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1.
In this paper we have proved the theorem: Let p>1, and E be a real normed linear space, if the Lp-orthogonality in E satisfies one of the following conditions 1) homogeneity 2) additivity 3) x⊥Lpy implies x⊥Jy 4) x⊥Jy implies x⊥Lpy, then E is an abstract Euclidean space and there must be p=2. We also proved anR. C. James' result-If for every element x of a normed linear space E therecan be found a nonzero element orthogonal to x by Roberts' definition in each two dimensional linear subset containing x, then E is an abstract Euclidean space——which had not been proved. Finally, we point out that if one of the James′,Lp-,isosceles, Pythagorean and (α,β)-orthogonalities defined in E implies Roberts′ orthogonality then E is an abstract Euclidean space.  相似文献   

2.
关于非线性泛函的一个问题   总被引:2,自引:0,他引:2  
Suppose that H is a Hilbert space, D is a convex closed set inis a functioal, f(x)=1/2‖x‖2-g(x). Suppose that the minimum of f(x) withrespect to D is attained at x0∈D and f(x) has a bounded linear Gateaux differential at x0. In this paper we prove that f(x0) is a critical value of f(x) when and only when g′(x0)∈ID(x0)={(1-λ)x0+λy|y∈D.λ≥0}.  相似文献   

3.
Let Aφ(x)=∫GK(x,y)f(y,φ(y))dy, where G is a bounded closed domain in Euclidean space, K(x,y) is continuous on G×G, f(x,u) is continuous on G×R, and f(x,0)≡0. Set Gx={x|x∈G,K(x,y)≠0},Gy={y|y∈G,K(x,y)≠0},G1=Gx∩Gy≠φ.Let K1(x,y) be the restriction of K(x,y) on G1×G1,f1(x,u)be the restriction of f(x, u) on G1× R, and A1φ=∫G1K1(x,y)f1(y,φ1(y))dy, The main result of this paper is Theorem λ≠0 is an eigenvalue of A, if and only if λ is an eigenvalue of A1.  相似文献   

4.
The stability problems of the exponential (functional) equation on a restricted domain will be investigated, and the results will be applied to the study of an asymptotic property of that equation. More precisely, the following asymptotic property is proved: Let X be a real (or complex) normed space. A mapping f : X → C is exponential if and only if f(x + y) - f(x)f(y) → 0 as ||x|| + ||y|| → ∞ under some suitable conditions.  相似文献   

5.
二值回归模型中自变量误差的处理   总被引:1,自引:0,他引:1  
In this paper the binary regression model, in which the response Y is binary, i.e. Y takes the value 0 or 1 only, is considered. The conditional probability P{Y=1|X=x} is assumed to be of the form G(a0+a1x), where x is the measurement of the factor, a= (a0,a1)′ is the vector of the unknown parameter being estimated and G(a) = (1+ea)-1. The measurement x is assu-med to be contaminated when the value of x is out of certain limit. M-estimation is employed to estimate the unknown a of the model. In this paper, the consistent M-estimation is proved to be asymptotically normal and the optimal M-equation is obtained. Finally, a computation method is introduced to solve the M-equation and to get the optimal solution.  相似文献   

6.
关于集值系统x∈F(x,y),y∈G(x,y)解的存在性   总被引:2,自引:0,他引:2  
Let (E, ‖·‖) be a uniformly convex Banach space, X a nonempty compact and convex subset of E. Let F be a closed mapping of X×X into 2X, G a mapping of X×X into C(X). It is shown that if for any f∈C(X), x∈X, F(x,f(x)) is a closed and convex subset of X, and G(x,f(x)) is a continuous function and for any x,y1,y2∈X,H(x,G(x,y1),G(x,y2))≤‖y1-y2‖ then there exist X0,y0∈X such that X0∈F(x0,y0) and y0∈G(x0, y0).  相似文献   

7.
Let f(t) be a functiin defined on [a,b] and Let f(r-1)(t)(r≥2) be of bounded variation there. Then for any x∈[0,l] we have (?).It is shown that the expression given above has various consequences including those mentioned in [1], [2],[3], respectively. Also the result included in this note is a refined estimate fcr the remainder term of an asymptotic expansion of a kind of oscillatory integral (See (13) - (16)).  相似文献   

8.
In this note, we prove that, let f be a quasi-open, closed mapping from an M1-space x onto a q-space (or a space of pointwise countable type) Y, then y is an M1-space; which partially answers a classic problem. "Is the irreducible closed image of an M1-space M1?" (irreducible closed mapping→quasi-open mapping).  相似文献   

9.
Let f(x) be a periodic function of period 2π,|f(x)|and |f(x)|p integrable on [0,2π].It is said to be f∈HX1,if (∫0|f(x+h)-f(x)|pdx)1/p≤|h|.It is said to be f∈HX2,if (∫0|f(x+h)+f(x-h)-2f(x)|pdx)1/p≤2|h|.  相似文献   

10.
Let f(x)∈C[-1,1],Tn(x)=cos (n arccos x),Un(x)=(sin((n+1)arccosx))/(1-x2)1/2,Pn(x) be the Legendre polynomials of degree n. And let ω(t ) be a given modulus of continuity, Hω={f|ω(f,t)≤ω(t)}.A. K. Sharma and J. Tzimbalario(J. Appro. Th., 13(1975), 431-442) considered the operators Ln,p (f, x) (p= 0, 1, 2,3) and obtained some theorems.In this paper, we prove the following theorems.  相似文献   

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