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801-820hit(22683hit)

  • 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.

  • Convergence Acceleration via Chebyshev Step: Plausible Interpretation of Deep-Unfolded Gradient Descent

    Satoshi TAKABE  Tadashi WADAYAMA  

     
    PAPER-Numerical Analysis and Optimization

      Pubricized:
    2022/01/25
      Vol:
    E105-A No:8
      Page(s):
    1110-1120

    Deep unfolding is a promising deep-learning technique, whose network architecture is based on expanding the recursive structure of existing iterative algorithms. Although deep unfolding realizes convergence acceleration, its theoretical aspects have not been revealed yet. This study details the theoretical analysis of the convergence acceleration in deep-unfolded gradient descent (DUGD) whose trainable parameters are step sizes. We propose a plausible interpretation of the learned step-size parameters in DUGD by introducing the principle of Chebyshev steps derived from Chebyshev polynomials. The use of Chebyshev steps in gradient descent (GD) enables us to bound the spectral radius of a matrix governing the convergence speed of GD, leading to a tight upper bound on the convergence rate. Numerical results show that Chebyshev steps numerically explain the learned step-size parameters in DUGD well.

  • How to Extend CTRT for AES-256 and AES-192

    SeongHan SHIN  Shota YAMADA  Goichiro HANAOKA  Yusuke ISHIDA  Atsushi KUNII  Junichi OKETANI  Shimpei KUNII  Kiyoshi TOMOMURA  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2022/02/16
      Vol:
    E105-A No:8
      Page(s):
    1121-1133

    AONT (All-or-Nothing Transform) is a kind of (n, n)-threshold secret sharing scheme that distributes a message m into a set of n shares such that the message m can be reconstructed if and only if n shares are collected. At CRYPTO 2000, Desai proposed a simple and faster AONT based on the CTR mode of encryption (called CTRT) and proved its security in the ideal cipher model. Though AES-128, whose key length k = 128 and block length l = 128, can be used in CTRT as a block cipher, AES-256 and AES-192 cannot be used due to its intrinsic restriction of k ≤ l. In this paper, we propose an extended CTRT (for short, XCTRT) suitable for AES-256. By thoroughly evaluating all the tricky cases, we prove that XCTRT is secure in the ideal cipher model under the same CTRT security definition. Also, we discuss the security result of XCTRT in concrete parameter settings. For more flexibility of key length, we propose a variant of XCTRT dealing with l

  • On Cryptographic Parameters of Permutation Polynomials of the form xrh(x(2n-1)/d)

    Jaeseong JEONG  Chang Heon KIM  Namhun KOO  Soonhak KWON  Sumin LEE  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2022/02/22
      Vol:
    E105-A No:8
      Page(s):
    1134-1146

    The differential uniformity, the boomerang uniformity, and the extended Walsh spectrum etc are important parameters to evaluate the security of S (substitution)-box. In this paper, we introduce efficient formulas to compute these cryptographic parameters of permutation polynomials of the form xrh(x(2n-1)/d) over a finite field of q=2n elements, where r is a positive integer and d is a positive divisor of 2n-1. The computational cost of those formulas is proportional to d. We investigate differentially 4-uniform permutation polynomials of the form xrh(x(2n-1)/3) and compute the boomerang spectrum and the extended Walsh spectrum of them using the suggested formulas when 6≤n≤12 is even, where d=3 is the smallest nontrivial d for even n. We also investigate the differential uniformity of some permutation polynomials introduced in some recent papers for the case d=2n/2+1.

  • Ray Tracing Acceleration using Rank Minimization for Radio Map Simulation

    Norisato SUGA  Ryohei SASAKI  

     
    LETTER-Digital Signal Processing

      Pubricized:
    2022/02/22
      Vol:
    E105-A No:8
      Page(s):
    1157-1161

    In this letter, a ray tracing (RT) acceleration method based on rank minimization is proposed. RT is a general tool used to simulate wireless communication environments. However, the simulation is time consuming because of the large number of ray calculations. This letter focuses on radio map interpolation as an acceleration approach. In the conventional methods cannot appropriately estimate short-span variation caused by multipath fading. To overcome the shortage of the conventional methods, we adopt rank minimization based interpolation. A computational simulation using commercial RT software revealed that the interpolation accuracy of the proposed method was higher than those of other radio map interpolation methods and that RT simulation can be accelerated approximate five times faster with the missing rate of 0.8.

  • New Constructions of Quadriphase Periodic Almost-Complementary Pairs

    Tao YU  Yang YANG  Hua MENG  Yong WANG  

     
    LETTER-Coding Theory

      Pubricized:
    2022/02/04
      Vol:
    E105-A No:8
      Page(s):
    1165-1169

    Almost-complementary pairs (ACPs) are sequence pairs whose autocorrelations sum up to zero at all but one non-zero time-shifts. Periodic ACPs (P-ACPs) display almost similar correlation properties to that of the periodic complementary pairs (PCPs). In this letter, we propose systematic constructions of quadriphase P-ACPs (QP-ACPs) from aperiodic (periodic) complementary pairs and almost perfect binary (quadriphase) sequences. The proposed construction gives QP-ACPs of new lengths which are not covered in the literature.

  • 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.

  • An Interpretable Feature Selection Based on Particle Swarm Optimization

    Yi LIU  Wei QIN  Qibin ZHENG  Gensong LI  Mengmeng LI  

     
    LETTER-Pattern Recognition

      Pubricized:
    2022/05/09
      Vol:
    E105-D No:8
      Page(s):
    1495-1500

    Feature selection based on particle swarm optimization is often employed for promoting the performance of artificial intelligence algorithms. However, its interpretability has been lacking of concrete research. Improving the stability of the feature selection method is a way to effectively improve its interpretability. A novel feature selection approach named Interpretable Particle Swarm Optimization is developed in this paper. It uses four data perturbation ways and three filter feature selection methods to obtain stable feature subsets, and adopts Fuch map to convert them to initial particles. Besides, it employs similarity mutation strategy, which applies Tanimoto distance to choose the nearest 1/3 individuals to the previous particles to implement mutation. Eleven representative algorithms and four typical datasets are taken to make a comprehensive comparison with our proposed approach. Accuracy, F1, precision and recall rate indicators are used as classification measures, and extension of Kuncheva indicator is employed as the stability measure. Experiments show that our method has a better interpretability than the compared evolutionary algorithms. Furthermore, the results of classification measures demonstrate that the proposed approach has an excellent comprehensive classification performance.

  • A Hierarchical Memory Model for Task-Oriented Dialogue System

    Ya ZENG  Li WAN  Qiuhong LUO  Mao CHEN  

     
    PAPER-Natural Language Processing

      Pubricized:
    2022/05/16
      Vol:
    E105-D No:8
      Page(s):
    1481-1489

    Traditional pipeline methods for task-oriented dialogue systems are designed individually and expensively. Existing memory augmented end-to-end methods directly map the inputs to outputs and achieve promising results. However, the most existing end-to-end solutions store the dialogue history and knowledge base (KB) information in the same memory and represent KB information in the form of KB triples, making the memory reader's reasoning on the memory more difficult, which makes the system difficult to retrieve the correct information from the memory to generate a response. Some methods introduce many manual annotations to strengthen reasoning. To reduce the use of manual annotations, while strengthening reasoning, we propose a hierarchical memory model (HM2Seq) for task-oriented systems. HM2Seq uses a hierarchical memory to separate the dialogue history and KB information into two memories and stores KB in KB rows, then we use memory rows pointer combined with an entity decoder to perform hierarchical reasoning over memory. The experimental results on two publicly available task-oriented dialogue datasets confirm our hypothesis and show the outstanding performance of our HM2Seq by outperforming the baselines.

  • A Slotted Access-Inspired Group Paging Scheme for Resource Efficiency in Cellular MTC Networks

    Linh T. HOANG  Anh-Tuan H. BUI  Chuyen T. NGUYEN  Anh T. PHAM  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2022/02/14
      Vol:
    E105-B No:8
      Page(s):
    944-958

    Deployment of machine-type communications (MTCs) over the current cellular network could lead to severe overloading of the radio access network of Long Term Evolution (LTE)-based systems. This paper proposes a slotted access-based solution, called the Slotted Access For Group Paging (SAFGP), to cope with the paging-induced MTC traffic. The proposed SAFGP splits paged devices into multiple access groups, and each group is then allocated separate radio resources on the LTE's Physical Random Access Channel (PRACH) in a periodic manner during the paging interval. To support the proposed scheme, a new adaptive barring algorithm is proposed to stabilize the number of successful devices in each dedicated access slot. The objective is to let as few devices transmitting preambles in an access slot as possible while ensuring that the number of preambles selected by exactly one device approximates the maximum number of uplink grants that can be allocated by the eNB for an access slot. Analysis and simulation results demonstrate that, given the same amount of time-frequency resources, the proposed method significantly improves the access success and resource utilization rates at the cost of slightly increasing the access delay compared to state-of-the-art methods.

  • 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.

  • Faster Final Exponentiation on the KSS18 Curve

    Shi Ping CAI  Zhi HU  Chang An ZHAO  

     
    LETTER-Cryptography and Information Security

      Pubricized:
    2022/02/22
      Vol:
    E105-A No:8
      Page(s):
    1162-1164

    The final exponentiation affects the efficiency of pairing computations especially on pairing-friendly curves with high embedding degree. We propose an efficient method for computing the hard part of the final exponentiation on the KSS18 curve at the 192-bit security level. Implementations indicate that the computation of the final exponentiation is 8.74% faster than the previously fastest result.

  • Control of Radiation Direction in an Aperture Array Excited by a Waveguide 2-Plane Hybrid Coupler

    Yuki SUNAGUCHI  Takashi TOMURA  Jiro HIROKAWA  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2022/02/10
      Vol:
    E105-B No:8
      Page(s):
    906-912

    This paper details the design of a plate that controls the beam direction in an aperture array excited by a waveguide 2-plane hybrid coupler. The beam direction can be controlled in the range of ±15-32deg. in the quasi H-plane, and ±26-54deg. in the quasi E-plane at the design frequency of 66.425GHz. Inductive irises are introduced into tapered waveguides in the plate and the reflection is suppressed by narrow apertures. A plate that has a larger tilt angle in the quasi E-plane and another plate with conventional rectangular waveguide ports as a reference are fabricated and measured. The measured values agree well with the simulation results.

  • Ambipolar Conduction of λ-DNA Transistor Fabricated on SiO2/Si Structure

    Naoto MATSUO  Kazuki YOSHIDA  Koji SUMITOMO  Kazushige YAMANA  Tetsuo TABEI  

     
    PAPER-Semiconductor Materials and Devices

      Pubricized:
    2022/01/26
      Vol:
    E105-C No:8
      Page(s):
    369-374

    This paper reports on the ambipolar conduction for the λ-Deoxyribonucleic Acid (DNA) field effect transistor (FET) with 450, 400 and 250 base pair experimentally and theoretically. It was found that the drain current of the p-type DNA/Si FET increased as the ratio of the guanine-cytosine (GC) pair increased and that of the n-type DNA/Si FET decreased as the ratio of the adenine-thymine (AT) pair decreased, and the ratio of the GC pair and AT pair was controlled by the total number of the base pair. In addition, it was found that the hole conduction mechanism of the 400 bp DNA/Si FET was polaron hopping and its activation energy was 0.13eV. By considering the electron affinity of the adenine, thymine, guanine, and cytosine, the ambipolar characteristics of the DNA/Si FET was understood. The holes are injected to the guanine base for the negative gate voltage, and the electrons are injected to the adenine, thymine, and cytosine for the positive gate voltage.

  • Locally Differentially Private Minimum Finding

    Kazuto FUKUCHI  Chia-Mu YU  Jun SAKUMA  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2022/05/11
      Vol:
    E105-D No:8
      Page(s):
    1418-1430

    We investigate a problem of finding the minimum, in which each user has a real value, and we want to estimate the minimum of these values under the local differential privacy constraint. We reveal that this problem is fundamentally difficult, and we cannot construct a consistent mechanism in the worst case. Instead of considering the worst case, we aim to construct a private mechanism whose error rate is adaptive to the easiness of estimation of the minimum. As a measure of easiness, we introduce a parameter α that characterizes the fatness of the minimum-side tail of the user data distribution. As a result, we reveal that the mechanism can achieve O((ln6N/ε2N)1/2α) error without knowledge of α and the error rate is near-optimal in the sense that any mechanism incurs Ω((1/ε2N)1/2α) error. Furthermore, we demonstrate that our mechanism outperforms a naive mechanism by empirical evaluations on synthetic datasets. Also, we conducted experiments on the MovieLens dataset and a purchase history dataset and demonstrate that our algorithm achieves Õ((1/N)1/2α) error adaptively to α.

  • Label-Adversarial Jointly Trained Acoustic Word Embedding

    Zhaoqi LI  Ta LI  Qingwei ZHAO  Pengyuan ZHANG  

     
    LETTER-Speech and Hearing

      Pubricized:
    2022/05/20
      Vol:
    E105-D No:8
      Page(s):
    1501-1505

    Query-by-example spoken term detection (QbE-STD) is a task of using speech queries to match utterances, and the acoustic word embedding (AWE) method of generating fixed-length representations for speech segments has shown high performance and efficiency in recent work. We propose an AWE training method using a label-adversarial network to reduce the interference information learned during AWE training. Experiments demonstrate that our method achieves significant improvements on multilingual and zero-resource test sets.

  • A Low-Cost Training Method of ReRAM Inference Accelerator Chips for Binarized Neural Networks to Recover Accuracy Degradation due to Statistical Variabilities

    Zian CHEN  Takashi OHSAWA  

     
    PAPER-Integrated Electronics

      Pubricized:
    2022/01/31
      Vol:
    E105-C No:8
      Page(s):
    375-384

    A new software based in-situ training (SBIST) method to achieve high accuracies is proposed for binarized neural networks inference accelerator chips in which measured offsets in sense amplifiers (activation binarizers) are transformed into biases in the training software. To expedite this individual training, the initial values for the weights are taken from results of a common forming training process which is conducted in advance by using the offset fluctuation distribution averaged over the fabrication line. SPICE simulation inference results for the accelerator predict that the accuracy recovers to higher than 90% even when the amplifier offset is as large as 40mV only after a few epochs of the individual training.

  • Experimental Extraction Method for Primary and Secondary Parameters of Shielded-Flexible Printed Circuits

    Taiki YAMAGIWA  Yoshiki KAYANO  Yoshio KAMI  Fengchao XIAO  

     
    PAPER-Electromagnetic Compatibility(EMC)

      Pubricized:
    2022/02/28
      Vol:
    E105-B No:8
      Page(s):
    913-922

    In this paper, an experimental method is proposed for extracting the primary and secondary parameters of transmission lines with frequency dispersion. So far, there is no report of these methods being applied to transmission lines with frequency dispersion. This paper provides an experimental evaluation means of transmission lines with frequency dispersion and clarifies the issues when applying the proposed method. In the proposed experimental method, unnecessary components such as connectors are removed by using a simple de-embedding method. The frequency response of the primary and secondary parameters extracted by using the method reproduced all dispersion characteristics of a transmission line with frequency dispersion successfully. It is demonstrated that an accurate RLGC equivalent-circuit model is obtained experimentally, which can be used to quantitatively evaluate the frequency/time responses of shielded-FPC with frequency dispersion and to validate RLGC equivalent-circuit models extracted by using electromagnetic field analysis.

  • Deep Learning Based Low Complexity Symbol Detection and Modulation Classification Detector

    Chongzheng HAO  Xiaoyu DANG  Sai LI  Chenghua WANG  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2022/01/24
      Vol:
    E105-B No:8
      Page(s):
    923-930

    This paper presents a deep neural network (DNN) based symbol detection and modulation classification detector (SDMCD) for mixed blind signals detection. Unlike conventional methods that employ symbol detection after modulation classification, the proposed SDMCD can perform symbol recovery and modulation identification simultaneously. A cumulant and moment feature vector is presented in conjunction with a low complexity sparse autoencoder architecture to complete mixed signals detection. Numerical results show that SDMCD scheme has remarkable symbol error rate performance and modulation classification accuracy for various modulation formats in AWGN and Rayleigh fading channels. Furthermore, the proposed detector has robust performance under the impact of frequency and phase offsets.

801-820hit(22683hit)