On a generalized Eulerian distribution

The distribution with probability function p _k(n, , ) = A _{n, k}(, )/(+ )^[p], k = 0, 1, 2, ..., n, where the parameters and are positive real numbers, A _{n, k} (, ) is the generalized Eulerian number and ( + )^[n] = ( + )( + +1) ... ( + +n – 1), introduced and discussed by Janardan (1988, Ann. Inst. Statist. Math., 40, 439–450), is further studied. The probability generating function of the generalized Eulerian distribution is expressed by a generalized Eulerian polynomial which, when expanded suitably, provides the factorial moments in closed form in terms of non-central Stirling numbers. Further, it is shown that the generalized Eulerian distribution is unimodal and asymptotically normal.     

两个包含欧拉数的恒等式的等价性

基于n维多项式空间中基之间的线性变换，证明了两个包含欧拉数的恒等式是等价．     

两个包含欧拉数的恒等式的等价性(英文)

基于n维多项式空间中基之间的线性变换,证明了两个包含欧拉数的恒等式是等价.     

A context-free grammar for the e-positivity of the trivariate second-order Eulerian polynomials

Ma-Ma-Yeh made a beautiful observation that a transformation of the grammar of Dumont instantly leads to the γ-positivity of the Eulerian polynomials. We notice that the transformed grammar bears a striking resemblance to the grammar for 0-1-2 increasing trees also due to Dumont. The appearance of the factor of two fits perfectly in a grammatical labeling of 0-1-2 increasing plane trees. Furthermore, the grammatical calculus is instrumental to the computation of the generating functions. This approach can be adapted to study the e-positivity of the trivariate second-order Eulerian polynomials first introduced by Dumont in the contexts of ternary trees and Stirling permutations, and independently defined by Janson, in connection with the joint distribution of the numbers of ascents, descents and plateaux over Stirling permutations.     

On the Convergence of Series of Reciprocals of Primes Related to the Fermat Numbers

We examine densities of several sets connected with the Fermat numbers F_m=2^2m+1. In particular, we prove that the series of reciprocals of all prime divisors of Fermat numbers is convergent. We also show that the series of reciprocals of elite primes is convergent.     

广义de Bruijn有向图及其叠线图的支撑树与欧拉环游的计数

给出了一类特殊的广义deBruijn有向图的支撑树与欧环游的数目的简洁表示式，并得到了广义deBruijn有向叠线图的支撑树与欧拉环境数目的计算公式。     

On the Decay of Crossing Numbers of Sparse Graphs

Richter and Thomassen proved that every graph has an edge e such that the crossing number of is at least . Fox and Cs. Tóth proved that dense graphs have large sets of edges (proportional in the total number of edges) whose removal leaves a graph with crossing number proportional to the crossing number of the original graph; this result was later strenghthened by ?erný, Kyn?l, and G. Tóth. These results make our understanding of the decay of crossing numbers in dense graphs essentially complete. In this article we prove a similar result for large sparse graphs in which the number of edges is not artificially inflated by operations such as edge subdivisions. We also discuss the connection between the decay of crossing numbers and expected crossing numbers, a concept recently introduced by Mohar and Tamon.     

On the Distribution of Weakly Composite Numbers

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具有多个奇点的广义的Liénard系统不存在任何闭轨的条件

本文不同于一般的方法，利用辅助函数建立了具有多个奇点的广义的Ｌｉéｎａｒｄ系统（Ｅ）不存在任何闭轨的若干判别条件，关于（Ｅ）的经典的Ｂｅｎｄｉｘｓｏｎ判别法则和Ｐｏｉｎｃａｒé地形系法则是其特例．此外，给出了包括三次振动系统在内的例子．     

Applications of an Explicit Formula for the Generalized Euler Numbers

The authors establish an explicit formula for the generalized Euler NumbersE2n^（x）, and obtain some identities and congruences involving the higher＇order Euler numbers, Stirling numbers, the central factorial numbers and the values of the Riemann zeta-function.     

Bass Numbers of Local Cohomology Modules with Respect to an Ideal

Let be a commutative Noetherian local ring and let be an ideal of R. We give some inequalities between the Bass numbers of an R–module and those of its local cohomology modules with respect to . As an application of these inequalities, we recover results of Delfino-Marley and Kawasaki by showing that for a minimax R-module M and for any non-negative integer i, the Bass numbers of the ith local cohomology module are finite if one of the following holds:

On the number of rectangulations of a planar point set

We investigate the number of different ways in which a rectangle containing a set of n noncorectilinear points can be partitioned into smaller rectangles by n (nonintersecting) segments, such that every point lies on a segment. We show that when the relative order of the points forms a separable permutation, the number of rectangulations is exactly the (n+1)st Baxter number. We also show that no matter what the order of the points is, the number of guillotine rectangulations is always the nth Schröder number, and the total number of rectangulations is O(n²⁰/n⁴).     

On a generalization of Morisita's model for estimating the habitat preference

The Morisita's model for estimating the habitat preference by the ant lionsGenuroides japonicus is generalized by introducing, in addition to the environmental densitiesa andb, a repulsivity parameter . The probability function of the numberL _n of individuals choosing fine sand to settle when a total ofn ant lions are introduced is examined. A heuristic and the minimum chi-square methods for estimating the parametersa, b and are discussed.     

Fibonacci数列倒数的无穷和

利用初等方法以及取整函数的性质研究了Fibonacci数列三次倒数的求和问题,获得了该和式倒数取整后的确切值,也就是给出了一个包含Fibonacci数列有趣的恒等式.     

On the Asymptotic Behavior of the Bass Numbers of Modules

Let (R, 𝔪) be a Noetherian Gorenstein local ring and I be a principal ideal of R. In this article we show that the Bass numbers of the R-modules R/I ⁿ take constant values for large n.     

On the Average Distribution of Inversive Pseudorandom Numbers

The inversive congruential method is an attractive alternative to the classical linear congruential method for pseudorandom number generation. The authors have recently introduced a new method for obtaining nontrivial upper bounds on the multidimensional discrepancy of inversive congruential pseudorandom numbers in parts of the period. This method has also been used to study the multidimensional distribution of several other similar families of pseudorandom numbers. Here we apply this method to show that, “on average” over all initial values, much stronger results than those known for “individual” sequences can be obtained.     

Norm of an Integral Operator Related to the Harmonic Bergman Projection

The norm of the operator