共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
, , , . , . ,
, x(0,1),x2–j
,j=1,2,..., 2
n
. , ka
k
0 k k. , (0, 1) , , , , . , . 相似文献
3.
We consider (,,,)structures of parabolic type on hypersurfaces of dual spaces and study the rank of the affinor . We consider almost contact metric structures of parabolic type of the first kind on hypersurfaces of 4dimensional dual metric space. We study the properties of these structures and give examples of normal, integrable, and Sasakian parabolic structures. 相似文献
4.
Corrado Zanella 《Designs, Codes and Cryptography》1998,13(2):199-212
In this paper we deal with authentication systems in which one key is used to authenticate many source states. We answer a related question on the cardinalities of the intersections of quadrics in PG (d,q). We first generalize a class of geometric authentication systems, which has been introduced by Beutelspacher, Tallini and Zanella4. The source states are the lines through a special point N of PG (d,q) (the d-dimensional projective space over GF (q)). The keys are some hypersurfaces which have N as a nucleus ( N is a nucleus of if every line through N meets in exactly one point). The message belonging to a source state and a key is the unique point of intersection of the line with the hypersurface . We give the values of s for which the constructed authentication systems have a security which is comparable to the best allowed by a theoretical bound. In case the hypersurfaces are quadrics, we give further results on the security. To this end, we determine the greatest cardinality for the intersections of the finite Veronese varieties with the projective subspaces of any given dimension. Finally, we discuss a possible implementation. 相似文献
5.
6.
V. F. Kolchin 《Mathematical Notes》1977,21(5):386-394
It is shown that the conditional distributions of a number of characteristics of a branching process (t), (0)=m, under the condition that the number of total progeny m in this process is equal to n, coincide with the distributions of the corresponding characteristics of a generalized scheme of arrangement of particles in cells. In the case where the number of offsprings of a particle has the Poisson distribution, the characteristics of the branching process (t), (0)=1, under the condition that 1=n+1, coincide with the characteristics of a random tree. By using these connections we obtain in this article a series of limit theorems as n for characteristics of random trees and branching processes under the conditions that m=n.Translated from Matematicheskie Zametki, Vol. 21, No. 5, pp. 691–705, May, 1977. 相似文献
7.
C. S. Withers 《Probability Theory and Related Fields》1981,57(4):509-534
Summary This paper gives a flexible approach to proving the Central Limit Theorem (C.L.T.) for triangular arrays of dependent random variables (r.v.s) which satisfy a weak mixing condition called -mixing. Roughly speaking, an array of real r.v.s is said to be -mixing if linear combinations of its past and future are asymptotically independent. All the usual mixing conditions (such as strong mixing, absolute regularity, uniform mixing, -mixing and -mixing) are special cases of -mixing. Linear processes are shown to be -mixing under weak conditions. The main result makes no assumption of stationarity. A secondary result generalises a C.L.T. that Rosenblatt gave for strong mixing samples which are nearly second order stationary. 相似文献
8.
A general minimax theorem 总被引:2,自引:0,他引:2
Prof. Dr. A. Irle 《Mathematical Methods of Operations Research》1985,29(7):229-247
This paper is concerned with minimax theorems for two-person zero-sum games (X, Y, f) with payofff and as main result the minimax equality inf supf (x, y)=sup inff (x, y) is obtained under a new condition onf. This condition is based on the concept of averaging functions, i.e. real-valued functions defined on some subset of the plane with min {x, y}< (x, y)x, y} forx y and (x, x)=x. After establishing some simple facts on averaging functions, we prove a minimax theorem for payoffsf with the following property: Forf there exist averaging functions and such that for any x1, x2 X, > 0 there exists x0 X withf (x0, y) >
f (x1,y),f (x2,y))– for ally Y, and for any y1, y2 Y, > 0 there exists y0 Y withf (x, y0) (f (x, y1),f (x, y2))+. This result contains as a special case the Fan-König result for concave-convex-like payoffs in a general version, when we take linear averaging with (x, y)=x+(1–)y, (x, y)=x+(1–)y, 0 <, < 1.Then a class of hide-and-seek games is introduced, and we derive conditions for applying the minimax result of this paper.
Zusammenfassung In dieser Arbeit werden Minimaxsätze für Zwei-Personen-Nullsummenspiele (X, Y,f) mit Auszahlungsfunktionf behandelt, und als Hauptresultat wird die Gültigkeit der Minimaxgleichung inf supf (x, y)=sup inff (x, y) unter einer neuen Bedingung an f nachgewiesen. Diese Bedingung basiert auf dem Konzept mittelnder Funktionen, d.h. reellwertiger Funktionen, welche auf einer Teilmenge der Ebene definiert sind und dort der Eigenschaft min {x, y} < < (x, y)相似文献x, y} fürx y, (x, x)=x, genügen. Nach der Herleitung einiger einfacher Aussagen über mittelnde Funktionen beweisen wir einen Minimaxsatz für Auszahlungsfunktionenf mit folgender Eigenschaft: Zuf existieren mittelnde Funktionen und, so daß zu beliebigen x1, x2 X, > 0 mindestens ein x0 X existiert mitf (x0,y) (f (x 1,y),f (x2,y)) – für alley Y und zu beliebigen y1, y2 Y, > 0 mindestens ein y0 Y existiert mitf (x, y0) (f (x, y1),f (x, y 2))+ für allex X. Dieses Resultat enthält als Spezialfall den Fan-König'schen Minimaxsatz für konkav-konvev-ähnliche Auszahlungsfunktionen in einer allgemeinen Version, wenn wir lineare Mittelung mit (x, y)=x+(1–)y, (x, y)= x+(1–)y, 0 <, < 1, betrachten.Es wird eine Klasse von Suchspielen eingeführt, welche mit dem vorstehenden Resultat behandelt werden können.
9.
Resumé On étudie les hypersurfaces exceptionnelles pour les applications holomorphes de (n). On montre qu'une telle hypersurface n'est jamais lisse dès que son degré est plus grand que deux.
Exceptional hypersurfaces for holomorphic endomorphisms of (n) are studied. We prove that such an hypersurface is not smooth as soon as its degree is greater than two.相似文献
10.
Tomasz Rolski 《Probability Theory and Related Fields》1990,84(1):27-37
Summary We discuss in this paper a non-homogeneous Poisson process A driven by an almost periodic intensity function. We give the stationary version A
* and the Palm version A
0 corresponding to A
*. Let (T
i
,i) be the inter-point distance sequence in A and (T
i
0
,i) in A
0. We prove that forj, the sequence (T
i+j,i) converges in distribution to (T
i
0
,i). If the intensity function is periodic then the convergence is in variation. 相似文献
11.
Distributions having compact support are represented as the boundary value of Cauchy and Poisson integrals corresponding to tubular radial domains TC in n where C is an open convex cone. The Cauchy integral of U is shown to be an analytic function in TC which satifies a certain boundedness condition. All analytic functions in TC having this boundedness condition have a distributional boundary value which can be used to determine an distribution. The results are extended to vector valued distributions. 相似文献
12.
Sharad Sane 《Designs, Codes and Cryptography》2001,23(3):291-296
A proof of the following conjecture of Jungnickel and Tonchev on quasi-multiple quasi-symmetric designs is given: Let D be a design whose parameter set (v,b,r,k,) equals (v,sv,sk,k, s) for some positive integer s and for some integers v,k, that satisfy (v-1) = k(k-1) (that is, these integers satisfy the parametric feasibility conditions for a symmetric (v,k,)-design). Further assume that D is a quasi-symmetric design, that is D has at most two block intersection numbers. If (k, (s-1)) = 1, then the only way D can be constructed is by taking multiple copies of a symmetric (v,k, )-design. 相似文献
13.
Cheng -Tan Hsiao 《Probability Theory and Related Fields》1982,59(1):39-53
Summary LetU(x), x
d-|0}, be a nonnegative even function such that x
0U(x)1. In this paper, we consider an infinite system of stochastic process
t
(x); x
d with the following mechanism: at each sitex, after mean 1 exponential waiting time,
t(x) is replaced by a Gaussian random variable with mean
yx
t
(y) U(y-x) and variance 1. It is understood here that all the interactions are independent of one another. The behavior of this system will be investigated and some ergodic theorems will be derived. The results strongly depend whether
x
0
U(x)<1 or =1. 相似文献
14.
Thek-core of the setS
n
is the intersection of the convex hull of all setsA S with ¦SA¦<-k. The Caratheodory number of thek-core is the smallest integerf (d,k) with the property thatx core
kS, S
n
implies the existence of a subsetT S such thatx corekT and ¦T¦f (d, k). In this paper various properties off(d, k) are established.Research of this author was partially supported by Hungarian National Science Foundation grant no. 1812. 相似文献
15.
Summary In this paper we study the noncharacteristic Cauchy problem, ut–(a(x)ux)x=0, x(0, l), t.(0, T], u(0, t)=(t), ux(0,t)=0, 0tT, assuming only L for a. In the case of weak a priori bounds on u, we derive stability estimates on u of Hölder type in the interior and of logarithmic type at the boundary. Also the continuous dependence on a is considered.
Sunto Nel presente lavoro consideriamo il problema di Cauchy non ben posto ut= (a(x)ux)x, x(0, l), t(0, T), u(0, t)=(t), ux(0, t)=0, 0tT. Supponiamo che a sia misurabile e limitato inferiormente e superiormente da constanti positive. Introduciamo delle limitazioni a priori su u e dimostriamo la dipendenza continua di u rispetto al dato sia in (0, l)×(0, T) (di tipo hölderiano) sia per x=l (di tipo logaritmico). Consideriamo, inoltre, la dipendenza continua di u da a.相似文献
16.
Janet Heine Barnett 《Periodica Mathematica Hungarica》1995,30(3):171-176
It is consistent that 1(1,(:n))2 holds in any random extension for n finite and countable. 相似文献
17.
Daniel Neuenschwander 《Journal of Theoretical Probability》1995,8(1):165-174
A limit theorem due to J. Kuelbs and M. Ledoux, valid for dilatation-stable laws on type 2-Banach spaces, is carried over to stable laws on simply connected step 2-nilpotent Lie groupsG. We show that for products of i.i.d. random variables in the of attraction of a nondegenerate semigroup onG, where is a one-parameter automorphism group acting contracting onG, a certain intermediate trimming procedure, together with a suitable norming, always yields a nondegenerate centered Gaussian limit. 相似文献
18.
Héctor H. Cuenya 《Analysis Mathematica》2000,26(3):175-186
Let (, A, ) be a measure space, a function seminorm on M, the space of measurable functions on , and M
the space {f M : (f) < }. Every Borel measurable function : [0, ) [0, ) induces a function : M M by (f)(x) = (|f(x)|). We introduce the concepts of -factor and -invariant space. If is a -subadditive seminorm function, we give, under suitable conditions over , necessary and sufficient conditions in order that M
be invariant and prove the existence of -factors for . We also give a characterization of the best -factor for a -subadditive function seminorm when is -finite. All these results generalize those about multiplicativity factors for function seminorms proved earlier. 相似文献
19.
Živorad Tomovski 《Analysis Mathematica》2003,29(2):165-170
In this paper equivalent classes of the classes M'
and S'
p
r, p >1, 0,r {0,1,2,...,[]} defined by Sheng [5] are obtained. Then it is shown that the classes of Fourier coefficients S
p, S'
p(case r==0) and S
p(), p>1, defined by . V. Stanojevi, V. B. Stanojevi Sheng and the author of the present note are identical. As a corollary of this result, the L
1-estimate for cosine series, obtained in [10], is refined. 相似文献
20.
Mark Skandera 《Journal of Algebraic Combinatorics》2004,20(2):195-211
Let
I,I be the minor of a matrix which corresponds to row set I and column set I. We give a characterization of the inequalities of the form
I,I
K,K
J,J
L,L
which hold for all totally nonnegative matrices. This generalizes a recent result of Fallat, Gekhtman, and Johnson. 相似文献