In this paper , we analyze the statistic characters of time - delay in detail , and put forward to adopt elman nn to forecast time - delay intelligently , design appropriate compensator based on adaptive smith forecast theory . the experiment results prove that this method can improve the forecast accuracy and system ' s dynamic performance . in the application of real time data transmission , forward error correction ( fec ) is a good method to resume the lost data 针对这个问题本文进行了详尽的统计特性分析，并且提出采用elman动态神经网络结构对网络时延进行智能预测，并根据自适应smith预估补偿控制原理设计合适的时延补偿器，并且应用于基于web的二阶水位控制系统中，实验结果证明了采用此方法可以提高预测精度，使时延补偿器适应时延变化的动态性更强，从而在保证系统稳定性的基础上，西安理工大学硕士学位论文提高系统的时延补偿精度。
2 . a scheme of instrument fault detection in boiler water level control system is presented based on the parity space method . the processes of the fault detection of instruments of steam flow , feed - water flow , and water level are introduced , the effectiveness of the fault detection scheme presented is shown by the simulation results （ 2 ）将一致空间算法（ willsky - chow方法）用在汽包水位三冲量控制系统中，提出了对于汽包水位控制系统的仪表故障进行快速准确检测的新方法，仿真结果表明该方法能够快速、准确实现故障的检测。
