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521-540hit(5768hit)

  • Two-Level Named Packet Forwarding for Enhancing the Performance of Virtualized ICN Router

    Kazuaki UEDA  Kenji YOKOTA  Jun KURIHARA  Atsushi TAGAMI  

     
    PAPER

      Pubricized:
    2019/03/22
      Vol:
    E102-B No:9
      Page(s):
    1813-1821

    Information-Centric Networking (ICN) can offer rich functionalities to the network, e.g, in-network caching, and name-based forwarding. Incremental deployment of ICN is a key challenge that enable smooth migration from current IP network to ICN. We can say that Network Function Virtualization (NFV) must be one of the key technologies to achieve this deployment because of its flexibility to support new network functions. However, when we consider the ICN deployment with NFV, there exist two performance issues, processing delay of name-based forwarding and computational overhead of virtual machine. In this paper we proposed a NFV infrastructure-assisted ICN packet forwarding by integrating the name look-up to the Open vSwitch. The contributions are twofold: 1) First, we provide the novel name look-up scheme that can forward ICN packets without costly longest prefix match searching. 2) Second, we design the ICN packet forwarding scheme that integrates the partial name look-up into the virtualization infrastructure to mitigate computation overhead.

  • Consideration of Relationship between Human Preference and Pulse Wave Derived from Brain Activity

    Mami KITABATA  Yota NIIGAKI  Yuukou HORITA  

     
    LETTER

      Vol:
    E102-A No:9
      Page(s):
    1250-1253

    In this paper, we consider the relationship between human preference and brain activity, especially pulse wave information using NIRS. First of all, we extracted the information of on pulse wave from the Hb changes signal of NIRS. By using the FFT to the Hb signals, we found out the 2-nd peak of power spectrum that is implying the frequency information of the pulse wave. The frequency deviation of 2-nd peak may have some information about the change of brain activity, it is associated with the human preference for viewing the significant image content.

  • Dynamic Throughput Allocation among Multiple Servers for Heterogeneous Storage System

    Zhisheng HUO  Limin XIAO  Zhenxue HE  Xiaoling RONG  Bing WEI  

     
    PAPER-Computer System

      Pubricized:
    2019/05/27
      Vol:
    E102-D No:9
      Page(s):
    1731-1739

    Previous works have studied the throughput allocation of the heterogeneous storage system consisting of SSD and HDD in the dynamic setting where users are not all present in the system simultaneously, but those researches make multiple servers as one large resource pool, and cannot cope with the multi-server environment. We design a dynamic throughput allocation mechanism named DAM, which can handle the throughput allocation of multiple heterogeneous servers in the dynamic setting, and can provide a number of desirable properties. The experimental results show that DAM can make one dynamic throughput allocation of multiple servers for making sure users' local allocations in each server, and can provide one efficient and fair throughput allocation in the whole system.

  • A Feasibility Study on the Safety Confirmation System Using NFC and UHF Band RFID Tags

    Shigeki TAKEDA  Kenichi KAGOSHIMA  Masahiro UMEHIRA  

     
    LETTER-System Construction Techniques

      Pubricized:
    2019/06/04
      Vol:
    E102-D No:9
      Page(s):
    1673-1675

    This letter presents the safety confirmation system based on Near Field Communication (NFC) and Ultra High Frequency (UHF) band Radio Frequency IDentification (RFID) tags. Because these RFID tags can operate without the need for internal batteries, the proposed safety confirmation system is effective during large-scale disasters that cause loss of electricity and communication infrastructures. Sharing safety confirmation data between the NFC and UHF band RFID tags was studied to confirm the feasibility of the data sharing. The prototype of the proposed system was fabricated, confirming the feasibility of the proposed safety confirmation system.

  • On the Optimality of Gabidulin-Based LRCs as Codes with Multiple Local Erasure Correction Open Access

    Geonu KIM  Jungwoo LEE  

     
    LETTER-Coding Theory

      Vol:
    E102-A No:9
      Page(s):
    1326-1329

    The Gabidulin-based locally repairable code (LRC) construction by Silberstein et al. is an important example of distance optimal (r,δ)-LRCs. Its distance optimality has been further shown to cover the case of multiple (r,δ)-locality, where the (r,δ)-locality constraints are different among different symbols. However, the optimality only holds under the ordered (r,δ) condition, where the parameters of the multiple (r,δ)-locality satisfy a specific ordering condition. In this letter, we show that Gabidulin-based LRCs are still distance optimal even without the ordered (r,δ) condition.

  • Opcount: A Pseudo-Code Performance Estimation System for Pairing-Based Cryptography Open Access

    Masayuki ABE  Fumitaka HOSHINO  Miyako OHKUBO  

     
    PAPER-Cryptography and Information Security

      Vol:
    E102-A No:9
      Page(s):
    1285-1292

    We propose a simple framework for evaluating the performance of pairing-based cryptographic schemes for various types of curves and parameter settings. The framework, which we call ‘Opcount’, enables the selection of an appropriate curve and parameters by estimating the performance of a cryptographic scheme from a pseudo-code describing the cryptographic scheme and an implementation-information database that records the performance of basic operations in curves targeted for evaluation. We apply Opcount to evaluate and compare the computational efficiency of several structure-preserving signature schemes that involve tens of pairing products in their signature verification. In addition to showing the usefulness of Opcount, our experiments also reveal the overlooked importance of taking account of the properties of underlying curves when optimizing computations and demonstrate the impact of tight security reductions.

  • A Heuristic Algorithm for Solving the Aircraft Landing Scheduling Problem with a Landing Sequence Division Open Access

    Wen SHI  Shan JIANG  Xuan LIANG  Na ZHOU  

     
    PAPER-Intelligent Transport System

      Vol:
    E102-A No:8
      Page(s):
    966-973

    Aircraft landing scheduling (ALS) is one of the most important challenges in air traffic management. The target of ALS is to decide a landing scheduling sequence and calculate a landing time for each aircraft in terminal areas. These landing times are within time windows, and safety separation distances between aircraft must be kept. ALS is a complex problem, especially with a large number of aircraft. In this study, we propose a novel heuristic called CGIC to solve ALS problems. The CGIC consists of four components: a chunking rule based on costs, a landing subsequence generation rule, a chunk improvement heuristic, and a connection rule. In this algorithm, we reduce the complexity of the ALS problem by breaking it down into two or more subproblems with less aircraft. First, a feasible landing sequence is generated and divided into several subsequences as chunks by a chunking rule based on aircraft cost. Second, each chunk is regenerated by a constructive heuristic, and a perturbative heuristic is applied to improve the chunks. Finally, all chunks constitute a feasible landing sequence through a connection rule, and the landing time of each aircraft is calculated on the basis of this sequence. Simulations demonstrate that (a) the chunking rule based on cost outperforms other chunking rules based on time or weight for ALS in static instances, which have a large number of aircraft; (b) the proposed CGIC can solve the ALS problem up to 500 aircraft optimally; (c) in dynamic instances, CGIC can obtain high-quality solutions, and the computation time of CGIC is low enough to enable real-time execution.

  • Iris Segmentation Based on Improved U-Net Network Model

    Chunhui GAO  Guorui FENG  Yanli REN  Lizhuang LIU  

     
    LETTER-Neural Networks and Bioengineering

      Vol:
    E102-A No:8
      Page(s):
    982-985

    Accurate segmentation of the region in the iris picture has a crucial influence on the reliability of the recognition system. In this letter, we present an end to end deep neural network based on U-Net. It uses dense connection blocks to replace the original convolutional layer, which can effectively improve the reuse rate of the feature layer. The proposed method takes U-net's skip connections to combine the same-scale feature maps from the upsampling phase and the downsampling phase in the upsampling process (merge layer). In the last layer of downsampling, it uses dilated convolution. The dilated convolution balances the iris region localization accuracy and the iris edge pixel prediction accuracy, further improving network performance. The experiments running on the Casia v4 Interval and IITD datasets, show that the proposed method improves segmentation performance.

  • Dual Polarized Cylindrical Loop Slot Antenna for Omni Cell Application

    Bakar ROHANI  Ryosuke KANEDA  Hiroyuki ARAI  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2019/02/12
      Vol:
    E102-B No:8
      Page(s):
    1668-1675

    Urban area suffers severe multipath effects due to its complex infrastructure environment and sector antenna is a popular choice as a base station antenna in those areas. Within sector antennas, omni cell antenna is utilized as supporting antenna to cover low reception areas between them. This paper proposes a slant 45° dual polarized omnidirectional antenna to operate as the omni cell antenna in those environments. The frequency band covers the IMT band, ranging from 1920MHz to 2170MHz with directivity focusing in horizontal plane. The antenna structure consists of a loop slot antenna array as excitation element which is placed inside a cylindrical slot antenna as parasitic element. Good performance is achieved in both S-parameter and directivity results, with a gain of more than 4 dBi and a gain difference of less than 1.5dB. The measurement results also agree well with the simulation results and the final design confirms that the proposed antenna works effectively as a slant ±45 ° dual polarized omnidirectional antenna.

  • Performance of Iterative Digital Self-Interference Canceler with Alternating Estimate Subtraction for OFDM Using Full Duplex

    Takahiro OHTOMO  Hiroki YAMADA  Mamoru SAWAHASHI  Keisuke SAITO  

     
    PAPER

      Pubricized:
    2019/02/20
      Vol:
    E102-B No:8
      Page(s):
    1490-1502

    In full duplex (FD), which improves the system capacity (or cell throughput) and reduces the transmission delay (or latency) through simultaneous transmission and reception in the same frequency band, self-interference (SI) from the transmitter should be suppressed using antenna isolation, an analog SI canceler, and digital SI canceler (DSIC) to a level such that the data or control channel satisfies the required block error rate (BLER). This paper proposes a structure of iterative DSIC with alternating estimate subtraction (AES-IDSIC) for orthogonal frequency division multiplexing (OFDM) using FD. We first present the required SI suppression level considering SI, quantization noise of an analog-to-digital converter, and nonlinear distortion of a power amplifier and RF receiver circuit for a direct conversion transceiver using FD. Then, we propose an AES-IDSIC structure that iterates the generation of the SI estimate, the downlink symbol estimate, and then alternately removes one of the estimates from the received signal in the downlink including SI. We investigate the average BLER performance of the AES-IDSIC for OFDM using FD in a multipath fading channel based on link-level simulations under the constraint that the derived required signal-to-SI ratio must be satisfied.

  • Learning-Based, Distributed Spectrum Observation System for Dynamic Spectrum Sharing in the 5G Era and Beyond

    Masaki KITSUNEZUKA  Kenta TSUKAMOTO  Jun SAKAI  Taichi OHTSUJI  Kazuaki KUNIHIRO  

     
    PAPER

      Pubricized:
    2019/02/20
      Vol:
    E102-B No:8
      Page(s):
    1526-1537

    Dynamic sharing of limited radio spectrum resources is expected to satisfy the increasing demand for spectrum resources in the upcoming 5th generation mobile communication system (5G) era and beyond. Distributed real-time spectrum sensing is a key enabler of dynamic spectrum sharing, but the costs incurred in observed-data transmission are a critical problem, especially when massive numbers of spectrum sensors are deployed. To cope with this issue, the proposed spectrum sensors learn the ambient radio environment in real-time and create a time-spectral model whose parameters are shared with servers operating in the edge-computing layer. This process makes it possible to significantly reduce the communication cost of the sensors because frequent data transmission is no longer needed while enabling the edge servers to keep up on the current status of the radio environment. On the basis of the created time-spectral model, sharable spectrum resources are dynamically harvested and allocated in terms of geospatial, temporal, and frequency-spectral domains when accepting an application for secondary-spectrum use. A web-based prototype spectrum management system has been implemented using ten servers and dozens of sensors. Measured results show that the proposed approach can reduce data traffic between the sensors and servers by 97%, achieving an average data rate of 10 kilobits per second (kbps). In addition, the basic operation flow of the prototype has been verified through a field experiment conducted at a manufacturing facility and a proof-of-concept experiment of dynamic-spectrum sharing using wireless local-area-network equipment.

  • Green Resource Allocation in OFDMA Networks with Opportunistic Beamforming-Based DF Relaying

    Tao WANG  Mingfang WANG  Yating WU  Yanzan SUN  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2019/02/04
      Vol:
    E102-B No:8
      Page(s):
    1715-1727

    This paper proposes an energy efficiency (EE) maximized resource allocation (RA) algorithm in orthogonal frequency division multiple access (OFDMA) downlink networks with multiple relays, where a novel opportunistic subcarrier pair based decode-and-forward (DF) protocol with beamforming is used. Specifically, every data transmission is carried out in two consecutive time slots. During every transmission, multiple parallel paths, including relayed paths and direct paths, are established by the proposed RA algorithm. As for the protocol, each subcarrier in the 1st slot can be paired with any subcarrier in 2nd slot to best utilize subcarrier resources. Furthermore, for each relayed path, multiple (not just single or all) relays can be chosen to apply beamforming at the subcarrier in the 2nd slot. Each direct path is constructed by an unpaired subcarrier in either the 1st or 2nd slot. In order to guarantee an acceptable spectrum efficiency, we also introduce a minimum rate constraint. The EE-maximized problem is a highly nonlinear optimization problem, which contains both continuous, discrete variables and has a fractional structure. To solve the problem, the best relay set and resource allocation for a relayed path are derived first, then we design an iterative algorithm to find the optimal RA for the network. Finally, numerical experiments are taken to demonstrate the effectiveness of the proposed algorithm, and show the impact of minimum rate requirement, user number and circuit power on the network EE.

  • New Model of Flaming Phenomena in On-Line Social Networks Caused by Degenerated Oscillation Modes

    Takahiro KUBO  Chisa TAKANO  Masaki AIDA  

     
    PAPER-Fundamental Theories for Communications

      Pubricized:
    2019/01/24
      Vol:
    E102-B No:8
      Page(s):
    1554-1564

    The explosive dynamics present in on-line social networks, typically represented by flaming phenomena, can have a serious impact on not only the sustainable operation of information networks but also on activities in the real world. In order to counter the flaming phenomenon, it is necessary to understand the mechanism underlying the generation of the flaming phenomena within an engineering framework. This paper discusses a new model of the generating mechanism of the flaming phenomena. Our previous study has shown that the cause of flaming phenomena can, by reference to an oscillation model on networks, be understood complex eigenvalues of the matrix formed to describe oscillating phenomena. In this paper, we show that the flaming phenomena can occur due to coupling between degenerated oscillation modes even if all the eigenvalues are real numbers. In addition, we investigate the generation process of flaming phenomena with respect to the initial phases of the degenerated oscillation modes.

  • Localization Method Using Received Signal Strength for Wireless Power Transmission of the Capsule Endoscope Open Access

    Daijiro HIYOSHI  Masaharu TAKAHASHI  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2019/02/18
      Vol:
    E102-B No:8
      Page(s):
    1660-1667

    In recent years, capsule endoscopy has attracted attention as one of the medical devices that examine internal digestive tracts without burdening patients. Wireless power transmission of the capsule endoscope has been researched now, and the power transmission efficiency can be improved by knowing the capsule location. In this paper, we develop a localization method wireless power transmission. Therefore, a simple algorithm for using received signal strength (RSS) has been developed so that position estimation can be performed in real time, and the performance is evaluated by performing three-dimensional localization with eight receiving antennas.

  • Path Loss Model in Crowded Outdoor Environments Considering Multiple Human Body Shadowing of Multipath at 4.7GHz and 26.4GHz

    Mitsuki NAKAMURA  Motoharu SASAKI  Wataru YAMADA  Naoki KITA  Takeshi ONIZAWA  Yasushi TAKATORI  Masashi NAKATSUGAWA  Minoru INOMATA  Koshiro KITAO  Tetsuro IMAI  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2019/02/12
      Vol:
    E102-B No:8
      Page(s):
    1676-1688

    This paper proposes a path loss model for crowded outdoor environments that can consider the density of people. Measurement results in an anechoic chamber with three blocking persons showed that multiple human body shadowing can be calculated by using finite width screens. As a result, path loss in crowded environments can be calculated by using the path losses of the multipath and the multiple human body shadowing on those paths. The path losses of the multipath are derived from a ray tracing simulation, and the simulation results are then used to predict the path loss in crowded environments. The predicted path loss of the proposed model was examined through measurements in the crowded outdoor station square in front of Shibuya Station in Tokyo, and results showed that it can accurately predict the path loss in crowded environments at the frequencies of 4.7GHz and 26.4GHz under two different conditions of antenna height and density of people. The RMS error of the proposed model was less than 4dB.

  • AN-Aided Transmission Design for Secure MIMO Cognitive Radio Network with SWIPT

    Xinyu DA  Lei NI  Hehao NIU  Hang HU  Shaohua YUE  Miao ZHANG  

     
    PAPER-Cryptography and Information Security

      Vol:
    E102-A No:8
      Page(s):
    946-952

    In this work, we investigate a joint transmit beamforming and artificial noise (AN) covariance matrix design in a multiple-input multiple-output (MIMO) cognitive radio (CR) downlink network with simultaneous wireless information and power transfer (SWIPT), where the malicious energy receivers (ERs) may decode the desired information and hence can be treated as potential eavesdroppers (Eves). In order to improve the secure performance of the transmission, AN is embedded to the information-bearing signal, which acts as interference to the Eves and provides energy to all receivers. Specifically, this joint design is studied under a practical non-linear energy harvesting (EH) model, our aim is to maximize the secrecy rate at the SR subject to the transmit power budget, EH constraints and quality of service (QoS) requirement. The original problem is not convex and challenging to be solved. To circumvent its intractability, an equivalent reformulation of this secrecy rate maximization (SRM) problem is introduced, wherein the resulting problem is primal decomposable and thus can be handled by alternately solving two convex subproblems. Finally, numerical results are presented to verify the effectiveness of our proposed scheme.

  • A Study on Hop Count Reduction of Frame Transfer in ZigBee Network by Wireless LAN Cooperation

    Yosuke TANIGAWA  Seiya DEJIMA  Hideki TODE  

     
    PAPER

      Pubricized:
    2019/01/22
      Vol:
    E102-B No:7
      Page(s):
    1279-1291

    Recently, ZigBee has been attracting attention as a low-power and short-range wireless communication standard. In ZigBee networks, it is necessary to suppress frame transfer load because ZigBee needs to operate within severe capacity constraints and with low power consumption. However, in the typical environments in which ZigBee is used, such as smart home networks, WLAN (Wireless LAN) generally coexists, and radio interference occurs between the two networks. Existing studies focused on only interference avoidance. On the other hand, in this paper, we focus on adaptive cooperation between ZigBee network and WLAN. Specifically, from the viewpoints of WLANs that have wider communication range but have many idle periods in some environments like homes, we propose and study a hop count reduction method of ZigBee frame transfer by partially employing WLAN communication to transfer ZigBee frames. To the best of our knowledge, this is the first paper that considers the adaptive cooperation between ZigBee network and WLAN, where some ZigBee frames are transferred via WLAN to the sink. This is a completely new approach different from existing interference avoidance approaches. Then, we evaluate the hop count reduction by considering the number and the positions of relay points to transfer ZigBee frames to WLAN, and ZigBee tree topology for frame transfer routes. Through the evaluation, two realistic deployment policies of the relay points are derived. Finally, as specific advantages from the hop count reduction, we demonstrate the performance improvement about sink arrival ratio and end-to-end transfer delay of ZigBee frames, and energy consumption.

  • 12- and 21-GHz Dual-Band Dual-Circularly Polarized Offset Parabolic Reflector Antenna Fed by Microstrip Antenna Arrays for Satellite Broadcasting Reception Open Access

    Masafumi NAGASAKA  Masaaki KOJIMA  Hisashi SUJIKAI  Jiro HIROKAWA  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2019/01/09
      Vol:
    E102-B No:7
      Page(s):
    1323-1333

    In December 2018, satellite broadcasting for 4K/8K ultra-high-definition television (UHDTV) will begin in Japan. It will be provided in the 12-GHz (11.7 to 12.75GHz) band with right- and left-hand circular polarizations. BSAT-4a, a satellite used for broadcasting UHDTV, was successfully launched in September 2017. This satellite has not only 12-GHz-band right- and left-hand circular polarization transponders but also a 21-GHz-band experimental transponder. The 21-GHz (21.4 to 22.0GHz) band has been allocated as the downlink for broadcasting satellite service in ITU-R Regions 1 (Europe, Africa) and 3 (Asia Pacific). To receive services provided over these two frequency bands and with dual-polarization, we implement and evaluated a dual-band and dual-circularly polarized parabolic reflector antenna fed by 12- and 21-GHz-band microstrip antenna arrays with a multilayer structure. The antenna is used to receive 12- and 21-GHz-band signals from in-orbit satellites. The measured and experimental results prove that the proposed antenna performs as a dual-polarized antenna in those two frequency bands and has sufficient performance to receive satellite broadcasts.

  • Several Bits Are Enough: Off-Grid Target Localization in WSNs Using Variational Bayesian EM Algorithm

    Yan GUO  Peng QIAN  Ning LI  

     
    LETTER-Digital Signal Processing

      Vol:
    E102-A No:7
      Page(s):
    926-929

    The compressive sensing has been applied to develop an effective framework for simultaneously localizing multiple targets in wireless sensor networks. Nevertheless, existing methods implicitly use analog measurements, which have infinite bit precision. In this letter, we focus on off-grid target localization using quantized measurements with only several bits. To address this, we propose a novel localization framework for jointly estimating target locations and dealing with quantization errors, based on the novel application of the variational Bayesian Expectation-Maximization methodology. Simulation results highlight its superior performance.

  • A 385×385μm2 0.165V 0.27nW Fully-Integrated Supply-Modulated OOK Transmitter in 65nm CMOS for Glasses-Free, Self-Powered, and Fuel-Cell-Embedded Continuous Glucose Monitoring Contact Lens Open Access

    Kenya HAYASHI  Shigeki ARATA  Ge XU  Shunya MURAKAMI  Cong Dang BUI  Atsuki KOBAYASHI  Kiichi NIITSU  

     
    BRIEF PAPER

      Vol:
    E102-C No:7
      Page(s):
    590-594

    This work presents the lowest power consumption sub-mm2 supply-modulated OOK transmitter for self-powering a continuous glucose monitoring (CGM) contact lens. By combining the transmitter with a glucose fuel cell that functions as both the power source and a sensing transducer, a self-powered CGM contact lens was developed. The 385×385μm2 test chip implemented in 65-nm standard CMOS technology operates at 270pW with a supply voltage of 0.165V. Self-powered operation of the transmitter using a 2×2mm2 solid-state glucose fuel cell was thus demonstrated.

521-540hit(5768hit)