An impact-resistant apparatus includes support members for supporting the apparatus on a surface, an impact sensor for sensing an impact, and means for aborting a predetermined operation based on an output from the impact sensor. A dual table drive and interchangeable head arrangement make the machine also suitable for conventional turret lathe operations. The spatial light modulator and phase mask can be implemented in a liquid crystal SLM, in a DMD SLM, in a magneto-optical SLM, or in any other suitable manner. Embodiments determine an Ethernet port of the source switch module on which to transmit the packet, based on the received path information. The system may further include a context engine to identify a region of interest including at least a part of the one or more objects of interest, and scale the region of interest within individual image frames to emphasize the objects of interest. In the base layer other than the base layer formed immediately above the base substrate, the first group-III nitride layer has a thickness of 50 nm or more and 100 nm or less and the second group-III nitride layer satisfies 0\u2266yy\u22660.