Search results for "Metro"
showing 10 items of 620 documents
Comparaison de la mesure des déformations de fantômes de l’aorte à partir d’image obtenues par IRM et stéréovision
2015
International audience; The study of the wall strain distribution could be helpful to improve the decision criterion for surgery of aortic aneurysm. Recently, numerical simulations can complete the data obtained from imaging measurement in order to develop reliable models. However, the used medical imaging tools are not experimentally validated, in metrological point of view. The aim of this study focused on accuracy and reliability of measurement obtained from kinetic MR sequences. The measures of deformations from MRI were compare to those obtained from stereovision system. Cylindrical phantom of silicone material similar to arterial behavior simulated a symmetric aneurysm was designed. A…
Phase Noise and Frequency Stability of the Red-Pitaya Internal PLL
2019
In field-programmable gate array platforms, the main clock is generally a low-cost quartz oscillator whose stability is of the order of $10^{-9}$ to $10^{-10}$ in the short term and $10^{-7}$ to $10^{-8}$ in the medium term, with the uncertainty of tens of ppm. Better stability is achieved by feeding an external reference into the internal phase-locked loop (PLL). We report the noise characterization of the internal PLL of Red-Pitaya platform, an open-source embedded system architected around the Zynq 7010 System on Chip, with analog-to-digital and digital-to-analog converters. Our experiments show that, providing an external 10-MHz reference, the PLL exhibits a residual frequency stability…
Three-dimensional level-curve scanning based on intersection of laser lines
2005
A dimensional measurement system that also tracks object movements is presented here. The method directly yields the level curves of an object. It is an extension of collimation methods, coupled with the use of structured lighting with features formed from several luminous planes intersecting in a single line. This line defines a set of points of the space at a fixed distance Z 0 from the measuring head. The locus of the points of the object where the lighting is reduced to a single line is the level curve sought. The introduction of an asymmetry into the lighting structure permits one to determine the direction as well as an approximate value of the value of the distance to the level curve…
Displacement measurements in structural elements by optical techniques
2000
Speckle metrology and holographic interferometry (HI) have been used in several civil engineering applications. We present the results obtained by applying speckle photography (SP) to the study of two quadratic shearwalls with different boundary conditions, and the potential of the technique in the study of this kind of structures is described. The analysis of Young's fringes obtained with this technique at certain points on each shearwall provides the whole field of displacement measurements. HI has been used to measure the three components of absolute displacement, verifying that the bulging phenomenon does not affect the in-plane components when the applied load remains on the same plane…
Real-time Sub-pixel Cross Bar Position Metrology
2002
Many measurement application fields need to calculate cross bar intersection locations of horizontal and vertical bars. The system we developed and that we present in this paper is an embedded system that measures cross bar positions with sub-pixel accuracy on 1024×1024 pixel images delivered by a camera at a 50 MHz data rate in real time. This is done using an algorithm that looks for intersection areas and then locally calculates two lines representing horizontal and vertical bars. The two line intersection is considered to be the bar intersection. To achieve real time, we developed a hybrid architecture in which low level processes are implemented into FPGAs and others into DSPs. As a re…
Planning
2022
The chapter seeks to explore the role urban planning can play in the decision-making process within large urban areas. In the first part, the concept of planning is explored through different theoretical perspectives, while in a second section how urban agglomerations and metropolitan areas are viewed in the planning literature are analyzed. In the last sections the paper describes how urban and regional planning has evolved faced with the development issues of large urban areas and some ways to give planning an appropriate role in shaping metropolitan development are suggested.
Clinical use of the ocular point spread function for retinal image quality assessment
2008
The purpose of this study is to demonstrate the clinical use of the point spread function (PSF) as metric for the assessment of retinal image quality in eyes with different ocular conditions. The PSF was computed from the wavefront aberrations obtained in seven eyes with different ocular conditions: emmetropia, myopia, hyperopia, post-myopic laser in situ keratomileusis (LASIK), post-hyperopic LASIK, keratoconus, Intacs ® in keratoconus, radial keratotomy (RK), LASIK after RK, cataract, phacoemulsification after cataract surgery, and LASIK after astigmatic keratotomy. The Strehl intensity ratio was calculated for all the PSFs computed. The PSF was correlated with the change in the optical e…
Industry vs. Services
2017
This chapter examines the difficulties of the country to emerge as an industrial power, despite the rich mineralization of the country, which has given birth to a proliferation of mines and conflicts focusing on the environmental and social consequences of mining. More than the lack of abundant energy reserves, the choices of the economic and political leaders have not been conducive to an industrial takeoff similar to neighboring countries. The steel and garment industries have never been very strong, the automobile cluster of Laguna province is much less impressive than what is seen in Thailand, and the high-tech industry works mostly for foreign companies, in the absence of any major ind…
Sulle tracce della post-metropoli: l’area metropolitana di Palermo
2017
Il contributo propone una lettura interpretativa dei fenomeni post-metropolitani palermitani alla luce del mutare negli ultimi decenni delle condizioni sociali e dei modelli spaziali di occupazione del suolo. Il contributo è suddiviso in quattro sezioni: una prospettiva socio-economica che descrive le caratteristiche demografiche e relative al mondo del lavoro; un’analisi spaziale su abitazioni e uso del suolo; un approfondimento sui processi di privatizzazione dello spazio; infine, una descrizione della questione legata alle nuove aree metropolitane nella sua declinazione palermitana. Ogni sezione descrive le tendenze più consolidate in questo settore, ma discute anche i cambiamenti più in…
La Sicilia Sud-Orientale, una regione post-metropolitana controfattuale
2017
Il contributo propone una lettura interpretativa dei fenomeni post-metropolitani nella Sicilia Sud-Orientale alla luce del mutare negli ultimi decenni delle condizioni sociali e dei modelli spaziali di occupazione del suolo. Il contributo è suddiviso in tre sezioni: una prospettiva socio-economica che descrive le caratteristiche demografiche e relative al mondo del lavoro; un’analisi spaziale su abitazioni e uso del suolo; e, infine, una descrizione dello stato dell’arte delle politiche urbane e della pianificazione a Siracusa e Ragusa. Ogni sezione descrive le tendenze più consolidate in questo settore, ma discute anche i cambiamenti più innovativi e le sfide che il Sud-Est si trova ad aff…