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Spreading and vanishing in a West Nile virus model with expanding fronts

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Science China Mathematics 2017年第5期60卷 841-860页

作者： TARBOUSH Abdelrazig K. LIN ZhiGui ZHANG MengYun School of Mathematical Science Yangzhou University Department of Mathematics Faculty of EducationUniversity of Khartoum

We study a simplified version of a West Nile virus （WNv） model discussed by Lewis et al. （2006）, which was considered as a first approximation for the spatial spread of WNv. The basic reproduction number R0 for the non-spatial epidemic model is defined and a threshold parameter RD for the corresponding problem with null Dirichlet boundary condition is introduced. We consider a free boundary problem with a coupled system, which describes the diffusion of birds by a PDE and the movement of mosquitoes by an ODE. The risk index R0^F（t） associated with the disease in spatial setting is represented. Sufficient conditions for the WNv to eradicate or to spread are given. The asymptotic behavior of the solution to the system when the spreading occurs is considered. It is shown that the initial number of infected populations, the diffusion rate of birds and the length of initial habitat exhibit important impacts on the vanishing or spreading of the virus. Numerical simulations are presented to illustrate the analytical results.

关键词： West Nile virus coupled system free boundary spreading and vanishing the risk index

GENERALIZED RECIPROCAL THEOREMS AND THEIR APPLICATIONS

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Applied Mathematics and Mechanics(English Edition) 2002年第2期23卷 203-210页

作者： FU Bao-lian(付宝连) Department of Civil Engineering and Mechanics Yanshan UniversityQinhuangdao066004 P R China

Generalized reciprocal theorems of non-coupled and coupled systems, which are valid for two deformed bodies with different constitutive relations are established by generalizing the idea of Betti's reciprocal theorem. When the constitutive relations of the two deformed bodies are all alike and linear elastic the generalized reciprocal theorem of non-coupled systems just becomes Betti's. Meanwhile the generalized reciprocal theorems are applied to simulate calculations in elasticity.

关键词： reciprocal theorem generalized reciprocal theorem non-coupled system coupled system

INVESTIGATION ON THE POWER FLOW OF FLOATING RAFT system BY A NEW APPROACH

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INVESTIGATION ON THE POWER FLOW OF FLOATING RAFT SYSTEM BY A...

Analytical research on structural-acoustic coupling of a cavity surrounded by flexible panel

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作者： Zhang Bing Song Kongjie and Sun Lingling School of Mechanical Engineering Shandong University Jinan China 250061

＜正＞ A new approach is developed to study thedynamic behavior of the floating raft coupled systemwhich comprises five substructures.A uniform form oftransfer matrix equations of different substructures isadopted here to represent their dynamic parameters,which makes it easy to deduce the transmitting powerflow of each interface between the *** the effectiveness of the new approach,thedynamics of a flexible raft isolation system is illustrated.

关键词： floating raft coupled system power flow

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Chinese Journal of Acoustics 2007年第2期26卷 138-157页

作者： JIN Guoyong YANG Tiejun LIU Zhigang JI Zhenlin LIWanyou School of Power and Energy Engineering Harbin Engineering University Harbin 150001

The structural-acoustic coupling characteristics, mechanisms, effect of structuralacoustic coupling on natural mode and natural frequencies of the system are analyzed the- oretically and numerically. Formulae for the natural frequencies of the coupled system are derived. Some new conclusions are obtained. Analytical results demonstrate that the strongly coupled system indicates obvious closed-loop feedback characteristics, whereas the weakly cou- pled system indicates obvious feedforward characteristics, and it is because of the presence of the feedback loop that the natural characteristics and natural frequencies are changed. Cluster coupling characteristic between the structural and acoustic modes for the regular cavity and panel system is found, which determines the coupling interaction between the flexible panel and cavity. Any mode in one mode cluster only interferes the modes and the modal natural frequencies in the same cluster independently. The modal cluster coupling changes not only the natural frequencies of the system but also the modal order and structural mode shape.

关键词： natural frequencies coupled system feedback loop mode shape

Extended Cognition as a Case of Bottomless Theory Building

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Journal of Philosophy Study 2013年第12期3卷 1071-1087页

作者： Gerhard Chr. Bukow University of Magdeburg

Extended cognition is the thesis that vehicles realizing cognitive systems can possibly extend beyond traditional boundaries of brain, skin, or skull. It is a popular thesis because of its counterintuitive consequence that coupled systems of vehicles of very different entities could form a realizer of one cognitive systems. Popular examples consist of human-handy-systems or human-notebook-systems, and it is a thesis that could non-dogmatically decide what individuates the realizers of cognitive systems. But the thesis is in need for individuation-criteria： How could we individuate a coupled system of different systems of vehicles？ We inspect some of the usually handled candidates for individuation-criteria and argue that in principal there will be no successful candidate due to methodological problems. We aim to show this by using a cookbook theory of extended cognition and add different types of candidates. No candidate is non-arbitrary or non-intrinsic, which leads the proponent to the forced selection between arbitrary or intrinsic candidates. We argue that without criteria, the talk about extended cognition is a bottomless pit that should only serve as an example for bottomless theory-building.

关键词： extended cognition cognitive system coupled system individuation-criteria

Conceptual model about the interaction between El Nio/ Southern Oscillation and Quasi-Biennial Oscillation in far west equatorial Pacific

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Science China Earth Sciences 2006年第8期49卷 889-896页

作者： LIU Qinyu1, LIU Zhengyu2,1 & PAN Aijun 1,3 1. Physical Oceanography Lab. & Atmosphere-Ocean Interaction and Climate Lab., Ocean University of China, Qingdao 266003, China 2. Center for Climate Research, University of Wisconsin-Madison, Madison, WI 53706-1695, USA 3. Environment and Dynamics Lab., Third Institute of Oceanography, Xiamen 361005, China

Interaction between the Quasi-Biennial Oscillation in far west equatorialPacific (QBOWP) and the El Nino/Southern Oscillation (ENSO) is studied using a new conceptual *** this conceptual model, the QBOWP effects on ENSO are achieved through two ways: (1) the oceanicKelvin wave along equatorial Pacific, and (2) the Atmospheric Walker Circulation anomaly, while ENSOeffects on QBOWP can be accomplished by the atmospheric Walker Circulation anomaly. Diagnosisanalysis of the model results shows that the Atmospheric bridge (Walker circulation) plays a moreimportant role in interaction between the ENSO and QBOWP than the oceanic bridge (oceanic Kelvinwave along equatorial Pacific); It is found that by the interaction of the ENSO and QBOWP, a freeENSO oscillation with 3-5 years period could be substituted by a oscillation with the quasi-biennialperiod, and the dominant period of SST anomaly and wind anomaly in the far west equatorial Pacifictends to be prolonged with enhanced ENSO forcing. Generally, the multi-period variability in thecoupled Atmosphere-Ocean system in the Tropical Pacific can be achieved through the interactionbetween ENSO and QBOWP.

关键词： El nino/southern oscillation quasi-biennial oscillation interaction coupled system kelvin wave walker circulation

Stabilization for a class of delayed coupled PDE-ODE systems with boundary control

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Stabilization for a class of delayed coupled PDE-ODE systems...