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641-660hit(5900hit)

  • An Improved Closed-Form Method for Moving Source Localization Using TDOA, FDOA, Differential Doppler Rate Measurements

    Zhixin LIU  Dexiu HU  Yongsheng ZHAO  Yongjun ZHAO  

     
    PAPER-Sensing

      Pubricized:
    2018/12/03
      Vol:
    E102-B No:6
      Page(s):
    1219-1228

    This paper proposes an improved closed-form method for moving source localization using time difference of arrival (TDOA), frequency difference of arrival (FDOA) and differential Doppler rate measurements. After linearizing the measurement equations by introducing three additional parameters, a rough estimate is obtained by using the weighted least-square (WLS) estimator. To further refine the estimate, the relationship between additional parameters and source location is utilized. The proposed method gives a final closed-form solution without iteration or the extra mathematics operations used in existing methods by employing the basic idea of WLS processing. Numerical examples show that the proposed method exhibits better robustness and performance compared with several existing methods.

  • Topological Consistency-Based Virtual Network Embedding in Elastic Optical Networks

    Wenting WEI  Kun WANG  Gu BAN  Keming FENG  Xuan WANG  Huaxi GU  

     
    LETTER-Information Network

      Pubricized:
    2019/03/01
      Vol:
    E102-D No:6
      Page(s):
    1206-1209

    Network virtualization is viewed as a promising approach to facilitate the sharing of physical infrastructure among different kinds of users and applications. In this letter, we propose a topological consistency-based virtual network embedding (TC-VNE) over elastic optical networks (EONs). Based on the concept of topological consistency, we propose a new node ranking approach, named Sum-N-Rank, which contributes to the reduction of optical path length between preferred substrate nodes. In the simulation results, we found our work contributes to improve spectral efficiency and balance link load simultaneously without deteriorating blocking probability.

  • Prevention of Highly Power-Efficient Circuits due to Short-Channel Effects in MOSFETs

    Arnab MUKHOPADHYAY  Tapas Kumar MAITI  Sandip BHATTACHARYA  Takahiro IIZUKA  Hideyuki KIKUCHIHARA  Mitiko MIURA-MATTAUSCH  Hafizur RAHAMAN  Sadayuki YOSHITOMI  Dondee NAVARRO  Hans Jürgen MATTAUSCH  

     
    PAPER-Semiconductor Materials and Devices

      Vol:
    E102-C No:6
      Page(s):
    487-494

    This report focuses on an optimization scheme of advanced MOSFETs for designing CMOS circuits with high power efficiency. For this purpose the physics-based compact model HiSIM2 is applied so that the relationship between device and circuit characteristics can be investigated properly. It is demonstrated that the short-channel effect, which is usually measured by the threshold-voltage shift relative to long-channel MOSFETs, provides a consistent measure for device-performance degradation with reduced channel length. However, performance degradations of CMOS circuits such as the power loss cannot be predicted by the threshold-voltage shift alone. Here, the subthreshold swing is identified as an additional important measure for power-efficient CMOS circuit design. The increase of the subthreshold swing is verified to become obvious when the threshold-voltage shift is larger than 0.15V.

  • An Architecture for Real-Time Retinex-Based Image Enhancement and Haze Removal and Its FPGA Implementation Open Access

    Dabwitso KASAUKA  Kenta SUGIYAMA  Hiroshi TSUTSUI  Hiroyuki OKUHATA  Yoshikazu MIYANAGA  

     
    PAPER

      Vol:
    E102-A No:6
      Page(s):
    775-782

    In recent years, much research interest has developed in image enhancement and haze removal techniques. With increasing demand for real time enhancement and haze removal, the need for efficient architecture incorporating both haze removal and enhancement is necessary. In this paper, we propose an architecture supporting both real-time Retinex-based image enhancement and haze removal, using a single module. Efficiently leveraging the similarity between Retinex-based image enhancement and haze removal algorithms, we have successfully proposed an architecture supporting both using a single module. The implementation results reveal that just 1% logic circuits overhead is required to support Retinex-based image enhancement in single mode and haze removal based on Retinex model. This reduction in computation complexity by using a single module reduces the processing and memory implications especially in mobile consumer electronics, as opposed to implementing them individually using different modules. Furthermore, we utilize image enhancement for transmission map estimation instead of soft matting, thereby avoiding further computation complexity which would affect our goal of realizing high frame-rate real time processing. Our FPGA implementation, operating at an optimum frequency of 125MHz with 5.67M total block memory bit size, supports WUXGA (1,920×1,200) 60fps as well as 1080p60 color input. Our proposed design is competitive with existing state-of-the-art designs. Our proposal is tailored to enhance consumer electronic such as on-board cameras, active surveillance intrusion detection systems, autonomous cars, mobile streaming systems and robotics with low processing and memory requirements.

  • In situ Observation of Immobilization of Cytochrome c into Hydrophobic DNA Nano-Film

    Naoki MATSUDA  Hirotaka OKABE  Ayako OMURA  Miki NAKANO  Koji MIYAKE  Toshihiko NAGAMURA  Hideki KAWAI  

     
    BRIEF PAPER

      Vol:
    E102-C No:6
      Page(s):
    471-474

    Hydrophobic DNA (H-DNA) nano-film was formed as the surface modifier on a thin glass plate working as a slab optical waveguide (SOWF). Cytochrom c (cytc) molecules were immobilized from aqueous solution with direct contacting to the H-DNA nano-film for 30 minutes. From SOWG absorption spectral changes during automated solution exchange (SE) processes, it was found that about 28.1% of cytc molecules was immobilized in the H-DNA nano-film with keeping their reduction functionality by reducing reagent.

  • Feature Subset Selection for Ordered Logit Model via Tangent-Plane-Based Approximation

    Mizuho NAGANUMA  Yuichi TAKANO  Ryuhei MIYASHIRO  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2019/02/21
      Vol:
    E102-D No:5
      Page(s):
    1046-1053

    This paper is concerned with a mixed-integer optimization (MIO) approach to selecting a subset of relevant features from among many candidates. For ordinal classification, a sequential logit model and an ordered logit model are often employed. For feature subset selection in the sequential logit model, Sato et al.[22] recently proposed a mixed-integer linear optimization (MILO) formulation. In their MILO formulation, a univariate nonlinear function contained in the sequential logit model was represented by a tangent-line-based approximation. We extend this MILO formulation toward the ordered logit model, which is more commonly used for ordinal classification than the sequential logit model is. Making use of tangent planes to approximate a bivariate nonlinear function involved in the ordered logit model, we derive an MILO formulation for feature subset selection in the ordered logit model. Our computational results verify that the proposed method is superior to the L1-regularized ordered logit model in terms of solution quality.

  • 24GHz FMCW Radar Module for Pedestrian Detection in Crosswalks

    You-Sun WON  Dongseung SHIN  Miryong PARK  Sohee JUNG  Jaeho LEE  Cheolhyo LEE  Yunjeong SONG  

     
    BRIEF PAPER-Microwaves, Millimeter-Waves

      Vol:
    E102-C No:5
      Page(s):
    416-419

    This paper reports a 24GHz ISM band radar module for pedestrian detection in crosswalks. The radar module is composed of an RF transceiver board, a baseband board, and a microcontroller unit board. The radar signal is a sawtooth frequency-modulated continuous-wave signal with a center frequency of 24.15GHz, a bandwidth of 200MHz, a chirp length of 80µs, and a pulse repetition interval of 320µs. The radar module can detect a pedestrian on a crosswalk with a width of 4m and a length of 14m. The radar outputs the range, angle, and speed of the detected pedestrians every 50ms by radar signal processing and consumes 7.57W from 12V power supply. The size of the radar module is 110×70mm2.

  • RNA: An Accurate Residual Network Accelerator for Quantized and Reconstructed Deep Neural Networks

    Cheng LUO  Wei CAO  Lingli WANG  Philip H. W. LEONG  

     
    PAPER-Applications

      Pubricized:
    2019/02/19
      Vol:
    E102-D No:5
      Page(s):
    1037-1045

    With the continuous refinement of Deep Neural Networks (DNNs), a series of deep and complex networks such as Residual Networks (ResNets) show impressive prediction accuracy in image classification tasks. Unfortunately, the structural complexity and computational cost of residual networks make hardware implementation difficult. In this paper, we present the quantized and reconstructed deep neural network (QR-DNN) technique, which first inserts batch normalization (BN) layers in the network during training, and later removes them to facilitate efficient hardware implementation. Moreover, an accurate and efficient residual network accelerator (RNA) is presented based on QR-DNN with batch-normalization-free structures and weights represented in a logarithmic number system. RNA employs a systolic array architecture to perform shift-and-accumulate operations instead of multiplication operations. QR-DNN is shown to achieve a 1∼2% improvement in accuracy over existing techniques, and RNA over previous best fixed-point accelerators. An FPGA implementation on a Xilinx Zynq XC7Z045 device achieves 804.03 GOPS, 104.15 FPS and 91.41% top-5 accuracy for the ResNet-50 benchmark, and state-of-the-art results are also reported for AlexNet and VGG.

  • Variable Regularization Affine Projection Sign Algorithm in Impulsive Noisy Environment

    Ying-Ren CHIEN  

     
    LETTER-Digital Signal Processing

      Vol:
    E102-A No:5
      Page(s):
    725-728

    Affine projection sign algorithm (APSA) is an important adaptive filtering method to combat the impulsive noisy environment. However, the performance of APSA is poor, if its regularization parameter is not well chosen. We propose a variable regularization APSA (VR-APSA) approach, which adopts a gradient-based method to recursively reduce the norm of the a priori error vector. The resulting VR-APSA leverages the time correlation of both the input signal matrix and error vector to adjust the value of the regularization parameter. Simulation results confirm that our algorithm exhibits both fast convergence and small misadjustment properties.

  • Sum Throughput Maximization for MIMO Wireless Powered Communication Networks with Discrete Signal Inputs

    Feng KE  Xiaoyu HUANG  Weiliang ZENG  Yuqin LIU  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2018/10/26
      Vol:
    E102-B No:5
      Page(s):
    1037-1044

    Wireless powered communication networks (WPCNs) utilize the wireless energy transfer (WET) technique to facilitate the wireless information transmission (WIT) of nodes. We propose a two-step iterative algorithm to maximize the sum throughput of the users in a MIMO WPCN with discrete signal inputs. Firstly, the optimal solution of a convex power allocation problem can be found given a fixed time allocation; Secondly, a semi closed form solution for the optimal time allocation is obtained when fixing the power allocation matrix. By optimizing the power allocation and time allocation alternately, the two-step algorithm converges to a local optimal point. Simulation results show that the proposed algorithm outperforms the conventional schemes, which consider only Gaussian inputs.

  • Power Efficient Object Detector with an Event-Driven Camera for Moving Object Surveillance on an FPGA

    Masayuki SHIMODA  Shimpei SATO  Hiroki NAKAHARA  

     
    PAPER-Applications

      Pubricized:
    2019/02/27
      Vol:
    E102-D No:5
      Page(s):
    1020-1028

    We propose an object detector using a sliding window method for an event-driven camera which outputs a subtracted frame (usually a binary value) when changes are detected in captured images. Since sliding window skips unchanged portions of the output, the number of target object area candidates decreases dramatically, which means that our system operates faster and with lower power consumption than a system using a straightforward sliding window approach. Since the event-driven camera output consists of binary precision frames, an all binarized convolutional neural network (ABCNN) can be available, which means that it allows all convolutional layers to share the same binarized convolutional circuit, thereby reducing the area requirement. We implemented our proposed method on the Xilinx Inc. Zedboard and then evaluated it using the PETS 2009 dataset. The results showed that our system outperformed BCNN system from the viewpoint of detection performance, hardware requirement, and computation time. Also, we showed that FPGA is an ideal method for our system than mobile GPU. From these results, our proposed system is more suitable for the embedded systems based on stationary cameras (such as security cameras).

  • An Optimized Level Set Method Based on QPSO and Fuzzy Clustering

    Ling YANG  Yuanqi FU  Zhongke WANG  Xiaoqiong ZHEN  Zhipeng YANG  Xingang FAN  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2019/02/12
      Vol:
    E102-D No:5
      Page(s):
    1065-1072

    A new fuzzy level set method (FLSM) based on the global search capability of quantum particle swarm optimization (QPSO) is proposed to improve the stability and precision of image segmentation, and reduce the sensitivity of initialization. The new combination of QPSO-FLSM algorithm iteratively optimizes initial contours using the QPSO method and fuzzy c-means clustering, and then utilizes level set method (LSM) to segment images. The new algorithm exploits the global search capability of QPSO to obtain a stable cluster center and a pre-segmentation contour closer to the region of interest during the iteration. In the implementation of the new method in segmenting liver tumors, brain tissues, and lightning images, the fitness function of the objective function of QPSO-FLSM algorithm is optimized by 10% in comparison to the original FLSM algorithm. The achieved initial contours from the QPSO-FLSM algorithm are also more stable than that from the FLSM. The QPSO-FLSM resulted in improved final image segmentation.

  • Interference Suppression of Partially Overlapped Signals Using GSVD and Orthogonal Projection

    Liqing SHAN  Shexiang MA  Xin MENG  Long ZHOU  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2018/11/21
      Vol:
    E102-B No:5
      Page(s):
    1055-1060

    In order to solve the problem in Automatic Identification System (AIS) that the signal in the target slot cannot be correctly received due to partial overlap of signals in adjacent time slots, the paper introduces a new criterion: maximum expected signal power (MESP) and proposes a novel beamforming algorithm based on generalized singular value decomposition (GSVD) and orthogonal projection. The algorithm employs GSVD to estimate the signal subspace, and adopts orthogonal projection to project the received signal onto the orthogonal subspace of the non-target signal. Then, beamforming technique is used to maximize the output power of the target signal on the basis of MESP. Theoretical analysis and simulation results show the effectiveness of the proposed algorithm.

  • Quantum Algorithm on Logistic Regression Problem

    Jun Suk KIM  Chang Wook AHN  

     
    LETTER-Fundamentals of Information Systems

      Pubricized:
    2019/01/28
      Vol:
    E102-D No:4
      Page(s):
    856-858

    We examine the feasibility of Deutsch-Jozsa Algorithm, a basic quantum algorithm, on a machine learning-based logistic regression problem. Its major property to distinguish the function type with an exponential speedup can help identify the feature unsuitability much more quickly. Although strict conditions and restrictions to abide exist, we reconfirm the quantum superiority in many aspects of modern computing.

  • On the Linear Complexity of Binary Generalized Cyclotomic Sequences of Period 2pm+1qn+1

    Minghui YANG  Dongdai LIN  Qiuyan WANG  Jian GAO  

     
    LETTER-Cryptography and Information Security

      Vol:
    E102-A No:4
      Page(s):
    676-679

    In this paper, new classes of binary generalized cyclotomic sequences of period 2pm+1qn+1 are constructed. These sequences are balanced. We calculate the linear complexity of the constructed sequences with a simple method. The results show that the linear complexity of such sequences attains the maximum.

  • Spectrum-Based Fault Localization Framework to Support Fault Understanding Open Access

    Yong WANG  Zhiqiu HUANG  Yong LI  RongCun WANG  Qiao YU  

     
    LETTER-Software Engineering

      Pubricized:
    2019/01/15
      Vol:
    E102-D No:4
      Page(s):
    863-866

    A spectrum-based fault localization technique (SBFL), which identifies fault location(s) in a buggy program by comparing the execution statistics of the program spectra of passed executions and failed executions, is a popular automatic debugging technique. However, the usefulness of SBFL is mainly affected by the following two factors: accuracy and fault understanding in reality. To solve this issue, we propose a SBFL framework to support fault understanding. In the framework, we firstly localize a suspicious fault module to start debugging and then generate a weighted fault propagation graph (WFPG) for the hypothesis fault module, which weights the suspiciousness for the nodes to further perform block-level fault localization. In order to evaluate the proposed framework, we conduct a controlled experiment to compare two different module-level SBFL approaches and validate the effectiveness of WFPG. According to our preliminary experiments, the results are promising.

  • Compaction of Topological Quantum Circuits by Modularization

    Kota ASAI  Shigeru YAMASHITA  

     
    PAPER-VLSI Design Technology and CAD

      Vol:
    E102-A No:4
      Page(s):
    624-632

    A topological quantum circuit is a representation model for topological quantum computation, which attracts much attention recently as a promising fault-tolerant quantum computation model by using 3D cluster states. A topological quantum circuit can be considered as a set of “loops,” and we can transform the topology of loops without changing the functionality of the circuit if the transformation satisfies certain conditions. Thus, there have been proposed many researches to optimize topological quantum circuits by transforming the topology. There are two directions of research to optimize topological quantum circuits. The first group of research considers so-called a placement and wiring problem where we consider how to place “parts” in a 3D space which corresponds to already optimized sub-circuits. The second group of research focuses on how to optimize the structure and locations of loops in a relatively small circuit which is treated as one part in the above-mentioned first group of research. This paper proposes a new idea for the second group of research; our idea is to consider topological transformations as a placement and wiring problem for modules which we derive from the information how loops are crossed. By using such a formulation, we can use the techniques for placement and wiring problems, and successfully obtain an optimized solution. We confirm by our experiment that our method indeed can reduce the cost much more than the method by Paetznick and Fowler.

  • Detecting Communities and Correlated Attribute Clusters on Multi-Attributed Graphs

    Hiroyoshi ITO  Takahiro KOMAMIZU  Toshiyuki AMAGASA  Hiroyuki KITAGAWA  

     
    PAPER

      Pubricized:
    2019/02/04
      Vol:
    E102-D No:4
      Page(s):
    810-820

    Multi-attributed graphs, in which each node is characterized by multiple types of attributes, are ubiquitous in the real world. Detection and characterization of communities of nodes could have a significant impact on various applications. Although previous studies have attempted to tackle this task, it is still challenging due to difficulties in the integration of graph structures with multiple attributes and the presence of noises in the graphs. Therefore, in this study, we have focused on clusters of attribute values and strong correlations between communities and attribute-value clusters. The graph clustering methodology adopted in the proposed study involves Community detection, Attribute-value clustering, and deriving Relationships between communities and attribute-value clusters (CAR for short). Based on these concepts, the proposed multi-attributed graph clustering is modeled as CAR-clustering. To achieve CAR-clustering, a novel algorithm named CARNMF is developed based on non-negative matrix factorization (NMF) that can detect CAR in a cooperative manner. Results obtained from experiments using real-world datasets show that the CARNMF can detect communities and attribute-value clusters more accurately than existing comparable methods. Furthermore, clustering results obtained using the CARNMF indicate that CARNMF can successfully detect informative communities with meaningful semantic descriptions through correlations between communities and attribute-value clusters.

  • Public WLAN Virtualization for Multiple Services

    Kazuhiko KINOSHITA  Kazuki GINNAN  Keita KAWANO  Hiroki NAKAYAMA  Tsunemasa HAYASHI  Takashi WATANABE  

     
    PAPER-Network

      Pubricized:
    2018/10/10
      Vol:
    E102-B No:4
      Page(s):
    832-844

    The recent widespread use of high-performance terminals has resulted in a rapid increase in mobile data traffic. Therefore, public wireless local area networks (WLANs) are being used often to supplement the cellular networks. Capacity improvement through the dense deployment of access points (APs) is being considered. However, the effective throughput degrades significantly when many users connect to a single AP. In this paper, users are classified into guaranteed bit rate (GBR) users and best effort (BE) users, and we propose a network model to provide those services. In the proposed model, physical APs and the bandwidths are assigned to each service class dynamically using a virtual AP configuration and a virtualized backhaul network, for reducing the call-blocking probability of GBR users and improving the satisfaction degree of BE users. Finally, we evaluate the performance of the proposed model through simulation experiments and discuss its feasibility.

  • Non-Orthogonal Pilot Analysis for Single-Cell Massive MIMO Circumstances

    Pengxiang LI  Yuehong GAO  Zhidu LI  Hongwen YANG  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2018/10/05
      Vol:
    E102-B No:4
      Page(s):
    901-912

    This paper analyzes the performance of single-cell massive multiple-input multiple-output (MIMO) systems with non-orthogonal pilots. Specifically, closed-form expressions of the normalized channel estimation error and achievable uplink capacity are derived for both least squares (LS) and minimum mean square error (MMSE) estimation. Then a pilot reconstruction scheme based on orthogonal Procrustes principle (OPP) is provided to reduce the total normalized mean square error (NMSE) of channel estimations. With these reconstructed pilots, a two-step pilot assignment method is formulated by considering the correlation coefficient among pilots to reduce the maximum NMSE. Based on this assignment method, a step-by-step pilot power allocation scheme is further proposed to improve the average uplink signal-to-interference and noise ratio (SINR). At last, simulation results demonstrate the superiority of the proposed approaches.

641-660hit(5900hit)