基于复合信号的激光陀螺零偏误差补偿分析

作为一种集成了光学、电学和机械力学的复杂系统，激光陀螺可以精确地测量物体的角速率输出。为了满足惯性导航系统长时、高精度的测量要求，研究了激光陀螺内部不同类型的传感器与激光陀螺零偏误差之间的特性，在传统的基于温度的零偏误差补偿方法的基础上，引入了二频机抖激光陀螺内部温度传感器、光电二极管和粘在抖动机构上压电陶瓷的输出信息进行复合建模，利用非线性拟合能力强的支持向量机算法，针对不同类型信息与二频机抖激光陀螺零偏误差的相关性对模型进行优化。实验结果表明，该二频机抖激光陀螺零偏误差补偿模型的补偿精度高于传统的补偿方法。     

The effects of model parameter deviations on the variance of a linearly filtered time series

We consider a general linear filtering operation on an autoregressive moving average (ARMA) time series. The variance of the filter output, which is an important quantity in many applications, is not known with certainty because it depends on the true ARMA parameters. We derive an expression for the sensitivity (i.e., the partial derivative) of the output variance with respect to deviations in the model parameters. The results provide insight into the robustness of many common statistical methods that are based on linear filtering and also yield approximate confidence intervals for the output variance. We discuss applications to time series forecasting, statistical process control, and automatic feedback control of industrial processes. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

The building evacuation problem with shared information

In this article, the Building Evacuation Problem with Shared Information (BEPSI) is formulated as a mixed integer linear program, where the objective is to determine the set of routes along which to send evacuees (supply) from multiple locations throughout a building (sources) to the exits (sinks) such that the total time until all evacuees reach the exits is minimized. The formulation explicitly incorporates the constraints of shared information in providing online instructions to evacuees, ensuring that evacuees departing from an intermediate or source location at a mutual point in time receive common instructions. Arc travel time and capacity, as well as supply at the nodes, are permitted to vary with time and capacity is assumed to be recaptured over time. The BEPSI is shown to be NP‐hard. An exact technique based on Benders decomposition is proposed for its solution. Computational results from numerical experiments on a real‐world network representing a four‐story building are given. Results of experiments employing Benders cuts generated in solving a given problem instance as initial cuts in addressing an updated problem instance are also provided. © 2008 Wiley Periodicals, Inc. Naval Research Logistics, 2008     

两栖型指控车非线性横摇安全盆侵蚀研究

采用单自由度系统研究了两栖型指控车在规则波激励下的非线性横摇和倾覆,非线性横摇控制方程应用四阶龙格库塔法进行数值积分;以波浪扰动力矩的幅值和波浪的频率作为变量,研究了两栖型指控车的安全盆侵蚀问题。以波浪扰动力矩的幅值为变量的安全盆侵蚀研究结果表明:当波浪扰动力矩大于0.01时,安全盆开始出现侵蚀现象,当波浪扰动力矩大于1.84时,安全盆的安全域已经变成了几个离散的点,随着波浪扰动力矩继续增大,安全盆的安全域将继续严重侵蚀,直到消失为止。以波浪频率为变量的安全盆侵蚀研究结果表明:两栖型指控车的安全盆侵蚀对波浪的频率敏感,安全盆出现明显的侵蚀;随着频率的增大,安全盆侵蚀将不会发生,表明两栖型指控车对高频波浪是安全的。     

解析美国大学TESL硕士培养的主要课程与设置理据——以曼卡托明尼苏达州立大学为例

把英语作为第二语言的教学是20世纪60年代在美国兴起并逐步走向独立的科目,它在综合相关专业的同时正在朝专业化方向发展。近年来其硕士层面的教育为全球培养了大量合格的中小学英语教师,取得了较好的成绩。本文以曼卡托明尼苏达州立大学英语系为例,并结合笔者在该系攻读TESL硕士学位时的经历,解析其主要课程及设置理据。     

Quantifying the performance effects of idle time utilization in multiserver systems

In many practical multiserver queueing systems, servers not only serve randomly arriving customers but also work on the secondary jobs with infinite backlog during their idle time. In this paper, we propose a c‐server model with a two‐threshold policy, denoted by (e d), to evaluate the performance of this class of systems. With such a policy, when the number of idle servers has reached d (<c), then e (<d) idle agents will process secondary jobs. These e servers keep working on the secondary jobs until they find waiting customers exist in the system at a secondary job completion instant. Using the matrix analytic method, we obtain the stationary performance measures for evaluating different (e, d) policies. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007.     

装备表面现代维修保养技术研究

结合装备表面智能维修保养技术方面的研究成果,介绍了装甲装备故障智能检测技术、自适应、自修复功能材料,装甲装备器材全自动保养设备等先进技术,侧重装备维修保养阐述了如何提高信息化程度,推进军队武器装备维修保养技术的现代化建设。     

基于不确定性理论的研制技术风险评估方法研究

分析了装备研制技术风险的含义,根据技术风险的特点建立了评价技术风险的指标体系。在技术风险度量中引入不确定性理论的概念,并建立了基于不确定性的技术风险的度量方法,对综合技术风险进行评价。最后通过实例验证了综合评价方法的可用性。     

(修，2撤3)关键几何参数对超声速膨胀器流场和性能影响的数值研究

为了揭示关键几何参数对超声速膨胀器流动特性影响的规律,对3种隔板安装角和5种出进口面积比超声速膨胀器设计工况下的流场进行了数值研究。结果表明：随隔板安装角增加,斜激波向出口迁移,斜激波强度略有降低,超声速膨胀器膨胀比减小,效率提高;随出进口面积比增加,流道内高速区显著扩大并逐渐靠近压力面,斜激波增强,出口流动损失增加,超声速膨胀器膨胀比增大,效率降低。为获得综合性能较优超声速膨胀器结构,需在较小出进口面积比和较大隔板安装角之间做折衷选择。     

正弦波调制的光纤环本征频率测量方法

为了弥补传统光纤环本征频率测量方法中方波调制存在死区的缺陷,提出正弦波调制的本征频率测量方法。对正弦波调制下的光纤陀螺输出信号进行分析,得到二次谐波幅度与调制频率间的二次函数关系,通过计算抛物线顶点即可求得本征频率。依据该原理对已有的光纤陀螺进行升级改造,研制了一套本征频率测量系统。试验结果表明:该方法可达到1×10-5的测量精度,是一种成本低、精度高的光纤环本征频率测量方法。