检索结果-南通市图书馆

Cellular V2X-Based Integrated Sensing and Communication System:Feasibility and Performance Analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2024年第4期33卷 1104-1116页

作者： Yibo LI junhui zhao Jieyu LIAO Fajin HU School of Electronic and Information Engineering Beijing Jiaotong University

Communication and sensing are basically required in intelligent transportation. The combination of two functions can provide a viable way in alleviating concerns about resource limitations. To achieve this, we propose an integrated sensing and communication(ISAC) system based on cellular vehicle-to-everything(C-V2X). We first analyze the feasibility of new radio(NR) waveform for ISAC system. We discuss the possibility of reusing NR waveform for sensing based on current NR-V2X standards. Ambiguity function is calculated to investigate the sensing performance limitation of NR waveform. A C-V2X-based ISAC system is then designed to realize the two tasks in vehicular network simultaneously. We formulate an integrated framework of vehicular communication and automotive sensing using the already-existing NR-V2X network. Based on the proposed ISAC framework, we develop a receiver algorithm for target detection/estimation and communication with minor modifications. We evaluate the performance of the proposed ISAC system with communication throughput, detection probability, and range/velocity estimation *** show that the proposed system achieves high reliability communication with 99.9999% throughput and high accuracy sensing with errors below 1 m and 1 m/s in vehicle scenarios.

关键词： Accuracy Estimation Receivers Reliability theory Integrated sensing and communication Throughput Task analysis

Deployment of Edge Computing Nodes in IoT:Effective Implementation of Simulated Annealing Method Based on User Location

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Communications 2024年第1期21卷 279-296页

作者： junhui zhao Ziyang Zhang Zhenghao Yi Xiaoting Ma Qingmiao Zhang School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China School of Information Engineering East China Jiaotong UniversityNanchang 330013China

Edge computing paradigm for 5G architecture has been considered as one of the most effective ways to realize low latency and highly reliable communication,which brings computing tasks and network resources to the edge of *** deployment of edge computing nodes is a key factor affecting the service performance of edge computing *** this paper,we propose a method for deploying edge computing nodes based on user *** the combination of Simulation of Urban Mobility(SUMO)and Network Simulator-3(NS-3),a simulation platform is built to generate data of hotspot areas in Io T *** effectively using the data generated by the communication between users in Io T scenario,the location area of the user terminal can be *** this basis,the deployment problem is expressed as a mixed integer linear problem,which can be solved by Simulated Annealing(SA)*** analysis of the results shows that,compared with the traditional method,the proposed method has faster convergence speed and better performance.

关键词： deployment problem edge computing internet of things machine learning

裂缝性储层天然缝与水力缝开启条件及扩展规律研究

在线全文

学校读者我要写书评

暂无评论

石油钻探技术 2024年第3期52卷 98-105页

作者：尹帅赵军辉刘平沈志成西安石油大学地球科学与工程学院陕西西安710065 中国石油长庆油田分公司第八采油厂陕西西安710021 中国石油集团测井有限公司长庆分公司陕西西安710201 中国石油长庆油田分公司第七采油厂陕西西安710200

为了揭示裂缝性储层天然裂缝与水力裂缝开启条件及扩展规律,降低水窜风险,采用地应力测试、天然裂缝观察、水力裂缝扩展试验及模拟等方法,系统研究了天然裂缝与水力裂缝开启条件及扩展规律、水平应力差对水力裂缝扩展的影响及天然裂缝... 详细信息

为了揭示裂缝性储层天然裂缝与水力裂缝开启条件及扩展规律,降低水窜风险,采用地应力测试、天然裂缝观察、水力裂缝扩展试验及模拟等方法,系统研究了天然裂缝与水力裂缝开启条件及扩展规律、水平应力差对水力裂缝扩展的影响及天然裂缝与水力裂缝相沟通的净压力。研究结果显示,研究区的垂向应力σ_(v)>最大水平主应力σ_(H)>最小水平主应力σ_(h),垂向应力、最大水平主应力和最小水平主应力的梯度分别为0.025,0.020和0.017 MPa/m;研究区致密砂岩中裂缝滑动的临界压力梯度在0.018~0.020 MPa/m,平均为0.019 MPa/m;当天然裂缝内临界压力梯度超过0.020 MPa/m时,无效缝均转变为有效缝。水平应力差从0增至10 MPa过程中,水力裂缝长度逐渐增加;10 MPa应力差条件下所形成水力裂缝的长度约为0及5 MPa应力差条件下水力裂缝的1.52倍。压裂试验结果显示,当水力裂缝遇到局部发育的砾石颗粒时会发生一定程度偏转,之后会继续沿着原来方向延伸。研究区目的层天然缝张开形成分支裂缝条件下的裂缝沟通净压力梯度为0.003 MPa/m,该裂缝沟通净压力在4.5~9.0 MPa。研究认为,构建裂缝性储层中水力裂缝的非稳态扩展模式时,应综合考虑水平应力差、天然裂缝发育情况、岩性特征及压裂施工条件。

关键词：裂缝性储层水力裂缝天然裂缝裂缝开启裂缝闭合裂缝扩展

维普期刊数据库博看期刊

Intelligent reflecting surface-assisted federated learning in multi-platoon collaborative networks

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2023年第3期9卷 628-637页

作者： Xiaoting Ma junhui zhao Jieyu Liao Ziyang Zhang School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing100044China China Telecom Corporation Limited Research Institute Beijing102209China School of Information Engineering East China Jiaotong UniversityNanchang330013China

Inspired by mobile edge computing(MEC),edge learning has gained a momentum by directly performing model training at network edge without sending massive data to a centralized data ***,the quality of model training will be affected by the limited communication and computing resources of network *** this paper,how to improve the training performance of a federated learning system aided by intelligent reflecting surface(IRS)over vehicle platooning networks is studied,where multiple platoons train a shared federated learning ***-platoon cooperation can alleviate the pressure of data processing caused by the limited computing resources of single ***,IRS can enhance the inter-platoon communication in a cost-effective and energy-efficient ***,the federated learning optimization problem of maximizing the learning accuracy is formulated by jointing platoon scheduling,bandwidth allocation and phase shifts at the IRS to maximize the number of scheduled ***-ically,in the proposed learning architecture each platoon updates the learning model with its own data and uploads it to the global model through IRS-based wireless ***,a method based on sequential optimization algorithm(SOA)and a group-based optimization method are analyzed for single IRS aided and large-scale IRS aided commu-nication,***,a platoon scheduling scheme is designed based on the communication reliability and computing reliability of *** results demonstrate that large-scale IRS assisted communication can effectively improve the reliability of multi-user communication *** scheduling scheme based on learning reliability balances the communication performance and computing performance of platoons.

关键词： Vehicle platooning networks Federated learning Intelligent reflecting surface Platoon scheduling Resource allocation

Mobile Edge Computing Servers Deployment with Improved Genetic Algorithm in Cellular Internet of Things

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国通信:英文版 2023年第9期20卷 215-226页

作者： Huan Zhang junhui zhao Lihua Yang Ziyang Zhang School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China School of Information Engineering East China Jiaotong UniversityNanchang 330013China Lenovo Research Lenovo Group LimitedBeijing 100094China

Mobile edge computing(MEC)provides services to devices and reduces latency in cellular internet of things(IoT)***,the challenging problem is how to deploy MEC servers economically and *** paper investigates the deployment problem of MEC servers of the real-world road network by employing an improved genetic algorithm(GA)*** first use the threshold-based K-means algorithm to form vehicle clusters according to their *** then select base stations(BSs)based on clustering center coordinates as the deployment locations set for potential MEC *** further select BSs using a combined simulated annealing(SA)algorithm and GA to minimize the deployment *** simulation results show that the improved GA deploys MEC servers *** addition,the proposed algorithm outperforms GA and SA algorithms in terms of convergence speed and solution quality.

关键词： deployment of MEC servers IoT im-proved GA cost

在线全文

学校读者我要写书评

暂无评论

高速公路桥梁变宽段曲线横移架梁技术研究

公路工程 2024年第1期49卷 6-15,44页

作者：陈峻熊成赵俊辉胡文韬江西省公路桥梁工程有限公司江西南昌330000 华东交通大学江西南昌330000

在桥梁工程中,对于既处在曲线段又是变宽段的预制梁安装路段往往不可避免,此时一般采用架桥机常规直线横移轨道进行架梁铺设,随之带来的问题是需要令架桥机前、中支腿错位排布,如此一来施工的精度、难度都有所提升,并且存在一定的安全... 详细信息

在桥梁工程中,对于既处在曲线段又是变宽段的预制梁安装路段往往不可避免,此时一般采用架桥机常规直线横移轨道进行架梁铺设,随之带来的问题是需要令架桥机前、中支腿错位排布,如此一来施工的精度、难度都有所提升,并且存在一定的安全隐患。依托于江西宜遂高速公路桥梁某路段,提出了使用曲线横移轨道为架桥机在曲线变宽段进行架梁作业时平稳过渡到支腿错位分布提供条件,以达到缩短工期、保障安全和提高经济效益的目的。

关键词：桥梁工程变宽段曲线横移轨道架梁技术

Understanding the growth mechanisms of metal-based core–shell nanostructures revealed by in situ liquid cell transmission electron microscopy

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2022年第8期31卷 370-383,I0010页

作者： Junyu Zhang Bensheng Xiao junhui zhao Miao Li Haichen Lin Zewen Kang Xianwen Wu Haodong Liu Dong-Liang Peng Qiaobao Zhang Instrumental Analysis Center Laboratory and Equipment Management DepartmentHuaqiao UniversityXiamen 361021FujianChina Department of Materials Science and Engineering College of MaterialsXiamen UniversityXiamen 361005FujianChina College of Materials Science and Engineering Huaqiao UniversityXiamen 361021FujianChina College of Chemical Engineering Huaqiao UniversityXiamen 361021FujianChina Chemical Engineering UC San DiegoLa JollaCA 92093United States School of Chemistry and Chemical Engineering Jishou UniversityJishou 416000HunanChina

Metal-based core-shell nanostructures have garnered enduring interest due to their unique properties and ***,their growth and transformation mechanisms in liquid media remain largely unknown because they lack direct observation of the dynamic growth process with high spatial and temporal *** the in situ liquid cell transmission electron microscopy(TEM)technique offers unprecedented real-time imaging and spectroscopy capabilities to directly track the evolution of structural and chemical transformation of metal-based core–shell nanostructures in liquid media under their working ***,this review highlights recent progress in utilizing in situ liquid cell TEM characterization technique in investigating the dynamic evolution of material structure and morphology of metal-based core–shell nanostructures at the nano/atomic scale in real-time.A brief introduction of the development of liquid cells for in situ TEM is first ***,recent advances in in situ liquid cell TEM for the fundamental study of growth mechanisms of metal based core–shell nanostructures are ***,the challenge and future developments of metalbased core–shell nanostructures for in situ liquid cell TEM are *** review is anticipated to inspire ongoing interest in revealing unseen growth dynamics of core–shell nanostructures by in situ liquid cell TEM technique.

关键词： In situ liquid cell TEM Metal-based core–shell nanostructures Growth mechanisms

Decision Intelligence Empowered Resource Management for 6G Vehicle-to-Everything Communications

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2023年

作者： zhao junhui NIE Yiwen ZHANG Huan WANG Dongming East China Jiaotong University Lenovo Research Beijing Jiaotong University Southeast University

To meet more requirements for the future communications, the sixth generation(6G) wireless communication networks are expected to provide the better coverage, spectra/energy efficiency, intelligence, and security than the fifth generation(5G) networks. With the recent advances in artificial intelligence(AI), the 6G vehicle-to-everything(V2X) focus on the further AI applications for intelligent transportation systems(ITS), especially for extending decision intelligence(DI) of resource management. Specifically, a new V2X framework integrated 6G techniques and AI approaches is proposed in this article. We introduce some typical 6G techniques to assist the vehicular intelligence as alternative ***, we provide the intelligent resource managements based on edge intelligence, integrated intelligence,distributed intelligence, and secure intelligence to overcome challenges of efficiency, delay, mobility, and privacy,respectively. We also propose a federated reinforcement learning(FRL) based algorithm to validate the privacyaware secure intelligence with effective resource management. Simulation results show that the proposed algorithm significantly outperforms the non-AI baseline schemes in the novel network structure. To enlighten future topics for 6G vehicular resource management, we discuss some potential scenarios with the promising AIbased solutions.

关键词：

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

云杉种植管理与栽培技术要点

广东蚕业 2024年第2期58卷 77-79页

作者：赵军辉察哈尔右翼后旗当郎忽洞苏木人民政府内蒙古乌兰察布012411

云杉是一种常见且重要的针叶树种,在园林绿化、木材生产等方面应用广泛。为了保证云杉的正常生长,合理的种植管理与栽培技术非常关键。文章立足于云杉的特征和用途,介绍了云杉种植管理的技术要点,包括种植场地选择、种子和苗木选择、栽... 详细信息

云杉是一种常见且重要的针叶树种,在园林绿化、木材生产等方面应用广泛。为了保证云杉的正常生长,合理的种植管理与栽培技术非常关键。文章立足于云杉的特征和用途,介绍了云杉种植管理的技术要点,包括种植场地选择、种子和苗木选择、栽植技术以及水肥管理等,总结了云杉栽培的技术要点,包括土壤准备、定期修剪、种植密度控制以及病虫害防治等,以期为云杉的种植和养护及相关行业发展提供指导。

关键词：云杉种植管理栽培技术技术要点