1 Click Refresh Events. New events are added to the list, and unknown traffic events return to the list if they have not been resolved.  You can also test resolving unknown traffic events by clicking My Dashboards > NetFlow > NTA Summary. You should no longer see a banner regarding unknown flow traffic.
An implicit interest rate is the nominal interest rate implied by borrowing a fixed amount of money and returning a different amount of money in the future.
Explicit Cost is the cost which is actually incurred by the organization, during production. On the other hand Implicit Cost, are just opposite to the explicit cost, as they are not directly incurred by the organization, but they are implied in nature which do not involve cash payment.