作者机构：
[Yan, Guozheng] Cent China Normal Univ, Fac Math & Stat, Wuhan 430079, Peoples R China.;[Yao, Mao] Wuhan Univ Sci & Engn, Fac Sci, Wuhan 430074, Peoples R China.
通讯机构：
[Yan, Guozheng] C;Cent China Normal Univ, Fac Math & Stat, Wuhan 430079, Peoples R China.
关键词：
Linear sampling method;Boundary integral equation;Inverse scattering problem
摘要：
We consider the inverse scattering problem of determining the shape of a partially coated obstacle D. To this end, we solve a scattering problem for the Helmholtz equation where the scattered field satisfies mixed Dirichlet-Neumann-impedance boundary conditions on the Lipschitz boundary of the scatterer D. Based on the analysis of the boundary integral system to the direct scattering problem, we propose how to reconstruct the shape of the obstacle D by using the linear sampling method. (C) 2011 Published by Elsevier Ltd
期刊：
Journal of Statistical Planning and Inference,2011年141(5):1774-1782 ISSN：0378-3758
通讯作者：
Zhang, Runchu
作者机构：
[Hu, Jianwei] Cent China Normal Univ, Sch Math & Stat, Wuhan 430079, Peoples R China.;[Zhang, Runchu] NE Normal Univ, KLAS, Changchun 130024, Peoples R China.;[Zhang, Runchu] NE Normal Univ, Sch Math & Stat, Changchun 130024, Peoples R China.;[Zhang, Runchu; Hu, Jianwei] Nankai Univ, Sch Math Sci, Tianjin 300071, Peoples R China.;[Zhang, Runchu; Hu, Jianwei] Nankai Univ, LPMC, Tianjin 300071, Peoples R China.
通讯机构：
[Zhang, Runchu] N;NE Normal Univ, KLAS, Changchun 130024, Peoples R China.
摘要：
Zhang et al. (2008) introduced an aliased effect-number pattern (AENP) for two-level regular designs and proposed a general minimum lower-order confounding (GMC) criterion for choosing optimal designs. By using a finite projective geometric formulation, Zhang and Mukerjee (2009a) characterized GMC designs via complementary designs for general s-level case, and to find GMC designs, for some special cases they proved a result that a design T can have GMC only if T¯ is contained in a specific flat. In this paper, we first generalize the result to general cases for s=2. Then, we prove that, for any given n and m, a GMC design minimizes A3, the first term of the wordlengh pattern of regular 2n−m designs. Furthermore, we find out the unique optimal confounding structure between main effects and two-factor interactions, and prove that minimizing A3 is a sufficient and necessary condition for a regular design to have the structure.
摘要：
In this paper we are interested in some chemotaxis system with two species:{(e)u/(e)t=DuΔu-Du▽(ux(w)▽w)+u(1-u-a1v) (e)u/(e)t=DvΔv+ρv(1-a2u-v) (e)w/(e)t=h(u,w) Asa1≥0,a2≥0,x(w)=1/w,h(u,w)=u-δw,and(p)＞0,weprove that the system has a global solution.
摘要：
In this paper, we study the asymptotic behavior of solutions to one-dimensional compressible Navier-Stokes equations with gravity and vacuum for is entropic flows with density-dependent viscosity mu(rho)=c rho(theta). Under some suitable assumptions on the initial date and gamma > 1, if theta is an element of 2 (0, gamma/2], we prove the weak solution (rho(x, t), u(x, t)) behavior asymptotically to the stationary one by adapting and modifying the technique of weighted estimates. This result improves the one in [5] where Duan showed that the weak solution converges to the stationary one in the sense of integral for shallow water model. In addition, if theta is an element of (0, (gamma)(2)] boolean AND (0, gamma - 1], following the same idea in [9], we estimate the stabilization rate of the solution as time tends to infinity in the sense of L-infinity norm, weighted L-2 norm and weighted H-1 norm.
作者机构：
Schoo of Mheics nd Sisics, Cenr Chin Nor Universiy, Wuhn 430079, P .R .ChinSchoo of Mheics nd Sisics, Cenr Chin Nor Universiy, Wuhn 430079, P .R .Chin
会议名称：
International congress on mathematical biology
会议时间：
2011-06-03
会议地点：
Nanjing(CN)
会议论文集名称：
Proceedings of the 5th international congress on mathematical biology. vol. 1
关键词：
GLV Equations;Limit cycle;Nonlinear disturbance;Tangent vector field
摘要：
In this article, we discussed the nonlinear disturbance system of the cyclic predator system at same inconstant growth rate. By setting up the bridge between the vector field xf(x)+Q(x)and the tangent vector field Qr(u) on two-dimensional manifold sphere S2 and using the theory of quasi-homogeneous vector field, we got the conditions of the existence of the closed orbit to the system.
作者机构：
School of Mathematics and Quantitative Economics,Hubei University of Education,Wuhan 430205,China;School of Mathematics and Statistics, Central China Normal University,Wuhan 430079, China
会议名称：
The 5th International Congress on Mathematical Biology(第五届国际生物数学大会 ICMB 2011)
会议时间：
2011-06-01
会议地点：
南京
会议论文集名称：
The 5th International Congress on Mathematical Biology(第五届国际生物数学大会 ICMB 2011)论文集
关键词：
Limit cycle;global property;functional response model
摘要：
In this paper, we have studied the global properties of a class of predator-prey model with Holling type III functional response. We have obtained the necessary and sufficient conditions of the global stability of the positive equilibrium and the existence of the unique limit cycle of the model.
摘要：
In this paper, the compressible non-isentropic Navier–Stokes–Poisson (NSP) system is considered in R3 and the influences of internal electric field on the qualitative behaviors of solutions are analyzed. We observe that the electric field leads to the rotating phenomena in charge transport and reduces the speed of fluid motion, but it does not influence the transport of charge density and the heat diffusion. Indeed, we show that both density and temperature of the NSP system converge to their equilibrium state at the same rate (1+t)−34 as the non-isentropic compressible Navier–Stokes system, but the momentum decays at the rate (1+t)−14, which is slower than the rate (1+t)−34 for the pure compressible Navier–Stokes system. These convergence rates are also shown to be optimal for the non-isentropic compressible NSP system.
期刊：
Advances in Mathematics,2011年226(4):3088-3104 ISSN：0001-8708
通讯作者：
Puig, Lluis
作者机构：
[Puig, Lluis] Inst Math Jussieu, CNRS, F-94340 Joinville Le Pont, France.;[Zhou, Yuanyang] Cent China Normal Univ, Dept Math & Stat, Wuhan 430079, Peoples R China.;[Puig, Lluis] Inst Math Jussieu, CNRS, 6 Av Bizet, F-94340 Joinville Le Pont, France.
通讯机构：
[Puig, Lluis] I;Inst Math Jussieu, CNRS, 6 Av Bizet, F-94340 Joinville Le Pont, France.
摘要：
Coaxial magnetic gear (CMG) is a non-contact device for torque transmission and speed variation which exhibits promising potential in several industrial applications, such as electric vehicles, wind power generation and vessel propulsion. CMG works lying on the modulating-effect aroused by the ferromagnetic segments. This paper investigates the optimum design for improving the modulating-effect. Firstly, the operating principle and the modulating-effect is analyzed by using 1-D field model, which demonstrates that the modulating- effect is essential for the torque transmission capacity of CMGs, and the shape of the ferromagnetic segments have impact on the modulating- effect. Secondly, the fitted model of the relationship between the maximum pull-out torque and the shape factors including radial height, outer-edge width-angle and inner-edge width-angle is built up by using surface response methodology. Moreover, FEM is engaged to evaluate its accuracy. Thirdly, the optimum shape of the ferromagnetic segment is obtained by using genetical algorithm.
摘要：
Let G be a graph and let Q(G) be its signless Laplacian matrix. When G is a unicyclic (respectively, bipartite) graph we obtain sharp upper and lower bounds for the permanent of Q(G) in terms of the order of G. Improved bounds are obtained in terms of the given girth of G. In each of these cases, we characterize the extremal graphs.
作者机构：
[Li, Shuchao; Zhao, Qin] Cent China Normal Univ, Fac Math & Stat, Wuhan 430079, Peoples R China.
通讯机构：
[Li, Shuchao] C;Cent China Normal Univ, Fac Math & Stat, Wuhan 430079, Peoples R China.
关键词：
Zagreb indices;Tree;Unicyclic graph;Perfect matching;m-matching
摘要：
For a molecular graph, the first Zagreb index M-1 is equal to the sum of squares of the vertex degrees, and the second Zagreb index M-2 is equal to the sum of products of degrees of pairs of adjacent vertices. In this paper, we first obtain a sharp upper bound on M-1-values of trees in terms of the order and the given size of matching. Then we investigate Zagreb indices of unicyclic conjugated graphs G (i.e., unicyclic graphs with a perfect matching) and a sharp upper bound on M-1(G), M-2(G) are determined, respectively. The sharp upper bounds for Zagreb indices of unicyclic graphs in terms of the order and given size of matching are also determined.
