper, an equivalent double layer model is devised for fast slot coupling analysis by the Method of moments (MoM) together with a simplified array design procedure. A fabricated antenna with a diameter of 900mm demonstrates the high directivity of 48.3dBi and a gain of 44.6dBi at 32GHz, with the reflection below -15dB. This antenna weighs only 1.16kg.

  • Analytic Ldi/dt Effect Model Based on Float Ground in Plasma Display Panel Driver System

    Xiaoying HE  Weifeng SUN  Guohuan HUA  Shen XU  Shengli LU  

     
    PAPER-Electronic Displays

      Vol:
    E96-C No:11
      Page(s):
    1428-1435

    An Ldi/dt effect model based on float ground in a plamsa display panel (PDP) driver system is established in this paper. The model is to analyze the noise which appears in power supply and float ground pins of driver integrated circuits. Considering printed circuit board wiring and switching parasitic parameters, firstly Ldi/dt effect due to integrated circuits transition, is explained on the entire float-ground circuit operation. Then an analytic model is deduced and validated, and good agreement is obtained with experimental results. Based on the model, sensitivity analyses of key parameters are done. Finally, design optimisations to prevent the Ldi/dt effect based on float ground are proposed and verified in a PDP system.

  • Fixed-Rate Resource Exchange for Multi-Operator Pico eNodeB

    Tomohiko MIMURA  Koji YAMAMOTO  Masahiro MORIKURA  Ayako IWATA  Takashi TAMURA  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E96-B No:11
      Page(s):
    2913-2922

    In this paper, we introduce a new multi-operator pico eNodeB (eNB) concept for cellular networks. It is expected that mobile data offloading will be performed effectively after installing the pico eNBs in cellular networks, owing to the rapid increase in mobile traffic. However, when several different operators independently install the pico eNBs, high costs and large amounts of space will be required for the installation. In addition, when several different operators accommodate their own user equipments (UEs) in the pico eNBs, not enough UEs can be accommodated. This is because the UEs are not evenly distributed in the coverage area of the pico eNBs. In this paper, the accommodation of the UEs of different operators in co-sited pico eNB is discussed as one of the solutions to these problems. For the accommodation of the UEs of different operators, wireless resources should be allocated to them. However, when each operator independently controls his wireless resources, the operator is not provided with an incentive to accommodate the UEs of the other operators in his pico eNBs. For this reason, an appropriate rule for appropriate allocation of the wireless resources to the UEs of different operators should be established. In this paper, by using the concepts of game theory and mechanism design, a resource allocation rule where each operator is provided with an incentive to allocate the wireless resources to the UEs of different operators is proposed. With the proposed rule, each operator is not required to disclose the control information like link quality and the number of UEs to the other operators. Furthermore, the results of a throughput performance evaluation confirm that the proposed scheme improves the total throughput as compared with individual resource allocation.

  • Virtual Halo Effect Using Graph-Cut Based Video Segmentation

    Sungchan OH  Hyug-Jae LEE  Gyeonghwan KIM  

     
    LETTER-Image Processing and Video Processing

      Vol:
    E96-D No:11
      Page(s):
    2492-2495

    This letter presents a method of adding a virtual halo effect to an object of interest in video sequences. A modified graph-cut segmentation algorithm extracts object layers. The halo is modeled by the accumulation of gradually changing Gaussians. With a synthesized blooming effect, the experimental results show that the proposed method conveys realistic halo effect.

  • Auto-Tuning of Thread Assignment for Matrix-Vector Multiplication on GPUs

    Jinwei WANG  Xirong MA  Yuanping ZHU  Jizhou SUN  

     
    PAPER-Fundamentals of Information Systems

      Vol:
    E96-D No:11
      Page(s):
    2319-2326

    Modern GPUs have evolved to become a more general processor capable of executing scientific and engineering computations. It provides a highly parallel computing environment due to its large number of computing cores, which are suitable for numerous data parallel arithmetic computations, particularly linear algebra operations. The matrix-vector multiplication is one of the most important dense linear algebraic operations. It is applied to a diverse set of applications in many fields and must therefore be fully optimized to achieve a high-performance. In this paper, we proposed a novel auto-tuning method for matrix-vector multiplication on GPUs, where the number of assigned threads that are used to compute one element of the result vector can be auto-tuned according to the size of matrix. On the Nvidia's GPU GTX 650 with the most recent Kepler architecture, we developed an auto-tuner that can automatically select the optimal number of assigned threads for calculation. Based on the auto-tuner's result, we developed a versatile generic matrix-vector multiplication kernel with the CUDA programming model. A series of experiments on different shapes and sizes of matrices were conducted for comparing the performance of our kernel with that of the kernels from CUBLAS 5.0, MAGMA 1.3 and a warp method. The experiments results show that the performance of our matrix-vector multiplication kernel is close to the optimal behavior with increasing of the size of the matrix and has very little dependency on the shape of the matrix, which is a significant improvement compared to the other three kernels that exhibit unstable performance behavior for different shapes of matrices.

  • S-Band GaN on Si Based 1kW-Class SSPA System for Space Wireless Applications

    Yuta KOBAYASHI  Satoshi YOSHIDA  Zen-ichi YAMAMOTO  Shigeo KAWASAKI  

     
    PAPER

      Vol:
    E96-C No:10
      Page(s):
    1245-1253

    An S-band GaN on Si based 1kW-class SSPA system for space wireless applications is proposed. Since high-efficiency and high-reliability amplifier is one of the most important technologies for power and communication systems in a future space base station on a planet, compact, high-power, and high-efficiency SSPA is strongly requested instead of TWTA. Thus, we adopt GaN on Si based amplifier due to its remarkable material properties. At the beginning, thermal vacuum and radiation test of GaN on Si are conducted so as to confirm the space applicability. Fabricated SSPA system consists of eight 200W HPAs and coaxial waveguide power combiner. It achieves high efficiency such as 57% of drain efficiency and 87% of combining efficiency when RF output power achieves more than 60dBm. Furthermore, long-term stable operation and good phase noise characteristics are also confirmed.

  • A 1µs Settling Time Fully Digital AGC System with a 1GHz-Bandwidth Variable Gain Amplifier for WiGig/IEEE802.11ad Multi-Gigabit Wireless Transceivers

    Ryo KITAMURA  Koichiro TANAKA  Tadashi MORITA  Takayuki TSUKIZAWA  Koji TAKINAMI  Noriaki SAITO  

     
    PAPER

      Vol:
    E96-C No:10
      Page(s):
    1301-1310

    This paper presents an automatic gain control (AGC) system suitable for 60GHz direct conversion receivers. By using a two step gain control algorithm with high-pass filter cutoff frequency switching, the proposed AGC system realizes fast settling time and wide dynamic range simultaneously. The paper also discusses wide-bandwidth variable gain amplifier (VGA) design. By introducing digitally-controlled resistors and gain flattening capacitors, the proposed VGA realizes wide gain range while compensating gain variations due to parasitic capacitance of MOS switches. The AGC system is implemented in a transceiver chipset where RFIC and BBIC are fabricated in 90nm CMOS and 40nm CMOS respectively. The measurement shows excellent dynamic range of 47dB with +/-1dB gain accuracy within 1µs settling time, which satisfies the stringent requirements of the IEEE802.11ad standard.

  • Sampling Signals with Finite Rate of Innovation and Recovery by Maximum Likelihood Estimation

    Akira HIRABAYASHI  Yosuke HIRONAGA  Laurent CONDAT  

     
    PAPER

      Vol:
    E96-A No:10
      Page(s):
    1972-1979

    We propose a maximum likelihood estimation approach for the recovery of continuously-defined sparse signals from noisy measurements, in particular periodic sequences of Diracs, derivatives of Diracs and piecewise polynomials. The conventional approach for this problem is based on least-squares (a.k.a. annihilating filter method) and Cadzow denoising. It requires more measurements than the number of unknown parameters and mistakenly splits the derivatives of Diracs into several Diracs at different positions. Moreover, Cadzow denoising does not guarantee any optimality. The proposed approach based on maximum likelihood estimation solves all of these problems. Since the corresponding log-likelihood function is non-convex, we exploit the stochastic method called particle swarm optimization (PSO) to find the global solution. Simulation results confirm the effectiveness of the proposed approach, for a reasonable computational cost.

  • Autocorrelation Values of Generalized Cyclotomic Sequences of Order Six

    Chun-e ZHAO  Wenping MA  Tongjiang YAN  Yuhua SUN  

     
    LETTER-Cryptography and Information Security

      Vol:
    E96-A No:10
      Page(s):
    2045-2048

    Binary sequences with low autocorrelation have important applications in communication systems and cryptography. In this paper, the autocorrelation values of binary Whiteman generalized cyclotomic sequences of order six and period pq are discussed. Our result shows that the autocorrelation of these sequences is four-valued and that the corresponding values are in {-1,3,-5,pq} if the parameters are chosen carefully.

  • A New Representation of Elements of Binary Fields with Subquadratic Space Complexity Multiplication of Polynomials

    Ferruh ÖZBUDAK  Sedat AKLEYLEK  Murat CENK  

     
    PAPER-General Fundamentals and Boundaries

      Vol:
    E96-A No:10
      Page(s):
    2016-2024

    In this paper, Hermite polynomial representation is proposed as an alternative way to represent finite fields of characteristic two. We show that multiplication in Hermite polynomial representation can be achieved with subquadratic space complexity. This representation enables us to find binomial or trinomial irreducible polynomials which allows us faster modular reduction over binary fields when there is no desirable such low weight irreducible polynomial in other representations. We then show that the product of two elements in Hermite polynomial representation can be performed as Toeplitz matrix-vector product. This representation is very interesting for NIST recommended binary field GF(2571) since there is no ONB for the corresponding extension. This representation can be used to obtain more efficient finite field arithmetic.

  • Performance Evaluation of Short-Range MIMO Using a Method for Controlling Phase Difference between Each Propagation Channel

    Kazumitsu SAKAMOTO  Ken HIRAGA  Tomohiro SEKI  Tadao NAKAGAWA  Kazuhiro UEHARA  

     
    PAPER-Adaptive Array Antennas/MIMO

      Vol:
    E96-B No:10
      Page(s):
    2513-2520

    A Simple decoding method for short-range MIMO (SR-MIMO) transmission can reduce the power consumption for MIMO decoding, but the distance between the transceivers requires millimeter-order accuracy in order to satisfy the required transmission quality. In this paper, we propose a phase difference control method between each propagation channel to alleviate the requirements for the transmission distance accuracy. In the proposed method, the phase difference between each propagation channel is controlled by changing the transmission (or received) power ratio of each element of sub-array antennas. In millimeter-wave broadband transmission simulation, we clarified that when sub-array antenna spacing is set to 6.6 mm and element spacing of sub-array antenna is set to 2.48mm, the proposed method can extend the transmission distance range satisfying the required transmission quality, which is that bit error rate (BER) before error correction is less than 10-2 from 9∼29mm to 0∼50mm in QPSK, from 15∼19mm to 0∼30mm in 16QAM, and from only 15mm to 4∼22mm in 64QAM.

  • A Proper Phase Shift in Multiple Linear Optical Teleportation

    Kazuto OSHIMA  

     
    LETTER-Fundamentals of Information Systems

      Vol:
    E96-D No:10
      Page(s):
    2266-2267

    In the Knill-Laflamme-Milburn (KLM) scheme, quantum teleportation is nearly deterministically carried out with linear optics. To reconstruct an original quantum state, however, a phase shift is required for an output state. We exhibit a proper phase shift to complete quantum teleportation.

  • Clinical Setup of Microwave Mammography

    Yoshihiko KUWAHARA  Saori MIURA  Yusuke NISHINA  Kaiji MUKUMOTO  Hiroyuki OGURA  Harumi SAKAHARA  

     
    PAPER-Sensing

      Vol:
    E96-B No:10
      Page(s):
    2553-2562

    A microwave mammography setup for clinical testing was developed and used to successfully carry out an initial clinical test. The equipment is based on multistatic ultra wideband (UWB) radar, which features a multistatic microwave imaging via space time (MS-MIST) algorithm for high resolution and a conformal array with an aspirator for fixing the breast in place. In this paper, an outline of the equipment, a numerical simulation, and clinical test results are presented.

  • Subarray-Processing Iterative SISO Multi-User Detection and Multi-Beam Directivity Control for Large-Scale Antenna Array in Quasi-Millimeter-Wave SDMA Systems

    Masaaki FUJII  Ji-Yun SEOL  TaeYoung KIM  JaeWeon CHO  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E96-B No:10
      Page(s):
    2650-2660

    A subarray signal processing scheme is described for a large-scale two-dimensional analog-digital hybrid beamformer to be used in quasi-millimeter-wave-band mobile communication systems. Multiple analog phased arrays direct their respective beams to multiple users, enabling space-division multiple access (SDMA). An iterative soft-input soft-output (SISO) multi-user detector recovers multi-user signals from subarray output signals corrupted by inter-user interference (IUI). In addition, a phased-array directivity control algorithm is derived based on inter-subarray signal phase-difference estimation from inter-beam-interference (IBI)-cancelled subarray output signals. Simulation results demonstrate that our proposed scheme achieves reduced hardware complexity, IUI-resistant multi-user signal detection, and IBI-resistant multi-user-tracking phased-array directivity control.

  • Cooperative Demodulation for Multiple Access Relay Systems with Network Coding

    Minjoong RIM  

     
    PAPER-Fundamental Theories for Communications

      Vol:
    E96-B No:10
      Page(s):
    2580-2586

    Multiple access relay systems with network coding provide spatial diversity with fewer transmissions. However, errors generated at the relay can propagate to the destination and the system performance can be severely degraded. Although many techniques have been proposed to resolve the error propagation, these techniques require some special operations at the relay or complicated reception schemes at the destination unless the global channel state information is available at the destination. This paper proposes a simple cooperative demodulation scheme for multiple access relay systems with network coding assuming that the relay simply forwards the decoded data and the destination has only the local channel state information.

  • New Negative Refractive Index Material Composed of Dielectric Prisms with Metal Patterns

    Hiroshi KUBO  Kazuhiro NISHIBAYASHI  Tsunayuki YAMAMOTO  Atsushi SANADA  

     
    PAPER

      Vol:
    E96-C No:10
      Page(s):
    1273-1280

    A two-dimensional negative refractive index material is proposed. The material has a bulky structure composed of dielectric prism cells with metal patterns. The material is expressed by an equivalent circuit. The propagation regions of two left-handed modes calculated from the equivalent circuit exist near the propagation regions obtained by electromagnetic simulation. It is confirmed by simulation that the incident plane wave goes into the material with low reflection by using the second left-handed mode and attaching metal conversion strips around the material. A negative refractive index slab lens with 15×9 cells is made to measure the field distribution of wave out of the lens. It is shown that the resolution of the slab lens exceeds the diffraction-limit.

  • Exploiting Group Sparsity in Nonlinear Acoustic Echo Cancellation by Adaptive Proximal Forward-Backward Splitting

    Hiroki KURODA  Shunsuke ONO  Masao YAMAGISHI  Isao YAMADA  

     
    PAPER

      Vol:
    E96-A No:10
      Page(s):
    1918-1927

    In this paper, we propose a use of the group sparsity in adaptive learning of second-order Volterra filters for the nonlinear acoustic echo cancellation problem. The group sparsity indicates sparsity across the groups, i.e., a vector is separated into some groups, and most of groups only contain approximately zero-valued entries. First, we provide a theoretical evidence that the second-order Volterra systems tend to have the group sparsity under natural assumptions. Next, we propose an algorithm by applying the adaptive proximal forward-backward splitting method to a carefully designed cost function to exploit the group sparsity effectively. The designed cost function is the sum of the weighted group l1 norm which promotes the group sparsity and a weighted sum of squared distances to data-fidelity sets used in adaptive filtering algorithms. Finally, Numerical examples show that the proposed method outperforms a sparsity-aware algorithm in both the system-mismatch and the echo return loss enhancement.

5341-5360hit(18690hit)