Search results for " topography"
showing 10 items of 102 documents
Sensitivity of the C-band SRTM DEM Vertical Accuracy to Terrain Characteristics and Spatial Resolution
2008
This work reports the results of a careful regional analysis of the SRTM DEM (Shuttle Radar Topography Mission – Digital Elevation Model) vertical accuracy as a function of both topography and Land-Use/Land Cover (LULC). Absolute vertical errors appear LULC-dependent, with some values greater than the stated accuracy of the SRTM dataset, mostly over forested areas. The results show that the structure of the errors is well modeled by a cosine power n of the local incidence angle (θloc). SRTM quality is further assessed using slope and topographical similarity indexes. The results show a lower relative accuracy on slope with a R2 = 0.5 and a moderate agreement (Kappa ≈ 0.4) between SRTM- and …
Short-Term Changes in Light Distortion in Orthokeratology Subjects
2015
Purpose. Quantifying adaptation to light distortion of subjects undergoing orthokeratology (OK) for myopia during the first month of treatment. Methods. Twenty-nine healthy volunteers (age: 22.34 ± 8.08 years) with mean spherical equivalent refractive error −2.10 ± 0.93D were evaluated at baseline and days 1, 7, 15, and 30 of OK treatment. Light distortion was determined using an experimental prototype. Corneal aberrations were derived from corneal topography for different pupil sizes. Contrast sensitivity function (CSF) was analyzed for frequencies of 1.50, 2.12, 3.00, 4.24, 6.00, 8.49, 12.00, 16.97, and 24.00 cpd under photopic conditions. Results. Average monocular values of all light di…
Preliminary data concerning the morphology of a Calabrian Ionian margin area: Caulonia and Marina di Gioiosa canyons
2008
In the framework of the Vector National Italian Project (VulCost line), aimed to study the role of the morphology and the geology of the Ionian Calabrian margin in the coastline evolution, an oceanographic cruise was planned to collect geophysical data along two canyon systems: Caulonia and Marina di Gioiosa. The survey explored the continental shelf and slope from a depth of 15 m to more than 1150 m, using Multibeam Echosounder to investigate the seafloor topography. This work provides an outline of the erosive feature of the slope, shaped mostly by seasonal river input and by the connection to the structural and geological characteristics of the margin, made interesting by a narrow shelf …
What is the influence of parents' myopia on their children's myopic progression? A 22-year follow-up study.
2016
Purpose To study the connection between parental myopia and their children's myopia from school age to adulthood. Methods Two hundred and forty myopic schoolchildren (119 boys, 121 girls, mean age 10.9 years) with no previous spectacles for myopia were recruited to a 3-year treatment trial with different use of spectacles. Follow-ups were performed at mean ages of 13.9, 23.7 and 33.2 years for 238, 176 and 170 subjects respectively. Subjective refraction was calibrated to the spherical equivalent at corneal level (SEcor). Corneal refractive power (CR) and axial length (AL) were measured. Parental myopia was assessed with a questionnaire and the children assigned accordingly to one of three …
Sabratha. La necropoli a Nord-Est del Teatro nell'insula 8 della Regio IV e il riuso dello spazio urbano a scopo funerario
2012
The cemetery (m 29 x 39), excavated and restored by G. Caputo in the Thirties of the twentieth century, borders westwards the cardo which leads to the Early Christian churches of Regio III, and southwards the Theatre decumanus. The burial area comprises 84 tomb sub-divo, violated or with the gravestones moved. The burial types are: 1) the forma, attested by 43 specimens, 2) the case, rectangular or anthropomorphic, with 26 specimens, 3) nine cupae, characterized by a semi-cylindrical crown placed directly on the gravestones or on a base of limestone blocks, and 4) the mound, only one example. The space organization seems to follow clear rules: all the burials are in fact concentrated in the…
Correlation between Topographic Parameters Obtained by Back Surface Topography Based on Structured Light and Radiographic Variables in the Assessment…
2017
<sec><title>Study Design</title><p>Optical cross-sectional study.</p></sec><sec><title>Purpose</title><p>To study the correlation between asymmetry of the back (measured by means of surface topography) and deformity of the spine (quantified by the Cobb angle).</p></sec><sec><title>Overview of Literature</title><p>The Cobb angle is considered the gold standard in diagnosis and follow-up of scoliosis but does not correctly characterize the three-dimensional deformity of scoliosis. Furthermore, the exposure to ionizing radiation may cause harmful effects particularly during the growth stage, includi…
Anisometropia of spherical equivalent and astigmatism among myopes: a 23-year follow-up study of prevalence and changes from childhood to adulthood.
2017
Purpose To study anisometropia of spherical equivalent and astigmatism from the onset of myopia at school age to adulthood. Methods A total of 240 myopic schoolchildren (mean age 10.9 years), with no previous spectacles, were recruited during 1983–1984 to a randomized 3-year clinical trial of bifocal treatment of myopia. Examinations with subjective cyclopedic refraction were repeated 3 years later (follow-up 1) for 238 subjects and thereafter at the mean ages of 23.2 (follow-up 2) and 33.9 years (follow-up 3) for 178 and 134 subjects. After exclusions, the 102 subjects who attended all three follow-ups were included in the analyses. Corneal refractive power and astigmatism and anterior cha…
Flow-bed interactions analysis and application of automatic close range digital photogrammetric survey in a laboratory flume
2014
This paper reports on a laboratory study in which the automatic digital photogrammetric survey was applied to derive the high-resolution Digital Surface Model (DSM) of the bed topography, used for the flow-bed interactions analysis, in a large amplitude meandering laboratory flume. The analysis has been conducted with the aid of detailed data of three-dimensional flow field previously collected using the acoustic Doppler velocity profiler DOP2000. The applied surveying procedure has allowed the evaluation of the DSM with a resolution of ±0.5 mm. The detailed DSM has been compared with peculiar maps describing the flow velocity pattern (downstream and the crossstream flows) and the shear vel…
Brancati su Pirandello e il pirandellismo
2019
Nel romanzo breve "Sogno di un valzer" uscito a puntate su “Quadrivio”, dal 5 giugno al 14 agosto 1938, Vitaliano Brancati mette in scena, tra osservazione dei luoghi e rilevamento di costume, un’umanità fuori misura, continuamente in bilico tra realtà e sogno. A Caltanissetta (Nissa) la città nel cui Istituto magistrale lo scrittore, voltate le spalle alla Roma fascista, è venuto a insegnare, personaggi non appariscenti, insignificanti, che tuttavia covano desideri, si arrovellano in domande metafisiche. Prende così forma il leitmotiv delle critica al pirandellismo che più volte con ironia sottile affiora negli scritti brancatiani. Il saggio mostra come esso si intrecci con la comicità sul…
Assessment of corneal morphological changes induced by the use of daily disposable contact lenses.
2015
To assess the effect of different disposable soft contact lenses upon corneal thickness, and upon anterior and posterior corneal curvatures using a dual-Scheimpflug imaging based device.Twenty-eight young, healthy subjects wore four different types of daily disposable soft contact lenses on four different days: Dailies Total1, Proclear 1 Day, Clariti 1-Day and 1-Day Acuvue Moist. The lenses had different material and water content. Pachymetry maps and keratometry values were obtained using the Galilei G4 twice a day: one before putting the lens on and one after an eight-hour period of contact-lens wear. Measurements were also recorded without any contact lenses being worn during a day.Clari…