187 research outputs found

    Seismic Response of a Platform-Frame System with Steel Columns

    Get PDF
    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

    GIS-BIM Interoperability for Regeneration of Transurban Areas

    Get PDF
    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

    Analytical and experimental FWHM of a gamma camera: theoretical and practical issues

    Get PDF
    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

    Oversampling errors in multimodal medical imaging are due to the Gibbs effect

    Get PDF
    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

    Get PDF
    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

    Intensive simulation training on urological mini-invasive procedures using Thiel-embalmed cadavers: The IAMSurgery experience

    Get PDF
    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)

    Get PDF
    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


    Get PDF
    INTRODUCTION AND OBJECTIVES: To determinate bene\ufb01ts of the association of local anaesthetic wounds in\ufb01ltration and US-TAPblock with ropivacaine on postoperative pain, early recovery and hospital stay in patients undergoing robot assisted radical prostatectomy (RARP). METHODS: The study is double-blinded randomized controlled trial. Our hypothesis was that the association of wound in\ufb01ltration and US-TAP block with Ropivacaine would decrease immediate postoperative pain and opioids use. Primary outcomes included postoperative pain and opioids demand during the hospital stay. Secondary outcomes were nausea/vomiting rate, stool passing time, use of pro-kinetics, length of hospital stay and 30-days readmission to the hospital for pain or other US-TAP-block related complications RESULTS: A total of 100 patients who underwent RARP were eligible for the analysis; 57 received the US-TAP block with 20 ml of 0.35% Ropivacaine (US-TAP-block group) and 43 did not receive USTAP block (no-US-TAP group). All the patients received the local wound anaesthetic in\ufb01ltration with 20 ml of 0.35% Ropivacaine. USTAP block group showed a decreased mean NRS (2.7vs1.8; p[0.04) and reduced use of opioid (8 vs 2; p[0.01) in the \ufb01rst 24 h. Moreover, we found a shorter mean LOS (4.7 vs 4.2; p[ 0.04) with a reduced use of pro-kinetics during the hospital stay (31 vs 12; p&lt;0.001). No US-TAP-block related complications to were reported. CONCLUSIONS: Association of anaesthetic wound in\ufb01ltration and US-TAP block with Ropivacaine as part of a multimodal analgesic regimen can be safely offered to patients undergoing RARP and ePLND. It improves the immediate post-operative pain control, reducing opioids administration and is associated to a decreased use of pro-kinetics and shorter hospital stay

    The preoperative serum ratio of total prostate specific antigen (PSA) to free testosterone (FT), PSA/FT index ratio, and prostate cancer. Results in 220 patients undergoing radical prostatectomy

    Get PDF
    Objectives: To evaluate associations of preoperative total prostate specific antigen (PSA) to free testosterone (FT), the PSA/FT index ratio, with features of pathology prostate cancer (PCA) and to investigate its prognostic potential in clustering the PCA population. Patients and methods: After excluding criteria, the records of 220 patients who underwent radical prostatectomy (RP) were retrospectively reviewed. Serum samples of PSA, total testosterone (TT) and FT were collected at 8.00 A.M., one month after biopsies and before RP. The PSA/FT ratio was computed in the population of patients who were clustered in groups according to ranking intervals of the PSA/FT ratio which identified at least 4 clusters which were coded as A, B, C, and D. The independent associations of the PSA/FT index ratio were assessed by statistical methods and a two-sided P &lt; 0.05 was considered to indicate statistical significance. Results: TT correlated to FT which was a significant predictor of PSA in the population of patients who were subsequently clustered, according to increasing interval values of the PSA/FT index ratio, in groups that showed a stronger linear association of FT with PSA. The PSA/FT index ratio significantly associated with pathology features of prostate cancer such as pathology Gleason score (pGS), invasion of the seminal vesicles (pT3b), proportion of positive cores (P+) and proportion of cancer involving the volume of the prostate. In the population of patients, TT, PSA/FT index ratio and P+ independently associated with pGS 65 7 and pT3b; moreover, the odds ratio (OR) of the PSA/FT index ratio resulted 9.11 which was stronger than TT (OR = 1.11) and P+ (OR = 8.84). In the PCA population, TT, PSA/FT index ratio and P+ also independently associated with pT3b PCA; interestingly, the OR of PSA/FT index resulted 54.91 which was stronger than TT (OR = 1.31) and P+ (26.43). Conclusions: Preoperative PSA/FT index ratio is an independent strong factor which directly associates with aggressive features of pathology PCA; moreover, it might express prognostic potential for clustering the patient population in risk classes. Confirmatory studies are required
    • …