GPS最优压制式干扰信号研究

针对GPS最优干扰信号评估方法欠缺的问题,提出了利用误码率判断最优干扰信号的方法。建立了卫星导航接收机模型和基于中频信号的误码率模型,研究不同干扰环境下接收机的误码率。通过改变干扰信号功率得到误码率与干信比的关系曲线,比较不同干扰信号同干信比下的误码率,得到最优干扰信号。通过实验验证,相同环境下,伪码相关干扰信号效果最优,为卫星导航信号干扰设备的研发及设计提供了依据。     

基于神经网络遗传算法的激光熔钎焊参数优化

针对激光钎焊熔深难以控制的问题,选取激光焊接功率、焊接速度等激光焊接过程中所涉及的控制参数建立基于BP人工神经网络的激光钎焊模型。根据激光钎焊模拟实验的历史数据对焊接熔深进行预测,采用遗传算法对控制参数进行优化,得到目标焊接熔深。运用MATLAB软件建立了针对铝合金/镀锌钢的激光熔钎焊过程的参数的BP人工神经网络模型,并利用遗传算法的并行和群体搜索策略,对其控制参数进行了优化,使得焊接熔深能通过过程参数精确控制,提高了接头性能。     

基于PSCAD/EMTDC的高温超导电缆模型

在PSCAD/EMTDC中对国内首条110kV冷绝缘高温超导电缆建立了模型,该模型能够反映出电流在导体层和铜骨架之间的分流情况;将MATLAB与PSCAD/EMTDC通过接口程序连接,在MATLAB中编写了导体层阻值的计算程序,该程序考虑到了温度和电流的影响,能够反映出每一个采样时间段内阻值的变化情况;设置了单相接地故障,对故障电流下超导电缆的失超过程进行了仿真,得到并分析了失超过程中电流波形图以及导体层的温度曲线。     

一种块处理模式数字滤波器的DSP实现

 对称FIR(有限冲激响应)滤波器的严格的线性相位特性和系统稳定性在数据传输、图像处理等领域得到了广泛的应用。基于单点处理模式的传统数字滤波器能实时处理点信号,但在处理图像、语音等帧信号时,速度较慢,实时性不强。针对这个问题提出了块处理模式的解决方案。通过分析FIR滤波器的原理,设计出基于块处理模式的对称FIR滤波器,并在TMS320C5510芯片中实现。介绍了基于双指针循环寻址的滤波算法,并给出了相应的主要程序。计算机试验仿真表明块处理模式方案提高了帧信号的处理速度,滤波性能良好。     

Computer simulation of Fraunhofer diffraction based on MATLAB

In this paper, we describe a novel computer simulation technique of generating Fraunhofer diffraction images from different patterns. The simulation can be performed in almost any PC using the software MATLAB. The patterns of five types of elements, including one slit, one rectangular aperture, two rectangular apertures, the grating and one circular aperture are discussed and simulated. Diffractions images can be generated for any wavelength of light and for any program are presented. Finally, the Fraunhofer diffraction optical intensity distribution is analyzed. Simulation results can improve the physics experimental teaching of Fraunhofer diffraction. The programs based on MATLAB have been used as the platform to real-time calculation and simulation and solve the optical problem.     

Computing matrix symmetrizers,finally possible via the Huang and Nong algorithm

By a theorem of Frobenius (F.G. Frobenius, Über die mit einer Matrix vertauschbaren Matrizen, Sitzungsberichte der Königlich Preußischen Akademie der Wissenschaften zu Berlin (1910), pp. 3–15 (also in Gesammelte Abhandlungen, Band 3, Springer 1968. pp. 415–427)), every matrix A _n,n over any field 𝔽 is the product of two symmetric ones. Using the algorithm of Huang and Nong (J. Huang and L. Nong, An iterative algorithm for solving finite-dimensional linear operator equations T(x)?=?f with applications, Linear Algebra Appl. 432 (2010), pp. 1176–1188) for linear systems, we develop an algorithm to compute a symmetric matrix S?=?S ^T ?∈?𝔽 ^n,n for which SA is symmetric for any given square matrix A?∈?𝔽 ^n,n where 𝔽?=?? or ?. The algorithm is implemented and tested in MATLAB.     

Different Zhang functions leading to different Zhang-dynamics models illustrated via time-varying reciprocal solving

Along with neural dynamics (based on analog solvers) widely arising in scientific computation and optimization fields in recent decades which attracts extensive interest and investigation of researchers, a novel type of neural dynamics, called Zhang dynamics (ZD), has been formally proposed by Zhang et al. for the online solution of time-varying problems. By following Zhang et al.’s neural-dynamics design method, the ZD model, which is based on an indefinite Zhang function (ZF), can guarantee the exponential convergence performance for the online time-varying problems solving. In this paper, different indefinite Zhang functions, which can lead to different ZD models, are proposed and developed as the error-monitoring functions for the time-varying reciprocal problem solving. Additionally, for the goal of developing the floating-point processors or coprocessors for the future generation of computers, the MATLAB Simulink modeling and simulative verifications of such different ZD models are further presented for online time-varying reciprocal solving. The modeling results substantiate the efficacy of such different ZD models for time-varying reciprocal solving.     

一维光子晶体的反射率特性

基于平面波展开法,设计九层一维光子晶体结构,通过改变结构中介质层的厚度,运用MATLAB编程计算一维光子晶体反射率特性,厚度差值变小时,不存在反射波的区域将增加变大。研究结果为一维光子晶体器件的设计提供理论参考。     

基于MATLAB的RC串联电路暂态过程仿真

对RC串联电路暂态过程进行了研究,并对其进行了理论分析,最后利用MATLAB的绘图功能,对实验现象进行了仿真,仿真结果与实验相符.     

Speeding up the MATLAB complex networks package using graphic processors

The availability of computers and communication networks allows us to gather and analyse data on a far larger scale than previously. At present, it is believed that statistics is a suitable method to analyse networks with millions, or more, of vertices. The MATLAB language, with its mass of statistical functions, is a good choice to rapidly realize an algorithm prototype of complex networks. The performance of the MATLAB codes can be further improved by using graphic processor units (GPU). This paper presents the strategies and performance of the GPU implementation of a complex networks package, and the Jacket toolbox of MATLAB is used. Compared with some commercially available CPU implementations, GPU can achieve a speedup of, on average, 11.3×. The experimental result proves that the GPU platform combined with the MATLAB language is a good combination for complex network research.