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101.
A. M. Chebotarev 《Mathematical Notes》1996,60(5):544-561
We prove that the Hudson-Parthasarathy equation corresponds, up to unitary equivalence, to the strong resolvent limit of Schrödinger Hamiltonians in Fock space and that the symmetric form of this equation corresponds to the weak limit of the Schrödinger Hamiltonians.Translated fromMatematicheskie Zametki, Vol. 60, No. 5, pp. 726–750, November, 1996. 相似文献
102.
初级产品生产行业有两大特点:一是其初级投资有较大的不可逆转性,二是其产品价格具有较大的随机性(不确定性)。这两点的同时存在,给进入和退出初级产品行业造成壁垒。 相似文献
103.
Erica L. Plambeck Bor-Ruey Fu Stephen M. Robinson Rajan Suri 《Mathematical Programming》1996,75(2):137-176
In this paper we propose a method for optimizing convex performance functions in stochastic systems. These functions can include
expected performance in static systems and steady-state performance in discrete-event dynamic systems; they may be nonsmooth.
The method is closely related to retrospective simulation optimization; it appears to overcome some limitations of stochastic
approximation, which is often applied to such problems. We explain the method and give computational results for two classes
of problems: tandem production lines with up to 50 machines, and stochastic PERT (Program Evaluation and Review Technique)
problems with up to 70 nodes and 110 arcs.
Sponsored by the National Science Foundation under grant number CCR-9109345, by the Air Force Systems Command, USAF, under
grant numbers F49620-93-1-0068 and F49620-95-1-0222, by the U.S. Army Research Office under grant number DAAL03-92-G-0408,
and by the U.S. Army Space and Strategic Defense Command under contract number DASG60-91-C-0144. The U.S. Government has certain
rights in this material, and is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding
any copyright notation thereon.
Sponsored by a Wisconsin/Hilldale Research Award, by the U.S. Army Space and Strategic Defense Command under contract number
DASG60-91-C-0144, and the Air Force Systems Command, USAF, under grant number F49620-93-1-0068.
Sponsored by the National Science Foundation under grant number DDM-9201813. 相似文献
104.
Klaus Ziegler 《Journal of multivariate analysis》1997,62(2):233-272
Functional central limit theorems for triangular arrays of rowwise independent stochastic processes are established by a method replacing tail probabilities by expectations throughout. The main tool is a maximal inequality based on a preliminary version proved by P. Gaenssler and Th. Schlumprecht. Its essential refinement used here is achieved by an additional inequality due to M. Ledoux and M. Talagrand. The entropy condition emerging in our theorems was introduced by K. S. Alexander, whose functional central limit theorem for so-calledmeasure-like processeswill be also regained. Applications concern, in particular, so-calledrandom measure processeswhich include function-indexed empirical processes and partial-sum processes (with random or fixed locations). In this context, we obtain generalizations of results due to K. S. Alexander, M. A. Arcones, P. Gaenssler, and K. Ziegler. Further examples include nonparametric regression and intensity estimation for spatial Poisson processes. 相似文献
105.
We use the topological tool of Nielsen fixed-point theory to study the controllability of perturbed linear control processes whose control space can be reduced to a finite-dimensional one. These methods produce a lower bound on the number of controls that achieve a given target. We concentrate particularly on the case where the perturbation has sublinear growth, and we exhibit examples of multiple controls of various types that are detected by the Nielsen theory method.This research was partly supported by the Research Grant Teoria del Controllo dei Sistemi Dinamici, Ministero della Pubblica Istruzione, Roma, Italy. 相似文献
106.
Y. Wardi 《Journal of Optimization Theory and Applications》1990,64(2):399-417
Stochastic algorithms for optimization problems, where function evaluations are done by Monte Carlo simulations, are presented. At each iteratex
i, they draw a predetermined numbern(i) of sample points from an underlying probability space; based on these sample points, they compute a feasible-descent direction, an Armijo stepsize, and the next iteratex
i+1. For an appropriate optimality function , corresponding to an optimality condition, it is shown that, ifn(i) , then (x
i) 0, whereJ is a set of integers whose upper density is zero. First, convergence is shown for a general algorithm prototype: then, a steepest-descent algorithm for unconstrained problems and a feasible-direction algorithm for problems with inequality constraints are developed. A numerical example is supplied. 相似文献
107.
Christian Maes 《Journal of statistical physics》1990,61(3-4):667-681
An anisotropic lattice gas dynamics is investigated for which particles on
d
jump to empty nearest neighbor sites with (fast) rate –2 in a specified direction and some particular configuration-dependent rates in the other directions. The model is translation and reflection invariant and is particle conserving. The space coordinate in the fast-rate direction is rescaled by –1. It follows that the density field converges in probability, as 0, to the corresponding solution of a nonlinear diffusion-type equation. The microscopic fluctuations about the deterministic macroscopic evolution are determined explicitly and it is found that the stationary fluctuations decay via a power law (1/r
d
) with the direction dependence of a quadrupole field. 相似文献
108.
Current and logarithm-current distributions on a three-dimensional random-bond percolation cubic network were studied at the percolation threshold by computer simulations. Predictions of a hierarchical model that combine fractal structure and randomness agree with our numerical simulations. In the thermodynamic limit the logarithm-current distribution exhibits ann(ln(i))i
1/3 dependence below some characteristic currenti
c. This distribution may scale with lni/lnL, but the data are insufficient to make this a definite conclusion. Due to the small range of lnL considered, a study of the moments does not reveal this behavior and a study of the distribution itself is required. 相似文献
109.
Costas Courcoubetis Panagiotis Konstantopoulos Jean Walrand Richard R. Weber 《Queueing Systems》1989,5(1-3):37-54
Consider a production system that consists ofm machines each of which can produce parts ofn types. When machinek is used, it produces a part of typei with probabilityp
ki
. Requests arrive for parts, one at a time. With probability
i
an arriving request is for a part of typei. The requests must be served without waiting. Thus, if a requested part is not available, it must be produced. We find necessary and sufficient conditions for the existence of a strategy (a choice of the machines to be used) which makes the inventory of parts stable and we provide such a strategy.Two variations of this model are also considered: the case of batch arrivals of requests, and that of a system where the requests can be queued. 相似文献
110.
In this paper, we identify a new class of stochastic linearconvex optimal control problems, whose solution can be obtained by solving appropriate equivalent deterministic optimal control problems. The term linear-convex is meant to imply that the dynamics is linear and the cost function is convex in the state variables, linear in the control variables, and separable. Moreover, some of the coefficients in the dynamics are allowed to be random and the expectations of the control variables are allowed to be constrained. For any stochastic linear-convex problem, the equivalent deterministic problem is obtained. Furthermore, it is shown that the optimal feedback policy of the stochastic problem is affine in its current state, where the affine transformation depends explicitly on the optimal solution of the equivalent deterministic problem in a simple way. The result is illustrated by its application to a simple stochastic inventory control problem.This research was supported in part by NSERC Grant A4617, by SSHRC Grant 410-83-0888, and by an INRIA Post-Doctoral Fellowship. 相似文献