Hello, this is a really nice engine,
Unfortunately it has a little bug, which happen's regularly against opponent's that ca run out of time and is easy to reproduce:

./pulse
go wtime 100 btime 0
terminate called after throwing an instance of 'std::exception'
  what():  std::exception
Aborted

This is the code in search.cpp on line 199 and 201:

if (whiteTimeLeft < 1) throw std::exception();
if (blackTimeLeft < 1) throw std::exception();

I think, those lines are not necessary and can be removed entirely (or the condition < 0).
Then Pulse would be very stable.

Best Regards,
Oliver