Perhaps you should try some spelling variations:
optimisation algorithm » optimization algorithms, estimation algorithm, estimation algorithms
objective optimization » multiobjective optimization
optimization algorithm » optimization algorithms, estimation algorithm, estimation algorithms
df optimisation » _ optimisation, _ optimization, qoe optimization
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 optimisation algorithm ) OR ( modified objective optimization algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (( modified df optimisation algorithm ) or ( modified objective optimization algorithm ))*.