行进间跟踪轴线稳定技术

研究自行火炮行进间载体牵连给跟踪带来的扰动问题,采用补偿的方法抑制这种扰动.即采用开环前馈控制与跟踪闭环部分相结合的控制方法,取得了很好的控制效果.从扰动的机理入手,利用可测参量,对扰动部分进行线性化,并给出了补偿信号的解析式.用Matlab Simulink进行了仿真,仿真结果表明所提出的方法能够使载体的扰动造成的误差明显减少.其优点在于能够在不改变原有控制系统结构的情况下,实现有载体扰动时的跟踪轴线稳定.     

一类含变时滞扰动非线性系统的自适应鲁棒镇定

研究了一类含匹配变时滞状态扰动非线性系统的鲁棒自适应镇定问题.假定变时滞状态扰动的上界是未知的,且满足线性增长条件.基于Lyapunov稳定性理论和Lyapunov Krasovskii型泛函,设计了一种鲁棒自适应状态反馈控制器,并证明了此控制器使得闭环系统一致最终有界,且系统的状态将一致渐近趋于0.最后给出一个仿真例子说明结论的有效性.     

一类疯狂映射的Devaney混沌

本文讨论了在N=2以及纤维映射f0,f1均为旋转时,疯狂动力系统的周期点是否稠密,以及拓扑传递情况,进而得出在参数α0,α1取不同值时,疯狂动力系统的Devaney混沌情况,同时还涉及疯狂动力系统的拓扑遍历情况。     

基于一个混沌系统的保密通信及其电路实现的研究

构造一个具有复杂混沌吸引子的非线性混沌自治三维系统,对该系统的基本动力学行为进行了研究,得到了系统的分岔图和Lyapunov指数谱图,并且通过电路验证了吸引子的存在性.根据线性反馈同步理论对新系统进行同步控制,以Multisim为仿真平台构造出基于混沌系统的保密通信电路.通过加入随机白噪声干扰,观察还原信号的失真程度.仿真结果表明,在小强度噪声干扰下,混沌信号仍然能够完成对信息的有效掩盖,实现了由理论模型向现实应用的转化.     

SRD系统电子控制器的电磁兼容设计

分析了开关磁阻电动机驱动系统电子控制器的主要干扰，论述了抑制电磁干扰的技术措施，这些技术措施已成功用于7.5kW开关磁阻电动机调速系统。     

非线性扰动方程的动力学特性

用Melnikov函数方法分析了自治扰动系统的奇异轨道在扰动后的稳定流形与不稳定流形的相对位置,给出了系统分支出极限环的条件。描述了自治系统在周期扰动下的紊动性态和次谐轨道。     

Amphipod crustaceans and environmental disturbance: a review

This review of the literature shows that amphipod crustaceans create disturbance through predation on commercial harvests, attacks on macroalgae, introductions as exotic species, and interference competition. Amphipods are also affected by disturbance events, both man-made and natural. Anthropogenic disturbance includes environmental alteration by toxins, oil, organic enrichment, acidification, salinity alteration, and ships' wakes. Natural disturbances are space clearance by the feeding activities of other fauna, and physical disturbance by sediment erosion and ice scour.     

Prediction from the One‐Way Error Components Model with AR(1) Disturbances

In this paper we extend the works of Baillie and Baltagi (1999, in Analysis of Panels and Limited Dependent Variables Models, Hsiao C et al. (eds). Cambridge University Press: Cambridge, UK; 255–267) and generalize certain results from the Baltagi and Li (1992, Journal of Forecasting 11 : 561–567) paper accounting for AR(1) errors in the disturbance term. In particular, we derive six predictors for the one‐way error components model, as well as their associated asymptotic mean squared error of multi‐step prediction in the presence of AR(1) errors in the disturbance term. In addition, we also provide both theoretical and simulation evidence as to the relative efficiency of our alternative predictors. The adequacy of the prediction AMSE formula is also investigated by the use of Monte Carlo methods and indicates that the ordinary optimal predictor performs well for various accuracy criteria. Copyright © 2011 John Wiley & Sons, Ltd.     

Temporal organization patterns of epigean beetle communities (Coleoptera: Carabidae,Tenebrionidae) in different successional stages of eastern Mediterranean maquis

This two-year study explores the community structure and temporal dynamics of carabid and tenebrionid beetles in five eastern Mediterranean juniper maquis formations in relation to successional stage. Based on vegetation cover, density and soil pH, the successional stage in two of the sites (Crete, Cyprus) was an earlier state compared with the other three (Attiki, Naxos, Samos), as a result of intense goat grazing. Diversity indices and abundance distributions were compared using morphoecological surrogates of the taxa. Temporal dynamics were regulated more by cumulative species richness than by sharp phenological patterns. The higher values of niche pre-emption parameter and species turnover imply better adaptation of endemic tenebrionids to the rapid change of environmental conditions, compared with carabids. Significantly lower abundance and biomass, and higher evenness and temporal turnover for both families in Crete and Cyprus are ascribed to the reversed course of succession caused by overgrazing.     

存在不确定性干扰的生产计划──库存控制过程最优化

给出了在存在不确定性干扰的情况下，生产计划—库存控制过程最优化的动态提法．在此基础上提出了一个在线克服不确定性干扰寻求最优控制的实用算法．