149 research outputs found

    Arab-norman heritage: state of knowledge and new actions and innovative proposal

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    This paper wants to offers a perlustrative recognition on the 'state of the studies', concerning to the Arab-Norman architecture of Palermo, admissed by Unesco in 2015 and explain a research in progress which, starting from re-cognition of the peculiarities of the restoration work carried out on it, consisting of the identification of authentic material-constructive values and / or reconstruction, it orients itself to develop a concrete proposal of filing for a more conscious knowledge. She, moreover, want\u2019s contribute to real enhancement through the use of targeted communication strategies that use innovative means capable, on one hand, to attracting the greatest possible number of users, on the other hand, to plan further interventions of conservation coherent with the previous data. The product that you want to achieve is that of a Bank-data that allows the "networking" of monumental emergencies, that become the virtual itineraries waypoint, which can be implemented periodically and whose boards meet the cataloging needs and documentation but with reference at georeferiti-systems, compatibles with the conservation and management of heritage and with need of usability, real and virtual

    RAPID PROTOTYPING FOR THE EXTENSION OF THE ACCESSIBILITY TO CULTURAL HERITAGE FOR BLIND PEOPLE

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    Abstract. The extension of accessibility of CH to disabled people is a current topic of great importance. Today, there exist a lot of ongoing projects aimed at the extension of accessibility using the most recent and low cost technologies to improve accessibility to CH. One of the technologies, today available that can help to improve accessibility to CH, is certainly rapid prototyping. The main goal of the research here illustrated is the application of rapid prototyping for the extension of accessibility of Cultural Heritage (CH) to blind and visually impaired people. This document reports an experiment that compared the effectiveness of different 3D models for the introduction of blind and visually impaired people to the tactile use of models of monuments. In addition, this study focuses on defining standards and guidelines regarding features of 3D models, e.g. print resolution, in order to obtain greater legibility of models at different scales by the blind or visually impaired people. This paper shows a part of a wider Interreg EU research project, named I-ACCESS, aimed to study accessibility problems and solutions for CH. The experiments conducted with the sample of disabled people, allowed to obtain results on the most suitable printing parameters to be used.</p

    Extension of tumor fingers: A comparison between an individual-cell based model and a measure theoretic approach

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    The invasive capability is fundamental in determining the malignancy of a solid tumor. In particular, tumor invasion fronts are characterized by different morphologies, which result both from cell-based processes (such as cell elasticity, adhesive properties and motility) and from subcellular molecular dynamics (such as growth factor internalization, ECM protein digestion and MMP secretion). Of particular relevance is the development of tumors with unstable fingered morphologies: they are in fact more aggressive and hard to be treated than smoother ones as, even if their invasive depth is limited, they are diffcult to be surgically removed. The phenomenon of malignant fingering has been reproduced with several mathematical approaches. In this respect, we here present a qualitative comparison between the results obtained by an individual cell-based model (an extended version of the cellular Potts model) and by a measure-based theoretic method. In particular, we show that in both cases a fundamental role in nger extension is played by intercellular adhesive forces and taxis-like migration

    Un WEBGIS Open Source a supporto dei rilievi GPS in Sicilia

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    Con il rapido sviluppo di Internet, degli ultimi anni, i sistemi informativi geografici basati sull’utilizzo del Web sono diventati un argomento di forte interesse per il settore dei GIS. Il WEBGIS è uno strumento software, basato su sistemi di reti locali o geografiche e su un’interfaccia semplificata operante tramite browser Internet, che permette l’accesso a banche dati geografiche, anche a persone non esperte del settore. Tramite tale strumento è possibile visualizzare contestualmente informazioni geografiche organizzate su livelli informativi tematici, anche caratterizzati da diverso sistema di riferimento geografico ed eseguire, tramite un’interfaccia Web semplificata, parte delle operazioni che normalmente vengono eseguite con software GIS per desktopworkstation. Un WEBGIS permette quindi in modo efficiente ed a costi contenuti la condivisione di informazioni geografiche ad un più vasto pubblico non necessariamente limitato ai soli addetti ai lavori. I campi applicativi dei WEBGIS sono molteplici ed ancor più numerosi di quelli dei GIS (non dimenticando che dietro un WEBGIS c’è sempre un GIS messo a punto da esperti del settore). Di interesse è anche quello del rilievo tramite strumenti di posizionamento globale (GNSS); il WEBGIS, infatti, può anche essere un utile strumento a supporto dei rilievi condotti o da effettuarsi con ricevitori GNSS, permettendo la fornitura di informazioni utili per le fasi preliminari al rilievo (copertura rete telefonica, collegamento internet, monografie dei punti) e/o successive ad esso (download dati necessari al post processing, monografie stazioni permanenti e coordinate aggiornate). Sulla base di tali istanze e dell’esistenza di una rete di stazioni permanenti, a copertura della Sicilia occidentale, realizzata dal 2005 al 2007 per fini non soltanto scientifici, ma anche tecnici, presso il Dipartimento di Rappresentazione dell’Università di Palermo (oggi Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, DICA) si è ritenuta di interesse la realizzazione di uno strumento software (WEBGIS), tale da permettere la gestione della grande mole di dati geografici, giornalmente acquisiti, in modo da supportare ricercatori e tecnici durante le operazioni preliminari al rilievo ed al post-processing dei dati rilevati

    MAIN FEATURES OF A 3D GIS FOR A MONUMENTAL COMPLEX WITH AN HISTORICAL-CULTURAL RELEVANCE

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    The last achievements of technologies in geomatics especially in survey and restitution of 3D models (UAV/drones and laser scanner technologies) generated new procedures and higher standards of quality in representation of archaeological sites. Together with Geomatics, the recent development of Information and Communication Technologies (ICT) strongly contribute to document and the Cultural Heritage (CH). The representation and documentation of CH using these new technologies has became necessary in order to satisfy different needs: &amp;ndash; for restorers in order to acquire a deep knowledge of the cultural good and to define possible strategies of restoration; &amp;ndash; for the conservation of information, allowing to preserve the 3D geometry of the monumental complex with the integration of descriptions about architectural elements; &amp;ndash; for touristic aims, giving the opportunity of sharing CH information on web, allowing users to visit and explore, in a virtual way, monumental complexes, acquiring information details about architectural elements or the history of monumental complex. Looking through these new scenarios, the development of a 3D Geographic Information System (GIS) applied to a cultural good could be, today, an added value of fundamental importance for full description and data management of monumental complexes. In this work, the main features necessary for the correct construction of a 3D GIS of a monumental complex will be analyzed, with a particular focus on the possibilities for creating a standardized procedure to follow

    Adhesion and volume constraints via nonlocal interactions determine cell organisation and migration profiles

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    The description of the cell spatial pattern and characteristic distances is fundamental in a wide range of physio-pathological biological phenomena, from morphogenesis to cancer growth. Discrete particle models are widely used in this field, since they are focused on the cell-level of abstraction and are able to preserve the identity of single individuals reproducing their behavior. In particular, a fundamental role in determining the usefulness and the realism of a particle mathematical approach is played by the choice of the intercellular pairwise interaction kernel and by the estimate of its parameters. The aim of the paper is to demonstrate how the concept of H-stability, deriving from statistical mechanics, can have important implications in this respect. For any given interaction kernel, it in fact allows to a priori predict the regions of the free parameter space that result in stable configurations of the system characterized by a finite and strictly positive minimal interparticle distance, which is fundamental when dealing with biological phenomena. The proposed analytical arguments are indeed able to restrict the range of possible variations of selected model coefficients, whose exact estimate however requires further investigations (e.g., fitting with empirical data), as illustrated in this paper by series of representative simulations dealing with cell colony reorganization, sorting phenomena and zebrafish embryonic development

    Collective migration and patterning during early development of zebrafish posterior lateral line

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    The morphogenesis of zebrafish posterior lateral line (PLL) is a good predictive model largely used in biology to study cell coordinated reorganization and collective migration regulating pathologies and human embryonic processes. PLL development involves the formation of a placode formed by epithelial cells with mesenchymal characteristics which migrates within the animal myoseptum while cyclically assembling and depositing rosette-like clusters (progenitors of neuromast structures). The overall process mainly relies on the activity of specific diffusive chemicals, which trigger collective directional migration and patterning. Cell proliferation and cascade of phenotypic transitions play a fundamental role as well. The investigation on the mechanisms regulating such a complex morphogenesis has become a research topic, in the last decades, also for the mathematical community. In this respect, we present a multiscale hybrid model integrating a discrete approach for the cellular level and a continuous description for the molecular scale. The resulting numerical simulations are then able to reproduce both the evolution of wild-type (i.e. normal) embryos and the pathological behaviour resulting form experimental manipulations involving laser ablation. A qualitative analysis of the dependence of these model outcomes from cell-cell mutual interactions, cell chemical sensitivity and internalization rates is included. The aim is first to validate the model, as well as the estimated parameter values, and then to predict what happens in situations not tested yet experimentally. This article is part of the theme issue 'Multi-scale analysis and modelling of collective migration in biological systems'

    A discrete particle model reproducing collective dynamics of a bee swarm

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    In this article, we present a microscopic discrete mathematical model describing collective dynamics of a bee swarm. More specifically, each bee is set to move according to individual strategies and social interactions, the former involving the desire to reach a target destination, the latter accounting for repulsive/attractive stimuli and for alignment processes. The insects tend in fact to remain sufficiently close to the rest of the population, while avoiding collisions, and they are able to track and synchronize their movement to the flight of a given set of neighbors within their visual field. The resulting collective behavior of the bee cloud therefore emerges from non-local short/long-range interactions. Differently from similar approaches present in the literature, we here test different alignment mechanisms (i.e., based either on an Euclidean or on a topological neighborhood metric), which have an impact also on the other social components characterizing insect behavior. A series of numerical realizations then shows the phenomenology of the swarm (in terms of pattern configuration, collective productive movement, and flight synchronization) in different regions of the space of free model parameters (i.e., strength of attractive/repulsive forces, extension of the interaction regions). In this respect, constraints in the possible variations of such coefficients are here given both by reasonable empirical observations and by analytical results on some stability characteristics of the defined pairwise interaction kernels, which have to assure a realistic crystalline configuration of the swarm. An analysis of the effect of unconscious random fluctuations of bee dynamics is also provided
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