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[Keyword] ERG(867hit)

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  • Joint Optimization of Task Offloading and Resource Allocation for UAV-Assisted Edge Computing: A Stackelberg Bilayer Game Approach Open Access

    Peng WANG  Guifen CHEN  Zhiyao SUN  

     
    PAPER-Information Network

      Pubricized:
    2024/05/21
      Vol:
    E107-D No:9
      Page(s):
    1174-1181

    Unmanned Aerial Vehicle (UAV)-assisted Mobile Edge Computing (MEC) can provide mobile users (MU) with additional computing services and a wide range of connectivity. This paper investigates the joint optimization strategy of task offloading and resource allocation for UAV-assisted MEC systems in complex scenarios with the goal of reducing the total system cost, consisting of task execution latency and energy consumption. We adopt a game theoretic approach to model the interaction process between the MEC server and the MU Stackelberg bilayer game model. Then, the original problem with complex multi-constraints is transformed into a duality problem using the Lagrangian duality method. Furthermore, we prove that the modeled Stackelberg bilayer game has a unique Nash equilibrium solution. In order to obtain an approximate optimal solution to the proposed problem, we propose a two-stage alternating iteration (TASR) algorithm based on the subgradient method and the marginal revenue optimization method. We evaluate the effective performance of the proposed algorithm through detailed simulation experiments. The simulation results show that the proposed algorithm is superior and robust compared to other benchmark methods and can effectively reduce the task execution latency and total system cost in different scenarios.

  • Using Genetic Algorithm and Mathematical Programming Model for Ambulance Location Problem in Emergency Medical Service Open Access

    Batnasan LUVAANJALBA  Elaine Yi-Ling WU  

     
    PAPER-Fundamentals of Information Systems

      Pubricized:
    2024/05/08
      Vol:
    E107-D No:9
      Page(s):
    1123-1132

    Emergency Medical Services (EMS) play a crucial role in healthcare systems, managing pre-hospital or out-of-hospital emergencies from the onset of an emergency call to the patient’s arrival at a healthcare facility. The design of an efficient ambulance location model is pivotal in enhancing survival rates, controlling morbidity, and preventing disability. Key factors in the classical models typically include travel time, demand zones, and the number of stations. While urban EMS systems have received extensive examination due to their centralized populations, rural areas pose distinct challenges. These include lower population density and longer response distances, contributing to a higher fatality rate due to sparse population distribution, limited EMS stations, and extended travel times. To address these challenges, we introduce a novel mathematical model that aims to optimize coverage and equity. A distinctive feature of our model is the integration of equity within the objective function, coupled with a focus on practical response time that includes the period required for personal protective equipment procedures, ensuring the model’s applicability and realism in emergency response scenarios. We tackle the proposed problem using a tailored genetic algorithm and propose a greedy algorithm for solution construction. The implementation of our tailored Genetic Algorithm promises efficient and effective EMS solutions, potentially enhancing emergency care and health outcomes in rural communities.

  • Measuring SET Pulse Widths in pMOSFETs and nMOSFETs Separately by Heavy Ion and Neutron Irradiation Open Access

    Jun FURUTA  Shotaro SUGITANI  Ryuichi NAKAJIMA  Takafumi ITO  Kazutoshi KOBAYASHI  

     
    PAPER-Semiconductor Materials and Devices

      Pubricized:
    2024/04/10
      Vol:
    E107-C No:9
      Page(s):
    255-262

    Radiation-induced temporal errors become a significant issue for circuit reliability. We measured the pulse widths of radiation-induced single event transients (SETs) from pMOSFETs and nMOSFETs separately. Test results show that heavy-ion induced SET rates of nMOSFETs were twice as high as those of pMOSFETs and that neutron-induced SETs occurred only in nMOSFETs. It was confirmed that the SET distribution from inverter chains can be estimated using the SET distribution from pMOSFETs and nMOSFETs by considering the difference in load capacitance of the measurement circuits.

  • Sum Rate Maximization for Multiuser Full-Duplex Wireless Powered Communication Networks Open Access

    Keigo HIRASHIMA  Teruyuki MIYAJIMA  

     
    PAPER-Wireless Communication Technologies

      Vol:
    E107-B No:8
      Page(s):
    564-572

    In this paper, we consider an orthogonal frequency division multiple access (OFDMA)-based multiuser full-duplex wireless powered communication network (FD WPCN) system with beamforming (BF) at an energy transmitter (ET). The ET performs BF to efficiently transmit energy to multiple users while suppressing interference to an information receiver (IR). Multiple users operating in full-duplex mode harvest energy from the signals sent by the ET while simultaneously transmitting information to the IR using the harvested energy. We analytically demonstrate that the FD WPCN is superior to its half-duplex (HD) WPCN counterpart in the high-SNR regime. We propose a transmitter design method that maximizes the sum rate by determining the BF at the ET, power allocation at both the ET and users, and sub-band allocation. Simulation results show the effectiveness of the proposed method.

  • Data-Reuse Extended NLMS Algorithm Based on Optimized Time-Varying Step-Size for System Identification Open Access

    Hakan BERCAG  Osman KUKRER  Aykut HOCANIN  

     
    LETTER-Analog Signal Processing

      Pubricized:
    2024/01/11
      Vol:
    E107-A No:8
      Page(s):
    1369-1373

    A new extended normalized least-mean-square (ENLMS) algorithm is proposed. A novel non-linear time-varying step-size (NLTVSS) formula is derived. The convergence rate of ENLMS increases due to NLTVSS as the number of data-reuse L is increased. ENLMS does not involve matrix inversion, and, thus, avoids numerical instability issues.

  • Conflict Management Method Based on a New Belief Divergence in Evidence Theory Open Access

    Zhu YIN  Xiaojian MA  Hang WANG  

     
    PAPER-Office Information Systems, e-Business Modeling

      Pubricized:
    2024/03/01
      Vol:
    E107-D No:7
      Page(s):
    857-868

    Highly conflicting evidence that may lead to the counter-intuitive results is one of the challenges for information fusion in Dempster-Shafer evidence theory. To deal with this issue, evidence conflict is investigated based on belief divergence measuring the discrepancy between evidence. In this paper, the pignistic probability transform belief χ2 divergence, named as BBχ2 divergence, is proposed. By introducing the pignistic probability transform, the proposed BBχ2 divergence can accurately quantify the difference between evidence with the consideration of multi-element sets. Compared with a few belief divergences, the novel divergence has more precision. Based on this advantageous divergence, a new multi-source information fusion method is devised. The proposed method considers both credibility weights and information volume weights to determine the overall weight of each evidence. Eventually, the proposed method is applied in target recognition and fault diagnosis, in which comparative analysis indicates that the proposed method can realize the highest accuracy for managing evidence conflict.

  • Dynamic Limited Variable Step-Size Algorithm Based on the MSD Variation Cost Function Open Access

    Yufei HAN  Jiaye XIE  Yibo LI  

     
    LETTER-Digital Signal Processing

      Pubricized:
    2023/09/11
      Vol:
    E107-A No:6
      Page(s):
    919-922

    The steady-state and convergence performances are important indicators to evaluate adaptive algorithms. The step-size affects these two important indicators directly. Many relevant scholars have also proposed some variable step-size adaptive algorithms for improving performance. However, there are still some problems in these existing variable step-size adaptive algorithms, such as the insufficient theoretical analysis, the imbalanced performance and the unachievable parameter. These problems influence the actual performance of some algorithms greatly. Therefore, we intend to further explore an inherent relationship between the key performance and the step-size in this paper. The variation of mean square deviation (MSD) is adopted as the cost function. Based on some theoretical analyses and derivations, a novel variable step-size algorithm with a dynamic limited function (DLF) was proposed. At the same time, the sufficient theoretical analysis is conducted on the weight deviation and the convergence stability. The proposed algorithm is also tested with some typical algorithms in many different environments. Both the theoretical analysis and the experimental result all have verified that the proposed algorithm equips a superior performance.

  • Multi-Dimensional Fused Gromov Wasserstein Discrepancy for Edge-Attributed Graphs Open Access

    Keisuke KAWANO  Satoshi KOIDE  Hiroaki SHIOKAWA  Toshiyuki AMAGASA  

     
    PAPER

      Pubricized:
    2024/01/12
      Vol:
    E107-D No:5
      Page(s):
    683-693

    Graph dissimilarities provide a powerful and ubiquitous approach for applying machine learning algorithms to edge-attributed graphs. However, conventional optimal transport-based dissimilarities cannot handle edge-attributes. In this paper, we propose an optimal transport-based dissimilarity between graphs with edge-attributes. The proposed method, multi-dimensional fused Gromov-Wasserstein discrepancy (MFGW), naturally incorporates the mismatch of edge-attributes into the optimal transport theory. Unlike conventional optimal transport-based dissimilarities, MFGW can directly handle edge-attributes in addition to structural information of graphs. Furthermore, we propose an iterative algorithm, which can be computed on GPUs, to solve non-convex quadratic programming problems involved in MFGW.  Experimentally, we demonstrate that MFGW outperforms the conventional optimal transport-based dissimilarity in several machine learning applications including supervised classification, subgraph matching, and graph barycenter calculation.

  • Effects of Electromagnet Interference on Speed and Position Estimations of Sensorless SPMSM Open Access

    Yuanhe XUE  Wei YAN  Xuan LIU  Mengxia ZHOU  Yang ZHAO  Hao MA  

     
    PAPER-Electromechanical Devices and Components

      Pubricized:
    2023/11/10
      Vol:
    E107-C No:5
      Page(s):
    124-131

    Model-based sensorless control of permanent magnet synchronous motor (PMSM) is promising for high-speed operation to estimate motor state, which is the speed and the position of the rotor, via electric signals of the stator, beside the inevitable fact that estimation accuracy is degraded by electromagnet interference (EMI) from switching devices of the converter. In this paper, the simulation system based on Luenberger observer and phase-locked loop (PLL) has been established, analyzing impacts of EMI on motor state estimations theoretically, exploring influences of EMI with different cutoff frequency, rated speeds, frequencies and amplitudes. The results show that Luenberger observer and PLL have strong immunity, which enable PMSM can still operate stably even under certain degrees of interference. EMI produces sideband harmonics that enlarge pulsation errors of speed and position estimations. Additionally, estimation errors are positively correlated with cutoff frequency of low-pass filter and the amplitude of EMI, and negatively correlated with rated speed of the motor and the frequency of EMI.  When the frequency is too high, its effects on motor state estimations are negligible. This work contributes to the comprehensive understanding of how EMI affects motor state estimations, which further enhances practical application of sensorless PMSM.

  • Meta-Bound on Lower Bounds of Bayes Risk in Parameter Estimation

    Shota SAITO  

     
    PAPER-Estimation

      Pubricized:
    2023/08/09
      Vol:
    E107-A No:3
      Page(s):
    503-509

    Information-theoretic lower bounds of the Bayes risk have been investigated for a problem of parameter estimation in a Bayesian setting. Previous studies have proven the lower bound of the Bayes risk in a different manner and characterized the lower bound via different quantities such as mutual information, Sibson's α-mutual information, f-divergence, and Csiszár's f-informativity. In this paper, we introduce an inequality called a “meta-bound for lower bounds of the Bayes risk” and show that the previous results can be derived from this inequality.

  • An Adaptive Energy-Efficient Uneven Clustering Routing Protocol for WSNs

    Mingyu LI  Jihang YIN  Yonggang XU  Gang HUA  Nian XU  

     
    PAPER-Network

      Vol:
    E107-B No:2
      Page(s):
    296-308

    Aiming at the problem of “energy hole” caused by random distribution of nodes in large-scale wireless sensor networks (WSNs), this paper proposes an adaptive energy-efficient balanced uneven clustering routing protocol (AEBUC) for WSNs. The competition radius is adaptively adjusted based on the node density and the distance from candidate cluster head (CH) to base station (BS) to achieve scale-controlled adaptive optimal clustering; in candidate CHs, the energy relative density and candidate CH relative density are comprehensively considered to achieve dynamic CH selection. In the inter-cluster communication, based on the principle of energy balance, the relay communication cost function is established and combined with the minimum spanning tree method to realize the optimized inter-cluster multi-hop routing, forming an efficient communication routing tree. The experimental results show that the protocol effectively saves network energy, significantly extends network lifetime, and better solves the “energy hole” problem.

  • Adaptive K-Repetition Transmission with Site Diversity Reception for Energy-Efficient Grant-Free URLLC in 5G NR

    Arif DATAESATU  Kosuke SANADA  Hiroyuki HATANO  Kazuo MORI  Pisit BOONSRIMUANG  

     
    PAPER

      Pubricized:
    2023/10/11
      Vol:
    E107-B No:1
      Page(s):
    74-84

    The fifth-generation (5G) new radio (NR) standard employs ultra-reliable and low-latency communication (URLLC) to provide real-time wireless interactive capability for the internet of things (IoT) applications. To satisfy the stringent latency and reliability demands of URLLC services, grant-free (GF) transmissions with the K-repetition transmission (K-Rep) have been introduced. However, fading fluctuations can negatively impact signal quality at the base station (BS), leading to an increase in the number of repetitions and raising concerns about interference and energy consumption for IoT user equipment (UE). To overcome these challenges, this paper proposes novel adaptive K-Rep control schemes that employ site diversity reception to enhance signal quality and reduce energy consumption. The performance evaluation demonstrates that the proposed adaptive K-Rep control schemes significantly improve communication reliability and reduce transmission energy consumption compared with the conventional K-Rep scheme, and then satisfy the URLLC requirements while reducing energy consumption.

  • Robust Recursive Identification of ARX Models Using Beta Divergence

    Shuichi FUKUNAGA  

     
    LETTER-Systems and Control

      Pubricized:
    2023/06/02
      Vol:
    E106-A No:12
      Page(s):
    1580-1584

    The robust recursive identification method of ARX models is proposed using the beta divergence. The proposed parameter update law suppresses the effect of outliers using a weight function that is automatically determined by minimizing the beta divergence. A numerical example illustrates the efficacy of the proposed method.

  • Stackelberg Game for Wireless-Powered Relays Assisted Batteryless IoT Networks

    Yanming CHEN  Bin LYU  Zhen YANG  Fei LI  

     
    PAPER-Wireless Communication Technologies

      Pubricized:
    2023/08/10
      Vol:
    E106-B No:12
      Page(s):
    1479-1490

    In this paper, we investigate a wireless-powered relays assisted batteryless IoT network based on the non-linear energy harvesting model, where there exists an energy service provider constituted by the hybrid access point (HAP) and an IoT service provider constituted by multiple clusters. The HAP provides energy signals to the batteryless devices for information backscattering and the wireless-powered relays for energy harvesting. The relays are deployed to assist the batteryless devices with the information transmission to the HAP by using the harvested energy. To model the energy interactions between the energy service provider and IoT service provider, we propose a Stackelberg game based framework. We aim to maximize the respective utility values of the two providers. Since the utility maximization problem of the IoT service provider is non-convex, we employ the fractional programming theory and propose a block coordinate descent (BCD) based algorithm with successive convex approximation (SCA) and semi-definite relaxation (SDR) techniques to solve it. Numerical simulation results confirm that compared to the benchmark schemes, our proposed scheme can achieve larger utility values for both the energy service provider and IoT service provider.

  • Evaluating Energy Consumption of Internet Services Open Access

    Leif Katsuo OXENLØWE  Quentin SAUDAN  Jasper RIEBESEHL  Mujtaba ZAHIDY  Smaranika SWAIN  

     
    INVITED PAPER

      Pubricized:
    2023/06/15
      Vol:
    E106-B No:11
      Page(s):
    1036-1043

    This paper summarizes recent reports on the internet's energy consumption and the internet's benefits on climate actions. It discusses energy-efficiency and the need for a common standard for evaluating the climate impact of future communication technologies and suggests a model that can be adapted to different internet applications such as streaming, online reading and downloading. The two main approaches today are based on how much data is transmitted or how much time the data is under way. The paper concludes that there is a need for a standardized method to estimate energy consumption and CO2 emission related to internet services. This standard should include a method for energy-optimizing future networks, where every Wh will be scrutinized.

  • Transfer Discriminant Softmax Regression with Weighted MMD

    Xinghai LI  Shaofei ZANG  Jianwei MA  Xiaoyu MA  

     
    PAPER-Language, Thought, Knowledge and Intelligence

      Pubricized:
    2023/04/20
      Vol:
    E106-A No:10
      Page(s):
    1343-1353

    As an efficient classical machine learning classifier, the Softmax regression uses cross-entropy as the loss function. Therefore, it has high accuracy in classification. However, when there is inconsistency between the distribution of training samples and test samples, the performance of traditional Softmax regression models will degrade. A transfer discriminant Softmax regression model called Transfer Discriminant Softmax Regression with Weighted MMD (TDS-WMMD) is proposed in this paper. With this method, the Weighted Maximum Mean Divergence (WMMD) is introduced into the objective function to reduce the marginal distribution and conditional distribution between domains both locally and globally, realizing the cross domain transfer of knowledge. In addition, to further improve the classification performance of the model, Linear Discriminant Analysis (LDA) is added to the label iteration refinement process to improve the class separability of the designed method by keeping the same kind of samples together and the different kinds of samples repeling each other. Finally, after conducting classification experiments on several commonly used public transfer learning datasets, the results verify that the designed method can enhance the knowledge transfer ability of the Softmax regression model, and deliver higher classification performance compared with other current transfer learning classifiers.

  • Energy Efficiency Based Multi Service Heterogeneous Access Network Selection Algorithm

    Meng-Yuan HE  Ling-Yun JIANG  

     
    PAPER-Network System

      Pubricized:
    2023/04/24
      Vol:
    E106-B No:10
      Page(s):
    881-890

    In the current heterogeneous wireless communication system, the sharp rise in energy consumption and the emergence of new service types pose great challenges to nowadays radio access network selection algorithms which do not take care of these new trends. So the proposed energy efficiency based multi-service heterogeneous access network selection algorithm-ESRS (Energy Saving Radio access network Selection) is intended to reduce the energy consumption caused by the traffic in the mobile network system composed of Base Stations (BSs) and Access Points (APs). This algorithm models the access network selection problem as a Multiple-Attribute Decision-Making (MADM) problem. To solve this problem, lots of methods are combined, including analytic Hierarchy Process (AHP), weighted grey relational analysis (GRA), entropy theory, simple additive weight (SAW), and utility function theory. There are two main steps in this algorithm. At first, the proposed algorithm gets the result of the user QoS of each network by dealing with the related QoS parameters, in which entropy theory and AHP are used to determine the QoS comprehensive weight, and the SAW is used to get each network's QoS. In addition to user QoS, parameters including user throughput, energy consumption utility and cost utility are also calculated in this step. In the second step, the fuzzy theory is used to define the weight of decision attributes, and weighted grey relational analysis (GRA) is used to calculate the network score, which determines the final choice. Because the fuzzy weight has a preference for the low energy consumption, the energy consumption of the traffic will be saved by choosing the network with the least energy consumption as much as possible. The simulation parts compared the performance of ESRS, ABE and MSNS algorithms. The numerical results show that ESRS algorithm can select the appropriate network based on the service demands and network parameters. Besides, it can effectively reduce the system energy consumption and overall cost while still maintaining a high overall QoS value and a high system throughput, when compared with the other two algorithms.

  • Nonvolatile Storage Cells Using FiCC for IoT Processors with Intermittent Operations

    Yuki ABE  Kazutoshi KOBAYASHI  Jun SHIOMI  Hiroyuki OCHI  

     
    PAPER

      Pubricized:
    2023/04/13
      Vol:
    E106-C No:10
      Page(s):
    546-555

    Energy harvesting has been widely investigated as a potential solution to supply power for Internet of Things (IoT) devices. Computing devices must operate intermittently rather than continuously, because harvested energy is unstable and some of IoT applications can be periodic. Therefore, processors for IoT devices with intermittent operation must feature a hibernation mode with zero-standby-power in addition to energy-efficient normal mode. In this paper, we describe the layout design and measurement results of a nonvolatile standard cell memory (NV-SCM) and nonvolatile flip-flops (NV-FF) with a nonvolatile memory using Fishbone-in-Cage Capacitor (FiCC) suitable for IoT processors with intermittent operations. They can be fabricated in any conventional CMOS process without any additional mask. NV-SCM and NV-FF are fabricated in a 180nm CMOS process technology. The area overhead by nonvolatility of a bit cell are 74% in NV-SCM and 29% in NV-FF, respectively. We confirmed full functionality of the NV-SCM and NV-FF. The nonvolatile system using proposed NV-SCM and NV-FF can reduce the energy consumption by 24.3% compared to the volatile system when hibernation/normal operation time ratio is 500 as shown in the simulation.

  • Hybrid, Asymmetric and Reconfigurable Input Unit Designs for Energy-Efficient On-Chip Networks

    Xiaoman LIU  Yujie GAO  Yuan HE  Xiaohan YUE  Haiyan JIANG  Xibo WANG  

     
    PAPER

      Pubricized:
    2023/04/10
      Vol:
    E106-C No:10
      Page(s):
    570-579

    The complexity and scale of Networks-on-Chip (NoCs) are growing as more processing elements and memory devices are implemented on chips. However, under strict power budgets, it is also critical to lower the power consumption of NoCs for the sake of energy efficiency. In this paper, we therefore present three novel input unit designs for on-chip routers attempting to shrink their power consumption while still conserving the network performance. The key idea behind our designs is to organize buffers in the input units with characteristics of the network traffic in mind; as in our observations, only a small portion of the network traffic are long packets (composed of multiple flits), which means, it is fair to implement hybrid, asymmetric and reconfigurable buffers so that they are mainly targeting at short packets (only having a single flit), hence the smaller power consumption and area overhead. Evaluations show that our hybrid, asymmetric and reconfigurable input unit designs can achieve an average reduction of energy consumption per flit by 45%, 52.3% and 56.2% under 93.6% (for hybrid designs) and 66.3% (for asymmetric and reconfigurable designs) of the original router area, respectively. Meanwhile, we only observe minor degradation in network latency (ranging from 18.4% to 1.5%, on average) with our proposals.

  • Digital Rights Management System of Media Convergence Center Based on Ethereum and IPFS

    Runde YU  Zhuowen LI  Zhe CHEN  Gangyi DING  

     
    PAPER-Multimedia Pattern Processing

      Pubricized:
    2023/05/02
      Vol:
    E106-D No:8
      Page(s):
    1275-1282

    In order to solve the problems of copyrights infringement, high cost and complex process of rights protection in current media convergence center, a digital rights management system based on blockchain technology and IPFS (Inter Planetary File System) technology is proposed. Considering that large files such as video and audio cannot be stored on the blockchain directly, IPFS technology is adopted as the data expansion scheme for the data storage layer of the Ethereum platform, IPFS protocol is further used for distributed data storage and transmission of media content. In addition, smart contract is also used to uniquely identify digital rights through NFT (Non-fungible Tokens), which provides the characteristics of digital rights transferability and traceability, and realizes an open, transparent, tamper-proof and traceable digital rights management system for media convergence center. Several experimental results show that it has higher transaction success rate, lower storage consumption and transaction confirmation delay than existing scheme.

1-20hit(867hit)