检索结果-南通市图书馆

维普期刊数据库博看期刊

Maneuvering target tracking by adaptive statistics model

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2013年第1期20卷 108-114页

作者： JIN Xue-bo du jing-jing BAO Jia College of Computer and Information Engineering Beijing Technology and Business University College of Informatics Zhejiang Sci-Tech University

A good model can extract useful information about the target＇s state from observations effectively. There are many models used to tracking a, maneuvering target such as constant-velocity （CV） model, Singer acceleration model （zero-mean first-order Markov model） and current model （mean-adaptive acceleration model）, etc. While due to the complexity of maneuvering target, to seek the target model which can get better performance is still a subject worthy of study. Based on statistics relation between the autocormlation function and the covariance of Markov random processing, this paper develops a model which can adaptively adjust system parameters on line. Simulations show the good estimation performance get by the model developed here, and comparing CV, Singer and current models, the model can adaptively get the model parameter while tracking the trajectory and needn＇t doing several tests to obtain a priori parameter.

关键词： maneuvering target target model statistics relation state estimation

Neuroimaging studies on cognitive impairment due to cerebral small vessel disease

在线全文

学校读者我要写书评

暂无评论

Stroke & Vascular Neurology 2019年第2期4卷 99-101页

作者： jing du Qun Xu Neurology Shanghai Jiao Tong University School of Medicine Affiliated Renji HospitalShanghaiChina Health Manage Center Shanghai Jiao Tong University School of Medicine Affiliated Renji HospitalShanghaiChina

Vascular cognitive impairment (VCI) is a major contributor to age-related dementing illnesses which imposes a tremendous burden on families and society. It is a heterogeneous group of brain disorders. However, cerebral small vessel disease (CSVD) accounts for about 50%-70% of VCI, which represented a more homogeneous subtype of VCI. Advanced multimodal neuroimaging techniques like brain network connectome analyses are currently applied to explore the underlying mechanism of VCI. Some progress in the field of structural and functional brain network researches on a poststroke longitudinal CSVD cohort (Renji CSVD Cohort Study) was reported. Global and regional brain network characters were compared between patients with CSVD and healthy control. It suggested that distributed brain structural network disruption may play a pivot role in the cognitive decline. The results showed that brain structural network characters have distinctive differentiating capacity on the cognition of patients with CSVD.

关键词： cerebral impairment network

Lipopolysaccharide-induced Trigeminal Ganglion Nerve Fiber Damage is Associated with Autophagy Inhibition

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

Current Medical Science 2023年第3期43卷 489-495页

作者： Yong LI jing LI Sheng-sheng WEI jing du Refractive Surgery Center Shaanxi Eye HospitalXi'an People's Hospital(Xi'an Fourth Hospital)Affiliated Guangren HospitalSchool of MedicineXi'an Jiaotong UniversityXi'an 710004China

Objective This study aimed to determine whether lipopolysaccharide(LPS)induces the loss of corneal nerve fibers in cultured trigeminal ganglion(TG)cells,and the underlying mechanism of LPS-induced TG neurite *** TG neurons were isolated from C57BL/6 mice,and the cell viability and purity were maintained for up to 7 ***,they were treated with LPS(1µg/mL)or the autophagy regulator(autophibib and rapamycin)alone or in combination for 48 h,and the length of neurites in TG cells was examined by the immunofluorescence staining of the neuron-specific proteinβ***,the molecular mechanisms by which LPS induces TG neuron damage were *** The immunofluorescence staining revealed that the average length of neurites in TG cells significantly decreased after LPS ***,LPS induced the impairment of autophagic flux in TG cells,which was evidenced by the increase in the accumulation of LC3 and p62 *** pharmacological inhibition of autophagy by autophinib dramatically reduced the length of TG ***,the rapamycin-induced activation of autophagy significantly lessened the effect of LPS on the degeneration of TG *** LPS-induced autophagy inhibition contributes to the loss of TG neurites.

关键词： lipopolysaccharide autophagy trigeminal ganglion neurons

An Accurate and Extensible Machine Learning Classifier for Flow-Level Traffic Classification

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

China Communications 2018年第6期15卷 125-138页

作者： Gang Lu Ronghua Guo Ying Zhou jing du Chinese Luoyang electronic equipment center Luoyang 471003China

Machine Learning(ML) techniques have been widely applied in recent traffic ***, the problems of both discriminator bias and class imbalance decrease the accuracies of ML based traffic classifier. In this paper, we propose an accurate and extensible traffic classifier. Specifically, to address the discriminator bias issue, our classifier is built by making an optimal cascade of binary sub-classifiers, where each binary sub-classifier is trained independently with the discriminators used for identifying application specific traffic. Moreover, to balance a training dataset,we apply SMOTE algorithm in generating artificial training samples for minority *** evaluate our classifier on two datasets collected from different network border *** with the previous multi-class traffic classifiers built in one-time training process,our classifier achieves much higher F-Measure and AUC for each application.

关键词： traffic classification class imbalance dircriminator bias encrypted traffic machine learning

Comparison of Two Methods to Assess the Size Structure of Phytoplankton Community Assemblages, in Liaodong Bay, China

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2019年第5期18卷 1207-1215页

作者： SONG Lun WU jing du jing LI Nan WANG Kun WANG Peng State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHaerbin 150090China Key Laboratory of Marine Biological Resources and Ecology Liaoning Ocean and Fisheries Science Research Institute Dalian 116023China

Liaodong Bay is one of the largest semi-enclosed bays located in Bohai Sea,in northeast *** is an important feeding and spawning place,even wintering and breeding migration base for many marine *** size structure of phytoplankton communities is a key feature of marine ecosystems and can be used as an indicator for algae disaster,but the methods to evalute is still ***,we compared the size-fractionated chlorophyll-a method with a high-throughout sequencing method in an evaluation of the size structure of phytoplankton assemblages in Liaodong Bay,China,in *** proportion of picophytoplankton was estimated at just 19%according to the results based on size-fractionated chlorophyll-a,which likely represents a severe *** sequencing method confirmed that many kinds of phytoplankton species appeared in more than one size-fractionated filter membrane,with some even dominating where the filter membrane pore size was greater than the individual phytoplankton *** to the sequencing method,the phytoplankton assemblages in Liaodong Bay were dominated by picophytoplankton(average proportion=44%),followed by the nanophytoplankton(average 32%),a composition that is more consistent with other *** sequencing method provides a more robust way to assess the size structure and taxonomic diversity of marine phytoplankton communities.

关键词： size structure chlorophyll-a high-throughout sequencing Liaodong Bay

2D DEM simulation of particle mixing in rotating drum: A parametric study

在线全文

学校读者我要写书评

暂无评论

Particuology 2010年第2期8卷 141-149页

作者： Yong Xu Chunhui Xu Zhe Zhou jing du Daping Hu College of Sdence China Agricultural University Beijing 100083 China

Mixing behaviors of equal-sized glass beads in a rotating drum were investigated by both DEM simula- tions and experiments. The experiments indicated that higher rotation speed can significantly enhance mixing. The particle profiles predicted by 2D DEM simulation were compared with the experimental results from a quasi-2D drum, showing inconsistency due to reduction of contacts in the single-layer 2D simulation which makes the driving friction weaker than that in the quasi-2D test, better results could be reached by specifying a higher frictional coefficient between the particles and the cylinder wall. In order to explore the influences of physical properties （density, size or friction） on mixing behavior, numerical 2D simulations were carried out systematically, in which one examined specific property being examined was exaggerated while the others were kept the same as that in the control group. The DEM simulations reveal that particle density and size are the dominating factors affecting mixing behaviors, while the effect of frictional coefficient is less significant. However, segregation due to any of the factors can be diminished by specifying a proper particle size distribution （multi-size with lower size ratio）. 2009 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

关键词： Discrete Element Method Rotating drum Granule Mixing Mill Segregation

Artificial Intelligence and the Future of Education： Big Promises -Bigger Challenges

在线全文

学校读者我要写书评

暂无评论

学术界 2017年第4期 257-265页

作者： Jonathan Michael Spector du jing University of North Texas USA Beijing Normal University Beijing 100875

The history of educational technology in the last 50 years contains few instances of dramatic improvements in learning based on the adoption of a particular *** example involving artificial intelligence occurred in the 1990s with the development of intelligent tutoring systems( ITSs). What happened with ITSs was that their success was limited to well-defined and relatively simple declarative and procedural learning tasks(e. g.,learning how to write a recursive function in LISP; doing multi-column addition),and improvements that were observed tended to be more limited than promised(e. g.,one standard deviation improvement at best rather than the promised standard deviation improvement).Still,there was some progress in terms of how to conceptualize learning. A seldom documented limitation was the notion of only viewing learning from only content and cognitive perspectives( i. e.,in terms of memory limitations,prior knowledge,bug libraries,learning hierarchies and sequences etc.). Little attention was paid to education conceived more broadly than developing specific cognitive skills with highly constrained problems. New technologies offer the potential to create dynamic and multi-dimensional models of a particular learner,and to track large data sets of learning activities,resources,interventions,and outcomes over a great many learners. Using those data to personalize learning for a particular learner developing knowledge,competence and understanding in a specific domain of inquiry is finally a real possibility. While the potential to make significant progress is clearly possible,the reality is less not so promising. There are many as yet unmet challenging some of which will be mentioned in this paper. A persistent worry is that educational technologists and computer scientists will again promise too much,too soon at too little cost and with too little effort and attention to the realities in schools and universities.

关键词：智能教学系统认知技能教育技术人员中国

A Cauchy integral formula for(p,q)-monogenic functions withα-weight

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics(A Journal of Chinese Universities) 2024年第3期39卷 545-553页

作者： GAO Long du Xiao-jing LIU Yue XIE Yong-hong School of Mathematical Sciences Hebei Normal UniversityShijiazhuang 050024China

Firstly,some properties for(p,q)-monogenic functions withα-weight in Clifford analysis are ***,the Cauchy-Pompeiu formula is ***,the Cauchy integral formula and the Cauchy integral theorem for(p,q)-monogenic function... 详细信息

关键词： (p q)-monogenic functions with-weight Cauchy-Pompeiu formula Cauchy integral formula Cauchy integral theorem

Master event based backazimuth estimation and its application to downhole microseismic monitoring

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2022年第6期19卷 2675-2682页

作者： Xiao-Bo Meng Hai-Chao Chen Feng-Lin Niu Yi-jing du Department of Geophysics Chengdu University of TechnologyChengduSichuan610059China Unconventional Petroleum Research Institute and State Key Laboratory of Petroleum Resources and ProspectingChina University of PetroleumBeijing102249China Department of Earth Environmental and Planetary SciencesRice UniversityHoustonTX77005USA Petro China Research Institute of Petroleum Exploration and Development Beijing100083China

Microseismic monitoring provides a valuable tool for evaluating the effectiveness of hydraulic fracturing ***,robust detection and accurate location of microseismic events are challenging due to the low signal to noise ratio(SNR)of their signals on *** a downhole monitoring setting,P-wave polarization direction measured from 3-component records is usually considered as the backazimuth of the microseismic event,i.e.,the direction of the *** direction and arrival time difference between the P and S waves is used to locate the seismic *** SNR is low,an accurate estimate of event backazimuth becomes very challenging with the traditional covariance matrix *** we propose to employ a master event and use a grid search method to find the backazimuth of a target event that maximizes the dot product of the two backazimuthal vectors of the master and target *** compared the backazimuths measured with the proposed grid-search and the conventional covariance-matrix methods using a large synthetic *** found that the grid-search method yields more accurate backazimuth estimates from low SNR records when measurements are made at single geophone *** array data are combined,the proposed method also has some advantage over the covariance-matrix method,especially when the number of geophones is *** also applied the method to a microseismic dataset acquired by a hydraulic fracturing project at a shale play site in southwestern China and found that the relocated microseismic events tend to align along existing faults more tightly than those in the original catalog.

关键词： Hydraulic fracturing Microseismic event Back azimuth Master event Grid search Covariance-matrix