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A Dual-Cluster-Head Based Medium Access Control for Large-Scale UAV Ad-Hoc Networks

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China Communications 2024年第5期21卷 123-136页

作者： Zhao Xinru Wei Zhiqing Zou Yingying Ma Hao Cui Yanpeng feng zhiyong Key Laboratory of Universal Wireless Communications Ministry of EducationSchool of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing100876China

Unmanned Aerial Vehicle(UAV)ad hoc network has achieved significant growth for its flexibility,extensibility,and high deployability in recent *** application of clustering scheme for UAV ad hoc network is imperative to enhance the performance of throughput and energy *** conventional clustering scheme,a single cluster head(CH)is always assigned in each ***,this method has some weaknesses such as overload and premature death of CH when the number of UAVs *** order to solve this problem,we propose a dual-cluster-head based medium access control(DCHMAC)scheme for large-scale UAV *** DCHMAC,two CHs are elected to manage resource allocation and data forwarding ***,two CHs work on different *** of CH is used for intra-cluster communication and the other one is for inter-cluster communication.A Markov chain model is developed to analyse the throughput of the *** result shows that compared with FM-MAC(flying ad hoc networks multi-channel MAC,FM-MAC),DCHMAC improves the throughput by approximately 20%~50%and prolongs the network lifetime by approximately 40%.

关键词： dual cluster head medium access control UAV swarm

Sensing-Assisted Accurate and Fast Beam Management for Cellular-Connected mmWave UAV Network

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China Communications 2024年第6期21卷 271-289页

作者： Cui Yanpeng Zhang Qixun feng zhiyong Qin Wen Zhou Ying Wei Zhiqing Zhang Ping School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China School of Computer Science Northwestern Polytechnical UniversityXi’an 710072China

Beam management,including initial access(IA)and beam tracking,is essential to the millimeter-wave Unmanned Aerial Vehicle(UAV)***,the conventional communicationonly and feedback-based schemes suffer a high delay and low accuracy of beam alignment,since they only enable the receiver to passively“hear”the information of the transmitter from the radio *** paper presents a novel sensing-assisted beam management approach,the first solution that fully utilizes the information from the visual domain to improve communication *** employ both integrated sensing and communication and computer vision techniques and design an extended Kalman filtering method for beam tracking and ***,we also propose a novel dual identity association solution to distinguish multiple UAVs in dynamic ***-world experiments and numerical results show that the proposed solution outperforms the conventional methods in IA delay,association accuracy,tracking error,and communication performance.

关键词： beam management integrated sensing and communication UAV communication

Cluster-based RSU deployment strategy for vehicular ad hoc networks with integration of communication,sensing and computing

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Journal of Information and Intelligence 2024年第4期2卷 325-338页

作者： Xinrui Gu Shengfeng Wang Zhiqing Wei zhiyong feng Key Laboratory of Universal Wireless Communications Ministry of EducationSchool of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing 100876China

The integration of communications,sensing and computing(I-CSC)has significant applications in vehicular ad hoc networks(VANETs).A roadside unit(RSU)plays an important role in I-CSC by performing functions such as information transmission and edge computing in vehicular *** to the constraints of limited resources,RSU cannot achieve full coverage and deploying RSUs at key cluster heads of hierarchical structures of road networks is an effective management ***,direct extracting the hierarchical structures for the resource allocation in VANETs is an open *** this paper,we proposed a network-based renormalization method based on information flow and geographical location to hierarchically deploy the RSU on the road *** renormalization method is compared with two deployment schemes:genetic algorithm(GA)and memetic framework-based optimal RSU deployment(MFRD),to verify the improvement of communication *** results show that the renormalization method is superior to other schemes in terms of RSU coverage and information reception rate.

关键词： Roadside unit(RSU)deployment strategy Vehicular ad hoc networks(VANETs) Hierarchical structures Renormalization group Complex network

动静互补平衡论功能锻炼结合阶梯性康复训练利于全髋关节置换者术后髋关节功能恢复

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四川大学学报（医学版） 2024年第4期55卷 1014-1019页

作者：许德龙韩红左伟冯志勇武汉市第四医院康复医学科武汉430000 武汉市第四医院创伤骨科武汉430000

目的分析动静互补平衡论的功能锻炼结合阶梯性康复训练在全髋关节置换(total hip replacement, THR患者术后髋关节功能恢复的应用价值。方法回顾性收集2022年6月–2023年6月收治的118例THR患者临床资料,其中57例围术期给予阶梯性康复... 详细信息

目的分析动静互补平衡论的功能锻炼结合阶梯性康复训练在全髋关节置换(total hip replacement, THR患者术后髋关节功能恢复的应用价值。方法回顾性收集2022年6月–2023年6月收治的118例THR患者临床资料,其中57例围术期给予阶梯性康复训练(对照组),61例围术期行动静互补平衡论功能锻炼结合阶梯性康复训练(联合组)。记录两组术后恢复情况及术后并发症发生情况,在围术期评估两组患者疼痛[视觉模拟评分法(visual analogue scale, VAS)]及自我效能感[康复自我效能感量表(Self-Efficacy for Rehabilitation Outcome Scale, SER)],比较两组术后2周、4周、8周髋关节功能。结果主要结局指标:联合组术后住院时间为(7.63±1.36) d,低于对照组的(8.22±1.48) d,差异有统计学意义(t=2.257,P=0.026)。次要结局指标:两组术后并发症发生率比较(4.92%vs. 14.04%),差异无统计学意义(P>0.05)。两组围术期VAS评分经重复测量方差检验显示具有交互效应(P<0.05),两组术后VAS评分均较术前降低(P<0.05),且随术后时间的延长逐渐降低(P<0.05),联合组术后7 d及14 d VAS评分低于对照组(P<0.05)。术后14 d,两组应对及任务维度SER评分及其总分均较术后3 d升高(P<0.05),联合组高于对照组(P<0.05)。两组术后畸形、疼痛、功能、关节活动度维度Harris髋关节功能评分及其总分经重复测量方差检验显示具有交互效应(P<0.05),两组Harris髋关节功能各维度评分及其总分均随术后时间的延长逐渐升高(P<0.05),联合组术后4周及8周评分均高于对照组(P<0.05)。结论动静互补平衡论的功能锻炼结合阶梯性康复训练在提高THR患者自我效能感、缓解术后疼痛、减少住院时间和改善患者髋关节功能方面,比单纯进行阶梯性康复训练更具优势。

关键词：全髋关节置换术康复动静互补平衡论髋关节功能自我效能感

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动态杂散电流干扰下管地电位的波动特征

腐蚀与防护 2024年第2期45卷 90-96页

作者：马帅杰冯志永杜艳霞陈乐北京科技大学新材料技术研究院北京100083 郑州机械研究所有限公司新型钎焊材料与技术国家重点实验室郑州450001 北京市燃气集团有限责任公司北京100035

在地铁、高铁和高压直流(HVDC)输电系统接地极双极运行引起的动态杂散电流干扰下,现场监测得到196组管地电位数据。在时域上分析了不同干扰下管地电位的动态波动特征,然后利用信号学上连续小波变换(CWT)的方法在频域上研究了不同干扰下... 详细信息

在地铁、高铁和高压直流(HVDC)输电系统接地极双极运行引起的动态杂散电流干扰下,现场监测得到196组管地电位数据。在时域上分析了不同干扰下管地电位的动态波动特征,然后利用信号学上连续小波变换(CWT)的方法在频域上研究了不同干扰下管地电位的动态波动特性,统计了不同干扰下管地电位的周期分布范围,并对比了其周期分布的差异。结果表明:三种干扰源都对管道造成动态直流干扰,其中地铁和高铁干扰呈现白天干扰严重、夜间平稳的周期性变化,而HVDC干扰则与高压直流输电系统接地极入地电流的大小与方向有关,没有明显的昼夜差别;高铁交流干扰同时伴随着显著的直流干扰;地铁直流干扰的周期占比随周期增大呈现先增大后减小的趋势,因高铁线路不同,管道干扰的周期分布也有所不同,但主要分布在大于500s的范围,HVDC干扰引起的管地直流电位波动周期分布较为均匀。

关键词：动态杂散电流管地电位现场数据连续小波变换(CWT) 波动周期

Load-Aware Offloading Strategy in Two-Tier Heterogeneous Network

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China Communications 2016年第8期13卷 148-158页

作者： Jianyuan feng zhiyong feng Zhiqing Wei Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications

Although small cell offloading technology can alleviate the congestion in macrocell, aggressively offloading data traffic from macrocell to small cell can also degrade the performance of small cell due to the heavy load. Because of collision and backoff, the degradation is significant especially in network with contention-based channel access, and finally decreases throughput of the whole network. To find an optimal fraction of traffic to be offloaded in heterogeneous network, we combine Markov chain with the Poisson point process model to analyze contention-based throughput in irregularly deployment networks. Then we derive the close-form solution of the throughput and find that it is a function of the transmit power and density of base *** on this, we propose the load-aware offloading strategies via power control and base station density adjustment. The numerical results verify our analysis and show a great performance gain compared with non-load-aware offloading.

关键词： heterogeneous networks offloading strategies load-aware Poisson point process Markov chain throughput maximization CSMA

A Survey of Security Issues in Cognitive Radio Networks

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China Communications 2015年第3期12卷 132-150页

作者： LI Jianwu feng Zebing feng zhiyong ZHANG Ping Network Information Processing Center State Key Laboratory of Networking and Switching TechnologyBeijing University of Posts and Telecommunications Key Laboratory of Universal Wireless Communications Ministry of Education Beijing University of Posts and Telecommunications

In the last decade,cognitive radio(CR) has emerged as a major next generation wireless networking technology,which is the most promising candidate solution to solve the spectrum scarcity and improve the spectrum ***,there exist enormous challenges for the open and random access environment of CRNs,where the unlicensed secondary users(SUs) can use the channels that are not currently used by the licensed primary users(PUs) via spectrum-sensing *** of this access method,some malicious users may access the cognitive network arbitrarily and launch some special attacks,such as primary user emulation attack,falsifying data or denial of service attack,which will cause serious damage to the cognitive radio *** addition to the specifi c security threats of cognitive network,CRNs also face up to the conventional security threats,such as eavesdropping,tampering,imitation,forgery,and noncooperation etc..Hence,Cognitive radio networks have much more risks than traditional wireless networks with its special network *** this paper,we considered the security threats from passive and active ***,the PHY layer security is presented in the view of passive attacks,and it is a compelling idea of using the physical properties of the radio channel to help provide secure wireless ***,malicious user detection is introduced in the view of active attacks by means of the signal detection techniques to decrease the interference and the probabilities of false alarm and missed ***,we discuss the general countermeasures of security threats in three *** particular,we discuss the far reaching effect of defensive strategy against attacks in CRNs.

关键词： CRNs security physical layer security security capacity active attacks passive attacks

Spectrum Allocation and Performance Analysis for Backhauling of UAV Assisted Cellular Network

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China Communications 2019年第8期16卷 72-81页

作者： Lei Ji Jingran Chen zhiyong feng Key Laboratory of Universal Wireless Communications Ministry of Education Wireless Technology Innovation Institute (WTI)Beijing University of Posts and Telecommunications

To reinforce the coverage and QoS(quality of service) of on-ground cellular communication system, unmanned aerial vehicles which are carrying small cells are deployed in some emergency and disaster areas. Although ASCs(aerial small cells) can provide a higher probability of LoS(line-of-sight) transmission, the wireless backhaul link will bring extra interference to the whole system if not well designed. Therefore, in this paper, we study the backhaul scheme for UAV-assist cellular network. We first analyze the interference environments of UAV-assist cellular network considering the IBOG(In-Band to On-Ground), OBOG(Out-of-Band to On-Ground) and IBTU(In-Band to Tethered-UAV) backhauling mode, and give the descriptions of the performance metrics for each mode. Then, the considered problem is formulated as an optimization of achievable rate. We derive the optimal solutions for the involved three backhauling modes for ASCs respectively, and closed-form optimal value for each mode is acquired with proof. We also give a pseudo-code form of our proposed optimal access/backhaul spectrum allocation algorithm. The simulation results indicate that the proposed scheme can deliver a significant gain, while IBTU performs best among proposed backhauling modes.

关键词： UAV backhauling spectrum allocation

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我国黄毛鼠研究进展

植物保护 2024年第3期50卷 17-23,45页

作者：姜洪雪姚丹丹林思亮秦姣冯志勇广东省农业科学院植物保护研究所农业农村部华南果蔬绿色防控重点实验室广东省植物保护新技术重点实验室广州510640

黄毛鼠Rattus losea是分布在中国长江以南地区以及东南亚地区的重要农田害鼠。该鼠栖息地广,食性杂,盗食各种农作物,还是某些疾病的宿主和传播者。本文从形态特征、种群遗传学、生物学特性、种群生态学、抗药性、防治技术等方面详细介... 详细信息

黄毛鼠Rattus losea是分布在中国长江以南地区以及东南亚地区的重要农田害鼠。该鼠栖息地广,食性杂,盗食各种农作物,还是某些疾病的宿主和传播者。本文从形态特征、种群遗传学、生物学特性、种群生态学、抗药性、防治技术等方面详细介绍了黄毛鼠的研究进展。并根据目前的研究现状和存在问题,提出建立基于精准预测预报,研发生态优先、环境友好的防控新技术、新产品为核心的综合防控技术体系,以期为黄毛鼠的可持续治理提供参考。

关键词：黄毛鼠生物学特性种群动态抗药性防治技术

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