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[Keyword] PA(8249hit)

1401-1420hit(8249hit)

  • A Fully Canonical Bandpass Filter Design Using Microstrip Transversal Resonator Array Configuration

    Masataka OHIRA  Toshiki KATO  Zhewang MA  

     
    PAPER

      Vol:
    E99-C No:10
      Page(s):
    1122-1129

    This paper proposes a new and simple microstrip bandpass filter structure for the design of a fully canonical transversal array filter. The filter is constructed by the parallel arrangement of microstrip even- and odd-mode half-wavelength resonators. In this filter, transmission zeros (TZs) are not produced by cross couplings used in conventional filter designs, but by an intrinsic negative coupling of the odd-mode resonators having open ends with respect to the even-mode resonators with shorted ends. Thus, the control of the resonant frequency and the external Q factor of each resonator makes it possible to form both a specified passband and TZs. As an example, a fully canonical bandpass filter with 2-GHz center frequency, 6% bandwidth, and four TZs is synthesized with a coupling-matrix optimization, and its structural parameters are designed. The designed filter achieves a rapid roll-off and low-loss passband response, which can be confirmed numerically and experimentally.

  • Cooperative Path Selection Framework for Effective Data Gathering in UAV-Aided Wireless Sensor Networks

    Sotheara SAY  Mohamad Erick ERNAWAN  Shigeru SHIMAMOTO  

     
    PAPER

      Vol:
    E99-B No:10
      Page(s):
    2156-2167

    Sensor networks are often used to understand underlying phenomena that are reflected through sensing data. In real world applications, this understanding supports decision makers attempting to access a disaster area or monitor a certain event regularly and thus necessary actions can be triggered in response to the problems. Practitioners designing such systems must overcome difficulties due to the practical limitations of the data and the fidelity of a network condition. This paper explores the design of a network solution for the data acquisition domain with the goal of increasing the efficiency of data gathering efforts. An unmanned aerial vehicle (UAV) is introduced to address various real-world sensor network challenges such as limited resources, lack of real-time representative data, and mobility of a relay station. Towards this goal, we introduce a novel cooperative path selection framework to effectively collect data from multiple sensor sources. The framework consists of six main parts ranging from the system initialization to the UAV data acquisition. The UAV data acquisition is useful to increase situational awareness or used as inputs for data manipulation that support response efforts. We develop a system-based simulation that creates the representative sensor networks and uses the UAV for collecting data packets. Results using our proposed framework are analyzed and compared to existing approaches to show the efficiency of the scheme.

  • Deforming Pyramid: Multiscale Image Representation Using Pixel Deformation and Filters for Non-Equispaced Signals

    Saho YAGYU  Akie SAKIYAMA  Yuichi TANAKA  

     
    PAPER

      Vol:
    E99-A No:9
      Page(s):
    1646-1654

    We propose an edge-preserving multiscale image decomposition method using filters for non-equispaced signals. It is inspired by the domain transform, which is a high-speed edge-preserving smoothing method, and it can be used in many image processing applications. One of the disadvantages of the domain transform is sensitivity to noise. Even though the proposed method is based on non-equispaced filters similar to the domain transform, it is robust to noise since it employs a multiscale decomposition. It uses the Laplacian pyramid scheme to decompose an input signal into the piecewise-smooth components and detail components. We design the filters by using an optimization based on edge-preserving smoothing with a conversion of signal distances and filters taking into account the distances between signal intervals. In addition, we also propose construction methods of filters for non-equispaced signals by using arbitrary continuous filters or graph spectral filters in order that various filters can be accommodated by the proposed method. As expected, we find that, similar to state-of-the-art edge-preserving smoothing techniques, including the domain transform, our approach can be used in many applications. We evaluated its effectiveness in edge-preserving smoothing of noise-free and noisy images, detail enhancement, pencil drawing, and stylization.

  • Sparse-Graph Codes and Peeling Decoder for Compressed Sensing

    Weijun ZENG  Huali WANG  Xiaofu WU  Hui TIAN  

     
    LETTER-Digital Signal Processing

      Vol:
    E99-A No:9
      Page(s):
    1712-1716

    In this paper, we propose a compressed sensing scheme using sparse-graph codes and peeling decoder (SGPD). By using a mix method for construction of sensing matrices proposed by Pawar and Ramchandran, it generates local sensing matrices and implements sensing and signal recovery in an adaptive manner. Then, we show how to optimize the construction of local sensing matrices using the theory of sparse-graph codes. Like the existing compressed sensing schemes based on sparse-graph codes with “good” degree profile, SGPD requires only O(k) measurements to recover a k-sparse signal of dimension n in the noiseless setting. In the presence of noise, SGPD performs better than the existing compressed sensing schemes based on sparse-graph codes, still with a similar implementation cost. Furthermore, the average variable node degree for sensing matrices is empirically minimized for SGPD among various existing CS schemes, which can reduce the sensing computational complexity.

  • Optimal Gaussian Weight Predictor and Sorting Using Genetic Algorithm for Reversible Watermarking Based on PEE and HS

    Chaiyaporn PANYINDEE  Chuchart PINTAVIROOJ  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2016/06/03
      Vol:
    E99-D No:9
      Page(s):
    2306-2319

    This paper introduces a reversible watermarking algorithm that exploits an adaptable predictor and sorting parameter customized for each image and each payload. Our proposed method relies on a well-known prediction-error expansion (PEE) technique. Using small PE values and a harmonious PE sorting parameter greatly decreases image distortion. In order to exploit adaptable tools, Gaussian weight predictor and expanded variance mean (EVM) are used as parameters in this work. A genetic algorithm is also introduced to optimize all parameters and produce the best results possible. Our results show an improvement in image quality when compared with previous conventional works.

  • Robust Non-Parametric Template Matching with Local Rigidity Constraints

    Chao ZHANG  Haitian SUN  Takuya AKASHI  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2016/06/03
      Vol:
    E99-D No:9
      Page(s):
    2332-2340

    In this paper, we address the problem of non-parametric template matching which does not assume any specific deformation models. In real-world matching scenarios, deformation between a template and a matching result usually appears to be non-rigid and non-linear. We propose a novel approach called local rigidity constraints (LRC). LRC is built based on an assumption that the local rigidity, which is referred to as structural persistence between image patches, can help the algorithm to achieve better performance. A spatial relation test is proposed to weight the rigidity between two image patches. When estimating visual similarity under an unconstrained environment, high-level similarity (e.g. with complex geometry transformations) can then be estimated by investigating the number of LRC. In the searching step, exhaustive matching is possible because of the simplicity of the algorithm. Global maximum is given out as the final matching result. To evaluate our method, we carry out a comprehensive comparison on a publicly available benchmark and show that our method can outperform the state-of-the-art method.

  • Decode-and-Forward Cooperative Transmission with a Multi-Antenna Relay in Multiuser Networks

    Chang Kyung SUNG  Kyu-Sung HWANG  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2016/04/04
      Vol:
    E99-B No:9
      Page(s):
    2062-2071

    In this paper, we consider a two-hop relay network with a decode-and-forward (DF) relaying protocol where a multi-input/multi-output (MIMO) relay station (RS) is deployed in a cell edge to extend cell coverage of a base station (BS). We propose two MIMO relaying schemes to improve the quality of the BS-RS link, which is a key to improve data rates in the DF relaying: 1) spatial multiplexed MIMO antenna relaying (SM-MAR) with a uniform channel decomposition (UCD) precoder, and 2) MIMO relaying with section diversity (SD-MAR). In the SM-MAR, we greatly simplify user allocation by the UCD precoder and propose a sophisticated rate maximization technique to resolve the non-convexity of rate maximization problems. Through simulations, we show that the proposed UCD based power allocation exhibits up to two times higher achievable throughput than other techniques. In addition, the proposed SD-MAR supports the BS with a single transmit antenna and increases the signal quality of the BS-RS link with the selection diversity at the RS, which is much simpler to be implemented. For the SD-MAR, we derive a closed form expression for the achievable throughput and show that the selection diversity plays more important role on the achievable throughput than the multiuser diversity.

  • The Reliability Analysis of the 1-out-of-2 System in Which Two Modules Do Mutual Cooperation in Recovery Mode

    Aromhack SAYSANASONGKHAM  Satoshi FUKUMOTO  

     
    LETTER-Reliability, Maintainability and Safety Analysis

      Vol:
    E99-A No:9
      Page(s):
    1730-1734

    In this research, we investigated the reliability of a 1-out-of-2 system with two-stage repair comprising hardware restoration and data reconstruction modes. Hardware restoration is normally independently executed by two modules. In contrast, we assumed that one of the modules could omit data reconstruction by replicating the data from the module during normal operation. In this 1-out-of-2 system, the two modules mutually cooperated in the recovery mode. As a first step, an evaluation model using Markov chains was constructed to derive a reliability measure: “unavailability in steady state.” Numerical examples confirmed that the reliability of the system was improved by the use of two cooperating modules. As the data reconstruction time increased, the gains in terms of system reliability also increased.

  • Efficiency Analysis of SiC-MOSFET-Based Bidirectional Isolated DC/DC Converters

    Atsushi SAITO  Kenshiro SATO  Yuta TANIMOTO  Kai MATSUURA  Yutaka SASAKI  Mitiko MIURA-MATTAUSCH  Hans Jürgen MATTAUSCH  Yoshifumi ZOKA  

     
    PAPER-Electronic Circuits

      Vol:
    E99-C No:9
      Page(s):
    1065-1070

    Circuit performance of SiC-MOSFET-based bidirectional isolated DC/DC converters is investigated based on circuit simulation with the physically accurate compact device model HiSIM_HV. It is demonstrated that the combined optimization of the MOSFETs Ron and of the inductances in the transformer can enable a conversion efficiency of more than 97%. The simulation study also verifies that the possible efficiency improvements are diminished due to the MOSFET-performance degradation, namely the carrier-mobility reduction, which results in a limitation of the possible Ron reduction. It is further demonstrated that an optimization of the MOSFET-operation conditions is important to utilize the resulting higher MOSFET performance for achieving additional converter efficiency improvements.

  • Analysis over Spectral Efficiency and Power Scaling in Massive MIMO Dual-Hop Systems with Multi-Pair Users

    Yi WANG  Baofeng JI  Yongming HUANG  Chunguo LI  Ying HU  Yewang QIAN  Luxi YANG  

     
    PAPER-Information Theory

      Vol:
    E99-A No:9
      Page(s):
    1665-1673

    This paper considers a massive multiple-input-multiple-output (MIMO) relaying system with multi-pair single-antenna users. The relay node adopts maximum-ratio combining/maximum-ratio transmission (MRC/MRT) stratagem for reception/transmission. We analyze the spectral efficiency (SE) and power scaling laws with respect to the number of relay antennas and other system parameters. First, by using the law of large numbers, we derive the closed-form expression of the SE, based on which, it is shown that the SE per user increases with the number of relay antennas but decreases with the number of user pairs, both logarithmically. It is further discovered that the transmit power at the source users and the relay can be continuously reduced as the number of relay antennas becomes large while the SE can maintains a constant value, which also means that the energy efficiency gain can be obtained simultaneously. Moreover, it is proved that the number of served user pairs can grow proportionally over the number of relay antennas with arbitrary SE requirement and no extra power cost. All the analytical results are verified through the numerical simulations.

  • High-Capacity Wireless Access Networks Using 920MHz Band for Wide-Area IoT/M2M Services Open Access

    Kazunori AKABANE  Nobuaki MOCHIZUKI  Shigeru TERUHI  Mamoru KOBAYASHI  Shuichi YOSHINO  Masashi SHIMIZU  Kazuhiro UEHARA  

     
    INVITED PAPER

      Vol:
    E99-B No:9
      Page(s):
    1920-1929

    In the near future, many sensors and terminals will be connected to the public network to provide various convenient IoT/M2M services. In order to connect many sensors to the network efficiently, wireless communication systems in the 920MHz band are seen as attractive solutions. We are focusing on the 920MHz band to research and develop high-capacity protocols that can accommodate many terminals, and low power consumption technologies for battery-driven terminals. In this paper, we describe the following three concrete wireless systems that use our proposals. (1) A physical distribution pallet management system that can handle thousands of pallet-embedded sensors and a wireless module with a battery lifetime of about ten years. (2) Water leakage monitoring system for underground pipes by using sensors and a wireless module in each valve box. (3) A wide-area and high-capacity radio relay system for smart metering services like the reading of gas meters. The radio relay system can accommodate various sensors and terminals and has large potential for providing various IoT/M2M services in conjunction with smart metering services.

  • An Improved PSO Algorithm for Interval Multi-Objective Optimization Systems

    Yong ZHANG  Wanqiu ZHANG  Dunwei GONG  Yinan GUO  Leida LI  

     
    LETTER-Fundamentals of Information Systems

      Pubricized:
    2016/06/01
      Vol:
    E99-D No:9
      Page(s):
    2381-2384

    Considering an uncertain multi-objective optimization system with interval coefficients, this letter proposes an interval multi-objective particle swarm optimization algorithm. In order to improve its performance, a crowding distance measure based on the distance and the overlap degree of intervals, and a method of updating the archive based on the acceptance coefficient of decision-maker, are employed. Finally, results show that our algorithm is capable of generating excellent approximation of the true Pareto front.

  • A Search-Based Constraint Elicitation in Test Design

    Hiroyuki NAKAGAWA  Tatsuhiro TSUCHIYA  

     
    PAPER

      Pubricized:
    2016/07/06
      Vol:
    E99-D No:9
      Page(s):
    2229-2238

    Pair-wise testing is an effective test planning technique for finding interaction faults using a small set of test cases. Constraint elicitation is an important process in the pair-wise testing design since constraints determine the test space; however, the constraint elicitation process has not been well studied. It usually requires manual capturing and precise definition of constraints. In this paper, we propose a constraint elicitation process that helps combinatorial test design. Our elicitation process consists of two steps: parameter combination identification and value pair determination. We conduct experiments on some test models, and demonstrate that some extracted rules match constraints and others helps to define constraints.

  • Incremental Semantic Construction Based on Combinatory Categorial Grammar

    Yoshihide KATO  Shigeki MATSUBARA  

     
    PAPER-Natural Language Processing

      Pubricized:
    2016/06/02
      Vol:
    E99-D No:9
      Page(s):
    2368-2376

    This paper proposes a method of incrementally constructing semantic representations. Our method is based on Steedman's Combinatory Categorial Grammar (CCG), which has a transparent correspondence between syntax and semantics. In our method, a derivation for a sentence is constructed in an incremental fashion and the corresponding semantic representation is derived synchronously. Our method uses normal form CCG derivation. This is the difference between our approach and previous ones. Previous approaches use most left-branching derivation called incremental derivation, but they cannot process coordinate structures incrementally. Our method overcomes this problem.

  • Blind Carrier Frequency Offset Estimation Based on Particle Swarm Optimization Searching for Interleaved OFDMA Uplink

    Ann-Chen CHANG  Chih-Chang SHEN  

     
    LETTER-Communication Theory and Signals

      Vol:
    E99-A No:9
      Page(s):
    1740-1744

    In this letter, standard particle swarm optimization (PSO) with the center-symmetric trimmed correlation matrix and the orthogonal projection technique is firstly presented for blind carrier frequency offset estimation under interleaved orthogonal frequency division multiple access (OFDMA) uplink systems. It doesn't require eigenvalue decomposition and only needs a single OFDMA data block. Second, this letter also presents adaptive multiple inertia weights with Newton method to speed up the convergence of standard PSO iteration process. Meanwhile, the advantage of inherent interleaved OFDMA signal structure also is exploited to conquer the problems of local optimization and the effect of ambiguous peaks for the proposed approaches. Finally, several simulation results are provided for illustration and comparison.

  • Singular-Spectrum Analysis for Digital Audio Watermarking with Automatic Parameterization and Parameter Estimation Open Access

    Jessada KARNJANA  Masashi UNOKI  Pakinee AIMMANEE  Chai WUTIWIWATCHAI  

     
    PAPER-Information Network

      Pubricized:
    2016/05/16
      Vol:
    E99-D No:8
      Page(s):
    2109-2120

    This paper proposes a blind, inaudible, robust digital-audio watermarking scheme based on singular-spectrum analysis, which relates to watermarking techniques based on singular value decomposition. We decompose a host signal into its oscillatory components and modify amplitudes of some of those components with respect to a watermark bit and embedding rule. To improve the sound quality of a watermarked signal and still maintain robustness, differential evolution is introduced to find optimal parameters of the proposed scheme. Test results show that, although a trade-off between inaudibility and robustness still persists, the difference in sound quality between the original and the watermarked one is considerably smaller. This improved scheme is robust against many attacks, such as MP3 and MP4 compression, and band-pass filtering. However, there is a drawback, i.e., some music-dependent parameters need to be shared between embedding and extraction processes. To overcome this drawback, we propose a method for automatic parameter estimation. By incorporating the estimation method into the framework, those parameters need not to be shared, and the test results show that it can blindly decode watermark bits with an accuracy of 99.99%. This paper not only proposes a new technique and scheme but also discusses the singular value and its physical interpretation.

  • Self-Adaptive Scaled Min-Sum Algorithm for LDPC Decoders Based on Delta-Min

    Keol CHO  Ki-Seok CHUNG  

     
    LETTER-Coding Theory

      Vol:
    E99-A No:8
      Page(s):
    1632-1634

    A self-adaptive scaled min-sum algorithm for LDPC decoding based on the difference between the first two minima of the check node messages (Δmin) is proposed. Δmin is utilized for adjusting the scaling factor of the check node messages, and simulation results show that the proposed algorithm improves the error correcting performance compared to existing algorithms.

  • Rapid Restoration Sequence of Fiber Links and Communication Paths from Catastrophic Failures

    Akihiro KADOHATA  Takafumi TANAKA  Wataru IMAJUKU  Fumikazu INUZUKA  Atsushi WATANABE  

     
    PAPER

      Vol:
    E99-A No:8
      Page(s):
    1510-1517

    This paper addresses the issue of implementing a sequence for restoring fiber links and communication paths that have failed due to a catastrophe. We present a mathematical formulation to minimize the total number of steps needed to restore communication paths. We also propose two heuristic algorithms: Minimum spanning tree - based degree order restoration and Congestion link order restoration. Numerical evaluations show that integer linear programming based order restoration yields the fewest number of restoration steps, and that the proposed heuristic algorithms, when used properly with regard to the accommodation rate, are highly effective for real-world networks.

  • Data Association in Bistatic MIMO of T/R-R Mode: Basis Decision and Performance Analysis

    Xiang DUAN  Zishu HE  Hongming LIU  Jun LI  

     
    PAPER-Digital Signal Processing

      Vol:
    E99-A No:8
      Page(s):
    1567-1575

    Bistatic multi-input multi-output (MIMO) radar has the capability of measuring the transmit angle from the receiving array, which means the existence of information redundancy and benefits data association. In this paper, a data association decision for bistatic MIMO radar is proposed and the performance advantages of bistatic MIMO radar in data association is analyzed and evaluated. First, the parameters obtained by receiving array are sent to the association center via coordinate conversion. Second, referencing the nearest neighbor association (NN) algorithm, an improved association decision is proposed with the transmit angle and target range as association statistics. This method can evade the adverse effects of the angle system errors to data association. Finally, data association probability in the presence of array directional error is derived and the correctness of derivation result is testified via Monte Carlo simulation experiments. Besides that performance comparison with the conventional phased array radar verifies the excellent performance of bistatic MIMO Radar in data association.

  • Business Recovery Conditions of Private Enterprises after the 2011 Great East Japan Earthquake and Issues on Business Continuity Measures for Large-Scale Disaster Management — A Case Study of Small and Medium-Sized Enterprises in Miyagi —

    Norimasa NAKATANI  Osamu MURAO  Kimiro MEGURO  Kiyomine TERUMOTO  

     
    PAPER

      Vol:
    E99-A No:8
      Page(s):
    1539-1550

    Forming Business Continuity Planning (BCP) is recognized as a significant counter-measure against future large-scale disasters by private enterprises after the 2011 Great East Japan Earthquake more than before. Based on a questionnaire survey, this paper reports business recovery conditions of private enterprises in Miyagi Prefecture affected by the disaster. Analyzing the results of questionnaire, it suggests some important points: (1) estimation of long-term internal/external factors that influence business continuity, (2) development of concrete pre-disaster framework, (3) multi-media-based advertising strategy, and (4) re-allocation of resources.

1401-1420hit(8249hit)