本文利用具有重结点的自然样条函数,讨论了线性泛函Ff=sum from i=0 to n-1[integral from a to b a_i(x)D^i f(x)dx+sum from j=0 to L^1 b_(ij)D^i f(x_(ij))]的广义Sard逼近问题。文中给出了线性泛函Lf=sum from i=0 to k sum from j...本文利用具有重结点的自然样条函数,讨论了线性泛函Ff=sum from i=0 to n-1[integral from a to b a_i(x)D^i f(x)dx+sum from j=0 to L^1 b_(ij)D^i f(x_(ij))]的广义Sard逼近问题。文中给出了线性泛函Lf=sum from i=0 to k sum from j=0 to k_1-1 a_(ij)D^j f(x_i)逼近F为n-1阶准确的存在定理与唯一性定理;给出了L做为F的广义Sard逼近的充分必要条件。展开更多
将Rn的开子集上非线性映射的导算子,一致可微性等概念推广到定义在Rn的一般子集上的映射,然后建立相应的Sard定理,并将所得结果用于一类含参数的椭圆问题:∫Ωudx=α下解的通有有限性,-Δu+f(u)=(λ), u υ=0在约束条件:m(u):=1|Ω...将Rn的开子集上非线性映射的导算子,一致可微性等概念推广到定义在Rn的一般子集上的映射,然后建立相应的Sard定理,并将所得结果用于一类含参数的椭圆问题:∫Ωudx=α下解的通有有限性,-Δu+f(u)=(λ), u υ=0在约束条件:m(u):=1|Ω|其中f严格单调递增,∈C1([0,1];L2(Ω)).我们证明存在零测集E R1使得对所有α∈R1\E,该问题只有有限个解(u,λ).展开更多
Sufficient conditions were given to assert that between any two Banach spaces over K, Fredholm mappings share at least one .value in a specific open ball. The proof of the result is constructive and based upon continu...Sufficient conditions were given to assert that between any two Banach spaces over K, Fredholm mappings share at least one .value in a specific open ball. The proof of the result is constructive and based upon continuation methods.展开更多
Let J be the zero set of the gradient fx of a function f:Rn→R. Under fairly general conditions the stochastic approximation algorithm ensures d(f(xk),f(J))→0, as k→∞. First of all, the paper considers this proble...Let J be the zero set of the gradient fx of a function f:Rn→R. Under fairly general conditions the stochastic approximation algorithm ensures d(f(xk),f(J))→0, as k→∞. First of all, the paper considers this problem: Under what conditions the convergence d(f(xk),f(J)) → 0 implies k →∞ d(xk,J)→O. It is shown that such implication takes place if fx is continuous and f(J) is nowhere dense. Secondly, an intensified version of Sard's theorem has been proved, which itself is interesting. As a particular case, it provides two independent sufficient conditions as answers to the previous question: If f is a C1 function and either i) J is a compact set or ii) for any bounded set B, f-1(B)is bounded, then f(J) is nowhere dense. Finally, some tools in algebraic geometry are used to prove that j(J) is a finite set if f is a polynomial. Hence f(J) is nowhere dense in the polynomial case.展开更多
文摘本文利用具有重结点的自然样条函数,讨论了线性泛函Ff=sum from i=0 to n-1[integral from a to b a_i(x)D^i f(x)dx+sum from j=0 to L^1 b_(ij)D^i f(x_(ij))]的广义Sard逼近问题。文中给出了线性泛函Lf=sum from i=0 to k sum from j=0 to k_1-1 a_(ij)D^j f(x_i)逼近F为n-1阶准确的存在定理与唯一性定理;给出了L做为F的广义Sard逼近的充分必要条件。
文摘将Rn的开子集上非线性映射的导算子,一致可微性等概念推广到定义在Rn的一般子集上的映射,然后建立相应的Sard定理,并将所得结果用于一类含参数的椭圆问题:∫Ωudx=α下解的通有有限性,-Δu+f(u)=(λ), u υ=0在约束条件:m(u):=1|Ω|其中f严格单调递增,∈C1([0,1];L2(Ω)).我们证明存在零测集E R1使得对所有α∈R1\E,该问题只有有限个解(u,λ).
基金Project supported by D.G.E.S. Pb 96-1338-CO 2-01 and the Junta de Andalucia
文摘Sufficient conditions were given to assert that between any two Banach spaces over K, Fredholm mappings share at least one .value in a specific open ball. The proof of the result is constructive and based upon continuation methods.
基金Supported by the National Natural Science Foundation of China (G69774008, G59837270, G1998020308)and National Key Project.
文摘Let J be the zero set of the gradient fx of a function f:Rn→R. Under fairly general conditions the stochastic approximation algorithm ensures d(f(xk),f(J))→0, as k→∞. First of all, the paper considers this problem: Under what conditions the convergence d(f(xk),f(J)) → 0 implies k →∞ d(xk,J)→O. It is shown that such implication takes place if fx is continuous and f(J) is nowhere dense. Secondly, an intensified version of Sard's theorem has been proved, which itself is interesting. As a particular case, it provides two independent sufficient conditions as answers to the previous question: If f is a C1 function and either i) J is a compact set or ii) for any bounded set B, f-1(B)is bounded, then f(J) is nowhere dense. Finally, some tools in algebraic geometry are used to prove that j(J) is a finite set if f is a polynomial. Hence f(J) is nowhere dense in the polynomial case.