Riesz Exponential Families on Symmetric Cones

Let E be a simple Euclidean Jordan algebra of rank r and let be its symmetric cone. Given a Jordan frame on E, the generalized power _s (– ^–1) defined on – is the Laplace transform of some positive measure R _s on E if and only if s is in a given subset of R ^r . The aim of this paper is to study the natural exponential families (NEFs) F(R _s ) associated to the measures R _s . We give a condition on s so that R _s generates a NEF, we calculate the variance function of F(R _s ) and we show that a NEF F on E is invariant by the triangular group if and only if there exists s in such that either F=F(R _s ) or F is the image of F(R _s ) under the map x–x.     

Asymptotic Distribution of Estimated Affinity between Multiparameter Exponential Families

Let F ₁,...,F _J be the distributions of J independent multiparameter exponential families, and _J (F ₁,...,F _J ) denote the affinity between F ₁,...,F _J . We consider the problem of estimating _J on the basis of independent random samples from these distributions. Subject to some mild regularity conditions, we derive the asymptotic distribution of the maximum likelihood estimator of _J . Applications to hypothesis testing and discriminant analysis are discussed, and an example is provided.     

Admissibility of prediction intervals

Admissibility of prediction intervals is considered in a specified family. It is shown that the best invariant prediction interval is strongly admissible in a location family and in a scale family. Though the similar result has not been obtained for a location and scale family, the best invariant prediction interval for a normal distribution is shown to be weakly admissible.     

Classification of Riesz Exponential Families on a Symmetric Cone by Invariance Properties

Letac⁽⁵⁾ has characterized the Wishart natural exponential families (NEFs) on the symmetric cone of a Jordan algebra E by invariance under a group G of automorphisms of E preserving . Hassairi and Lajmi⁽⁴⁾ have introduced the so called Riesz NEF's as an extension of the Wishart NEF's and they have characterized them by invariance under the triangular group T. Pursuing these classifications, we construct a class of subgroups of G containing the triangular group T and we use them to classify the Riesz NEFs on and therefore to characterize each class by an invariance property.     

Uniform Growth in Groups of Exponential Growth

This is an exposition of examples and classes of finitely-generated groups which have uniform exponential growth. The main examples are non-Abelian free groups, semi-direct products of free Abelian groups with automorphisms having an eigenvalue of modulus distinct from 1, and Golod–Shafarevich infinite finitely-generated p-groups. The classes include groups which virtually have non-Abelian free quotients, nonelementary hyperbolic groups, appropriate free products with amalgamation, HNN-extensions and one-relator groups, as well as soluble groups of exponential growth. Several open problems are formulated.     

Complete classes of tests for regularly varying distributions

This paper establishes essentially complete class theorems and gives conditions for admissibility of tests for parametric families of distributions having some kinds of regular variation properties. A complete treatment of topologically contiguous one-dimensional bounded and unbounded hypotheses is given. Examples of applications to well known families of distributions are presented.     

齐次Neumann边界条件下反应扩散方程的指数吸引子

利用构造挤压性的方法,讨论了齐次Neumann边界条件下反应扩散方程u_t-△u+λu=f(u)+β在H_(0¹)(Ω)中的指数吸引子的存在性.     

Exponential trichotomy and p-admissibility for evolution families on the real line

The aim of this paper is to obtain necessary and sufficient conditions for uniform exponential trichotomy of evolution families on the real line. We prove that if p ∈ (1,∞) and the pair (C_b(R,X),C_c(R,X)) is uniformly p-admissible for an evolution family ={U(t,s)}_t≥_s then is uniformly exponentially trichotomic. After that we analyze when the uniform p-admissibility of the pair (C_b(R, X), C_c(R, X)) becomes a necessary condition for uniform exponential trichotomy. As applications of these results we study the uniform exponential dichotomy of evolution families. We obtain that in certain conditions, the admissibility of the pair (C_b(R,X),L^p(R,X)) for an evolution family ={U(t,s)}_t≥_s is equivalent with its uniform exponential dichotomy.     

Entropy Production and Admissibility of Shocks

In shock wave theory there are two considerations in selecting the physically relevant shock waves.There is the admissibility criterion for the well-posedness of hyperbolic conservation laws.Another consideraztion concerns the entropy production across the shochs.The latter is natural from the physical point of view,but is not sufficient in its straightforward formulation,if the system is not genuinely nonlinear.In this paper we propose the principles of increasing entropy production and that of the superposition of shocks.These principles arc shown to be equivalent to the admissibility criterion.     

完备一致空间的非标准特征

In This paper, we prove that the uniform space (X, ψ) is complete if and only if for every remote point p in *X, there exists a pseudo-metric d in the lattice set of ψ and a positive number r such that d(p, q) ≥ r for each q ∈ X.     

指数样本中多个异常值的Unmasking检验

指数样本中多个异常值的非一致性检验因受masking或swamping效应的影响而变得十分的困难和复杂，解决这一问题的关键在于K值的确定，传统的方法是无能为力的．本文基于变量选择的AIC准则的思想提出了异常值检验的一种新方法，它具有不预先指定k，计算简单且通过达到极大化MAIC就能达到确定k和消除检验中的masking或swamping的优点．还给出了易计算检验显著水平的统计量和公式．最后，通过实例的验证标明本文方法的有效性．     

Admissibility and nonuniform polynomial dichotomies

For a general one-sided nonautonomous dynamics defined by a sequence of linear operators, we consider the notion of a polynomial dichotomy with respect to a sequence of norms and we characterize it completely in terms of the admissibility of bounded solutions. As a nontrivial application, we establish the robustness of the notion of a nonuniform polynomial dichotomy.     

On Uniform Exponential Stability of Exponentially Bounded Evolution Families

A result of Barbashin ([1], [15]) states that an exponentially bounded evolution family defined on a Banach space and satisfying some measurability conditions is uniformly exponentially stable if and only if for some 1 ≤ p < ∞, we have that:

飞机辅助动力装置引气特性计算方法

作为飞机环控系统与主发动机起动的气源,以目前广泛应用的带负载压气机结构APU(Auxiliary Power Unit)为研究对象,进行引气特性计算模型与计算方法研究。首先介绍了APU结构与引气工作特点,然后分析了建模时喘振控制阀SCV(Surge Control Valve)控制方法与APU共同工作机理,最后采用部件法建立了该类型APU引气计算数学模型。以某型APU为对象进行数值仿真并与实际试车数据比较,计算误差小于3%,表明所采用的建模方法是正确的,所建立的模型能够满足工程需求。      

A Classification of Reproducible Natural Exponential Families in the Broad Sense

Let be a positive Radon measure on having a Laplace transform L and F=F() be a natural exponential family (NEF) generated by . A positive Radon measure with >0 and its associated NEF F =F( ) are called the th convolution powers of and F, respectively, if . Let f _, (F) be the image of an NEF F under the affine transformation f _, :xx+. If for a given NEF F, there exists a triple (,,) in such that f _, (F)=F , we call F a reproducible NEF in the broad sense. In other words, an NEF F is reproducible in the broad sense if a convolution power of F equals an affine transformation of F. Clearly, for =1, F is reproducible in the broad sense if there exists an affinity under which F is invariant. In this paper we obtain a complete classification of the class of reproducible NEF's in the broad sense. We show that this class is composed of infinitely divisible NEF's and that it contains the class of NEF's having exponential and power variance functions as well as NEF's constituting discrete versions of the latter NEF's. We also provide a characterization of the reproducible NEF's in the broad sense in terms of their associated exponential dispersion models.     

A new version of a theorem of Minh–Räbiger–Schnaubelt regarding nonautonomous evolution equations

We develop a new version of a known theorem obtained by Van Minh, Räbiger, Schnaubelt in [N. Van Minh, F. Räbiger and R. Schnaubelt, Exponential stability, exponential expansiveness and exponential dichotomy of evolution equations on the half line, Integral Equ. Oper. Theory 32 (1998) pp. 332–353]. We rely completely on the classical ‘test functions’ method designed by Perron in 1930. The advantage of such a version is that is more readable since the classical method of Perron have been known for decades and that we do not involve a sophisticated mathematical machinery. Our approach is in contrast with the general philosophy of ‘autonomization’ the nonautonomous system, since we do not require to attach the evolution semigroup. Also we point out a discrete-time version of our approach extending some known results given by Li and Henry.     

A Novel Simulation Method for Binary Discrete Exponential Families,With Application to Social Networks

Stochastic models for finite binary vectors are widely used in sociology, with examples ranging from social influence models on dichotomous behaviors or attitudes to models for random graphs. Exact sampling for such models is difficult in the presence of dependence, leading to the use of Markov chain Monte Carlo (MCMC) as an approximation technique. While often effective, MCMC methods have variable execution time, and the quality of the resulting draws can be difficult to assess. Here, we present a novel alternative method for approximate sampling from binary discrete exponential families having fixed execution time and well-defined quality guarantees. We demonstrate the use of this sampling procedure in the context of random graph generation, with an application to the simulation of a large-scale social network using both geographical covariates and dyadic dependence mechanisms.     

A new proof of admissibility of tests in the multivariate analysis of variance

A new proof of admissibility of tests in MANOVA is given using Stein's theorem [7]. The convexity condition of Stein's theorem is proved directly by means of majorization rather than by the supporting hyperplane approach. This makes the geometrical meaning of the admissibility result clearer.     

非自治随机FitzHugh-Nagumo系统的随机一致指数吸引子

本文首先给出了非自治随机动力系统的随机一致指数吸引子的概念及其存在性判据,其次证明了Rn上的带加法噪声和拟周期外力的FitzHugh-Nagumo系统的随机一致指数吸引子的存在性.