The number of radio systems operating in the 2.4 GHz band is rising as a result of increased usage of wireless technologies. Since such devices interfere with one another, satisfactory co-existence becomes important. Several techniques serve to reduce the interference. Included among these are frequency hopping (FH) and power control. From the simulation results it can be seen that frequency ho...

In a recent paper, we presented a road map for how Tully's fewest switches surface hopping (FSSH) algorithm can be derived, under certain circumstances, from the mixed quantum-classical Liouville equation. In this communication, we now demonstrate how this new interpretation of surface hopping can yield significantly enhanced results for electronic properties in nonadiabatic calculations. Speci...

In Ad hoc networks, malicious nodes can enter in radio transmission range on the routing path and disrupt network activity. Therefore, protecting from intrusion of malicious node and enhance data security is an important issue on Ad hoc networks. In this study, we provide a path hopping method based on reverse AODV (R-AODV). By reverse AODV, source node builds multipath to destination and adapt...

We investigate the effects of inelastic cotunneling on the electronic transport properties of gold nanoparticle multilayers and thick films at low applied bias, inside the Coulomb-blockade regime. We find that the zero-bias conductance, g(0)(T), in all systems exhibits Efros-Shklovskii-type variable range hopping transport. The resulting typical hopping distance, corresponding to the number of ...

We evaluate the accuracy of Tully's surface hopping algorithm for the spin-boson model for the case of a small diabatic coupling parameter (V). We calculate the transition rates between diabatic surfaces, and we compare our results to the expected Marcus rates. We show that standard surface hopping yields an incorrect scaling with diabatic coupling (linear in V), which we demonstrate is due to ...

We present a scaling theory for charge transport in disordered molecular semiconductors that extends percolation theory by including bonds with conductances close to the percolating one in the random-resistor network representing charge hopping. A general and compact expression is given for the charge mobility for Miller-Abrahams and Marcus hopping on different lattices with Gaussian energy dis...

objective: to compare the effects of aerobic and stretching exercises on severity of primary dysmenorrhea. materials and methods: this randomized clinical trial was conducted on 105 female students who were suffering from primary dysmenorrhea. the participants were divided into aerobic exercise, stretching exercise, and control groups. the two intervention groups did the exercises three times a...

This paper analyzes frequency-hopping (FH) and time-hopping (TH) as multiple access format for ultrawideband communications. We apply the concept of fourthegy, recently introduced by Subramanian and Hajek, to both TH and FH.We find that the design rules are different for FCCcompliant systems(where the power spectral density is limited)than for conventional systems(where the energy per bit is li...

High impact exercise programmes can improve bone strength, but little is known about whether this type of training further benefits fracture risk by improving physical function in older people. OBJECTIVES This study investigated the influence of high impact exercise on balance, muscle function and morphology in older men. METHODS Fifty, healthy men (65-80 years) were assigned to a 6-month m...

Following stepping in-place on the surface of a rotating circular treadmill, a subject attempting to step in-place or walk in a straight line across the floor without vision will rotate relative to space. This adaptation, termed podokinetic after-rotation (PKAR), transfers to backward walking following forward walking on the rotating disk. We asked whether adaptation obtained during stepping in...