Search results for "OPTICS"
showing 10 items of 10033 documents
CONSTRUCTION OF A GEOGRAPHICAL DATABASE OF CLASSICAL-ARCHAIC MANUFACTURES, FOUND IN THE SURVEY OF THE GREEK COLONY HIMERA (SICILY, ITALY). APPLICATIO…
2012
Abstract. This research has analysed the distribution of ceramic finds from classical and archaic ages in the territory of the ancient Greek colony Himera, a town situated near Termini Imerese, in the province of Palermo (Sicily, Italy), which has been the site of systematic excavations carried out by the University of Palermo since the Sixties. The study of about 1500 ceramic fragments, dated back to the 6th-5th century B.C., has allowed to develop an approach to the understanding of the role played by ceramics in the relations between different societies and cultures. Besides the most common analysis factors for the ceramic manufactures, such as their production and distribution, a major …
3D RECONSTRUCTION-REVERSE ENGINEERING- DIGITAL FABRICATION OF THE EGYPTIAN PALERMO STONE USING BY SMARTPHONE AND LIGHT STRUCTURED SCANNER
2018
Abstract. This paper presents a pipeline that has been developed to acquire a shape with particular features both under the geometric and radiometric aspects. In fact, the challenge was to build a 3D model of the black Stone of Palermo, where the oldest Egyptian history was printed with the use of hieroglyphs. The dark colour of the material and the superficiality of the hieroglyphs' groove have made the acquisition process very complex to the point of having to experiment with a pipeline that allows the structured light scanner not to lose the homologous points in the 3D alignment phase. For the texture reconstruction we used a last generation smartphone.
Nonlinear Disorder Mapping Through Three-Wave Mixing
2010
We implement a simple and powerful approach to characterize the domain distribution in the bulk of quadratic ferroelectric crystals via far-field second-harmonic spectroscopy. The approach is demonstrated in a lithium tantalate sample with periodic electric field poling and random mark-to-space ratio.
SHIFTS OF START AND END OF SEASON IN RESPONSE TO AIR TEMPERATURE VARIATION BASED ON GIMMS DATASET IN HYRCANIAN FORESTS
2018
Abstract. Climate change is one of the most important environmental challenges in the world and forest as a dynamic phenomenon is influenced by environmental changes. The Hyrcanian forests is a unique natural heritage of global importance and we need monitoring this region. The objective of this study was to detect start and end of season trends in Hyrcanian forests of Iran based on biweekly GIMMS (Global Inventory Modeling and Mapping Studies) NDVI3g in the period 1981-2012. In order to find response of vegetation activity to local temperature variations, we used air temperature provided from I.R. Iran Meteorological Organization (IRIMO). At the first step in order to remove the existing g…
FOR A CONSCIUOS FRUITION OF THE CULTURAL HERITAGE OF ANCIENT NOTO (SICILY). EFIAN PROJECT AS OPPORTUNITY FOR VALORISATION
2017
Abstract. The archaeological site of Ancient Noto is all that remains of one of the most interesting and important cities in the Est part of Sicily. Architecture and political life made Noto a point of reference for the island, expecially in XVI and XVII century, before it was destroyed by a devastating earthquake in 1963. A general project of safeguard, together with archaeological excavations, could hand a great amount of information, archaeological finds, pieces of architecture, that are useful to understand the site, known as a "Sicilian Pompei". Our intervention has the aim to describe the importance of EFIAN (Experimental Fruition Ingenious Ancient Noto). The project is carried out as…
Employing Microwave Graphene Field Effect Transistors for Infrared Radiation Detection
2018
In this work, we investigate the possibility of employing graphene field effect transistors, specifically designed for microwave applications, as infrared detectors for telecom applications. Our devices have been fabricated on a sapphire substrate employing CVD-grown transferred graphene. The roles of both the gate dielectric and the DC bias conditions have been evaluated in order to maximize the infrared generated signal through an experimental investigation of the signal-to-noise ratio dependence on the transistor operating point.
3D RECONSTRUCTION OF THE ROMAN DOMUS IN THE ARCHAEOLOGICAL SITE OF LYLIBAEUM (MARSALA, ITALY)
2019
Abstract. Generally, terrestrial laser scanning surveys involve a rather large number of scans to ensure a high percentage of overlap required for the scan registration phase (target-based or point-based registration, cloud-to-cloud registration). These approaches result in data redundancy that could slow down both the acquisition and post-processing phases. In recent years, the technological evolution in the field of laser scanners has been directed to the development of devices that are able to perform an onsite pre-registration, to optimize the survey procedures and the reliability of the registration of the scan. The paper presents the results achieved during a terrestrial laser scannin…
THE INTEGRATED 3D SURVEY for UNDERGROUND ARCHAEOLOGICAL ENVIRONMENT
2019
Abstract. The task of documentation and conservation of Cultural Heritage defines the challenges that geomatics techniques have to overtake in order to provide different solutions that combine the automation of processes with accurate results. The employment of integrated technologies allows improving the documentation of Cultural Heritage from a quantitative and qualitative point of view. The use of range and image-based techniques ensures the possibility to completely record articulated structures such as building with underground environments. The latter present often problematic survey conditions that imposed well planned and appropriate solutions. In this context, the paper presents th…
DIGITAL PHOTOGRAMMETRY, TLS SURVEY and 3D MODELLING for VR and AR APPLICATIONS in CH
2020
Abstract. The world of valorization of Cultural Heritage is even more focused on the virtual representation and reconstructions of digital 3D models of monuments and archaeological sites. In this scenario the quality and the performances offered by the virtual reality (VR) and augmented reality (AR) navigation take primary importance, improving the accessibility of cultural sites where the real access is not allowed for natural conditions or human possibilities. The creation of a virtual environment useful for these purposes requires a specific workflow to follow, combining different strategies in the fields of survey, 3D modelling and virtual navigation. In this work a specific case of stu…
Supercontinuum Generation and Intermodal Four-Wave Mixing in a Step-Index Few-Mode Fibre
2019
International audience; The complex spatiotemporal dynamics of nonlinear light propagation in multimode fibers (MMFs) has recently witnessed a renewed interest because of their experimental realization in emerging key areas of laser physics and fiber optics [1]. Specifically, MMFs have a number of linear and nonlinear optical properties that make them very attractive to investigate new spatiotemporal effects fundamentally different from standard single-mode fibers. These include the observation of multimode solitons [2], intermodal four-wave mixing (FWM) [3], geometric parametric instabilities [4], spatial beam self-cleaning [5], and the generation of supercontinuum (SC) light when pumping …