Public housing into private assets: Wealth creation in urban China

State socialist economies provided public housing to urban citizens at nominal cost, while allocating larger and better quality apartments to individuals in elite occupations. In transitions to a market economy, ownership is typically transferred to existing occupants at deeply discounted prices, making home equity the largest component of household wealth. Housing privatization is therefore a potentially important avenue for the conversion of bureaucratic privilege into private wealth. We estimate the resulting inequalities with data from successive waves of a Chinese national income survey that details household assets and participation in housing programs. Access to privatization programs was relatively equal across urban residents in state sector occupations. Elite occupations had substantially greater wealth in the form of home equity shortly after privatization, due primarily to their prior allocations of newer and higher quality apartments. The resulting gaps in private wealth were nonetheless small by the standards of established market economies, and despite the inherent biases in the process, housing privatization distributed home equity widely across those who were resident in public housing immediately prior to privatization.     

基于NAT的中小型企业网络规划与设计

NAT是将私网地址转换成公网地址的技术,主要用于实现私有网络访问公共网络的功能.这种通过用较少的公网IP地址代替较多的私网IP地址的方式,将有助于减缓因IPv4地址不足造成的地址匮乏.文章论述了NAT技术的工作原理,把NAT技术应用于中小型企业网中进行网络的规划与设计,以实现整个网络的通信.     

一种音频样例重复检测方法的研究

提出了一种基于分段的音频样例重复检测方法,通过设置矩阵来表示样例间的相似度信息和匹配位置信息,计算样例间的匹配程度,记录检索结果.结果表明,该方法可以根据用户设置的重复阈值快速准确地找出重复样例,能提高检索系统的利用率和检出率.     

达里厄垂直轴风力机叶片螺旋变异优化研究

针对传统达里厄( Darrieus)直叶片垂直轴风力机在运行过程中出现叶片动转矩周期波动性大,动转矩系数曲线 震荡剧烈,造成对风轮旋转主轴的强烈冲击及风力机功率输出不稳定等问题,文章提出对Darrieus垂直轴风力机传统直 叶片进行螺旋扭曲变异设计,以改善风力机叶片的动转矩输出性能。结合SolidWorks和MATLAB完成风力机模型的三 维参数化建模,在流体仿真软件FLUENT中完成模型的数值模拟仿真计算。通过螺旋扭曲角的单因素试验验证了变异 设计叶片输出的动转矩性能周期波动性降低,平均动转矩得到提高,并确定螺旋扭曲角的优化区间。文章构建了风力机 系统模型建立与仿真体系,采取螺旋扭曲变异设计,改善了风力机叶片输出的动转矩性能,初步确定合理的螺旋扭曲角 分布范围为：70°~ ll0°。     

双螺杆泵Ω形对称型螺杆流场数值分析

由于螺杆泵几何结构及流体流动状态较为复杂,其压力分布和速度等特性很难用数学解析法来分析计算。本文利用参数化设计模块建立双螺杆泵Q形对称型螺杆三维模型,构建双螺杆流道的流场分析模型,运用有限元分析方法得出了双螺杆泵流道内压力场和速度场分布规律。结果表明：流体在流道中的流速分布具有规律性,整个流道的流场速度高低交替变化,在螺杆与衬套间隙处的流动为层流,螺旋面接触区内的流动为复杂的湍流,离螺杆啮合区近的螺旋槽内易发生涡流。本研究结果对于了解双螺杆泵螺杆工况下的性能情况具有重要的参考价值。     

基于CAN总线的隧道通风监测系统设计

为了实现隧道通风监测系统的高安全可靠性、远距离信息传输、多节点网络监测等要求,提出了基于CAN总线 技术的隧道通风监控系统。设计了基于CAN总线技术的控制系统硬件结构,介绍了烟雾和温度检测原理;设计了基于 CAN总线的通风系统监测节点;设计了工控机与CAN总线通信接口适配卡;设计了系统主程序、事件检查和处理子程序 的流程图。应用结果表明该系统具有传输距离远、监测网络节点多等特点,大大提高了系统的实时性和可靠性。     

Generalized empirical likelihood inference in partial linear regression model for longitudinal data

In this paper, empirical likelihood inference for longitudinal data within the framework of partial linear regression models are investigated. The proposed procedures take into consideration the correlation within groups without involving direct estimation of nuisance parameters in the correlation matrix. The empirical likelihood method is used to estimate the regression coefficients and the baseline function, and to construct confidence intervals. A nonparametric version of Wilk's theorem for the limiting distribution of the empirical likelihood ratio is derived. Compared with methods based on normal approximations, the empirical likelihood does not require consistent estimators for the asymptotic variance and bias. The finite sample behaviour of the proposed method is evaluated with simulation and illustrated with an AIDS clinical trial data set.     

东西相遇：中德双校园学习差异性比较分析——基于Z大学中德合作2＋3项目学生的访谈

在对Z大学中德合作2＋3项目留德学生访谈的基础上，以差异性分析为视角，从教学组织、专业学习和校园生活三个纬度，分析了项目学生对两校园学习的差异性体验，并从文化价值、教育体制、教育投入方面探究其原因，提出了强化国际合作、提升师资能力水平、加大工程实训领域投入等对策。     

Online coupon consumption problem

Nowadays, it is popular that the dealer makes profits by selling a kind of discount coupons, which can be used as money to purchase commodities with total cost less than or equal to the face value of the coupon. We can purchase a coupon at a price of 0<s≤1 times its face value and the number of potential purchasable coupons is a given integer l. The customer has the option to buy the goods by cash completely or by a discount coupon. However, each piece of goods can only use one coupon and the coupon used must have enough balance for the goods. The objective is to minimize the total cost for purchasing all the goods. In this paper, we reduce the problem to a special bin packing model. We consider the online problems for all 0<s≤1 and 1≤l≤∞. We present optimal online algorithms for all 0<s≤1 when l=∞ and l=1. For 2≤l<∞, we give both a lower bound and an algorithm, and show the algorithm is optimal for l=2. A preliminary version of this paper appeared in the proceedings of the 1st International Symposium on Combinatorics, Algorithms, Probabilistic and Experimental Methodologies, Lecture Notes in Computer Science. Y. Jiang supported by Natural Science Foundation of Zhejiang Province (Y605316). Z. Tan supported by Natural Science Foundation of China (10671177, 60021201).