针对含光伏(photovoltaic,PV)、电动汽车(electric vehicle,EV)及家庭电器负荷的智能社区,以车入户(vehicle to home,V2H)的形式将EV纳入家庭需求响应框架,利用EV的双向输能特性并考虑EV充/放电带来的电池容量退化成本,协同PV、电网的...针对含光伏(photovoltaic,PV)、电动汽车(electric vehicle,EV)及家庭电器负荷的智能社区,以车入户(vehicle to home,V2H)的形式将EV纳入家庭需求响应框架,利用EV的双向输能特性并考虑EV充/放电带来的电池容量退化成本,协同PV、电网的实时电价和用户需求的可容忍时延,基于Lyapunov优化理论提出随机环境下V2H用户的EV充/放电调度策略和每户家庭的负荷响应策略,最小化家庭用户的长期平均购电成本。并提出一种智能社区在线能量交易方案,旨在最小化智能社区总的购电成本、最大限度提高社区能源利用率。理论分析和仿真结果表明,所提算法无需实时电价、PV出力、用户负荷需求的先验概率信息,仅基于当前系统状态就可使优化目标趋于最优值,实现家庭用户的能量调度和家庭用户之间的能量共享,减少家庭购电成本,提高用户之间能量交易的灵活性。展开更多
为了充分利用停车场的场地资源和电动汽车(electric vehicles,EV)作为电力系统灵活性资源的功率调节能力,该文针对公共停车场的充电桩配置问题,提出多种容量规格V2G(vehicle to grid)型单充多枪充电桩(V2G single output multiple cable...为了充分利用停车场的场地资源和电动汽车(electric vehicles,EV)作为电力系统灵活性资源的功率调节能力,该文针对公共停车场的充电桩配置问题,提出多种容量规格V2G(vehicle to grid)型单充多枪充电桩(V2G single output multiple cables charging piles,V2G-SOMC)的协同优化配置方法。在对V2G-SOMC型充电桩运行原理和EV充电行为特性分析的基础上,通过精细化时序模拟用户在选择合适容量规格充电桩情况下的充电站运行过程,构建了以投资运行净收益最大为目标的充电桩优化配置模型;针对模型中存在的非线性条件场景约束问题,通过模型转换和大M法进行线性化处理,将其转化为大规模混合整数线性规划模型,并使用Gurobi求解器进行求解;最后,对多种配置方案进行对比分析,验证了所提方法的有效性与先进性。研究结果能够促进公共停车场充电桩配置的合理性,有利于充分利用社会资源以及提高EV用户的满意度。展开更多
为提高全球定位系统(GPS)数据精度,同时解决常规粒子滤波算法在数据处理中的粒子退化、对噪声敏感与样本空间覆盖不均匀等问题,提出一种基于粒子群粒子滤波(PSO-PF)的车联网车对行人(Vehicle to Pedestrian,V2P)定位精度提升方法。首先...为提高全球定位系统(GPS)数据精度,同时解决常规粒子滤波算法在数据处理中的粒子退化、对噪声敏感与样本空间覆盖不均匀等问题,提出一种基于粒子群粒子滤波(PSO-PF)的车联网车对行人(Vehicle to Pedestrian,V2P)定位精度提升方法。首先建立GPS数据的状态模型与测量模型,并对粒子滤波算法存在的问题进行分析;然后引入粒子群优化算法,提出一种防止粒子退化、去除噪声影响、改善粒子空间分布的方法;为验证算法性能,搭建MATLAB/SUMO联合仿真平台,以无迹卡尔曼滤波(UKF)为基准进行对比试验,通过行人测量试验与城市峡谷试验测试两种算法的性能,结果表明,与UKF相比,PSO-PF的定位精度提升72.7%,在非线性条件下其归一化均方误差较小、定位精度更高。展开更多
Vehicular communication systems rely on secure vehicle-to-vehicle(V2V)communications for safety-critical information exchange.However,the presence of eavesdropping vehicles poses a significant challenge.This paper inv...Vehicular communication systems rely on secure vehicle-to-vehicle(V2V)communications for safety-critical information exchange.However,the presence of eavesdropping vehicles poses a significant challenge.This paper investigates the security of V2V communications in reconfigurable intelligent surface(RIS)-assisted vehicular communication systems with spectrum sharing.It proposes a three-stage alternating optimization(TSAO)algorithm to address the complex problem of multiple eavesdropped V2V links that reuse the spectrum already occupied by vehicle-toinfrastructure(V2I)links.To solve the mixed-integer and non-convex optimization problem due to coupled variables and complex constraints,the algorithm decomposes the original problem into three easily solvable sub-problems:RIS reflection coefficient optimization,vehicle transmission power optimization,and spectrum sharing optimization.First,the RIS reflection coefficients are optimized by using the penalty convex-concave procedure(CCP)method.Second,the optimal power points are determined in the power optimization sub-problem.Finally,the spectrum sharing optimization sub-problem is constructed as a weighted bipartite graph matching problem and solved by using the optimal matching algorithm.The TSAO algorithm not only maximizes the sum V2V secrecy rate but also ensures the quality-of-service(QoS)requirements of the V2I links.Simulation results validate the superiority of the proposed algorithm and highlight the improvement in the sum V2V secrecy rate achieved by utilizing RIS technology in vehicular communication systems with spectrum sharing.展开更多
This study proposes a lightweight rice disease detection model optimized for edge computing environments.The goal is to enhance the You Only Look Once(YOLO)v5 architecture to achieve a balance between real-time diagno...This study proposes a lightweight rice disease detection model optimized for edge computing environments.The goal is to enhance the You Only Look Once(YOLO)v5 architecture to achieve a balance between real-time diagnostic performance and computational efficiency.To this end,a total of 3234 high-resolution images(2400×1080)were collected from three major rice diseases Rice Blast,Bacterial Blight,and Brown Spot—frequently found in actual rice cultivation fields.These images served as the training dataset.The proposed YOLOv5-V2 model removes the Focus layer from the original YOLOv5s and integrates ShuffleNet V2 into the backbone,thereby resulting in both model compression and improved inference speed.Additionally,YOLOv5-P,based on PP-PicoDet,was configured as a comparative model to quantitatively evaluate performance.Experimental results demonstrated that YOLOv5-V2 achieved excellent detection performance,with an mAP 0.5 of 89.6%,mAP 0.5–0.95 of 66.7%,precision of 91.3%,and recall of 85.6%,while maintaining a lightweight model size of 6.45 MB.In contrast,YOLOv5-P exhibited a smaller model size of 4.03 MB,but showed lower performance with an mAP 0.5 of 70.3%,mAP 0.5–0.95 of 35.2%,precision of 62.3%,and recall of 74.1%.This study lays a technical foundation for the implementation of smart agriculture and real-time disease diagnosis systems by proposing a model that satisfies both accuracy and lightweight requirements.展开更多
V2X communication enables vehicles to share real-time traffic and road-condition data,but binding messages to persistent identifiers enables location tracking.Furthermore,since forged reports from malicious vehicles c...V2X communication enables vehicles to share real-time traffic and road-condition data,but binding messages to persistent identifiers enables location tracking.Furthermore,since forged reports from malicious vehicles can distort trust decisions and threaten road safety,privacy-preserving trust management is essential.Lu et al.previously presented BARS,an anonymous reputation mechanism founded on blockchain technology to establish a privacy-preserving trust architecture for V2X communication.In this system,reputation certificates without a vehicle identifier ensure anonymity,while two authorities jointly manage certificate issuance and reputation updates.However,the centralized certificate updates introduce scalability limitations,and the authorities can trace vehicle behavioral information,which threatens privacy guarantees.Several subsequent systems derived from BARS still rely on centralized certificate management and are subject to authority-side privacy leakage.As a result,a key challenge in this line of research remains unresolved:how to decentralize the certificate-update process while preserving privacy against the authorities in privacy-preservingV2X trustmanagement.In this paper,we propose a distributed anonymous reputation system for V2X communication,based on an anonymous reputation system for crowdsensing.In our proposed system for V2X communication,the server is distributed to a certificate authority(CA)and roadside units(RSUs).Each vehicle shows the reputation level to the nearest RSU at the beginning of each time interval,and registers a short-time public key.In the interval,the messages from the vehicle are authenticated under the public key and are scored.At the end of the interval,the nearest RSU updates the certificate anonymously.Our solution decentralizes the certificate-update process by assigning each update to the nearest RSU.A zero-knowledge-proof-based show protocol removes the need for any central authority to handle vehicle certificates and thus prevents the authorities from tracing vehicle activities.Compared with BARS,where centralized authorities must update the reputation certificates of many vehicles and may incur communication and processing delays,our system performs each update locally at the nearest RSUonce per interval.The required interaction consists only of a fewkilobytes of communication and a zero-knowledge proof that is almost fully precomputed on the vehicle side,while the RSU-side processing is estimated to take about 40 ms based on timingmeasurements of the underlying cryptographic operations.This distributed updatemodel avoids the centralized bottleneck of BARS and simultaneously removes the privacy risk arising from authority collusion.展开更多
文摘针对含光伏(photovoltaic,PV)、电动汽车(electric vehicle,EV)及家庭电器负荷的智能社区,以车入户(vehicle to home,V2H)的形式将EV纳入家庭需求响应框架,利用EV的双向输能特性并考虑EV充/放电带来的电池容量退化成本,协同PV、电网的实时电价和用户需求的可容忍时延,基于Lyapunov优化理论提出随机环境下V2H用户的EV充/放电调度策略和每户家庭的负荷响应策略,最小化家庭用户的长期平均购电成本。并提出一种智能社区在线能量交易方案,旨在最小化智能社区总的购电成本、最大限度提高社区能源利用率。理论分析和仿真结果表明,所提算法无需实时电价、PV出力、用户负荷需求的先验概率信息,仅基于当前系统状态就可使优化目标趋于最优值,实现家庭用户的能量调度和家庭用户之间的能量共享,减少家庭购电成本,提高用户之间能量交易的灵活性。
文摘为了充分利用停车场的场地资源和电动汽车(electric vehicles,EV)作为电力系统灵活性资源的功率调节能力,该文针对公共停车场的充电桩配置问题,提出多种容量规格V2G(vehicle to grid)型单充多枪充电桩(V2G single output multiple cables charging piles,V2G-SOMC)的协同优化配置方法。在对V2G-SOMC型充电桩运行原理和EV充电行为特性分析的基础上,通过精细化时序模拟用户在选择合适容量规格充电桩情况下的充电站运行过程,构建了以投资运行净收益最大为目标的充电桩优化配置模型;针对模型中存在的非线性条件场景约束问题,通过模型转换和大M法进行线性化处理,将其转化为大规模混合整数线性规划模型,并使用Gurobi求解器进行求解;最后,对多种配置方案进行对比分析,验证了所提方法的有效性与先进性。研究结果能够促进公共停车场充电桩配置的合理性,有利于充分利用社会资源以及提高EV用户的满意度。
文摘为提高全球定位系统(GPS)数据精度,同时解决常规粒子滤波算法在数据处理中的粒子退化、对噪声敏感与样本空间覆盖不均匀等问题,提出一种基于粒子群粒子滤波(PSO-PF)的车联网车对行人(Vehicle to Pedestrian,V2P)定位精度提升方法。首先建立GPS数据的状态模型与测量模型,并对粒子滤波算法存在的问题进行分析;然后引入粒子群优化算法,提出一种防止粒子退化、去除噪声影响、改善粒子空间分布的方法;为验证算法性能,搭建MATLAB/SUMO联合仿真平台,以无迹卡尔曼滤波(UKF)为基准进行对比试验,通过行人测量试验与城市峡谷试验测试两种算法的性能,结果表明,与UKF相比,PSO-PF的定位精度提升72.7%,在非线性条件下其归一化均方误差较小、定位精度更高。
基金National Natural Science Foundation of China(Nos.61772130,71171045 and 61901104)Innovation Program of Shanghai Municipal Education Commission,China(No.14YZ130)。
文摘Vehicular communication systems rely on secure vehicle-to-vehicle(V2V)communications for safety-critical information exchange.However,the presence of eavesdropping vehicles poses a significant challenge.This paper investigates the security of V2V communications in reconfigurable intelligent surface(RIS)-assisted vehicular communication systems with spectrum sharing.It proposes a three-stage alternating optimization(TSAO)algorithm to address the complex problem of multiple eavesdropped V2V links that reuse the spectrum already occupied by vehicle-toinfrastructure(V2I)links.To solve the mixed-integer and non-convex optimization problem due to coupled variables and complex constraints,the algorithm decomposes the original problem into three easily solvable sub-problems:RIS reflection coefficient optimization,vehicle transmission power optimization,and spectrum sharing optimization.First,the RIS reflection coefficients are optimized by using the penalty convex-concave procedure(CCP)method.Second,the optimal power points are determined in the power optimization sub-problem.Finally,the spectrum sharing optimization sub-problem is constructed as a weighted bipartite graph matching problem and solved by using the optimal matching algorithm.The TSAO algorithm not only maximizes the sum V2V secrecy rate but also ensures the quality-of-service(QoS)requirements of the V2I links.Simulation results validate the superiority of the proposed algorithm and highlight the improvement in the sum V2V secrecy rate achieved by utilizing RIS technology in vehicular communication systems with spectrum sharing.
文摘This study proposes a lightweight rice disease detection model optimized for edge computing environments.The goal is to enhance the You Only Look Once(YOLO)v5 architecture to achieve a balance between real-time diagnostic performance and computational efficiency.To this end,a total of 3234 high-resolution images(2400×1080)were collected from three major rice diseases Rice Blast,Bacterial Blight,and Brown Spot—frequently found in actual rice cultivation fields.These images served as the training dataset.The proposed YOLOv5-V2 model removes the Focus layer from the original YOLOv5s and integrates ShuffleNet V2 into the backbone,thereby resulting in both model compression and improved inference speed.Additionally,YOLOv5-P,based on PP-PicoDet,was configured as a comparative model to quantitatively evaluate performance.Experimental results demonstrated that YOLOv5-V2 achieved excellent detection performance,with an mAP 0.5 of 89.6%,mAP 0.5–0.95 of 66.7%,precision of 91.3%,and recall of 85.6%,while maintaining a lightweight model size of 6.45 MB.In contrast,YOLOv5-P exhibited a smaller model size of 4.03 MB,but showed lower performance with an mAP 0.5 of 70.3%,mAP 0.5–0.95 of 35.2%,precision of 62.3%,and recall of 74.1%.This study lays a technical foundation for the implementation of smart agriculture and real-time disease diagnosis systems by proposing a model that satisfies both accuracy and lightweight requirements.
文摘V2X communication enables vehicles to share real-time traffic and road-condition data,but binding messages to persistent identifiers enables location tracking.Furthermore,since forged reports from malicious vehicles can distort trust decisions and threaten road safety,privacy-preserving trust management is essential.Lu et al.previously presented BARS,an anonymous reputation mechanism founded on blockchain technology to establish a privacy-preserving trust architecture for V2X communication.In this system,reputation certificates without a vehicle identifier ensure anonymity,while two authorities jointly manage certificate issuance and reputation updates.However,the centralized certificate updates introduce scalability limitations,and the authorities can trace vehicle behavioral information,which threatens privacy guarantees.Several subsequent systems derived from BARS still rely on centralized certificate management and are subject to authority-side privacy leakage.As a result,a key challenge in this line of research remains unresolved:how to decentralize the certificate-update process while preserving privacy against the authorities in privacy-preservingV2X trustmanagement.In this paper,we propose a distributed anonymous reputation system for V2X communication,based on an anonymous reputation system for crowdsensing.In our proposed system for V2X communication,the server is distributed to a certificate authority(CA)and roadside units(RSUs).Each vehicle shows the reputation level to the nearest RSU at the beginning of each time interval,and registers a short-time public key.In the interval,the messages from the vehicle are authenticated under the public key and are scored.At the end of the interval,the nearest RSU updates the certificate anonymously.Our solution decentralizes the certificate-update process by assigning each update to the nearest RSU.A zero-knowledge-proof-based show protocol removes the need for any central authority to handle vehicle certificates and thus prevents the authorities from tracing vehicle activities.Compared with BARS,where centralized authorities must update the reputation certificates of many vehicles and may incur communication and processing delays,our system performs each update locally at the nearest RSUonce per interval.The required interaction consists only of a fewkilobytes of communication and a zero-knowledge proof that is almost fully precomputed on the vehicle side,while the RSU-side processing is estimated to take about 40 ms based on timingmeasurements of the underlying cryptographic operations.This distributed updatemodel avoids the centralized bottleneck of BARS and simultaneously removes the privacy risk arising from authority collusion.
