PDE Toolbox和最小二乘法在导热问题中的应用

设计金属加热的控制策略,首先要获得金属导热体的开环系统模型.针对一个带有矩形孔的金属薄板上的热传导问题,采用PDE Toolbox进行求解和仿真,并用最小二乘方法进行热传导系统的建模与仿真,以获得模型中的参数.将此参数与求解微分方程方法所得到的数据进行对比,结果表明,采用最小二乘法可以更清楚地了解金属板的外部特性,并获得输入输出信号的差分方程,而求解微分方程的方法则显示了金属板的内部特性,两种方法是等效的.     

Mean square exponential stability in high-order stochastic impulsive BAM neural networks with time-varying delays

In this paper, a class of stochastic impulsive high-order BAM neural networks with time-varying delays is considered. By using Lyapunov functional method, LMI method and mathematics induction, some sufficient conditions are derived for the globally exponential stability of the equilibrium point of the neural networks in mean square. It is believed that these results are significant and useful for the design and applications of impulsive stochastic high-order BAM neural networks.     

基于最小二乘支持向量机的机器视觉识别方法

为了解决传统的机器视觉识别技术识别精度低的难题,提出基于粒子群优化最小二乘支持向量机的机器视觉识别方法.首先,对机器视觉采集的图像进行特征提取;然后,利用特征数据建立基于粒子群优化最小二乘支持向量机的识别模型;最后,以红枣缺陷识别作为应用案例以证明该方法的有效性及优越性.分别采用人工神经网络、支持向量机与该方法进行对比...     

Random linear-quadratic mathematical models: Computing explicit solutions and applications

This paper deals with the study of linear random population models and with a random logistic model (where parameters are random variables). Assuming appropriate conditions, the stochastic processes solutions are obtained under closed form using mean square calculus. Expectation and variance expressions for the stochastic processes solutions are given and illustrative examples are included.     

Model predictive control for systems with stochastic multiplicative uncertainty and probabilistic constraints

Robust predictive control handles constrained systems that are subject to stochastic uncertainty but propagating the effects of uncertainty over a prediction horizon can be computationally expensive and conservative. This paper overcomes these issues through an augmented autonomous prediction formulation, and provides a method of handling probabilistic constraints and ensuring closed loop stability through the use of an extension of the concept of invariance, namely invariance with probability p.     

基于近红外与高光谱技术的小麦种子多指标检测方法

采集47份小麦样本的高光谱图像,提取感兴趣区内的平均光谱,结合反映小麦品质的水分、蛋白质和湿面筋三个指标基础数据,通过OPUS软件搜寻最佳的光谱预处理和波段组合,分别建立了三个指标的偏最小二乘法(PLS)定量分析模型.同时与采用近红外(.NIR)光谱技术建立的三个指标的近红外模型进行比较,发现高光谱模型的各性能指标均明显优于近红外模型.结果表明:当被测样品为颗粒状且内部化学成分分布不均匀时,近红外模型的准确性和稳定性会受其测量条件的限制,而高光谱采样面积大,获取信息更全面,展现出强大的分析检测潜质,为小麦品质评价提供了新方法.     

Nonlinear aircraft sensor fault reconstruction in the presence of disturbances validated by real flight data

This paper proposes an approach for Inertial Measurement Unit sensor fault reconstruction by exploiting a ground speed-based kinematic model of the aircraft flying in a rotating earth reference system. Two strategies for the validation of sensor fault reconstruction are presented: closed-loop validation and open-loop validation. Both strategies use the same kinematic model and a newly-developed Adaptive Two-Stage Extended Kalman Filter to estimate the states and faults of the aircraft. Simulation results demonstrate the effectiveness of the proposed approach compared to an approach using an airspeed-based kinematic model. Furthermore, the major contribution is that the proposed approach is validated using real flight test data including the presence of external disturbances such as turbulence. Three flight scenarios are selected to test the performance of the proposed approach. It is shown that the proposed approach is robust to model uncertainties, unmodeled dynamics and disturbances such as time-varying wind and turbulence. Therefore, the proposed approach can be incorporated into aircraft Fault Detection and Isolation systems to enhance the performance of the aircraft.     

基于表面深度值均方差的航空行李分类研究

以航空旅客行李托运方式的国际标准为出发点,研究了基于行李表面深度值均方差的分类方法,为采取何种方式托运提供依据。采用Kinect传感器在行李输送带上方采集深度图像,提取行李区域的像素值并计算其均方差进行粗分类;结合行李三维形态的先验知识,根据网格之间的距离以及深度值均方差的差异,设计了基于网格相似度的自适应聚类算法,拟合聚类结果中高层单元的面积和数量,分析行李三维形态特征,确定其类别。实验结果表明,所提算法复杂度低,能快速准确地识别行李类别。     

无线通信系统信道估计技术研究现状

信道估计技术是未来无线通信系统得以实际应用的关键技术。首先介绍了无线通信系统信道模型的特点以及信道估计方法分类,然后重点阐述了目前无线通信系统中非盲信道估计方法的研究现状,并对各种算法的优缺点和性能进行了分析和比较。