共查询到20条相似文献,搜索用时 109 毫秒
1.
引入了主算子为n次积分C半群生成元的线性非齐次抽象柯西问题强解的概念,讨论了相应抽象柯西问题存在强解的一些充分必要条件及强解的表示式.并给出了一个例子验证结果. 相似文献
2.
给出了n次积分C半群的几个性质及其证明,讨论了它与一类抽象柯西问题存在强解的关系及强解的表示式. 相似文献
3.
一类弱耗散双组份Hunter-Saxton系统的爆破与爆破率 总被引:1,自引:0,他引:1
张剑梅 《数学的实践与认识》2014,(5)
研究了一类周期弱耗散双组份Hunnter-Saxton系统的爆破现象.首先,给出了此类Hunnter-Saxton系统解的局部适定性及其精确的爆破机制;其次,证明了在一定的初始值下Hunnter-Saxton系统强解的几个爆破结果;最后,给出了HunnterSaxton系统强解的爆破率. 相似文献
4.
5.
主要研究了一类带有非牛顿位势的可压缩Navier-Stokes方程:其中粘性系数μ依赖于密度ρ,Φ是非牛顿位势.证明了上述问题的强解的存在性.在相容性条件下,得到了强解的唯一性. 相似文献
6.
方程u_(tt)=u_(xxt)+σ(u_x)_x的初边值问题、周期边界问题与初值问题 总被引:1,自引:0,他引:1
本文用Galerkin方法研究了方程的初边值问题,周期边界问题及初值问题,在σ(Z)∈C~1,σ'(Z)下方有界的条件下,得到了整体强解的存在和唯一性,而在σ及初值函数满足一定的光滑性条件下,得到强解的相应的光滑性;最后讨论了解的渐近性质。 相似文献
7.
给出了一类半线性双温度热传导方程的初边值问题整体强解的存在条件,利用位势井方法证明了整体强解的存在性定理,且证明了方程的解或解对X的某些导数的L^2模估计式. 相似文献
8.
本文证明了无界区域上三维趋化模型初边值问题全局小强解的存在性.此外还研究了系统在半空间上的收敛性,证明了在H~1中,强解以(1+t)-3/4速率收敛到其相应的稳态解. 相似文献
9.
本文研究一类非线性高阶发展方程ua-△ui,-0△ua-△i=f(u)整体强解的渐近行为,利用ω极限紧方法得到了整体强解的全局吸引子 的存在性, 在D(A)×D(A)不变、紧,并且按D(A)×D(A)的范数吸引D(A)×D(A)中的任意有界集,其中非线性项f满足临界指数增长条件. 相似文献
10.
11.
For stable FIFO GI/GI/s queues, s ≥ 2, we show that finite (k+1)st moment of service time, S, is not in general necessary for finite kth moment of steady-state customer delay, D, thus weakening some classical conditions of Kiefer and Wolfowitz (1956). Further, we demonstrate that the conditions required
for E[D
k]<∞ are closely related to the magnitude of traffic intensity ρ (defined to be the ratio of the expected service time to the
expected interarrival time). In particular, if ρ is less than the integer part of s/2, then E[D] < ∞ if E[S3/2]<∞, and E[Dk]<∞ if E[Sk]<∞, k≥ 2. On the other hand, if s-1 < ρ < s, then E[Dk]<∞ if and only if E[Sk+1]<∞, k ≥ 1. Our method of proof involves three key elements: a novel recursion for delay which reduces the problem to that of a
reflected random walk with dependent increments, a new theorem for proving the existence of finite moments of the steady-state
distribution of reflected random walks with stationary increments, and use of the classic Kiefer and Wolfowitz conditions.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
12.
LetLbe a Moufang loop of odd orderpαqα11···qnαnwherepandqiare primes with 3 ≤ p < q1 < ··· < qnand αi ≤ 2. In this paper, we prove thatLis a group ifpandqiare primes with 3 ≤ p < q1 < ··· < qn: (i) α ≤ 3, or (ii) α ≤ 4,p ≥ 5. 相似文献
13.
Pierre Bousquet 《Journal d'Analyse Mathématique》2007,102(1):311-346
We are interested in the location of the singularities of maps u ∈ W
s,p
(S
N
, S
1) when 1 ≤ sp and 1 < sp < 2. To this end, we consider the distributional Jacobian. We show that the range of this operator on W
s,p
(S
N
, S
1) is the closure in W
s−2,p
⋂ W
−1,sp
of the set of N − 2-currents defined as the integration on smooth oriented N − 2-dimensional boundaryless submanifolds. 相似文献
14.
The fundamental theorems on conjugate functions are shown to be valid for weak1 Dirichlet algebras. In particular the conjugation operator is shown to be a continuous map of Lp to Lp for 1 < p < ∞, to be a continuous map of L1 to Lp, 0 < p < 1, and to map functions in L∞ to exponentially integrable functions. These results allow a number of results for Dirichlet algebras to be extended to weak1 Dirichlet algebras. 相似文献
15.
J.S Byrnes 《Journal of Approximation Theory》1973,9(4):373-379
We compare the degree of approximation to L2(?π, π) by nth degree trigonometric polynomials, with the degree of approximation by trigonometric n-nomials, which are linear combinations, with constant (complex) coefficients, of any 2n + 1 members of the sequence {exp (ikx)}, ? ∞ < k < ∞. 相似文献
16.
Stephen James Wolfe 《Stochastic Processes and their Applications》1982,12(3):301-312
Let B1, B2, ... be a sequence of independent, identically distributed random variables, letX0 be a random variable that is independent ofBn forn?1, let ρ be a constant such that 0<ρ<1 and letX1,X2, ... be another sequence of random variables that are defined recursively by the relationshipsXn=ρXn-1+Bn. It can be shown that the sequence of random variablesX1,X2, ... converges in law to a random variableX if and only ifE[log+¦B1¦]<∞. In this paper we let {B(t):0≦t<∞} be a stochastic process with independent, homogeneous increments and define another stochastic process {X(t):0?t<∞} that stands in the same relationship to the stochastic process {B(t):0?t<∞} as the sequence of random variablesX1,X2,...stands toB1,B2,.... It is shown thatX(t) converges in law to a random variableX ast →+∞ if and only ifE[log+¦B(1)¦]<∞ in which caseX has a distribution function of class L. Several other related results are obtained. The main analytical tool used to obtain these results is a theorem of Lukacs concerning characteristic functions of certain stochastic integrals. 相似文献
17.
该文研究了Lp(Ω,∑,μ; Lq(X, A,ν)) (2≤q
p (Ω,∑,μ; Lq(X,A,ν))(1
相似文献
18.
该文研究椭圆型方程
{Δpu+m|u|p-2u-Δqu+n|u|q-2u=g(x, u), x∈RN,
u∈ W1, p(RN)∩W1, q(RN)
弱解在全空间RN上的衰减性, 其中m, n ≥ 0, N≥3, 1 < q < p < N, g(x, u)关于u满足类渐近线性. 证明了该方程的
弱解在无穷远处关于|x|呈指数衰减性. 相似文献
19.
Andreas Fr?hlich 《Annali dell'Universita di Ferrara》2000,46(1):11-19
We consider weights of Muckenhoupt classA
q, 1<q<∞. For a bounded Lipschitz domain Ω⊂ℝn we prove a compact embedding and a Poincaré inequality in weighted Sobolev spaces. These technical tools allow us to solve
the weak Neumann problem for the Laplace equation in weighted spaces on ℝn, ℝn
+, on bounded and on exterior domains Ω with boundary of classC
1, which will yield the Helmholtz decomposition ofL
ω
q(Ω)n for general ω∈A
q. This is done by transferring the method of Simader and Sohr [4] to the weighted case. Our result generalizes a result of
Farwig and Sohr [2] where the Helmholtz decomposition ofL
ω
p(Ω)n is proved for an exterior domain and weights of Muckenhoupt class without singularities or degeneracies in a neighbourhood
of ϖΩ.
Sunto In questo lavoro consideriamo dei pesi della classe di MuckenhouptA q, 1<q<∞. Per un dominio limitato lipschitziano Ω⊂ℝn, dimostriamo una immersione compatta ed una disuguaglianza di Poincaré in spazi di Sobolev con peso. Questa tecnica ci consente di risolvere il problema debole di Neumann per l’equazione di Laplace in spazi pesati in ℝn, ℝn + in domini limitati ed in domini esterni con frontiera di classeC 1, che conduce alla decomposizione di Helmholtz diL ω q(Ω)n per un qualsiasi ω∈A q. Il risultato è ottenuto trasferendo il metodo di Simader e Sohr [4] al caso pesato. Quello qui presente estende un risultato di Farwig e Sohr [2] dove la decomposizione di Helmholtz diL ω q(Ω)n è dimostrata per domini esterni e pesi della classe di Muckenhoupt privi di singolarità in un intorno di ϖΩ.相似文献
20.
This paper is a continuation of [1], we study the approximation of the function classes [(S1G L)\tilde]\widetilde{S_1^\Gamma L} , S 1 Λ H in Lq metric (1≤q<∞) by entire functions whose spectrals lie in step hyperbolic crosses and obtain the asymptotic estimates of these quantities. 相似文献