An application of integrated 3D technologies for replicas in cultural heritage

In recent decades, 3D acquisition by laser scanning or digital photogrammetry has become one of the standard methods of documenting cultural heritage, because it permits one to analyze the shape, geometry, and location of any artefact without necessarily coming into contact with it. The recording of three-dimensional metrical data of an asset allows one to preserve and monitor, but also to understand and explain the history and cultural heritage shared. In essence, it constitutes a digital archive of the state of an artefact, which can be used for various purposes, be remodeled, or kept safely stored. With the introduction of 3D printing, digital data can once again take on material form and become physical objects from the corresponding mathematical models in a relatively short time and often at low cost. This possibility has led to a different consideration of the concept of virtual data, no longer necessarily linked to simple visual fruition. The importance of creating high-resolution physical copies has been reassessed in light of different types of events that increasingly threaten the protection of cultural heritage. The aim of this research is to analyze the critical issues in the production process of the replicas, focusing on potential problems in data acquisition and processing and on the accuracy of the resulting 3D printing. The metric precision of the printed model with 3D technology are fundamental for everything concerning geomatics and must be related to the same characteristics of the digital model obtained through the survey analysi

Automatic Systems for Digitizing Historical Maps

This work is part of a research branch that studies how to acquire metric, semantic and symbolic information from historical maps without damaging the physical support. The technological growth regarding both mechanical instruments and digital high-resolution sensors allowed the development of suitable tools for the digitization of historical maps and creation of more accurate digital models; therefore, by now, the use of automatic systems for acquisition of digital data is continuously spreading. In the work described in this paper we used a robotic arm (UR10), on which we mounted a digital camera in order to acquire high-resolution images of any object following a regular grid. The arm movement was programmed to keep the rotation angles of the camera constant while shifting it at pre-defined quantities along the two axes. The tests performed demonstrated that we could obtain a three-dimensional model with an accuracy below the millimetre in an almost automatic way

A trait database and updated checklist for European subterranean spiders

Species traits are an essential currency in ecology, evolution, biogeography, and conservation biology. However, trait databases are unavailable for most organisms, especially those living in difficult-to-access habitats such as caves and other subterranean ecosystems. We compiled an expert-curated trait database for subterranean spiders in Europe using both literature data (including grey literature published in many different languages) and direct morphological measurements whenever specimens were available to us. We started by updating the checklist of European subterranean spiders, now including 512 species across 20 families, of which at least 192 have been found uniquely in subterranean habitats. For each of these species, we compiled 64 traits. The trait database encompasses morphological measures, including several traits related to subterranean adaptation, and ecological traits referring to habitat preference, dispersal, and feeding strategies. By making these data freely available, we open up opportunities for exploring different research questions, from the quantification of functional dimensions of subterranean adaptation to the study of spatial patterns in functional diversity across European caves.Peer reviewe

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

Micro UAV photogrammetry: a new procedure for the survey of archeological sites

The project described here intends to deal with and analyse the development and potentialities of micro UAVs (micro Unmanned Aerial Vehicles). In particular, it will focus on the interaction between these vehicles and new multi-image software products, considering the consequences that this system provoked on themethodologyoftraditionalphotogrammetryappliedinthearchaeologicalfield. The purpose of this work is the individuation of the potentialities in the working approach on one side of the UAVsas a mean to acquire metrical information and on the other side of multi-image software products for theprocessingoftheacquired data.Inotherterms,different techniques arecompared andintegrated, inorder tounderstandthepossibilitiesofthisnewmethodology. Finally, the system proposed here has great advantages in terms of versatility, manoeuvrability and costs. Moreover, it is easy to use and produces good results that are interesting as both research and documentation toolsduetotheirrichnessofinformation. In the archaeological field, this system shows its strength as a method to acquire not just metrical data, but also high-resolution images, combining the accuracy on the data acquired, to the potentials of aerial images, usefulforinterpretationanddocumentationpurposes

Digitization of maps belonging to cultural heritage

maps are an essential documentary heritage for the knowledge of ter-ritory. Digitization, in the case of old maps, cannot be a simple high-resolution two-dimensional scan, but it has to detect the geometry of the supporting material. This work describes part of an on-going project, developed by the Laboratory of Photo-grammetry of IUAV University, concerning the study of different methodologies and tools for the 3D digitization of old maps. In particular, high-resolution cameras, combined with a mechanical positioning system and appropriate software for the rigorous construction of “mosaics”, will be explored as a potential means of replacing the expensive large format flatbed scanners. The research aims to digitally record the shape of maps, not only consid-ering their semantic content (printed image), but also their three-dimensional surfaces, and their subjection to time and deformations. Through the development of new algorithms, procedures and mechanical properties, it will be possible to obtain a rigorous three-dimensional geometric memory of the original cartographic heritage

3D printing : state of the art and future perspectives

In the last years, the development of 3D technologies applied to the field of Cultural Heritage (CH) has led to results of the utmost importance from the point of view of preservation, valorisation, communication and fruition of our assets. In particular, we experienced many interdisciplinary projects in which, thanks to the cooperation of different fields of research, incredible results have been obtained, through the technological collaboration of computer graphics and documentation, of industrial engineering and preservation and access of CH. This paper aims at drawing attention to the actual technologies in use for solid printing (digital fabrication) used for the realization of material copies, therefore tangible, of three-dimensional digital virtual models. Even though ulterior developments to these technologies are possibilities to be expected, the process of 3D printing has gradually gained levels of accuracy, which can nowadays be deemed as satisfying. This is even more true in the industrial field (from the manufacturing industry to the design industry), but also in other fields, such as the medical one, for example, for the realization of artificial limbs, and the CH field, which can benefit from new instruments for the restoration and preservation of cultural assets in museums. The metric characteristics of precision and accuracy of the model printed with 3D technology are the fundaments for everything concerning Geomatics, and have to be related with the same characteristics of the digital model obtained through the survey analysis. In other terms, the precision of the printed product must be evaluated in relation to the precision of the instruments used in the analysis. Thus, in the CH field there is the possibility of new systems of access, cataloguing and study, where the models, both virtual and tangible, represent the fundament of visualization and analysis of the form (also from the metric point of view) of each artefact of artistic and historical interest