Search results for "SCANNER"
showing 10 items of 170 documents
The Technologies of Architectural Survey: A New Comparison Based on the Tower of Sotillo de la Ribera, Burgos
2017
The paper offers an original research about the analysis and the comparison of different techniques of survey concerning the architectural field – image-based and range-based – throughout the development of the theory of errors in order to evaluate reliability and precision of the results. In particular, this analysis will be focused on the tower of the parochial Church of Santa Águeda, a building located in the small village of Sotillo de la Ribera, within the province of Burgos (Spain). The first part of this work, therefore, has been submitted to the implementation of different methodologies, from the direct survey used as a basis, to the procedure to represent graphically the results (e…
I Telamoni del Tempio di Zeus ad Agrigento: rilievi, disegni e ricostruzioni
2013
Oggetto dello studio qui presentato è la ricostruzione di un intercolumnio del fronte esterno del Tempio di Zeus ad Agrigento, basata sul rilievo del Telamone oggi custodito presso il Museo Archeologico, sugli studi e i numerosi saggi di ricostruzione proposti dagli studiosi dal XVIII secolo fino alla metà dello scorso secolo e sulla analisi strutturale del Telamone ricostruito nel Museo. The drawings of the telamones, the giant statues placed the front of the Temple of Zeus in the archaeological area of Agrigento, have fascinated some of the most famous neoclassical architects in Europe. The virtual reconstruction of one intercolumnial of the Temple, based both on the range-based survey of…
Indagine sperimentale su nodi di tralicci in acciaio di travi reticolari miste
2009
Results of experimental tests on welded joints of steel truss of encased composite steel-concrete beams are presented. The welding of the inclined web bars to top bars, both of steel type B450C, and to bottom steel plate, the latter made of S355 steel type, are tested. Two analytical expressions for prediction of welding strength are derived: the one based on a resistance criterion and the other based on a limit domain of the welding section. Guidelines for choosing the effective dimensions of the fillet weld, necessary to determine the strength, are provided. A high precision digital scanner is used to validate the suggested guidelines to determine the geometrical characteristics of the fi…
On the Measurement and Prediction of the Out-of-Plane Displacement Surrounding Cold-Expanded Holes
2010
Experimental measurements of the out-of-plane displacement surrounding cold-expanded holes in a 6082-T6 aluminum alloy were made with a 3D optical scanner using the technique of the encoded light-pattern projection in white light. The measured surface profiles have shown the thickness discontinuity along the hole edge due to the effect of the split in the sleeve. An analytical–numerical solution of the out-of-plane displacement is presented based on existing analytical models. Thus, the results given by the analytical model were then compared with the experimental data and with a finite element (FE) model that simulates the cold-expansion process. The location of the elastic–plastic boundar…
Online dimensional control of rolled steel profiles using projected fringes
2020
AbstractFringe projection is a versatile method for mapping the topography of surfaces. In this paper, it is used to measure the defects on the head of railroad rails while the rails are moving. Railroad rails are made by hot rolling. The quality of the finished product is generally good, but surface texture will deteriorate with increasing temperature. A method for online inspection therefore is very desirable. In the present experiment, dimensional inspection of the railroad rails was made online while moving at a speed of 1–2 m/s. Therefore, it is important to minimize the registration time. To achieve this, we apply a method of fringe location with sub-pixel accuracy that requires only …
Ex vivo measurement reliability using two different cbct scanners for orthodontic purposes
2012
Background There are many cone beam computed tomography (CBCT) scanners available on the market: detector technology, algorithm precision, and scanner settings influence image quality. The aim of this study was to compare the accuracy of linear measurements made on images of the same sample obtained using two different CBCT scanners. Methods Twenty-eight linear measurements between orthodontic anatomical landmarks that were marked with gutta-percha points on a fresh sacrificed lamb head were taken three times. The head was scanned with two CBCT scanners using different scanning parameters. Digital Imaging and Communications in Medicine (DICOM) images were reconstructed and the same measurem…
A Mlp-Based Digit And Uppercase Characters Recognition System
1997
A simple software solution for digit and uppercase handwritten characters recognition is presented. The proposed solution is based on a two-layer Multi Layer Perceptron (MLP) trained by a conjugate gradient descent (CGD) optimization algorithm. This neural network is embedded in a software tool for automatic processing of forms achieved using a scanner. The chosen solutions allow us to obtain good results both in terms of recognition rate and speed. In the paper are fully described design details and experimental results.
Un “laboratorio” di conoscenza nel Mediterraneo. Il Castello Utveggio a Palermo.
2009
Il presente studio approfondisce le tematiche, su esposte, ponendo l’attenzione sull’edificio storico “Il Grande Albergo Castello Utveggio”, che - per scelta di luogo e di destinazione d’uso, eccezionale per avvenimenti tecnici e costruttivi finalizzati a realizzarlo - presenta caratteristiche peculiari di identità di luogo fortemente correlato con la città di Palermo, con il paesaggio della Conca d’Oro e con il territorio. Posto sulla sommità del Primo Pizzo nel settore meridionale del Monte Pellegrino a 346 m s.l.m., è rivolto verso la città e il porto, fu progettato dall’architetto Giovan Battista Santangelo e realizzato nei primi decenni del ‘900.
Study of ambient light influence for three-dimensional scanners based on structured light
2007
Ambient light in a scene can introduce errors into range data from most commercial three-dimensional range scanners, particularly scanners that are based on projected patterns and structured lighting. We study the effects of ambient light on a specific commercial scanner. We further present a method for characterizing the range accuracy as a function of ambient light distortions. After a brief review of related research, we first describe the capabilities of the scanner we used and define the experimental setup for our study. Then we present the results of the range characterization relative to ambient light. In these results, we note a systematic error source that appears to be an artifact…
Radiolucent Carbon Fiber–Reinforced Pedicle Screws for Treatment of Spinal Tumors: Advantages for Radiation Planning and Follow-Up Imaging
2016
Objective Surgical treatment of spinal tumors regularly includes spinal instrumentation with pedicle screws. Most modern pedicle screws are made of titanium alloy, which is associated with artifacts on postoperative imaging such as computed tomography and/or magnetic resonance imaging. These artifacts hamper radiation treatment planning and execution and follow-up imaging. Recently, carbon fiber–reinforced polyetheretherketone (CFRP) implants became available for posterior instrumentation with the aim to reduce imaging artifacts by implants. Methods Patients harboring spinal tumors underwent posterior stabilization using CFRP pedicle screws. Postoperative imaging was evaluated for implant a…