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81.
Feng Dai 《Constructive Approximation》2005,22(3):417-436
Let $\sigma_k^\delta$ denote the Cesaro means of order $\delta > -1$ of the spherical harmonic expansions on the unit sphere $S^{d-1}$, and let $E_j(f, H^1)$ denote the best approximation of $f$ in the Hardy space $H^1(S^{d-1})$ by spherical polynomials of degree at most $j$. It is known that $\lambda:= (d-2)/2$ is the critical index for the summability of the Cesaro means on $H^1(S^{d-1})$. The main result of this paper states that, for $ f\in H^1(S^{d-1})$, $$\sum_{j=0}^N \f 1{j+1} \|\sigma_j^\lambda (f) -f\|_{H^1}\approx \sum_{j=0}^N \f 1{j+1} E_j(f, H^1),$$ where “$\approx$” means that the ratio of both sides lies between two positive constants independent of $f$ and $N$. 相似文献
82.
Bruce Reed 《Discrete Applied Mathematics》2008,156(7):1150-1156
We discuss some new and old results about skew partitions in perfect graphs. 相似文献
83.
84.
该文利用修正的带权 K- 泛函K2σ f, t2)w,p, 考虑Gamma算子在Lp~ (1≤p ≤∞)空间带权同时逼近, 给出了它的 B -型强逆不等式. 相似文献
85.
We use kernel density with correction of boundary effects to study the strong stability of the M/M/1 system after perturbation of arrival flow (respectively service times), to evaluate the proximity of G/M/1 (respectively M/G/1) and M/M/1 systems when the distribution G is unknown. Simulation studies are performed to support the results. 相似文献
86.
In this note, a small gap is corrected in the proof of H.K. Xu [Theorem 3.3, A regularization method for the proximal point
algorithm, J. Glob. Optim. 36, 115–125 (2006)], and some strict restriction is removed also.
相似文献
87.
88.
We study the existence of non-collision periodic solutions for second order singular dynamical systems. The repulsive case and the attractive case are dealt with using a unified topological approach. The proof is based on a well-known fixed point theorem for completely continuous operators, involving a new type of cone. We do not need to consider so-called strong force conditions. Moreover, for the repulsive case, the critical case can be covered. Recent results in the literature, even in the scalar case, are complemented, generalized and improved. 相似文献
89.
Lascar described E
KP
as a composition of E
L
and the topological closure of E
L
(Casanovas et al. in J Math Log 1(2):305–319). We generalize this result to some other pairs of equivalence relations. Motivated
by an attempt to construct a new example of a non-G-compact theory, we consider the following example. Assume G is a group definable in a structure M. We define a structure M′ consisting of M and X as two sorts, where X is an affine copy of G and in M′ we have the structure of M and the action of G on X. We prove that the Lascar group of M′ is a semi-direct product of the Lascar group of M and G/G
L
. We discuss the relationship between G-compactness of M and M′. This example may yield new examples of non-G-compact theories.
The first author is supported by the Polish Goverment grant N N201 384134. The second author is supported by the Polish Goverment
grant N201 032 32/2231. 相似文献
90.
We define the notion of weak pseudocompactness for frames and present several characterizations. Among them are characterizations
in terms of strong inclusions, uniformities and cozero bases. Noteworthy is the fact that these internal characterizations
are not translated from characterizations of weakly pseudocompact spaces.
相似文献