导体平板的散射矩阵

利用物理光学法推导出在双站情况下，平面波以任意角度入射时，导体平板的散射矩阵公式。通过该公式分析在特殊角度入射情况下散射场的雷达散射截面（ＲＣＳ），并与文献解进行比较，验证了它的正确性。该公式结构清晰，计算简便，有利于进一步分析散射场的特性。     

计算轴盘系统临界转速的新方法

本文把随轴一起振动盘的惯性力看成是作用在轴上的外力，对有任意广盘的轴盘系统，采用Laplace变换导出了临界固有频率方程的解析式     

A Nonatomic‐Game Approach to Dynamic Pricing under Competition

We study a revenue management problem involving competing firms. We assume the presence of a continuum of infinitesimal firms where no individual firm has any discernable influence over the evolution of the overall market condition. Under this nonatomic‐game approach, the unanimous adoption of an equilibrium pricing policy by all firms will yield a market‐condition process that in turn will elicit the said policy as one of the best individual responses. For both deterministic‐ and stochastic‐demand cases, we show the existence of equilibrium pricing policies that exhibit well‐behaving monotone trends. Our computational study reveals many useful insights, including the fact that only a reasonable number of firms are needed for our approach to produce near‐rational pricing policies.     

Fixed‐Effects Dynamic Panel Models,a Factor Analytical Method

We consider the estimation of dynamic panel data models in the presence of incidental parameters in both dimensions: individual fixed‐effects and time fixed‐effects, as well as incidental parameters in the variances. We adopt the factor analytical approach by estimating the sample variance of individual effects rather than the effects themselves. In the presence of cross‐sectional heteroskedasticity, the factor method estimates the average of the cross‐sectional variances instead of the individual variances. The method thereby eliminates the incidental‐parameter problem in the means and in the variances over the cross‐sectional dimension. We further show that estimating the time effects and heteroskedasticities in the time dimension does not lead to the incidental‐parameter bias even when T and N are comparable. Moreover, efficient and robust estimation is obtained by jointly estimating heteroskedasticities.     

兵团固定资产投资与生产总值增长关系研究

生产总值和固定资产投资之间存在着动态均衡机制,经济增长为资本形成和投资增量的形成提供了物质基础,经济增长可以推动投资更快速度的增长;同时,经过相对较长时间的资本积累,固定资产投资对经济增长具有显著的促进作用。该文以固定资产投资和生产总值增长的关系为切入点,通过理论研究和实证分析,运用计量经济学联立方程模型,量化了兵团固定资产投资与生产总值增长之间的关系,并为相关部门的决策提出了建议。     

新建地方大学的定位与定位调整

北京联合大学办学定位与定位调整的实例说明:新建地方大学要做好学校的定位工作,应该做好影响定位的因素分析、强化市场意识和教育服务的观念、认识定位的基本规律、做好定位前期的调研和预测、注重定位的实施和落实等工作.     

Convergence of a fixed point algorithm

This note gives a condition which ensures convergence to an optimum of an algorithm suggested by Silvey, Titterington and Torsney (19 78) in the optimal design context.     

Maximum likelihood ridge displays

I illustrate likelihood methods for estimating the consequences of shrinkage along any ridge path as well as methods for picking a two-hyperparameter path of optimal curvature and the optimal point on that path. In addition to my published "classical" methods, I also illustrate both the empirical Bayes and the random coefficient maximum likelihood approaches. Traces of risks for known parameters and losses for simulated responses are followed by traces of estimates that can reveal the same general information.     

Adaptive and repeated cumulative meta‐analyses of safety data during a new drug development process

During a new drug development process, it is desirable to timely detect potential safety signals. For this purpose, repeated meta‐analyses may be performed sequentially on accumulating safety data. Moreover, if the amount of safety data from the originally planned program is not enough to ensure adequate power to test a specific hypothesis (e.g., the noninferiority hypothesis of an event of interest), the total sample size may be increased by adding new studies to the program. Without appropriate adjustment, it is well known that the type I error rate will be inflated because of repeated analyses and sample size adjustment. In this paper, we discuss potential issues associated with adaptive and repeated cumulative meta‐analyses of safety data conducted during a drug development process. We consider both frequentist and Bayesian approaches. A new drug development example is used to demonstrate the application of the methods. Copyright © 2015 John Wiley & Sons, Ltd.     

基于ANSYS的激光焊接温度场数值模拟与实验研究

为了探究钢铝2种金属材料的焊接性能,以B1500HS高强钢和6016铝合金为对象,基于ANSYS平台建立钢／铝激光平板搭接焊的三维有限元模型,进行焊接过程温度场数值模拟,采用热电偶同步测温方法测得焊接热循环曲线。将实测结果与数值模拟结果对比分析,表明吻合度较好。验证了模拟计算的准确性。