考虑铁损的异步电机仿真建模

指出了MATLAB／Simulink电气系统模块库所提供的异步电机仿真模型存在的问题，推导出两相静止坐标系下考虑铁损的异步电机动态数学模型，进而建立了基于Simulink平台考虑铁损的三相异步电机仿真模型。仿真实例验证了该模型能真实地反映电机实际物理过程，具有稳定性好，简单易于实现，可多提供电机内部物理量等优点。     

关于不定期多阶段决策问题的策略空间迭代法

利用图论知识,对不定期多阶段决策问题的策略空间迭代法的概念和方法,给出一种确切和完整的新的论述。     

内燃机驱动的自激异步发电系统建模仿真研究

基于Matlab/Simulink软件建立了异步发电机仿真模型,针对采用的笼型异步电动机数据,确定了M文件中异步发电机模型中的相关参数;详细说明了四冲程内燃机在Matlab软件下的建模实现过程和原理;建立了以内燃机为原动机的自激异步发电系统。仿真结果表明,接入负载时,系统有明显的调整过程,通过对比分析有无原动机时电压的变化情况验证了模型的正确性,为实际内燃机驱动的自激异步发电系统研制提供了强有力的理论依据。     

Approximate policy iteration: a survey and some new methods

We consider the classical policy iteration method of dynamic programming(DP),where approximations and simulation are used to deal with the curse of dimensionality.We survey a number of issues:convergence and rate of convergence of approximate policy evaluation methods,singularity and susceptibility to simulation noise of policy evaluation,exploration issues,constrained and enhanced policy iteration,policy oscillation and chattering,and optimistic and distributed policy iteration.Our discussion of policy evaluation is couched in general terms and aims to unify the available methods in the light of recent research developments and to compare the two main policy evaluation approaches:projected equations and temporal differences(TD),and aggregation.In the context of these approaches,we survey two different types of simulation-based algorithms:matrix inversion methods,such as least-squares temporal difference(LSTD),and iterative methods,such as least-squares policy evaluation(LSPE) and TD(λ),and their scaled variants.We discuss a recent method,based on regression and regularization,which recti?es the unreliability of LSTD for nearly singular projected Bellman equations.An iterative version of this method belongs to the LSPE class of methods and provides the connecting link between LSTD and LSPE.Our discussion of policy improvement focuses on the role of policy oscillation and its effect on performance guarantees.We illustrate that policy evaluation when done by the projected equation/TD approach may lead to policy oscillation,but when done by aggregation it does not.This implies better error bounds and more regular performance for aggregation,at the expense of some loss of generality in cost function representation capability.Hard aggregation provides the connecting link between projected equation/TD-based and aggregation-based policy evaluation,and is characterized by favorable error bounds.     

面向分组密码的NCL电路处理模型

根据分组密码操作方式的特点,提出一种面向分组密码处理的NCL电路模型。采用双异步流水线并行工作方式、线性握手和非线性握手混合的握手方式以及基于NCL闭环流水线的控制方式,将AES算法在该模型上进行映射,使用异步电路综合工具Balsa在1 µm工艺下进行综合和仿真,结果证明该模型有效。     

面向并行备份数据流的数据快速存储方法

在大规模数据服务应用中,尤其是备份与共享系统中,服务器往往会面临大量的上行数据流,而对这些数据的处理需要进行频繁的写操作,由于服务器数据存储位置的随机性,在多用户多任务环境下磁盘性能大大降低.传统的缓存技术只是针对小范围数据的局部性进行优化,对于并行备份数据流的效果不好,因此提出一种数据缓冲方法,通过数据封装,对上行数据流进行整理,动态调整IO次序,实现异步的数据处理接口,提高了文件服务器的存储性能.     

一种有效的新预条件Gauss-Seidel迭代法

为了改善古典迭代法的收敛速度,本文提出一种带参数的新预条件方法,并对参数的选择给出必要条件,证明了对于非奇异不可约M一矩阵,新预条件方法收敛且可以加速Gauss—Seidel迭代法的收敛速度,数值例子表明新预条件方法是有效的．     

快速高精度除法算法的FPGA实现

为在现场可编程门阵列(FPGA)中实现快速高精度除法,在传统的倒数除法的基础上,提出一种改进算法.对倒数求解采用泰勒级数展开结合优化搜索逼近,求出各个分区间内的拟合一次两项式,再通过一次牛顿迭代提高精度.时序仿真结果表明,以该算法构建的除法器易于在FPGA上实现,时延仅为6个时钟周期,能达到2(-34)的有效精度和86...     

基于网络延时的异步航迹融合

针对分布式传感器网络中广泛存在的通信延时问题,在异步航迹融合的基础上,提出一种基于网络通信延时的异步航迹融合算法。该算法对通信延时情况进行模拟,能自动地对产生延时的传感器进行跟踪和检测,并做出相应处理。算法具有较高的灵活性和较强的实用性。对数据传输延时的影响进行分析,通过仿真实验比较了数据传输延时对航迹融合效果的影响。     

A piecewise variational iteration method for treating a nonlinear oscillator of a mass attached to a stretched elastic wire

In this paper, we introduce a piecewise variational iteration method for treating a nonlinear oscillator of a mass attached to a stretched elastic wire. For the nonlinear oscillator, the present method can produce a good approximation to the exact solution in a very large region, while the standard variational iteration method (VIM) gives a good approximation only in a small region. The numerical results obtained show that the present method does not share the drawback of the standard VIM and can provide very accurate analytical approximate solutions for both small and large values of the oscillation amplitude and parameter.