Ground states in complex bodies

A unified framework for analyzing the existence of ground states in wide classes of elastic complex bodies is presented here. The approach makes use of classical semicontinuity results, Sobolev mappinngs and Cartesian currents. Weak diffeomorphisms are used to represent macroscopic deformations. Sobolev maps and Cartesian currents describe the inner substructure of the material elements. Balance equations for irregular minimizers are derived. A contribution to the debate about the role of the balance of configurational actions follows. After describing a list of possible applications of the general results collected here, a concrete discussion of the existence of ground states in thermodynamically stable quasicrystals is presented at the end.Comment: 30 pages, in print on ESAIM-COC

The convexity-cone approach to comparative risk and downside risk.

Based on Jewitt (1986) we try to find a characterization of comparative downside risk aversion and love. The desired characterizations involve the decomposition of the dual of the intersection of two convexity cones. The decomposition holds in the case of downside risk love, but not in the case of downside risk aversion. A counterexample is provided.Convexity cones; risk; downside risk; risk aversion; dual cones

Association between obstructive apnea syndrome during sleep and damages to anterior labyrinth: Our experience

The obstructive sleep apnea syndrome is a chronic condition characterized by frequent episodes of collapse of the upper airways during sleep. It can be considered a multisystem disease. Among the districts involved, even the auditory system was seen to be concerned. It was enrolled a population of 20 patients after polysomnographic diagnosis of OSAS (Apnea Hypopnea Index > 10) and a control group of 28 healthy persons (Apnea Hypopnea Index < 5). Each patient has been subjected to Pure Tone Audiometry, Tympanometry, study of Acoustic Reflex, Otoacoustic Emissions and Auditory Brainstem Response. Moreover they were submitted to endoscopy of upper airway with Muller Maneuver and Epworth Sleepiness Scale (ESS). The values of ESS was 13.5 in OSAS group and 5.4 in control group. The tone audiometry is worse in all frequencies analyzed in OSAS patients, but within the normal range for both groups analyzed by 250 to 1000 Hertz. Otoacoustic emissions show a reduced reproducibility and a lower signal/ noise ratio in OSAS group (P <0.01)

Towards Translating Graph Transformation Approaches by Model Transformations

Recently, many researchers are working on semantics preserving model transformation. In the field of graph transformation one can think of translating graph grammars written in one approach to a behaviourally equivalent graph grammar in another approach. In this paper we translate graph grammars developed with the GROOVE tool to AGG graph grammars by first investigating the set of core graph transformation concepts supported by both tools. Then, we define what it means for two graph grammars to be behaviourally equivalent, and for the regarded approaches we actually show how to handle different definitions of both - application conditions and graph structures. The translation itself is explained by means of intuitive examples

Progettazione, implementazione ed analisi di un gateway multi-radio per reti di sensori mesh 6LoWPAN

La tesi descrive la progettazione, l'implementazione e l'analisi di un gateway per una rete di sensori 6LoWPAN. Questo dispositivo riceve messaggi dalla rete di sensori contenenti le informazioni sull'ambiente monitorato. Dopo averle processate, il gateway le invia ad un broker MQTT. Grazie a ciò è possibile accedere da remoto alle informazioni sull'ambiente

Does the EU have homogeneous urban structure area? The role of agglomeration and the impact of shocks on urban structure

The urban structures between the Member States of the European Union is very different for historical, geographical, economic reasons. However, the population is spread across geographic areas in a way that, although continuously changing, is not possible to define as random. Indeed, countries have faced a strong tendency toward agglomeration, namely population gathers within proper areas like cities, and currently the agglomeration within cities "is an extremely complex amalgam of incentives and actions taken by millions of individuals, businesses, and organizations" Eeckhout (2004, p. 1429). Then, the creation of the European Union, the distortions caused by the introduction of a single currency in countries structurally so different and the expansion of mobility of people, capital and services due to the constitution of the so-called Schengen Area from the beginning of '90s might have had some impacts on the dynamics of city populations. This paper provides a study of the hierarchical structure of the cities within the EU Member States with particular attention on agglomeration forces by means of two very well-known empirical regularities: Zipf's law, as a proxy for agglomeration forces, and Gibrat's law as a test for stationarity. Indeed, the Zipf coefficient can be seen as a measure of urbanization: the larger the value of the coefficient, the more even the population of cities in the urban system. There are several potential explanations for variations in its value, one of these can be found in a model of economic geography a la Krugman (1991) and Fujita et al. (1999). These models can be viewed as models of unevenness in the distribution of economic activity and moreover, they state that for certain parameter values, economic activity is agglomerated, while for other parameter values, economic activity is dispersed (i.e. a city system will be more agglomerated the greater are scale economies, the lower are transport costs and the lower the share of international trade in the economy) By means of parametric and non-parametric analysis the main conclusions of this paper are the following: the hierarchical structures of Member States is more even than expected. Moreover, the European Union seems to be split in three distinct areas: an area characterized by the validity of Gibrat's law (temporary idiosyncratic shocks might have permanent impacts on the city structure); an area characterized by the presence of mean reversion (any exogenous shock is used up in certain amount of time); a small area where the effects of the shocks is magnified in the big cities. Finally, we find that only the constitution of the Schengen Area and the share of international trade seem to have a weak impact on the hierarchical structures of Member States