共查询到20条相似文献,搜索用时 171 毫秒
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本文引入了近切触流形(M,ø,ξ,η,g)中φ*-解析向量场的概念,并研究了其性质.利用近切触流形的性质,证明了切触度量流形中的φ*-解析向量场v是Killing向量场且φv不是φ*-解析的.特别地,如果近切触流形M是正规的,得到v与ξ平行且模长为常数.另外,证明了3维的切触度量流形不存在非零的φ*-解析向量场. 相似文献
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本文讨论了积流形的P-形式上Laplace算子谱的唯一性问题,在紧Kachler流形乘积和紧Sasaki流形乘积的两类积流形中,CPn×CPn和S2n+1(1)×S2n+1(1)是P-形式上Laplacce算子谱特征。 相似文献
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2—调和映照的复合映照 总被引:2,自引:0,他引:2
本文研究了Ricmann流形间2—调和映照的复合映照的性质及其应用.按照J.Eells和L.Lemaire在文献[1]中的设想,姜国英在[2]中通过计林某一泛函数的第一、二变分的方法,探讨了Riemann流形间的2—调的映照f:M→N,它的张力场τ(f)满足方程:(?)其中{ek}为M的局部标准正交林架场.A*A是向量丛f-1TN上的迹Laplace算子,RN是N的曲率算子.当M紧致时,2—调和映照f恰是使2—能量泛函(?)取临界值的映射.显然,它是调和映照的一种推广.本文研究了Ricmann流形间2—调和映照的复含映照的一个性质,并给出了它的应用. 相似文献
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设M是复n维Stein流形;并设开集D??M具有逐块C1边界.本文利用陈度量和陈联络,把Stein流形上(0,q)形式的Koppelman-Leray-Norguet公式推广到(p,q)形式,并得到D上?-方程的解.最后,还给出了Stein流形上实非退化强拟凸多面体的Koppelman-Leray-Norguet公式及其?-方程的解. 相似文献
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本文通过对C-R流形上的Pfaffian系的分析,证明了一般抽象定义的C-R流形上存在C-R叶及复叶,并给出了这些叶的性质,其中部分关于复叶的结果对Cn中C-R子流形由Freeman所得,而C-R叶的结果则是新的. 相似文献
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设N n+p是截面曲率KN 满足1/2 <δ≤ KN≤ 1 的n+p维局部对称完备的δ-Pinching黎曼流形. Mn是Nn+p 的紧致极小子流形. 该文讨论了这类子流形关于Ricci曲率有关的Pinching定理. 相似文献
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We describe the type of reasoning used in the typical fuzzy logic controller, the Mamdani reasoning method. We point out the basic assumptions in this model. We discuss the S-OWA operators which provide families of parameterized “andlike” and “orlike” operators. We generalize the Mamdani model by introducing these operators. We introduce a method, which we call Direct Fuzzy Reasoning (DFR), which results from one choice of the parameters. We develop some learning algorithms for the new method. We show how the Takagi-Sugeno-Kang (TSK) method of reasoning is an example of this DFR method. 相似文献
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We study the almost periodic solutions of Euler equations and of some more general Difference Equations. We consider two different notions of almost periodic sequences, and we establish some relations between them. We build suitable sequences spaces and we prove some properties of these spaces. We also prove properties of Nemytskii operators on these spaces. We build a variational approach to establish existence of almost periodic solutions as critical points, We obtain existence theorems fornonautonomous linear equations and for an Euler equation with a concave and coercive Lagrangian. We also use a Fixed Point approach to obtain existence results for quasi-linear Difference Equations. 相似文献
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Hande Yaman 《Mathematical Programming》2006,106(2):365-390
We consider the vehicle routing problem where one can choose among vehicles with different costs and capacities to serve the
trips. We develop six different formulations: the first four based on Miller-Tucker-Zemlin constraints and the last two based
on flows. We compare the linear programming bounds of these formulations. We derive valid inequalities and lift some of the
constraints to improve the lower bounds. We generalize and strengthen subtour elimination and generalized large multistar
inequalities. 相似文献
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Shuji Machihara 《Journal of Mathematical Analysis and Applications》2003,281(2):552-564
We study the inviscid limit of the complex Ginzburg-Landau equation. We observe that the solutions for the complex Ginzburg-Landau equation converge to the corresponding solutions for the nonlinear Schrödinger equation. We give its convergence rate. We estimate the integral forms of solutions for two equations. 相似文献
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We apply the theory of fuzzy subsets to the multiple objective decision problem of stock selection. We allow our objectives to have varying degrees of importance. We discuss various criteria used in selecting stocks. We indicate some procedures for subjectively evaluating the membership functions associated with these criteria. 相似文献
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ABSTRACTWe study the inverse problem of identifying a variable parameter in variational and quasi-variational inequalities. We consider a quasi-variational inequality involving a multi-valued monotone map and give a new existence result. We then formulate the inverse problem as an optimization problem and prove its solvability. We also conduct a thorough study of the inverse problem of parameter identification in noncoercive variational inequalities which appear commonly in applied models. We study the inverse problem by posing optimization problems using the output least-squares and the modified output least-squares. Using regularization, penalization, and smoothing, we obtain a single-valued parameter-to-selection map and study its differentiability. We consider optimization problems using the output least-squares and the modified output least-squares for the regularized, penalized and smoothened variational inequality. We give existence results, convergence analysis, and optimality conditions. We provide applications and numerical examples to justify the proposed framework. 相似文献
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研究项链李代数的性质,给出了其中心元的表示形式,证明了项链李代数非半单、非可解,通过构造项链李代数的可解非幂零子代数,证明了当箭图中有长度大于1的循环时,项链李代数非幂零.还给出了没有圈的箭图上项链李代数的分解. 相似文献
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Przemys?aw Górka 《Journal of Mathematical Analysis and Applications》2008,341(2):1413-1426
We examine the evolution of crystals in three dimensions. We assume that the Wulff shape is a prism with a hexagonal base. We include the Gibbs-Thomson law on the crystal surface and the so-called Stefan condition. We show local in time existence of solutions assuming that the initial crystal has admissible shape. 相似文献
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Periodic non-autonomous second-order dynamical systems 总被引:1,自引:0,他引:1
Martin Schechter 《Journal of Differential Equations》2006,223(2):290-302
We study the existence of periodic solutions for a second-order non-autonomous dynamical system. We give three sets of hypotheses which guarantee the existence of non-constant solutions. We were able to weaken the hypotheses considerably from those used previously for such systems. We employ a saddle point theorem using linking methods. 相似文献