While individual Tully-style fewest switches surface hopping (FSSH) trajectories are stochastic and cannot be inverted in time, it is possible to reverse in time the dynamics of a swarm of FSSH trajectories. Here we show exactly how to invert such dynamics, and we investigate the stability of such time-reversed surface hopping dynamics. We demonstrate that FSSH trajectories can be inverted succ...

For branched polymers, the curvilinear motion of the branch point along the backbone is a significant relaxation source but details of this motion have not been well understood. This study conducts multi-chain sliplink simulations to examine effects of the spatial fluctuation and curvilinear hopping of the branch point on the viscoelastic relaxation. The simulation is based on the primitive cha...

– In the conventional theory of hopping transport the positions of localized electronic states are assumed to be fixed, and thermal fluctuations of atoms enter the theory only through the notion of phonons. On the other hand, in 1D and 2D lattices, where fluctuations prevent formation of long-range order, the motion of atoms has the character of the large scale diffusion. In this case the pictu...

Anti-jamming capability and protection against undesired interception are key priorities in ad hoc networks for secure applications. These features are supported by spread spectrum (SS) techniques such as frequency hopping (FH). In a frequency hopping ad hoc network, the phase of the hopping sequence is typically derived from the local time reference (clock reading) of each node. Therefore, net...

In this paper, the issue of control of impact forces generated during the interaction between the hopping robot toe and the ground during landing has been considered. The force thus generated can damage the robot altogether. With the objective to control these impact forces impedance control strategy has been applied to the hopping robot system. The dynamics pertaining to the impact between rob...

Abstract Aiming at the hopping time estimation problem of frequency (FH) signals under alpha stable distributed noise, a algorithm based on time-frequency pattern gradient sequence is proposed in this paper. Firstly, FH signal model and distribution noise are established according to received signals; Secondly fractional lower order SPWVD (FLOSPWVD) transform used suppress impulse pattern, clea...

A hopping robot can jump over the barrier several times higher than its own height. The combination of the hopping movement and the wheeling movement can greatly enhance the scope of robot’s activities. In this paper, a novel five-shank hopping mechanism was employed to build the wheelinghopping combination scout robot. The nonlinear character of the five-shank hopping mechanism was analyzed an...

Jamming is an effective denial-of-service (DoS) attack in wireless networks due to the open nature of radio propagation. In Jamming attack, the attacker purposely emits radio signals to corrupt the ongoing communication between the legitimate transmitter and receiver. Channel hopping is a feasible link-layer method for preventing jamming attack in wireless communications. In this paper, we prop...

To speed up the convergence of reinforcement learning (RL) algorithms by more efficient use of computer simulations, three algorithmic techniques are proposed: Time Manipulation, Time Hopping, and Eligibility Propagation. They are evaluated on various robot control tasks. The proposed Time Manipulation [1] is a concept of manipulating the time inside a simulation and using it as a tool to speed...

Silver vanadate glasses show electrical conductivity higher than 10 S cm, caused by the electron hopping from V to V together with an ionic conduction due to Ag. Lithium vanadate glasses show electrical conductivity of the order of 10 S cm which is primarily due to an electron hopping from V to V. Fraction of the Ag or Li conduction and that of electron hopping from V to V can be estimated by m...