一般矩条件下随机变量的收敛性

本文在一般矩条件下研究了同分布的NA随机变量序列和独立同分布的随机变量序列的收敛性,得到了推广形式的Baum-Katz定理和强大数律,这些结果推广了已知的一些文献中相应的结果.

基于省际面板数据的全要素电力效率评价与分解模型

主要研究中国区域全要素电力效率及其驱动因素,探讨全要素电力效率与区域经济增长之间的相关关系,从而为节能减排政策的制定提供参考。应用数据包络分析理论建立了区域全要素电力效率评价模型;基于Malmquist生产率指数建立了全要素电力效率分解模型,以探讨全要素电力效率变化的驱动因素;建立动态面板数据模型,探讨全要素电力效率与经济增长之间的相关关系。以1995—2008年中国30个省、市、自治区的数据为样本,测算了区域全要素电力效率,结果表明经济发展快的区域全要素电力效率比较高,基于一般矩估计的动态面板数据模型的估计结果进一步证实了中国区域全要素电力效率与人均国内生产总值呈正相关关系,但与产业结构呈负相关关系;全要素电力效率分解模型的结果表明,除湖南外,其他区域的技术水平在提高。研究结果具有较高的政策建议价值,即技术进步和产业结构调整是提高中国区域全要素电力效率的重要措施。

剩余寿命分布类与剩余寿命函数特征的研究

阐述了递减方差剩余寿命(DVRL)分布与平衡分布的平均剩余寿命函数的密切联系;研究了递减方差剩余寿命(DVRL)分布类及递减百分位数剩余寿命分布类,并且给出了它们的一些特征;给出了以剩余寿命函数(RLF)的一般矩为基础的特征结果.

一种组合的脱机数字识别方法

提出了一种利用组合知识识别数字的方法。首先归一化的数字大小,自动阈值分割,细化处理,然后引入一般矩以及极半径不变矩并对它们加以修正,统计其值并依据各数字的长度及结构信息,提出基于一般2,3阶矩的平均,各二阶不变矩,以及长度等5个主要参量的数字识别方法,试验结果显示,该方法在识别率以及运算速度方面都比较令人满意。

Extensions of strongly π-regular general rings

The concept of the strongly π-regular general ring （with or without unity） is introduced and some extensions of strongly π-regular general rings are considered. Two equivalent characterizations on strongly π- regular general rings are provided. It is shown that I is strongly π-regular if and only if, for each x ∈I, x^n =x^n＋1y = zx^n＋1 for n ≥ 1 and y, z ∈ I if and only if every element of I is strongly π-regular. It is also proved that every upper triangular matrix general ring over a strongly π-regular general ring is strongly π-regular and the trivial extension of the strongly π-regular general ring is strongly clean.

Analytical solution of temperature in laminated beams subjected to general thermal boundary conditions

The temperature distribution in laminated beams underging thermal boundary conditions has been investigated.The thermal boundary conditions are general and include various combinations of prescribed heat fluxes and temperatures at the edges.An analytical solution of temperature for the laminated beam is present on the basis of the heat conduction theory in this paper.The proposed method is applicable to the beams with arbitrary thickness and layer numbers.Due to the complexity of the boundary conditions,the temperature field to be determined was considered from two sources.The first part was the temperature field from the complex temperature conditions at two edges of the laminated beam.The solution for the temperature of the first part was constructed to satisfy temperature boundary conditions at two edges.The second part was the temperature field from the upper and lower surface temperatures without taking account of the thermal conditions at two edges.In this part,the exact solution for the temperature was obtained based on the heat conduction theory.The convergence of the solution was examined by analyzing terms of Fourier series.The validity and feasibility of the proposed method was verified by comparing theoretical results with numerical results due to the equivalent single layer approach and the finite element method(FEM).The influences of surface temperatures,beam thicknesses,layer numbers and material properties with respects to the solution of the temperature field of the beam were investigated via a series of parametric studies.

Inter-Well Coupling and Resonant Tunneling Modes of Multiple Graphene Quantum Wells

We investigate the inter-well coupling of multiple graphene quantum well structures consisting of graphenesuperlattices with different periodic potentials.The general form of the eigenlevel equation for the bound states of thequantum well is expressed in terms of the transfer matrix elements.It is found that the electronic transmission exhibitsresonant tunneling peaks at the eigenlevels of the bound states and shifts to the higher energy with increasing the incidentangle.If there are N coupled quantum wells,the resonant modes have N-fold splitting.The peaks of resonant tunnelingcan be controlled by modulating the graphene barriers.

新凯恩斯菲利普斯曲线的弱识别检验和稳健估计

对基于GMM大样本统计量的检验和估计,弱识别会带来点估计不一致和置信区间规模不正确的问题。本文讨论了弱识别问题产生的原因、影响、检验和相关弱识别稳健统计量。用Cragg-Donald F统计量对NKPC重新进行了检验,发现的确存在弱识别问题,本文进而对NKPC的参数进行了弱识别稳健的估计,并且用CLR统计量构造了相应规模正确的置信区间。实证表明中国的通货膨胀具有明显的向前和向后行为,而向前行为从数量上来说要大于向后行为的影响,但是向后行为在数量上来说也是不可忽视的;子样本的检验表明通胀的向后行为有增强的趋势。

Systems of Matrix Equations over a Central Algebra

Let Ω be a finite dimensional central algebra with an involutorial anti-automorphism and chartΩ≠2.Two systems of matrix equations over Ω are consid-ered.Necessary and sufficient conditions for the existences of general solutions,andper(skew)selfconjugate solutions of the systems are given,respectively.