共查询到20条相似文献,搜索用时 31 毫秒
1.
J. Löfström 《Annali di Matematica Pura ed Applicata》1982,132(1):189-214
Summary Let W
p
m
(w) be the Sobolev space of functions f such thatD
fL
p(w) for ||m. 相似文献
2.
Kevin E. Osondu 《Semigroup Forum》1979,17(1):139-152
Let S be a cancellative semigroup which is a semilattice of left reversible semigroups S, . This article studies the relationship between the group of quotients G of S and the groups of quotients G of S, . It is shown that G is the maximum group homomorphic image of an inverse semigroup which is a semilattice of groups G (up to isomorphism).The technique used here which involves the use of Ore's quotients also applies to the study of the maximum group homomorphic image of a semigroup which is a semilattice of inverse semigroups. 相似文献
3.
G. S. Karkarashvili 《Journal of Mathematical Sciences》1993,66(3):2236-2242
We consider numerical solution of an integro-differential equation with nonsmooth initspaial values. Unique solvability in Sobolev spaceW
2
(0, 1), =1,2, is proved. We establish the rate of convergence of the approximate solution to the exact solution in fractional spacesW
2
+1
, 01, with approximation order O(h
++1/2
) for 01/2 andO(h
+1
|ln h|1/2, for 1/2 #x2264;1.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 64, pp. 8–16, 1988. 相似文献
4.
Summary We prove the following theorem: «Given 0<1, the (C, )-means of a sequence of i.i.d. random variables X
n converge a.s. iff E|X
n|1/<.» For 1/2<1 and 0<<1/2 this result is essentially known. We give here a proof of the case =1/2; an important tool is a theorem of Hsu and Robbins [5]. 相似文献
5.
V. V. Chernikov 《Mathematical Notes》1972,11(2):141-144
Upper and lower bounds are obtained for the radius of-convexity, R, of the schlicht within ¦z¦< 1 functions g(z), g(0)=0, and g(0)=1, for values ranging from 0 to 0.313.... The exact value of R is determined for 0.313... < 1. The results constitute the solution to a problem recently posed by the Roumanianmathematician P. T. Mocanu [1].Translated from Matematicheskie Zametki, Vol. 11, No. 2, pp. 227–232, February, 1972. 相似文献
6.
K. Väänänen 《Monatshefte für Mathematik》1989,108(2-3):219-227
We shall give a further application of Hermite-Mahler polynomials to the consideration ofp-adic exponential function. An effective lower bound is obtained for max {| – |
p
,P(e
)|
p
}, where is an algebraic number satisfying ||
p
<p
–/(p–1), and 0 is ap-adic number with | |
p
depending on the degree of the polynomialPZ[y]. The bound obtained implies the transcendence ofe
if ap-adic number satisfying 0 < ||
p
<p
–/(p–1) is algebraic or can be well approximated by algebraic numbers.This work was carried out while the author was a research fellow of the Alexander von Humboldt Foundation. 相似文献
7.
E. M. Matveev 《Mathematical Notes》1996,59(3):293-297
In this note we show that in the well-known Dobrowolski estimate lnM() (ln lnd/ lnd)3,d , where is a nonzero algebraic number of degreed that is not a root of unity andM() is its Mahler measure, the parameterd can be replaced by the quantity=d/()
1/d, where () is the modulus of the discriminant of. To this end, must satisfy the condition deg
p=deg for any primep.Translated fromMatematicheskie Zametki, Vol. 59, No. 3, pp. 415–420, March, 1996. 相似文献
8.
Susanne Beer 《manuscripta mathematica》1969,1(2):201-209
Let k be a field which is locally compact with respect to a valuation ||, let X denote the subset X={ k, ||1}. This paper is concerned with sequences of elements of X with respect to the theory of uniform distribution. Let DN() denote the discrepancy of the sequence =(xn). It is proved that for archimedian valuations with a certain constant for every sequence . In the non-archimedian case there exist sequences with
. 相似文献
9.
Michel Hébert 《Applied Categorical Structures》2001,9(6):595-623
We give concrete versions of the characterizations of locally -presentable (resp. -generated) categories as categories of models of (resp. weakly) -ary limit-theories and of (resp. weakly) -ary essentially algebraic theories. By concrete we mean that starting with a category of -structures, the theories obtained are extensions of the original ones, and the equivalences of categories are concrete isomorphisms. -presentable and -generated objects are also investigated from this viewpoint. 相似文献
10.
S. V. Solov'ev 《Journal of Mathematical Sciences》1982,20(4):2367-2369
We consider the (&, )-fragment of the intuitionistic propositional calculus. It is proved that under the standard transformation of a Gentzen derivation into a natural derivation(), the length of (())22·length(
). There is constructed a sequence of Gentzen derivations of length i, for which the length of ((
i))21/3·length(i), which shows that the upper bound obtained is not too weak.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 88, pp. 192–196, 1979. 相似文献
11.
We consider the boundary-value problem u
tt + u
t + (1 + cos2)sin u =2
u
xx, u
x|x=0=ux|x==0, where 0<1, =(1+)t, ,> 0, and the sign of is arbitrary. It is proved that for an appropriate choice of the external parameters and and for sufficiently small the number of exponentially stable solutions 2-periodic in can be made equal to an arbitrary predefined number. 相似文献
12.
A. A. Klunnik 《Journal of Mathematical Sciences》1992,58(5):391-395
A general approach is proposed to the interpolation of x
-analytical functions of a complex variable with an arbitrary –,+[Basis
x
-analytical functions whose imaginary pan is a polynomial in x, and y are obtained in explicit form.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 58, pp. 3–9, 1986. 相似文献
13.
Somaraju Vempaty R. Balasubramanian 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1982,33(6):763-771
Steady, linear hydromagnetic boundary layer at the free surface of a rotating baroclinic fluid is analysed under Boussinesq approximation. The flow is driven by the buoyancy forces which exist due to the density variations associated with baroclinicity. Meridional circulations of mass flux and electric current flux occur due to the boundary layer suction as well as due to the hydromagnetic effects. The boundary layer suction dominates and the dynamics of the flow reduce to that of nonmagnetic case for 2<O(E), whereE is the Ekman number and 2 (=B
0
2
/) is the magnetic interaction parameter, which represents the ratio of hydromagnetic to Coriolis forces. When 2>O(E), meridional circulation induced in the interior due to hydromagnetic effects is stronger than that can be supported by the boundary layer. The electric current flux through the interior is stronger for any value of than that can be supported by the boundary layer. Further it is argued that hydromagnetic effects suppress the laminated flow (v/z0) in the interior. As a result, the meridional circulations are strong when =O(1).
Zusammenfassung Die stationäre lineare hydromagnetische Grenzschicht an der freien Oberfläche eines rotierenden, baroklinischen Fluids wird mit Hilfe der Boussinesq-Näherung untersucht. Die Strömung wird durch die Auftriebskräfte angetrieben, die durch die baroklinischen Dichte-Variationen verursacht werden. Die meridionale Zirkulation des Massenstromes und des elektrischen Stromes wird durch die Grenzschicht-Saugwirkung und durch hydromagnetische Effekte erzeugt. Die Grenzschicht-Saugwirkung dominiert und die Strömung reduziert sich auf den nicht-magnetischen Fall für 2<O(E); dabei istE die Ekman-Zahl und 2 (=B 0 2 /) ist der magnetische Kopplungs-Parameter, der das Verhältnis der hydromagnetischen zu den Coriolis-Kräften gibt. Wenn 2>O(E) ist, wird die meridionale Zirkulation, die durch hydromagnetische Effekte erzeugt worden ist, stärker als die, welche durch Grenzschichten erzeugt werden kann. Der elektrische Strom im Innern ist für alle Werte von größer als der Wert den die Grenzschicht verursacht. Weiterhin wird gezeigt, daß hydromagnetische Effekte die Laminal-Strömung (v/z0) im Innern unterdrückt. Es ergibt sich, daß die meridionalen Zirkulationen stark sind für =O(1).相似文献
14.
N. Phan-Thien 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1981,32(5):609-615
It is shown that a similarity solution to the Rayieigh flow problem for a generalized Newtonian fluid exists if the fluid boundary (y=0) is given a velocityU(t) t
1/2. Furthermore, if the fluid is of the power-law type then similarity solutions exist ifU(t) t
(orU(t) e
t), where is any real number.
Zusammenfassung Eine Methode wird aufgezeigt, wonach eine Ähnlichkeitslösung für das Rayleigh Strömungsproblem für eine allgemeine Newtonische Flüssigkeit besteht, falls der Flüssigkeitsgrenze (y=0) eine GeschwindigkeitU (t) t 1/2 zugeordnet wird. Für Flüssigkeiten von Potenz-Gesetz-Charakter gibt es außerdem Ähnlichkeitslösungen, fallsU(t) t (orU(t) e t) gilt, wobei eine beliebige reelle Zahl darstellt.相似文献
15.
B. B. Bhattacharyya X. Li M. Pensky G. D. Richardson 《Annals of the Institute of Statistical Mathematics》2000,52(1):71-83
The limiting distribution of the normalized periodogram ordinate is used to test for unit roots in the first-order autoregressive model st= s-1,t+s,t-1- s-1,t-1+st. Moreover, for the sequence
n
= e
c/n
,
n
= e
d/n
of local Pitman-type alternatives, the limiting distribution of the normalized periodogram ordinate is shown to be a linear combination of two independent chi-square random variables whose coefficients depend on c and d. This result is used to tabulate the asymptotic power of a test for various values of c and d. A comparison is made between the periodogram test and a spatial domain test. 相似文献
16.
Bernard Badzioch 《K-Theory》1999,16(1):29-34
We prove that for an arbitrary endomorphism of a ring R the group K1(R[t]) splits into the direct sum of K1(R) and Ñil (r;). Moreover, for any such R and Ñil (R; ) is isomorphic to Ñil (R ; ) for some ring R with : R R – an isomorphism. 相似文献
17.
Torben Maack Bisgaard 《Analysis Mathematica》2001,27(1):37-54
For >2, let Q
+() be the infimum of those q>0 for which the function n epn is positive definite on N
0 for every pq. We shall prove that Q
+()0 as 2. 相似文献
18.
19.
An investigation of the behavior of the coefficents Aj and j in the radiation lifetime equation j=Aje–j with variation of the starting structure of polycaprolactam has revealed the structure-sensitivity of j and the structure-insensitivity of Aj. This and the fact that j is proportional to the structure-sensitive coefficient in the equation for the lifetime without irradiation, together with the previous experimental data, provide a basis for the development of a theory of the mechanism of polymer fracture in the presence of UV radiation and throw light on the physical significance of the coefficients Aj and j.A. F. Ioffe Physicotechnical Institute, Academy of Sciences of the USSR, Leningrad. Translated from Mekhanika Polimerov, No. 4, pp. 636–641, July–August, 1969. 相似文献
20.
V. A. Pokhilevich 《Ukrainian Mathematical Journal》1991,43(6):761-768
In the open unit disk E={z, ¦z¦<1} we consider the class of regular functions q(z) = 1 + 2(1 = )e1zn + 2pn+kzn+k + ..., Re q(z)>, , [0, 1), [0, 2] and fixed, n, kN; fixing zE, we construct the range of the functional I0=q(z). We find an analog of V. A. Zmorovich's variational formula for the expression zp'(z) and point out some applications.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 43, No. 6, pp. 813–820, June, 1991. 相似文献