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[Keyword] CTI(8214hit)

1801-1820hit(8214hit)

  • Eigen Domain Channel-Unaware Narrowband Interference Suppression for Time Synchronization

    Fengwei LIU  Hongzhi ZHAO  Ying LIU  Youxi TANG  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E99-B No:5
      Page(s):
    1151-1156

    In this paper, we propose a channel-unaware algorithm to suppress the narrowband interference (NBI) for the time synchronization, where multiple antennas are equipped at the receiver. Based on the fact that the characteristics of synchronization signal are different from those of NBI in both the time and spatial domain, the proposed algorithm suppresses the NBI by utilizing the multiple receive antennas in the eigen domain of NBI, where the eigen domain is obtained from the time domain statistical information of NBI. Because time synchronization involves incoherent detection, the proposed algorithm does not use the desired channel information, which is different from the eigen domain interference rejection combining (E-IRC). Simulation results show, compared with the traditional frequency domain NBI suppression technique, the proposed algorithm has about a 2 dB gain under the same probability of detection.

  • Adaptive Directional Lifting Structure of Three Dimensional Non-Separable Discrete Wavelet Transform for High Resolution Volumetric Data Compression

    Fairoza Amira BINTI HAMZAH  Taichi YOSHIDA  Masahiro IWAHASHI  Hitoshi KIYA  

     
    PAPER-Digital Signal Processing

      Vol:
    E99-A No:5
      Page(s):
    892-899

    As three dimensional (3D) discrete wavelet transform (DWT) is widely used for high resolution volumetric data compression, and to further improve the performance of lossless coding, the adaptive directional lifting (ADL) structure based on non-separable 3D DWT with a (5,3) filter is proposed in this paper. The proposed 3D DWT has less lifting steps and better prediction performance compared to the existing separable 3D DWT with fixed filter coefficients. It also has compatibility with the conventional DWT defined by the JPEG2000 international standard. The proposed method shows comparable and better results with the non-separable 3D DWT and separable 3D DWT and it is effective for lossless coding of high resolution volumetric data.

  • New Power Factor Correction Application for a Small Wind Power System

    Jun-Hua CHIANG  Bin-Da LIU  Shih-Ming CHEN  Hong-Tzer YANG  

     
    PAPER-Electronic Circuits

      Vol:
    E99-C No:5
      Page(s):
    581-589

    This study proposes the application and implementation of a new power factor correction (PFC) with a variable slope ramp for a small wind power system without any input voltage sensing circuits or external control components in the current shaping loop. The hardware description of the variable slope ramp simplifies the complexity of integrated circuit realization with low resolution analog-to-digital converters, and achieves a high power factor for multi and three-phase AC/DC converters such as wind power systems. Up to 1 kW small wind power system is tested to verify the performance of the proposed PFC control. The highest achieved power factor reaches 99.5%.

  • An Application of Laser Annealing Process in Low-Voltage Planar Power MOSFETs

    Yi CHEN  Tatsuya OKADA  Takashi NOGUCHI  

     
    BRIEF PAPER-Semiconductor Materials and Devices

      Vol:
    E99-C No:5
      Page(s):
    601-603

    An application of laser annealing process, which is used to form the shallow P-type Base junction for 20-V planar power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors) is proposed. We demonstrated that the fabricated devices integrated with laser annealing process have superior electrical characteristics than those fabricated according to the standard process. Moreover, the threshold voltage variation of the devices applied by the new annealing process is effectively suppressed. This is due to that a uniform impurity distribution at the channel region is achieved by adopting laser annealing. Laser annealing technology can be applied as a reliable, effective, and advantageous process for the low-voltage power MOSFETs.

  • Efficient Active Measurement for Monitoring Link-by-Link Performance in OpenFlow Networks

    Megumi SHIBUYA  Atsuo TACHIBANA  Teruyuki HASEGAWA  

     
    PAPER

      Vol:
    E99-B No:5
      Page(s):
    1032-1040

    To efficiently monitor the link performance in an OpenFlow network with a single measurement box (referred to a “beacon”), this paper presents a measurement scheme that calculates a set of measurement paths from the beacon to cover all links in the network based on the controllable feature of individual measurement paths in the OpenFlow network and comprehensively estimates the performance of all the physical links from round-trip active measurements. The scheme has a novel feature that minimize the maximum number of exclusive flow-entries for active measurements on OpenFlow switches by utilizing common packet header values in the probing packets to aggregate multiple entries into a single entry to save the resources in OpenFlow switches and controller. We demonstrate the effectiveness and feasibility of our solution through simulations and emulation scenarios.

  • Hierarchical-IMM Based Maneuvering Target Tracking in LOS/NLOS Hybrid Environments

    Yan ZHOU  Lan HU  Dongli WANG  

     
    PAPER-Systems and Control

      Vol:
    E99-A No:5
      Page(s):
    900-907

    Maneuvering target tracking under mixed line-of-sight/non-line-of-sight (LOS/NLOS) conditions has received considerable interest in the last decades. In this paper, a hierarchical interacting multiple model (HIMM) method is proposed for estimating target position under mixed LOS/NLOS conditions. The proposed HIMM is composed of two layers with Markov switching model. The purpose of the upper layer, which is composed of two interacting multiple model (IMM) filters in parallel, is to handle the switching between the LOS and the NLOS environments. To estimate the target kinetic variables (position, speed and acceleration), the unscented Kalman filter (UKF) with the current statistical (CS) model is used in the lower-layer. Simulation results demonstrate the effectiveness and superiority of the proposed method, which obtains better tracking accuracy than the traditional IMM.

  • Layout-Conscious Expandable Topology for Low-Degree Interconnection Networks

    Thao-Nguyen TRUONG  Khanh-Van NGUYEN  Ikki FUJIWARA  Michihiro KOIBUCHI  

     
    PAPER-Computer System

      Pubricized:
    2016/02/02
      Vol:
    E99-D No:5
      Page(s):
    1275-1284

    System expandability becomes a major concern for highly parallel computers and data centers, because their number of nodes gradually increases year by year. In this context we propose a low-degree topology and its floor layout in which a cabinet or node set can be newly inserted by connecting short cables to a single existing cabinet. Our graph analysis shows that the proposed topology has low diameter, low average shortest path length and short average cable length comparable to existing topologies with the same degree. When incrementally adding nodes and cabinets to the proposed topology, its diameter and average shortest path length increase modestly. Our discrete-event simulation results show that the proposed topology provides a comparable performance to 2-D Torus for some parallel applications. The network cost and power consumption of DSN-F modestly increase when compared to the counterpart non-random topologies.

  • Investigation of Electron Irradiation Effects on Graphene by Optical and Electrical Characterization

    Hiroshi OKADA  Akira NAGAHARA  

     
    BRIEF PAPER

      Vol:
    E99-C No:5
      Page(s):
    559-562

    Effects of electron beam irradiation at 15 keV on graphene are investigated by optical and electron characterization using Raman and two-terminal resistance measurement and photoconductivity measurement. In Raman spectra, increase of defects in D-peak to G-peak ratio by increase of electron irradiation by 70 mC/cm2 was found. Resistance of graphene showed an increase after the irradiation. Rather sensitive change was found in photoconductivity of irradiated graphene under ultra-violet (UV) illumination, suggesting irradiation induced defects affect a photoconductivity properties of the graphene.

  • An Application of Laser Annealing Process in Low-Voltage Power MOSFETs

    Yi CHEN  Tatsuya OKADA  Takashi NOGUCHI  

     
    PAPER

      Vol:
    E99-C No:5
      Page(s):
    516-521

    An application of laser annealing process, which is used to form the P-type Base junction for high-performance low-voltage power MOSFETs (Metal Oxide Semiconductor Field Effect Transistors), is proposed. An equivalent shallow-junction structure for P-Base junction with uniform impurity distribution is achieved by adopting green laser annealing of pulsed mode. Higher impurity activation for the shallow junction has been achieved by the laser annealing of melted phase than by conventional RTA (Rapid Thermal Annealing) of solid phase. The application of the laser annealing technology in the fabrication process of Low-Voltage U-MOSFET is also examined.

  • Accelerating Multi-Label Feature Selection Based on Low-Rank Approximation

    Hyunki LIM  Jaesung LEE  Dae-Won KIM  

     
    LETTER-Pattern Recognition

      Pubricized:
    2016/02/12
      Vol:
    E99-D No:5
      Page(s):
    1396-1399

    We propose a multi-label feature selection method that considers feature dependencies. The proposed method circumvents the prohibitive computations by using a low-rank approximation method. The empirical results acquired by applying the proposed method to several multi-label datasets demonstrate that its performance is comparable to those of recent multi-label feature selection methods and that it reduces the computation time.

  • Low PAPR Signal Design for CIOD Using Selected and Clipped QAM Signal

    Ho Kyoung LEE  Changjoong KIM  Seo Weon HEO  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E99-B No:5
      Page(s):
    1143-1150

    Coordinate interleaved orthogonal design (CIOD) using four transmit antennas provides full diversity, full rate (FDFR) properties with low decoding complexity. However, the constellation expansion due to the coordinate interleaving of the rotated constellation results in peak to average power ratio (PAPR) increase. In this paper, we propose two signal constellation design methods which have low PAPR. In the first method we propose a signal constellation by properly selecting the signal points among the expanded square QAM constellation points, based on the co-prime interleaving of the first coordinate signal. We design a regular interleaving pattern so that the coordinate distance product (CPD) after the interleaving becomes large to get the additional coding gain. In the other method we propose a novel constellation with low PAPR based on the clipping of the rotated square QAM constellation. Our proposed signal constellations show much lower PAPR than the ordinary rotated QAM constellations for CIOD.

  • Performance Analysis of Two-Way Relaying Network with Adaptive Modulation in the Presence of Imperfect Channel Information

    Kyu-Sung HWANG  MinChul JU  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E99-B No:5
      Page(s):
    1170-1179

    In this paper, we study the impact of imperfect channel information on an amplify-and-forward (AF)-based two-way relaying network (TWRN) with adaptive modulation which consists of two end-terminals and multiple relays. Specifically, we consider a single-relay selection scheme of the TWRN in the presence of outdated channel state information (CSI) and channel estimation errors. First, we choose the best relay based on outdated CSI, and perform adaptive modulation on both relaying paths with channel estimation errors. Then, we discuss the impact of the outdated CSI on the statistics of the signal-to-noise ratio (SNR) per hop. In addition, we formulate the end-to-end SNRs with channel estimation errors and offer statistic analyses in the presence of both the outdated CSI and channel estimation errors. Finally, we provide the performance analyses of the proposed TWRN with adaptive modulation in terms of average spectral efficiency, average bit error rate, and outage probability. Numerical examples are given to verify our obtained analytical results for various system conditions.

  • Information-Theoretic Performance Evaluation of Multibiometric Fusion under Modality Selection Attacks

    Takao MURAKAMI  Yosuke KAGA  Kenta TAKAHASHI  

     
    PAPER-Cryptography and Information Security

      Vol:
    E99-A No:5
      Page(s):
    929-942

    The likelihood-ratio based score level fusion (LR-based fusion) scheme has attracted much attention, since it maximizes accuracy if a log-likelihood ratio (LLR) is accurately estimated. In reality, it can happen that a user cannot input some query samples due to temporary physical conditions such as injuries and illness. It can also happen that some modalities tend to cause false rejection (i.e. the user is a “goat” for these modalities). The LR-based fusion scheme can handle these situations by setting LLRs corresponding to missing query samples to 0. In this paper, we refer to such a mode as a “modality selection mode”, and address an issue of accuracy in this mode. Specifically, we provide the following contributions: (1) We firstly propose a “modality selection attack”, in which an impostor inputs only query samples whose LLRs are more than 0 (i.e. takes an optimal strategy) to impersonate others. We also show that the impostor can perform this attack against the SPRT (Sequential Probability Ratio Test)-based fusion scheme, which is an extension of the LR-based fusion scheme to a sequential fusion scenario. (2) We secondly consider the case when both genuine users and impostors take this optimal strategy, and show that the overall accuracy in this case is “worse” than the case when they input all query samples. More specifically, we prove that the KL (Kullback-Leibler) divergence between a genuine distribution of integrated scores and an impostor's one, which can be compared with password entropy, is smaller in the former case. We also show to what extent the KL divergence losses for each modality. (3) We finally evaluate to what extent the overall accuracy becomes worse using the NIST BSSR1 Set 2 and Set 3 datasets, and discuss directions of multibiometric applications based on the experimental results.

  • Low-Temperature Activation in Boron Ion-Implanted Silicon by Soft X-Ray Irradiation

    Akira HEYA  Naoto MATSUO  Kazuhiro KANDA  

     
    PAPER-Semiconductor Materials and Devices

      Vol:
    E99-C No:4
      Page(s):
    474-480

    A novel activation method for a B dopant implanted in a Si substrate using a soft X-ray undulator was examined. As the photon energy of the irradiated soft X-ray approached the energy of the core level of Si 2p, the activation ratio increased. The effect of soft X-ray irradiation on B activation was remarkable at temperatures lower than 400°C. The activation energy of B activation by soft X-ray irradiation (0.06 eV) was lower than that of B activation by furnace annealing (0.18 eV). The activation of the B dopant by soft X-ray irradiation occurs at low temperature, although the activation ratio shows small values of 6.2×10-3 at 110°C. The activation by soft X-ray is caused not only by thermal effects, but also electron excitation and atomic movement.

  • A 12.5Gbps CDR with Differential to Common Converting Edge Detector for the Wired and Wireless Serial Link

    Kaoru KOHIRA  Hiroki ISHIKURO  

     
    PAPER-Electronic Circuits

      Vol:
    E99-C No:4
      Page(s):
    458-465

    This paper introduces low-power and small area injection-locking clock and data recovery circuit (CDR) for the wireline and wireless proximity link. By using signal conversion from differential input to common-mode output, the newly proposed edge detector can eliminate the usually used delay line and XOR-based edge detector, and provided low power operation and a small circuit area. The CDR test chip fabricated in a 65-nm CMOS process consumes 30mW from a 1.2- V supply at 12.5Gbps. The fabricated CDR achieved a BER lower than 10-12 and the recovered clock had an rms jitter of 0.87ps. The CDR area is 0.165mm2.

  • Fast Mode Decision Technique for HEVC Intra Prediction Based on Reliability Metric for Motion Vectors

    Chihiro TSUTAKE  Yutaka NAKANO  Toshiyuki YOSHIDA  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2016/01/21
      Vol:
    E99-D No:4
      Page(s):
    1193-1201

    This paper proposes a fast mode decision technique for intra prediction of High Efficiency Video Coding (HEVC) based on a reliability metric for motion vectors (RMMV). Since such a decision problem can be regarded as a kind of pattern classification, an efficient classifier is required for the reduction of computation complexity. This paper employs the RMMV as a classifier because the RMMV can efficiently categorize image blocks into flat(uniform), active, and edge blocks, and can estimate the direction of an edge block as well. A local search for angular modes is introduced to further speed up the decision process. An experiment shows the advantage of our technique over other techniques.

  • A Partitioning Parallelization with Hybrid Migration of MOEA/D for Bi-Objective Optimization on Message-Passing Clusters

    Yu WU  Yuehong XIE  Weiqin YING  Xing XU  Zixing LIU  

     
    LETTER-Numerical Analysis and Optimization

      Vol:
    E99-A No:4
      Page(s):
    843-848

    A partitioning parallelization of the multi-objective evolutionary algorithm based on decomposition, pMOEA/D, is proposed in this letter to achieve significant time reductions for expensive bi-objective optimization problems (BOPs) on message-passing clusters. Each sub-population of pMOEA/D resides on a separate processor in a cluster and consists of a non-overlapping partition and some extra overlapping individuals for updating neighbors. Additionally, sub-populations cooperate across separate processors by the hybrid migration of elitist individuals and utopian points. Experimental results on two benchmark BOPs and the wireless sensor network layout problem indicate that pMOEA/D achieves satisfactory performance in terms of speedup and quality of solutions on message-passing clusters.

  • Automatic Recognition of Mycobacterium Tuberculosis Based on Active Shape Model

    Chao XU  Dongxiang ZHOU  Tao GUAN  Yongping ZHAI  Yunhui LIU  

     
    PAPER-Pattern Recognition

      Pubricized:
    2016/01/08
      Vol:
    E99-D No:4
      Page(s):
    1162-1171

    This paper realized the automatic recognition of Mycobacterium tuberculosis in Ziehl-Neelsen stained images by the conventional light microscopy, which can be used in the computer-aided diagnosis of the tuberculosis. We proposed a novel recognition method based on active shape model. First, the candidate bacillus objects are segmented by a method of marker-based watershed transform. Next, a point distribution model of the object shape is proposed to label the landmarks on the object automatically. Then the active shape model is performed after aligning the training set with a weight matrix. The deformation regulation of the object shape is discovered and successfully applied in recognition without using geometric and other commonly used features. During this process, a width consistency constraint is combined with the shape parameter to improve the accuracy of the recognition. Experimental results demonstrate that the proposed method yields high accuracy in the images with different background colors. The recognition accuracy in object level and image level are 92.37% and 97.91% respectively.

  • Automatic Erroneous Data Detection over Type-Annotated Linked Data

    Md-Mizanur RAHOMAN  Ryutaro ICHISE  

     
    PAPER

      Pubricized:
    2016/01/14
      Vol:
    E99-D No:4
      Page(s):
    969-978

    These days, the Web contains a huge volume of (semi-)structured data, called Linked Data (LD). However, LD suffer in data quality, and this poor data quality brings the need to identify erroneous data. Because manual erroneous data checking is impractical, automatic erroneous data detection is necessary. According to the data publishing guidelines of LD, data should use (already defined) ontology which populates type-annotated LD. Usually, the data type annotation helps in understanding the data. However, in our observation, the data type annotation could be used to identify erroneous data. Therefore, to automatically identify possible erroneous data over the type-annotated LD, we propose a framework that uses a novel nearest-neighbor based error detection technique. We conduct experiments of our framework on DBpedia, a type-annotated LD dataset, and found that our framework shows better performance of error detection in comparison with state-of-the-art framework.

  • Variation of SCM/NAND Flash Hybrid SSD Performance, Reliability and Cost by Using Different SSD Configurations and Error Correction Strengths

    Hirofumi TAKISHITA  Shuhei TANAKAMARU  Sheyang NING  Ken TAKEUCHI  

     
    PAPER

      Vol:
    E99-C No:4
      Page(s):
    444-451

    Storage-Class Memory (SCM) and NAND flash hybrid Solid-State Drive (SSD) has advantages of high performance and low power consumption compared with NAND flash only SSD. In this paper, first, three SSD configurations are investigated. Three different SCMs are used with 0.1 µs, 1 µs and 10 µs read/write latencies, respectively, and the required SCM/NAND flash capacity ratios are analyzed to maintain the same SSD performance. Next, by using the three SSD configurations, the variation of SSD reliability, performance and cost are analyzed by changing error correction strengths. The SSD reliability of acceptable SCM and NAND flash Bit Error Rates (BERs) is limited by achieving specified SSD performance with error correction, and/or limited by SCM and NAND flash parity size and SSD cost. Lastly, the SSD replacement cost is also analyzed by considering the limitation of NAND flash write/erase cycles. The purpose of this paper is to provide a design guideline for obtaining high performance, highly reliable and cost-effective SCM/NAND hybrid structure SSD with ECC.

1801-1820hit(8214hit)