oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2019 ( 197 )

2018 ( 2223 )

2017 ( 2109 )

2016 ( 2090 )

Custom range...

Search Results: 1 - 10 of 126949 matches for " YingKe Li "
All listed articles are free for downloading (OA Articles)
Page 1 /126949
Display every page Item
Regulation of innate receptor pathways by microRNAs
Yue Zhang,YingKe Li
Science China Life Sciences , 2013, DOI: 10.1007/s11427-012-4428-2
Abstract: The innate immune response provides the initial defense against infection. This is accomplished by families of pattern recognition receptors (PRRs) that bind to conserved molecules in bacteria, fungi and viruses. PRRs are finely regulated by elaborate mechanisms to ensure a beneficial outcome in response to foreign invaders. MicroRNAs (miRNAs) are a class of small non-coding regulatory RNAs that are emerging as important regulators in immune responses at the post-transcriptional level, through the inhibition of translation, or by inducing mRNA degradation. It has been shown that miRNAs have unique expression profiles in cells of the innate immune systems and play pivotal roles in regulating the signal pathways of innate receptors, including Toll-like receptors, RIG-I-like receptors and Nod-like receptors. We have summarized the recent literature providing new insights into the regulation of innate receptor pathways by miRNAs.
Permanence for a Delayed Nonautonomous SIR Epidemic Model with Density-Dependent Birth Rate
Li Yingke,Chen Liang,Wang Kai
Discrete Dynamics in Nature and Society , 2011, DOI: 10.1155/2011/350892
Abstract: Based on some well-known SIR models, a revised nonautonomous SIR epidemic model with distributed delay and density-dependent birth rate was considered. Applying some classical analysis techniques for ordinary differential equations and the method proposed by Wang (2002), the threshold value for the permanence and extinction of the model was obtained. 1. Introduction For understanding the spread of infectious diseases in population, mathematical models that use the theories of ordinary differential equations in epidemiology have been developed rapidly. Epidemic models with delay, including either the autonomous continuous systems or the discrete ones, were discussed by many authors [1–13]. The important subjects for this models are looking for the threshold value that determines whether the infectious disease will be permanent or extinct. Hence, permanence of disease plays an important role in epidemiology. Furthermore, it is well known that models with distributed delay are more appropriate than the discrete ones because it is considered more realistic to assume the infectivity to be a function of the duration since infection and up to some maximum duration. Recently, Song and Ma in [4] and Song et al. in [5] discussed the permanence of disease in a generalized autonomous SIR epidemic model with density dependent birth rate. On the other hand, for the nonautonomous systems [1] (and the reference therein), the literature is still very inadequate. Motivated by the works in [1, 2, 4, 5, 9, 10], in this paper, we will consider the following nonautonomous delayed systems with density-dependent birth rate: where denote the total number of a population at time , is the susceptible population, is the infective population and is the removed population. It is assumed that all newborns are susceptible. Functions and are instantaneous per capita mortality rates of susceptible, infective, and recovered population, respectively; functions and represent the birth rate of the population and the recovery rate of infectives, respectively; function reflects the relation between the birth rate and the density of population. The nonnegative constant is the time delay. The function is nondecreasing and has hounded variation such that 2. Preliminaries Firstly, we give some notations for convenience: if is a continuous bounded function defined on , then we set Secondly, for system (1.1), we introduce the following assumption: functions are nonnegative continuous bounded functions and have positive lower bounds. It is biologically natural to assume that (i.e., epidemics will
Preparation of nanocrystalline Co3O4 and its properties as supercapacitors
Lin Cao,Yingke Zhou,Mei Lu,Hulin Li
Chinese Science Bulletin , 2003, DOI: 10.1007/BF03183939
Abstract: Nanocrystallines Co3O4 with the particle diameter of 3 nm are prepared and tested as active electrode material for an electrochemical supercapacitor. The results of characterization indicate that the grain size of this material is very small; the specific surface area is very high (192 m2/g); the distributions of pore diameter are desirable and effective; furthermore, the agglomeration problem among small particles was solved to a certain extent. The electrochemical tests show that the electrode prepared with the Co3O4 exhibits distinct characteristic of capacitance and very high specific capacitance of 365–401 F/g. Additionally, the main attribute of capacitance, namely supercapacitance, was also testified.
Preparation of nanocrystalline Co3O4 and its properties as supercapacitors
Preparation of nanocrystalline Co_3O_4 and its properties as supercapacitors

CAO Lin,ZHOU YingKe,LU Mei,LI Hulin,
CAO Lin
,ZHOU Yingke,LU Mei & LI Hulin

科学通报(英文版) , 2003,
Abstract: Nanocrystallines Co3O4 with the particle diameter of 3 nm are prepared and tested as active electrode material for an electrochemical supercapacitor. The results of characterization indicate that the grain size of this material is very small; the specific surface area is very high (192 m2/g); the distributions of pore diameter are desirable and effective; furthermore, the agglomeration problem among small particles was solved to a certain extent. The electrochemical tests show that the electrode prepared with the Co3O4 exhibits distinct characteristic of capacitance and very high specific capacitance of 365-401 F/g. Additionally, the main attribute of capacitance, namely supercapacitance, was also testified.
Individual Planning in Agent Populations: Exploiting Anonymity and Frame-Action Hypergraphs
Ekhlas Sonu,Yingke Chen,Prashant Doshi
Computer Science , 2015,
Abstract: Interactive partially observable Markov decision processes (I-POMDP) provide a formal framework for planning for a self-interested agent in multiagent settings. An agent operating in a multiagent environment must deliberate about the actions that other agents may take and the effect these actions have on the environment and the rewards it receives. Traditional I-POMDPs model this dependence on the actions of other agents using joint action and model spaces. Therefore, the solution complexity grows exponentially with the number of agents thereby complicating scalability. In this paper, we model and extend anonymity and context-specific independence -- problem structures often present in agent populations -- for computational gain. We empirically demonstrate the efficiency from exploiting these problem structures by solving a new multiagent problem involving more than 1,000 agents.
Learning Markov Decision Processes for Model Checking
Hua Mao,Yingke Chen,Manfred Jaeger,Thomas D. Nielsen
Electronic Proceedings in Theoretical Computer Science , 2012, DOI: 10.4204/eptcs.103.6
Abstract: Constructing an accurate system model for formal model verification can be both resource demanding and time-consuming. To alleviate this shortcoming, algorithms have been proposed for automatically learning system models based on observed system behaviors. In this paper we extend the algorithm on learning probabilistic automata to reactive systems, where the observed system behavior is in the form of alternating sequences of inputs and outputs. We propose an algorithm for automatically learning a deterministic labeled Markov decision process model from the observed behavior of a reactive system. The proposed learning algorithm is adapted from algorithms for learning deterministic probabilistic finite automata, and extended to include both probabilistic and nondeterministic transitions. The algorithm is empirically analyzed and evaluated by learning system models of slot machines. The evaluation is performed by analyzing the probabilistic linear temporal logic properties of the system as well as by analyzing the schedulers, in particular the optimal schedulers, induced by the learned models.
Team Behavior in Interactive Dynamic Influence Diagrams with Applications to Ad Hoc Teams
Muthukumaran Chandrasekaran,Prashant Doshi,Yifeng Zeng,Yingke Chen
Computer Science , 2014,
Abstract: Planning for ad hoc teamwork is challenging because it involves agents collaborating without any prior coordination or communication. The focus is on principled methods for a single agent to cooperate with others. This motivates investigating the ad hoc teamwork problem in the context of individual decision making frameworks. However, individual decision making in multiagent settings faces the task of having to reason about other agents' actions, which in turn involves reasoning about others. An established approximation that operationalizes this approach is to bound the infinite nesting from below by introducing level 0 models. We show that a consequence of the finitely-nested modeling is that we may not obtain optimal team solutions in cooperative settings. We address this limitation by including models at level 0 whose solutions involve learning. We demonstrate that the learning integrated into planning in the context of interactive dynamic influence diagrams facilitates optimal team behavior, and is applicable to ad hoc teamwork.
Adaptive multipath mitigation algorithm for GPS C/A code track-ing loop
GPS码跟踪环自适应多径消除算法

QIN Xinxian,HAN Chengde,XIE Yingke,
覃新贤
,韩承德,谢应科

遥感学报 , 2010,
Abstract: Multipath not only degrades the sensitivity of a GPS receiver,but also becomes the dominant error resource in GPSpositioning systems. Multipath mitigation algorithm is the most significant in high sensitive and high accuracy GPS receivers. In this paper,multipath signal model in code tracking loop is studied first and a novel method for mitigation of multipath is presented which employs adaptive filtering recursive least square (RLS) algorithm. The system parameters need not be estimated in adaptive filtering algorithm and multipath signal can be filtered out directly. Under noisy scenario,the RLS algorithm is the best estimate for the filter weights with minimum least-squares errors. Simulation results show that the proposed method can reduce multipath error envelope effectively. The crossing-zero bias of the discriminator can be corrected which enhances the accuracy of code tracking in GPS receiver's delay-locked loop (DLL). The most importance is that the RLS algorithm is recursive and convenient to implement both in hardware and software.
Investigation of Surface Damage in Forming of High Strength and Galvanized Steel Sheets

Zhongqi Yu,Yingke Hou,Haomin Jiang,Xinping Chen,Weigang Zhang,

材料科学技术学报 , 2009,
Abstract: Powdering/exfoliating of coatings and scratching are the main forms of surface damage in the forming of galvanized steels and high strength steels (HSS), which result in increased die maintenance cost and scrap rate.In this study, a special rectangular box was developed to investigate the behavior and characteristics of surface damage in sheet metal forming (SMF) processes.U-channel forming tests were conducted to study the effect of tool hardness on surface damage in the forming of high strength steels and galvanized steels (hot-dip galvanized and galvannealed steels).Experimental results indicate that sheet deformation mode influences the severity of surface damage in SMF and surface damage occurs easily at the regions where sheet specimen deforms under the action of compressive stress.Die corner is the position where surface damage initiates.For HSS sheet, surface damage is of major interest due to high forming pressure.The HSS and hot-dip galvanized steels show improved ability of damage-resistance with increased hardness of the forming tool.However, for galvannealed steel it is not the forming tool with the highest hardness value that performs best.
基于WLD-LPQ特征的心盘螺栓故障图像检测算法
Research on fault recognition algorithm of center plate bolts based on WLD-LPQ features

张金敏,冯映科,王思明
ZHANG Jinmin
, FENG Yingke, WANG Siming

- , 2018,
Abstract: 针对货车心盘螺栓故障图像,提出一种基于韦伯局部描述符(Weber Local Descriptor , WLD)特征和局部相位量化(Local Phase Quantization, LPQ)特征融合的故障图像检测算法。该算法分为螺栓定位与识别2个步骤,采用间接定位法逐步定位感兴趣区域(Region of Interest, ROI),通过最大类间方差法(Otsu)和改进的Canny算法与图像投影结合定位螺栓部位;利用WLD特征和LPQ特征分别提取螺栓纹理,对其归一化,使用PCA降维特征向量,串行联合为WLD-LPQ特征,通过支持向量机SVM自动检测识别。研究结果表明:本文算法能快速准确定位,空间域与频率域结合的WLD-LPQ特征提高了检测识别率,平均检测识别率达到98%以上。
A method based on the combination of WLD and LPQ features was proposed which aimed fault image of center plate bolts of freight train. The algorithm was divided into two steps: bolt positioning and recognition. Firstly, the positioning of the ROI was investigated by the indirect location method. The Otsu Method and the improved Canny algorithm combined with image projection were used to position the bolt. Secondly, the WLD feature and LPQ feature were chosen to extract the bolt texture separately which were normalized next. Then this paper used the PCA dimensionality vector. Finally, the WLD feature and LPQ feature was proposed to form the WLD-LPQ feature which was combined with SVM for automatic recognition and detection. Test results show that this method can quickly locate the center plate bolts. The recognition rate is high and the average fault recognition rate is over 98%
Page 1 /126949
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.