Evidence for Changing of Cosmic Ray Composition between 10\u3csup\u3e17\u3c/sup\u3e and 10\u3csup\u3e18\u3c/sup\u3e eV from Multicomponent Measurements

The average mass composition of cosmic rays with primary energies between 1017 and 1018eV has been studied using a hybrid detector consisting of the High Resolution Fly\u27s Eye (HiRes) prototype and the MIA muon array. Measurements have been made of the change in the depth of shower maximum and the muon density as a function of energy. The results show that the composition is changing from a heavy to lighter mix as the energy increases. © 2000 The American Physical Society

Results from the fly’s eye experiment

We report recently analyzed results on the energy spectrum, and composition of cosmic rays above 0.3 EeV. We observe a break in the spectrum at 3 EeV and a changing composition. The results can be explained by a simple two component model: galactic cosmic rays dominated by heavy primaries and an extragalactic component dominated by light primaries. The observed isotropic arrival direction distribution is consistent with the predictions of this model. A 320 EeV event was also recorded. © 1995 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87516/2/839_1.pd

Global wealth disparities drive adherence to COVID-safe pathways in head and neck cancer surgery

Peer reviewe

Call Admission Control Jointly with Resource Reservation in Cellular Wireless Networks

To efficiently utilize the total resources and to serve mobile users demanding for different types of service, system resource utilization of these services should be considered, and efficient resource management techniques should be developed. In this paper, we propose a new call admission control (CAC) scheme jointly with resource management by considering the two service types: prioritized calls and nonprioritized calls. Proposed scheme limits the new and handoff prioritized and non-prioritized call arrivals according to call-level quality of service (QoS) requirements. By searching algorithm, admission parameters are obtained optimally and required QoS are guaranteed. Due to high priority of the prioritized calls, the admittance of non-prioritized calls into channel is restricted, while prioritized calls are admitted as long as there is sufficient bandwidth. To evaluate the performance of the proposed CAC scheme, we have compared the numerical results from the analytical model with those of New Call Bounding scheme. It is shown that the proposed CAC scheme uses the resources effectively and improves all the upper-bound QoS requirements with respect to the New Call Bounding scheme for prioritized and non-prioritized users