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1061-1080hit(20498hit)

  • Statistical-Mechanical Analysis of Adaptive Volterra Filter with the LMS Algorithm Open Access

    Kimiko MOTONAKA  Tomoya KOSEKI  Yoshinobu KAJIKAWA  Seiji MIYOSHI  

     
    PAPER-Digital Signal Processing

      Pubricized:
    2021/06/01
      Vol:
    E104-A No:12
      Page(s):
    1665-1674

    The Volterra filter is one of the digital filters that can describe nonlinearity. In this paper, we analyze the dynamic behaviors of an adaptive signal-processing system including the Volterra filter by a statistical-mechanical method. On the basis of the self-averaging property that holds when the tapped delay line is assumed to be infinitely long, we derive simultaneous differential equations in a deterministic and closed form, which describe the behaviors of macroscopic variables. We obtain the exact solution by solving the equations analytically. In addition, the validity of the theory derived is confirmed by comparison with numerical simulations.

  • An Improved U-Net Architecture for Image Dehazing

    Wenyi GE  Yi LIN  Zhitao WANG  Guigui WANG  Shihan TAN  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2021/09/14
      Vol:
    E104-D No:12
      Page(s):
    2218-2225

    In this paper, we present a simple yet powerful deep neural network for natural image dehazing. The proposed method is designed based on U-Net architecture and we made some design changes to make it better. We first use Group Normalization to replace Batch Normalization to solve the problem of insufficient batch size due to hardware limitations. Second, we introduce FReLU activation into the U-Net block, which can achieve capturing complicated visual layouts with regular convolutions. Experimental results on public benchmarks demonstrate the effectiveness of the modified components. On the SOTS Indoor and Outdoor datasets, it obtains PSNR of 32.23 and 31.64 respectively, which are comparable performances with state-of-the-art methods. The code is publicly available online soon.

  • Analysis on Asymptotic Optimality of Round-Robin Scheduling for Minimizing Age of Information with HARQ Open Access

    Zhiyuan JIANG  Yijie HUANG  Shunqing ZHANG  Shugong XU  

     
    INVITED PAPER

      Pubricized:
    2021/07/01
      Vol:
    E104-B No:12
      Page(s):
    1465-1478

    In a heterogeneous unreliable multiaccess network, wherein terminals share a common wireless channel with distinct error probabilities, existing works have shown that a persistent round-robin (RR-P) scheduling policy can be arbitrarily worse than the optimum in terms of Age of Information (AoI) under standard Automatic Repeat reQuest (ARQ). In this paper, practical Hybrid ARQ (HARQ) schemes which are widely-used in today's wireless networks are considered. We show that RR-P is very close to optimum with asymptotically many terminals in this case, by explicitly deriving tight, closed-form AoI gaps between optimum and achievable AoI by RR-P. In particular, it is rigorously proved that for RR-P, under HARQ models concerning fading channels (resp. finite-blocklength regime), the relative AoI gap compared with the optimum is within a constant of 6.4% (resp. 6.2% with error exponential decay rate of 0.5). In addition, RR-P enjoys the distinctive advantage of implementation simplicity with channel-unaware and easy-to-decentralize operations, making it favorable in practice. A further investigation considering constraint imposed on the number of retransmissions is presented. The performance gap is indicated through numerical simulations.

  • Weighted PCA-LDA Based Color Quantization Method Suppressing Saturation Decrease

    Seiichi KOJIMA  Momoka HARADA  Yoshiaki UEDA  Noriaki SUETAKE  

     
    LETTER-Image

      Pubricized:
    2021/06/02
      Vol:
    E104-A No:12
      Page(s):
    1728-1732

    In this letter, we propose a new color quantization method suppressing saturation decrease. In the proposed method, saturation-based weight and intensity-based weight are used so that vivid colors are selected as the representative colors preferentially. Experiments show that the proposed method tends to select vivid colors even if they occupy only a small area in the image.

  • GECNN for Weakly Supervised Semantic Segmentation of 3D Point Clouds

    Zifen HE  Shouye ZHU  Ying HUANG  Yinhui ZHANG  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2021/09/24
      Vol:
    E104-D No:12
      Page(s):
    2237-2243

    This paper presents a novel method for weakly supervised semantic segmentation of 3D point clouds using a novel graph and edge convolutional neural network (GECNN) towards 1% and 10% point cloud with labels. Our general framework facilitates semantic segmentation by encoding both global and local scale features via a parallel graph and edge aggregation scheme. More specifically, global scale graph structure cues of point clouds are captured by a graph convolutional neural network, which is propagated from pairwise affinity representation over the whole graph established in a d-dimensional feature embedding space. We integrate local scale features derived from a dynamic edge feature aggregation convolutional neural networks that allows us to fusion both global and local cues of 3D point clouds. The proposed GECNN model is trained by using a comprehensive objective which consists of incomplete, inexact, self-supervision and smoothness constraints based on partially labeled points. The proposed approach enforces global and local consistency constraints directly on the objective losses. It inherently handles the challenges of segmenting sparse 3D point clouds with limited annotations in a large scale point cloud space. Our experiments on the ShapeNet and S3DIS benchmarks demonstrate the effectiveness of the proposed approach for efficient (within 20 epochs) learning of large scale point cloud semantics despite very limited labels.

  • Multimodal-Based Stream Integrated Neural Networks for Pain Assessment

    Ruicong ZHI  Caixia ZHOU  Junwei YU  Tingting LI  Ghada ZAMZMI  

     
    PAPER-Human-computer Interaction

      Pubricized:
    2021/09/10
      Vol:
    E104-D No:12
      Page(s):
    2184-2194

    Pain is an essential physiological phenomenon of human beings. Accurate assessment of pain is important to develop proper treatment. Although self-report method is the gold standard in pain assessment, it is not applicable to individuals with communicative impairment. Non-verbal pain indicators such as pain related facial expressions and changes in physiological parameters could provide valuable insights for pain assessment. In this paper, we propose a multimodal-based Stream Integrated Neural Network with Different Frame Rates (SINN) that combines facial expression and biomedical signals for automatic pain assessment. The main contributions of this research are threefold. (1) There are four-stream inputs of the SINN for facial expression feature extraction. The variant facial features are integrated with biomedical features, and the joint features are utilized for pain assessment. (2) The dynamic facial features are learned in both implicit and explicit manners to better represent the facial changes that occur during pain experience. (3) Multiple modalities are utilized to identify various pain states, including facial expression and biomedical signals. The experiments are conducted on publicly available pain datasets, and the performance is compared with several deep learning models. The experimental results illustrate the superiority of the proposed model, and it achieves the highest accuracy of 68.2%, which is up to 5% higher than the basic deep learning models on pain assessment with binary classification.

  • Formalization and Analysis of Ceph Using Process Algebra

    Ran LI  Huibiao ZHU  Jiaqi YIN  

     
    PAPER-Software System

      Pubricized:
    2021/09/28
      Vol:
    E104-D No:12
      Page(s):
    2154-2163

    Ceph is an object-based parallel distributed file system that provides excellent performance, reliability, and scalability. Additionally, Ceph provides its Cephx authentication system to authenticate users, so that it can identify users and realize authentication. In this paper, we first model the basic architecture of Ceph using process algebra CSP (Communicating Sequential Processes). With the help of the model checker PAT (Process Analysis Toolkit), we feed the constructed model to PAT and then verify several related properties, including Deadlock Freedom, Data Reachability, Data Write Integrity, Data Consistency and Authentication. The verification results show that the original model cannot cater to the Authentication property. Therefore, we formalize a new model of Ceph where Cephx is adopted. In the light of the new verification results, it can be found that Cephx satisfies all these properties.

  • Solving 3D Container Loading Problems Using Physics Simulation for Genetic Algorithm Evaluation

    Shuhei NISHIYAMA  Chonho LEE  Tomohiro MASHITA  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2021/08/06
      Vol:
    E104-D No:11
      Page(s):
    1913-1922

    In this work, an optimization method for the 3D container loading problem with multiple constraints is proposed. The method consists of a genetic algorithm to generate an arrangement of cargo and a fitness evaluation using a physics simulation. The fitness function considers not only the maximization of the container density and fitness value but also several different constraints such as weight, stack-ability, fragility, and orientation of cargo pieces. We employed a container shaking simulation for the fitness evaluation to include constraint effects during loading and transportation. We verified that the proposed method successfully provides the optimal cargo arrangement for small-scale problems with about 10 pieces of cargo.

  • Research on DoS Attacks Intrusion Detection Model Based on Multi-Dimensional Space Feature Vector Expansion K-Means Algorithm

    Lijun GAO  Zhenyi BIAN  Maode MA  

     
    PAPER-Fundamental Theories for Communications

      Pubricized:
    2021/04/22
      Vol:
    E104-B No:11
      Page(s):
    1377-1385

    DoS (Denial of Service) attacks are becoming one of the most serious security threats to global networks. We analyze the existing DoS detection methods and defense mechanisms in depth. In recent years, K-Means and improved variants have been widely examined for security intrusion detection, but the detection accuracy to data is not satisfactory. In this paper we propose a multi-dimensional space feature vector expansion K-Means model to detect threats in the network environment. The model uses a genetic algorithm to optimize the weight of K-Means multi-dimensional space feature vector, which greatly improves the detection rate against 6 typical Dos attacks. Furthermore, in order to verify the correctness of the model, this paper conducts a simulation on the NSL-KDD data set. The results show that the algorithm of multi-dimensional space feature vectors expansion K-Means improves the recognition accuracy to 96.88%. Furthermore, 41 kinds of feature vectors in NSL-KDD are analyzed in detail according to a large number of experimental training. The feature vector of the probability positive return of security attack detection is accurately extracted, and a comparison chart is formed to support subsequent research. A theoretical analysis and experimental results show that the multi-dimensional space feature vector expansion K-Means algorithm has a good application in the detection of DDos attacks.

  • Signature Codes to Remove Interference Light in Synchronous Optical Code-Division Multiple Access Systems Open Access

    Tomoko K. MATSUSHIMA  Shoichiro YAMASAKI  Kyohei ONO  

     
    PAPER-Coding Theory

      Pubricized:
    2021/05/06
      Vol:
    E104-A No:11
      Page(s):
    1619-1628

    This paper proposes a new class of signature codes for synchronous optical code-division multiple access (CDMA) and describes a general method for construction of the codes. The proposed codes can be obtained from generalized modified prime sequence codes (GMPSCs) based on extension fields GF(q), where q=pm, p is a prime number, and m is a positive integer. It has been reported that optical CDMA systems using GMPSCs remove not only multi-user interference but also optical interference (e.g., background light) with a constant intensity during a slot of length q2. Recently, the authors have reported that optical CDMA systems using GMPSCs also remove optical interference with intensity varying by blocks with a length of q. The proposed codes, referred to as p-chip codes in general and chip-pair codes in particular for the case of p=2, have the property of removing interference light with an intensity varying by shorter blocks with a length of p without requiring additional equipment. The present paper also investigates the algebraic properties and applications of the proposed codes.

  • Deployment and Reconfiguration for Balanced 5G Core Network Slices Open Access

    Xin LU  Xiang WANG  Lin PANG  Jiayi LIU  Qinghai YANG  Xingchen SONG  

     
    PAPER-Mobile Information Network and Personal Communications

      Pubricized:
    2021/05/21
      Vol:
    E104-A No:11
      Page(s):
    1629-1643

    Network Slicing (NS) is recognized as a key technology for the 5G network in providing tailored network services towards various types of verticals over a shared physical infrastructure. It offers the flexibility of on-demand provisioning of diverse services based on tenants' requirements in a dynamic environment. In this work, we focus on two important issues related to 5G Core slices: the deployment and the reconfiguration of 5G Core NSs. Firstly, for slice deployment, balancing the workloads of the underlying network is beneficial in mitigating resource fragmentation for accommodating the future unknown network slice requests. In this vein, we formulate a load-balancing oriented 5G Core NS deployment problem through an Integer Linear Program (ILP) formulation. Further, for slice reconfiguration, we propose a reactive strategy to accommodate a rejected NS request by reorganizing the already-deployed NSs. Typically, the NS deployment algorithm is reutilized with slacked physical resources to find out the congested part of the network, due to which the NS is rejected. Then, these congested physical nodes and links are reconfigured by migrating virtual network functions and virtual links, to re-balance the utilization of the whole physical network. To evaluate the performance of deployment and reconfiguration algorithms we proposed, extensive simulations have been conducted. The results show that our deployment algorithm performs better in resource balancing, hence achieves higher acceptance ratio by comparing to existing works. Moreover, our reconfiguration algorithm improves resource utilization by accommodating more NSs in a dynamic environment.

  • m-to-1 Mappings over Finite Fields Fq

    You GAO  Yun-Fei YAO  Lin-Zhi SHEN  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2021/04/28
      Vol:
    E104-A No:11
      Page(s):
    1612-1618

    Permutation polynomials over finite fields have been widely studied due to their important applications in mathematics and cryptography. In recent years, 2-to-1 mappings over finite fields were proposed to build almost perfect nonlinear functions, bent functions, and the semi-bent functions. In this paper, we generalize the 2-to-1 mappings to m-to-1 mappings, including their construction methods. Some applications of m-to-1 mappings are also discussed.

  • Determining Memory Polynomial Model Parameters from Those of Complex p-th Order Inverse for Designing Predistorter

    Michiharu NAKAMURA  Eisuke FUKUDA  Yoshimasa DAIDO  Keiichi MIZUTANI  Takeshi MATSUMURA  Hiroshi HARADA  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2021/06/01
      Vol:
    E104-B No:11
      Page(s):
    1429-1440

    Non-linear behavioral models play a key role in designing digital pre-distorters (DPDs) for non-linear power amplifiers (NLPAs). In general, more complex behavioral models have better capability, but they should be converted into simpler versions to assist implementation. In this paper, a conversion from a complex fifth order inverse of a parallel Wiener (PRW) model to a simpler memory polynomial (MP) model is developed by using frequency domain expressions. In the developed conversion, parameters of the converted MP model are calculated from those of original fifth order inverse and frequency domain statistics of the transmit signal. Since the frequency domain statistics of the transmit signal can be precalculated, the developed conversion is deterministic, unlike the conventional conversion that identifies a converted model from lengthy input and output data. Computer simulations are conducted to confirm that conversion error is sufficiently small and the converted MP model offers equivalent pre-distortion to the original fifth order inverse.

  • Dependence of Arc Duration and Contact Gap at Arc Extinction of Break Arcs Occurring in a 48VDC/10A-300A Resistive Circuit on Contact Opening Speed

    Haruko YAZAKI  Junya SEKIKAWA  

     
    PAPER-Electromechanical Devices and Components

      Pubricized:
    2021/04/01
      Vol:
    E104-C No:11
      Page(s):
    656-662

    Dependences of arc duration D and contact gap at arc extinction d on contact opening speed v are studied for break arcs generated in a 48VDC resistive circuit at constant contact opening speeds. The opening speed v is varied over a wide range from 0.05 to 0.5m/s. Circuit current while electrical contacts are closed I0 is varied to 10A, 20A, 50A, 100A, 200A, and 300A. The following results were obtained. For each current I0, the arc duration D decreased with increasing contact opening speed v. However, the D at I0=300A was shorter than that at I0=200A. On the other hand, the contact gap at arc extinction d tended to increase with increasing the I0. However, the d at I0=300A was shorter than that at I0=200A. The d was almost constant with increasing the v for each current I0 when the I0 was lower than 200A. However, the d became shorter when the v was slower at I0=200A and 300A. At the v=0.05m/s, for example, the d at I0=300A was shorter than that at I0=100A. To explain the cause of the results of the d, in addition, arc length just before extinction L were analyzed. The L tended to increase with increasing current I0. The L was almost constant with increasing the v when the I0 was lower than 200A. However, when I0=200A and 300A, the L tended to become longer when the v was slower. The characteristics of the d will be discussed using the analyzed results of the L and motion of break arcs. At higher currents at I0=200A and 300A, the shorter d at the slowest v was caused by wide motion of the arc spots on contact surfaces and larger deformation of break arcs.

  • A Simple and Compact Planar Balun with Slit Ground

    Ryosuke SUGA  Kazuto OSHIMA  Tomoki UWANO  

     
    BRIEF PAPER-Microwaves, Millimeter-Waves

      Pubricized:
    2021/04/09
      Vol:
    E104-C No:11
      Page(s):
    667-671

    In this paper, a planar balun having simple and compact features with slit ground was proposed. The operating frequency can be designed by the length and position of the defected ground slits. The 20 dB bandwidth of the common mode rejection ratio of the measuring balun was over 90%.

  • Evaluation Metrics for the Cost of Data Movement in Deep Neural Network Acceleration

    Hongjie XU  Jun SHIOMI  Hidetoshi ONODERA  

     
    PAPER

      Pubricized:
    2021/06/01
      Vol:
    E104-A No:11
      Page(s):
    1488-1498

    Hardware accelerators are designed to support a specialized processing dataflow for everchanging deep neural networks (DNNs) under various processing environments. This paper introduces two hardware properties to describe the cost of data movement in each memory hierarchy. Based on the hardware properties, this paper proposes a set of evaluation metrics that are able to evaluate the number of memory accesses and the required memory capacity according to the specialized processing dataflow. Proposed metrics are able to analytically predict energy, throughput, and area of a hardware design without detailed implementation. Once a processing dataflow and constraints of hardware resources are determined, the proposed evaluation metrics quickly quantify the expected hardware benefits, thereby reducing design time.

  • Dynamic Incentive Mechanism for Industrial Network Congestion Control

    Zhentian WU  Feng YAN  Zhihua YANG  Jingya YANG  

     
    LETTER-Information Network

      Pubricized:
    2021/07/29
      Vol:
    E104-D No:11
      Page(s):
    2015-2018

    This paper studies using price incentives to shift bandwidth demand from peak to non-peak periods. In particular, cost discounts decrease as peak monthly usage increases. We take into account the delay sensitivity of different apps: during peak hours, the usage of hard real-time applications (HRAS) is not counted in the user's monthly data cap, while the usage of other applications (OAS) is counted in the user's monthly data cap. As a result, users may voluntarily delay or abandon OAS in order to get a higher fee discount. Then, a new data rate control algorithm is proposed. The algorithm allocates the data rate according to the priority of the source, which is determined by two factors: (I) the allocated data rate; and (II) the waiting time.

  • Monocone Antenna with Short Elements on Wideband Choke Structure Using Composite Right/Left-Handed Coaxial Line

    Kazuya MATSUBAYASHI  Naobumi MICHISHITA  Hisashi MORISHITA  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2021/06/01
      Vol:
    E104-B No:11
      Page(s):
    1408-1418

    The composite right/left-handed (CRLH) coaxial line (CL) with wideband electromagnetic band gap (EBG) is applied to the wideband choke structure for a monocone antenna with short elements, and the resulting characteristics are considered. In the proposed antenna, impedance matching and leakage current suppression can be achieved across a wideband off. The lowest frequency (|S11| ≤ -10dB) of the proposed antenna is about the same as that of the monocone antenna on an infinite ground plane. In addition, the radiation patterns of the proposed antenna are close to the figure of eight in wideband. The proposed antenna is prototyped, and the validity of the simulation is verified through measurement.

  • Frank-Wolfe Algorithm for Learning SVM-Type Multi-Category Classifiers

    Kenya TAJIMA  Yoshihiro HIROHASHI  Esmeraldo ZARA  Tsuyoshi KATO  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2021/08/11
      Vol:
    E104-D No:11
      Page(s):
    1923-1929

    The multi-category support vector machine (MC-SVM) is one of the most popular machine learning algorithms. There are numerous MC-SVM variants, although different optimization algorithms were developed for diverse learning machines. In this study, we developed a new optimization algorithm that can be applied to several MC-SVM variants. The algorithm is based on the Frank-Wolfe framework that requires two subproblems, direction-finding and line search, in each iteration. The contribution of this study is the discovery that both subproblems have a closed form solution if the Frank-Wolfe framework is applied to the dual problem. Additionally, the closed form solutions on both the direction-finding and line search exist even for the Moreau envelopes of the loss functions. We used several large datasets to demonstrate that the proposed optimization algorithm rapidly converges and thereby improves the pattern recognition performance.

  • PDPM: A Patient-Defined Data Privacy Management with Nudge Theory in Decentralized E-Health Environments

    Seolah JANG  Sandi RAHMADIKA  Sang Uk SHIN  Kyung-Hyune RHEE  

     
    PAPER

      Pubricized:
    2021/08/24
      Vol:
    E104-D No:11
      Page(s):
    1839-1849

    A private decentralized e-health environment, empowered by blockchain technology, grants authorized healthcare entities to legitimately access the patient's medical data without relying on a centralized node. Every activity from authorized entities is recorded immutably in the blockchain transactions. In terms of privacy, the e-health system preserves a default privacy option as an initial state for every patient since the patients may frequently customize their medical data over time for several purposes. Moreover, adjustments in the patient's privacy contexts are often solely from the patient's initiative without any doctor or stakeholders' recommendation. Therefore, we design, implement, and evaluate user-defined data privacy utilizing nudge theory for decentralized e-health systems named PDPM to tackle these issues. Patients can determine the privacy of their medical records to be closed to certain parties. Data privacy management is dynamic, which can be executed on the blockchain via the smart contract feature. Tamper-proof user-defined data privacy can resolve the dispute between the e-health entities related to privacy management and adjustments. In short, the authorized entities cannot deny any changes since every activity is recorded in the ledgers. Meanwhile, the nudge theory technique supports providing the best patient privacy recommendations based on their behaviour activities even though the final decision rests on the patient. Finally, we demonstrate how to use PDPM to realize user-defined data privacy management in decentralized e-health environments.

1061-1080hit(20498hit)