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621.
622.
Summary This paper deals with the following problem, given a two parameter stochastic process, under what conditions is it possible to stop the process at any stopping line? It is shown that the class of stoppable processes is strictly larger than the class of two parameter integrators. Sufficient conditions for a weak martingale to be stoppable are derived and the stopped r.v. is represented as a one parameter optional dual projection.Work partially supported by a grant from the Research Authority at Bar-Ilan UniversityWork supported by the fund for promotion of research at the Technion 相似文献
623.
Some partial orderings of positively dependent exchangeable random variables are introduced. The interrelations among them, the inequalities which follow from them and two models which yield such partial orderings are then discussed. Particular examples include ordering multivariate normal, t, χ2, Cauchy, exponential, binomial, Poisson, gamma and Farlie-Gumbel-Morgenstern random vectors. Applications to genetic selection and choice of sampling procedures are given. 相似文献
624.
We model the working of a civil engineering firm concerned with land development as a three stage flexible flowshop with weak chain precedence constraints and where preemption is allowed. The scheduling objective is to minimize the total tardiness for all the projects. Since solving this problem optimally is very hard, we propose a number of heuristic scheduling procedures which are evaluated extensively on real-life data and artificial problem instances. 相似文献
625.
Moshe Dayan 《Surface science》1985,149(1):L33-L38
626.
627.
We present a simple derivation of classes of early-time solutions of the Smoluchowski equation in the presence of boundaries, simplifying and generalizing an analysis by van Kampen. 相似文献
628.
Moshe Rosenfeld 《Journal of Combinatorial Theory, Series B》1982,33(2):191-195
A triangle free graph which cannot be embedded in a unit sphere is constructed. The construction uses the powerful orthogonal representation of graphs due to Lovász, and exhibits a strong connection between embeddability and Ramsey numbers. We also show that for every ε > 0 there is a triangle free graph Gε that is not embeddable, thus settling Larman's conjecture. 相似文献
629.
For finite field extensions of the field of Henselian p-adic rational numbers necessary and sufficient conditions are given which state that the fields have isomorphic absolute Galois groups; it is thereby supposed that a p-th root of unity (a 4-th when p = 2) belongs to the fields. Also examples are discussed. 相似文献
630.
The conditions for obtaining stable dispersions of 10-μ droplets of monomer in an aqueous phase using steric and electrostatic stabilizers, were studied. The nature and concentration of the surfactant in the aqueous phase has an important effect on the size of the droplets and the stability of the dispersion during the polymerization reaction. The amount of polyvinylalcohol adsorbed on the interface was measured and the rate of desorption was shown to be very slow. It was also shown that sodium dodecyl sulfate, on the other hand, is more readily desorbed. These findings have an effect on the amount of the submicron emulsion particles formed during the polymerization process. 相似文献