Controlling a leaky tap

We apply the Ott, Grebogy and Yorke mechanism for the control of chaos to the analytical oscillator model of a leaky tap obtaining good results. We exhibit the robustness of the control against both dynamical noise and measurement noise.A possible way of controlling experimentally a leaky tap using magnetic-field-produced variations in the viscosity of a magnetorheological fluid is suggested.Comment: 14 pages, 12 figures. Submitted to Physics Letters

Lagrangian Description of the Variational Equations

A variant of the usual Lagrangian scheme is developed which describes both the equations of motion and the variational equations of a system. The required (prolonged) Lagrangian is defined in an extended configuration space comprising both the original configurations of the system and all the virtual displacements joining any two integral curves. Our main result establishes that both the Euler-Lagrange equations and the corresponding variational equations of the original system can be viewed as the Lagrangian vector field associated with the first prolongation of the original LagrangianAfter discussing certain features of the formulation, we introduce the so-called inherited constants of the motion and relate them to the Noether constants of the extended system

Control of Current Reversal in Single and Multiparticle Inertia Ratchets

We have studied the deterministic dynamics of underdamped single and multiparticle ratchets associated with current reversal, as a function of the amplitude of the external driving force. Two experimentally inspired methods are used. In the first method the same initial condition is used for each new value of the amplitude. In the second method the last position and velocity is used as the new initial condition when the amplitude is changed. The two methods are found to be complementary for control of current reversal, because the first one elucidates the existence of different attractors and gives information about their basins of attraction, while the second method, although history dependent, shows the locking process. We show that control of current reversals in deterministic intertia ratchets is possible as a consequence of a locking process associated with different mean velocity attractors. An unlocking efect is produced when a chaos to order transition limits the control range.Comment: to be published in Physica A - 11 pages - 10 figure

Current reversal with type-I intermittency in deterministic inertia ratchets

The intermittency is investigated when the current reversal occurs in a deterministic inertia ratchet system. To determine which type the intermittency belongs to, we obtain the return map of velocities of particle using stroboscopic recording, and numerically calculate the distribution of average laminar length ${}$. The distribution follows the scaling law of ${} \propto {\epsilon}^{-1/2}$, the characteristic relation of type-I intermittency.Comment: 4 pages, 7 figure

Quantum Game Techniques Applied to Wireless Networks Communications

In order to analyze the power control problem, the wireless quantum network nodes are modeled as players at a quantum game. The power control problem is one of the most significant wireless communications challenges which characteristics make it proper to be modeled by means of game theory techniques. The problem results in non-cooperative game by nature, but, under quantum rules, a larger strategy space leads the players to choose a coalition strategy as the best option. Thus, the use of quantum game strategies makes possible the emergence of new equilibrium, which guarantees the best possible performance to the whole network. We show also that the whole network power consumption decreases when the intrinsic parallel behavior of quantum computation is capitalized. Moreover, the design of efficient medium access control algorithms is possible

Quantum Games Based Communication Protocols

 Medium access control (MAC) and efficient spectrum allocation function particularly, are real challenges that wireless communications are facing nowadays and Dynamic Spectrum Access (DSA), enhanced with quantum computation techniques, is the most promising alternative. In such a context, we capitalize quantum games and quantum decisions strengths to design protocols that make classic communications more efficient. That is, we focus on protocols running on quantum devices whose input and output signals are classic. In this work we propose a quantum media access control (QMAC) that allows dynamic and fair spectrum allocation. Particularly, we point to two of the main DSA functions, which are Spectrum Sharing and Spectrum Allocation

Quantum Game Techniques Applied to Wireless Networks Communications

In order to analyze the power control problem, the wireless quantum network nodes are modeled as players at a quantum game. The power control problem is one of the most significant wireless communications challenges which characteristics make it proper to be modeled by means of game theory techniques. The problem results in non-cooperative game by nature, but, under quantum rules, a larger strategy space leads the players to choose a coalition strategy as the best option. Thus, the use of quantum game strategies makes possible the emergence of new equilibrium, which guarantees the best possible performance to the whole network. We show also that the whole network power consumption decreases when the intrinsic parallel behavior of quantum computation is capitalized. Moreover, the design of efficient medium access control algorithms is possible

Chaotic Dynamics in Kicked Ratchets

AbstractA one-dimensional deterministic continuous dynamical system is studied and shown to exhibit chaotic behavior and complex trans- port properties. Our model is an overdamped rocking ratchet with finite dissipation that is periodically kicked with a delta function driving force, without finite inertia terms or temporal or spatial stochastic forces. This is perhaps the simplest model reported in the literature for a ratchet that exhibits a complex chaotic behavior. We present both numerical and analytical results that predict many key features of the system, such as current reversals, as well as the presence of chaotic behavior and bifurcation. In particular, we show that alternate positive and negative delta functions as the unbiased driving force on a ratchet potential produces both synchronized and chaotic regions