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1101-1120hit(18690hit)

  • Complete l-Diversity Grouping Algorithm for Multiple Sensitive Attributes and Its Applications

    Yuelei XIAO  Shuang HUANG  

     
    LETTER-Cryptography and Information Security

      Pubricized:
    2021/01/12
      Vol:
    E104-A No:7
      Page(s):
    984-990

    For the first stage of the multi-sensitive bucketization (MSB) method, the l-diversity grouping for multiple sensitive attributes is incomplete, causing more information loss. To solve this problem, we give the definitions of the l-diversity avoidance set for multiple sensitive attributes and the avoiding of a multiple dimensional bucket, and propose a complete l-diversity grouping (CLDG) algorithm for multiple sensitive attributes. Then, we improve the first stages of the MSB algorithms by applying the CLDG algorithm to them. The experimental results show that the grouping ratio of the improved first stages of the MSB algorithms is significantly higher than that of the original first stages of the MSB algorithms, decreasing the information loss of the published microdata.

  • A Global Deep Reranking Model for Semantic Role Classification

    Haitong YANG  Guangyou ZHOU  Tingting HE  Maoxi LI  

     
    LETTER-Natural Language Processing

      Pubricized:
    2021/04/15
      Vol:
    E104-D No:7
      Page(s):
    1063-1066

    The current approaches to semantic role classification usually first define a representation vector for a candidate role and feed the vector into a deep neural network to perform classification. The representation vector contains some lexicalization features like word embeddings, lemmar embeddings. From linguistics, the semantic role frame of a sentence is a joint structure with strong dependencies between arguments which is not considered in current deep SRL systems. Therefore, this paper proposes a global deep reranking model to exploit these strong dependencies. The evaluation experiments on the CoNLL 2009 shared tasks show that our system can outperforms a strong local system significantly that does not consider role dependency relations.

  • Low-Power Implementation Techniques for Convolutional Neural Networks Using Precise and Active Skipping Methods Open Access

    Akira KITAYAMA  Goichi ONO  Tadashi KISHIMOTO  Hiroaki ITO  Naohiro KOHMU  

     
    PAPER

      Pubricized:
    2020/12/22
      Vol:
    E104-C No:7
      Page(s):
    330-337

    Reducing power consumption is crucial for edge devices using convolutional neural network (CNN). The zero-skipping approach for CNNs is a processing technique widely known for its relatively low power consumption and high speed. This approach stops multiplication and accumulation (MAC) when the multiplication results of the input data and weight are zero. However, this technique requires large logic circuits with around 5% overhead, and the average rate of MAC stopping is approximately 30%. In this paper, we propose a precise zero-skipping method that uses input data and simple logic circuits to stop multipliers and accumulators precisely. We also propose an active data-skipping method to further reduce power consumption by slightly degrading recognition accuracy. In this method, each multiplier and accumulator are stopped by using small values (e.g., 1, 2) as input. We implemented single shot multi-box detector 500 (SSD500) network model on a Xilinx ZU9 and applied our proposed techniques. We verified that operations were stopped at a rate of 49.1%, recognition accuracy was degraded by 0.29%, power consumption was reduced from 9.2 to 4.4 W (-52.3%), and circuit overhead was reduced from 5.1 to 2.7% (-45.9%). The proposed techniques were determined to be effective for lowering the power consumption of CNN-based edge devices such as FPGA.

  • Multi-View Texture Learning for Face Super-Resolution

    Yu WANG  Tao LU  Feng YAO  Yuntao WU  Yanduo ZHANG  

     
    PAPER-Image Recognition, Computer Vision

      Pubricized:
    2021/03/24
      Vol:
    E104-D No:7
      Page(s):
    1028-1038

    In recent years, single face image super-resolution (SR) using deep neural networks have been well developed. However, most of the face images captured by the camera in a real scene are from different views of the same person, and the existing traditional multi-frame image SR requires alignment between images. Due to multi-view face images contain texture information from different views, which can be used as effective prior information, how to use this prior information from multi-views to reconstruct frontal face images is challenging. In order to effectively solve the above problems, we propose a novel face SR network based on multi-view face images, which focus on obtaining more texture information from multi-view face images to help the reconstruction of frontal face images. And in this network, we also propose a texture attention mechanism to transfer high-precision texture compensation information to the frontal face image to obtain better visual effects. We conduct subjective and objective evaluations, and the experimental results show the great potential of using multi-view face images SR. The comparison with other state-of-the-art deep learning SR methods proves that the proposed method has excellent performance.

  • A CMOS SPDT RF Switch with 68dB Isolation and 1.0dB Loss Feathering Switched Resonance Network for MIMO Applications

    Xi FU  Yun WANG  Zheng LI  Atsushi SHIRANE  Kenichi OKADA  

     
    PAPER

      Pubricized:
    2021/01/08
      Vol:
    E104-C No:7
      Page(s):
    280-288

    There are enlarged requirements of millimeter-wave beamforming phased-array transceivers and high-order modulation multi-input multi-output (MIMO) transceivers. High-performance integrated RF switches are regarded as one of the most critical components for those transceivers to support signal channel distribution and path redundancy. This paper introduces a CMOS high-isolation and low-loss RF switch with a novel switched parallel LC resonance network. The proposed single-pole double-throw (SPDT) RF switch realizes 68dB port isolation and 1.0dB insertion loss with an active area of 0.034mm2. The SPDT RF switch is composed of two series-shunt transistor pairs with body-floating technology and a switched parallel LC network. The network uses a turned-off series transistor to resonate out off-capacitance Coff. The measured output third-order intercept (OIP3) is higher than 21dBm. The proposed SPDT RF switch maintains return losses of all working ports less than 10dB from 8GHz to 20GHz. The high-performance SPDT RF switch is fabricated in standard 65-nm CMOS technology.

  • Extension of ITU-R Site-General Path Loss Model in Urban Areas Based on Measurements from 2 to 66GHz Bands Open Access

    Motoharu SASAKI  Mitsuki NAKAMURA  Nobuaki KUNO  Wataru YAMADA  Naoki KITA  Takeshi ONIZAWA  Yasushi TAKATORI  Hiroyuki NAKAMURA  Minoru INOMATA  Koshiro KITAO  Tetsuro IMAI  

     
    PAPER-Antennas and Propagation

      Pubricized:
    2021/01/08
      Vol:
    E104-B No:7
      Page(s):
    849-857

    Path loss in high frequency bands above 6GHz is the most fundamental and significant propagation characteristic of IMT-2020. To develop and evaluate such high frequency bands, ITU-R SG5 WP5D recently released channel models applicable up to 100GHz. The channel models include path loss models applicable to 0.5-100GHz. A path loss model is used for cell design and the evaluation of the radio technologies, which is the main purpose of WP5D. Prediction accuracy in various locations, Tx positions, frequency bands, and other parameters are significant in cell design. This article presents the prediction accuracy of UMa path loss models which are detailed in Report ITU-R M.2412 for IMT-2020. We also propose UMa_A' as an extension model of UMa_A. While UMa_A applies different equations to the bands below and above 6GHz to predict path loss, UMa_A' covers all bands by using the equations of UMa_A below 6GHz. By using the UMa_A' model, we can predict path loss by taking various parameters (such as BS antenna height) into account over a wide frequency range (0.5-100GHz). This is useful for considering the deployment of BS antennas at various positions with a wide frequency band. We verify model accuracy by extensive measurements in the frequency bands from 2 to 66GHz, distances up to 1600 m, and an UMa environment with three Tx antenna heights. The UMa_A' extension model can predict path loss with the low RMSE of about 7dB at 2-26.4GHz, which is more accurate than the UMa_A and UMa_B models. Although the applicability of the UMa_A' model at 66GHz is unclear and needs further verification, the evaluation results for 66GHz demonstrate that the antenna height may affect the prediction accuracy at 66GHz.

  • Coherent Signal DOA Estimation Using Eigenvector Associated with Max Eigenvalue

    Rui LI  Ruqi XIAO  Hong GU  Weimin SU  

     
    PAPER-Digital Signal Processing

      Pubricized:
    2021/01/07
      Vol:
    E104-A No:7
      Page(s):
    962-967

    A novel direction of arrival (DOA) estimation method for the coherent signal is presented in this paper. The proposed method applies the eigenvector associated with max eigenvalue, which contains the DOAs of all signals, to form a Toeplitz matrix, yielding an unconstrained optimization problem. Then, the DOA is obtained by peak searching of the pseudo power spectrum without the knowledge of signal number. It is illustrated that the method has a great performance and low computation complexity for the coherent signal. Simulation results verify the usefulness of the method.

  • Encrypted Traffic Categorization Based on Flow Byte Sequence Convolution Aggregation Network

    Lin YAN  Mingyong ZENG  Shuai REN  Zhangkai LUO  

     
    LETTER-Mobile Information Network and Personal Communications

      Pubricized:
    2020/12/24
      Vol:
    E104-A No:7
      Page(s):
    996-999

    Traffic categorization aims to classify network traffic into major service types. A modern deep neural network based on temporal sequence modeling is proposed for encrypted traffic categorization. The contemporary techniques such as dilated convolution and residual connection are adopted as the basic building block. The raw traffic files are pre-processed to generate 1-dimensional flow byte sequences and are feed into our specially-devised network. The proposed approach outperforms other existing methods greatly on a public traffic dataset.

  • Color Conversion Formula with Saturation Correction from HSI Color Space to RGB Color Space

    Minako KAMIYAMA  Akira TAGUCHI  

     
    LETTER-Image

      Pubricized:
    2021/01/18
      Vol:
    E104-A No:7
      Page(s):
    1000-1005

    In color image processing, preservation of hue is required. Therefore, perceptual color models such as HSI and HSV have been used. Hue-Saturation-Intensity (HSI) is a public color model, and many color applications have been made based on this model. However, the transformation from the conventional HSI (C-HSI) color space to the RGB color space after processing intensity/saturation in the C-HSI color space often generates the gamut problem, because the shape of C-HSI color space is a triangular pyramid which includes the RGB color space. When the output of intensity/saturation processing result is located in the outside of the common region of RGB color space and C-HSI color space, it is necessary to move to the RGB color space. The effective way of hue and intensity preserving saturation correction algorithm is proposed. According to the proposed saturation correction algorithm, the corrected saturation value is same as the processing result in the ideal HSI color space whose gamut same as the RGB gamut.

  • Derivation Procedure of Coefficients of Metadata-Based Model for Adaptive Bitrate Streaming Services Open Access

    Kazuhisa YAMAGISHI  Noritsugu EGI  Noriko YOSHIMURA  Pierre LEBRETON  

     
    PAPER

      Pubricized:
    2021/01/08
      Vol:
    E104-B No:7
      Page(s):
    725-737

    Since the quality of video streaming services is degraded due to the encoding, network congestion, and lack of a playout buffer, the normality of services needs to be monitored by gathering the quality measured at the end clients. When measuring quality at the end clients, the computational power should be sufficiently low, the bitstream information cannot be accessed for the quality estimation due to the encryption, and reference video cannot be used at the end clients. Therefore, metadata-based models have been developed and standardized that take metadata such as the resolution, framerate, and bitrate, and stalling information as input and calculate the quality. However, calculated quality for linear TV and video on demand (VoD) services cannot be compared because metadata-based models cannot calculate the impacts of codec strategies (e.g., H.264/AVC, H.265/HEVC, and AV1) and configurations (e.g., 1-pass encoding for linear TV or 2-pass encoding for VoD) on the quality. To take into account the impact of codec strategies and configurations, coefficients of metadata-based model need to be optimized per codec strategy and configuration using subjective quality. However, extensive subjective assessment tests are difficult to frequently conduct because they are expensive and time consuming and need to be conducted by video quality experts. Therefore, to monitor the quality of several types of video streaming services (e.g., linear TV and VoD) and to compare these qualities, a derivation procedure is proposed for obtaining coefficients of metadata-based models using a full-reference model. To validate the procedure, extensive subjective assessment tests were conducted. Finally, it is shown that three metadata-based models (i.e., the P.1203.1 mode 0 model, extended P.1203.1 mode 0 model, and model proposed by Yamagishi et al.) based on the proposed procedure using the video multimethod assessment fusion (VMAF) algorithm estimate quality accurately in terms of root mean squared error.

  • Routing and Capacity Optimization Based on Estimated Latent OD Traffic Demand

    Takumi UCHIDA  Keisuke ISHIBASHI  Kensuke FUKUDA  

     
    PAPER

      Pubricized:
    2021/01/29
      Vol:
    E104-B No:7
      Page(s):
    781-790

    This paper introduces a method to estimate latent traffic from its origin to destination from the link packet loss rate and traffic volume. In addition, we propose a method for the joint optimization of routing and link provisioning based on the estimated latent traffic. Observed traffic could deviate from the original traffic demand and become latent when the traffic passes through congested links because of changes in user behavioral and/or applications as a result of degraded quality of experience (QoE). The latent traffic is actualized by improving congested link capacity. When link provisioning is based on observed traffic, actual traffic might cause new congestion at other links. Thus, network providers need to estimate the origin-destination (OD) original traffic demand for network planning. Although the estimation of original traffic has been well studied, the estimation was only applicable for links. In this paper, we propose a method to estimate latent OD traffic by combining and expanding techniques. The method consists of three steps. The first step is to estimate the actual OD traffic and loss rate from the actual traffic and packet loss rate of the links. The second step is to estimate the latent traffic demand. Finally, using this estimated demand, the link capacity and routing matrix are optimized. We evaluate our method by simulation and confirm that congestion could be avoided by capacity provisioning based on estimated latent traffic, while provisioning based on observed traffic retains the congestion. The combined method can avoid congestion with an increment of 23% compared with capacity provisioning only. We also evaluated our method's adaptability, i.e., the ability to estimate the required parameter for the estimations using fewer given values, but values obtained in the environment.

  • An Intent-Based System Configuration Design for IT/NW Services with Functional and Quantitative Constraints Open Access

    Takuya KUWAHARA  Takayuki KURODA  Takao OSAKI  Kozo SATODA  

     
    PAPER

      Pubricized:
    2021/02/04
      Vol:
    E104-B No:7
      Page(s):
    791-804

    Network service providers need to appropriately design systems and carefully configuring the settings and parameters to ensure that the systems keep running consistently and deliver the desired services. This can be a heavy and error-prone task. Intent-based system design methods have been developed to help with such tasks. These methods receive service-level requirements and generate service configurations to fulfill the given requirements. One such method is search-based system design, which can flexibly generate systems of various architectures. However, it has difficulty dealing with constraints on the quantitative parameters of systems, e.g., disk volume, RAM size, and QoS. To deal with practical cases, intent-based system design engines need to be able to handle quantitative parameters and constraints. In this work, we propose a new intent-based system design method based on search-based design that augments search states with quantitative constraints. Our method can generate a system that meets both functional and quantitative service requirements by combining a search-based design method with constraint checking. Experimental results show that our method can automatically generate a system that fulfills all given requirements within a reasonable computation time.

  • Efficient Data Diffusion and Elimination Control Method for Spatio-Temporal Data Retention System Open Access

    Shumpei YAMASAKI  Daiki NOBAYASHI  Kazuya TSUKAMOTO  Takeshi IKENAGA  Myung J. LEE  

     
    PAPER

      Pubricized:
    2021/01/08
      Vol:
    E104-B No:7
      Page(s):
    805-816

    With the development and spread of Internet of Things technologies, various types of data for IoT applications can be generated anywhere and at any time. Among such data, there are data that depend heavily on generation time and location. We define these data as spatio-temporal data (STD). In previous studies, we proposed a STD retention system using vehicular networks to achieve the “Local production and consumption of STD” paradigm. The system can quickly provide STD for users within a specific location by retaining the STD within the area. However, this system does not take into account that each type of STD has different requirements for STD retention. In particular, the lifetime of STD and the diffusion time to the entire area directly influence the performance of STD retention. Therefore, we propose an efficient diffusion and elimination control method for retention based on the requirements of STD. The results of simulation evaluation demonstrated that the proposed method can satisfy the requirements of STD, while maintaining a high coverage rate in the area.

  • Heuristic Service Chain Construction Algorithm Based on VNF Performances for Optimal Data Transmission Services

    Yasuhito SUMI  Takuji TACHIBANA  

     
    PAPER

      Pubricized:
    2021/01/08
      Vol:
    E104-B No:7
      Page(s):
    817-828

    In network function virtualization (NFV) environments, service chaining is an emerging technology that enables network operators to provide network service dynamically and flexibly by using virtual network function (VNF). In the service chaining, a service chain is expected to be constructed based on VNF performances such as dependences among VNFs and traffic changing effects in VNFs. For achieving optimal data transmission services in NFV environments, we focus on the optimal service chain construction based on VNF performances so that both the maximum amount of traffic on links and the total number of VNF instances are decreased. In this paper, at first, an optimization problem is formulated for determining placements of VNFs and a route for each service chain. The service chains can be constructed by solving this optimization problem with an optimization software or meta-heuristic algorithm. Then, for the optimization problem, we propose a heuristic service chain construction algorithm. By using our proposed algorithm, the service chains can be constructed appropriately more quickly. We evaluate the performance of the proposed heuristic algorithm with simulation, and we investigate the effectiveness of the heuristic algorithm from the performance comparison. From some numerical examples, we show that the proposed heuristic algorithm is effective to decrease the amount of traffic and the number of VNF instances. Moreover, it is shown that our proposed heuristic algorithm can construct service chains quickly.

  • Effect of Failures on Stock Price of Telecommunication Service Providers

    Masahiro HAYASHI  

     
    PAPER

      Pubricized:
    2021/01/18
      Vol:
    E104-B No:7
      Page(s):
    829-836

    This paper reports the results of a new test on what types of failure cause falls in the stock prices of telecommunication service providers. This analysis of stock price is complementary to our previous one on market share. A clear result of our new test is that the type of failure causing falls in stock price is different from the type causing decline in market share. Specifically, the previous study identified frequent failures as causes of decline in market share, while the current study indicates large failures affecting many users as causes of falls in stock price. Together, these analyses give important information for reliability designs of telecommunications networks.

  • Distributed Detection of MIMO Spatial Multiplexed Signals in Terminal Collaborated Reception

    Fengning DU  Hidekazu MURATA  Mampei KASAI  Toshiro NAKAHIRA  Koichi ISHIHARA  Motoharu SASAKI  Takatsune MORIYAMA  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2020/12/29
      Vol:
    E104-B No:7
      Page(s):
    884-892

    Distributed detection techniques of multiple-input multiple-output (MIMO) spatially multiplexed signals are studied in this paper. This system considered employs multiple mobile stations (MSs) to receive signals from a base station, and then share their received signal waveforms with collaborating MSs. In order to reduce the amount of traffic over the collaborating wireless links, distributed detection techniques are proposed, in which multiple MSs are in charge of detection by making use of both the shared signal waveforms and its own received waveform. Selection combining schemes of detected bit sequences are studied to finalize the decisions. Residual error coefficients in iterative MIMO equalization and detection are utilized in this selection. The error-ratio performance is elucidated not only by computer simulations, but also by offline processing using experimental signals recorded in a measurement campaign.

  • Online Collaborative Kit-Build Concept Map: Learning Effect and Conversation Analysis in Collaborative Learning of English as a Foreign Language Reading Comprehension

    Aryo PINANDITO  Yusuke HAYASHI  Tsukasa HIRASHIMA  

     
    PAPER-Educational Technology

      Pubricized:
    2021/04/06
      Vol:
    E104-D No:7
      Page(s):
    981-991

    Concept map has been widely used as an interactive media to deliver contents in learning. Incorporating concept maps into collaborative learning could promote more interactive and meaningful learning environments. Furthermore, delivering concept maps in a digital form, such as in Kit-Build concept map, could improve learning interaction further. Collaborative learning with Kit-Build concept map has been shown to have positive effects on students' understanding. The way students compose their concept maps while discussing with others is presumed to affect their learning. However, supporting collaborative learning in an online setting is formidable to keep the interaction meaningful and fluid. This study proposed a new approach of real-time collaborative learning with Kit-Build concept map. This study also investigated how concept map recomposition with Kit-Build concept map could help students collaboratively learn EFL reading comprehension from a distance by comparing it with the traditional open-ended concept mapping approach. The learning effect and students' conversation during collaboration with the proposed online Kit-Build concept map system were investigated. Comparative analysis with a traditional collaborative concept mapping approach is also presented. The results suggested that collaborative learning with Kit-Build concept map yielded better outcomes and more meaningful discussion than the traditional open-end concept mapping.

  • Single Image Dehazing Based on Weighted Variational Regularized Model

    Hao ZHOU  Hailing XIONG  Chuan LI  Weiwei JIANG  Kezhong LU  Nian CHEN  Yun LIU  

     
    PAPER-Artificial Intelligence, Data Mining

      Pubricized:
    2021/04/06
      Vol:
    E104-D No:7
      Page(s):
    961-969

    Image dehazing is of great significance in computer vision and other fields. The performance of dehazing mainly relies on the precise computation of transmission map. However, the computation of the existing transmission map still does not work well in the sky area and is easily influenced by noise. Hence, the dark channel prior (DCP) and luminance model are used to estimate the coarse transmission in this work, which can deal with the problem of transmission estimation in the sky area. Then a novel weighted variational regularization model is proposed to refine the transmission. Specifically, the proposed model can simultaneously refine the transmittance and restore clear images, yielding a haze-free image. More importantly, the proposed model can preserve the important image details and suppress image noise in the dehazing process. In addition, a new Gaussian Adaptive Weighted function is defined to smooth the contextual areas while preserving the depth discontinuity edges. Experiments on real-world and synthetic images illustrate that our method has a rival advantage with the state-of-art algorithms in different hazy environments.

  • A Harvested Power-Oriented SWIPT Scheme in MIMO Communication Systems with Non-Linear Harvesters

    Yan CHEN  Chen LIU  Mujun QIAN  Yu HUANG  Wenfeng SUN  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2021/01/18
      Vol:
    E104-B No:7
      Page(s):
    893-902

    This paper studies a harvested power-oriented simultaneous wireless information and power transfer (SWIPT) scheme over multiple-input multiple-output (MIMO) interference channels in which energy harvesting (EH) circuits exhibit nonlinearity. To maximize the power harvested by all receivers, we propose an algorithm to jointly optimize the transmit beamforming vectors, power splitting (PS) ratios and the receive decoding vectors. As all variables are coupled to some extent, the problem is non-convex and hard to solve. To deal with this non-convex problem, an iterative optimization method is proposed. When two variables are fixed, the third variable is optimized. Specifically, when the transmit beamforming vectors are optimized, the transferred objective function is the sum of several fractional functions. Non-linear sum-of-ratios programming is used to solve the transferred objective function. The convergence and advantage of our proposed scheme compared with traditional EH circuits are validated by simulation results.

  • SLIT: An Energy-Efficient Reconfigurable Hardware Architecture for Deep Convolutional Neural Networks Open Access

    Thi Diem TRAN  Yasuhiko NAKASHIMA  

     
    PAPER

      Pubricized:
    2020/12/18
      Vol:
    E104-C No:7
      Page(s):
    319-329

    Convolutional neural networks (CNNs) have dominated a range of applications, from advanced manufacturing to autonomous cars. For energy cost-efficiency, developing low-power hardware for CNNs is a research trend. Due to the large input size, the first few convolutional layers generally consume most latency and hardware resources on hardware design. To address these challenges, this paper proposes an innovative architecture named SLIT to extract feature maps and reconstruct the first few layers on CNNs. In this reconstruction approach, total multiply-accumulate operations are eliminated on the first layers. We evaluate new topology with MNIST, CIFAR, SVHN, and ImageNet datasets on image classification application. Latency and hardware resources of the inference step are evaluated on the chip ZC7Z020-1CLG484C FPGA with Lenet-5 and VGG schemes. On the Lenet-5 scheme, our architecture reduces 39% of latency and 70% of hardware resources with a 0.456 W power consumption compared to previous works. Even though the VGG models perform with a 10% reduction in hardware resources and latency, we hope our overall results will potentially give a new impetus for future studies to reach a higher optimization on hardware design. Notably, the SLIT architecture efficiently merges with most popular CNNs at a slightly sacrificing accuracy of a factor of 0.27% on MNIST, ranging from 0.5% to 1.5% on CIFAR, approximately 2.2% on ImageNet, and remaining the same on SVHN databases.

1101-1120hit(18690hit)