According to comparison between the calculated results , conclusions are summarized as follows : the accuracy of sensors and length of the observation time have great influence to the navigation precision in different orbit types 对高、中、低三种轨道类型,分别进行计算,通过对比可以看出,敏感器精度、观测时间长短对不同的轨道类型导航精度影响很大。
( 3 ) phase space reconstruction analysis method based on observed time series is used to analyze and identify nonlinear dynamics of rotor system . the evidence with statistical meaning representing strong nonlinear behavior is obtained （ 3 ）采用基于观测时间序列的重构相空间分析方法对转子系统的非线性行为进行辨识与分析，获得了系统出现强非线性行为的统计意义上的证据。
A faint flashlight or a dim red torch helps you write in the dark . a pencil and a sheet of paper is essential for recording the number of meteors as well as the starting and ending time of observation . remember to bring a watch along with you 一个光度暗弱的电筒，或在电筒前包著红纸，可方便记录，而铅笔和白纸更是必备的，可记下流星的数目和观测时间的始末，故此，一个手表也要用上了。
Put down the name of the observer , the place and time of observation , duration of observation , cloud cover , the sky s limiting magnitude the magnitude of the faintest star you can see with the naked eye and the number of meteors observed on the data sheet 流星雨的观测资料，只要清楚注明观测者姓名观测地点观测时间观测长度云量最暗可见星等及流星数目，便已经是一份十分有科学价值的观测记录了，很简单，对吗？
You should not observe for more than four hours during any one night , since the accuracy of your data will reduce when fatigue takes hold . to keep you alert and efficient , take a break and consume some food . warm clothing is necessary to keep your body warm 每一次观测时间的长度最好定为一小时，每一晚的观测不应多于四小时，以免身体疲倦而影响观测结果，而每段观测后应有时间作短暂休息及进食，以维持精神，增加工作效率。
A meteor shower becomes a meteor storm when the meteors hourly rate reaches several hundreds per hour . at this time , you can shorten the time of observation to 5 or 10 minutes , while the region of the sky being monitored can be reduced . these changes should also be specified on the record sheet 若在流星雨出现时，每小时的流星数目多达数百颗，称为流星暴，这时观测时间的长度可减至5到1 0分钟，而观测天区的面积也可相对地减少，这些变化也应标明于记录表上。
( 3 ) based on the study of several kinds of neural network , several phase space models of dam observation time series using neural network are established . the validity of the models is proved by an example . a neural network method for determining the component percentage is given （ 3 ）在总结分析时间序列预测中的几种有代表性的神经网络的基础上，将混沌理论和神经网络相结合，提出了几种基于神经网络的大坝观测时间序列相空间预测和监控模型，经工程实例验证，预测和监控效果较好；同时，提出了确定分量占效应量比例的神经网络方法。
Different sampling periods of sensors and the recursive steps of initial states are investigated . the navigation precision with different condition such as different precision of sensors , different length of observation time are compared . then , three orbit types , consisting of low - altitude orbit , middle - altitude orbit and high - altitude orbit , are simulated respectively 在pc机上首先分析敏感器采样周期和滤波迭代次数对自主导航精度的影响,然后比较敏感器精度不同,观测时间长短不同,轨道类型不同情况下所产生的导航误差。
In consideration of the imperfection in dam safety monitoring , the dam and slope are regarded as a dynamic system , the nonlinear science such as chaos theory , neural network and wavelet analysis is introduced to dam safety monitoring , and related models and methods are proposed hi this dissertation . the main contents are as follows . ( 1 ) according to chaos theory , the phase space reconstruction of time series is performed 本文将大坝和边坡视作一个动力系统，研究其安全监控中尚未完善的建模理论和方法等问题，将混沌理论、分形理论、神经网络、小波分析等非线性科学应用到大坝安全监控领域中，提出了大坝、边坡的安全监控非线性分析模型及方法，主要内容如下： （ 1 ）根据混沌理论，研究了大坝系统及大坝观测时间序列的混沌性。
