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61.
Jan Andres Tom Fürst Karel Pastor 《Journal of Mathematical Analysis and Applications》2008,340(2):1132-1144
A full analogy of the celebrated Sharkovsky cycle coexistence theorem is established for lower semicontinuous (multivalued) maps on metrizable linear continua. This result is further extended to triangular maps. 相似文献
62.
Gert de Cooman Matthias C.M. Troffaes Enrique Miranda 《Journal of Mathematical Analysis and Applications》2008,340(2):982-999
This paper deals with n-monotone functionals, which constitute a generalisation of n-monotone set functions. Using the notion of exactness of a functional, we introduce a new notion of lower and upper integral which subsumes as particular cases most of the approaches to integration in the literature. As a consequence, we can characterise which types of integrals can be used to calculate the natural extension (the lower envelope of all linear extensions) of a positive bounded charge. 相似文献
63.
Highly monodisperse polymethylmethacrylate (PMMA) microparticles crosslinked with carboxylic group-containing urethane acrylates
(CUA) were produced by simple dispersion polymerization in methanol solution. In contrast to conventional crosslinkers, the
CUA employed as a crosslinker was excellent for maintaining the monodispersity of PMMA microparticles even at moderate crosslinker
concentrations (to about 5 wt%). It was believed that the CUA helped form the monomer-swellable surface of primary particles,
because of the structurally long tetramethylene oxide groups in the molecule. Carboxylic groups in the molecular backbone
resulted in larger primary particles by increasing the solubility of the monomer mixture in the medium. Owing to these larger
primary particles, the crosslinked PMMA particles showed lower polymerization rates than the linear ones during particle growth.
However, at high CUA concentrations (about 10 wt%), bimodal distributions were observed. This was attributed to the high crosslinking
density of the primary particle surfaces. Therefore, monomer diffusion toward the polymer phase was restricted, resulting
in more favorable secondary nucleation in the medium.
Received: 12 May 1998 Accepted: 19 August 1998 相似文献
64.
The overlay of 2≤m≤d minimization diagrams of n surfaces in ℝ
d
is isomorphic to a substructure of a suitably constructed minimization diagram of mn surfaces in ℝ
d+m−1. This elementary observation leads to a new bound on the complexity of the overlay of minimization diagrams of collections
of d-variate semi-algebraic surfaces, a tight bound on the complexity of the overlay of minimization diagrams of collections of
hyperplanes, and faster algorithms for constructing such overlays. Further algorithmic implications are discussed.
Work by V. Koltun was supported by NSF CAREER award CCF-0641402.
Work by M. Sharir was supported by NSF Grants CCR-00-98246 and CCF-05-14079, by a grant from the Israeli Academy of Sciences
for a Center of Excellence in Geometric Computing at Tel Aviv University, and by the Hermann Minkowski Minerva Center for
Geometry at Tel Aviv University. 相似文献
65.
The goal of this paper is to prove some general vector-valued perturbed equilibrium principles and some existence results of vector equilibrium points for bifunctions satisfying a new natural notion of lower semi-continuity. We obtain these results by going through a new concept of approximative equilibrium point. 相似文献
66.
Shutao Chen Xin He Henryk Hudzik Anna Kamińska 《Journal of Mathematical Analysis and Applications》2008,344(2):687-698
Criteria for strict monotonicity, upper (lower) locally uniform monotonicity and uniform monotonicity of Orlicz-Sobolev spaces with the Luxemburg norm are given. Some applications to best approximation are presented. 相似文献
67.
The notions of exhausters were introduced in (Demyanov, Exhauster of a positively homogeneous function, Optimization 45, 13–29
(1999)). These dual tools (upper and lower exhausters) can be employed to describe optimality conditions and to find directions
of steepest ascent and descent for a very wide range of nonsmooth functions. What is also important, exhausters enjoy a very
good calculus (in the form of equalities). In the present paper we review the constrained and unconstrained optimality conditions
in terms of exhausters, introduce necessary and sufficient conditions for the Lipschitzivity and Quasidifferentiability, and
also present some new results on relationships between exhausters and other nonsmooth tools (such as the Clarke, Michel-Penot
and Fréchet subdifferentials). 相似文献
68.
Lower bounds for blow-up time in a nonlinear parabolic problem 总被引:1,自引:0,他引:1
L.E. Payne 《Journal of Mathematical Analysis and Applications》2009,354(1):394-1014
For a parabolic problem with a gradient nonlinearity which was introduced by Chipot and Weissler [M. Chipot, F.B. Weissler, Some blow up results for a nonlinear parabolic problem with a gradient term, SIAM J. Math. Anal. 20 (1989) 886-907] (see also [B. Kawohl, L.A. Peletier, Observations on blow up and dead cores for nonlinear parabolic equations, Math. Z. 202 (1989) 207-217]), the question of blow-up is investigated. Specifically, if the solution blows up, a lower bound for the time of blow-up is derived 相似文献
69.
Randomized approximation of Sobolev embeddings, III 总被引:1,自引:1,他引:0
We continue the study of randomized approximation of embeddings between Sobolev spaces on the basis of function values. The source space is a Sobolev space with nonnegative smoothness order; the target space has negative smoothness order. The optimal order of approximation (in some cases only up to logarithmic factors) is determined. Extensions to Besov and Bessel potential spaces are given and a problem recently posed by Novak and Woźniakowski is partially solved. The results are applied to the complexity analysis of weak solution of elliptic PDE. 相似文献
70.
We present a constructive proof for the well-known Ky Fan’s coincidence theorem through a simplicial algorithm. In a finite
number of steps the algorithm generates a simplex containing an approximate coincidence point. In the limit, when the mesh
size converges to zero, the sequence of approximations converges to a coincidence point.
This research was carried out while the second author was visiting the CentER for Economic Research, Tilburg University. He
would like to thank both CentER and the Netherlands Organization for Scientific Research (NWO) for their financial support. 相似文献