316 research outputs found
Seismic Response of a Platform-Frame System with Steel Columns
Timber platform-frame shear walls are characterized by high ductility and diffuse energy dissipation but limited in-plane shear resistance. A novel lightweight constructive system composed of steel columns braced with oriented strand board (OSB) panels was conceived and tested. Preliminary laboratory tests were performed to study the OSB-to-column connections with self-drilling screws. Then, the seismic response of a shear wall was determined performing a quasi-static cyclic-loading test of a full-scale specimen. Results presented in this work in terms of force-displacement capacity show that this system confers to shear walls high in-plane strength and stiffness with good ductility and dissipative capacity. Therefore, the incorporation of steel columns within OSB bracing panels results in a strong and stiff platform-frame system with high potential for low- and medium-rise buildings in seismic-prone areas
Analytical and experimental FWHM of a gamma camera: theoretical and practical issues
It is well known that resolution on a gamma camera varies as a
function of distance, scatter and the camera\u2019s characteristics (collimator type,
crystal thickness, intrinsic resolution etc). Manufacturers frequently provide only
a few pre-calculated resolution values (using a line source in air, 10\u201315 cm from
the collimator surface and without scattering). However, these are typically not
obtained in situations resembling a clinical setting. From a diagnostic point of view,
it is useful to know the expected resolution of a gamma camera at a given distance
from the collimator surface for a particular setting in order to decide whether it is
worth scanning patients with \u201csmall lesion\u201d or not. When dealing with absolute
quantification it is also mandatory to know precisely the expected resolution and its
uncertainty in order to make appropriate corrections.
Aim. Our aims are: to test a novel mathematical approach, the cubic spline interpolation,
for the extraction of the full width at half maximum (FWHM) from the
acquisition of a line source (experimental resolution) also considering measurement
uncertainty; to compare it with the usually adopted methods such as the gaussian
approach; to compare it with the theoretical resolution (analytical resolution) of a
gamma camera at different distances; to create a web-based educational program
with which to test these theories.
Methods. Three mathematical methods (direct calculation, global interpolation using
gaussian and local interpolation using splines) for calculatingFWHMfroma line
source (planar scintigraphy) were tested and compared. A NEMA Triple Line Source
Phantom was used to obtain static images both in air and with different scattering
levels. An advanced, open-source software (MATLAB/Octave and PHP based) was
created \u201cad hoc\u201d to obtain and compareFWHMvalues and relative uncertainty.
Results and Conclusion. Local interpolation using splines proved faster and more
reliable than the usually-adopted Gaussian interpolation. The proposed freely available
software proved effective in assessing bothFWHMand its uncertainty
GIS-BIM Interoperability for Regeneration of Transurban Areas
open3noIn order to manage analysis and project processes at a territorial, urban and architectural scale, linking information to metric data is an increasingly important topic.
At a geographic and cartographic stage, the function of storing, managing and viewing data and information is performed by GIS (Geographic Information Systems), where vector features as points, lines, polygons are gathered in layers connected to an attribute table.
In a similar way, when scale factor increases, for buildings and other engineering works there is a growing necessity to preserve data or attributes together with the features where they belong. For this purpose, a major role is played by BIM (Building Information Modeling), a modelling process in which the parts of a building are hierarchically organized and every feature is connected to an information table containing all data useful for the ongoing working process or for managing the life cycle of the modelled building or infrastructure.
While the two systems are similar in concept, at the moment they suffer lack of mutual communication, especially in conveying informations from a platform to another. Studying relationships and possible connections between different data storage environments like GIS and BIM is one of the research topics of DATA – Developing Abandoned Transurban Areas, a research project now in progress at University of Padova, involving Departments of Civil, Architectural and Environmental Engineering and Industrial Engineering. The main goal of the project is to design pilot regeneration scenarios for wasted or underused places,
focusing on a part of the western peri-urban area of Padova marked by the overlapping of partially abandoned industrial or commercial buildings, transport infrastructures like a ring road and a railway, residential fabric and green or agricultural land. Among DATA key features there is a multi-scale approach: in a framework where urban peripheries are considered a relation system between a city and the surrounding territory, the project aims to combine the
methods of urban and territorial analysis with a design concept in which industrial landmarks or empty spaces become the core of possible urban transformations.
Therefore, starting from data mining and management related to the areas of interest, procedures for GIS to BIM data transfer are surveyed and implemented; then, the buildings, facilities and building complex involved in scenarios design will be modelled in detail, and relevant building-scale information will be
added. At the moment, within the project, a pipeline to convert a GIS map of the buildings in our area of interest into a BIM 3D model provided with all the information of the GIS layer has been developed. Then, when the BIM model is modified, its updated attributes can be taken back to the GIS level.
The aim of this paper is to describe the workflow for GIS-BIM interoperability in DATA project, results achieved at the moment and future goals and applications.openDavide Barbato, Guglielmo Pristeri, Massimo De MarchiBarbato, Davide; Pristeri, Guglielmo; DE MARCHI, Massim
Oversampling errors in multimodal medical imaging are due to the Gibbs effect
To analyse multimodal 3-dimensional medical images, interpolation is required
for resampling which - unavoidably - introduces an interpolation error. In this
work we consider three segmented 3-dimensional images resampled with three
different neuroimaging software tools for comparing undersampling and
oversampling strategies and to identify where the oversampling error lies. The
results indicate that undersampling to the lowest image size is advantageous in
terms of mean value per segment errors and that the oversampling error is
larger where the gradient is steeper, showing a Gibbs effect
Cluster-based Vibration Analysis of Structures with GSP
This article describes a divide-and-conquer strategy suited for vibration monitoring applications. Based on a low-cost embedded network of microelectromechanical accelerometers, the proposed architecture strives to reduce both power consumption and computational resources. Moreover, it eases the sensor deployment on large structures by exploiting a novel clustering scheme, which
consists of unconventional and nonoverlapped sensing configurations. Signal processing techniques for inter- and intracluster data assembly are introduced to allow for a fullscale assessment of the structural integrity. More specifically, the capability of graph signal processing is adopted for the first time in vibration-based monitoring scenarios to capture the spatial relationship between acceleration data. The experimental validation, conducted on a steel beam perturbed with additive mass, reveals high accuracy in damage detection tasks. Deviations in spectral content and mode shape envelopes are correctly revealed regardless of environmental factors and operational uncertainties. Furthermore, an additional key advantage of the implemented architecture relies on its compliance with blind modal investigations, an approach that favors the implementation of autonomous smart monitoring systems
Land grab, cooperazione internazionale e geografia: riflessioni per la ricerca e l’azione
Intensive simulation training on urological mini-invasive procedures using Thiel-embalmed cadavers: The IAMSurgery experience
Introduction: The objective of the study was to evaluate the benefits perceived by the use of cadaver models by IAMSurgery attendees and to define indications to standardize future similar training camps. Materials and methods: A 25-item survey was distributed via e-mail to all the participants of previous training courses named as "Urological Advanced Course on Laparoscopic Cadaver Lab" held at the anatomy department of the University of Malta, for anonymous reply. Participants were asked to rate the training course, the Thiel's cadaveric model, and make comparison with other previously experienced simulation tools. Results: The survey link was sent to 84 attendees, with a response rate of 47.6% (40 replies). There was improvement in the median self-rating of the laparoscopic skills before and after the training camp with a mean difference of 0.55/5 points in the post-training skills compared to the basal (p < 0.0001). The 72.2% of the urologists interviewed considered Thiel's HCM better than other training methods previously tried, while five urologists (27.8%) considered it equal (p = 0.00077). Globally, 77.5% (31) of attendees found the training course useful, and 82.5% (33) would advise it to colleagues. Conclusions: Thiel's fixed human cadaveric models seem to be ideal for training purposes, and their use within properly structured training camps could significantly improve the surgical skills of the trainees. An important future step could be standardization of the training courses using cadavers, and their introduction into the standardized European curriculum.Publisher's versionArchivio Italiano di Urologia AndrologiaOpen Access5 page
Alternative Design Methodologies for the Next Generation Logic Switch (invited paper)
Next generation logic switch devices are ex- pected to rely on radically new technologies mainly due to the increasing difficulties and limitations of state-of-the-art CMOS switches, which, in turn, will also require innovative design methodologies that are distinctly different from those used for CMOS technologies. In this paper, three alternative emerging technologies are showcased in terms of their re- quirements for design implementation and in terms of poten- tial advantages. First, a CMOS evolutionary approach based on vertically-stacked gate-all-around Si nanowire FETs is discussed. Next, an alternative design methodology based on ambipolar carbon nanotube FETs is presented. Finally, a novel approach based on the recently discovered memristive devices is presented, offering the possibility of combining memory and logic functions
The virucidal potential effects of violet-blue light on influenza D virus
Influenza D virus (IDV) is a novel influenza virus, first isolated from swine with influenza-like symptoms in the USA in 2011. To date, IDV circulation has been reported in various animal species such as cattle, pigs, horses with the ability to expand its range of hosts. UV radiation has been widely used for the disinfection of various sources such as water, air, and surfaces, especially in places at greater risk of contamination by viruses and bacteria, such as hospitals and health facilities. The aim of this study was to evaluate the potential virucidal effect of a violet-blue light against IDV. Viral suspension of IDV was exposed to a violet-blue light (405 nm) for different times (radiant exposures): 22 min and 30 s (5.4 J/cm2), 45 min (10.8 J/cm2), 90 min (21.6 J/cm2), 180 min (43.2 J/cm2), and 360 min (86.4 J/cm2), and different temperatures (room temperature, 4 and 37 °C). At the end of exposure, virus titration was performed on MDCK cells. After violet-blue light exposure, a viral titre reduction proportional to exposure time was observed: 0.228 log10 after 22 min and 30 s, 0.668 log10 after 45 min, 0.940 log10 after 90 min, 1.375 log10 after 180 min and 2.293 log10 after 360 min. Differences were observed among temperatures of exposure, with the greatest virucidal effect observed at room temperature. As reported for other respiratory viruses, this violet-blue light can potentially be used to reduce IDV spread in potentially hotspot areas for animals and humans
Randomised phase 3 open-label trial of first-line treatment with gemcitabine in association with docetaxel or paclitaxel in women with metastatic breast cancer: a comparison of different schedules and treatments
BACKGROUND: This open-label study compared docetaxel/gemcitabine vs. paclitaxel/gemcitabine and a weekly (W) vs. 3-weekly (3 W) schedule in metastatic breast cancer (MBC). METHODS: Patients relapsed after adjuvant/neoadjuvant anthracycline-containing chemotherapy were randomized to: A) gemcitabine 1000 mg/m(2) Day 1,8 + docetaxel 75 mg/m(2) Day 1 q3W; B) gemcitabine 1250 mg/m(2) Day 1,8 + paclitaxel 175 mg/m(2) Day 1 q3W; C) gemcitabine 800 mg/m(2) Day 1,8,15 + docetaxel 30 mg/m(2) Day 1,8,15 q4W; D) gemcitabine 800 mg/m(2) Day 1,15 + paclitaxel 80 mg/m(2) Day 1,8,15 q4W. Primary endpoint was time-to-progression (TTP). Secondary endpoints were overall survival (OS) and overall response rate (ORR). RESULTS: Interim analysis led to accrual interruption (241 patients enrolled of 360 planned). Median TTP (months) was 8.33 (95% CI: 6.19-10.16) with W and 7.51 (95% CI: 5.93-8.33) with 3 W (p=0.319). No differences were observed in median TTP between docetaxel and paclitaxel, with 85.6% and 87.0% of patients progressing, respectively. OS did not differ between regimens/schedules. ORR was comparable between regimens (HR: 0.882; 95% CI: 0.523-1.488; p=0.639), while it was significantly higher in W than in the 3 W (HR: 0.504; 95% CI: 0.299-0.850; p=0.010) schedule. Grade 3/4 toxicities occurred in 69.2% and 71.9% of patients on docetaxel and paclitaxel, and in 65.8% and 75.2% in W and 3 W. CONCLUSIONS: Both treatment regimens showed similar TTP. W might be associated with a better tumour response compared with 3 W. TRIAL REGISTRATION: Clinicaltrial.gov ID NCT0023689
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