共查询到20条相似文献,搜索用时 62 毫秒
1.
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
2.
K. Tandori 《Analysis Mathematica》1980,6(2):157-164
. . . : sn(x) — , n-(, 1)- n
L
2. , . , :
a
k
l
2
n
() [0,1] , (*) , (**) .
a
k
l
2
u
n
() [0,1] , (**), (*) . 相似文献
3.
We show that for any simple piecewise Ljapunov contour there exists a power weight such that the essential norm |S
| in the spaceL
2(, ) does not depend on the angles of the contour and it is given by formula (2). All such weights are described. For the union =12 of two simple piecewise Lyapunov curves we prove that the essential norm |S
| inL
2() is minimal if both 1 and 2 are smooth in some neighborhoods of the common points. It is the case when the norm |S
| in the spaceL
2() as well as inL
2(, ) does not depend on the values of the angles and it can be calculated by formula (5). 相似文献
4.
Let G be a finite permutation group on a set with no fixed points in and let m and k be integers with 0 < m < k. For a finite subset of the movement of is defined as move() = maxgG| g \ |. Suppose further that G is not a 2-group and that p is the least odd prime dividing |G| and move() m for all k-element subsets of . Then either || k + m or k (7m – 5) / 2, || (9m – 3)/2. Moreover when || > k + m, then move() m for every subset of . 相似文献
5.
E. A. Riss 《Journal of Mathematical Sciences》1992,61(1):1907-1911
The fundamental result: if and v are two finite Borel measures, defined in the spaceL
p[0, 1] (1p<) or in C(K) (K is a metric compactum without isolated points), then from the equalities (B)=v(B) for all balls B of radius 1 there follows that =v. In addition, in the spaces C(K) and p (1p<) from the inequalities (B) v(B) there follows that v.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova Akademii Nauk SSSR, Vol. 177, pp. 122–128, 1989. 相似文献
6.
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.
7.
Characterization theorem of generalized polynomial of best approximation having bounded coefficients
Shusheng Xu 《应用数学学报(英文版)》1989,5(4):361-366
Let the set of generalized polynomials having bounded coefficients beK={p=
jgj.
j
j
j,j=1, 2, ...,n}, whereg
1,g
2, ...,g
n are linearly independent continuous functions defined on the interval [a, b],
j,
j are extended real numbers satisfying
j<+,
j>-, and
j
j. Assume thatf is a continuous function defined on a compact setX [a, b]. This paper gives the characterization theorem forp being the best uniform approximation tof fromK, and points out that the characterization theorem can be applied in calculating the approximate solution of best approximation tof fromK. 相似文献
8.
In-Suk Wee 《Probability Theory and Related Fields》1990,85(4):469-488
Summary Let {X
t
} be a 1 process with stationary independent increments and its Lévy measurev be given byv{yy>x}=x
–L
1
(x), v{yy<–x}=x
–L
2
(x) whereL
1,L
2 are slowly varying at 0 and and 0<1. We construct two types of a nondecreasing functionh(t) depending on 0<<1 or =1 such that lim inf
a.s. ast 0 andt for some positive finite constantC.This research is partialy supported by a grant from Korea University 相似文献
9.
M. S. Sgibnev 《Mathematical Notes》1977,22(5):916-920
Let {n} be a sequence of identically distributed independent random variables,M1=<0,M
1
2
<;S
0=0,S
n
=1+2,+...+
n, n1;¯ S=sup {S
n
n=0.} The asymptotic behavior ofP(¯ St) as t is studied. If
t
P
(1x dx=0((t)), thenP(¯ St)– 1/¦¦
t
P (1x dx=0((t)) (t) is a positive function, having regular behavior at infinity.Translated from Matematicheskie Zametki, Vol. 22, No. 5, pp. 763–770, November, 1977.The author thanks B. A. Rogozin for the formulation of the problem and valuable remarks. 相似文献
10.
Karl Dilcher 《Aequationes Mathematicae》1994,48(1):55-85
Summary We study a class of generalized gamma functions
k
(z) which relate to the generalized Euler constants
k
(basically the Laurent coefficients of(s)) as (z) does to the Euler constant. A new series expansion for
k
is derived, and the constant term in the asymptotic expansion for log
k
(z) is studied in detail. These and related constants are numerically computed for 1 k 15. 相似文献
11.
On the Eigenvalues and Eigenfunctions of the Sturm--Liouville Operator with a Singular Potential 总被引:1,自引:0,他引:1
In this paper we consider the Sturm--Liouville operators generated by the differential expression -y+q(x)y and by Dirichlet boundary conditions on the closed interval [0,]. Here q(x) is a distribution of first order,, i.e., q(x)dx L
2[0,]. Asymptotic formulas for the eigenvalues and eigenfunctions of such operators which depend on the smoothness degree of q(x) are obtained. 相似文献
12.
We investigate the problem of the boundedness of the following recurrence sequence in a Banach space B:
where |y
n} and |
n
} are sequences bounded in B, and A
k, k 1, are linear bounded operators. We prove that if, for any > 0, the condition
is satisfied, then the sequence |x
n} is bounded for arbitrary bounded sequences |y
n} and |
n
} if and only if the operator
has the continuous inverse for every z C, |z| 1. 相似文献
13.
A code
is called (t, 2)-identifying if for all the words x, y(x y) and
the sets (B
t
(x) B
t
(y)) C and
are nonempty and different. Constructions of such codes and a lower bound on the cardinality of these codes are given. The lower bound is shown to be sharp in some cases. We also discuss a more general notion of
-identifying codes and introduce weakly identifying codes. 相似文献
14.
In the present paper we shall consider an application of simple non-polynomial splines to a numerical solution of a weakly singular two-point boundary value problem:x
–
(x
y)=f(x,y), (0<x1) subject toy(0)=0,y(1)=c
1(1) ory(0)=c
2,y(1)=c
3(0<<1). Our collocation method gives a continuously differentiable approximation and isO(h
2)-convergent. 相似文献
15.
A. Yu. Šadrin 《Analysis Mathematica》1986,12(3):175-184
. L
p
, 0<p<, . , f, {E
n
(f)
p
}
1
p>0 .
The author expresses his thanks to S. B. Stekin for the attention he has paid to this work. 相似文献
The author expresses his thanks to S. B. Stekin for the attention he has paid to this work. 相似文献
16.
D. V. Millionshchikov 《Mathematical Notes》2005,77(1-2):61-71
The cohomology H* (G/,) of the de Rham complex *(G/) of a compact solvmanifold G/ with deformed differential d = d + , where is a closed 1 -form, is studied. Such cohomologies naturally arise in Morse-Novikov theory. It is shown that, for any completely solvable Lie group G containing a cocompact lattice G, the cohomology H*(G/, ) is isomorphic to the cohomology H*(
) of the tangent Lie algebra
of the group G with coefficients in the one-dimensional representation :
defined by () = (). Moreover, the cohomology H
*(G/,) is nontrivial if and only if -[] belongs to a finite subset
of H
1(G/,) defined in terms of the Lie algebra
.Translated from Matematicheskie Zametki, vol. 77, no. 1, 2005, pp. 67–79.Original Russian Text Copyright © 2005 by D. V. Millionshchikov.This revised version was published online in April 2005 with a corrected issue number. 相似文献
17.
Let LSC(X) be the set of the proper lower semicontinuous extended real-valued functions defined on a metric spaceX. Given a sequence f
n in LSC(X) and a functionf LSC(X), we show that convergence of f
n tof in several variational convergence modes implies that for each , the sublevel set at height off is the limit, in the same variational sense, of an appropriately chosen sequence of sublevel sets of thef
n, at height
n
approaching . The converse holds true whenever a form of stability of the sublevel sets of the limit function is verified. The results are obtained by regarding a hyperspace topology as the weakest topology for which each member of an appropriate family of excess functionals is upper semicontinuous, and each member of an appropriate family of gap functionals is lower semicontinuous. General facts about the representation of hyperspace topologies in this manner are given. 相似文献
18.
Youngmee Kwon 《Probability Theory and Related Fields》1995,101(2):211-226
Summary In this paper, the object of study is reflected Brownian motion in a cone ind-dimensions (d3) with nonconstant oblique reflection on each radial line emanating from the vertex of the cone. The basic question considered here is When is this process a semimartingale?. Conditions for the existence and uniqueness of the process for which the vertex is an instantaneous state were given by Kwon, which is resolved in terms of a real parameter depending on the cone and the direction of reflection. It is shown that starting from any point of the cone, the process is a semimartingale if < 1, + 0 and not a semimartingale if < < 2.This research is supported by KOSEF grant 941-0100-011-1 相似文献
19.
20.
We show that the r-dominated polynomials on p(2 p ) are integral on 1, and give examples proving that the converse is not true. We characterize when the 2-homogeneous, diagonal polynomials on p(1 < p ) are r-dominated. We prove that, unlike the linear case, there are nuclear polynomials which are not 1-dominated.Received: 6 June 2004; revised: 28 September 2004 相似文献