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A Single-Site Positioning Method Based on TOA and DOA Estimation Using Virtual Stations in NLOS Environment

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China Communications 2019年第2期16卷 146-159页

作者： Rui Zhang weiwei xia Feng Yan Lianfeng Shen National Mobile Communications Research Laboratory Southeast University

This paper presents a single-site positioning method based on the joint estimation of propagation time-of-arrival(TOA) and direction-of-arrival(DOA), with the assist of virtual stations in the typical non-line-of-sight(NLOS) environment. Consider the influence of multipath noise on the positioning performance, the proposed method firstly presents a modified high-resolution estimation technique called Multipath noise Limiting Matrix Pencil(MLMP) algorithm to achieve the TOA/DOA estimations, in which the matrix pencil and matrix enhancement process are implemented to deal with the measurements from the uniform linear array(ULA) receiver. Meanwhile, the subspace dimension estimation is improved via an adaptive threshold, for enhancing the performance of high-resolution techniques in low signal-noise-ration(SNR) situation. Next the proposed method generates virtual stations utilizing the known floor plan of surrounding reflectors, and adopts a weighted Least Square(WLS) position estimator to calculate the required position, combining the TOA/DOA estimations with the location of virtual stations. Simulations are conducted to evaluate the proposed method under NLOSconditions, and the results show that comparing with the multipath fingerprinting scheme, the proposed method has better performance in various simulation scenarios.

关键词： single-site positioning TOA DOA NLOS virtual station

A NOVEL CALL ADMISSION CONTROL SCHEME IN CELLULAR/WLAN INTEGRATION AND PERFORMANCE ANALYSIS

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Journal of Electronics(China) 2009年第2期26卷 168-178页

作者： xia weiwei Shen Lianfeng National Mobile Communications Research Lab Southeast University Nanjing 210096 China

In order to achieve the Quality of Service(QoS) provisioning and efficient resource utili-zation in cellular network and Wireless Local Area Network(WLAN) integration,an Integrated Ser-vice-Based Call Admission Control(ISB-CAC) scheme is proposed in this *** integrated network is modeled by using multi-dimensional Markov *** numerical analysis is presented to evaluate the important performance measures such as the blocking probability of originating calls,the dropping probability,and the average transfer time,*** steady-state probabilities of the multi-dimensional Markov chains are obtained by using an iterative approach,and the CAC pa-rameters are optimally *** analytical model is validated by the computer *** is shown that compared with the conventional WLAN-First Call Admission Control(WF-CAC) scheme,the proposed ISB-CAC scheme not only provides better QoS for mobile users but also utilizes the bandwidth resources more efficiently.

关键词： Cellular/WLAN integration Call Admission Control(CAC) Quality of Service(QoS) Vertical handoff Markov process

Differential protein expression in spinal cord tissue of a rabbit model of spinal cordischemia/reperfusion injury

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Neural Regeneration Research 2012年第20期7卷 1534-1539页

作者： Qi Gao Yonghui Liang xiaoyu Yang Guifeng Liu xiaoxue Li Benqing Zhu Jian Liu Maoguang Yang weiwei xia Jian Dong Jianhang Jiao Team of Spine and Spinal Cord Department of OrthopedicsChina-Japan Friendship HospitalJilin UniversityChangchun 130033JilinProvinceChina

New Zealand rabbits were randomly divided into an ischemia group （occlusion of the abdominal aorta for 60 minutes）, an ischemia-reperfusion group （occlusion of the abdominal aorta for 60 minutes followed by 48 hours of reperfusion） and a sham-surgery group. Two-dimensional gel electrophoresis detected 49 differentially expressed proteins in spinal cord tissue from the ischemia and ischemia/ reperfusion groups and 23 of them were identified by mass spectrometry. In the ischemia group, the expression of eight proteins was up regulated, and that of the remaining four proteins was down regulated. In the ischemia/reperfusion group, the expression of four proteins was up regulated, and that of two proteins was down regulated. In the sham-surgery group, only one protein was detected. In the ischemia and ischemia/reperfusion groups, four proteins overlapped between groups with the same differential expression, including three that were up regulated and one down regulated. These proteins were related to energy metabolism, cell defense, inflammatory mechanism and cell signaling.

关键词： spinal cord injury ischemia/reperfusion two-dimensional gel electrophoresis mass spectrometry rabbit proteomics neural regeneration

Evidence for niche differentiation of nitrifying communities in grassland soils after 44 years of different field fertilization scenarios

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Pedosphere 2020年第1期30卷 87-97页

作者： Zhongjun JIA Xue ZHOU weiwei xia Dario FORNARA Baozhan WANG Elizabeth Anne WASSON Peter CHRISTIE Martin F.POLZ David D.MYROLD State Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098(China) Jiangsu Key Laboratory of Agricultural Meteorology College of Applied MeteorologyNanjing University of Information Science and TechnologyNanjing 210044(China Agri-Food and Biosciences Institute Belfast BT95PX(UK) Department of Civil and Environmental Engineering Massachusetts Institute of TechnologyCambridge MA 02139(USA) Department of Crop and Soil Science Oregon State UniversityCorvallis OR 97331(USA)

Long-term nitrogen(N)fertilization imposes strong selection on nitrifying communities in agricultural soil,but how a progressively changing niche affects potentially active nitrifiers in the field remains poorly *** a 44-year grassland fertilization experiment,we investigated community shifts of active nitrifiers by DNA-based stable isotope probing(SIP)of field soils that received no fertilization(CK),high levels of organic cattle manure(HC),and chemical N fertilization(CF).Incubation of DNA-SIP microcosms showed significant nitrification activities in CF and HC soils,whereas no activity occurred in CK *** 44 years of inorganic N fertilization selected only 13C-ammonia-oxidizing bacteria(AOB),whereas cattle slurry applications created a niche in which both ammonia-oxidizing archaea(AOA)and AOB could be *** analysis indicated that Nitrosospira sp.62-like AOB dominated inorganically fertilized CF soils,while Nitrosospira sp.41-like AOB were abundant in organically fertilized HC *** 13C-AOA in HC soils were affiliated with the 29i4 *** 13C-nitrite-oxidizing bacteria(NOB)were dominated by both Nitrospira-and Nitrobacter-like communities in CF soils,and the latter was overwhelmingly abundant in HC *** 13C-labeled nitrifying communities in SIP microcosms of CF and HC soils were largely similar to those predominant under field *** results provide direct evidence for a strong selection of distinctly active nitrifiers after 44 years of different fertilization regimes in the *** findings imply that niche differentiation of nitrifying communities could be assessed as a net result of microbial adaption over 44 years to inorganic and organic N fertilization in the field,where distinct nitrifiers have been shaped by intensified anthropogenic N input.

关键词： ammonia-oxidizing archaea ammonia-oxidizing bacteria community shift long-term fertilization nitrite-oxidizing bacteria nitrogen enrichment stable isotope probing microcosm

Surgical instruments hyalinization:Occlusion removal in minimally invasive endoscopic surgery

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Biomimetic Intelligence & Robotics 2023年第3期3卷 1-8页

作者： Dongsheng Xie Wenxin Chen Jin Zhao Xinya Song Kaifeng Wang weiwei xia Haiying Liu Fangle Chang Changsheng Li Xingguang Duan School of Medical Technology Beijing Institute of TechnologyBeijing 100081China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China Department of Spinal Surgery Peking University People’s HospitalBeijing 100044China Ningbo Innovation Center Zhejiang UniversityNingBo 315100China

Minimal invasion is an important trend in ***,the endoscope,as one of the key devices for monitoring the process of minimally invasive surgery,is limited by its size and working space it operates in,which result in a considerably narrow field of *** particular,when a surgical instrument enters through the tool channel,the instrument occupies most of the area in an endoscopic *** hampers the surgeon’s field of view and has a negative impact on the *** study proposes a novel method for removing the occlusion caused by surgical instruments in endoscopic images by making foreground occlusions on endoscopic images transparent using image restoration and interframe information *** with unprocessed images,this method can provide a clearer field of view that is necessary for minimally invasive endoscopic surgeries and improve the quality of *** endoscopic images are used to verify the feasibility of the proposed method,and the results show that the proposed method improves the visual effect of endoscopic images by removing surgical-instrument *** demonstrates the considerable potential of the proposed method for use in clinical applications.

关键词： Image inpainting Minimally invasive endoscopic surgery Occlusion removal

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一种基于模糊神经网络的异构网络选择算法

东南大学学报（自然科学版） 2010年第4期40卷 663-669页

作者：夏玮玮沈连丰东南大学移动通信国家重点实验室南京210096

提出了应用于异构网络融合场景的基于模糊神经网络的网络选择算法.该算法由预判决、模糊神经网络处理和网络选择判决3个模块组成.引入预判决模块,滤除了能直接进行网络选择的采样点,减少了进入模糊神经网络的采样点数;模糊神经网络处理... 详细信息

提出了应用于异构网络融合场景的基于模糊神经网络的网络选择算法.该算法由预判决、模糊神经网络处理和网络选择判决3个模块组成.引入预判决模块,滤除了能直接进行网络选择的采样点,减少了进入模糊神经网络的采样点数;模糊神经网络处理模块综合考虑信号强度、终端移动速度以及网络带宽等因素来进行网络选择判决;由于模糊神经网络具有学习训练能力,故能根据输出误差自适应调整隶属度函数的参数.仿真结果表明:提出的算法在保证较低丢包率的情况下,有效降低了网络选择判决时延,减少了乒乓效应的发生次数,降低了阻塞率.

关键词：异构网络网络选择模糊神经网络预判决

Incidence,prevalence,and causes of spinal injuries in China,1990-2019:Findings from the Global Burden of Disease Study 2019

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Chinese Medical Journal 2024年第6期137卷 704-710页

作者： Chenjun Liu Tingling Xu weiwei xia Shuai Xu Zhenqi Zhu Maigeng Zhou Haiying Liu Department of Spinal Surgery Peking University People’s HospitalPeking UniversityBeijing 100044China Chinese Preventive Medicine Association Committee on Prevention and Control of Spinal DiseaseBeijing 100009China National Center for Chronic and Noncommunicable Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijing 100050China School of Public Health Xi’an Jiaotong UniversityXi’anShaanxi 710061China

Background:Spinal injuries are an urgent public health priority;nevertheless,no China-wide studies of these injuries *** study measured the incidence,prevalence,causes,regional distribution,and annual trends of spinal injuries in China from 1990 to ***:We used data from the Global Burden of Diseases,Injuries,and Risk Factors Study 2019 to estimate the incidence and prevalence of spinal injuries in *** data of 33 provincial-level administrative regions(excluding Taiwan,China)provided by the National Center for Chronic and Noncommunicable Disease Control and Prevention,Chinese Center for Disease Control and Prevention(CDC)were use to systematically analyze the provincial etiology,geographical distribution,and annual trends of spinal *** Bayesian meta-regression tool DisMod-MR 2.1 was used to ensure the consistency among incidence,prevalence,and mortality rates in each ***:From 1990 to 2019,the number of living patients with spinal injuries in China increased by 138.32%,from 2.14 million to 5.10 million,while the corresponding age-standardized prevalence increased from 0.20%(95%uncertainty interval[UI]:0.18-0.21%)to 0.27%(95%UI:0.26-0.29%).The incidence of spinal injuries in China increased by 89.91%(95%UI:72.39-107.66%),and the prevalence increased by 98.20%(95%UI:89.56-106.82%),both the most significant increases among the G20 countries;71.00%of the increase could be explained by age-specific *** 2019,the incidence was 16.47(95%UI:12.08-22.00,per 100,000 population),and the prevalence was 358.30(95%UI:333.96-386.62,per 100,000 population).Based on the data of 33 provincial-level administrative regions provided by CDC,age-standardized incidence and prevalence were both highest in developed provinces in Eastern *** primary causes were falls and road injuries;however,the prevalence and specific causes differed across ***:In China,the overall disease burden of spinal injuries increased significantl

关键词： Spinal injuries Global Burden of Diseases,Injuries and Risk Factors Study 2019 Incidence Prevalence Falls Road injuries

In situ atomic-scale observation of size-dependent (de) potassiation and reversible phase transformation in tetragonal FeSe anodes

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InfoMat 2023年第1期5卷 161-171页

作者： Ran Cai Lixia Bao Wenqi Zhang weiwei xia Chunhao Sun Weikang Dong xiaoxue Chang Ze Hua Ruiwen Shao Toshio Fukuda Zhefei Sun Haodong Liu Qiaobao Zhang Feng Xu Lixin Dong Beijing Advanced Innovation Center for Intelligent Robots and Systems School of Medical TechnologyBeijing Institute of TechnologyBeijingPeople's Republic of China Analysis&Testing Center Beijing Institute of TechnologyBeijingPeople's Republic of China Department of Biomedical Engineering City University of Hong KongHong KongPeople's Republic of China Shaanxi Materials Analysis and Research Center School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'anPeople's Republic of China School of Environmental and Safety Engineering North University of ChinaTaiyuanPeople's Republic of China Department of Materials Science and Engineering College of MaterialsXiamen UniversityXiamenFujianPeople's Republic of China Department of Nanoengineering University of California San DiegoLa JollaCaliforniaUSA SEU-FEI Nano-Pico Center Key Laboratory of MEMS of Ministry of EducationSoutheast UniversityNanjingPeople's Republic of China

Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the exploration of appro-priate electrode materials with the correct size for reversibly accommodating large K+ions presents a significant *** addition,the reaction mecha-nisms and origins of enhanced performance remain ***,tetragonal FeSe nanoflakes of different sizes are designed to serve as an anode for PIBs,and their live and atomic-scale potassiation/depotassiation mechanisms are revealed for the first time through in situ high-resolution transmission electron *** found that FeSe undergoes two distinct structural evolutions,sequen-tially characterized by intercalation and conversion reactions,and the initial intercalation behavior is *** expansion induced by the intercalation of K+ions is observed in small-sized FeSe nanoflakes,whereas unexpected cracks are formed along the direction of ionic diffusion in large-sized *** significant stress generation and crack extension originating from the combined effect of mechanical and electrochemical interactions are elucidated by geometric phase analysis and finite-element *** the different intercalation behaviors,the formed products of Fe and K_(2)Se after full potassiation can be converted back into the original FeSe phase upon *** particular,small-sized nanoflakes exhibit better cycling perfor-mance with well-maintained structural *** article presents the first successful demonstration of atomic-scale visualization that can reveal size-dependent potassiation ***,it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs.

关键词： elucidated by geometric phase analysis and finite-element analysis. Despite the different intercalation behaviors the formed products of Fe and K 2 Se after full potassiation can be converted back into the original FeSe phase upon depotassiation. In particular small-sized nanoflakes exhibit better cycling perfor- mance with well-maintained structural integrity. This article presents the first successful demonstration of atomic-scale visualization that can reveal size- dependent potassiation dynamics. Moreover it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs. KEYWOR DS in situ transmission electron microscopy potassium-ion batteries potassium-ion storage mechanism size-dependent effects tetragonal FeSe

A movement-assisted software-defined sensor network with NFV support

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Journal of Southeast University(English Edition) 2018年第2期34卷 156-165页

作者： Yin Haohao Ding Cui Yan Feng xia weiwei Shen Lianfeng National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China

A flexible and controllable movement-assisted software-defined sensor network(MA-SDSN)based on the software-defined network(SDN)and network function virtualization(NFV)is ***,a three-layer fundamental architecture is proposed to overcome the inherent distributed management and rigidity of the conventional wireless sensor ***,the platform for research and development of MA-SDSN is established,and the dumb node(DN),the software-defined node(SN)and the movement-assisted node(MN)are designed and ***,the southbound application programming interface(API)is designed to provide a series of frames for communication between controllers and sensor *** northbound API is developed and demonstrated overall and in *** functions of the controller are presented including topology discovery,dynamic networking,packet processing,mobility management and *** by the MA-SDSN network model,a Markov chain-based movement-assisted weighted relocation(MMWR)topology control algorithm is proposed to redeploy the MNs based on the node status and *** results and analysis indicate that the proposed algorithm based on the MA-SDSN extends network lifetime with a lower average power consumption.

关键词： software-defined sensor network network function virtualization movement-assisted topology control