Choice of weights in FMA estimators under general parametric models

The choice of weights in frequentist model average estimators is an important but difficult problem. Liang et al. (2011) suggested a criterion for the choice of weight under a general parametric framework which is termed as the generalized OPT (GOPT) criterion in the present paper. However, no properties and applications of the criterion have been studied. This paper is devoted to the further investigation of the GOPT criterion. We show that how to use this criterion for comparison of some existing weights such as the smoothed AIC-based and BIC-based weights and for the choice between model averaging and model selection. Its connection to the Mallows and ordinary OPT criteria is built. The asymptotic optimality on the criterion in the case of non-random weights is also obtained. Finite sample performance of the GOPT criterion is assessed by simulations. Application to the analysis of two real data sets is presented as well.     

A SECRETARY PROBLEM ON FUZZY SETS

This paper deals with a secretary problem on fuzzy sets, which allows both the recall of applicants and the uncertainty of a current applicant receiving an offer of employment. A new decision criterion is given to select a satisfactory applicant. This result extends the works of M.C.K. Yang and M.H. Smith.     

Rademacher complexity in Neyman-Pearson classification

Neyman-Pearson（NP） criterion is one of the most important ways in hypothesis testing. It is also a criterion for classification. This paper addresses the problem of bounding the estimation error of NP classification, in terms of Rademacher averages. We investigate the behavior of the global and local Rademacher averages, and present new NP classification error bounds which are based on the localized averages, and indicate how the estimation error can be estimated without a priori knowledge of the class at hand.     

A BLOW-UP CRITERION FOR 3-D NON-RESISTIVE COMPRESSIBLE HEAT-CONDUCTIVE MAGNETOHYDRODYNAMIC EQUATIONS WITH INITIAL VACUUM

In this paper,we prove a blow-up criterion of strong solutions to the 3-D viscous and non-resistive magnetohydrodynamic equations for compressible heat-conducting flows with initial vacuum.This blow-up criterion depends only on the gradient of velocity and the temperature,which is similar to the one for compressible Navier-Stokes equations.     

ON COUPLING OF JUMP PROCESSES

This is a sequel to the paper [3] in which the marginality, regularity and orderpreservation for couplings of jump processes are studied. The main purpose of this note is to present a criterion and some practical suffcient conditions for the success of couplings and some criteria for the monotonicity of jump processes.     

Nonzero-sum games for continuous-time Markov chains with unbounded transition and average payoff rates

This paper attempts to study two-person nonzero-sum games for denumerable continuous-time Markov chains determined by transition rates,with an expected average criterion.The transition rates are allowed to be unbounded,and the payoff functions may be unbounded from above and from below.We give suitable conditions under which the existence of a Nash equilibrium is ensured.More precisely,using the socalled "vanishing discount" approach,a Nash equilibrium for the average criterion is obtained as a limit point of a sequence of equilibrium strategies for the discounted criterion as the discount factors tend to zero.Our results are illustrated with a birth-and-death game.     

Sums of primes and quadratic linear recurrence sequences

Let u be a sequence of positive integers which grows essentially as a geometric progression. We give a criterion on u in terms of its distribution modulo d, d = 1, 2,..., under which the set of positive integers expressible by the sum of a prime number and an element of u has a positive lower density. This criterion is then checked for some second order linear recurrence sequences. It follows, for instance, that the set of positive integers of the form p ＋ [（2 ＋ √3）n], where p is a prime number and n is a positive integer, has a positive lower density. This generalizes a recent result of Enoch Lee. In passing, we show that the periods of linear recurrence sequences of order m modulo a prime number p cannot be ＂too small＂ for most prime numbers p.     

ON THE GENERALIZED BIRTH AND DEATH PROCESSES(Ⅰ)——THE NUMERAL INTRODUCTION,THE FUNCTIONAL OF INTEGRAL TYPE AND THE DISTRIBUTIONS OF RUNS AND PASSAGE TIMES

This paper makes a painstaking discussion for the generalized birth and death processes, describes some properties of processes in fixed quantity: Such as the uniqueness criterion of processes and the distributions of runs and passage times of the generalized birth     

GENERALIZED SYMMETRIZED DIRICHLET DISTRIBUTIONS

In this paper we introduce a family of multivariate distributions,which consists of scale mixtures of symmetrized Dirichlet distributions,This family is a symmetrization of multivariate Liouville distributions and contains the well-known spherically symmetric distributions as a special case.The basic properties of this family such as stochastic representation,probability density functions,marginal and conditional distributions and components'independence are studied.A criterion of the invariance of statistics is also given.     

ON THE GENERALIZED BIRTH AND DEATH PROCESSES (Ⅰ)——THE NUMERAL INTRODUCTION,THE FUNCTIONAL OF INTEGRAL TYPE AND THE DISTRIBUTIONs OF RUNS AND PASSAGE TIMES

This paper makes a painstaking discussion for the generalized birth and death processes, describes some properties of processes in fixed quantity: Such as the uniqueness criterion of processes and the distributions of runs and passage times of the generalized birth and death processes which non—recurrent in (I); and stay time,     

复合型脆断的周向应力应变乘积判据

本文提出一个新的复合型脆断判据,即周向应力应变乘积判据,该判据与实验数据非常一致.     

关于交错级数的审敛准则的改进和推广

讨论了交错级数的敛散性,改进了[1]中关于交错级数新的审敛准则,并给出了交错级数另外新的审敛准则,并将这些审敛准则推广到更一般的形式.     

On a criterion of rationality for a series in orthogonal polynomials

We present a criterion of rationality for a function determined by its expansion in a series in orthogonal polynomials. This criterion can be regarded as an analog of the well-known Kronecker criterion of rationality for functions given by power series.     

New explicit critical criterion of Hopf–Hopf bifurcation in a general discrete time system

Hopf–Hopf bifurcation is one of typical codimension-two bifurcations, which requires some rigid bifurcation conditions and occurs only in high-dimension systems. In this paper, a new critical criterion of this bifurcation is presented for a general discrete time system. Unlike the corresponding classical critical criterion (or the bifurcation definition), the new criterion is composed of a series of algebraic conditions explicitly expressed by the coefficients of the characteristic polynomial, which does not depend on eigenvalue computations of Jacobian matrix. This characteristic gives the advantage of the proposed criterion which is more convenient and efficient for detecting the existence of this type of codimension-two bifurcation or exploring the parameter mechanism of the bifurcation than the corresponding classical criterion. The equivalence between the proposed criterion and the corresponding classical criterion is rigorously proved. The bifurcation design problem of a three-degree-of-freedom vibro-impact system is used as example to show the effectiveness of the proposed criterion.     

Algebraic A-hypergeometric functions

We formulate and prove a combinatorial criterion to decide if an A-hypergeometric system of differential equations has a full set of algebraic solutions or not. This criterion generalises the so-called interlacing criterion in the case of hypergeometric functions of one variable.     

The Condorcet criterion and committee selection

Recent studies have evaluated election procedures on their propensity to select committees that meet a Condorcet criterion. The Condorcet criterion has been defined to use majority agreement from voters' preferences to compare the selected committee to all other committees. This study uses a different definition of the Condorcet criterion as defined on committees. The focus of the new definition is on candidates. That is, we consider majority agreement on each candidate in the selected committee as compared to each candidate not in the selected committee.This new definition of the Condorcet criterion allows for the existence of majority cycles on candidates within the selected committee. However, no candidate in the non-selected group is able to defeat any candidate in the selected committee by majority rule. Of particular interest is the likelihood that a committee meeting this Condorcet criterion exists. Attention is also given to the likelihood that various simple voting procedures will select a committee meeting this Condorcet criterion when one does exist.     

反常积分敛散性的对数判别法

给出一个判别无穷限反常积分敛散性的对数判别法,并通过实例说明其应用．     

Optimality conditions in set optimization employing higher-order radial derivatives

There are two approaches of defining the solutions of a set-valued optimization problem:vector criterion and set criterion.This note is devoted to higher-order optimality conditions using both criteria of solutions for a constrained set-valued optimization problem in terms of higher-order radial derivatives.In the case of vector criterion,some optimality conditions are derived for isolated (weak) minimizers.With set criterion,necessary and sufficient optimality conditions are established for minimal solutions relative to lower set-order relation.     

含非线性扰动的变时滞中立系统时滞相关稳定性新条件

研究一类含非线性扰动和混合时变时滞的中立型系统时滞相关鲁棒稳定性问题.通过构造包含三重积分项的Lyapunov-Krasovskii的泛函,结合积分不等式和自由权矩阵技术,建立了基于线性矩阵不等式(LMI)形式的离散时滞和中立时滞均相关的稳定性新判据.判据扩大了系统稳定所允许的最大时滞上界范围,具有更低的保守性.利用MATLAB的LMI工具箱进行了数值仿真,仿真算例验证了所提出的稳定性判据的有效性.