检索结果-南通市图书馆

Multi-radio access based bandwidth allocation strategy for video communication in heterogeneous wireless 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

The Journal of China Universities of Posts and Telecommunications 2016年第2期23卷 6-14页

作者： zhu Xuewen zhu qi Jiangsu Key Laboratory of Wireless Communications Nanjing University of Posts and Telecommunications Key Laboratory on Wideband Wireless Communications and Sensor Network Technology Nanjing University of Posts and Telecommunications

In order to make full use of the radio resource of heterogeneous wireless networks（HWNs） and promote the quality of service（Qo S） of multi-homing users for video communication, a bandwidth allocation algorithm based on multi-radio access is proposed in this paper. The proposed algorithm adopts an improved distributed common radio resource management（DCRRM） model which can reduce the signaling overhead sufficiently. This scheme can be divided into two phases. In the first phase, candidate network set of each user is obtained according to the received signal strength（RSS）. And the simple additive weighted（SAW） method is employed to determine the active network set. In the second phase, the utility optimization problem is formulated by linear combining of the video communication satisfaction model, cost model and energy efficiency model. And finding the optimal bandwidth allocation scheme with Lagrange multiplier method and Karush-Kuhn-Tucker（KKT） conditions. Simulation results show that the proposed algorithm promotes the network load performances and guarantees that users obtain the best joint utility under current situation.

关键词： video communication heterogeneous wireless networks joint utility energy efficiency radio resource management

东南沿海部队训练伤发生的影响因素和损伤特征分析

在线全文

学校读者我要写书评

暂无评论

第三军医大学学报 2018年第19期40卷 1723-1728页

作者：王太武艾乐乐张琪丁晨曦朱长强叶福强杨露吕瑞辰谭伟龙王长军南京军区疾病预防控制中心南京210002

目的了解东南沿海部队训练伤发生现状和损伤特征,找出影响部队训练伤发生的独立危险因素。方法采用整群抽样的调查方法,抽取不同地区的7个中队(连)共433人为调查对象,采用问卷调查的方式回顾性调查研究对象的单位、年龄、BMI、人员类别... 详细信息

目的了解东南沿海部队训练伤发生现状和损伤特征,找出影响部队训练伤发生的独立危险因素。方法采用整群抽样的调查方法,抽取不同地区的7个中队(连)共433人为调查对象,采用问卷调查的方式回顾性调查研究对象的单位、年龄、BMI、人员类别、军种及既往抽烟、饮酒、睡眠、饮食和入伍前身体状况、训练时间等信息,了解训练伤的发生特征;通过多因素Logistic回归分析揭示训练伤发生的独立影响因素。结果调查共收集有效调查问卷417份,其中发生训练伤158份,过去1年训练伤发生率37. 89%。多因素Logistic回归分析显示单位、睡眠质量低、饮食结构不合理是训练伤发生的独立影响因素(P <0.05)。训练伤发生全年较为均衡,损伤部位主要在腰部和膝关节。引起训练伤的科目和官兵惧怕科目均为5公里武装越野训练、400米障碍训练和器械训练等;客观因素和主观心理因素对训练伤的发生均为重要影响因素。结论东南沿海部队训练伤发生率较高,高发单位、睡眠质量低、饮食结构不合理等人群是训练伤的易感人群,在预防训练伤时,应该加以重点预防与保护。

关键词：军事训练伤发生率影响因素 Logistic回归损伤特征

A New Fast Matching Algorithm by Trans-Scale Search for Remote Sensing Image

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2015年第3期24卷 654-660页

作者： qi Youjie zhu En College of Information Science and Engineering Southeast University

A new fast matching algorithm for remote sensing images is proposed. The algorithm adopts a coarse to fine matching process. A remote sensing image is decomposed into multi-scale images which form a wavelet image pyramid by the way of DWT(Discrete wavelet transform).Extract a low frequency sub-image from the wavelet image pyramid to carry out a rough matching operation between the sub-image and target image, and then get a rough position after cluster analysis. Get a suitable position with center at the rough position from remote sensing image to accomplish fine matching operation. The algorithm has been analyzed theoretically from the signal processing point of view, and a sufficient condition is given to select wavelet filter. Simulation results testify that proposed algorithm not only distinguishes remote sensing images precisely, but also cuts down matching time greatly. It is only 25.04% of SIFT algorithm, and 35.36% of SURF algorithm for matching time.

关键词： Image matching SIFT DWT Remote sensing

Time-Efficient Power Allocation Scheme for Two-Way Multi-relay Cognitive Radio Networks

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2016年第2期25卷 357-363页

作者： ZHOU Zhikang zhu qi The Key Wireless Lab of Jiangsu Province School of Telecommunication and Information EngineeringNanjing University of Posts and Telecommunications Key Lab on Wideband Wireless Communications and Sensor Network Technology of Ministry of Education

Cooperative relaying has been emerging as a key technology in Cognitive radio(CR) networks. A two-way Amplify-and-forward(AF) based multi-relay CR network is considered, where a primary user coexists with a pair of secondary users and multiple relays. A Timeefficient sub-optimal power allocation scheme(TESOPA)based on Cauchy-Schwarz inequality is provided to maximize the total end-to-end transmission rate of the secondary system. TESOPA is proposed under maximal transmission power constraints, while ensuring the quality of service of the primary user during the whole communication process. The computational complexity is sharply decreased by using the Cauchy-Schwarz inequality. Simulation results show that the proposed TESOPA scheme performs very close to the near-optimal Interior point method based power allocation(IPMPA), especially in interference dominant networks where interference constraints play a key role in determining power allocation results instead of maximal transmission power constraints.

关键词： Power allocation Relay network Cognitive radio Amplify-and-forward Two-way communication

A high-efficiency separation process of Fe and Zn from zinc-bearing dust by direct reduction

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 Iron and Steel Research International 2022年第10期29卷 1559-1572页

作者： ding-zheng Wang De-qing zhu Jian Pan Zheng-qi Guo Hong-yu Tian Yu-xiao Xue School of Minerals Processing and Bioengineering Central South UniversityChangsha410083HunanChina

It is urgent to dispose of zinc-bearing dust from steel plants,and direct reduction process is an effective method to remove hazardous metals and recycle iron from the *** reduction behavior of carbon-containing pellets which were made from three kinds of zinc-bearing dust was *** the pellets were reduced at 1200℃ for 50 min,the reduced pellets with cold compressive strength of 1164 N pellet−1 and Zn content<0.1 wt.%could be directly used as burden for improving the blast furnace operation without further *** results of isothermal kinetic study showed that the iron oxide reduction rate was controlled by the chemical *** strengthening mechanism of reduced pellets and iron oxide reduction mechanism was investigated by thermodynamic calculation besides X-ray diffraction,scanning electron microscopy combined with energy dispersive spectrometry,and optical microscopy *** was found that higher temperatures are required for the reduction of spinel phase(zinc ferrite)and olivine phase(hedenbergite).The generation and growth of metallic iron bridges could significantly increase the compressive strength of reduced *** iron oxide reduction in the carbon-containing pellets followed the uniform internal reduction model and possessed a high apparent reaction rate,which can improve energy utilization rate and production efficiency.

关键词： Zinc-bearing dust Reduction mechanism Kinetics High efficiency Direct reduction

ADAPTIVE SET STABILIZATION OF THE ATTITUDE OF A RIGID SPACECRAFT WITHOUT ANGULAR VELOCITY MEASUREMENTS

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

Journal of Systems Science & Complexity 2011年第1期24卷 105-119页

作者： Shihong ding Shihua LI qi LI School of Automation Southeast University Nanjing 210096 China College of Electrical and Information Engineering Jiangsu University Zhenjiang 212013 China School of Automation Southeast University Nanjing 210096 China

The global adaptive set stabilization problem of the attitude of a rigid spacecraft is addressed in this paper. Two different cases are considered. First, by using adaptive backstepping method, the authors design a global adaptive control law for the attitude control system with unknown inertia matrix such that the attitude and the angular velocities can be globally asymptotically stabilized to a set consisting of two equilibria. And then, based on the obtained backstepping adaptive law, the authors consider the case that the angular velocities are not measurable. By introducing an auxiliary state, a semi-global adaptive set stabilization law without angular velocity measurements is also designed. It is rigorously proved that, for the two cases, both of the closed loop systems satisfy the set stability. The effectiveness of the proposed methods is verified by simulation results.

关键词： Adaptive control attitude stabilization backstepping quaternion spacecraft.

Time-triggered State-machine Reliable Software Architecture for Micro Turbine Engine Control

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 Aeronautics 2012年第6期25卷 839-845页

作者： ZHANG qi XU Guoqiang ding Shuiting School of Transportation Science and Technology Beihang University Beijing 100191 China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Beihang University Beijing 100191 China

Time-triggered （TT） embedded software pattern is well accepted in aerospace industry for its high reliability. Fi-nite-state-machine （FSM） design method is widely used for its high efficiency and predictable behavior. In this paper, the time-triggered and state-machine combination software architecture is implemented for a 25 kg thrust micro turbine engine （MTE） used for unmanned aerial vehicle （UAV） system; also model-based-design development workflow for airworthiness software directive DO-178B is utilized. Experimental results show that time-triggered state-machine software architecture and development method could shorten the system development time, reduce the system test cost and make the turbine engine easily comply with the airworthiness rules.

关键词： airworthiness time-triggered finite-state-machine model-based-design turbine engine control

Adaptive sampling for corrugated plate digitization using a laser displacement sensor

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第5期67卷 1510-1523页

作者： WU ChengXing qi qi CHEN BaiJin YANG JiXiang ding Han State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Intelligent Manufacturing Equipment and Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China

The surface quality of a corrugated plate directly determines the heat transfer property of the thermal power mechanical *** detection methods are impractical for real-world production,being slow and *** contrast,the point laser displacement sensor,employing the optical triangle method,emerges as a promising device for assessing parts with variable curvature and highly reflective *** its benefits,high-density sampling by an innate frequency introduces challenges such as data redundancy and a poor signal-to-noise ratio,potentially affecting the efficiency and precision of subsequent data *** address these challenges,adjustable frequency data sampling has been developed for this sensor,allowing adaptive sampling for corrugated plate *** process begins with surface digitization to extract discrete points,which are transformed into intersection curves using the B-spline fitting ***,dominant points are identified,considering multigeometric constraints for curvature and arch ***,the sampling signal is adjusted based on the distribution information of dominant *** results indicate that the proposed method effectively minimizes redundant sampling without compromising the accurate capture of essential geometric features.

关键词： corrugated plate laser displacement sensor adaptive sampling dominant point curvature arch height

The Data-Reusing MCC-Based Algorithm and Its Performance Analysis

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2016年第4期25卷 719-725页

作者： LIU Chunhui qi Yue ding Wenrui Research Institute of Unmanned Aerial Vehicle Beihang University State Key Laboratory of Virtual Reality Technology and System Beihang University

Maximum correntropy criterion(MCC)provides a robust optimality criterion for non-Gaussian signal *** this paper,the weight update equation of the conventional MCC-based adaptive filtering algorithm is modified by reusing the past K input vectors,forming a class of data-reusing MCC-based algorithm,called DRMCC *** with the conventional MCCbased algorithm,the DR-MCC algorithm provides a much better convergence performance when the input data is *** mean-square stability bound of the DRMCC algorithm has been studied *** both Gaussian noise case and non-Gaussian noise case,the expressions for the steady-state Excess mean square error(EMSE) of DR-MCC algorithm have been *** relationship between the data-reusing order and the steadystate EMSEs is also *** results are in agreement with the theoretical analysis.

关键词： Adaptive filtering Maximum correntropy criterion(MCC) Data-reusing Mean-square stability Steady-state excess mean square error