基于阵列协方差矩阵列向量稀疏表示的高分辨波达方向估计

提出了两种基于稀疏重构的高分辨波达方向(DOA)估计方法。对空间进行粗、细两步网格划分,并在相应的过完备基下获得阵列协方差矩阵列向量的稀疏表示,分别基于剔除及差分处理抑制噪声干扰影响。采用lp范数约束正则化迭代加权最小范数(FOCUSS)算法进行稀疏重构,在重构过程中,对过完备基进行奇异值分解并剔除奇异值小于阈值项以减小计算量,并解决过完备基条件数过大带来的病态问题。仿真结果验证了所提算法的有效性和鲁棒性。     

一种剪切波域的稀疏分量分析方法简

In applications of the image blind source separation, the traditional method of Independent Component Analysis(ICA) computes the mixed matrix by using source image directly, without using the prior knowledge that images can be represented sparsely in the transform domain, and it can not lead to a better effect. Based on the capacity of image sparse representation by shearlet, a method of sparse component analysis in the shearlet domain is presented. The image mixed source is first transformed to the shearlet domain and obtains a shearlet coefficient, then the sparsest coefficient is selected by computing kurtosis, and finally the sparse coefficient is used as the input of the ICA method to realize image separation. The complexity of the solving procedure represents a significant decrease since it chooses a less sparse coefficient. Experimental results show that, compared with the traditional ICA method, the method in this paper leads to a better separation effect and shortens the operation time of the algorithm.     

机器人避障模型简

研究了机器人在存在12个不同形状、不同大小障碍物的平面区域内避障的最短路径及最短时间路径问题.结合图论中的Dijsktra算法,获得了机器人避障的最佳路线;并对最佳路线进行了平滑处理,分别建立了问题一、二的非线性规划优化模型;利用Maple软件和Lingo软件编程,求出了最短路径、最短时间路径及切点的坐标.     

入侵杂草优化算法用于阵列天线方向图综合简

For overcoming the problem of slow convergence speed and local optimum by using the existing intelligent optimization algorithms in the pattern synthesis of antenna arrays with nulls, notches and sidelobe reduction, a novel invasive weed optimization(IWO) algorithm is presented, and an adaptive IWO is designed to improve the convergence speed and make a balance between the global and local searching ability. Simulation results show that, compared with other existing algorithms, the proposed algorithm performs better, with higher convergence speed and better computation accuracy.     

重量法标定流量计简

在利用太阳能热泵供热实验台对系统的供热性能进行实验研究时,流量计因被测介质不同及长期使用会产生实验误差.为了提高测量水平,减少误差对实验的影响,本文中的实验采用重量法,分别对室内、外管路上的LZB型玻璃转子流量计和MCE08-787型累积式流量计进行了标定,并求出了各自的流量修正系数,以此来提高实验台的测量精度,从而保证实验结果的可靠性和准确性.     

利用访问向量的内部威胁感知方法简

The hierarchy-based access control model and access vectors are defined by using the access control relationship. A method is developed for quantizing the insider threat on resources and actions in the information system. Then a full real time assessment is obtained by using access vectors. Compared with other models, this model improves the precision and objectivity of the quantization without a prior knowledge of the system. Experimental results show that the access vector based on the hand hierarchy-based access control model can effectively assess the insider threat in real-time and can be used to build the insider threat sense system.     

我国高校教师职业倦怠解析简

教师已经成为工作倦怠的高发人群之一。近几年来,我国高校教师职业倦怠问题日渐突出,教师的职业倦怠问题对学校教育教学质量的负面影响越来越严重。探析教师职业倦怠的表现、影响、产生原因,分析缓解职业倦怠的对策。有助于增强教师教学积极性,提高教学效率。     

高职院校文化生态探析简

高职院校文化生态建设面临严峻形势,重视不够,高职特点不突出、学校特色不鲜明等,制约着高职院校的发展,本文在深入分析了高职院校文化生态性质、特点和现状,旨在引起人们对高职院校文化生态建设的重视,推动高职院校文化进一步发展、完善、成熟,为高职院校健康、持续、快速发展营造良好的内在环境。     

基于地下水位动态监测系统的研究简

为了提高地下水位观测的自动化程度,设计了地下水位动态监测系统。系统的硬件电路系统以AT89S52为核心,包括传感器、模数转换器、存储器、显示模块,接口电路等。系统下位机采用单片机C语言编程,上位机采用VC＋＋编程。经调试验证,系统的运行稳定、可靠,实现了设计要求。     

变压器后备保护灵敏度分析简

不同联接组别的变压器二次侧发生两相短路故障时,流过变压器一次侧电流的大小和方向均不一致。对于单侧电源的变压器如果电流互感器的接线方式不合适,会影响保护灵敏度,因此二次侧不对称短路时,流过一次侧各相电流的大小和方向,对变压器保护非常重要。Y,Yn12低压变压器低压侧单相接地发生故障时,安装于侧过电流保护不能反应Yn侧的单相接地故障。提出了变压器后备保护的接线方式及提高低压变压器负荷侧单相接地故障灵敏度的措施。     

基于 MATLAB 的结构动力特性分析简

介绍了结构动力特性分析的基本原理和方法,利用MATLAB语言编写了结构自振频率和振型向量的求解程序.通过一个算例,表明编写的程序计算效率高,计算精度高于用ANSYS所得结果,可为求解结构自振频率和振型提供新的思路.