Maximal Probability Inequalities for Stochastic Processes

Let X_a,b be nonnegative random variables with the property that X_a,b ≦ X_a,c + X_c.b for all 0≦ a < c < b ≦ T, where T > 0 is fixed. We define M_a,b = sup {X_a,c: a < c ≦ h} and establish bounds for P[M_a,b ≧ λ] in terms of given bounds for P[X_a,b ≧ λ], where λ runs through some interval (0, λ_o), 0 < λ_o ≦ ∞ fixed. These bounds explicitly involve a nonnegative function g(a, b) assumed to be quasi-superadditive with an index Q, i.e., g(a, c) + g(c, b) ≦ Qg(a, b) for all 0≦ a < c < b < T, where 1 ≦ Q < 2 is fixed. Maximal inequalities obtained in this way can be applied to stochastic processes exhibiting long-range dependence. Among others, these applications may include certain self-similar processes such as fractional Brownian motion, stochastic processes occurring in linear time series models, etc.     

随机过程增量不等式的推广

本文将推广在［３］中由Ｅ．Ｃｓａｋｉ及Ｍ．Ｃｓｏｒｇｏ所引入的关于随机过程不等式，并把它应用到某些随机过程中，从而得到这些随机过程的一些极限定理．     

Integro-Local Theorems in Boundary Crossing Problems for Compound Renewal Processes

We find sharp asymptotics for the probability that the moment when the trajectory of a compound renewal process crosses an arbitrary remote boundary lies in a prescribed small time interval. As a key step in our proof, we obtain limit theorems for the conditional distribution of jumps of the process when the endpoint of the trajectory of a compound renewal process is fixed.

     

Existence and Uniqueness of the Solution to a Degenerate Third Boundary Value Problem for a Multidimensional Parabolic Equation

Siberian Mathematical Journal - We study the well-posedness of a&nbsp;third boundary value problem for a&nbsp;multidimensional parabolic equation in the case when the coefficient of the...     

First Passage Densities and Boundary Crossing Probabilities for Diffusion Processes

We consider the boundary crossing problem for time-homogeneous diffusions and general curvilinear boundaries. Bounds are derived for the approximation error of the one-sided (upper) boundary crossing probability when replacing the original boundary by a different one. In doing so we establish the existence of the first-passage time density and provide an upper bound for this function. In the case of processes with diffusion interval equal to ℝ this is extended to a lower bound, as well as bounds for the first crossing time of a lower boundary. An extension to some time-inhomogeneous diffusions is given. These results are illustrated by numerical examples.      

A Two-Sided First-Exit Problem for a Compound Poisson Process with a Random Upper Boundary

We consider the first-exit time of a compound Poisson process from a region that is bounded from below by an increasing straight line, while its upper boundary has positive jumps of i.i.d. sizes at Poisson times and increases linearly between jumps. An integral equation for the corresponding Laplace-Stieltjes transforms is derived and solved. The case of exponential jumps is treated separately. The problem has applications in queueing and risk theory.AMS 2000 Mathematics Subject Classification: Primary 60G40; Secondary 62K25, 6OJ75     

Boundary Crossing for the Difference of Two Ordinary or Compound Poisson Processes

We consider the lower boundary crossing problem for the difference of two independent compound Poisson processes. This problem arises in the busy period analysis of single-server queueing models with work removals. The Laplace transform of the crossing time is derived as the unique solution of an integral equation and is shown to be given by a Neumann series. In the case of ±1 jumps, corresponding to queues with deterministic service times and work removals, we obtain explicit results and an approximation useful for numerical purposes. We also treat upper boundaries and two-sided stopping times, which allows to derive the conditional distribution of the maximum workload up to time t, given the busy period is longer than t.     

Boundary Crossing Probabilities of Jump Diffusion Processes to Time-Dependent Boundaries

Methodology and Computing in Applied Probability - The finite Markov chain imbedding technique has been used to compute the boundary crossing probabilities of one and higher-dimensional Brownian...     

Numerical Analysis of the Stochastic Moving Boundary Problem

We extend and generalize some recent results on complete convergence (cf. Hu, Moricz, and Taylor [14], Gut [11], Wang, Bhaskara Rao, and Yang [26], Kuczmaszewska and Szynal [17], and Sung [23]) for arrays of rowwise independent Banach space valued random elements. In the main result, no assumptions are made concerning the existence of expected values or absolute moments of the random elements and no assumptions are made concerning the geometry of the underlying Banach space. Some well-known results from the literature are obtained easily as corollaries. The corresponding convergence rates are also established     

Harnack Inequalities for Jump Processes

We consider a class of pure jump Markov processes in R ^d whose jump kernels are comparable to those of symmetric stable processes. We establish a Harnack inequality for nonnegative functions that are harmonic with respect to these processes. We also establish regularity for the solutions to certain integral equations.     

Uniformly More Powerful, Two-Sided Tests for Hypotheses about Linear Inequalities

Let Xhave a multivariate, p-dimensional normal distribution (p 2) with unknown mean and known, nonsingular covariance . Consider testing H ₀ : b _i 0, for some i = 1,..., k, and b _i 0, for some i = 1,..., k, versus H ₁ : b _i < 0, for all i = 1,..., k, or b _i < 0, for all i = 1,..., k, where b ₁,..., b _k , k 2, are known vectors that define the hypotheses and suppose that for each i = 1,..., k there is an j {1,..., k} (j will depend on i) such that b _i b _j 0. For any 0 < < 1/2. We construct a test that has the same size as the likelihood ratio test (LRT) and is uniformly more powerful than the LRT. The proposed test is an intersection-union test. We apply the result to compare linear regression functions.     

Regularizations for Stochastic Linear Variational Inequalities

This paper applies the Moreau–Yosida regularization to a convex expected residual minimization (ERM) formulation for a class of stochastic linear variational inequalities. To have the convexity of the corresponding sample average approximation (SAA) problem, we adopt the Tikhonov regularization. We show that any cluster point of minimizers of the Tikhonov regularization for the SAA problem is a minimizer of the ERM formulation with probability one as the sample size goes to infinity and the Tikhonov regularization parameter goes to zero. Moreover, we prove that the minimizer is the least \(l_2\) -norm solution of the ERM formulation. We also prove the semismoothness of the gradient of the Moreau–Yosida and Tikhonov regularizations for the SAA problem.     

Inequalities for Stationary Poisson Cuboid Processes

A cuboid is a rectangular parallelepipedon. By the notion “stationary Poisson cuboid process” we understand a stationary Poisson hyperplane process which divides the Euclidean space ?^d into cuboids. It is equivalent to speak of a stationary Poisson cuboid tessellation. The distributions of volume and total edge length of the typical cuboid and the origin-cuboid of a stationary Poisson cuboid process are considered. It is shown that these distributions become minimal, in the sense of a specific order relation, in the case of quasi-isotropy. A possible connection to a more general problem, treated in [6], is also discussed.     

Eigenvalue Problem of Doubly Stochastic Hamiltonian Systems with Boundary Conditions

In this paper, we investigate the eigenvalue problem of forward-backward doubly stochastic dii~erential equations with boundary value conditions. We show that this problem can be represented as an eigenvalue problem of a bounded continuous compact operator. Hence using the famous Hilbert-Schmidt spectrum theory, we can characterize the eigenvalues exactly.     

连续铸钢中的一类周期自由边界问题

本文讨论了连续铸钢中的一类周期自由边界问题,证明了周期古典解的存在性,唯一性和稳定性。     

Nash Inequalities for Markov Processes in Dimension One

In this paper, we give characterizations of Nash inequalities for birth-death process and diffusion process on the line. As a by-product, we prove that for these processes, transience implies that the semigroups P(t) decay as ∥P(t)∥_1→∞≥Ct ₋₁. Sufficient conditions for general Markov chains are also obtained. Received November 29, 2000, Revised February 21, 2001, Accepted March 16, 2001     

一维Markov过程的Nash不等式

本文得到了生灭过程和一维扩散过程满足Nash不等式的判别准则,并证明 了对此二类过程,非常返性蕴含相应半群如下收敛速度||P(t)||1→∞≤Ct-1.同时也给 出一般马氏链满足Nash不等式的充分条件.     

混合型随机微分方程的传输不等式

该文探讨一类由Wiener过程和Hurst参数1/2＜H＜1分数布朗运动驱动的混合型随机微分方程.通过使用一些变换技巧和逼近方法,这类方程的强解在d2度量和一致度量d∞下的二次传输不等式被建立.