检索结果-南通市图书馆

Dementia in military and veteran populations:a review of risk factors—traumatic brain injury,post-traumatic stress disorder,deployment,and sleep

在线全文

学校读者我要写书评

暂无评论

Military Medical Research 2022年第3期9卷 351-364页

作者： Zara Raza Syeda F.Hussain Suzanne Ftouni Gershon Spitz Nick Caplin Russell G.Foster Renata S.M.Gomes Research and Innovation Blind Veterans UK12-14 Harcourt StreetLondonW1H 4HDUK BRAVO VICTOR Research12-14 Harcourt StreetLondonW1H 4HDUK Circadian Therapeutics OxfordOX11BYUK School of Psychological Sciences Monash University18 Innovation WalkClayton CampusWellington RoadMelbourneVIC3800Australia Sleep&Circadian Neuroscience Institute(SCNi) Nuffield Department of Clinical NeurosciencesSir William Dunn School of PathologyOxford Molecular Pathology InstituteUniversity of OxfordSouth Parks RoadOxfordOX13RFUK Northern Hub for Veterans and Military Families Research Department of NursingMidwifery and HealthFaculty of Health and Life SciencesNorthumbria UniversityNewcastleNE77XAUK

The military population face a unique set of risk factors that may increase the risk of being diagnosed with dementia.Traumatic brain injury(TBI)and post-traumatic stress disorder(PTSD)have a higher prevalence in this group in comparison to the civilian population.By delving into the individual relationships between TBI and dementia,and PTSD and dementia,we are able to better explore dementia in the military and veteran populations.While there are some inconsistencies in results,the TBI-dementia association has become more widely accepted.Moderate-tosevere TBI has been found to increase the risk of being diagnosed with Alzheimer’s disease.A correlation between PTSD and dementia has been established,however,whether or not it is a causal relationship remains unclear.Factors such as blast,combat and chemical exposure may occur during a deployment,along with TBI and/or PTSD diagnosis,and can impact the risk of dementia.However,there is a lack of literature exploring the direct effects of deployment on dementia risk.Sleep problems have been observed to occur in those following TBI,PTSD and deployment.Poor sleep has been associated with possible dementia risk.Although limited studies have focused on the link between sleep and dementia in military and veteran populations,sleep is a valuable factor to study due to its association and interconnection with other military/veteran factors.This review aims to inform of various risk factors to the cognitive health of military members and veterans:TBI,PTSD,deployment,and sleep.

关键词： Dementia Alzheimer’s disease Traumatic brain injury Post-traumatic stress disorder Military Veteran deployment Sleep

Dynamics and rebound behavior analysis of flexible tethered satellite system in deployment and station-keeping phases

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2022年第3期18卷 509-523页

作者： Yue Zhang Xin Jiang Zheng-feng Bai Jia-wen Guo Cheng Wei School of Space Science and Technology Xidian UniversityXi'an710126China School of Astronautics Harbin Institute of TechnologyHarbin150001China Department of Mechanical Engineering Harbin Institute of TechnologyWeihai264209China

The tether deployment of a tethered satellite system involves the consideration of complex dynamic properties of the tether,such as large deformation,slack,and even rebound,and therefore,the dynamic modelling of the tether is necessary for performing a dynamic analysis of the system.For a variablelength tether element,the absolute nodal coordinate formulation(ANCF)in the framework of the arbitrary Lagrange-Euler(ALE)description was used to develop a precise dynamic model of a tethered satellite.The model considered the gravitational gradient force and Coriolis force in the orbital coordinate frame,and it was validated through numerical simulation.In the presence of dynamic constraints,a deployment velocity of the tether was obtained by an optimal procedure.In the simulation,rebound behavior of the tethered satellite system was observed when the ANCF-ALE model was employed.Notably,the rebound behavior cannot be predicted by the traditional dumbbell model.Furthermore,an improved optimal deployment velocity was developed.Simulation results indicated that the rebound phenomenon was eliminated,and smooth deployment as well as a stable state of the station-keeping process were achieved.Additionally,the swing amplitude in the station-keeping phase decreased when a deployment strategy based on the improved optimal deployment velocity was used.

关键词： Tethered satellite system Dynamic model Rebound deployment ANCF-ALE

Optimal deployment of Heterogeneous Nodes to Enhance Network Invulnerability

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第11期73卷 3081-3097页

作者： Qian Sun Fengbo Yang Xiaoyi Wang Jiping Xu Huiyan Zhang Li Wang Jiabin Yu Xiao Peng Ruichao Wang School of Artificial Intelligence Beijing Technology and Business UniversityBeijing100048China Beijing Laboratory for Intelligent Environmental Protection Beijing100048China Beijing Institute of Fashion Technology Beijing100029China University College Dublin Dublin4Ireland

Wireless sensor networks(WSN)can be used in many fields.In wireless sensor networks,sensor nodes transmit data in multi hop mode.The large number of hops required by data transmission will lead to unbalanced energy consumption and large data transmission delay of the whole network,which greatly affects the invulnerability of the network.Therefore,an optimal deployment of heterogeneous nodes(ODHN)algorithm is proposed to enhance the invulnerability of the wireless sensor networks.The algorithm combines the advantages of DEEC(design of distributed energy efficient clustering)clustering algorithm and BAS(beetle antenna search)optimization algorithm to find the globally optimal deployment locations of heterogeneous nodes.Then,establish a shortcut to communicate with sink nodes through heterogeneous nodes.Besides,considering the practical deployment operation,we set the threshold of the mobile location of heterogeneous nodes,which greatly simplifies the deployment difficulty.Simulation results show that compared with traditional routing protocols,the proposed algorithm can make the network load more evenly,and effectively improve energy-utilization and the fault tolerance of the whole network,which can greatly improve the invulnerability of the wireless sensor networks.

关键词： Wireless sensor networks invulnerability small world characteristic heterogeneous node deployment

Review of deployment technology for tethered satellite systems

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

Acta Mechanica Sinica 2018年第4期34卷 754-768页

作者： B.S.Yu H.Wen D.P.Jin State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics

Tethered satellite systems（TSSs） have attracted significant attention due to their potential and valuable applications for scientific research. With the development of various launched on-orbit missions, the deployment of tethers is considered a crucial technology for operation of a TSS. Both past orbiting experiments and numerical results have shown that oscillations of the deployed tether due to the Coriolis force and environmental perturbations are inevitable and that the impact between the space tether and end-body at the end of the deployment process leads to complicated nonlinear phenomena. Hence, a set of suitable control methods plays a fundamental role in tether deployment. This review article summarizes previous work on aspects of the dynamics, control, and ground-based experiments of tether deployment. The relevant basic principles, analytical expressions, simulation cases, and experimental results are presented as well.

关键词： Tethered satellite deployment Dynamics Control Experiment

deployment Reliability Test and Assessment for Landing Gear of Chang' E-3 Probe

在线全文

学校读者我要写书评

暂无评论

Journal of Donghua University(English Edition) 2014年第6期31卷 782-784,800页

作者：吴琼杨建中傅惠民徐青华满剑锋 Institute of Spacecraft System Engineering China Academy of Space Technology College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Research Center of Small Sample Technology Beijing University of Aeronautics and Astronautics

Chang'E-3 probe incorporates four landing gears to assure the soft-landing,which are stowed while launching and deployed after separated from rocket. deployment reliability is quite crucial for this mission. The deployment reliability test( DRT) method and assessment method were developed in this paper. Then DRT was conducted and the deployment reliability estimate of Chang'E-3probe was used to verify the proposed methods.

关键词： Chang’E-3 landing gear deployment reliability test assessment

System deployment and decentralized control of islanded AC microgrids without communication facility

在线全文

学校读者我要写书评

暂无评论

Journal of Modern Power Systems and Clean Energy 2019年第4期7卷 913-922页

作者： Baoquan LIU School of Electrical and Information Engineering Shaanxi University of Science and TechnologyXi’an 710021China

This paper proposes a novel system deployment principle for master/slave islanded alternating current(AC)microgrids,with which decentralized control can be achieved without communications.The net power of a microgrid,including active and reactive power,is metered and compensated locally and independently by its units.This can benefit a microgrid regarding system expandability,flexibility,and plug-and-play.The proposed strategy is demonstrated in a typical islanded AC microgrid with diesel generators,renewable generation,and hybrid storage.A diesel generator set with constant speed governor and static exciter runs to build up and dominate the main AC bus.An ultra-capacitor unit suppresses fastvarying power fluctuations,and the battery shares part of the slow-varying power component.The diesel generator set only provides slow-varying power within a lower limit,which can avoid dramatic accelerations and decelerations and low load-rate operation.Finally,simulations on MATLAB/Simulink are carried out to verify the proposed strategy in typical scenarios.

关键词： System deployment Decentralized control AC microgrid Diesel Hybrid storage

Fault-tolerant feedback virtual machine deployment based on user-personalized requirements

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2018年第4期12卷 682-693页

作者： Shukun LIU Weijia JIA Xianmin PAN Department of Information Technology Hunan Women's University Changsha 410004 China Faculty of Science and Technology University of Macao Macao 999078 China

A key requirement of the cloud platform is the reasonable deployment of its large-scale virtual machine infrastructure. The mapping relation between the virtual node and the physical node determines the specific resource distribution strategy and reliability of the virtual machine deployment. Resource distribution strategy has an important effect on performance, energy consumption, and guarantee of the quality of service of the computer, and serves an important role in the deployment of the virtual machine. To solve the problem of meeting the fault-tolerance requirement and guarantee high reliability of the application system based on the full use of the cloud resource under the prerequisite of various demands, the deployment framework of the feedback virtual machine in cloud platform facing the individual user＇s de- mands of fault-tolerance level and the corresponding deploy- ment algorithm of the virtual machine are proposed in this paper. Resource distribution strategy can deploy the virtual machine in the physical nodes where the resource is mutu- ally complementary according to the users＇ different require- ments on virtual resources. The deployment framework of the virtual machine in this paper can provide a reliable com- puter configuration according to the specific fault-tolerance requirements of the user while considering the usage rate of the physical resources of the cloud platform. The experimental result shows that the method proposed in this paper can provide flexible and reliable select permission of faulttolerance level to the user in the virtual machine deployment process, provide a pertinent individual fault-tolerant deployment method of the virtual machine to the user, and guarantee to meet the user service in a large probability to some extent.

关键词： virtual machine feedback fault-tolerance deployment

Dynamic analysis of spinning solar sails at deployment process

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 2017年第5期30卷 1719-1728页

作者： Xinxing ZHANG Chunyan ZHOU School of Aerospace Engineering Beijing Institute of Technology Beijing 100081 China

The spinning deployment process of solar sails is analyzed in this study. A simplified model is established by considering the out-of-plane and in-plane motions of solar sails. The influences of structure parameters, initial conditions, and feedback control parameters are also analyzed.A method to build the geometric model of a solar sail is presented by analyzing the folding process of solar sails. The finite element model of solar sails is then established, which contains continuous cables and sail membranes. The dynamics of the second-stage deployment of solar sails are simulated by using ABAQUS software. The influences of the rotational speed and out-of-plane movement of the hub are analyzed by different tip masses, initial velocities, and control parameters.Compared with the results from theoretical models, simulation results show good agreements.

关键词： deployment Dynamics Solar sail Spinning Stability

Optimized deployment of a radar network based on an improved firefly algorithm

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2019年第3期20卷 425-437页

作者： Xue-jun ZHANG Wei JIA Xiang-min GUAN Guo-qiang XU Jun CHEN Yan-bo ZHU National Key Laboratory of CNS/ATM School of Electronic and Information EngineeringBeihang University Department of General Aviation Civil Aviation Management Institute of China Lincoln School of Engineering University of LincolnBrayford Pool Campus

The threats and challenges of unmanned aerial vehicle(UAV) invasion defense due to rapid UAV development have attracted increased attention recently. One of the important UAV invasion defense methods is radar network detection. To form a tight and reliable radar surveillance network with limited resources, it is essential to investigate optimized radar network deployment. This optimization problem is difficult to solve due to its nonlinear features and strong coupling of multiple constraints. To address these issues, we propose an improved firefly algorithm that employs a neighborhood learning strategy with a feedback mechanism and chaotic local search by elite fireflies to obtain a trade-off between exploration and exploitation abilities. Moreover, a chaotic sequence is used to generate initial firefly positions to improve population diversity. Experiments have been conducted on 12 famous benchmark functions and in a classical radar deployment scenario. Results indicate that our approach achieves much better performance than the classical firefly algorithm(FA) and four recently proposed FA variants.

关键词： Improved firefly algorithm Radar surveillance network deployment optimization Unmanned aerial vehicle (UAV) invasion defense