检索结果-南通市图书馆

Consensus-based decentralized clustering for cooperative spectrum sensing in cognitive radio networks

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2012年第28期57卷 3677-3683页

作者： WU QiHui DING GuoRu WANG JinLong LI XiaoQiang huang yuzhen Institute of Communications Engineering PLA University of Science and TechnologyNanjing 210007China

A large number of previous works have demonstrated that cooperative spectrum sensing(CSS) among multiple users can greatly improve detection ***,when the number of secondary users(SUs;i.e.,spectrum sensors) is large,the sensing overheads(e.g.,time and energy consumption) will likely be intolerable if all SUs participate in *** this paper,we proposed a fully decentralized CSS scheme based on recent advances in consensus theory and unsupervised learning *** only on iteratively information exchanges among one-hop neighbors,the SUs with potentially best detection performance form a cluster in an ad hoc *** SUs take charge of CSS according to an average consensus protocol and other SUs outside the cluster simply overhear the sensing *** comparison,we also provide a decentralized implementation of the existing centralized optimal soft combination(OSC) *** results show that the proposed scheme has detection performance comparable to that of the OSC scheme and outperforms the equal gain combination scheme and location-awareness ***,compared with the OSC scheme,the proposed scheme significantly reduces the sensing overheads and does not require a priori knowledge of the local received signal-to-noise ratio at each SU.

关键词：位置感知产业集群全分散无线电网络频谱基础等增益合并检测性能

Average Secrecy Capacity of the Reconfigurable Intelligent Surface-Assisted Integrated Satellite Unmanned Aerial Vehicle Relay Networks

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

Computer Modeling in Engineering & Sciences 2024年第2期138卷 1849-1864页

作者： Ping Li Kefeng Guo Feng Zhou XuelingWang yuzhen huang School of Information Technology Yancheng Institute of TechnologyYancheng224051China School of Space Information Space Engineering UniversityBeijing101407China Space E-Star Communication Technology Co. LtdNanjing210007China Academy of Military Sciences of PLA Beijing100097China

Integrated satellite unmanned aerial vehicle relay networks(ISUAVRNs)have become a prominent topic in recent *** paper investigates the average secrecy capacity(ASC)for reconfigurable intelligent surface(RIS)-enabled ***,an eve is considered to intercept the legitimate information from the considered secrecy ***,we get detailed expressions for the ASC of the regarded secrecy system with the aid of the reconfigurable ***,to gain insightful results of the major parameters on the ASC in high signalto-noise ratio regime,the approximate investigations are further gotten,which give an efficient method to value the secrecy *** last,some representative computer results are obtained to prove the theoretical findings.

关键词： Integrated satellite unmanned aerial vehicle relay networks reconfigurable intelligent surface average secrecy capacity(ASC) asymptotic ASC

Ergodic Capacity of NOMA-Based Overlay Cognitive Integrated Satellite-UAV-Terrestrial Networks

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

Chinese Journal of Electronics 2023年第2期32卷 273-282页

作者： GUO Kefeng LIU Rui DONG Chao AN Kang huang yuzhen ZHU Shibing College of Electronic and Information Engineering Nanjing University of Aeronautics and Astronautics School of Space Information Space Engineering University The Sixty-third Research Institute National University of Defense Technology Artificial Intelligence Research Center National Innovation Institute of Defense Technology

Satellite communication has become a popular study topic owing to its inherent advantages of high capacity, large coverage, and no terrain ***, it can be combined with terrestrial communication to overcome the shortcomings of current wireless communication, such as limited coverage and high *** recent years, the integrated satellite-unmanned aerial vehicle-terrestrial networks(IS-UAV-TNs) have aroused tremendous interests to effectively reduce the transmission latency and enhance quality-of-service with improved spectrum efficiency. However, the rapidly growing access demands and conventional spectrum allocation scheme lead to the shortage of spectrum resources. To tackle the mentioned challenge, the non-orthogonal multiple access(NOMA) scheme and cognitive radio technique are utilized in IS-UAV-TN, which can improve spectrum utilization. In our paper, the transmission capacity of an NOMA-enabled IS-UAV-TN under overlay mode is discussed, specifically, we derive the closed-form expressions of ergodic capacity for both primary and secondary networks. Besides, simulation results are provided to demonstrate the validity of the mathematical derivations and indicate the influences of critical system parameters on transmission performance. Furthermore, the orthogonal multiple access(OMA)-based scheme is compared with our NOMA-based scheme as a benchmark,which illustrates that our proposed scheme has better performance.

关键词： Fading channels NOMA Closed-form solutions Simulation Radio transmitters Quality of service Benchmark testing

Experimental Research of Pressure Distribution in the Casing of Inducer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Thermal Science 2009年第4期18卷 301-305页

作者： Wu yuzhen and huang HaoNational Engineering Research Center for Specific Pump and Valve Beijing,China,Zip:100076 Chief Engineer National Engineering Research Center for Specific Pump and Valve Beijing Beijing China 100076

In this paper the inducer of the advanced-researched pump is studied. During multi-rotation speed experimentwith the medium of water, the dynamic pressures near inducer casing are obtained by transducer at each measuringpoint mounted on the casing along the axial direction, both in the steady rotation speed period and the up anddown period. Bases on analyses, the regularity of the axial distribution of time averaged pressure and pressurepulsation amplitude, the connection between pressure pulsation frequency and rotation speeds, and the relationshipbetween the pressure pulsation amplitude and the site of inducer blade are obtained.

关键词： inducer pressure distribution pressure pulsation frequency

Joint Trajectory and Passive Beamforming Optimization in IRS-UAV Enhanced Anti-Jamming Communication Networks

在线全文

学校读者我要写书评

暂无评论

China Communications 2022年第5期19卷 191-205页

作者： Zhifeng Hou Jin Chen yuzhen huang Yijie Luo Ximing Wang Jiangchun Gu Yifan Xu Kailing Yao PLA Army Engineering University Nanjing 210007China Artificial Intelligence Research Center Defense Innovation InstituteBeijing 100166China School of Information and Communication Beijing University of Posts and TelecommunicationsBeijing 100876China College of Information and Communication National University of Defense TechnologyWuhan 430010China

This paper investigates the anti-jamming communication scenario where an intelligent reflecting surface(IRS)is mounted on the unmanned aerial vehicle(UAV)to resist the malicious jamming *** from existing works,we consider the dynamic deployment of IRS-UAV in the environment of the mobile user and unknown ***,a joint trajectory and passive beamforming optimization approach is proposed in the IRS-UAV enhanced *** detail,the optimization problem is firstly formulated into a Markov decision process(MDP).Then,a dueling double deep Q networks multi-step learning algorithm is proposed to tackle the complex and coupling decision-making ***,simulation results show that the proposed scheme can significantly improve the anti-jamming communication performance of the mobile user.

关键词： intelligent reflecting surface unmanned aerial vehicle deep reinforcement learning trajectory optimization

INSULATOR TO SUPERCONDUCTOR TRANSITION OF Pb DOPED 2201 SINGLE CRYSTAL IN Bi-SYSTEM BY OXYGEN DEFICIENCY

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1990年第11期7卷 526-528页

作者： LIU Yongqian huang yuzhen CHEN Liquan CHEN Hong LI Jianqi NI Yongming JIA Shunlian ZHAO Zhongxian Institute of Physics Academia SinicaBeijing 100080

Flux method was used to grow large 2201 single crystal in Bi-Sr-Cu *** as-grown crystal was nonsuperconductor and showed semiconductivity in resistivity *** it was reduced in flowing N_(2) at 570℃ and appropriate oxygen vacancies were induced,supcrconductivity with T_(c)^(on)=6K was *** great influence of oxygen deficience on 3uperconductivity is ***,the incorporation of Pb adjusted the modulation pattern.

关键词： curve oxide conductivity

On optimization of cooperative MIMO for underlaid secrecy Industrial 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

Frontiers of Information Technology & Electronic Engineering 2023年第2期24卷 259-274页

作者： Xinyao WANG Xuyan BAO yuzhen huang Zhong ZHENG Zesong FEI School of Information and Electronics Beijing Institute of TechnologyBeijing100081China China Academy of Information and Communications Technology Beijing100191China Academy of Military Sciences of PLA Beijing100091China

In this paper,physical layer security techniques are investigated for cooperative multi-input multi-output(C-MIMO),which operates as an underlaid cognitive radio system that coexists with a primary user(PU).The underlaid secrecy paradigm is enabled by improving the secrecy rate towards the C-MIMO receiver and reducing the interference towards the *** a communication model is especially suitable for implementing Industrial Internet of Things(IIoT)systems in the unlicensed spectrum,which can trade off spectral efficiency and information *** this end,we propose an eigenspace-adaptive precoding(EAP)method and formulate the secrecy rate optimization problem,which is subject to both the single device power constraint and the interference power *** precoder design is enabled by decomposing the original optimization problem into eigenspace selection and power allocation ***,the eigenvectors are adaptively selected by the transmitter according to the channel conditions of the underlaid users and the *** addition,a simplified EAP method is proposed for large-dimensional C-MIMO transmission,exploiting the additional spatial degree of freedom for a low-complexity secrecy precoder *** results show that by transmitting signal and artificial noise in the properly selected eigenspace,C-MIMO can eliminate the secrecy outage and outperforms the fixed eigenspace precoding ***,the proposed simplified EAP method for the large-dimensional C-MIMO can significantly improve the secrecy rate.

关键词： Cognitive radio network Physical layer security Cooperative multi-input multi-output(C-MIMO) Eigenspace-adaptive precoding Difference convex programming

PERIODIC TABLE OF CLIMATIC CHANGES

在线全文

学校读者我要写书评

暂无评论

海洋地质与第四纪地质 1992年第2期 47-51页

作者： Xu Qinqi(Institute of Vertebrate Paleontology and Paleoanihropology, Academia Sinica, Beijing, 100044, China)huang yuzhen(Beijing Municipal Computing Centre, Beijing, 100005, China)

The climate changed regularly in accordance with the variation of the average incoming solar radiation in the winter half-year of the northern hemisphere on the Earth’s surface in each oxygen isotopic stage (i. e. Di in Table 1) during the last 730,000 years. Many interesting phenomena of the nature may be explained with applications of these data.

关键词： astroclimatology oxygen isotopic stage the penultimate glacial Peking Man

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

警察体育基础课程模式改革的实验研究

首都体育学院学报 2012年第6期24卷 529-531页

作者：黄玉珍福建警察学院警体部福建福州350007

针对公安院校新生入学后普遍身体素质偏差,加之警察体育基础课课时少,训练内容、方法和手段单一等问题,福建警察学院警体部在进行"警察体育基础课"教学改革时,通过采用不同的课程模式进行综合试验比较,研究公安院校警体基础课程模式、... 详细信息

针对公安院校新生入学后普遍身体素质偏差,加之警察体育基础课课时少,训练内容、方法和手段单一等问题,福建警察学院警体部在进行"警察体育基础课"教学改革时,通过采用不同的课程模式进行综合试验比较,研究公安院校警体基础课程模式、内容优化,以及如何有效提高学生体能的途径与方法,在课程模式改革方面取得较显著的效果。

关键词：警察体育体育基础课程模式体育基础课