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

Keyword Search Result

[Keyword] SI(16314hit)

601-620hit(16314hit)

  • BCGL: Binary Classification-Based Graph Layout

    Kai YAN  Tiejun ZHAO  Muyun YANG  

     
    PAPER-Computer Graphics

      Pubricized:
    2022/05/30
      Vol:
    E105-D No:9
      Page(s):
    1610-1619

    Graph layouts reveal global or local structures of graph data. However, there are few studies on assisting readers in better reconstructing a graph from a layout. This paper attempts to generate a layout whose edges can be reestablished. We reformulate the graph layout problem as an edge classification problem. The inputs are the vertex pairs, and the outputs are the edge existences. The trainable parameters are the laid-out coordinates of the vertices. We propose a binary classification-based graph layout (BCGL) framework in this paper. This layout aims to preserve the local structure of the graph and does not require the total similarity relationships of the vertices. We implement two concrete algorithms under the BCGL framework, evaluate our approach on a wide variety of datasets, and draw comparisons with several other methods. The evaluations verify the ability of the BCGL in local neighborhood preservation and its visual quality with some classic metrics.

  • DRoF-Based Optical Video Re-Transmission System with Adaptive Combination Compression for Rain Attenuated Satellite Broadcast Signals Open Access

    Ryota SHIINA  Toshihito FUJIWARA  Tomohiro TANIGUCHI  Shunsuke SARUWATARI  Takashi WATANABE  

     
    PAPER-Fiber-Optic Transmission for Communications

      Pubricized:
    2022/04/06
      Vol:
    E105-B No:9
      Page(s):
    1023-1032

    In order to further reduce the transmission rate of multi-channel satellite broadcast signals, whose carrier-to-noise ratio (CNR fluctuates due to rainfall attenuation, we propose a novel digitized radio-over-fiber (DRoF) -based optical re-transmission system based on adaptive combination compression for ultra-high definition (UHD) broadcasting satellite (BS)/communications satellite (CS) broadcast signals. The proposed system reduces the optical re-transmission rate of BS/CS signals as much as possible while handling input CNR fluctuations. Therefore, the transmission rate of communication signals in time-division multiplexing (TDM) transmission is ensured, and network sharing of communication signals and broadcast signals via passive optical network (PON) is realized. Based on the ITU-R P.618-13 prediction model, an experimental evaluation is performed using estimates of the long-term statistics of attenuation due to rainfall. The attenuation is evaluated as a percentage of the time that long-term re-transmission service is available. It is shown that the proposed system is able to accommodate a wide range of rainfall attenuation and achieve a 99.988% time percentage for the duration of service provision. In order to show the rate reduction effect of the proposed system, the quantization bit reduction effect as a function of the input CNR, which depends on rainfall attenuation, is experimentally confirmed. Experiments show that service operation time of 99.978% can be achieved by 3-bit transmission. This means a 62.5% reduction in transmission rate is realized compared to conventional fixed quantization. Furthermore, the average quantization bit number in our system for service operation times is 3.000, indicating that most service operation times are covered by just 3-bit transmission.

  • Dispersion on Intervals

    Tetsuya ARAKI  Hiroyuki MIYATA  Shin-ichi NAKANO  

     
    PAPER-Algorithms and Data Structures

      Pubricized:
    2022/03/08
      Vol:
    E105-A No:9
      Page(s):
    1181-1186

    Given a set of n disjoint intervals on a line and an integer k, we want to find k points in the intervals so that the minimum pairwise distance of the k points is maximized. Intuitively, given a set of n disjoint time intervals on a timeline, each of which is a time span we are allowed to check something, and an integer k, which is the number of times we will check something, we plan k checking times so that the checks occur at equal time intervals as much as possible, that is, we want to maximize the minimum time interval between the k checking times. We call the problem the k-dispersion problem on intervals. If we need to choose exactly one point in each interval, so k=n, and the disjoint intervals are given in the sorted order on the line, then two O(n) time algorithms to solve the problem are known. In this paper we give the first O(n) time algorithm to solve the problem for any constant k. Our algorithm works even if the disjoint intervals are given in any (not sorted) order. If the disjoint intervals are given in the sorted order on the line, then, by slightly modifying the algorithm, one can solve the problem in O(log n) time. This is the first sublinear time algorithm to solve the problem. Also we show some results on the k-dispersion problem on disks, including an FPTAS.

  • Interpretation Method of Inversion Phenomena on Backward Transient Scattered Field Components by a Coated Metal Cylinder

    Toru KAWANO  Keiji GOTO  

     
    PAPER-Electromagnetic Theory

      Pubricized:
    2022/02/24
      Vol:
    E105-C No:9
      Page(s):
    389-397

    An interpretation method of inversion phenomena is newly proposed for backward transient scattered field components for both E- and H-polarizations when an ultra-wideband (UWB) pulse wave radiated from a line source is incident on a two-dimensional metal cylinder covered with a lossless dielectric medium layer (coated metal cylinder). A time-domain (TD) asymptotic solution, which is referred to as a TD saddle point technique (TD-SPT), is derived by applying the SPT in evaluating a backward transient scattered field which is expressed by an integral form. The TD-SPT is represented by a combination of a direct geometric optical ray (DGO) and a reflected GO (RGO) series, thereby being able to extract and calculate any backward transient scattered field component from a response waveform. The TD-SPT is useful in understanding the response waveform of a backward transient scattered field by a coated metal cylinder because it can give us the peak value and arrival time of any field component, namely DGO and RGO components, and interpret analytically inversion phenomenon of any field component. The accuracy, validity, and practicality of the TD-SPT are clarified by comparing it with two kinds of reference solutions.

  • Bayesian Optimization Methods for Inventory Control with Agent-Based Supply-Chain Simulator Open Access

    Takahiro OGURA  Haiyan WANG  Qiyao WANG  Atsuki KIUCHI  Chetan GUPTA  Naoshi UCHIHIRA  

     
    PAPER-Mathematical Systems Science

      Pubricized:
    2022/02/25
      Vol:
    E105-A No:9
      Page(s):
    1348-1357

    We propose a penalty-based and constraint Bayesian optimization methods with an agent-based supply-chain (SC) simulator as a new Monte Carlo optimization approach for multi-echelon inventory management to improve key performance indicators such as inventory cost and sales opportunity loss. First, we formulate the multi-echelon inventory problem and introduce an agent-based SC simulator architecture for the optimization. Second, we define the optimization framework for the formulation. Finally, we discuss the evaluation of the effectiveness of the proposed methods by benchmarking it against the most commonly used genetic algorithm (GA) in simulation-based inventory optimization. Our results indicate that the constraint Bayesian optimization can minimize SC inventory cost with lower sales opportunity loss rates and converge to the optimal solution 22 times faster than GA in the best case.

  • Online Removable Knapsack Problem for Integer-Sized Unweighted Items Open Access

    Hiroshi FUJIWARA  Kanaho HANJI  Hiroaki YAMAMOTO  

     
    PAPER-Algorithms and Data Structures

      Pubricized:
    2022/03/08
      Vol:
    E105-A No:9
      Page(s):
    1195-1202

    In the online removable knapsack problem, a sequence of items, each labeled with its value and its size, is given one by one. At each arrival of an item, a player has to decide whether to put it into a knapsack or to discard it. The player is also allowed to discard some of the items that are already in the knapsack. The objective is to maximize the total value of the knapsack. Iwama and Taketomi gave an optimal algorithm for the case where the value of each item is equal to its size. In this paper we consider a case with an additional constraint that the capacity of the knapsack is a positive integer N and that the sizes of items are all integral. For each positive integer N, we design an algorithm and prove its optimality. It is revealed that the competitive ratio is not monotonic with respect to N.

  • Asynchronous Periodic Interference Signals Cancellation in Frequency Domain

    Satoshi DENNO  Yafei HOU  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2022/03/24
      Vol:
    E105-B No:9
      Page(s):
    1087-1096

    This paper proposes a novel interference cancellation technique that prevents radio receivers from degrading due to periodic interference signals caused by electromagnetic waves emitted from high power circuits. The proposed technique cancels periodic interference signals in the frequency domain, even if the periodic interference signals drift in the time domain. We propose a drift estimation based on a super resolution technique such as ESPRIT. Moreover, we propose a sequential drift estimation to enhance the drift estimation performance. The proposed technique employs a linear filter based on the minimum mean square error criterion with assistance of the estimated drifts for the interference cancellation. The performance of the proposed technique is confirmed by computer simulation. The proposed technique achieves a gain of more than 40dB at the higher frequency part in the band. The proposed canceler achieves such superior performance, if the parameter sets are carefully selected. The proposed sequential drift estimation relaxes the parameter constraints, and enables the proposed cancellation to achieve the performance upper bound.

  • An Underwater DOA Estimation Method under Unknown Acoustic Velocity with L-Shaped Array for Wide-Band Signals

    Gengxin NING  Yushen LIN  Shenjie JIANG  Jun ZHANG  

     
    PAPER-Digital Signal Processing

      Pubricized:
    2022/03/09
      Vol:
    E105-A No:9
      Page(s):
    1289-1297

    The performance of conventional direction of arrival (DOA) methods is susceptible to the uncertainty of acoustic velocity in the underwater environment. To solve this problem, an underwater DOA estimation method with L-shaped array for wide-band signals under unknown acoustic velocity is proposed in this paper. The proposed method refers to the idea of incoherent signal subspace method and Root-MUSIC to obtain two sets of average roots corresponding to the subarray of the L-shaped array. And the geometric relationship between two vertical linear arrays is employed to derive the expression of DOA estimation with respect to the two average roots. The acoustic velocity variable in the DOA estimation expression can be eliminated in the proposed method. The simulation results demonstrate that the proposed method is more accurate and robust than other methods in an unknown acoustic velocity environment.

  • Altered Fingerprints Detection Based on Deep Feature Fusion

    Chao XU  Yunfeng YAN  Lehangyu YANG  Sheng LI  Guorui FENG  

     
    LETTER-Image Processing and Video Processing

      Pubricized:
    2022/06/13
      Vol:
    E105-D No:9
      Page(s):
    1647-1651

    The altered fingerprints help criminals escape from police and cause great harm to the society. In this letter, an altered fingerprint detection method is proposed. The method is constructed by two deep convolutional neural networks to train the time-domain and frequency-domain features. A spectral attention module is added to connect two networks. After the extraction network, a feature fusion module is then used to exploit relationship of two network features. We make ablation experiments and add the module proposed in some popular architectures. Results show the proposed method can improve the performance of altered fingerprint detection compared with the recent neural networks.

  • MSFF: A Multi-Scale Feature Fusion Network for Surface Defect Detection of Aluminum Profiles

    Lianshan SUN  Jingxue WEI  Hanchao DU  Yongbin ZHANG  Lifeng HE  

     
    LETTER-Image Recognition, Computer Vision

      Pubricized:
    2022/05/30
      Vol:
    E105-D No:9
      Page(s):
    1652-1655

    This paper presents an improved YOLOv3 network, named MSFF-YOLOv3, for precisely detecting variable surface defects of aluminum profiles in practice. First, we introduce a larger prediction scale to provide detailed information for small defect detection; second, we design an efficient attention-guided block to extract more features of defects with less overhead; third, we design a bottom-up pyramid and integrate it with the existing feature pyramid network to construct a twin-tower structure to improve the circulation and fusion of features of different layers. In addition, we employ the K-median algorithm for anchor clustering to speed up the network reasoning. Experimental results showed that the mean average precision of the proposed network MSFF-YOLOv3 is higher than all conventional networks for surface defect detection of aluminum profiles. Moreover, the number of frames processed per second for our proposed MSFF-YOLOv3 could meet real-time requirements.

  • Integral Cryptanalysis on Reduced-Round KASUMI

    Nobuyuki SUGIO  Yasutaka IGARASHI  Sadayuki HONGO  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2022/04/22
      Vol:
    E105-A No:9
      Page(s):
    1309-1316

    Integral cryptanalysis is one of the most powerful attacks on symmetric key block ciphers. Attackers preliminarily search integral characteristics of a target cipher and use them to perform the key recovery attack. Todo proposed a novel technique named the bit-based division property to find integral characteristics. Xiang et al. extended the Mixed Integer Linear Programming (MILP) method to search integral characteristics of lightweight block ciphers based on the bit-based division property. In this paper, we apply these techniques to the symmetric key block cipher KASUMI which was developed by modifying MISTY1. As a result, we found new 4.5-round characteristics of KASUMI for the first time. We show that 7-round KASUMI is attackable with 263 data and 2120 encryptions.

  • Single Suction Grasp Detection for Symmetric Objects Using Shallow Networks Trained with Synthetic Data

    Suraj Prakash PATTAR  Tsubasa HIRAKAWA  Takayoshi YAMASHITA  Tetsuya SAWANOBORI  Hironobu FUJIYOSHI  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2022/06/21
      Vol:
    E105-D No:9
      Page(s):
    1600-1609

    Predicting the grasping point accurately and quickly is crucial for successful robotic manipulation. However, to commercially deploy a robot, such as a dishwasher robot in a commercial kitchen, we also need to consider the constraints of limited usable resources. We present a deep learning method to predict the grasp position when using a single suction gripper for picking up objects. The proposed method is based on a shallow network to enable lower training costs and efficient inference on limited resources. Costs are further reduced by collecting data in a custom-built synthetic environment. For evaluating the proposed method, we developed a system that models a commercial kitchen for a dishwasher robot to manipulate symmetric objects. We tested our method against a model-fitting method and an algorithm-based method in our developed commercial kitchen environment and found that a shallow network trained with only the synthetic data achieves high accuracy. We also demonstrate the practicality of using a shallow network in sequence with an object detector for ease of training, prediction speed, low computation cost, and easier debugging.

  • Fast Gated Recurrent Network for Speech Synthesis

    Bima PRIHASTO  Tzu-Chiang TAI  Pao-Chi CHANG  Jia-Ching WANG  

     
    LETTER-Speech and Hearing

      Pubricized:
    2022/06/10
      Vol:
    E105-D No:9
      Page(s):
    1634-1638

    The recurrent neural network (RNN) has been used in audio and speech processing, such as language translation and speech recognition. Although RNN-based architecture can be applied to speech synthesis, the long computing time is still the primary concern. This research proposes a fast gated recurrent neural network, a fast RNN-based architecture, for speech synthesis based on the minimal gated unit (MGU). Our architecture removes the unit state history from some equations in MGU. Our MGU-based architecture is about twice faster, with equally good sound quality than the other MGU-based architectures.

  • Sensitivity Enhanced Edge-Cloud Collaborative Trust Evaluation in Social Internet of Things

    Peng YANG  Yu YANG  Puning ZHANG  Dapeng WU  Ruyan WANG  

     
    PAPER-Network Management/Operation

      Pubricized:
    2022/03/22
      Vol:
    E105-B No:9
      Page(s):
    1053-1062

    The integration of social networking concepts into the Internet of Things has led to the Social Internet of Things (SIoT) paradigm, and trust evaluation is essential to secure interaction in SIoT. In SIoT, when resource-constrained nodes respond to unexpected malicious services and malicious recommendations, the trust assessment is prone to be inaccurate, and the existing architecture has the risk of privacy leakage. An edge-cloud collaborative trust evaluation architecture in SIoT is proposed in this paper. Utilize the resource advantages of the cloud and the edge to complete the trust assessment task collaboratively. An evaluation algorithm of relationship closeness between nodes is designed to evaluate neighbor nodes' reliability in SIoT. A trust computing algorithm with enhanced sensitivity is proposed, considering the fluctuation of trust value and the conflict between trust indicators to enhance the sensitivity of identifying malicious behaviors. Simulation results show that compared with traditional methods, the proposed trust evaluation method can effectively improve the success rate of interaction and reduce the false detection rate when dealing with malicious services and malicious recommendations.

  • Compressed Sensing Based Power Allocation and User Selection with Adaptive Resource Block Selection for Downlink NOMA Systems

    Tomofumi MAKITA  Osamu MUTA  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2022/02/18
      Vol:
    E105-B No:8
      Page(s):
    959-968

    The application of compressed sensing (CS) theory to non-orthogonal multiple access (NOMA) systems has been investigated recently. As described in this paper, we propose a quality-of-service (QoS)-aware, low-complexity, CS-based user selection and power allocation scheme with adaptive resource block selection for downlink NOMA systems, where the tolerable interference threshold is designed mathematically to achieve a given QoS requirement by being relaxed to a constrained l1 norm optimization problem. The proposed scheme adopts two adaptive resource block (RB) selection algorithms that assign proper RB to user pairs, i.e. max-min channel assignment and two-step opportunistic channel assignment. Simulation results show that the proposed scheme is more effective at improving the user rate than other reference schemes while reducing the required complexity. The QoS requirement is approximately satisfied as long as the required QoS value is feasible.

  • Constant Voltage Design Using K-Inverter for Cooperative Inductive Power Transfer Open Access

    Quoc-Trinh VO  Quang-Thang DUONG  Minoru OKADA  

     
    PAPER-Electromagnetic Theory

      Pubricized:
    2022/01/31
      Vol:
    E105-C No:8
      Page(s):
    358-368

    This paper proposes constant voltage design based on K-inverter for cooperative inductive power transfer (IPT) where a nearby receiver picks up power and simultaneously cooperates in relaying the signal toward another distant receiver. In a cooperative IPT system, wireless power is fundamentally transferred to the nearby receiver via one K-inverter and to the distant receiver via two K-inverters. By adding one more K-inverter to the nearby receiver, our design is among the simplest methods as it delivers constant output voltage to each receiver via two K-inverters only. Experimental results verify that the proposed cooperative IPT system can stabilize two output voltages against the load variations while attaining high RF-RF efficiency of 90%.

  • Diabetes Noninvasive Recognition via Improved Capsule Network

    Cunlei WANG  Donghui LI  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2022/05/06
      Vol:
    E105-D No:8
      Page(s):
    1464-1471

    Noninvasive recognition is an important trend in diabetes recognition. Unfortunately, the accuracy obtained from the conventional noninvasive recognition methods is low. This paper proposes a novel Diabetes Noninvasive Recognition method via the plantar pressure image and improved Capsule Network (DNR-CapsNet). The input of the proposed method is a plantar pressure image, and the output is the recognition result: healthy or possibly diabetes. The ResNet18 is used as the backbone of the convolutional layers to convert pixel intensities to local features in the proposed DNR-CapsNet. Then, the PrimaryCaps layer, SecondaryCaps layer, and DiabetesCaps layer are developed to achieve the diabetes recognition. The semantic fusion and locality-constrained dynamic routing are also developed to further improve the recognition accuracy in our method. The experimental results indicate that the proposed method has a better performance on diabetes noninvasive recognition than the state-of-the-art methods.

  • Mach-Zehnder Optical Modulator Integrated with Tunable Multimode Interference Coupler of Ti:LiNbO3 Waveguides for Controlling Modulation Extinction Ratio

    Anna HIRAI  Yuichi MATSUMOTO  Takanori SATO  Tadashi KAWAI  Akira ENOKIHARA  Shinya NAKAJIMA  Atsushi KANNO  Naokatsu YAMAMOTO  

     
    BRIEF PAPER-Lasers, Quantum Electronics

      Pubricized:
    2022/02/16
      Vol:
    E105-C No:8
      Page(s):
    385-388

    A Mach-Zehnder optical modulator with the tunable multimode interference coupler was fabricated using Ti-diffused LiNbO3. The modulation extinction ratio could be voltage controlled to maximize up to 50 dB by tuning the coupler. Optical single-sideband modulation was also achieved with a sideband suppression ratio of more than 30 dB.

  • BFF R-CNN: Balanced Feature Fusion for Object Detection

    Hongzhe LIU  Ningwei WANG  Xuewei LI  Cheng XU  Yaze LI  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2022/05/17
      Vol:
    E105-D No:8
      Page(s):
    1472-1480

    In the neck part of a two-stage object detection network, feature fusion is generally carried out in either a top-down or bottom-up manner. However, two types of imbalance may exist: feature imbalance in the neck of the model and gradient imbalance in the region of interest extraction layer due to the scale changes of objects. The deeper the network is, the more abstract the learned features are, that is to say, more semantic information can be extracted. However, the extracted image background, spatial location, and other resolution information are less. In contrast, the shallow part can learn little semantic information, but a lot of spatial location information. We propose the Both Ends to Centre to Multiple Layers (BEtM) feature fusion method to solve the feature imbalance problem in the neck and a Multi-level Region of Interest Feature Extraction (MRoIE) layer to solve the gradient imbalance problem. In combination with the Region-based Convolutional Neural Network (R-CNN) framework, our Balanced Feature Fusion (BFF) method offers significantly improved network performance compared with the Faster R-CNN architecture. On the MS COCO 2017 dataset, it achieves an average precision (AP) that is 1.9 points and 3.2 points higher than those of the Feature Pyramid Network (FPN) Faster R-CNN framework and the Generic Region of Interest Extractor (GRoIE) framework, respectively.

  • Multiple Hypothesis Tracking with Merged Bounding Box Measurements Considering Occlusion

    Tetsutaro YAMADA  Masato GOCHO  Kei AKAMA  Ryoma YATAKA  Hiroshi KAMEDA  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2022/05/09
      Vol:
    E105-D No:8
      Page(s):
    1456-1463

    A new approach for multi-target tracking in an occlusion environment is presented. In pedestrian tracking using a video camera, pedestrains must be tracked accurately and continuously in the images. However, in a crowded environment, the conventional tracking algorithm has a problem in that tracks do not continue when pedestrians are hidden behind the foreground object. In this study, we propose a robust tracking method for occlusion that introduces a degeneration hypothesis that relaxes the track hypothesis which has one measurement to one track constraint. The proposed method relaxes the hypothesis that one measurement and multiple trajectories are associated based on the endpoints of the bounding box when the predicted trajectory is approaching, therefore the continuation of the tracking is improved using the measurement in the foreground. A numerical evaluation using MOT (Multiple Object Tracking) image data sets is performed to demonstrate the effectiveness of the proposed algorithm.

601-620hit(16314hit)