基于误差反传算法的时间序列非线性预测方法

讨论了基于误差反向传播算法的时间序列非线性预测方法，给出了用该方法预测的时间序列程序框图并对太阳黑子预测问题进行了计算机仿真。仿真结果表明该非线性预测方法有较好的预测效果．     

城市微小区电波传播预测

本文应用几何光学（ＧＯ）方法、一致性几何绕射理论（ＵＴＤ）和射线跟踪的方法对给定环境下的城市微区信道电波传播特性进行了预测     

城市微小区区域结构及其性能

给出了城市微蜂窝移动通信系统中典型的小区结构，根据射频保护比及中断概率通过计算机模拟分析了它们的性能     

岩体裂隙扩展过程的有限元仿真

利用1/4奇异元和动态网格调整技术,对岩体裂隙动态扩展过程给出了一较理想的自动跟踪方法。研制并调试完成了具有较强功能及实用性的岩体裂隙扩展过程的动态跟踪仿真程序RCPTP。该程序除能够跟踪仿真裂隙扩张过程以外,还考虑了多种工程因素(如开挖、支护等),能适应于复杂工程岩体结构的稳定性分析及变形特征超前预测。通过算例证明了本研究思想的正确性、有效性和实用性。     

香果树的快速繁殖

以香果树芽外植体在MS+6-BA 0.5mg/L+IBA 0.5mg/L培养基上进行丛芽诱导和继代培养.丛芽分化率达100%,年繁殖系数为6.3×10~5.将单个芽转移到1/2MS无机盐+MS有机物+IBA 0.5mg/L培养基上,生根率为83.1%,移栽成活率达到90%.     

BP神经网络学习算法研究

对日前应用最广的人工神经网络——BP网络的学习算法及各种改进学习算法进行了分类比较和综合分析,并结合作者的研究结果对进一步研究BP网络及算法进行了探讨.     

工程陶瓷材料去除过程研究

用有限元法对增韧氧化锆和低纯度氧化铝陶瓷依靠初始裂纹的形成,扩展和转折而实现的切屑形成和材料去除过程进行理论研究,并分析裂纹扩展路径的影响因素。所得主要结论通过现场观察和高速摄影机拍摄的系列照片得到了验证。     

Bidirectional propagation of lightning leader

The characteristics of initial leader of triggered lightning flashes are studied by use of a highspeed digital camera system with the rate of 1 000 frame per second and simultaneous measurements of current and electric field change with 0.1 μS time resolution. The results show that the altitude-triggered lightning was initiated by bidirectional propagation leader because of "current interruption" by air gap, whereas the grounded-triggered one was not. The onset of downward-moving positive leader was prior to that of the upward-going negative leader for 843 ms in an altitude-triggered lightning under the positive ambient electric field. The downward-moving leader, regardless of its polarity, would produce in-homogeneous distribution of luminosity (current) along the channel on the moment of connection to the ground.     

Feature Extraction and Classification of Echo Signal of Ground Penetrating Radar

0IntroductionGrvoeluonpde dpienne rtercaetinntg y reaardsa r, (wGhiPchR)is i se map lnoeywedte bcyh nsicqieunet idset-and engineers to obtaininformationfromsubsurface and man-made structures .It has advantage of quick,easy and non-de-structive way toi mage the first few meters of the subsurfaceSo,it is widely used in utility location,landmine detectionroad and airport runway inspection,geophysical survey,andarchaeological investigations ,etc[1 ,2]. Conventionally,radaecho signals can be form…