The auxiliary breathing flow channel apparatus for an oxygen mask for pilots and crew of an airplane includes a flow control device with closed and open positions to regulate flow through an auxiliary channel. For instance, the same system can be used both on a chair and on a bed. The prediction module is configured to generate a prediction for a number of renormalizations to be performed to renormalize an interval range when encoding one of the symbols. Memory blocks are de-allocated asynchronously by placing associated communication resource elements in quarantine until all communication resource elements associated with the memory block are quarantined. Preferably, the impact sounds fall within the narrow frequency range of the receiver. This may occur when: a new management policy is created; a final set of a management policy is modified; a new workflow is added to the management policy; and the membership filter or explicit membership of a set referenced by the management policy’s final set is modified.