Perhaps you should try some spelling variations:
"modified parameters optimization algorithm" » "modified parameter optimization algorithm", "modified parameter estimation algorithm", "modified parameters optimization algorithms", "modified parameters optimisation algorithm", "modified parameters estimation algorithm"
"modified virus prediction algorithm" » "modified virus predation algorithm", "modified virus predators algorithm", "modified fire prediction algorithm", "modified risk prediction algorithm"

Try widening your search to All Fields.

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

• Performing a fuzzy search may retrieve terms with similar spellings: (("modified virus prediction algorithm") or ("modified parameters optimization algorithm"))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("modified virus prediction algorithm") OR ("modified parameters optimization algorithm")).
• Removing quotes may allow a broader search: (( modified virus prediction algorithm ) or ( modified parameters optimization algorithm )).
• Adding a wildcard symbol may retrieve word variants: (("modified virus prediction algorithm") or ("modified parameters optimization algorithm"))*.