DictionaryofAppliedMathforEngineersandScientists

介绍经验模态分解的emd算法上下包络线的形成过程(Introduction emd empirical mode decomposition algorithm for the upper and lower envelope formation)

Modelo de dos rayos de Andrea Goldsmith (figura 2.5, según expresión 2.12) f = 0.9 frecuencia en GHz landa = 0.3/f en m R = -1 coeficiente de reflexión en tierra ht = 10 altura del transmisor en m hr = 2 altura del receptor en m Gt = 1 Gr = 1 Pt = 1 d=10:.1:100000 phase_diff = 4*pi*ht*hr./(landa*d) aproximación Pr = Pt*((landa/(4*pi))^2)*((abs((sqrt(Gt)./d) + (R*sqrt(Gr).*(exp(-sqrt(-1)*phase_diff)))./d)).^2) Pr = Pt*((landa/(4*pi))^2)*(1./d).*((abs((sqrt(Gt)) + (R*sqrt(Gr).*(exp(-sqrt(-1)*phase_diff))))).^2) figure(1), clf, plot((d),10*log10(Pr/max(abs(Pr)))) grid xlabel( log_1_0(d) ) ylabel( Potencia recibida (dBm) )

说明：  This code is used for trajectory tracking using PF.

用HOUGH检测直线的时候是两个未知量,因为轴半径和相角可以确定一条直 线，在HOUGH域出现累计最大点就可能是原域中的直线。现在回到圆的检测 上来，确定一个圆需要什么：X坐标，Y坐标，半径三个未知量吧，好了，现在， 你做一个三维空间的HOUGH域，以这三个未知量作为三个轴，现在按照一定步长 进行三重循环，在最内层循环是这样的，X,Y 确定，以不同的半径进行搜索，如 果你的X,Y刚好就是实际图像的X,Y处，半径又搜索到实际真实的半径(The HOUGH detect straight when two unknown amount of axis radius and phase angle can be determined in a straight line, in the HOUGH domain cumulative maximum point may be the straight line of the original domain. Now back to the circle detection up to determine what a circle: X coordinate, Y coordinate, radius three unknowns, now, you do the HOUGH domain of a three-dimensional space, three to three unknown quantity as axis, in accordance with a certain step size triple loop, is such that in the innermost loop, X, and Y determined search for a different radius, If you X, Y, exactly is the actual image of the X, Y, at the radius radius of the search to the actual real)

给出了三种动态子结构方法的程序，对比了自由界面模态综合法，固定界面模态综合法，双协调自由界面模态综合法三种方法。(Shows three dynamic substructure method of procedure, compared to the free interface modal synthesis method, fixed-interface modal synthesis method, two-coordinate free interface modal synthesis method of three methods.)

减聚类的类代码，可以直接使用获得类中心，类数目(Clustering by class code, you can directly use a type of center, type the number of)

说明：  基于特征点的图像拼接，但需要人工选择特征点。(Based on feature points of the image stitching, but the need to manually select feature points.)

Numerical solution of 1D wave equation in finite differences (matlab code)

matlab GUI的使用，对初学者来说是很好的资料。(matlab GUI for use, for beginners is good information.)

说明：  （2，1，7）卷积码，用matlab实现((2,1,7) convolutional code with matlab implementation)