fixed a mem error
added an implementation of avg_weights()
added implementation for a sample std dev
changed the formula for the std. dev from population to sample type
renamed ar_mean to sample_mean
added a few inline comments
added 'remove_quotes' function, changed the weights lookup from ObjectId for group to text field and added a 'group_name' char to the file
Added #include <math.h> for the pow and sqrt functions used in ann.c and added a function prototype for remove_quotes()
fixed the weights lookup in mongodb
added the utils.c source file to the list of the sources; added a variable TST for the test folder
added two functions: sample_mean and sample_std_dev
Default case for the db connection error, now the compiler warnings are gone
an update to calculating the weights for devices; this will be used for calculating the weights for the groups as well
renamed calc_weights_devices.js to calc_keywords_weights.js because I added the 'group' weights calculation to the script and the name should reflect the change
removed commented out code which was not relevant anymore
added group_id and confidence_group properties to the ua_string collection
added notes about the possible normalization
added the case study