Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.astro.spbu.ru/DOP/A-PERC/usrnotes.ps Дата изменения: Fri Nov 19 12:11:48 2010 Дата индексирования: Mon Oct 1 21:43:19 2012 Кодировка: Поисковые слова: south pole

Some remarks for users
The code producing data for the database has been written in two languages -- Pascal and
Fortran. The program files are called NeuroCluster.pas and NeuroCluster.for, respectively.
The code reads some weights form the files ww 11x, ww 12x (where x=pas for Pascal and
x=for for Fortran), some numbers from a file data and output results in the file a 11 12.txt.
The files ww 11x and ww 12x (e.g., ww 11pas, ww 11for, etc.) contain the weights of
the artificial neural network (the two layer perceptron) which are used to calculate the expansion
coefficients a 11 and a 12 of the scattering matrix elements S 11 and S 12 (contact the authors (link)
for a code that calculates these weight for different parameter values).
The file data sets the input vector of the perceptron and the range of the scattering angles
within which the calculations have to be performed. Since the perceptron has been so far trained
for the fractal dimension D = 3, the density ae = 8 and the size parameter of cluster's grain x = 1:5,
the free parameters in the input vector are the real and imaginary parts of refractive index m and
the number of grains in the cluster N . The structure of the input file data is as follows:
theta min theta max del theta
0 180 2
Re(m) Im(m) N
1.70 0.001 10
Here, as it has been mentioned in the Description, theta min, theta max, del theta (all in degree)
are the minimum and maximum values, and the step of change of the scattering angles at which
the scattering matrix elements are calculated. Re(m) (1.4 ! Re(m) ! 1.71) and Im(m) (0.001 !
Im(m) ! 0.1) are the real and imaginary parts of the complex refractive index of cluster's grain, N
(N ! 50) is the number of grains in the cluster.
Note that the files ww 11x, ww 12x (e.g., ww 11pas, ww 12pas) and data must be in the
same directory as the program NeuroCluster.pas (or NeuroCluster.for)!
The output file a 11 12.txt contains the expansion coefficients of the scattering matrix element
a 11 and a 21 in series of the generalized spherical function as well as the angular dependencies of the
scattering matrix elements S 11 , S 21 and the degree of linear polarization P (P = \GammaS 21 =S 11 ). The
matrix elements are normalized in the way that integration of S 11 over all scattering angle gives
the scattering effeciency Q sca .