基于神经网络的直流电机模型辨识及应用

为了提高控制系统的控制性能,实现自适应控制,提出了一种基于神经网络模型的参数辨识方法.首先,为一台未知参数的直流电机设计了基于DSP(数字信号处理器)的控制器,再通过采集卡获取大量的实时观测数据,然后对数据进行预处理,将预处理后的数据按照神经网络辨识的原理完成模型辨识.通过比较直流电机实际阶跃响应与模型阶跃响应,对辨识模型进行检验,最后设计了该系统的PI校正装置.结果表明该方法可操作性强、辨识精度高、应用性强.     

基于实复值混合时延神经网络的宽带功放的建模和线性化（英文）

提出了一种新型的实复值混合时延神经网络,用于建模和线性化宽带射频功放.该神经网络包含输入信号的广义记忆效应、复值输入信号和复值输入信号模值的分数阶次,因而其建模精度显著提高.对实复值混合时延神经网络在不同扩展常数、记忆深度、神经元数和阶数时的归一化均方误差(NMSE)进行了比较研究,以建立一个能够有效建模宽带功放强非线性的基带模型—最优时延神经网络(TDNN).采用51 dBm宽带功放和25 MHz带宽的混合测试信号用于模型的有效性验证.测试结果表明,实复值混合时延神经网络相比记忆多项式模型和实值时延神经网络具有更高的建模精度,NMSE提高5 dB.此外,实复值混合时延神经网络相比广义记忆多项式模型,NMSE提高0.6 dB,并具有更好的数值稳定性.相比实值时延神经网络和记忆多项式模型,所提出的时延神经网络能够更好地抑制带外的频谱再生.     

柔性机构非线性运动的神经网络辨识模型

研究目的是建立柔性机构非线性运动辨识模型.柔性机构的运动形态为高度非线性,利用径向基函数(RBF)神经网络,将机构驱动力矩和机构非线性运动参数分别作为RBF神经网络的输入和输出,利用达到训练精度要求的RBF神经网络进行柔性机构的非线性运动参数的辨识.计算速度快,精度高,为复杂系统的辨识提供了一种理想的建模方法.     

基于径向基神经网络的非线性系统辨识

提出了基于径向基函数神经网络模型的系统辨识方法，由于径向基函数的神经网络比多层前馈人工神经网络模型相比，在逼近非线性函数时，具有结构简单，收敛快、且无局部极小的优点，通过计算机仿真证实了该方法具有良好的辨识效果。     

基于在线AdaBoost回归树算法的混合试验恢复力预测方法(英文)

为了解决模型更新混合试验中BP神经网络算法泛化能力较差的问题,引入了一种新方法——AdaBoost回归树算法作为混合试验中的模型更新算法.在学习阶段,选择回归树作为弱回归模型进行训练,然后将多个弱回归模型集成为一个强回归模型,最后对训练结果进行表决输出.利用在线AdaBoost回归树算法和BP神经网络算法作为模型更新算法,对一个二自由度非线性结构进行了数值模拟.结果表明,在线AdaBoost回归树算法的预测精度比神经网络高48.3%,证实了AdaBoost回归树算法比BP神经网络算法具有更好的泛化能力,并且有效消除了权重初始化的影响,提高了混合试验中恢复力的预测精度.     

基于模糊神经网络的车辆发动机建模和控制

本章针对车辆发动机是一个高度非线性、不确定的复杂系统,其模型难以建立的特点研究了基于模糊神经网络的发动机辨识技术。同时基于辨识模型和神经网络设计了发动机单变量鲁棒自适应控制系统。     

基于连续型Hopfield神经网络的系统辨识

连续型Hopfield神经网络(CHNN)可用于优化计算,但其会遭遇较复杂的参数辨识问题.为了较好地解决这一问题,将擅长全局搜索的蚁群-粒子群混合算法用于对系统参数的最优化选取.再将此混合算法与CHNN有机结合,更好地解决参数辨识问题,且能有效避免CHNN在应用过程中陷入局部最优解.最后,将理论结果应用于求解TSP问题来验证其有效性.     

基于神经网络的伺服系统辨识与内模控制

根据一组伺服驱动系统的辨识试验数据，进行了基于神经网络的非线性系统的正模型与逆模型辨识，分析了辨识结果，给出基于神经网络模型的内模控制方案，并提出了实现高速高精运动的可能方式。     

简论非线性系统的神经网络辨识

简要分析了状态-输出模型、输入-输出模型的神经网络实现。讨论了应用神经网络进行复杂系统辨识的可行性及其实现方法，并指出与基于算法的传统辨识方法相比较神经网络用于系统辨识所具有的特点。     

基于PSO优化的BP神经网络在洪水预报中的应用

针对BP神经网络的不足,采用PSO算法对BP神经网络进行优化,建立一个混合的神经网络洪水预测模型。实验仿真结果表明,该模型的预测效果优于传统的洪水预测模型。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

Western and Eastern culture differences in commercial field

The communication of people partially is the communication of cultures. Culture has a direct effect on international commercial activities in all aspects. Different conceptions about time, space, equality, law and the like, lead people to deal with things in different ways. So to know cultures of the counterpart is to facil-itate our enterprises so as to have a smooth and successful communication in commercial activity.     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

风的曲线

Rosco and I wait for the fishermen to return.I sit at a wooden bench near the store at Mt.Baker Resort and watch the clouds change shape. Rosco has my belt around his neck and an eight foot tow chain hooked to a tree. Dogs must be on a leash. Ducks and rabbits are loose.     

团图为数的图中的闭团贯数

Given a graph G,a subgraph C is called a clique of G if C is a complete subgraph of G maximal under inclusion and |C|≥2. A clique-transversal set S of G is a set of vertices of G such that S meets all cliques of G. The clique-transversal number, denoted as TC (G), is the minimum cardinality of a clique-transversal set in G. The clique-graph of G, denoted as K (G), is the graph obtained by taking the cliques of G as vertices, and two vertices are adjacent if and only if the corresponding cliques in G have nonempty intersection. Let F be a class of graphs G such that F={G|K(G) is a tree}. In this paper the graphs in F having independent clique-transversal sets are shown and thus TC (G)/|G|≤1/2 for all G ∈ F.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.