Perhaps you should try some spelling variations:
optimization algorithm » optimization algorithms, optimisation algorithm, estimation algorithm
qoe optimization » game optimization, _ optimization, stage optimization
using source » using morse
modified qoe » modified male, modified _, modified bi1
using force » using morse, cutting force

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( core ((using source) OR (using force)) algorithm ) or ( modified qoe optimization algorithm ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( core ((using source) OR (using force)) algorithm ) OR ( modified qoe optimization algorithm )).
• The words AND, OR and NOT may confuse the search; try adding quotes: "(( core ((using source) OR (using force)) algorithm ) or ( modified qoe optimization algorithm ))".
• Adding a wildcard symbol may retrieve word variants: (( core ((using source) OR (using force)) algorithm ) or ( modified qoe optimization algorithm ))*.