3,293 research outputs found
A stochastic approach for quantifying immigrant integration: the Spanish test case
We apply stochastic process theory to the analysis of immigrant integration.
Using a unique and detailed data set from Spain, we study the relationship
between local immigrant density and two social and two economic immigration
quantifiers for the period 1999-2010. As opposed to the classic time-series
approach, by letting immigrant density play the role of "time", and the
quantifier the role of "space" it become possible to analyze the behavior of
the quantifiers by means of continuous time random walks. Two classes of
results are obtained. First we show that social integration quantifiers evolve
following pure diffusion law, while the evolution of economic quantifiers
exhibit ballistic dynamics. Second we make predictions of best and worst case
scenarios taking into account large local fluctuations. Our stochastic process
approach to integration lends itself to interesting forecasting scenarios
which, in the hands of policy makers, have the potential to improve political
responses to integration problems. For instance, estimating the standard
first-passage time and maximum-span walk reveals local differences in
integration performance for different immigration scenarios. Thus, by
recognizing the importance of local fluctuations around national means, this
research constitutes an important tool to assess the impact of immigration
phenomena on municipal budgets and to set up solid multi-ethnic plans at the
municipal level as immigration pressure build
Quantifying Transient Spreading Dynamics on Networks
Spreading phenomena on networks are essential for the collective dynamics of
various natural and technological systems, from information spreading in gene
regulatory networks to neural circuits or from epidemics to supply networks
experiencing perturbations. Still, how local disturbances spread across
networks is not yet quantitatively understood. Here we analyze generic
spreading dynamics in deterministic network dynamical systems close to a given
operating point. Standard dynamical systems' theory does not explicitly provide
measures for arrival times and amplitudes of a transient, spreading signal
because it focuses on invariant sets, invariant measures and other quantities
less relevant for transient behavior. We here change the perspective and
introduce effective expectation values for deterministic dynamics to work out a
theory explicitly quantifying when and how strongly a perturbation initiated at
one unit of a network impacts any other. The theory provides explicit timing
and amplitude information as a function of the relative position of initially
perturbed and responding unit as well as on the entire network topology.Comment: 9 pages and 4 figures main manuscript 9 pages and 3 figures appendi
The Role of Existential Quantification in Scientific Realism
Scientific realism holds that the terms in our scientific theories refer and that we should believe in their existence. This presupposes a certain understanding of quantification, namely that it is ontologically committing, which I challenge in this paper. I argue that the ontological loading of the quantifiers is smuggled in through restricting the domains of quantification, without which it is clear to see that quantifiers are ontologically neutral. Once we remove domain restrictions, domains of quantification can include non-existent things, as they do in scientific theorizing. Scientific realism would therefore require redefining without presupposing a view of ontologically committing quantification
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