A non-hydrostatic pressure distribution solver for the nonlinear shallow water equations over irregular topography

We extend a recently proposed 2D depth-integrated Finite Volume solver for the nonlinear shallow wa- ter equations with non-hydrostatic pressure distribution. The proposed model is aimed at simulating both nonlinear and dispersive shallow water processes. We split the total pressure into its hydrostatic and dy- namic components and solve a hydrostatic problem and a non-hydrostatic problem sequentially, in the framework of a fractional time step procedure. The dispersive properties are achieved by incorporating the non-hydrostatic pressure component in the governing equations. The governing equations are the depth-integrated continuity equation and the depth-integrated momentum equations along the x, y and z directions. Unlike the previous non-hydrostatic shallow water solver, in the z momentum equation, we retain both the vertical local and convective acceleration terms. In the former solver, we keep only the local vertical acceleration term. In this paper, we investigate the effects of these convective terms and the possible improvements of the computed solution when these terms are not neglected in the governing equations, especially in strongly nonlinear processes. The presence of the convective terms in the verti- cal momentum equation leads to a numerical solution procedure, which is quite different from the one of the previous solver, in both the hydrostatic and dynamic steps. We discretize the spatial domain us- ing unstructured triangular meshes satisfying the Generalized Delaunay property. The numerical solver is shock capturing and easily addresses wetting/drying problems, without any additional equation to solve at wet/dry interfaces. We present several numerical applications for challenging flooding processes en- countered in practical aspects over irregular topography, including a new set of experiments carried out at the Hydraulics Laboratory of the University of Palermo

Confronto fra valutazioni del run-up fatte con un modello matematico e una formula empirica con misure di campo

La posizione planimetrica della linea di riva, soli tamente, viene determinata attraverso l\u2019uso di immagini aeree ed utilizzata pe r la ricostruzione dell\u2019evoluzione storica dei litorali. Tuttavia, le informazioni est ratte da tali immagini, descrivendo il confine istantaneo acqua-terra, consentono l\u2019indivi duazione della linea di riva esclusivamente come limite asciutto-bagnato proprio nel momento della ripresa. Per una pi\uf9 corretta localizzazione della linea di riva , \ue8 quindi necessario quantificare, oltre agli effetti di marea e di trasporto solido, gli effetti prodotti dal moto ondoso su tale posizione e in particolare il cosiddetto ru n-up. Nel presente lavoro si studia il run-up in una spia ggia naturale a debole pendenza ricadente nella Sicilia occidentale. Lo studio geom orfologico del sito precede lo studio idraulico, che partendo dalle misure di onde al largo, attraverso la loro trasposizione e la propagazione simulata con un mod ello matematico, porta alla stima delle onde sotto costa. Queste ultime sono ut ilizzate per valutare il run-up sia mediante una nota formula empirica sia utilizzando un modello numerico alla Boussinesq con una nuova condizione al contorno per la linea di riva. Il confronto dei risultati con le misure di campo mostra che i r isultati migliori si ottengono con la formula empirica, nella quale \ue8 tuttavia necessa rio calibrare i coefficienti con misure in situ

Random Wave Run-up with a Physically-based Lagrangian Shoreline Model

AbstractIn the present paper the run-up of random waves was calculated by means of a numerical method. In situ measurements based on a video imaging technique have been used for the validation of the present numerical model. The on-site run-up measurements have been carried out at Lido Signorino beach, near Marsala, Italy,along a transect, normal to the shore. A video camera and a linear array of rods have been used to obtain field data. Numerical simulations with a 1DH Boussinesq-type of model for breaking waves which takes into account the wave run-up by means of a Lagrangian shoreline model have been carried out. In such simulations random waves of given spectrum have been propagated in a numerical flume having the same beach slope of the measured transect. The comparison between registered and estimated run-up underlined an acceptable agreement. Indeed, the numerical model tends to underestimate the actual R2%, with the maximum underestimate being less than 24%, which is a reasonable error in many cases of engineering interest

Smart assistance for students and people living in a campus

Being part of one of the fastest growing area in Artificial Intelligence (AI), virtual assistants are nowadays part of everyone's life being integrated in almost every smart device. Alexa, Siri, Google Assistant, and Cortana are just few examples of the most famous ones. Beyond these off-the-shelf solutions, different technologies which allow to create custom assistants are available. IBM Watson, for instance, is one of the most widely-adopted question-answering framework both because of its simplicity and accessibility through public APIs. In this work, we present a virtual assistant that exploits the Watson technology to support students and staff of a smart campus at the University of Palermo. Some in progress results show the effectiveness of the approach we propose

Assisted labeling for spam account detection on twitter

Online Social Networks (OSNs) have become increasingly popular both because of their ease of use and their availability through almost any smart device. Unfortunately, these characteristics make OSNs also target of users interested in performing malicious activities, such as spreading malware and performing phishing attacks. In this paper we address the problem of spam detection on Twitter providing a novel method to support the creation of large-scale annotated datasets. More specifically, URL inspection and tweet clustering are performed in order to detect some common behaviors of spammers and legitimate users. Finally, the manual annotation effort is further reduced by grouping similar users according to some characteristics. Experimental results show the effectiveness of the proposed approach

Cumulative doses analysis in young trauma patients: a single-centre experience

Multidetector computed tomography (MDCT) represents the main source of radiation exposure in trauma patients. The radiation exposure of young patients is a matter of considerable medical concern due to possible long-term effects. Multiple MDCT studies have been observed in the young trauma population with an increase in radiation exposure. We have identified 249 young adult patients (178 men and 71 women; age range 14\u201340 years) who had received more than one MDCT study between June 2010 and June 2014. According to the International Commission on Radiological Protection publication, we have calculated the cumulative organ dose tissue-weighting factors by using CT-EXPO software\uae. We have observed a mean cumulative dose of about 27 mSv (range from 3 to 297 mSv). The distribution analysis is characterised by low effective dose, below 20 mSv, in the majority of the patients. However, in 29 patients, the effective dose was found to be higher than 20 mSv. Dose distribution for the various organs analysed (breasts, ovaries, testicles, heart and eye lenses) shows an intense peak for lower doses, but in some cases high doses were recorded. Even though cumulative doses may have long-term effects, which are still under debate, high doses are observed in this specific group of young patients

A new route for the preparation of flexible skin\u2013core poly(ethylene-co-acrylic acid)/polyaniline functional hybrids

Surface modification of polymeric films is a way to obtain final products with high performance for many specific and ad hoc tailored applications, e.g. in functional packaging, tissue engineering or (bio)sensing. The present work reports, for the first time, on the design and development of surface modified ethylene\u2013 acrylic acid copolymer (EAA) films with polyaniline (PANI), with the aim of inducing electrical conductivity and potentially enable the electronic control of a range of physical and chemical properties of the film surface, via a new \u2018\u2018grafting from\u2019\u2019 approach. In particular, we demonstrate that PANI was successfully polymerized and covalently grafted onto flexible EAA substrates, previously activated. The final hybrid materials and the corresponding intermediates were fully characterized via FTIR, XPS, SEM\u2013EDAX, mechanical and electrical tests. The mechanical properties of the films are not detrimentally affected by each treatment step, while a significant increase in electrical conductivity was achieved for the new hybrid materials

Comparison of the distribution of non-AIDS Kaposi's sarcoma and non-Hodgkin's lymphoma in Europe

To evaluate whether some form of mild immunosuppression may influence the geographical distribution of non-AIDS Kaposi's sarcoma (KS), we correlated incidence rates of KS and non-Hodgkin's lymphoma in individuals aged 60 or more in 18 European countries and Israel. Significant positive correlations emerged but, within highest risk countries (i.e.Italy and Israel), internal correlations were inconsistent. © 1999 Cancer Research Campaig