Perhaps you should try some spelling variations:
optimization algorithm » optimization algorithms, estimation algorithm, estimation algorithms
optimisation algorithm » optimization algorithms, estimation algorithm, estimation algorithms
qoe optimization » game optimization, _ optimization, stage optimization
modified passive » modified adaptive
modified qoe » modified male, modified _, 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: "(( modified qoe optimization algorithm ) OR ( modified passive optimisation algorithm ))~".
• Adding a wildcard symbol may retrieve word variants: (( modified qoe optimization algorithm ) OR ( modified passive optimisation algorithm ))*.