According to some embodiments, a resource is allocated in accordance with a masked request vector. In particular, the reducing gas may be carbon monoxide and the composite may comprise rutile-phase TiO2 particles and platinum nanoclusters. A paper sensor is arranged in the paper transmitting path for detecting the position and the velocity of the document, and a control unit is connected with the paper sensor and the scanning unit to adjust the scan frequency in response to the position and the velocity of the document. The implicit ratings comprise different rating types derived from different user events and may include recency, intensity, or frequency ratings. A moving shaft provided at the other end of the link member is inserted through the pivoting plate whereby the plunger and the pivoting plate are connected with each other. It is also provided a method for converting MAC address, including: a network access device generating an MAC address from an MAC address resource pool; and replacing the source MAC address in a packet from a subscriber with said generated MAC address.