Perhaps you should try some spelling variations:
"modified objective optimization algorithms" » "modified objective optimisation algorithm", "modified objective estimation algorithms", "modified objective estimation algorithm", "modified multiobjective optimization algorithms"
"modified passive ventilation algorithms" » "modified passive estimation algorithms", "modified passive estimation algorithm", "modified passive convolution algorithms", "modified adaptive ventilation algorithms", "modified invasive ventilation algorithms"

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 passive ventilation algorithms") OR ("modified objective optimization algorithms"))~.
• Removing quotes may allow a broader search: (( modified passive ventilation algorithms ) or ( modified objective optimization algorithms ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified passive ventilation algorithms") or ("modified objective optimization algorithms"))*.