Perhaps you should try some spelling variations:
optimization algorithm » optimization algorithms, optimisation algorithm, estimation algorithm
graining methods » learning methods, learning method, making methods
mobile graining » mobile learning
df optimization » _ optimization, qoe optimization, _ optimisation
modified df » modified _, modified adam, modified bi1

You may be able to get more results by adjusting your search query.

• The words AND, OR and NOT may confuse the search; try adding quotes: "(( mobile graining methods algorithm ) OR ( modified df optimization algorithm ))~".
• Adding a wildcard symbol may retrieve word variants: (( mobile graining methods algorithm ) OR ( modified df optimization algorithm ))*.