Search results for "System dynamics"
showing 10 items of 230 documents
Stochastic Response Of Fractionally Damped Beams
2014
Abstract This paper aims at introducing the governing equation of motion of a continuous fractionally damped system under generic input loads, no matter the order of the fractional derivative. Moreover, particularizing the excitation as a random noise, the evaluation of the power spectral density performed in frequency domain highlights relevant features of such a system. Numerical results have been carried out considering a cantilever beam under stochastic loads. The influence of the fractional derivative order on the power spectral density response has been investigated, underscoring the damping effect in reducing the power spectral density amplitude for higher values of the fractional de…
Moment Equations for a Spatially Extended System of Two Competing Species
2005
The dynamics of a spatially extended system of two competing species in the presence of two noise sources is studied. A correlated dichotomous noise acts on the interaction parameter and a multiplicative white noise affects directly the dynamics of the two species. To describe the spatial distribution of the species we use a model based on Lotka-Volterra (LV) equations. By writing them in a mean field form, the corresponding moment equations for the species concentrations are obtained in Gaussian approximation. In this formalism the system dynamics is analyzed for different values of the multiplicative noise intensity. Finally by comparing these results with those obtained by direct simulat…
Cooling of Many-Body Systems via Selective Interactions
2018
We propose a model describing $N$ spin-1/2 systems coupled through $N$-order homogeneous interaction terms, in presence of local time-dependent magnetic fields. This model can be experimentally implemented with current technologies in trapped ions and superconducting circuits. By introducing a chain of unitary transformations, we succeed in exactly converting the quantum dynamics of this system into that of $2^{N-1}$ fictitious spin-1/2 dynamical problems. We bring to light the possibility of controlling the unitary evolution of the $N$ spins generating GHZ states under specific time-dependent scenarios. Moreover, we show that by appropriately engineering the time-dependence of the coupling…
Temperature effects on quantum non-Markovianity via collision models
2018
Quantum non-Markovianity represents memory during the system dynamics, which is typically weakened by the temperature. We here study the effects of environmental temperature on the non-Markovianity of an open quantum system by virtue of collision models. The environment is simulated by a chain of ancillary qubits that are prepared in thermal states with a finite temperature $T$. Two distinct non-Markovian mechanisms are considered via two types of collision models, one where the system $S$ consecutively interacts with the ancillas and a second where $S$ collides only with an intermediate system $S'$ which in turn interacts with the ancillas. We show that in both models the relation between …
Landauer’s Principle in Multipartite Open Quantum System Dynamics
2015
We investigate the link between information and thermodynamics embodied by Landauer's principle in the open dynamics of a multipartite quantum system. Such irreversible dynamics is described in terms of a collisional model with a finite temperature reservoir. We demonstrate that Landauer's principle holds, for such a configuration, in a form that involves the flow of heat dissipated into the environment and the rate of change of the entropy of the system. Quite remarkably, such a principle for {\it heat and entropy power} can be explicitly linked to the rate of creation of correlations among the elements of the multipartite system and, in turn, the non-Markovian nature of their reduced evol…
Perturbative Treatment of the Evolution Operator Associated with Raman Couplings
2006
A novel perturbative treatment of the time evolution operator of a quantum system is applied to the model describing a Raman-driven trapped ion in order to obtain a suitable 'effective model'. It is shown that the associated effective Hamiltonian describes the system dynamics up to a certain transformation which may be interpreted as a 'dynamical dressing' of the effective model.
Dynamics of quantum correlations in two-qubit systems within non-Markovian environments
2012
Knowledge of the dynamical behavior of correlations with no classical counterpart, like entanglement, nonlocal correlations and quantum discord, in open quantum systems is of primary interest because of the possibility to exploit these correlations for quantum information tasks. Here we review some of the most recent results on the dynamics of correlations in bipartite systems embedded in non-Markovian environments that, with their memory effects, influence in a relevant way the system dynamics and appear to be more fundamental than the Markovian ones for practical purposes. Firstly, we review the phenomenon of entanglement revivals in a two-qubit system for both independent environments an…
Quantum resonant activation
2017
Quantum resonant activation is investigated for the archetype setup of an externally driven two-state (spin-boson) system subjected to strong dissipation by means of both analytical and extensive numerical calculations. The phenomenon of resonant activation emerges in the presence of either randomly fluctuating or deterministic periodically varying driving fields. Addressing the incoherent regime, a characteristic minimum emerges in the mean first passage time to reach an absorbing neighboring state whenever the intrinsic time scale of the modulation matches the characteristic time scale of the system dynamics. For the case of deterministic periodic driving, the first passage time probabili…
Destination Governance at Stake: Fostering Policy Coordination Among Decision-Makers of a Small Town
2018
This research aims to foster small-town decision-makers’ awareness of policy coordination as a central issue in either implementing collaborative governance and designing tourism development policies. To this end, a System Dynamics-based Interactive Learning Environment (ILE) has been designed with the intent of challenging decision-makers to increase tourism in the small town, while managing trade-offs among individualistic vs. collaborative behaviour. The action research took place in Castelbuono, a small tourism destination in Sicily (Italy). Three major decision-makers were involved: the mayor of the town, the museum’s director, and a restaurant owner. The use of the ILE has enabled dec…
Blending Collaborative Governance and Dynamic Performance Management to Foster Policy Coordination in Renewable Energy Supply Chains
2020
As the use of renewable energy is growing worldwide, the wind industry is being endorsed as a promising source for clean energy supply. In this context, the strategic management of the supply chain is fundamental to pursue a steady expansion of renewable energy. However, the fragmentation between energy policy design and implementation has been considered as a major cause threatening the effectiveness in managing the supply chain. This problem has been provoked mainly by an unsynchronized and uncoordinated decision-making process that involves public and private institutions. This chapter proposes the adoption of a dynamic performance management approach for enhancing a collaborative govern…