Perhaps you should try some spelling variations:
"modified multiobjective optimization algorithm" » "modified multiobjective optimization algorithms", "modified multiobjective optimisation algorithm", "modified multiobjective estimation algorithm"
"machine learning emotion algorithm" » "machine learning evolution algorithm", "machine learning estimation algorithm", "machine learning predation algorithm", "machine learning method algorithm"

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 multiobjective optimization algorithm") OR ("machine learning emotion algorithm"))~.
• Removing quotes may allow a broader search: (( modified multiobjective optimization algorithm ) or ( machine learning emotion algorithm ))~.
• Adding a wildcard symbol may retrieve word variants: (("modified multiobjective optimization algorithm") or ("machine learning emotion algorithm"))*.