Broadcasting is an effective way of delivering data to a large population.' In the broadcast environment under consideration, a server broadcasts data items to all clients simultaneously, according to a certain transmission schedule. Users with pending data requests need to listen to the broadcast channel until their requests are satisfied by the transmitted data. Past research on broadcast scheduling assumes that once a user starts to wait for some data item, the user waits until the desired data item is transmitted by the server. This is often not true in practice. For various reasons, users may lose patience after waiting "too long" and leave with their requests unserved.In this paper, we study the broadcast scheduling problem taking user impatience into account. Based on our analytical results, we propose a scheduling algorithm that can produce a broadcast schedule with high service ratio (i.e., percentage of requests served) as well as low mean waiting time for the requests. Performance evaluation results based on simulations are provided.

The Bi1.5MgNb1.5O7 thin films with cubic pyrochlore structure were prepared onto Pt-coated sapphire substrates by rf magnetron sputtering deposition from a stoichiometric target. Dielectric measurements indicated that the Bi1.5MgNb1.5O7 thin films exhibited low dielectric loss of ∼0.0018–0.004, medium dielectric constant of ∼86, and superior tunable dielectric properties at room temperature. A bias field of 1.6 MV/cm resulted in the maximum voltage tunability of 39%. A brief discussion is given on the enhanced tunability compared to Bi1.5ZnNb1.5O7 thin films. The low loss and superior tunability make Bi1.5MgNb1.5O7 thin films promising for potential tunable capacitor applications.

Flexible pressure sensors have attracted considerable research interest and efforts owing to their broad application prospects in wearable devices, health monitoring, and human−machine interfacing. High-sensitivity, wide-workable-range, and low-cost pressure sensors are the primary requirement in practical application. In this work, flexible pressure sensors with high sensitivity in a wide pressure range are constructed by introducing a knoll-like microstructured surface into a percolative thermoplastic polyurethane/carbon black sensitive film, using a facile, efficient, and cost-effective screen-printing route. The prepared pressure sensors exhibit an ultrawide sensing pressure range of 0−1500 kPa, high sensitivity (5.205 kPa −1 in the range of 0−100 kPa and 0.63 kPa −1 over 1200 kPa), fast response, and excellent durability for more than 30 000 cycles. We demonstrated the applications of our pressure sensors in health monitoring, such as detection of wrist radial artery pulse waves, phonation, and vibrations. In addition, the proposed sensors showed the potential in object manipulation and human−machine interfacing, capable of detecting spatial pressure distribution, measuring grip forces, and monitoring gas pressures.