CO-OFDM系统中基于线性预处理的新相位噪声抑制算法

针对相干光正交频分复用（coherent optical orthogonal frequency division multiplexing,CO-OFDM）系统中相位噪声引起的载波间干扰（inter-carrier interference,ICI）问题,提出了一种基于线性预处理的新判决反馈相位噪声抑制算法。该新算法改进了线性预处理部分,利用循环前缀与OFDM符号固有的相关性,在时域进行简单的线性组合运算,充分利用了OFDM符号中冗余信息。仿真分析表明,在激光器线宽为200 kHz且误码率（bit error rate, BER）为10－4时,与判决反馈相位噪声抑制算法和一次迭代的判决反馈相位噪声抑制算法相比,该新算法BER曲线的信噪比（signal to noise ratio,SNR）分别改善了3 dB和1 dB,有效地降低由ICI引起的错误平层。     

从“凯恩斯效应”到“阿米曲线”——政府规模与经济增长关系的非线性转向

政府规模与经济增长之间的关系问题是宏观经济研究中的核心问题之一.关于两者关系的传统研究往往以线性假定为基础,所以实证结果出现了巨大的差异.这种现象促使研究者从非线性角度重新审视政府规模与经济增长之间的关系.“巴罗法则”在内生增长框架内为政府规模与经济增长关系研究提供了一个标准的分析框架,揭示了两者之间的倒“U”关系.而“Armey曲线”不仅非常直观地表达了政府规模与经济增长之间的非线性关系,同时还指出这种非对称关系的非对称性质,具有很强的总结性和政策指导意义.     

Accuracy of approximate progressively censored reliability sampling plans for exponential models

Reliability sampling plans provide an efficient method to determine the acceptability of a product based upon the lifelengths of some test units. Usually, they depend on the producer and consumer’s quality requirements and do not admit closed form solutions. Acceptance sampling plans for one- and two-parameter exponential lifetime models, derived by approximating the operating characteristic curve, are presented in this paper. The accuracy of these approximate plans, which are explicitly expressible and valid for failure and progressive censoring, is assessed. The approximation proposed in the one-parameter case is found to be practically exact. Explicit lower and upper bounds on the smallest sample size are given in the two-parameter case. Some additional advantages are also pointed out.     

使用PC1D 5.9模拟高效单晶硅太阳能电池

介绍了使用PC1D 5.9软件模拟高效单晶硅太阳能电池的方法。通过建立太阳能电池的结构模型和参数模型,在模拟的电池测试环境下,仿真得到太阳能电池的电压-电流曲线和量子效率曲线,并根据太阳能电池的理论,计算填充因子和转换效率的值。     

Multivariate outliers and decompositions of mahalanobis distance

Two decompositions of the Mahalanobis distance are considered. These decompositions help to explain some reasons for the outlyingness of multivari- ate observations. They also provide a graphical tool for identifying outliers including those that have a large influence on the multiple correlation coefficient, Illustrative examples are given.     

Optimal design of complex experiments with qualitative factors of influence

A complex experiment with qualirarive factors influencing the outcome of the experiment can be seen as a general ANOVA setup. A design of such an experiment will be the assignment at which of the possible levels of the factors the actual experiment should be performed. In this paper optimal designs of such experiments will be characterized with respect to three different optimality criteria including the so called uniform optimality of a design. The possible applications of the main optimization result providing these characterizations can be used to more general experiments. The particular results on these generalizations will be indicated at the end of this paper.     

Sexual Frequency and the Stability of Marital and Cohabiting Unions

Prior research found that lower sexual frequency and satisfaction were associated with higher rates of divorce, but little research had examined the role of sexual activity in the dissolution of cohabiting unions. We drew upon social exchange theory to hypothesize why sexual frequency is more important in cohabitation: (a) cohabitors' lower costs of finding sexual alternatives, (b) cohabitors' lower barriers to ending the relationship in the form of union‐specific economic and noneconomic capital, and (c) cohabitors' higher expectations for sexual activity. Using the National Survey of Families and Households (N = 5,902), we examined the relationship between sexual frequency and union dissolution. Results indicated that low sexual frequency was associated with significantly higher rates of union dissolution among cohabitors than married couples.     

Contrasting the Gini and Zenga indices of economic inequality

The current financial turbulence in Europe inspires and perhaps requires researchers to rethink how to measure incomes, wealth, and other parameters of interest to policy-makers and others. The noticeable increase in disparities between less and more fortunate individuals suggests that measures based upon comparing the incomes of less fortunate with the mean of the entire population may not be adequate. The classical Gini and related indices of economic inequality, however, are based exactly on such comparisons. It is because of this reason that in this paper we explore and contrast the classical Gini index with a new Zenga index, the latter being based on comparisons of the means of less and more fortunate sub-populations, irrespectively of the threshold that might be used to delineate the two sub-populations. The empirical part of the paper is based on the 2001 wave of the European Community Household Panel data set provided by EuroStat. Even though sample sizes appear to be large, we supplement the estimated Gini and Zenga indices with measures of variability in the form of normal, t-bootstrap, and bootstrap bias-corrected and accelerated confidence intervals.     

基于单片机AT89C51的全自动变频恒压供水系统

介绍了一种新型的变频恒压供水系统.该系统根据供水管网的用水情况,调整水泵投入台数及转速,实行全自动恒压供水,达到高效节能的目的;其水泵用变频器软启动,对电网无冲击,能延长水泵的使用寿命.     

一种榫卯连接方钢管组装框架模型的荷载 位移曲线试验研究

提出一种榫卯连接方钢管组装框架结构。对两个方向的平面框架模型进行受力性能试验。介绍试验概况，给出框架模型的竖向荷载与挠度和水平荷载与水平侧移曲线，这些曲线介于刚节点框架和铰节点框架之间，属于半刚性节点框架的范畴。