Alien Registration- Rutherford, Brida M J. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/21872/thumbnail.jp

Tourism's Impact on Long-Run Mexican Economic Growth

Tourism is one of the most important factors in the productivity of Mexican economy with significant multiplier effects on economic activity. This paper investigates possible causal relationships among tourism expenditure, real exchange rate and economic growth by using quarterly data. Johansen cointegration analysis shows the existence of one cointegrated vector among real GDP, tourism expenditure and real exchange rate where the corresponding elasticities are positive. The tourism-led growth hypothesis is confirmed through cointegration and causality testing. Tourism expenditure and Real Exchange Rate (RER) are weakly exogenous to real GDP. A modified version of the Granger Causality test shows that causality goes unidirectionally from tourism expenditure and RER to real GDP. Impulse response analysis shows that a shock in tourism expenditure produces a short fall and then a positive effect on growth.economic growth Johansen cointegration test Granger causality tourism-led growth hypothesis.

Generation of different Bell states within the SPDC phase-matching bandwidth

We study the frequency-angular lineshape for a phase-matched nonlinear process producing entangled states and show that there is a continuous variety of maximally-entangled states generated for different mismatch values within the natural bandwidth. Detailed considerations are made for two specific methods of polarization entanglement preparation, based on type-II spontaneous parametric down-conversion (SPDC) and on SPDC in two subsequent type-I crystals producing orthogonally polarized photon pairs. It turns out that different Bell states are produced at the center of the SPDC line and on its slopes, corresponding to about half-maximum intensity level. These Bell states can be filtered out by either frequency selection or angular selection, or both. Our theoretical calculations are confirmed by a series of experiments, performed for the two above-mentioned schemes of producing polarization-entangled photon pairs and with two kinds of measurements: frequency-selective and angular-selective.Comment: submitted for publicatio

Investigation of new methods for numerical stochastic perturbation theory in φ4 theory

Numerical stochastic perturbation theory is a powerful tool for estimating high-order perturbative expansions in lattice field theory. The standard algorithms based on the Langevin equation, however, suffer from several limitations which in practice restrict the potential of this technique. In this work we investigate some alternative methods which could in principle improve on the standard approach. In particular, we present a study of the recently proposed Instantaneous Stochastic Perturbation Theory, as well as a formulation of numerical stochastic perturbation theory based on Generalized Hybrid Molecular Dynamics algorithms. The viability of these methods is investigated in $\varphi^4$ theory.Comment: 45 pages, 12 figures. Added new section on cost comparison with Langevin NSPT. Matches published versio

Geometric Algorithm for Received Signal Strength Based Mobile Positioning

Mobile positioning is one of the fastest growing areas for the development of new technologies, services and applications. This paper describes a simple and efficient geometric algorithm using received signal strength measurements extracted from at least three base stations. This method is compared with standard Least Squares method. The simulation results show, that geometric algorithm gives more accurately location estimation than LS algorithm in multipath propagation

A biphotons double slit experiment

In this paper we present a double slit experiment where two undistinguishable photons produced by type I PDC are sent each to a well defined slit. Data about the diffraction and interference patterns for coincidences are presented and discussed. An analysis of these data allows a first test of standard quantum mechanics against de Broglie-Bohm theory

Review of recent experimental progresses in Foundations of Quantum Mechanics and Quantum Information obtained in Parametric Down Conversion Experiments at IENGF

We review some recent experimental progresses concerning Foundations of Quantum Mechanics and Quantum Information obtained in Quantum Optics Laboratory "Carlo Novero" at IENGF. More in details, after a short presentation of our polarization entangled photons source (based on precise superposition of two Type I PDC emission) and of the results obtained with it, we describe an innovative double slit experiment where two degenerate photons produced by PDC are sent each to a specific slit. Beyond representing an interesting example of relation between visibility of interference and "welcher weg" knowledge, this configuration has been suggested for testing de Broglie-Bohm theory against Standard Quantum Mechanics. Our results perfectly fit SQM results, but disagree with dBB predictions. Then, we discuss a recent experiment addressed to clarify the issue of which wave-particle observables are really to be considered when discussing wave particle duality. This experiments realises the Agarwal et al. theoretical proposal, overcoming limitations of a former experiment. Finally, we hint to the realization of a high-intensity high-spectral-selected PDC source to be used for quantum information studies

First experimental test of Bell inequalities performed using a non-maximally entangled state

We report on the realisation of a new test of Bell inequalities using the superposition of type I parametric down conversion produced in two different non-linear crystals pumped by the same laser, but with different polarisation. The produced state is non-maximally entangled. We discuss the advantages and the possible developments of this configuration

Demanda por servicios turísticos: análisis de su evolución en un modelo autoorganizado

The dynamics of tourists and guests can be modeled in a varied of ways and, in most of this models tourist destinations behave as dynamic evolving complex systems. In this paper we represent an economic problem in which the affluence of tourists to a specific place depends on the "state" of the place (infrastructure, maintenance, ambiance’s conditions, etc) that in turn depends on the individuals decisions on these parameters, that are influenced by the behaviour of the other agents. We introduce a model of the interactions between natural resources, residents, tourists and authorities in the self-organized kind of evolution of a tourist destination. The model, starting up from simple components can produce very complex behaviours. Because of the complexity of the model a computational analysis is required. We show that the model can reproduce several meaningful situations. Depending on the levels of the system parameters we can detect the possibility of mass tourism (and a negative crowding effect on environment) or sustainable management of the destination. We show that when preferences of tourists and/or residents induce the depredation of the natural resources and disdain for the environmental quality of the region, the authorities cannot reverse the negative behaviour of the agents by investing on preservation; they have to punish non cooperative agents. The model also shows that, when all the participants are cooperative, the environmental quality improves and tourism demand increases, inducing, in turn an increase in welfare.La dinámica de turistas y residentes se puede modelar en diversas maneras y, en la mayoría de tales modelaciones los destinos turísticos se comportan como sistemas complejos de desarrollo dinámico. En este trabajo representamos un modelo donde la afluencia de turistas a un lugar especifico depende del "estado" del lugar (infraestructura, mantenimiento, condiciones ambientales etc.) que a su vez depende de las decisiones conductuales individuales, influenciados por al conducta de los demás agentes. Introducimos un modelo autoorganizado para representar la interacción entre recursos naturales, residentes, turistas y autoridades locales para analizar la evolución de un destino turístico. Debido a la complejidad del modelo utilizamos análisis computacional. Dependiendo de los niveles de los parámetros del sistema podemos detectar la posibilidad de un turismo de masas (y de un efecto de congestión que es negativo hacia el medioambiente) o la sustentabilidad de la destinación. Mostramos que cuando las preferencias de los turistas y/o de residentes inducen la depredación de los recursos naturales, las autoridades locales no pueden revertir el daño causado invirtiendo en preservación; por lo que se deben intentar cambiar el tipo depredador de los agentes. El modelo también muestra que, cuando todos los participantes son cooperativos o pro-ambientalistas la calidad ambiental mejora y la demanda turística aumenta en forma sostenible, induciendo, alternadamente un aumento en el bienestar social de la región

Photostatistics Reconstruction via Loop Detector Signatures

Photon-number resolving detectors are a fundamental building-block of optical quantum information processing protocols. A loop detector, combined with appropriate statistical processing, can be used to convert a binary on/off photon counter into a photon-number-resolving detector. Here we describe the idea of a signature of photon-counts, which may be used to more robustly reconstruct the photon number distribution of a quantum state. The methodology is applied experimentally in a 9-port loop detector operating at a telecommunications wavelength and compared directly to the approach whereby only the number of photon-counts is used to reconstruct the input distribution. The signature approach is shown to be more robust against calibration errors, exhibit reduced statistical uncertainty, and reduced reliance on a-priori assumptions about the input state.Comment: 13 pages, 12 figure