Search results for "Spectroscopy"
showing 10 items of 10293 documents
Machine learning for rapid mapping of archaeological structures made of dry stones – Example of burial monuments from the Khirgisuur culture, Mongoli…
2020
11 pages; International audience; The present study proposes a workflow to extract from orthomosaics the enormous amount of dry stones used by past societies to construct funeral complexes in the Mongolian steppes. Several different machine learning algorithms for binary pixel classification (i.e. stone vs non-stone) were evaluated. Input features were extracted from high-resolution orthomosaics and digital elevation models (both derived from aerial imaging). Comparative analysis used two colour spaces (RGB and HSV), texture features (contrast, homogeneity and entropy raster maps), and the topographic position index, combined with nine supervised learning algorithms (nearest centroid, naive…
Multi-analytical study of the medieval wall paintings from the rupestrian church Grotta del Crocifisso at Lentini (eastern Sicily): new evidence of t…
2022
AbstractThis study presents the results of the examination and characterisation of the wall paintings that decorate the rupestrian church named Grotta del Crocifisso, which is located in the territory of Lentini (eastern Sicily, few tens of kilometres from Catania and Syracuse). The earliest mural paintings in the church date back to the twelfth century AD. A multi-analytical approach was adopted for the characterisation of stone materials, secondary degradation products, and pigments. For this purpose, the following techniques were used: reflected light microscopy (RLM), polarised light microscopy on thin sections (PLM), X-ray powder diffraction (XRPD), mercury intrusion porosimetry (MIP),…
Analytical studies of the Sirocco room of Villa Naselli-Ambleri: A XVI century passive cooling structure in Palermo (Sicily)
2015
Abstract This work focuses on a passive cooling architecture particularly popular from the Renaissance in Palermo area, as building sumptuous suburban villas became a real hobby for the Sicilian aristocracy. A Sirocco room is an artificial subterranean construction, built close to a water spring in order to reproduce the pleasant conditions of freshness that could be experienced in a natural cavern. In these places, nobles used to spend their time with friends to escape from the hot summer. The room of Villa Naselli-Ambleri is nowadays the best preserved in Palermo thanks to its owners’ conservation care and it is unique for its cooling operating principle. The above-mentioned consideration…
Design and implementation of an augmented reality application for rock art visualization in Cova dels Cavalls (Spain)
2019
[EN] Prehistoric rock art paintings, specifically rock-shelters exposed to environmental and anthropogenic factors, are usually faint and severely damaged, being them difficult to identify and understand by visitors. Augmented Reality (AR) supplements reality with virtual information superimposed onto the real world. This sensor-based technology in smartphones/tablets can improve the paintings experience displaying the 2D digital tracings overlapped onto the real scene (rock with faint paintings). This paper presents an AR application (app) developed in Cova dels Cavalls that shows a recreation of a possible original composition full of motifs with descriptive information to improve current…
Multi‑light photogrammetric survey applied to the complex documentation of engravings in Palaeolithic rock art: the Cova de les Meravelles (Gandia, V…
2022
AbstractThe new phase of study and revision of the Palaeolithic art of the Cova de les Meravelles, as well as the advances made in the field of 3D documentation in recent years, have motivated a new documentation campaign on the main panel full of tiny engraved motifs. The difficulties involved in acquiring and processing data executed using fine and thin engraving techniques indoors, have been solved through a multi-light photogrammetric survey, photographing the main panel surface with five lighting directions, and applying principal component analysis (PCA). This procedure has allowed us to obtain a large corpus of two and three-dimensional data and to improve the documentation base prod…
Color degradation mapping of rock art paintings using microfading spectrometry
2021
[EN] Rock art documentation is a complex task that should be carried out in a complete, rigorous and exhaustive way, in order to take particular actions that allow stakeholders to preserve the archaeological sites under constant deterioration. The pigments used in prehistoric paintings present high light sensitivity and rigorous scientific color degradation mapping is not usually undertaken in overall archaeological sites. Microfading spectrometry is a suitable technique for determining the light-stability of pigments found in rock art paintings in a non-destructive way. Spectral data can be transformed into colorimetric information following the recommendations published by the Commission …
Valuing cultural heritage: the social benefits of restoring and old Arab tower
2005
Abstract Cultural heritage protection is a key issue around the world today. In this paper, the contingent valuation method has been applied to obtain the social benefits that stem from the restoration of an old Arab tower in the Valencia Region of Spain. Due to a current and past lack of protection, the remains of this historic monument are few. Therefore, 252 individuals were randomly interviewed. On conducting our study we distinguished between low, average, and high consumers of cultural goods. Our main finding is that the mean willingness to pay (WTP) is considerably higher for the second group. To give further credence to this observation both parametric and non-parametric approaches …
Mosaic floors of roman Villa del Casale: Principal component analysis on spectrophotometric and colorimetric data
2013
Abstract Spectrophotometric and colorimetric data obtained during a measurement campaign aimed at supporting the Roman "Villa del Casale" (Piazza Armerina, Sicily, Italy) conservation activities, are presented. Special attention was paid to the possible variation of the chromatic coordinates, possibly due to the interventions of cleaning, consolidation, and protection. Data have been analyzed by the Principal Component Analysis (PCA) statistical technique, with the attempt to investigate its role in data variability reduction and verify its effectiveness in interpreting the phenomena occurring on the mosaic surface of the Villa, through grouping the observations into homogenous clusters. Ef…
A methodological approach in the evaluation of the efficacy of treatments for the dimensional stabilisation of waterlogged archaeological wood
2010
Abstract The aim of the work is to set up a methodological approach to verify the effectiveness of the treatments of decayed waterlogged archaeological wood and to point out the proper thermo-hygrometric conditions for its preservation after treatment. The treatments were performed on wood samples of maritime pine (Pinus pinaster Aiton), oak (Quercus sp. caducifolia), elm (Ulmus cf. minor) and strawberry tree (Arbutus unedo L.), obtained from stems pertaining to the original vegetation found in the excavation site of the Ancient Ships in Pisa (Italy), and dated from seventh century BC to second century AD The utilised products were: Polyethylene Glycols (PEG) of various molecular weights, a…
Documenting carved stones by 3D modelling – Example of Mongolian deer stones
2018
Rock art studies are facing major technical challenges for extensive documentation. Nowadays, recording is essentially obtained from time-consuming tracing and rubbing, techniques that also require a high level of expertise. Recent advances in 3D modelling of natural objects and computational treatment of the modelled surfaces may provide an alternative, and reduce the current documentation bottleneck. The aim of this study is to examine the extent to which such treatments can be applied. The case study presented here concerns the famous deer stones erected by ancient Mongolian nomad populations. The 3D acquisition workflow is based on structure-from-motion, a versatile photogrammetric tech…