The search functionality is under construction.
The search functionality is under construction.

Keyword Search Result

[Keyword] (42807hit)

8221-8240hit(42807hit)

  • Delay-Insertion-Based P2PTV Traffic Localization Using AS-Level Topology Information

    Chitapong WECHTAISONG  Kazato IKEDA  Hiroaki MORINO  Takumi MIYOSHI  

     
    PAPER-Network

      Vol:
    E98-B No:11
      Page(s):
    2259-2268

    Most P2PTV systems select a neighbor peer in an overlay network using RTT or a random method without considering the underlying network. Streaming traffic is shared over a network without localization awareness, which is a serious problem for Internet Service Providers. In this paper, we present a novel scheme to achieve P2PTV traffic localization by inserting delay into P2P streaming packets, so that the length of the inserted delay depends on the AS hop distance between a peer and its neighbor peer. Experiments conducted on a real network show that our proposed scheme can perform efficient traffic localization.

  • Fast Repairing from Large-Scale Failure Using Hierarchical SDN Controllers

    Shohei KAMAMURA  Hiroshi YAMAMOTO  Kouichi GENDA  Yuki KOIZUMI  Shin'ichi ARAKAWA  Masayuki MURATA  

     
    PAPER-Network

      Vol:
    E98-B No:11
      Page(s):
    2269-2279

    This paper proposes fast repairing methods that uses hierarchical software defined network controllers for recovering from massive failure in a large-scale IP over a wavelength-division multiplexing network. The network consists of multiple domains, and slave controllers are deployed in each domain. While each slave controller configures transport paths in its domain, the master controller manages end-to-end paths, which are established across multiple domains. For fast repair of intra-domain paths by the slave controllers, we define the optimization problem of path configuration order and propose a heuristic method, which minimizes the repair time to move from a disrupted state to a suboptimal state. For fast repair of end-to-end path through multiple domains, we also propose a network abstraction method, which efficiently manages the entire network. Evaluation results suggest that fast repair within a few minutes can be achieved by applying the proposed methods to the repairing scenario, where multiple links and nodes fail, in a 10,000-node network.

  • Real-Valued Reweighted l1 Norm Minimization Method Based on Data Reconstruction in MIMO Radar

    Qi LIU  Wei WANG  Dong LIANG  Xianpeng WANG  

     
    PAPER-Antennas and Propagation

      Vol:
    E98-B No:11
      Page(s):
    2307-2313

    In this paper, a real-valued reweighted l1 norm minimization method based on data reconstruction in monostatic multiple-input multiple-output (MIMO) radar is proposed. Exploiting the special structure of the received data, and through the received data reconstruction approach and unitary transformation technique, a one-dimensional real-valued received data matrix can be obtained for recovering the sparse signal. Then a weight matrix based on real-valued MUSIC spectrum is designed for reweighting l1 norm minimization to enhance the sparsity of solution. Finally, the DOA can be estimated by finding the non-zero rows in the recovered matrix. Compared with traditional l1 norm-based minimization methods, the proposed method provides better angle estimation performance. Simulation results are presented to verify the effectiveness and advantage of the proposed method.

  • Transparent Organic Light-Emitting Diodes with Top Electrode Using Ion-Plating Method

    Hironao SANO  Ryota ISHIDA  Tatsuya KURA  Shunsuke FUJITA  Shigeki NAKA  Hiroyuki OKADA  Takeshi TAKAI  

     
    BRIEF PAPER

      Vol:
    E98-C No:11
      Page(s):
    1035-1038

    Transparent organic light-emitting diodes (TOLEDs) were investigated with top electrode of indium-tin-oxide (ITO) by ion-plating method. High deposition rate of 4.4 nm/s was realized without plasma damage of under organic layer. In the TOLEDs with inverted structure, high transmittance of over 75% at 550 nm and bright emission of 1,850 and 1,410 cd/m2, from bottom and top side at 163 mA/cm2, respectively, were obtained.

  • A New Connected-Component Labeling Algorithm

    Xiao ZHAO  Lifeng HE  Bin YAO  Yuyan CHAO  

     
    LETTER-Pattern Recognition

      Pubricized:
    2015/08/05
      Vol:
    E98-D No:11
      Page(s):
    2013-2016

    This paper presents a new connected component labeling algorithm. The proposed algorithm scans image lines every three lines and processes pixels three by three. When processing the current three pixels, we also utilize the information obtained before to reduce the repeated work for checking pixels in the mask. Experimental results demonstrated that our method is more efficient than the fastest conventional labeling algorithm.

  • Penalized AdaBoost: Improving the Generalization Error of Gentle AdaBoost through a Margin Distribution

    Shuqiong WU  Hiroshi NAGAHASHI  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2015/08/13
      Vol:
    E98-D No:11
      Page(s):
    1906-1915

    Gentle AdaBoost is widely used in object detection and pattern recognition due to its efficiency and stability. To focus on instances with small margins, Gentle AdaBoost assigns larger weights to these instances during the training. However, misclassification of small-margin instances can still occur, which will cause the weights of these instances to become larger and larger. Eventually, several large-weight instances might dominate the whole data distribution, encouraging Gentle AdaBoost to choose weak hypotheses that fit only these instances in the late training phase. This phenomenon, known as “classifier distortion”, degrades the generalization error and can easily lead to overfitting since the deviation of all selected weak hypotheses is increased by the late-selected ones. To solve this problem, we propose a new variant which we call “Penalized AdaBoost”. In each iteration, our approach not only penalizes the misclassification of instances with small margins but also restrains the weight increase for instances with minimal margins. Our method performs better than Gentle AdaBoost because it avoids the “classifier distortion” effectively. Experiments show that our method achieves far lower generalization errors and a similar training speed compared with Gentle AdaBoost.

  • Active Noise Canceling for Headphones Using a Hybrid Structure with Wind Detection and Flexible Independent Component Analysis

    Dong-Hyun LIM  Minook KIM  Hyung-Min PARK  

     
    LETTER-Music Information Processing

      Pubricized:
    2015/07/31
      Vol:
    E98-D No:11
      Page(s):
    2043-2046

    This letter presents a method for active noise cancelation (ANC) for headphone application. The method improves the performance of ANC by deriving a flexible independent component analysis (ICA) algorithm in a hybrid structure combining feedforward and feedback configurations with correlation-based wind detection. The effectiveness of the method is demonstrated through simulation.

  • Multi-Phase Convex Lens Array for Directional Backlights to Improve Luminance Distribution of Autostereoscopic Display Open Access

    Shuta ISHIZUKA  Takuya MUKAI  Hideki KAKEYA  

     
    INVITED PAPER

      Vol:
    E98-C No:11
      Page(s):
    1023-1027

    We realize homogenous luminance of the directional backlight for the time-division multiplexing autostereoscopic display using a convex lens array with the elemental lenses whose phase of placement in each row differs from one another. The validity of the proposed optical design is confirmed by a prototype system.

  • Facilitating Incentive-Compatible Access Probability Selection in Wireless Random Access Networks

    Bo GU  Cheng ZHANG  Kyoko YAMORI  Zhenyu ZHOU  Song LIU  Yoshiaki TANAKA  

     
    PAPER-Network

      Vol:
    E98-B No:11
      Page(s):
    2280-2290

    This paper studies the impact of integrating pricing with connection admission control (CAC) on the congestion management practices in contention-based wireless random access networks. Notably, when the network is free of charge, each self-interested user tries to occupy the channel as much as possible, resulting in the inefficient utilization of network resources. Pricing is therefore adopted as incentive mechanism to encourage users to choose their access probabilities considering the real-time network congestion level. A Stackelberg leader-follower game is formulated to analyze the competitive interaction between the service provider and the users. In particular, each user chooses the access probability that optimizes its payoff, while the self-interested service provider decides whether to admit or to reject the user's connection request in order to optimize its revenue. The stability of the Stackelberg leader-follower game in terms of convergence to the Nash equilibrium is established. The proposed CAC scheme is completely distributed and can be implemented by individual access points using only local information. Compared to the existing schemes, the proposed scheme achieves higher revenue gain, higher user payoff, and higher QoS performance.

  • Highly Compressed Lists of Integers with Dense Padding Modes

    Kun JIANG  Xingshen SONG  Yuexiang YANG  

     
    LETTER-Data Engineering, Web Information Systems

      Pubricized:
    2015/08/19
      Vol:
    E98-D No:11
      Page(s):
    1986-1989

    Index compression is partially responsible for the current performance achievements of Internet search engines. Among many latest compression techniques, Simple9 can pack as many integers as possible into a single 32-bit machine word using 9 different padding modes. However, the number of wasted bits in Simple9 remains large. In previous works, researchers have focused on reducing the unused trailing bits of the padding modes and have proposed various additional modes that make full use of the cases of the status bits. Instead, we focus on the wasted bits in the integer list, padding extra zeros for a complete dense mode when the number of integers is not enough to fit a complete mode. More precisely, we first propose a novel index compression method called SimpleD with dense padding modes to achieve a more compact storage compared with that of Simple9. We then design an innovative metric for extracting the inserted extra zero integers during the decoding phase. Experiments on the TREC WT2G and GOV2 datasets show that our encoder outperforms Simple9 while still retaining a very fast decompression speed.

  • Al-Based Metal Mesh Electrodes for Advanced Touch Screen Panels Using Aluminum Nitride System Optical Absorption Layer Open Access

    Mototaka OCHI  Yoko SHIDA  Hiroyuki OKUNO  Hiroshi GOTO  Toshihiro KUGIMIYA  Moriyoshi KANAMARU  

     
    INVITED PAPER

      Vol:
    E98-C No:11
      Page(s):
    1000-1007

    An Al-N system optical absorption layer has been developed, to be used for Al-based metal mesh electrodes on touch screen panels. The triple-layered electrode effectively suppresses the optical reflection in both visible light and the blue color region and exhibits excellent wet etching property that accommodates micro-fabrication. Due to its high noise immunity and contact sensitivity originating from its low electrical resistivity, the proposed metal mesh electrodes are useful for touch-sensitive panels in the next generation ultra-high-resolution displays.

  • Capacitance Sensor of Frequency Modulation for Integrated Touchpanels Using Amorphous In-Sn-Zn-O Thin-Film Transistors

    Yuki KOGA  Tokiyoshi MATSUDA  Mutsumi KIMURA  Dapeng WANG  Mamoru FURUTA  Masashi KASAMI  Shigekazu TOMAI  Koki YANO  

     
    BRIEF PAPER

      Vol:
    E98-C No:11
      Page(s):
    1028-1031

    We have developed a capacitance sensor of frequency modulation for integrated touchpanels using amorphous In-Sn-Zn-O (α-ITZO) thin-film transistors (TFTs). This capacitance sensor consists of a ring oscillator, whose one stage is replaced by a reset transistor, sensing transistor, and sensing electrode. The sensing electrode is prepared as one terminal to form a sensing capacitor when the other terminal is added by a finger. The ring oscillator consists of pseudo CMOS inverters. We confirm that the oscillation frequency changes when the other terminal is added. This result suggests that this capacitance sensor can be applied to integrated touchpanels on flatpanel displays.

  • Flexible In-Plane-Switching Liquid Crystal Display Using Stretched Polycarbonate Substrates with Optical Positive A-Plate

    Akihito SATO  Takahiro ISHINABE  Hideo FUJIKAKE  

     
    BRIEF PAPER

      Vol:
    E98-C No:11
      Page(s):
    1039-1042

    Optical compensation of flexible in-plane switching (IPS) mode liquid crystal display (LCD) using polycarbonate substrate with uniaxial optical anisotropy was achieved for wide viewing angle. We theoretically clarified that the slow axis of plastic substrate must be parallel to the absorption axis of polarizer and alignment direction of IPS mode LC. We successfully suppressed a light leakage in the dark state in a wide viewing angle range by fabricated device using uniaxial polycarbonate substrates. These results show that it is possible to realize a high quality flexible LCD using plastic substrates.

  • Efficient Anchor Graph Hashing with Data-Dependent Anchor Selection

    Hiroaki TAKEBE  Yusuke UEHARA  Seiichi UCHIDA  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2015/08/17
      Vol:
    E98-D No:11
      Page(s):
    2030-2033

    Anchor graph hashing (AGH) is a promising hashing method for nearest neighbor (NN) search. AGH realizes efficient search by generating and utilizing a small number of points that are called anchors. In this paper, we propose a method for improving AGH, which considers data distribution in a similarity space and selects suitable anchors by performing principal component analysis (PCA) in the similarity space.

  • A Low-Complexity PTS Scheme with the Hybrid Subblock Partition Method for PAPR Reduction in OFDM Systems

    Sheng-Ju KU  Yuan OUYANG  Chiachi HUANG  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E98-B No:11
      Page(s):
    2341-2347

    The technique of partial transmit sequences (PTS) is effective in reducing the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals. However, the conventional PTS (CPTS) scheme has high computation complexity because it needs several inverse fast Fourier transform (IFFT) units and an optimization process to find the candidate signal with the lowest PAPR. In this paper, we propose a new low-complexity PTS scheme for OFDM systems, in which a hybrid subblock partition method (SPM) is used to reduce the complexity that results from the IFFT computations and the optimization process. Also, the PAPR reduction performance of the proposed PTS scheme is further enhanced by multiplying a selected subblock with a predefined phase rotation vector to form a new subblock. The time-domain signal of the new subblock can be obtained simply by performing a circularly-shift-left operation on the IFFT output of the selected subblock. Computer simulations show that the proposed PTS scheme achieves a PAPR reduction performance close to that of the CPTS scheme with the pseudo-random SPM, but with much lower computation complexity.

  • Electrostatic Tactile Display Using Beat Phenomenon for Stimulus Localization Open Access

    Hiroshi HAGA  Kazuhide YOSHINAGA  Jiro YANASE  Daisuke SUGIMOTO  Kenichi TAKATORI  Hideki ASADA  

     
    INVITED PAPER

      Vol:
    E98-C No:11
      Page(s):
    1008-1014

    We present an electrostatic tactile display for stimulus localization. The 240-Hz electrostatic force was generated by the beat phenomenon in a region where excited X electrodes cross excited Y electrodes, which presents localized tactile sensation out of the entire surface. A 10.4-in. visual-tactile integrated display was successfully demonstrated.

  • Training Assist System of a Lower Limb Prosthetic Visualizing Floor-Reaction Forces Using a Color-Depth Sensing Camera

    Kunihiro OGATA  Tomoki MITA  Takeshi SHIMIZU  Nobuya YAMASAKI  

     
    PAPER-Rehabilitation Engineering and Assistive Technology

      Pubricized:
    2015/07/28
      Vol:
    E98-D No:11
      Page(s):
    1916-1922

    Some unilateral lower-limb amputees, have through continued exertion, increase the foot reaction force of the sound leg. The asymmetric gait with a prosthetic leg may thus negatively affect the musculoskeletal health of the leg on the healthy side. Therefore, it is important for these amputees to learn how to adjust the balance of each foot load in training. The aim of this study is to develop a training support system visualizing floor-reaction forces using a color-depth sensor. The pose of the entire body of the amputee is measured by the depth sensor, and the floor reaction force is estimated based on Zero Moment Point (ZMP), which is calculated using the center of mass of the amputee. Evaluation experiments of the proposed method were performed and they confirmed the effectiveness of the estimation method and the training with the visualization of reaction force.

  • A DUET-Based Method for Blind Separation of Speech Signals in Reverberant Environments

    Minook KIM  Tae-Jun LEE  Hyung-Min PARK  

     
    LETTER-Speech and Hearing

      Vol:
    E98-A No:11
      Page(s):
    2325-2329

    This letter presents a two-stage method to extend the degenerate unmixing estimation technique (DUET) for reverberant speech separation. First, frequency-bin-wise attenuation and delay parameters are introduced and estimated by online update rules, to handle early reflections. Next, a mask reestimation algorithm based on the precedence effect is developed to detect and fix the errors on binary masks caused by late reflections. Experimental results demonstrate that the proposed method improves separation performance significantly.

  • Achievement Accurate CSI for AF Relay MIMO/OFDM Based on Complex HTRCI Pilot Signal with Enhanced MMSE Equalization

    Yuta IDA  Chang-Jun AHN  Takahiro MATSUMOTO  Shinya MATSUFUJI  

     
    PAPER

      Vol:
    E98-A No:11
      Page(s):
    2254-2262

    Amplify-and-forward (AF) relay multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems can achieve high data rate and high quality communications. On the other hand, it has to estimate all channels between the source-relay and relay-destination nodes in the destination node. In MIMO/OFDM systems, high time resolution carrier interferometry (HTRCI) has been proposed to achieve an accurate channel estimation (CE) with a small number of pilot signals. However, since it has many interferences, an accurate CE is not obtained and the system performance is degraded in AF relay MIMO/OFDM systems. Therefore, in this paper, we propose the complex HTRCI (C-HTRCI) pilot signal and the enhanced minimum mean square error (E-MMSE) equalization to achieve an accurate CE and to improve the system performance for AF relay MIMO/OFDM systems.

  • Multi-Rate Representation of Generalized Cyclotomic Sequences of Any Odd Period

    Chuan LV  Tongjiang YAN  Guozhen XIAO  

     
    PAPER-Cryptography and Information Security

      Vol:
    E98-A No:11
      Page(s):
    2301-2306

    Based on a unified representation of generalized cyclotomic classes, every generalized cyclotomic sequence of order d over $Z_{p_{1}^{e_{1}}p_{2}^{e_{2}}cdots p_{r}^{e_{r}}}$ is shown to be a sum of d-residue sequences over $Z_{p_{s}^{e_{s}}}$ for $sin {1,2,cdots,r }$. For d=2, by the multi-rate approach, several generalized cyclotomic sequences are explicitly expressed by Legendre sequences, and their linear complexity properties are analyzed.

8221-8240hit(42807hit)