检索结果-南通市图书馆

Translational Neurodegeneration 2021年第3期10卷 359-366页

作者： Dongchao Shen Xunzhe Yang Yanying Wang di he Xiaohan Sun Zhengyi Cai Jinyue Li Mingsheng Liu Liying Cui Department of Neurology Peking Union Medical College HospitalBeijing 100730China Neuroscience Center Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100730China

Objectives:The aim of this study was to assess and compare the diagnostic utility of a new diagnostic criteria for amyotrophic lateral sclerosis(ALS),abbreviated as the‘Gold Coast Criteria’,with the revised El Escorial(rEEC)and Awaji ***:Clinical and electrophysiological data of 1185 patients from January 2014 to December 2019 in the Peking Union Medical College Hospital ALS database were *** sensitivity of the Gold Coast criteria was compared to that of the possible rEEC and Awaji criteria(defined by the proportion of patients categorized as definite,probable,or possible ALS).Results:A final diagnosis of ALS was recorded in 1162 *** sensitivity of the Gold Coast criteria(96.6%,95%confidence interval[CI]=95.3%-97.5%)was greater than that of the rEEC(85.1%,95%CI=82.9%-87.1%)and Awaji(85.3%,95%CI=83.2%-87.3%).In addition,the sensitivity of the novel criteria maintained robust across subgroups,and the advantage was more prominent in limb-onset ALS patients and those who completed electromyographic *** those who did not achieve any of the rEEC diagnostic categories,the sensitivity of Gold Coast criteria was 84.4%.Conclusions:The current study demonstrated that the Gold Coast criteria exhibited greater diagnostic sensitivity than the rEEC and Awaji criteria in a Chinese ALS *** application of the Gold Coast criteria should be considered in clinical practice and future therapeutic trials.

关键词： Amyotrophic lateral sclerosis diagnostic criteria Gold Coast Sensitivity

A 3-D Multiuser HAP-MIMO Channel Model Based on Dynamic Evolution of LOS Components

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 2019年第3期28卷 645-650页

作者： LIAN Zhuxian JIANG Lingge he Chen he di Department of Electronic Engineering Shanghai Jiaotong University National Mobile Communications Research Laboratory Southeast University

A theoretical Three dimensional(3-D) multiuser High altitude platform(HAP) Multipleinput multiple-output(MIMO) channel model based on dynamic evolution of the Line-of-sight(LOS) components is proposed. In this paper, we consider that the LOS components could re-appear after they have vanished,and a two-state Continuous-time Markov chain(CTMC)is used to model the dynamic evolution of the LOS components. The survival probabilities of the LOS components are derived by using Chapman-Kolmogorov(C-K) equations, and the closed-form expressions are derived in this paper. Using the survival probabilities, the spatial correlation functions are derived. Measurements show that a two-state CTMC is indispensable to investigate the dynamic properties of the LOS components.

关键词： High altitude platform(HAP) Twostate Continuous-time Markov chain(CTMC) ChapmanKolmogorov(C-K) equations

Cooperative spectrum sensing based on stochastic resonance in 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

Science China(Information Sciences) 2014年第2期57卷 58-67页

作者： LIN YingPei he Chen JIANG LingGe he di Department of Electronic Engineering Shanghai Jiao Tong University

A new censoring cooperative spectrum sensing scheme based on stochastic resonance(SR)technique in cognitive radio(CR)network is proposed in this *** observations of the cooperative secondary users(SUs)whose statistics fall into the censoring interval are processed by SR system in the proposed *** hard fusion and the soft fusion for the censoring cooperative spectrum sensing scheme are analyzed *** analyses and simulation results show that the proposed censoring cooperative spectrum sensing scheme has the same detection performance as and lower computational complexity than the method that each cooperative SU performs spectrum sensing using SR-based energy detection,and its detection performance is superior to that of the conventional method that all the cooperative SUs perform spectrum sensing using energy detection in hard *** soft fusion,the proposed censoring cooperative spectrum sensing based on equal gain combination can achieve the optimal sensing performance approximately.

关键词： cognitive radio cooperative spectrum sensing stochastic resonance information fusion

The Invariance Principle for p-■Chain

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2007年第1期23卷 41-56页

作者： di he HU Zheng Yan XIAO School of Mathematics and Statistics Wuhan University Wuhan 430072 P. R. China School of Statistics Renmin University of China Beijing 100872 P. R. China

There are two parts in this paper. In the first part we construct the Markov chain in random environment（MCRE）, the skew product Markov chain and p-θ^→ chain from a random transition matrix and a two-dimensional probability distribution, and in the second part we prove that the invarianee principle for p-θ^→ chain, a more complex non-homogeneous Markov chain, is true under some reasonable conditions. This result is more powerful.

关键词： random transition matrix Markov chain in random environment skew product Markov chain p-θ^→ chain invariance principle

BDS B1I multipath channel statistical model comparison between static and dynamic scenarios in dense urban canyon environment

在线全文

学校读者我要写书评

暂无评论

Satellite Navigation 2020年第1期1卷 287-302页

作者： Xin Chen di he Ling Pei Shanghai Key Laboratory of Navigation and Location-based Service School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityDongchuan Road 800Shanghai 200240China

Global Navigation Satellite System(GNSS)multipath channel models are fundamental and critical for signal simulation and receiver performance *** also aid the designing of suitable multipath error mitigation algorithms when the properties of multipath channel are ***,there is insufficient existing research on BeiDou Navigation Satellite System(BDS)signal multipath channel *** this study,multipath channel statistical models are established on the basis of extensive datasets of the BDS B1I signal.A multipath parameter estimation algorithm is designed to extract information of multipath rays from the intermediate frequency *** delay,power loss,Doppler fading frequency,and lifetime distribution models for static and dynamic vehicle platforms are established and compared,and the effects of the satellite orbit type and platform speed on the models are *** results reveal the detailed distribution and variation characteristics of the multipath parameters and are valuable for the development of accurate urban navigation systems.

关键词： Multipath channel statistical model Multipath delay Multipath power loss Multipath Doppler fading frequency Multipath lifetime

Frequency hopping in IEEE 802.15.4 to mitigate IEEE 802.11 interference and fading

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 Engineering and Electronics 2018年第3期29卷 445-455页

作者： JAVED Umer he di LIU Peilin YANG Yueming Shanghai Key Laboratory of Navigation and Location-based Services Shanghai Jiao Tong University Shanghai Panchip Microelectronics Co. Ltd

In this paper, we investigate the issues of initialization and deployment of wireless sensor networks（WSNs） under IEEE 802.11 b/g interference and fading channels using frequency hopping（FH）. We propose an FH algorithm for WSNs, which is implemented and tested with a pair of nodes employing IPv6 over low power wireless personal area networks（6 LoWPAN） *** merits and demerits of the proposed FH scheme in WSNs are studied under strong IEEE 802.11 b/g interference and frequency selective fading channels. We compare the performance results of the proposed FH scheme with those obtained by single-channel radio in WSNs, and show that FH maintains very reliable data rates in the presence of adverse conditions where the single-channel radio fails. We determine a minimum center frequency offset of channels between IEEE 802.15.4 and IEEE 802.11 b/g-based networks, which guarantees the error free network operation of IEEE802.15.4 using a single channel. We design a second FH procedure comprising only four free channels（15, 20, 25, and 26） of IEEE 802.15.4 standard, and show that in the presence of nearby IEEE 802.11 b/g interference, the IEEE 802.15.4 data rate using this method is always 98% and more.

关键词： IEEE 802.15.4 wireless sensor networks(WSNs) frequency hopping(FH) interference avoidance coexistence

Harmonic Moments of Branching Processes in Random Environments

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2009年第7期25卷 1087-1096页

作者： Wei Gang WANG Ping LV di he HU School of Statistics and Mathematics Zhejiang Gongshang University Hangzhou 310018 P. R. China Department of Science Hangzhou Normal University Hangzhou 310036 P. R. China School of Mathematics and Statistics Wuhan University Wuhan 430072 P. R. China

We consider harmonic moments of branching processes in general random environments. For a sequence of square integrable random variables, we give some conditions such that there is a positive constant c that every var... 详细信息

关键词： branching processes in random environments harmonic moments

Application of permanganate in the oxidation of micropollutants:a mini review

在线全文

学校读者我要写书评

暂无评论

Frontiers of Environmental Science & Engineering 2010年第4期4卷 405-413页

作者： Xiaohong GUAN di he Jun MA Guanghao CheN State Key Lab of Urban Water Resource and Environment(HIT) Harbin Institute of TechnologyHarbin 150001China Department of Civil and Environmental Engineering Hong Kong University of Science and TechnologyKowloonHong KongChina

As a green oxidant,permanganate has received considerable attention for the removal of micropollutants in drinking water *** provide a better understanding of the oxidation of organic micropollutants with permanganate,the oxidation kinetics of 32 micropollutants were *** pollutants include algal toxins,endocrine disrupting chemicals(EDCs),and *** oxidation kinetics of micropollutants by permanganate were found to be first order with respect to both contaminant and permanganate concentrations from which second-order rate constants(k″)were *** oxidized the heterocyclic aromatics with vinyl moiety(i.e.,microcystins,carbamazepine,and dichlorvos)by the addition of double *** the polycyclic aromatic hydrocarbons(PAHs)with alkyl groups,permanganate attacked the benzylic C-H through abstraction of *** mechanism for the oxidation of phenolic EDCs by permanganate was a single electron transfer and aromatic ring *** presence of background matrices could enhance the oxidation of some phenolic EDCs by permanganate,including phenol,chlorinated phenols,bisphenol A,and *** toxicity of dichlorvos solution increased after permanganate oxidation,and the estrogenic activity of bisphnol A/estrone increased significantly at the beginning of permanganate ***,the toxicity of degradation products or intermediates should be determined in the permanganate oxidation processes to better evaluate the applicability of *** influence of background ions on the permanganate oxidation process is far from clear and should be elucidated in the future studies to better predict the performance of permanganate oxidation of ***,methods should be employed to catalyze the permanganate oxidation process to achieve better removal of micropollutants.

关键词： pharmaceuticals endocrine disrupting chemicals(EDCs) algal toxins permanganate oxidation

Cosmic Neutrino Time Delay Relative to Photons

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 Physics Letters 2004年第7期21卷 1236-1239页

作者： LUOXin-Lian PENGQiu-he ZHANGLing-di BAIHua CHOUChih-Kang DepartmentofAstronomy NanjingUniversityNanjing210093

By solving the Friedmann–Robertson–Walker (FRW) geodesic equations for a free test particle with finite mass, we extend the widely used time-of-flight delay expression, which is just valid locally in the neighbourhood of our Galaxy, to the cosmic distance scale. If neutrino masses are known, this may provide a potential method to determine a large scale geometry of the Universe.

关键词： Timing circuits

Task Coordination Organization Model and the Task Allocation Algorithm for Resource Contention of the Syncretic System

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Tsinghua Science and Technology 2016年第4期21卷 459-470页

作者： Danfeng Wu Guangping Zeng di he Zhaopeng Qian Qingchuan Zhang School of Computer&Communication Engineering University of Science&Technology BeijingBeijing 100083China School of Software Liaoning Technical UniversityHuludao 125105China Beijing Key Laboratory of Knowledge Engineering for Materials Science Beijing 100083China Graduate Center City University of New YorkNew YorkNY 10016USA

At present, robot embedded systems have some common problems such as closure and poor dynamic evolution. Aiming at resolving this situation, our paper focuses on improvements to the robot embedded system and sets up a new robot system architecture, and we propose a syncretic mechanism of a robot and SoftMan （SM）. In the syncretic system, the structural organization of the SoftMan group and its modes are particularly important in establishing the task coordination mechanism. This paper, therefore, proposes a coordination organization model based on the SoftMan group, and studies in detail the process of task allocation for resource contention, which facilitates a rational allocation of system resources. During our research, we introduced Resource Requirement Length Algorithm （RRLA） to calculate the resource requirements of the task and a resource conformity degree allocation algorithm of Resource Conformity Degree Algorithm （RCDA） for resource contention. Finally, a comparative evaluation of RCDA with five other frequently used task allocation algorithms shows that RCDA has higher success and accuracy rates with good stability and reliability.

关键词： SoftMan robot syncretic system organization model task allocation game theory