There is provided a communication apparatus including a signature selection unit that selects one signature from a plurality of signatures, and a preamble generation unit that generates a signature in random access using the preamble selected by the signature selection unit. According to this system, it is possible to readily generate micro-bubbles in an industrial scale, and the system is relatively small in size and has simple structure and can be easily manufactured. If it is determined that the number of different bits is equal to or more than the predetermined value, then the display image signal is modified so that the display panel is driven based on an analog signal converted from the modified display signal to display an image. Configuration data that includes information indicating which of the networks is associated with each of the Network Shared Disks for the one node is analyzed. The diffuser is constructed such that a low-pressure region in the area of the transition between the spiral housing and the tongue is at least reduced. Additionally provided are methods of determining the risk of ASD or ID in an individual comprising analyzing genomic mutations in PTCHD1AS1 andor PTCHD1AS2 andor PTCHD1AS3.