Page 59 - Data Science Algorithms in a Week
P. 59

Using Deep Learning to Configure Parallel Distributed Discrete-Event Simulators  43

                       (i.e., to obtain the right architecture, and one hundred for testing (i.e., to test the DBN
                       developed).
                          The  training  session  for  a  DBN  was  accomplished.  There  are  three  principles  for
                       training DBNs:

                          1.  Pre-training one layer at a time in a greedy way;
                          2.  Using unsupervised learning at each layer in a way that preserves information from
                              the input and disentangles factors of variation;
                          3.  Fine-tuning the whole network with respect to the ultimate criterion of interest
                          We have used method No. 2 for this research because is the most recognized one
                       (Mohamed  et  al.,  2011).  In  addition,  we  developed  several  standard  backpropagation
                       networks with only one hidden layer and they never converged with the training data.


                       Results

                          The finalized DBN has the following training and testing performance as shown in
                       Figure  10.  It  is  important  to  remember  that  the  training  set  was  of  200  case  studies
                       selected, the validation set with 100 case studies, and the testing set was composed of 100
                       case  studies.  The  validation  set  is  user  in  order  to  get  right  architecture  that  leads  to
                       higher performance. Figure 10 indicates the performance obtained with DBNs  for this
                       problem.






















                       Figure 10: Confusion matrix for two DBNs.

                          Stating  the  research  question  initiates  the  research  methodology  process.  This
                       investigation starts by asking: Is there a mechanism to accurately model and predict what
                       is  the  best  time  management  and  synchronization  scheme  for  a  parallel  discrete  event
                       simulation  environment  (program  and  hardware)?  Based  on  the  results,  this  was
                       accomplished in spite of the limited number of case studies.
   54   55   56   57   58   59   60   61   62   63   64