The Religion of Beauty and the Veil of the Graces

Le Grazie, carme materialmente incompiuto, viene qui inteso come un testo organico e compiuto da una prospettiva mitico-simbolica. Si sottolinea come Foscolo intenda il testo poetico come luogo d’origine del bello sensibile. Assolto il testo delle Grazie da ogni forma di decorativismo, l’autore interpreta il carme come fonte di una religione poetica tesa alla rinascita spirituale, culturale e politica dell’Italia. Se nei Sepolcri si celebra il passaggio dalla barbarie alla civiltà, nelle Grazie il mito dell’eros sublimato si manifesta come moderna configurazione della poesia elevata, custode di quella antica

Power, discursive space and institutional practices in the construction of housing problems

A constructionist approach to the study of social problems and housing policy provides a theoretically informed means of analysing the ways in which housing policy is formulated and implemented. Yet despite a strong commitment by housing researchers to policy-relevance, constructionist studies of how specific social problems are generated and deployed have so far made only a limited impact on housing research. The paper addresses this lacuna by first discussing important literature and the key conceptual issues in this field of study. This is followed by a discussion of two examples from recent UK housing policy (the shift in the 1980s from defining lone mothers as the victims of housing shortages to a morally questionable group subverting needs based allocation policies and the re-emergence of anti-social behaviour as a problem on housing estates). The paper's conclusion is that the 'construction of problems' provides a rich source of new material as well as offering significant opportunities to develop a more critically informed housing research agenda

Privileged or exploited council tenants?: The discursive change in Conservative housing policy from 1972 to 1980

The process of social construction in which competing and sometimes contradictory definitions contend with one another plays a decisive part in policy making. Justifications for policy intervention often require a narrative identifying villains or victims to delineate creatively a 'social problem' that needs to be addressed by appropriate measures. This article shows how contrasting political and media representations of council tenants in the 1960s and 1970s provided the emotive justifications for two distinct policies: 'Fair Rents' and the 'Right to Buy'. The article concludes that more attention should be paid to the way that the successful mobilisation of bias legitimises policy interventions

Zero-Reachability in Probabilistic Multi-Counter Automata

We study the qualitative and quantitative zero-reachability problem in probabilistic multi-counter systems. We identify the undecidable variants of the problems, and then we concentrate on the remaining two cases. In the first case, when we are interested in the probability of all runs that visit zero in some counter, we show that the qualitative zero-reachability is decidable in time which is polynomial in the size of a given pMC and doubly exponential in the number of counters. Further, we show that the probability of all zero-reaching runs can be effectively approximated up to an arbitrarily small given error epsilon > 0 in time which is polynomial in log(epsilon), exponential in the size of a given pMC, and doubly exponential in the number of counters. In the second case, we are interested in the probability of all runs that visit zero in some counter different from the last counter. Here we show that the qualitative zero-reachability is decidable and SquareRootSum-hard, and the probability of all zero-reaching runs can be effectively approximated up to an arbitrarily small given error epsilon > 0 (these result applies to pMC satisfying a suitable technical condition that can be verified in polynomial time). The proof techniques invented in the second case allow to construct counterexamples for some classical results about ergodicity in stochastic Petri nets.Comment: 20 page

Tableaux for Policy Synthesis for MDPs with PCTL* Constraints

Markov decision processes (MDPs) are the standard formalism for modelling sequential decision making in stochastic environments. Policy synthesis addresses the problem of how to control or limit the decisions an agent makes so that a given specification is met. In this paper we consider PCTL*, the probabilistic counterpart of CTL*, as the specification language. Because in general the policy synthesis problem for PCTL* is undecidable, we restrict to policies whose execution history memory is finitely bounded a priori. Surprisingly, no algorithm for policy synthesis for this natural and expressive framework has been developed so far. We close this gap and describe a tableau-based algorithm that, given an MDP and a PCTL* specification, derives in a non-deterministic way a system of (possibly nonlinear) equalities and inequalities. The solutions of this system, if any, describe the desired (stochastic) policies. Our main result in this paper is the correctness of our method, i.e., soundness, completeness and termination.Comment: This is a long version of a conference paper published at TABLEAUX 2017. It contains proofs of the main results and fixes a bug. See the footnote on page 1 for detail

Cities, immigrant diversity, and complex problem solving

Recent evidence suggests that greater immigrant diversity in cities and workplaces makes workers more productive. However, even the most careful extant empirical work remains at some remove from the main mechanisms that theory says underlie this relationship: interpersonal interaction in the service of complex problem solving. This paper aims to 'stress-test' these theoretical foundations, by observing how the relationship between diversity and productivity varies across workers differently engaged in complex problem solving and interaction. Using a uniquely comprehensive matched employer-employee dataset for the United States starting as early as 1991 and continuing to 2008, this paper shows that growing immigrant diversity in cities and workplaces is related to higher wages for workers intensively engaged in various forms of complex problem solving, including tasks involving high levels of innovation, creativity, and STEM. Mixed evidence is found for the theory that benefits are concentrated among those whose work require problem solving as well as high levels of interpersonal interaction

Quantitative multi-objective verification for probabilistic systems

We present a verification framework for analysing multiple quantitative objectives of systems that exhibit both nondeterministic and stochastic behaviour. These systems are modelled as probabilistic automata, enriched with cost or reward structures that capture, for example, energy usage or performance metrics. Quantitative properties of these models are expressed in a specification language that incorporates probabilistic safety and liveness properties, expected total cost or reward, and supports multiple objectives of these types. We propose and implement an efficient verification framework for such properties and then present two distinct applications of it: firstly, controller synthesis subject to multiple quantitative objectives; and, secondly, quantitative compositional verification. The practical applicability of both approaches is illustrated with experimental results from several large case studies

A point process framework for modeling electrical stimulation of the auditory nerve

Model-based studies of auditory nerve responses to electrical stimulation can provide insight into the functioning of cochlear implants. Ideally, these studies can identify limitations in sound processing strategies and lead to improved methods for providing sound information to cochlear implant users. To accomplish this, models must accurately describe auditory nerve spiking while avoiding excessive complexity that would preclude large-scale simulations of populations of auditory nerve fibers and obscure insight into the mechanisms that influence neural encoding of sound information. In this spirit, we develop a point process model of the auditory nerve that provides a compact and accurate description of neural responses to electric stimulation. Inspired by the framework of generalized linear models, the proposed model consists of a cascade of linear and nonlinear stages. We show how each of these stages can be associated with biophysical mechanisms and related to models of neuronal dynamics. Moreover, we derive a semi-analytical procedure that uniquely determines each parameter in the model on the basis of fundamental statistics from recordings of single fiber responses to electric stimulation, including threshold, relative spread, jitter, and chronaxie. The model also accounts for refractory and summation effects that influence the responses of auditory nerve fibers to high pulse rate stimulation. Throughout, we compare model predictions to published physiological data and explain differences in auditory nerve responses to high and low pulse rate stimulation. We close by performing an ideal observer analysis of simulated spike trains in response to sinusoidally amplitude modulated stimuli and find that carrier pulse rate does not affect modulation detection thresholds.Comment: 1 title page, 27 manuscript pages, 14 figures, 1 table, 1 appendi