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1221-1240hit(42807hit)

  • A Low Power 100-Gb/s PAM-4 Driver with Linear Distortion Compensation in 65-nm CMOS

    Xiangyu MENG  Kangfeng WEI  Zhiyi YU  Xinlun CAI  

     
    PAPER-Electronic Circuits

      Pubricized:
    2022/07/01
      Vol:
    E106-C No:1
      Page(s):
    7-13

    This paper proposes a low-power 100Gb/s four-level pulse amplitude modulation driver (PAM-4 Driver) based on linear distortion compensation structure for thin-film Lithium Niobate (LiNbO3) modulators, which manages to achieve high linearity in the output. The inductive peaking technology and open drain structure enable the overall circuit to achieve a 31-GHz bandwidth. With an area of 0.292 mm2, the proposed PAM-4 driver chip is designed in a 65-nm process to achieve power consumption of 37.7 mW. Post-layout simulation results show that the power efficiency is 0.37 mW/Gb/s, RLM is more than 96%, and the FOM value is 8.84.

  • A Low-Latency 4K HEVC Multi-Channel Encoding System with Content-Aware Bitrate Control for Live Streaming

    Daisuke KOBAYASHI  Ken NAKAMURA  Masaki KITAHARA  Tatsuya OSAWA  Yuya OMORI  Takayuki ONISHI  Hiroe IWASAKI  

     
    PAPER-Image Processing and Video Processing

      Pubricized:
    2022/09/30
      Vol:
    E106-D No:1
      Page(s):
    46-57

    This paper describes a novel low-latency 4K 60 fps HEVC (high efficiency video coding)/H.265 multi-channel encoding system with content-aware bitrate control for live streaming. Adaptive bitrate (ABR) streaming techniques, such as MPEG-DASH (dynamic adaptive streaming over HTTP) and HLS (HTTP live streaming), spread widely on Internet video streaming. Live content has increased with the expansion of streaming services, which has led to demands for traffic reduction and low latency. To reduce network traffic, we propose content-aware dynamic and seamless bitrate control that supports multi-channel real-time encoding for ABR, including 4K 60 fps video. Our method further supports chunked packaging transfer to provide low-latency streaming. We adopt a hybrid architecture consisting of hardware and software processing. The system consists of multiple 4K HEVC encoder LSIs that each LSI can encode 4K 60 fps or up to high-definition (HD) ×4 videos efficiently with the proposed bitrate control method. The software takes the packaging process according to the various streaming protocol. Experimental results indicate that our method reduces encoding bitrates obtained with constant bitrate encoding by as much as 56.7%, and the streaming latency over MPEG-DASH is 1.77 seconds.

  • Auxiliary Loss for BERT-Based Paragraph Segmentation

    Binggang ZHUO  Masaki MURATA  Qing MA  

     
    PAPER-Natural Language Processing

      Pubricized:
    2022/10/20
      Vol:
    E106-D No:1
      Page(s):
    58-67

    Paragraph segmentation is a text segmentation task. Iikura et al. achieved excellent results on paragraph segmentation by introducing focal loss to Bidirectional Encoder Representations from Transformers. In this study, we investigated paragraph segmentation on Daily News and Novel datasets. Based on the approach proposed by Iikura et al., we used auxiliary loss to train the model to improve paragraph segmentation performance. Consequently, the average F1-score obtained by the approach of Iikura et al. was 0.6704 on the Daily News dataset, whereas that of our approach was 0.6801. Our approach thus improved the performance by approximately 1%. The performance improvement was also confirmed on the Novel dataset. Furthermore, the results of two-tailed paired t-tests indicated that there was a statistical significance between the performance of the two approaches.

  • Entropy Regularized Unsupervised Clustering Based on Maximum Correntropy Criterion and Adaptive Neighbors

    Xinyu LI  Hui FAN  Jinglei LIU  

     
    LETTER-Artificial Intelligence, Data Mining

      Pubricized:
    2022/10/06
      Vol:
    E106-D No:1
      Page(s):
    82-85

    Constructing accurate similarity graph is an important process in graph-based clustering. However, traditional methods have three drawbacks, such as the inaccuracy of the similarity graph, the vulnerability to noise and outliers, and the need for additional discretization process. In order to eliminate these limitations, an entropy regularized unsupervised clustering based on maximum correntropy criterion and adaptive neighbors (ERMCC) is proposed. 1) Combining information entropy and adaptive neighbors to solve the trivial similarity distributions. And we introduce l0-norm and spectral embedding to construct similarity graph with sparsity and strong segmentation ability. 2) Reducing the negative impact of non-Gaussian noise by reconstructing the error using correntropy. 3) The prediction label vector is directly obtained by calculating the sparse strongly connected components of the similarity graph Z, which avoids additional discretization process. Experiments are conducted on six typical datasets and the results showed the effectiveness of the method.

  • Skin Visualization Using Smartphone and Deep Learning in the Beauty Industry

    Makoto HASEGAWA  Rui MATSUO  

     
    PAPER-Biocybernetics, Neurocomputing

      Pubricized:
    2022/10/12
      Vol:
    E106-D No:1
      Page(s):
    68-77

    Human skin visualization in the beauty industry with a smart-phone based on deep learning was discussed. Skin was photographed with a medical camera that could simultaneously capture RGB and UV images of the same area. Smartphone RGB images were converted into versions similar to medical RGB and UV images via a deep learning method called cycle-GAN, which was trained with the medical and the smartphone images. After converting the smartphone image into a version similar to a medical RGB image using cycle-GAN, the processed image was also converted into a pseudo-UV image via a deep learning method called U-NET. Hidden age spots were effectively visualized by this image. RGB and UV images similar to medical images can be captured with a smartphone. Provided the neural network on deep learning is trained, a medical camera is not required.

  • Robust Optimization Model for Primary and Backup Capacity Allocations against Multiple Physical Machine Failures under Uncertain Demands in Cloud

    Mitsuki ITO  Fujun HE  Kento YOKOUCHI  Eiji OKI  

     
    PAPER-Network

      Pubricized:
    2022/07/05
      Vol:
    E106-B No:1
      Page(s):
    18-34

    This paper proposes a robust optimization model for probabilistic protection under uncertain capacity demands to minimize the total required capacity against multiple simultaneous failures of physical machines. The proposed model determines both primary and backup virtual machine allocations simultaneously under the probabilistic protection guarantee. To express the uncertainty of capacity demands, we introduce an uncertainty set that considers the upper bound of the total demand and the upper and lower bounds of each demand. The robust optimization technique is applied to the optimization model to deal with two uncertainties: failure event and capacity demand. With this technique, the model is formulated as a mixed integer linear programming (MILP) problem. To solve larger sized problems, a simulated annealing (SA) heuristic is introduced. In SA, we obtain the capacity demands by solving maximum flow problems. Numerical results show that our proposed model reduces the total required capacity compared with the conventional model by determining both primary and backup virtual machine allocations simultaneously. We also compare the results of MILP, SA, and a baseline greedy algorithm. For a larger sized problem, we obtain approximate solutions in a practical time by using SA and the greedy algorithm.

  • A Low Insertion Loss Wideband Bonding-Wire Based Interconnection for 400 Gbps PAM4 Transceivers

    Xiangyu MENG  Yecong LI  Zhiyi YU  

     
    PAPER-Electronic Components

      Pubricized:
    2022/06/23
      Vol:
    E106-C No:1
      Page(s):
    14-19

    This paper proposes a design of high-speed interconnection between optical modules and electrical modules via bonding-wires and coplanar waveguide transmission lines on printed circuit boards for 400 Gbps 4-channel optical communication systems. In order to broaden the interconnection bandwidth, interdigitated capacitors were integrated with GSG pads on chip for the first time. Simulation results indicate the reflection coefficient is below -10 dB from DC to 53 GHz and the insertion loss is below 1 dB from DC to 45 GHz. Both indicators show that the proposed interconnection structure can effectively satisfy the communication bandwidth requirements of 100-Gbps or even higher data-rate PAM4 signals.

  • Intelligent Dynamic Channel Assignment with Small-Cells for Uplink Machine-Type Communications

    Se-Jin KIM  

     
    LETTER-Mobile Information Network and Personal Communications

      Pubricized:
    2022/06/27
      Vol:
    E106-A No:1
      Page(s):
    88-91

    This letter proposes a novel intelligent dynamic channel assignment (DCA) scheme with small-cells to improve the system performance for uplink machine-type communications (MTC) based on OFDMA-FDD. Outdoor MTC devices (OMDs) have serious interference from indoor MTC devices (IMDs) served by small-cell access points (SAPs) with frequency reuse. Thus, in the proposed DCA scheme, the macro base station (MBS) first measures the received signal strength from both OMDs and IMDs after setting the transmission power. Then, the MBS dynamically assigns subchannels to each SAP with consideration of strong interference from IMDs to the MBS. Through simulation results, it is shown that the proposed DCA scheme outperforms other schemes in terms of the capacity of OMDs and IMDs.

  • Optimal Positioning Scheme of Multiple UAVs through DOP Minimization for Location Identification of Unknown Radar

    Jisoo KIM  Seonjoo CHOI  Jaesung LIM  

     
    LETTER-Fundamentals of Information Systems

      Pubricized:
    2022/09/30
      Vol:
    E106-D No:1
      Page(s):
    78-81

    In time difference of arrival-based signal source location estimation, geometrical errors are caused by the location of multiple unmanned aerial vehicles (UAV). Herein, we propose a divide-and-conquer algorithm to determine the optimal location for each UAV. Simulations results confirm that multiple UAVs shifted to an optimal position and the location accuracy improved.

  • Verikube: Automatic and Efficient Verification for Container Network Policies

    Haney KANG  Seungwon SHIN  

     
    LETTER-Information Network

      Pubricized:
    2022/08/26
      Vol:
    E105-D No:12
      Page(s):
    2131-2134

    Recently, Linux Container has been the de-facto standard for a cloud system, enabling cloud providers to create a virtual environment in a much more scaled manner. However, configuring container networks remains immature and requires automatic verification for efficient cloud management. We propose Verikube, which utilizes a novel graph structure representing policies to reduce memory consumption and accelerate verification. Moreover, unlike existing works, Verikube is compatible with the complex semantics of Cilium Policy which a cloud adopts from its advantage of performance. Our evaluation results show that Verikube performs at least seven times better for memory efficiency, at least 1.5 times faster for data structure management, and 20K times better for verification.

  • A Novel Hierarchical V2V Routing Algorithm Based on Bus in Urban VANETs

    Xiang BI  Shengzhen YANG  Benhong ZHANG  Xing WEI  

     
    PAPER-Network

      Pubricized:
    2022/05/19
      Vol:
    E105-B No:12
      Page(s):
    1487-1497

    Multi-hop V2V communication is a fundamental way to realize data transmission in Vehicular Ad-hoc Networks (VANET). It has excellent potential in intelligent transportation systems and automatic vehicle driving, and positively affects the safety, reliability, and comfort of vehicles. With advantages in speed and trajectory, distribution along the route, size, etc., the urban buses have become prospective relay nodes for urban VANETs. However, it is a considerable challenge to construct stable and reliable (meeting the requirements of bandwidth, delay, and bit error rate) multi-hop routing because of the complexity of the urban road and bus line network in the communication area, as well as many unevenly distributed buses on the road, etc. Given this above, this paper proposes a new hierarchical routing algorithm based on V2V geographic topology segmentation. Urban hierarchical routing is divided into two layers. The first layer of routing is called coarse routing, which is composed of areas; the second layer of routing is called internal routing (bus routing within the area). Q-learning is used to formulate the sequence of buses that transmit information within each area. Details are as follows: Firstly, based on a city map containing road network information, the entire city is divided into small grids by physical streets. Secondly, based on an analysis of the characteristics of the adjacent grid bus lines, the grids with the same routing attributes are integrated into the same area, reducing the algorithm's computational complexity during route discovery. Then, for the calculated area set, a coarse route composed of the selected area is established by filtering out a group of areas satisfying from the source node to the destination node. Finally, the bus sequence between anchor intersections is selected within the chosen area, and a complete multi-hop route from the source node to the destination node is finally constructed. Sufficient simulations show that the proposed routing algorithm has more stable performance in terms of packet transmission rate, average end-to-end delay, routing duration, and other indicators than similar algorithms.

  • A Novel e-Cash Payment System with Divisibility Based on Proxy Blind Signature in Web of Things

    Iuon-Chang LIN  Chin-Chen CHANG  Hsiao-Chi CHIANG  

     
    PAPER-Information Network

      Pubricized:
    2022/09/02
      Vol:
    E105-D No:12
      Page(s):
    2092-2103

    The prosperous Internet communication technologies have led to e-commerce in mobile computing and made Web of Things become popular. Electronic payment is the most important part of e-commerce, so many electronic payment schemes have been proposed. However, most of proposed schemes cannot give change. Based on proxy blind signatures, an e-cash payment system is proposed in this paper to solve this problem. This system can not only provide change divisibility through Web of Things, but also provide anonymity, verifiability, unforgeability and double-spending owner track.

  • Faster Key Generation of Supersingular Isogeny Diffie-Hellman

    Kaizhan LIN  Fangguo ZHANG  Chang-An ZHAO  

     
    PAPER-Cryptography and Information Security

      Pubricized:
    2022/05/30
      Vol:
    E105-A No:12
      Page(s):
    1551-1558

    Supersingular isogeny Diffie-Hellman (SIDH) is attractive for its relatively small public key size, but it is still unsatisfactory due to its efficiency, compared to other post-quantum proposals. In this paper, we focus on the performance of SIDH when the starting curve is E6 : y2 = x3 + 6x2 + x, which is fixed in Round-3 SIKE implementation. Inspired by previous works [1], [2], we present several tricks to accelerate key generation of SIDH and each process of SIKE. Our experimental results show that the performance of this work is at least 6.09% faster than that of the SIKE implementation, and we can further improve the performance when large storage is available.

  • Comparison of Value- and Reference-Based Memory Page Compaction in Virtualized Systems

    Naoki AOYAMA  Hiroshi YAMADA  

     
    PAPER-Software System

      Pubricized:
    2022/08/31
      Vol:
    E105-D No:12
      Page(s):
    2075-2084

    The issue of copying values or references has historically been studied for managing memory objects, especially in distributed systems. In this paper, we explore a new topic on copying values v.s. references, for memory page compaction on virtualized systems. Memory page compaction moves target physical pages to a contiguous memory region at the operating system kernel level to create huge pages. Memory virtualization provides an opportunity to perform memory page compaction by copying the references of the physical pages. That is, instead of copying pages' values, we can move guest physical pages by changing the mappings of guest-physical to machine-physical pages. The goal of this paper is a quantitative comparison between value- and reference-based memory page compaction. To do so, we developed a software mechanism that achieves memory page compaction by appropriately updating the references of guest-physical pages. We prototyped the mechanism on Linux 4.19.29 and the experimental results show that the prototype's page compaction is up to 78% faster and achieves up to 17% higher performance on the memory-intensive real-world applications as compared to the default value-copy compaction scheme.

  • A Direct Construction of Binary Even-Length Z-Complementary Pairs with Zero Correlation Zone Ratio of 6/7

    Xiuping PENG  Mingshuo SHEN  Hongbin LIN  Shide WANG  

     
    LETTER-Digital Signal Processing

      Pubricized:
    2022/05/26
      Vol:
    E105-A No:12
      Page(s):
    1612-1615

    This letter provides a direct construction of binary even-length Z-complementary pairs. To date, the maximum zero correlation zone ratio of Type-I Z-complementary pairs has reached 6/7, but no direct construction of Z-complementary pairs can achieve the zero correlation zone ratio of 6/7. In this letter, based on Boolean function, we give a direct construction of binary even-length Z-complementary pairs with zero correlation zone ratio 6/7. The length of constructed Z-complementary pairs is 2m+3 + 2m + 2+2m+1 and the width of zero correlation zone is 2m+3 + 2m+2.

  • Ground Test of Radio Frequency Compatibility for Cn-Band Satellite Navigation and Microwave Landing System Open Access

    Ruihua LIU  Yin LI  Ling ZOU  Yude NI  

     
    PAPER-Satellite Communications

      Pubricized:
    2022/05/19
      Vol:
    E105-B No:12
      Page(s):
    1580-1588

    Testing the radio frequency compatibility between Cn-band Satellite Navigation and Microwave Landing System (MLS) has included establishing a specific interference model and reporting the effect of such interference. This paper considers two interference scenarios according to the interfered system. By calculating the Power Flux Density (PFD) values, the interference for Cn-band satellite navigation downlink signal from several visible space stations on MLS service is evaluated. Simulation analysis of the interference for MLS DPSK-data word signal and scanning signal on Cn-band satellite navigation signal is based on the Spectral Separation Coefficient (SSC) and equivalent Carrier-to-Noise Ratio methodologies. Ground tests at a particular military airfield equipped with MLS ground stations were successfully carried out, and some measured data verified the theoretical and numerical results. This study will certainly benefit the design of Cn-band satellite navigation signals and guide the interoperability and compatibility research of Cn-band satellite navigation and MLS.

  • Accurate Parallel Flow Monitoring for Loss Measurements

    Kohei WATABE  Norinosuke MURAI  Shintaro HIRAKAWA  Kenji NAKAGAWA  

     
    PAPER-Network Management/Operation

      Pubricized:
    2022/06/29
      Vol:
    E105-B No:12
      Page(s):
    1530-1539

    End-to-end loss and delay are both fundamental metrics in network performance evaluation, and accurate measurements for these end-to-end metrics are one of the keys to keeping delay/loss-sensitive applications (e.g., audio/video conferencing, IP telephony, or telesurgery) comfortable on networks. In our previous work [1], we proposed a parallel flow monitoring method that can provide accurate active measurements of end-to-end delay. In this method, delay samples of a target flow increase by utilizing the observation results of other flows sharing the source/destination with the target flow. In this paper, to improve accuracy of loss measurements, we propose a loss measurement method by extending our delay measurement method. Additionally, we improve the loss measurement method so that it enables to fully utilize information of all flows including flows with different source and destination. We evaluate the proposed method through theoretical and simulation analyses. The evaluations show that the accuracy of the proposed method is bounded by theoretical upper/lower bounds, and it is confirmed that it reduces the error of loss rate estimations by 57.5% on average.

  • The Implementation of a Hybrid Router and Dynamic Switching Algorithm on a Multi-FPGA System

    Tomoki SHIMIZU  Kohei ITO  Kensuke IIZUKA  Kazuei HIRONAKA  Hideharu AMANO  

     
    PAPER

      Pubricized:
    2022/06/30
      Vol:
    E105-D No:12
      Page(s):
    2008-2018

    The multi-FPGA system known as, the Flow-in-Cloud (FiC) system, is composed of mid-range FPGAs that are directly interconnected by high-speed serial links. FiC is currently being developed as a server for multi-access edge computing (MEC), which is one of the core technologies of 5G. Because the applications of MEC are sometimes timing-critical, a static time division multiplexing (STDM) network has been used on FiC. However, the STDM network exhibits the disadvantage of decreasing link utilization, especially under light traffic. To solve this problem, we propose a hybrid router that combines packet switching for low-priority communication and STDM for high-priority communication. In our hybrid network, the packet switching uses slots that are unused by the STDM; therefore, best-effort communication by packet switching and QoS guarantee communication by the STDM can be used simultaneously. Furthermore, to improve each link utilization under a low network traffic load, we propose a dynamic communication switching algorithm. In our algorithm, each router monitors the network load metrics, and according to the metrics, timing-critical tasks select the STDM according to the metrics only when congestion occurs. This can achieve both QoS guarantee and efficient utilization of each link with a small resource overhead. In our evaluation, the dynamic algorithm was up to 24.6% faster on the execution time with a high network load compared to the packet switching on a real multi-FPGA system with 24 boards.

  • FOREWORD Open Access

    Toshihiro YAMAUCHI  

     
    FOREWORD

      Vol:
    E105-D No:12
      Page(s):
    1998-1998
  • New Restricted Isometry Condition Using Null Space Constant for Compressed Sensing

    Haiyang ZOU  Wengang ZHAO  

     
    PAPER-Information Theory

      Pubricized:
    2022/06/20
      Vol:
    E105-A No:12
      Page(s):
    1591-1603

    It has been widely recognized that in compressed sensing, many restricted isometry property (RIP) conditions can be easily obtained by using the null space property (NSP) with its null space constant (NSC) 0<θ≤1 to construct a contradicted method for sparse signal recovery. However, the traditional NSP with θ=1 will lead to conservative RIP conditions. In this paper, we extend the NSP with 0<θ<1 to a scale NSP, which uses a factor τ to scale down all vectors belonged to the Null space of a sensing matrix. Following the popular proof procedure and using the scale NSP, we establish more relaxed RIP conditions with the scale factor τ, which guarantee the bounded approximation recovery of all sparse signals in the bounded noisy through the constrained l1 minimization. An application verifies the advantages of the scale factor in the number of measurements.

1221-1240hit(42807hit)