Perhaps you should try some spelling variations:
optimization algorithm » optimization algorithms, estimation algorithm, estimation algorithms
objective optimisation » objective optimization, multiobjective optimization
optimisation algorithm » optimization algorithms, estimation algorithm, estimation algorithms
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.

• If you are trying to use Boolean operators, they must be ALL CAPS: (( modified df optimization algorithm ) OR ( modified objective optimisation algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (( modified df optimization algorithm ) or ( modified objective optimisation algorithm ))*.