A ventilator having an abnormal operation indication device includes a power supply circuit, a central processing unit, a fan motor, and a load sensing circuit. The spindle has a clamping device and a transmission portion. The estimated CSI may be used in a bit metric calculation of subsequent error correction decoders, such as a Viterbi decoder, to increase system SNR gain. The metal strengthening member is configured to be compressed during a peak operating condition in which greater force is exerted into the washer assembly than during the normal operating condition. The at least one controller selects at least one of the virtual machines to migrate from one or more first physical machines to one or more second physical machines in response to the received indicators.