For both of the following cases, show steps to determine if the one-year principle would apply in the scenario:

Case 1: A defender has been in use for seven years and has a current salvage value of $4000. Its value one year from now is estimated to be $4000. Operating costs are $400 per year for electricity. Once a year it is overhauled at a cost of $1000.

Case 2: A defender has been in use for seven years and has a current salvage value of $4000. Its value one year from now is estimated to be $2000. Operating costs are $400 per year for electricity. Once a year it is overhauled at a cost of $1000.