Sounds like a very bored, lonely, dog...with too much energy.
Can he not be inside of the house with you? does he live outside?
I would exercise him even more, as well as do some training. Mental excercise is very important...you have a mix of two smart breeds...that need a job to do.
Is he in obedience classes? Get enrolled in a weekly class, and do 10-15 minutes of practice training every day, twice a day. Teach him new tricks,etc.
Gina