ÿþ<html> <head> <meta http-equiv=Content-Type content="text/html; charset=unicode"> <title>Test 2</title> <meta http-equiv=Content-Language content=en-us> </head> <body bgcolor="#D7D6DA" text="#5A3C38"> <p><strong>Instructions:</strong></p> <ol> <li>please download <a href="http://www.caida.org/~dima/test2/test2.tar.gz"><u>this file</u></a> containing a dataset and the code used in <a href="http://dx.doi.org/10.1103/PhysRevLett.94.018102"><u>this paper</u></a> (thanks to Dante Chialvo for the permission to use this data/code in this assignment)</li> <li>unzip and compile the code as instructed in reader.f</li> <li>run the program as instructed, and it will produce the full correlation matrix for all voxel pairs in the brain (see the paper)</li> <li>form networks from this correlation matrix: let voxels <i>v<sub>1</sub></i> and <i>v<sub>2</sub></i> be connected if the correlation coefficient between them exceeds threshold <i>r<sub>c</sub></i>, <i>r</i>(<i>v<sub>1</sub></i>,<i>v<sub>2</sub></i>) &gt; <i>r<sub>c</sub></i> &gt; 0</li> <li>find an approximate percolation transition value of <i>r<sub>c</sub></i>, i.e., its value <i>r'<sub>c</sub></i> corresponding to the onset of the giant connected component in the resulting networks</li> <li>compute basic network properties (see below) for the network with this <i>r'<sub>c</sub></i></li> </ol> <p><strong>Completed assignment:</strong><br> is a zipped file which includes: </p> <ul> <li>the estimated percolation transition value of the correlation coefficient threshold <i>r'<sub>c</sub></i></li> <li>a short description of how this value was estimated</li> <li>the size, average degree, and average clustering in the network with this <i>r'<sub>c</sub></i></li> <li>the raw data for the degree distribution <i>P</i>(<i>k</i>), average degree of neighbors of nodes of degree <i>k</i> (ANND), and average clustering of nodes of degree <i>k</i> in this network</li> <li>the properly logbinned plots of the last three statistics</li> </ul> <p><strong>Assignment questions:</strong><br> can be directed to <a href="mailto:jobs+net.qs@caida.org"><u>jobs+net.qs@caida.org</u></a> </p> </body> </html>