I want to power-cycle the output instead of turning it off, is it possible?

Yes. In the shutDown function, replace the command to switch off the output with a command to reset it. Here is the modified function:

function shutDown()
  if output == 0 then
    for i=1,4,1 do
      devices.system.ResetOut{output=i}
    end
  else
    devices.system.ResetOut{output=output}
  end
end

If you need a delay between the successive power off and power on, add a delay parameter to the ResetOut command to specify the delay. The statement is: devices.system.ResetOut{output=i, delay=12} or devices.system.ResetOut{output=output, delay=12} (replace 12 with the required delay).