arXiv subjects

S. Nicolosi

Publications and source records attributed to S. Nicolosi.

6 recordsLinked to original sources

arXiv2017

A Phenomenological Environmental Traffic Model Part 1: Fuzzy Logic Validatation

In this first paper of a series of two we are going to show that, on the ground of few reasonable hypotheses, an equation linking the number of vehicle N($τ_i$), that run from (i-1)-th to the i-th hour, to the ground-level hourly average measured values of an arbitrary pollutant concentration, $C(τ_i,z=0)=C(τ_i)$, can be established. The traffic environmental model so generated is validated via a fuzzy logig approach. In a second paper we will valitadeted and calibrated it via a manual counting of traffic fluxes and its provisional capability will be tessted

physics.soc-ph↗

arXiv2016

Quantum Computation in a radio single mode cavity: the dissipative Jaynes and Cummings Model

In this paper we have considered the interaction of a Jaynes and Cummings system with the electromagnetic field in its vacuum state and, solving the dynamical problem, we have analyzed the amount of entanglement induced in the bipartite system (atom + cavity mode) by the common electromagnetic reservoir. This has allowed us to quantitatively characterize the regime under which field-induced cooperative effects are not vanished by dissipation. Once the Decoherence Free Regime is reached, transient entanglement tends to become stationary and, therefore, usable for quantum gate implementation.

quant-ph↗

arXiv2011

Obtaining Traffic Information by Urban Air Quality Inspection

The level of air quality in urban centres is affected by emission of several pollutants, mainly coming from the vehicles flowing in their road networks. This is a well known phenomenon that influences the quality of life of people. Despite the deep concern of researchers and technicians, we are far from a total understanding of this phenomenon. On the contrary, the availability of reliable forecasting models would constitute an important tool for administrators in order of assessing suitable actions concerning the transportation policies, public as well private. Referring to the situation of the running fleet and the measured pollutant concentrations concerning the Italian town of Palermo, a data-deduced traffic model is here derived, its truthfulness being justified by a fuzzyfication of the phenomenon. A first validation of the model is supplied by utilising the emissions characteristics and the pollutant concentrations referring to a two years period of time. This work could represent a first attempt in defining a new approach to the problem of the pollution of the urban contexts, in order of providing administrators with a reliable and easier tool.

physics.flu-dyn↗

arXiv2005

An Operator-Based Exact Treatment of Open Quantum Systems

"Quantum mechanics must be regarded as open systems. On one hand, this is due to the fact that, like in classical physics, any realistic system is subjected to a coupling to an uncontrollable environment which influences it in a non-negligible way. The theory of open quantum systems thus plays a major role in many applications of quantum physics since perfect isolation of quantum system is not possible and since a complete microscopic description or control of the environment degrees of freedom is not feasible or only partially so" [1]. Practical considerations therefore force one to seek for a simpler, effectively probabilistic description in terms of an open system. There is a close physical and mathematical connection between the evolution of an open system, the state changes induced by quantum measurements, and the classical notion of a stochastic process. The paper provides a bibliographic review of this interrelations, it shows the mathematical equivalence between markovian master equation and generalized piecewise deterministic processes [1] and it introduces the open system in an open observed environment model.

quant-ph↗

arXiv2004

Loss induced collective subradiant Dicke behaviour in a multiatom sample

The exact dynamics of $N$ two-level atoms coupled to a common electromagnetic bath and closely located inside a lossy cavity is reported. Stationary radiation trapping effects are found and very transparently interpreted in the context of our approach. We prove that initially injecting one excitation only in the $N$ atoms-cavity system, loss mechanisms asymptotically drive the matter sample toward a long-lived collective subradiant Dicke state. The role played by the closeness of the $N$ atoms with respect to such a cooperative behavior is brought to light and carefully discussed.

quant-ph↗

arXiv2004

Stationary entanglement induced by dissipation

The dynamics of two two-level dipole-dipole interacting atoms coupled to a common electromagnetic bath and closely located inside a lossy cavity, is reported. Initially injecting only one excitation in the two atoms-cavity system, loss mechanisms asymptotically drive the matter sample toward a stationary maximally entangled state. The role played by the closeness of the two atoms with respect to such a cooperative behaviour is carefully discussed. Stationary radiation trapping effects are found and transparently interpreted.

quant-ph↗