In a vehicular ad hoc network (VANET), the periodic exchange of single-hop status information broadcasts (beacon frames) produces channel loading, which causes channel congestion and induces information conflict problems. To guarantee fairness in beacon transmissions from each node and maximum network connectivity, adjustment of the beacon transmission power is an effective method for reducing ...

A mountain-top-to-mountain-top optical communications demonstration was conducted between the JPL Table Mountain Facility (TMF), Wrightwood, California, and Strawberry Peak (SP), Lake Arrowhead, California, during the months of August and September of 2000. The link was nearly horizontal at an altitude of 2 km and spanned a range of 46.8 km. A 780-nm multibeam beacon broadcast from TMF was rece...

Wireless sensor networks are envisioned to be an integral part of cyber-physical systems, yet wireless networks are inherently dynamic and come with varieties of uncertainties. One such uncertainty is wireless communication itself which assumes complex spatial and temporal dynamics. For dependable and predictable performance, therefore, link estimation has become a basic element of wireless net...

A nucleoside analogue comprising the ligand 1H-imidazo[4,5-f][1,10]phenanthroline (P) was applied to develop a molecular beacon capable of discriminating the canonical nucleobases cytosine and thymine. The beacon is based on the formation of a stable Ag+-mediated base pair between P and cytosine, whereas the presence of Ag+ strongly destabilizes nucleic acids comprising an artificial base pair ...

With the development of space technology and more and more space experiments, it has brought forward higher requests for memory of hard-recovered solid-state recorders. Therefore, Recovery of the memory becomes more important. Aiming at the disadvantages of present ways of recycling, we introduce a real-time GPS positioning wireless beacon which can be applied in memory recovery. This paper int...

Aiming at researching the QoS performance of slotted CSMA/CA mechanism in beacon-enabled IEEE802.15.4, this paper analyzes the effect relationship between QoS and superframe parameters through analytic mathematical model and simulation method. Firstly, the nodes’ sleeping time of WSNs is deduced from duty cycle mathematical formulation. Therefore, the energy consumption directly related to slee...