共查询到20条相似文献,搜索用时 15 毫秒
1.
We obtain complete asymptotic expansions for the distribution of the crossing number of a strip in n steps by sample paths of a random walk defined on a finite Markov chain. We assume that the Cramér condition holds for the distribution of jumps and the width of the strip grows with n. The method consists in finding factorization representations of the moment generating functions of the distributions under study, isolating the main terms in the asymptotics of the representations, and inverting those main terms by the modified saddle-point method. 相似文献
2.
V. A. Gasanenko 《Ukrainian Mathematical Journal》1997,49(7):1023-1029
We give various representations of asymptotics for the probability for a Wiener process to reside within a curvilinear strip during extended time intervals. 相似文献
3.
The complete asymptotic expansions are obtained for the distribution of the crossing number of a strip in n steps by sample paths of an integer-valued random walk with zero mean. We suppose that the Cramer condition holds for the distribution of jumps and the width of strip increases together with n; the results are proven under various conditions on the width growth rate. The method is based on the Wiener–Hopf factorization; it consists in finding representations of the moment generating functions of the distributions under study, the distinguishing of the main terms of the asymptotics of these representations, and the subsequent inversion of the main terms by the modified saddle-point method. 相似文献
4.
V. I. Lotov 《Siberian Mathematical Journal》2010,51(1):119-127
We find factorization representations for the moment generating function of the joint distribution of the sojourn time of
a random walk in a strip and half-line in finitely many steps and of the location at the last time moment. 相似文献
5.
V. I. Lotov 《Siberian Mathematical Journal》2013,54(2):265-270
We find asymptotic representations for the distribution of the crossing number of an expanding strip by sample paths of a random walk in the case when the crossing number is finite with probability 1. The results are obtained under various restrictions on the rate of decrease at infinity for the distribution tails. 相似文献
6.
7.
V. I. Lotov 《Siberian Mathematical Journal》2010,51(4):621-638
We obtain asymptotic representations for the triple transforms of the joint distribution of the sojourn time of a random walk
in a strip (as well as in a half-plane) in n steps and of the location at time n under the condition of unboundedly moving-off boundaries of the sets. The Cramér type conditions are imposed on the distribution
of jumps. 相似文献
8.
The contribution presents a heuristic for the three-dimensional strip packing problem (3D-SPP) with rectangular pieces (boxes). The considered 3D-SPP can be formulated as follows: for a given set of boxes and a given longitudinal open container, determine an arrangement of all boxes within the container so that the required container length is minimized. 相似文献
9.
Anna Maria Mantero Tadeusz Pytlik Ryszard Szwarc Anna Zappa 《Annali di Matematica Pura ed Applicata》1993,165(1):23-28
Summary The spherical principal series of a non-commutative free group may be analytically continued to yield a series of uniformly bounded representations, much as the spherical representations (in1/2) + it of SL (2,R) may be analytically continued in the strip 0 < Rez < 1. This series of uniformly bounded representations was constructed and studied by A. M.Mantero and A.Zappa. Independently T.Pytlik and R.Szwarc introduced and studied representations of the free group which contain a series of subrepresentations indexed by spherical functions. Both series consist of irreducible representations and include the spherical complementary series. The aim of this paper is to prove that the non-unitary uniformly bounded representations of the two series are also equivalent. 相似文献
10.
Findings from physics education research strongly point to the critical need for teachers’ use of multiple representations in their instructional practices such as pictures, diagrams, written explanations, and mathematical expressions to enhance students' problem‐solving ability. In this study, we explored use of problem‐solving tasks for generating multiple representations as a scaffolding strategy in a high school modeling physics class. Through problem‐solving cognitive interviews with students, we investigated how a group of students responded to the tasks and how their use of such strategies affected their problem‐solving performance and use of representations as compared to students who did not receive explicit, scaffolded guidance to generate representations in solving similar problems. Aggregated data on students' problem‐solving performance and use of representations were collected from a set of 14 mechanics problems and triangulated with cognitive interviews. A higher percentage of students from the scaffolding group constructed visual representations in their problem‐solving solutions, while their use of other representations and problem‐solving performance did not differ with that of the comparison group. In addition, interviews revealed that students did not think that writing down physics concepts was necessary despite being encouraged to do so as a support strategy. 相似文献
11.
In a rather general setting of Itô-Lévy processes we study a class of transforms (Fourier for example) of the state variable of a process which are holomorphic in some disc around time zero in the complex plane. We show that such transforms are related to a system of analytic vectors for the generator of the process, and we state conditions which allow for holomorphic extension of these transforms into a strip which contains the positive real axis. Based on these extensions we develop a functional series expansion of these transforms in terms of the constituents of the generator. As application, we show that for multi-dimensional affine Itô-Lévy processes with state dependent jump part the Fourier transform is holomorphic in a time strip under some stationarity conditions, and give log-affine series representations for the transform. 相似文献
12.
A. I. Kolosov 《Mathematical Notes》1971,9(1):45-48
An investigation of a boundary-value problem on a half-line for a nonlinear ordinary second order differential equation whose free term has a discontinuity in a strip. A method is proposed for the transformation of the boundary-value problem into an integral equation with a discontinuous operator. Some results have recently been obtained concerning the existence, the comparison, and integral representations of solutions of this integral equation.Translated from Matematicheskie Zematki, Vol. 9, No. 1, pp. 77–82, January, 1971. 相似文献
13.
The two-dimensional cutting stock problem revisited 总被引:1,自引:0,他引:1
In the strip packing problem (a standard version of the two-dimensional cutting stock problem), the goal is to pack a given set of rectangles into a vertical strip of unit width so as to minimize the total height of the strip needed. The k-stage Guillotine packings form a particularly simple and attractive family of feasible solutions for strip packing. We present a complete analysis of the quality of k-stage Guillotine strip packings versus globally optimal packings: k=2 stages cannot guarantee any bounded asymptotic performance ratio. k=3 stages lead to asymptotic performance ratios arbitrarily close to 1.69103; this bound is tight. Finally, k=4 stages yield asymptotic performance ratios arbitrarily close to 1.Steve Seiden died in a tragic accident on June 11, 2002. This paper resulted from a number of email discussions between the authors in spring 2002. 相似文献
14.
In this paper, we give three kinds of Almansi representations for super-polyharmonic functions. As applications of these representations, we investigate two kinds of boundary value problems in superspace and construct solutions to the super-Poisson equation and the inhomogeneous super-polyharmonic equation. 相似文献
15.
16.
We consider the impedance boundary-value problem for the Helmholtz equation originated by the problem of wave diffraction by an infinite strip with imperfect conductivity. The two possible different situations of real and complex wave numbers are considered. Bessel potential spaces are used to deal with the problem, and the identification of corresponding operators of single and double layer potentials allow a reformulation of the problem into a system of integral equations. The well-posedness of the problem is obtained for a set of impedance parameters (and wave numbers), after the incorporation of some compatibility conditions on the data. At the end, an improvement of the regularity of the solution is derived for the same set of parameters previously considered. 相似文献
17.
O. M. Fomenko 《Journal of Mathematical Sciences》1988,43(4):2608-2613
Exact formulas are derived for the number of the representations of positive integers by certain positive ternary quadratic forms, belonging to multiclass genera. The Fourier coefficients of the corresponding cusp forms (on the basis of the known results of Waldspurger and Tunnell) are expressed in terms of the values of the Hasse-Weil L-functions of certain elliptic curves at the center of the critical strip.Translated from Zapiski Nauchnykh Seminarov Leningradskogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova AN SSSR, Vol. 154, pp. 154–162, 1986. 相似文献
18.
We develop a new approach to a posteriori error estimation for Galerkin finite element approximations of symmetric and nonsymmetric elliptic eigenvalue problems. The idea is to embed the eigenvalue approximation into the general framework of Galerkin methods for nonlinear variational equations. In this context residual-based a posteriori error representations are available with explicitly given remainder terms. The careful evaluation of these error representations for the concrete situation of an eigenvalue problem results in a posteriori error estimates for the approximations of eigenvalues as well as eigenfunctions. These suggest local error indicators that are used in the mesh refinement process. 相似文献
19.
Belinda B. King 《Proceedings of the American Mathematical Society》2000,128(5):1339-1346
In this paper we present results on existence and regularity of integral representations of feedback operators arising from parabolic control problems. The existence of such representations is important for the design of low order compensators and in the placement of sensors. This paper extends earlier results of J. A. Burns and B. B. King to problems with spatial dimensions. 相似文献
20.
本文利用特征值的泛函梯度方法,先给出Tu谱问题的Lenard算子对;尔后通过求解一个关键性的算子方程,得到Tu谱问题的演化方程族之换位表示。 相似文献