Push & Pull: autonomous deployment of mobile sensors for a complete coverage

Mobile sensor networks are important for several strategic applications devoted to monitoring critical areas. In such hostile scenarios, sensors cannot be deployed manually and are either sent from a safe location or dropped from an aircraft. Mobile devices permit a dynamic deployment reconfiguration that improves the coverage in terms of completeness and uniformity. In this paper we propose a distributed algorithm for the autonomous deployment of mobile sensors called Push&Pull. According to our proposal, movement decisions are made by each sensor on the basis of locally available information and do not require any prior knowledge of the operating conditions or any manual tuning of key parameters. We formally prove that, when a sufficient number of sensors are available, our approach guarantees a complete and uniform coverage. Furthermore, we demonstrate that the algorithm execution always terminates preventing movement oscillations. Numerous simulations show that our algorithm reaches a complete coverage within reasonable time with moderate energy consumption, even when the target area has irregular shapes. Performance comparisons between Push&Pull and one of the most acknowledged algorithms show how the former one can efficiently reach a more uniform and complete coverage under a wide range of working scenarios.Comment: Technical Report. This paper has been published on Wireless Networks, Springer. Animations and the complete code of the proposed algorithm are available for download at the address: http://www.dsi.uniroma1.it/~novella/mobile_sensors

Valutazione empirica dell'influenza della risposta sismica locale sul non sincronismo del moto in superficie

Le attività riassunte in questo contributo sono svolte nell’ambito del progetto di ricerca PRIN 2008: “Effetto del non sincronismo inclusa la risposta sismica locale sulla sicurezza dei ponti”, Linea 1 EQK. In tale ambito, gli Autori hanno analizzato gli effetti dell’asincronismo del moto sismico registrato da coppie di stazioni accelerometriche ubicate, a distanze dell’ordine delle centinaia di metri, su terreni con caratteristiche lito-stratigrafiche corrispondenti ad un sito di riferimento (sito R) e su sito con amplificazione stratigrafica (sito S) corrispondente nei diversi casi alle classi di sottosuolo B, C, D della Norme Tecniche per le Costruzioni (D.M. 14/1/2008). I risultati ottenuti da queste analisi preliminari mostrano che gli spostamenti differenziali valutati secondo le prescrizioni di normativa sono mediamente maggiori di quelli misurati sperimentalmente e che la formulazione analitica adottata dalla Norma è appropriata per descrivere la dipendenza di spostamenti relativi dall’accelerazione di riferimento

Rule-based Handling of Hazardous Nitrogen

A rule-based, recursive framework is an ideal approach to support the design of cropping systems (CS). A framework of this type was proposed, arranged into three stages (Silvestri and Bellocchi, 2007): (phase I) prior evaluation (technical, problem-solving, farmer-driven stage), (phase II) posterior evaluation (institutional, environmental monitoring implemented when CS response deviates from expected behaviour), and (phase III) managing the change (participatory, dynamic rearrangement of CS). This sequence is meant to evolve and grow over time through reiterations (Fig. 1), allowing for a continuous adaptation of agricultural productions systems as the business environment and society change. The same procedure was applied in this study to assess the behaviour of an array of CS run in the proximity of Lake Massaciuccoli - an area of Central Italy currently defined as “vulnerable area” under EU Directive 676/91 - as part of an action aimed at identifying possible responsibilities of farmers in NO3 contamination of waters (research developed in 2005-2006 under the Italian Ministry of Education, University and Research)

Simplified relationships for estimating seismic slope stability

Eurocode 8 addresses seismic slope stability analysis with reference to limit state design, specifying a 50% re-duction of the peak horizontal inertia force of a potentially sliding mass. Such a coefficient has been shown to depend on several factors, including soil deformability and the frequency content of the seismic action. In this paper the reduction coefficient is expressed with reference to the above factors and compared to EC8 provisions for all soil classes. A simplified design procedure is then suggested by referring to updated correla-tions based on the Newmark sliding block model, including the influence of amplitude, duration and mean pe-riod of the ground motion on the predicted displacement. The reduction coefficient is further generalised to account for the slope ductility, i.e. the capability of sustain prescribed threshold displacements. The whole procedure has been calibrated through analyses carried out using acceleration time histories, selected from a database of records of Italian seismic events, on typical subsoil layering pertaining to the EC8 classes, also adopted by the Italian seismic Code

Changing alignments in the Greek of southern Italy

Abstract This article investigates a peculiar pattern of subject case-marking in the Greek of southern Italy. Recent fieldwork with native speakers, coupled with the consultation of some written sources, reveals that, alongside prototypical nominative subjects, Italo-Greek also licenses accusative subjects, despite displaying a predominantly nominative-accusative alignment. Far from being random replacements within a highly attrited grammar, the distribution of these accusative subjects obeys specific structural principles, revealing similarities with historical attestations of the so-called “extended accusative” in early Indo-European. On the basis of these data, Italo-Greek is argued to be undergoing a progressive shift towards an active-stative alignment, a claim supported by additional evidence from auxiliary selection, adverb agreement and sentential word order.Leverhulme Trus

Differential Object Marking and the properties of D in the dialects of the extreme south of Italy

This paper discusses two case studies of microvariation in accusative marking in the Italo-Romance varieties of the extreme south of Italy. In particular, the diatopic variation displayed by the dialects of southern Calabria gives rise to peculiar patterns of alternation between presence or absence of the marker a ‘to’ in flagging the accusative. The realisation of accusative case is partially governed by semantic and referential features, i.e. specificity and animacy. In addition, the nature of the realisation of the D head results in a degree of competition between zero marking and analytic accusative marking with a. Given the century-long co-existence of Latin/Romance and Greek in southern Calabria, the relevant morphosyntactic patterns in Case-marking will also be examined from a language contact perspective. We will highlight how the relevant outcomes do not simply involve borrowing mechanisms or template copying from the lending variety but, rather, produce hybrid structures no longer ascribable to a purely Romance or Greek grammar.The Leverhulme Trust; Project Title: Fading voices in Southern Italy: investigating language contact in Magna Graecia; Research Project RPG-2015-28

An Indicator to Evaluate the Environmental Impact of Olive Oil Waste Water's Shedding on Cultivated Fields

Several climatic, soil and topographic factors need to be considered when evaluating the impact of human actions on the environment. Such variables may be related in a complex way to environmental impact, thus making its evaluation difficult. Problems of this type emerge when evaluating the risks olive oil waste water pose to the environment when shed on cultivated soils. This paper proposes a fuzzy expert system to calculate a modular indicator, ICARO, which allows an evaluation of the potential environmental impact of the application of olive oil waste water in a field. Five modules were formulated, one ("Waste water") reflecting the nature of the waste water, two ("Groundwater", "Surface water") reflecting the risk for the most sensitive agro-environmental compartments (groundwater, surface water), one ("Crop") reflecting possible consequences on the cropping system adopted, and one ("Soil") reflecting the soil aptitude to receive waste waters.The input variables are therefore waste water amount and properties, site-specific conditions, and characteristics of the application considered. For each input variable, two functions describing membership to the fuzzy subsets Favorable (F) and Unfavorable (U) have been defined. The expert system calculates the value of each module according to both the degree of membership of the input variables to the subsets F and U, and a set of decision rules. The five modules can be considered individually or can be aggregated (again according to level of membership to fuzzy subsets F and U and a set of decision rules) into the synthetic indicator ICARO. Outcomes of a sensitivity analysis are presented. The system is flexible and can be used as a decision aid tool to authorize waste water's shedding or subordinate the distribution on fields to acceptance of some limitations (amount, timing, site, etc)

A 22-Week-Old Fetus with Nager Syndrome and Congenital Diaphragmatic Hernia due to a Novel SF3B4 Mutation.

Nager syndrome, or acrofacial dysostosis type 1 (AFD1), is a rare multiple malformation syndrome characterized by hypoplasia of first and second branchial arches derivatives and appendicular anomalies with variable involvement of the radial/axial ray. In 2012, AFD1 has been associated with dominant mutations in SF3B4. We report a 22-week-old fetus with AFD1 associated with diaphragmatic hernia due to a previously unreported SF3B4 mutation (c.35-2A>G). Defective diaphragmatic development is a rare manifestation in AFD1 as it is described in only 2 previous cases, with molecular confirmation in 1 of them. Our molecular finding adds a novel pathogenic splicing variant to the SF3B4 mutational spectrum and contributes to defining its prenatal/fetal phenotype