Pathogenic microorganisms are detected and classified by spectral imaging of the Raman light scattered by the organisms. In particular, the artificial signal is scaled before it is transformed into an artificial wideband signal containing colored noise in both the lower and the higher frequency band. The virtual machine switching section switches a virtual machine in exection from a first virtual machine to a second virtual machine while a cache process is executed, when cache miss in a process executed by the first virtual machine is detected. When the process receives the token and the synchronization is complete, the local database is accessed and the data is used in accessing the system resource. , a floppy drive, hard drive, high-density storage medium drive, etc.