71 research outputs found
WebGIS e indici sintetici per la rappresentazione e diffusione di dati funzionali all’emergenza nella città metropolitana di Napoli
No full textL’elevatissima densità demografica ed edilizia e la potenziale esplosività
del Vesuvio e dei Campi Flegrei rendono la Città Metropolitana di Napoli un contesto
altamente vulnerabile in termini di possibile perdita di vite umane e beni immobili per
eventi geodinamici. Vari modelli e applicazioni sono stati sviluppati per descrivere le
probabili modalità eruttive, funzionalmente alla messa a punto di apposite misure di
emergenza ed evacuazione preventiva. Notevole rilevanza riveste l’accorta valutazione degli aspetti sociali, economici e sanitari, in modo da tarare opportunamente le differenti
fasi della pianificazione strategica, prevedere alternative, non escludere il verificarsi di
fenomeni di rallentamento e accrescere la sensibilizzazione della popolazione.
A tal fine può essere inoltre importante costruire indici sintetici di supporto alla
pianificazione e diffondere e condividere specifiche informazioni in piattaforme online
interattive, mettendo al servizio degli enti locali e dei residenti strumenti in grado di creare
una conscia consapevolezza.
Questo lavoro si pone il duplice obiettivo di: combinare dati e variabili che,
opportunamente pesati ed elaborati, possano essere utilizzati per definire indici sintetici di
potenziale rallentamento; mostrare alcuni WebGIS prodotti per visualizzare e interrogare
le variabili confluite nell’indice sintetico di rallentamento (o di inerzia), e altri dati di
interesse socio-sanitario, che, qualora trascurati, potrebbero incidere negativamente sul
processo di evacuazione o amplificare le conseguenze dell’evento eruttivo
Cellular Automata and Random Field: Statistical Analysis of Complex Space-Time Systems
No full textIn the classical approach to the mathematical model specification, for space-time complex system, the usual framework is the Partial Difference-Differential Equations system (PDEs). This approach is very hard from a mathematical point of view, and the search for the (PDEs) solutions, almost in the practical applications, often it is impossible. Our approach is based, on the contrary, on Cellular Automata methodology in the framework of Random Field models. The statistical model building methodology for the Random Fields, is based on very simple statistical and probabilistic reasoning that utilize the concept of divisible distributions and logistic non-linear model. The interaction rules for the Cellular Automata mechanism, are built thorough inferential statistics and data analysis
Monitoring tropospheric ozone impact on plants in natural and urban areas with a Mediterranean climate
No full textTo investigate the real linkage and effectiveness of using the AOT40 index and ozone stomatal flux (FO3) in the assessment of physiological alteration/leaf injury on clover clones sensitive to ozone and Quercus ilex plants, two statistical techniques Partial Least Squares (PLS) and Neural Net Analysis (NNA)-were applied. Different results were obtained in relation to the statistical method chosen. Linear methodologies applied to clover highlighted the role of temperature (TEMP) and O-3 concentration (O(3)Mean) in affecting photosynthesis (PHOTO), leaf injury, and stomatal conductance (COND). In Quercus plants, COND was linearly correlated to two environmental variables, TEMP and Vapour Pressure Deficit (VPD), and to two physiological variables, PHOTO and Leaf Transpiration (TRASP), whereas PHOTO was correlated with TEMP, sO(3), COND and sub-stomatal CO2/external CO2 ratio (Ci/Ca). These linear relationships were, in part, modified by NNA. In fact, non-linear relationships between environmental variables, and morphological and physiological variables were evident, suggesting caution when risk assessments are made on ozone concentration-based critical levels. Both plant types showed a relationship with FO3 that negatively affected leaf injury and PHOTO in clover and Quercus plants, respectively, suggesting that ozone flux-based critical levels were more effective in linking with leaf injuries or reduction in carbon metabolism
Application of stochastic processes and the random field theory to the resolution of ecological systems from spatial and temporal point of view.
No full textIn this work we will develop approaches having the aim to bu9ild ecological models in the framework of mechanistic and statistical combined approach for spatial scaling and spatial/temporal modelling. The statistical and mathematical tools are stochastic processes and random field theory applied to the prediction and control of ecological systems
Is cellular automata algorithm able to predict the future dynamical shifts of tree species in Italy under climate change scenarios? A methodological approach
No full textIn this paper is presented a methodological approach which integrates statistic modelling and 2-D cellular automata (CA) in order to describe tree species shifts responding to the climate changes foreseen for Italy in the 21st century. Five Italian tree species populations of Abies alba, Pinus sylvestris, Fagus sylvatica, Acer campestris and Quercus sober and their actual potential distributions (PDs) - represented by Importance Value (IV), have been considered. Environmental and climatic relationships have been modelled through application of a new statistical methodology called extreme discretization, where the PD of a species was considered as a random field. The IV-based PD has been spatialized through a probability function pi(A,S), which represented the spatio-temporal relationships between IV values and climatic (A) and geomorphological (S) variables. For each tree species pi = (A,S) has been estimated and inserted as rule in the 2-D cellular automata. The latter, acting by a Moore neighbouring, took in consideration also the suitability map for tree species, which has been obtained by land cover map. Two time frames (2050 and 2080) and two climatic scenarios (A2 and B1) have been considered. Results described a general reduction of the IV values and their distribution for A. alba, P. sylvestris and F. sylvatica, in both climatic scenarios, whereas an increase of IVs and distribution for Q. suber and only a slight increment of distribution for A. campestris was mainly observed under the B1 scenario, but not for the more limiting A2 scenario. Convergent results have been obtained with respect to other simulation systems concerning the shift of tree species responding to different climatic change scenarios but lacking of the description of dynamical paths. Our approach seems natural and practical to describe such phenomena. The transition rules for the CA and the parameters taken into account for the construction of the probabilistic models can be surely improved to obtain a more realistic pattern of tree species shifts. Future efforts should be made to take in account the inter-specific relationships inside the Italian forest ecosystems, in order to also consider the competiveness for resources that exert some effects on the plant distribution both in time and space
Analisi spaziale della copertura vegetale in zone a differente grado di antropizzazione.
No full textStatistical analysis of ozone concentration: a forecasting and control model in urban areas
No full textOzone concentration in the urban areas of Rome is studied using statistical methods of multivariate and time series analysis. Data of two sites (a green park and a high motor traffic street) are evaluated and O3g concentration daily and seasonal trends are linked to other variables behaviours. Furthermore the relationship between the full set of pollution variables has analyse
Susceptibility of intrusion-related landslides at volcanic islands: the Stromboli case study
No full textSusceptibility of intrusion-related landslides in an active volcano was evaluated coupling the landslide susceptibility estimation by random forest (RF), and the probabilistic volcanic vent opening distribution, as proxy for magma injection, using the QVAST tool. In order to develop and test the method proposed here, the RF/QVAST approach was adopted for Stromboli volcano (Southern Italy) since it experienced moderate to huge instability events, it is geomorphologically prone to instability events, and it is affected by active intense volcanic activity that can produce slope instability. The main destabilizing factors of the volcanic flanks are the slope, the aspect, the terrain roughness, the land cover and the litho-technical features of the outcropping rocks. Estimation of volcanic susceptibility shows that the areas with high probability of new vent opening are located in the north-western unstable volcano flank (Sciara del Fuoco), in the volcano summit and the north-eastern volcano flank coherent with the possible re-activation of the eruptive fissures related to the regional tectonic setting. The areas with higher probability of intrusion-related landslides are located in the upper part of the Sciara del Fuoco, while the rest of the island show moderate to low probability of intrusion-related landslide occurrence. © 2017 The Author(s)This work has been financially partial supported by the "Presidenza del Consiglio dei Ministri – Dipartimento della Protezione Civile" (Presidency of the Council of Ministers-Department of Civil Protection) within the framework of the InGrID2015-2016 project; this publication, however, does not reflect the position and the official policies of the Department. Federico Di Traglia is supported by a post doc fellowship founded by the “Università di Firenze–Ente Cassa di Risparmio di Firenze” within the framework of the “Volcano Sentinel” project. This study was partially founded by the Seventh Framework Programme of European Commission: Landslide Modelling and Tools for vulnerability assessment preparedness and recovery management (LAMPRE; GA no: 312384). This research is partially funded by the European Commission (EC ECHO Grant SI2.695524: VeTOOLS).Peer reviewe
The importance of interspecific competition in the actual and future distributions of plant species assessed by a 2-D grid agent modelling
No full textCurrently, potential distribution of plant species is represented by different uses of presence/absence indicators or by density-dominance-based ones such as the Importance Value (I.V.), and their geographical representation is based on statistical models (Random forest model, General Regression Models etc.) relating these indicators with climate and physical features of a given territory. Here, we have built an integrated model which is able to link climate, physical features of territory and inter-specific competition at aiming to simulate potential distribution of eight plant species (Quercus cerris, Quercus pubescens, Fraxinus ornus, Fraxinus excelsior, Acer campestre, Acer obtusatum, Ostrya carpinifolia and Carpinus betulus) either at actual climate conditions or future ones (B1 and A2 climatic scenarios; IPCC, 2013). The integrated model is based on innovative methodological approach, which combined statistical tools (Principal Component Analyses and Discretization) and two-dimensional grid based model to consider the interactive effects of climate and inter-specific competition on plant species distribution. The study case was given by geographical spatialisation of the I.V. for each considered plant species, in the overall Italian territory. The simulations had always occurred by taking into consideration both expected climate change and inter-specific competition under highly complexity terrains. The results substantially differed from other studies that used only environmental predictors for estimating potential plant distributions. Variations in the I.V. distribution seemed to be due to variations of relative competitive abilities of plants, reducing both local extinctions of some species in Southern and Central Italy and migration toward North. Furthermore, our simulations suggested that under pressure of climate change the competitive ability of plant species will be likely affected by reducing the effects of competitive asymmetry
Ionizing radiation and stress: the analysis of the medical ray technician
No full textThe present study aims to analyzing the relation between the work-related distress with the exposition to ionizing radiations in the radiology technicians, in the hospital environment.
Materials and Methods
Our present study has been conducted on a group of 36 sanitary technicians (14 women and 22 man, with an average age of 48±10,1 years) working in the Hospital Radiology Pavilion; 28 of them were less-exposed to radio-active emissions (B Category) and 8 were more exposed to radio-active emissions (A Category). The HSE questionnaire has been administered to all the 36 sanitary technicians. The data analysis and statistical elaboration were conducted using the HSE Tools. After that, the non-parametric Mann-Whitney test was applied to the comparison of the medians of two independent samples.
Results
The HSE tools questionnaire’s analysis (made on the whole population) made evident some criticalities in the domains of the managerial support and of the professionals’ relationships: in the B Category group (less- exposed to radio-emissions) further criticalities emerged, in the domain of peer-support and in the change domain.
The HSE questionnaire analysis, made adopting the Mann-Whitney non-parametric statistical test, significant statistical differences emerged from 2 questions of the 35 sub-administered questions, regarding the mostly radio-exposed workers.
Conclusions
From the research analysis, the authors deducted the small relevance of the emerged criticalities for the two groups of workers; the researchers also believe that, given the (almost complete) homogeneity of the results emerging from the statistical analysis (done with the Mann Whitney test), the perception of the of the work-related distress risk is irrelevant to the dose of ionizing radio-expositio
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