Provided are a sheet feeding device with improved separatingfeeding performance. Arrival time traversal and required time traversal are performed for the arrival paths and required paths based on assumptions made for the delay-impacting parameters associated with the path elements. Accordingly, it is possible to provide a physical instance complying with a user’s request as a physical host. The video programs cached at the cable system hubs are determined based on attributes associated with individual video programs including time since initial release, association with other programs, association with hub locations, association with current events, and the like. The housing is configured to be securely attached to an interior wall portion of a second chamber of the heart, wherein the transceiver is configured to communicate with an external device through the RF energy. One such method comprises: determining components of a propagation path of a base station of a communication network; determining a propagation delay associated with each of the components; and determining a delay of the propagation path using the delays of the components.