Instituto Politécnico Nacional

About: Instituto Politécnico Nacional is a education organization based out in Mexico City, Mexico. It is known for research contribution in the topics: Population & Control theory. The organization has 43351 authors who have published 63315 publications receiving 938532 citations. The organization is also known as: Instituto Politécnico Nacional & Instituto Politecnico Nacional.

Peierls substitution in an engineered lattice potential.

Abstract: Artificial gauge fields open the possibility to realize quantum many-body systems with ultracold atoms, by engineering Hamiltonians usually associated with electronic systems. In the presence of a periodic potential, artificial gauge fields may bring ultracold atoms closer to the quantum Hall regime. Here, we describe a one-dimensional lattice derived purely from effective Zeeman shifts resulting from a combination of Raman coupling and radio-frequency magnetic fields. In this lattice, the tunneling matrix element is generally complex. We control both the amplitude and the phase of this tunneling parameter, experimentally realizing the Peierls substitution for ultracold neutral atoms.

Particle swarm optimization with fractional-order velocity

Abstract: This paper proposes a novel method for controlling the convergence rate of a particle swarm optimization algorithm using fractional calculus (FC) concepts. The optimization is tested for several well-known functions and the relationship between the fractional order velocity and the convergence of the algorithm is observed. The FC demonstrates a potential for interpreting evolution of the algorithm and to control its convergence.

Common control channel design for cognitive radio wireless ad hoc networks using adaptive frequency hopping

Abstract: Cognitive radio (CR) technology enables the opportunistic use of the portions of the licensed spectrum by the CR users, while ensuring low interference to the primary user (PU) activity in the licensed bands. The spectrum is sensed locally by the CR users, and a specific channel that is acceptable to both the end nodes of the communication link is chosen. However, this necessitates a common control channel (CCC) for exchanging the sensing information and reserving the channel before actual data transfer. In this paper, a common control channel design for CR ad hoc networks is proposed, called as adaptive multiple rendezvous control channel (AMRCC) based on frequency hopping. Our scheme is scalable, and allows continuous connectivity between the CR users under dynamic PU activity. The contribution made in this paper is threefold: (i) a frequency hopping scheme is proposed that allows altering the hopping sequence based on the PU activity in the channels, (ii) a simple and low-overhead procedure is developed to aid new node-join and leave events, and (iii) a slot duration optimization is given that avoids a significant performance degradation with the number of available channels. Performance evaluation proves that our solution achieves better performance than the other classic CCC solutions in terms of time to rendezvous (TTR) and the resulting throughput, specifically in CR ad hoc networks.