Search results for "Geometric"
showing 10 items of 652 documents
Discriminazione di presunte specie criptiche: un approccio di morfometria geometrica in Brachidontes pharaonis-variabilis (Bivalvia, Mytilidae).
2010
3D Geometric morphometrics to investigate Cercopithecini evolution
2014
3D Geometric Morphometrics has been used on a preliminary dataset of 163 crania and 148 mandibles of primates. We sampled 27 species from Cercopithecidae and Hominidae, collected in 7 different museums. Our sampling campaign was carried on with the use of a 3D-digitizer Microscribe G2X and the data were processed through the software Morphologika. The preliminary PCA analyses on crania highlight the presence of two different groups, which distinguish some Chlorocebus and Unknown Cercopithecus samples from all the others. Regarding on mandibular shape analyses, we found a light cluster of Cercopithecus samples. The “Sex” variable does not affect the reliability of the analysis, probably beca…
GEOMETRY OF DISSIPATIVE PHASE TRANSITIONS
The main objective of this thesis is the development of geometrical methods for the investigation of critical phenomena. In particular, a novel approach based on the Uhlmann curvature is introduced for the investigation of non-equilibrium steady-state quantum phase transitions (NESS-QPTs). Equilibrium phase transitions fall invariably into two markedly non-overlapping categories: classical phase transitions and quantum phase transitions. NESS-QPTs offer a unique arena where such a distinction fades off. We propose a method to reveal and quantitatively assess the quantum character of such critical phenomena. We apply this tool to a paradigmatic class of lattice fermion systems with local res…
The Cuneiform Brick
2022
The study presents some results of an experimental research on brick wall cladding, proposing methodological approaches for the creation of new geometric-compositional configurations. Citing innovative case studies of historical and contemporary architecture, the research has allowed to determine a different geometric shape of the brick, which takes its cue from the traditional wedge-shaped brick in majolica brick, widespread in Sicily since the sixteenth century for the realization of cusps and domes. Through the definition of procedural parametric algorithms for the analysis and geometric-spatial control, it is described the path that led to the digital prototype of a modular component of…
Il mattone cuneiforme maiolicato. Procedure algoritmico-parametriche digitali come strumento di indagine e progettazione: dall'architettura storica a…
2020
The study focuses on the cuneiform in majolica brick that has been widespread in Sicily since the 16th century for the construction of spires and domes. A unifying element that has constituted a particular identity contribution to the island’s brick tradition; an original solution able to combine aesthetics with structural and durability. On the basis of more than a hundred examined cases, the different geometrical-formal peculiarities detected in relation to the characteristics of the shell are described. Some analyses and checks of the traditional geometrical composition patterns of the wall facade are reported. Through the definition of digital tools of algorithmic-parametric design, new…
The tree of life in the southern porch of the cathedral of Palermo: survey and geometric analysis
2016
This study focuses one of the most puzzling works of art made in Palermo at the end of the medieval age: the tree of life, a rich geometrical decoration with animal and human figures in the southern porch of the Cathedral of Palermo. Topographic and SfM photogrammetric methods produced a detailed orthophoto of the porch. Images collected during restoration have been rectified and superimposed to the orthophoto. The geometrical analysis of the decorative patterns reveals a complex design and meaningful links between the decoration and the general architectural layout of the porch.
La rappresentazione dell'architettura in alcuni rivestimenti musivi di epoca medievale in Sicilia
2019
Nei mosaici che decorano le chiese costruite in Sicilia nel XII dai re normanni compaiono rappresentazioni di edifici. Tali rappresentazioni, come frequentemente accade in epoca pre-rinascimentale, condensano, per accostamento, diverse ‘viste’ dello stesso edificio. La presenza negli edifici normanni di pavimenti e manufatti lignei decorati secondo pattern geometrici, ha suggerito la ricerca di analoghi tracciati nei rivestimenti musivi. L’analisi grafica propone la presenza di quadrati e ottagoni stellati in un mosaico della Cappella palatina di Palermo che raffigura un padiglione coperto da una cupola. Many buildings are depicted in the mosaic panels that enrich the churches built in Sici…
Costruzione omologica e rappresentazione digitale di una sezione conica
2012
La trattazione del luogo geometrico conica assume carattere di grande generalità nell’applicazione dei metodi della Scienza della Rappresentazione. Lo studio teorico e pratico delle proprietà di questa curva trova contributi fin dai tempi antichi delineando, nel corso dei secoli, diversi approcci culturali che tracciano momenti salienti dell’evoluzione del pensiero geometrico/matematico. Risulta affascinante osservare che l’interesse profuso in questo campo di indagine ha delineato vari aspetti legati alla concezione e alla generazione delle linee curve deducendone le proprietà intrinseche. Si espone un’inedita via risolutiva, attraverso procedimenti omologici, per la costruzione del profil…
Graph-based minimal path tracking in the skeleton of the retinal vascular network
2012
This paper presents a semi-automatic framework for minimal path tracking in the skeleton of the retinal vascular network. The method is based on the graph structure of the vessel network. The vascular network is represented based on the skeleton of the available segmented vessels and using an undirected graph. Significant points on the skeleton are considered nodes of the graph, while the edge of the graph is represented by the vessel segment linking two neighboring nodes. The graph is represented then in the form of a connectivity matrix, using a novel method for defining vertex connectivity. Dijkstra and Floyd-Warshall algorithms are applied for detection of minimal paths within the graph…