From survey to fem analysis for documentation of built heritage: The case study of villa revedin-bolasco

In the last decade advances in the fields of close-range photogrammetry, terrestrial laser scanning (TLS) and Computer Vision (CV) have enabled to collect different kind of information about a Cultural Heritage objects and to carry out highly accurate 3D models. Additionally, the integration between laser scanning technology and Finite Element Analysis (FEA) is gaining particular interest in recent years for structural analysis of built heritage, since the increasing computational capabilities allow to manipulate large datasets. In this note we illustrate the approach adopted for surveying, 3D modeling and structural analysis of Villa Revedin-Bolasco, a magnificent historical building located in the small walled town of Castelfranco Veneto, in northern Italy. In 2012 CIRGEO was charged by the University of Padova to carry out a survey of the Villa and Park, as preliminary step for subsequent restoration works. The inner geometry of the Villa was captured with two Leica Disto D3a BT hand-held laser meters, while the outer walls of the building were surveyed with a Leica C10 and a Faro Focus 3D 120 terrestrial laser scanners. Ancillary GNSS measurements were also collected for 3D laser model georeferencing. A solid model was then generated from the laser global point cloud in Rhinoceros software, and portion of it was used for simulation in a Finite Element Analysis (FEA). In the paper we discuss in detail all the steps and challenges addressed and solutions adopted concerning the survey, solid modeling and FEA from laser scanning data of the historical complex of Villa Revedin-Bolasco

Recovery trends of commercial fish: the case of an underperforming Mediterranean marine protected area

Temporal trends in the recovery of exploited species in marine protected areas (MPAs) are useful for a proper assessment of the efficacy of protection measures. The effects of protection on the fish assemblages of the sublittoral rocky reefs in the \u201cPenisola del Sinis-Isola di Mal di Ventre\u201d MPA (W. Sardinia, Italy) were evaluated using a multi-year series of data. Four surveys, conducted 7, 10, 13 and 15 years after the area was designated as an MPA and carried out in the period spanning June and July, were used to estimate the abundance and biomass of commercial species. The surveys were carried out in zones with decreasing levels of fishing restrictions within the MPA (zones A, B, C) and in unprotected zones (OUT1 and OUT2), and underwater video visual census techniques were used. Protected zones only occasionally showed higher levels of abundance or biomass, and the trajectories of those metrics were not consistent across the years. In addition, the zone with the highest level of protection (zone A) never presented levels of abundance and biomass higher than those in zones B and C. This study shows that even 15 years after designation, protection has had no appreciable effect in the MPA studied. It is argued that this is emblematic of several shortcomings in the planning, regulation and enforcement frameworks of the MPA

INTEGRAZIONE DI TECNICHE DI RILEVAMENTO PER IL CONTROLLO DI STABILITÀ DI UNA STRUTTURA STORICA

RIASSUNTO Negli anni recenti, la possibilità offerta dal laser scanner terrestre di acquisire grandi quantità di dati in tempi relativamente brevi, con un grado di precisione e dettaglio elevati, ha spinto l’interesse di topografi, ingegneri, architetti e archeologi a considerare il laser a scansione come uno strumento di rilevamento fondamentale per la modellazione 3D di oggetti e ambienti facenti parte del Patrimonio Culturale di una nazione. Prova di tale fenomeno è costituito dall’ampia varietà di oggetti che sino ad oggi sono stati sottoposti a scansione: dal piccolo pezzo di ceramica alla statua di marmo, dall’edificio storico ad un intero sito archeologico. D’altra parte, nel panorama dei possibili impieghi del laser a scansione, la sua applicazione per il controllo di stabilità di una struttura o edificio di interesse storico appare tutt’ora un campo di ricerca poco indagato. Al fine di approfondire questa tematica di ricerca, è stato attivato un progetto triennale volto a verificare la possibilità di utilizzare in modo integrato una molteplicità di tecniche di rilevamento per il controllo della stabilità di una struttura storica caratterizzata da una geometria complessa. In particolare, tale progetto prevede di utilizzare strumentazione laser scanner terrestre, stazione totale, flessimetri, fotogrammetria e termografia per effettuare una serie di rilievi a cadenza semestrale del Teatro Anatomico dell’Università di Padova. Lo scopo del progetto in questione è quello di verificare la stabilità nel tempo di questo tipo di struttura, considerando in particolare gli effetti del decadimento organico delle parti in legno. In questa nota vengono quindi presentati i risultati ottenuti finora, ponendo particolare attenzione ai problemi e difficoltà insorte nel rilievo laser scanner e modellazione 3D di una struttura di interesse storico e culturale caratterizzata da una geometria inusuale e alquanto complessa. ABSTRACT The chance provided by terrestrial laser scanners to achieve, in short time, very dense, accurate and detailed 3D data drew in recent years the interest of surveyors, engineers, architects and archaeologists towards the laser scanning technique as an invaluable surveying mean for 3D modeling of sites and artifacts of cultural heritage. A wide variety of objects, e.g., small pieces of pottery, statues, buildings, and large areas of archaeological sites, have been scanned and modeled for various purposes like preservation, reconstruction, study, and museum exhibitions. However, the use of TLS systems for stability control is still a research field not much investigated. In the view of insight investigation on this topic, a three-years project has been established in order to evaluate the use of multiple surveying techniques for the stability control of a complex historical structure. To this aim, terrestrial laser scanning (TLS), total station (TS), deflectometers, photogrammetry and thermography are being employed to perform on a 6 month basis a set of surveys of the Anatomy Theatre, one of the oldest, most important and best-known historical “medical” buildings. Located inside the Palazzo del Bo’, the building seat of the University of Padua, Italy. The main goal of this work is to verify the stability over the time of this kind of structure, given the inherent organic decay of the wooden parts. In this paper we present the results obtained from the repeated surveys and highlight issues and difficulties related to the laser scanning of an unusual geometry such as the one provided by the Anatomy Theatre of the University of Padua

Dynamics and control of the expansion of finite-size plasmas produced in ultraintense laser-matter interactions

The strong influence of the electron dynamics provides the possibility of controlling the expansion of laser-produced plasmas by appropriately shaping the laser pulse. A simple irradiation scheme is proposed to tailor the explosion of large deuterium clusters, inducing the formation of shock structures, capable of driving nuclear fusion reactions. Such a scenario has been thoroughly investigated, resorting to two- and three-dimensional particle-in-cell simulations. Furthermore, the intricate dynamics of ions and electrons during the collisionless expansion of spherical nanoplasmas has been analyzed in detail using a self-consistent ergodic-kinetic model. This study clarifies the transition from hydrodynamic-like to Coulomb-explosion regimes

ACCURACY ENHANCEMENT OF UNMANNED HELICOPTER POSITIONING WITH LOW COST SYSTEM

In the last years UAV (Unmanned Aerial Vehicle) systems are become very actractive for various commercial, industrial, public, scientific and military operations. The tasks include pipeline inspection, dam surveillance, photogrammetric survey, infrastructure maintenance, inspection of flooded areas, fire fighting, terrain monitoring, volcano observations and so on. The impressive flying capabilities provided by UAVs require a well trained pilot to be fully and effectively exploited; moreover the flight range of the piloted helicopter is limited to the line-of-sight or the skill of the pilot to detect and follow the orientation of the helicopter. Such issues have motivated the research and the design for autonomous system guidance which could both stabilize and also guide the helicopter precisely along a reference path. The constant growth of research programs and the technological progress in the field of navigation systems, as denoted by the production of more and more performing GPS/INS integrated units, allowed a strong cost reduction and payload miniaturization, making the design of low cost UAV platforms more feasible and actractive. Small autonomous helicopters have demonstrated to be a useful platform for a number of airborne-based applications such as aerial mapping and photography, surveillance (both military and civilian), powerline inspection and agricolture monitoring. In this paper we present the results of a flight simulation system developed for the setup of the servos which our autonomous guidance system will be based on. Building a simulated environment allows, indeed, to evaluate in advance what are the main issues of a complex control system, avoiding to damage fragile and expensive instruments as the ones mounted on a model helicopter

A BACKPACK MMS APPLICATION

Over the years, MMS systems have demonstrated that accuracies suitable for all but the most demanding cadastral and engineering applications can be achieved. This result, combined with a reduction in both the time and cost of data collection, made MMS a very interesting technology potentially able to meet the demand of GIS operators for rapid spatial data updating. However, the high costs involved in the arrangement of such systems did not favoured their growth in the market, so that MMS are still today mainly operated by the companies or institutions that build them. To allow a wider community of spatial data user to benefit of mobile mapping applications - in particular the lower costs and greater efficiency of data collection – a portable systems, the Backpack MMS, was developed at the University of Calgary MMS in 2001. The research centre of CIRGEO re-implemented such system introducing a few significative changes due to the adoption of different hardware and software solutions with respect to the original project. Then, within a collaborative work with a research team of the Vesuvius Observatory, in summer 2006 this version of the Backpack MMS was tested in a real environment: the goal was to assess the effectiveness of the Backpack as a tool for mapping evacuation routes on areas subjected to natural hazards. In this paper we report a description of our system configuration and the results of performed test along with a few comments on practical issues that affected the final accuracy of mapped routes

Seasonality of Marriages and Ecological Contexts in Rural Communities of Central-Southern Italy (Abruzzo), 1500–1871

The seasonality of 27,705 marriages celebrated in a four century span in the Province of Teramo (Abruzzo, Italy) was analyzed to identify the presence of a long-term pattern related to the prevailing subsistence activity and the main factors affecting it. The results show general agreement in all centuries with the agricultural patterns of other lowland or south-central Italian groups (Piedmont, Veneto, Liguria, Emilia Romagna, Tuscany, Latium, Campania, Apulia) and Mediterranean regions (Spain, France), although with some differences. Religious factors strongly affected the timing of marriage only during Lent. Of interest is the progressive increase through the centuries of marriages in the summer-autumn months, associated with a decrease in January and February. This suggests the passage from a summer migration system to a rural sedentary system with occasional seasonal work

COMPARING DATA ACQUISITION METHODOLOGIES FOR DTM PRODUCTION

In this paper we present the results related to several field campaigns conducted in the last three years in a small (4.4 km2) wilderness basin in Carnia, a tectonically active alpine region in northeast Italy. The study area is a typical alpine debris-flow dominated catchment where several landslides, including a significantly large one, were observed and mapped. The field survey carried out in 2007, 2008, 2009 and 2010 were focused on the large landslide of the basins and they consisted in the following steps: 1 – development of an accurate GPS network, 2 – make use of a long range Terrestrial Laser Scanner (TLS) for a detailed and local analysis of landslide movements, 3 – merge the data with an airborne LiDAR for a large scale analysis of the processes. Preliminary analysis consist in the comparison of different high resolution Digital Terrain Models (DTMs) in order to estimate the debris volume that has been triggered during the last movements of the landslides. Achieved results show that the integration between ALS and TSL data allows to produce DTMs of limited extent, with higher quality and level of detail. Such DTMs improve the capabilities for landslides analysis and modelling with respect to the use of LiDAR data only, even in areas providing limited or difficult access for the survey activity

All-optical trapping and acceleration of heavy particles

A scheme for fast, compact, and controllable acceleration of heavy particles in vacuum is proposed, in which two counterpropagating lasers with variable frequencies drive a beat-wave structure with variable phase velocity, thus allowing for trapping and acceleration of heavy particles, such as ions or muons. Fine control over the energy distribution and the total charge of the beam is obtained via tuning of the frequency variation. The acceleration scheme is described with a one-dimensional theory, providing the general conditions for trapping and scaling laws for the relevant features of the particle beam. Two-dimensional, electromagnetic particle-in-cell simulations confirm the validity and the robustness of the physical mechanism.Comment: 10 pages, 3 figures, to appear in New Journal of Physic