Studio e progettazione di un acceleratore hardware per il monitoraggio real-time di traffico RTP per applicazioni VOIP

In questa tesi si è studiato un sistema di riconoscimento e analisi di traffico RTP, protocollo utilizzato in molte applicazioni di tipo VoIP. Si è progettato un algoritmo di riconoscimento per tale protocollo, che siamo poi passati ad implementare su FPGA, realizzando un sistema trasparente alla rete in grado di riconoscere in tempo reale traffico RTP, inoltrarlo se necessario ad un sistema, e calcolarne statistiche di qualità del servizio. Il sistema è quindi stato testato per verificarne l’efficacia. In this thesis we developed a system that recognizes and analyzes RTP traffic, extensively used in VoIP applications. We conceived a transparent system (invisible to the other network devices) and we implemented it on NetFPGA. The application is able to recognize RTP packets, calculate QoS parameters and if requested send some traffic to the HostPC (where the NetFPGA is plugged). The system was tested, and test results are reported in this thesis too

Methods for the estimation of the energy stored in geothermal reservoirs

The paper analyze the problem of the estimation of the potential of geothermal reservoirs with the objective of sizing of geothermal power plants in order to reach the goal of a correct matching of renewability and economic related issues. After an analysis of the typical approaches based on the First Order Method diffused in the literature since the late 70s and of the uncertainties connected with the use of simplified approaches, that have determined general overestimation of the geothermal energy stored in the reservoirs and of the size of the plants connected to various geothermal fields, the authors discuss about possible improvements based on the combination of theoretical simplified approaches with experimental data of heat flow, taking into account not only the energy stored, but also the possibility of producing a recharge

Comparing persistence diagrams through complex vectors

The natural pseudo-distance of spaces endowed with filtering functions is precious for shape classification and retrieval; its optimal estimate coming from persistence diagrams is the bottleneck distance, which unfortunately suffers from combinatorial explosion. A possible algebraic representation of persistence diagrams is offered by complex polynomials; since far polynomials represent far persistence diagrams, a fast comparison of the coefficient vectors can reduce the size of the database to be classified by the bottleneck distance. This article explores experimentally three transformations from diagrams to polynomials and three distances between the complex vectors of coefficients.Comment: 11 pages, 4 figures, 2 table

Photonic Hall Effect in ferrofluids: Theory and Experiments

An experimental and theoretical study on the Photonic Hall Effect (PHE) in liquid and gelled samples of ferrofluids is presented. The ferrofluids are aqueous colloidal suspensions of Fe(_{2})CoO(_{4}) particles, which can be considered as anisotropic and absorbing Rayleigh scatterers. The PHE is found to be produced by the orientation of the magnetic moments of the particles, as is also the case for the Faraday effect. The dependence of the PHE with respect to the concentration of the scatterers, the magnetic field and the polarization of the incident light is measured in liquid and in gelled samples and is compared to a simple model based on the use of a scattering matrix and the single scattering approximation.Comment: 20 pages, 11 figures, submitte

Wave effects on the turning ability of an ultra large container ship in shallow water

The influence of waves on ship behaviour can lead to hazardous scenarios which put at risk the ship, the crew and the surroundings. For this reason, investigating the effect of waves on manoeuvring is of relevant interest. Waves may impair the overall manoeuvring performance of ships hence increasing risks such as collisions, which are of critical importance when considering dense traffic around harbour entrances and in unsheltered access channels. These are conditions met by Ultra Large Container Ships (ULCS) when approaching a port, e.g. in the North Sea access channels to the main sea ports of Belgium. Note that due to the large draft of ULCS and the limited water depth, shallow water effects will also influenced the ship. Thus, in such scenarios the combined effects of shallow water and waves on the ship's manoeuvring need to be studied. The present work investigates the effect of waves on the turning ability of an ULCS in shallow water. Simulations are carried out using the two time scale approach. The restricted water depth corresponds to 50% Under Keel Clearance (UKC). To gain a better insight on the forces acting on the ship, the propulsion, and the rudder behaviour in waves experimental studies were conducted. These tests were carried out in the Towing Tank for Manoeuvres in Confined Water at Flanders Hydraulics Research (in co-operation with Ghent University) with a scale model of an ULCS. Different wave lengths, wave amplitudes, ships speeds, propeller rates, and rudder angles were tested. The turning ability characteristics obtained from simulations in waves and calm water are presented, and discussed

Software Defined Networking for resource allocation and monitoring: virtualization and hardware acceleration

Le reti di telecomunicazioni sono presenti in modo sempre più pervasivo nella nostra vita di tutti i giorni, e sempre più persone le usano per un numero crescente di operazioni. Gli utenti hanno aspettative sempre maggiori per le performance della rete, usandole per diverse applicazioni, con livelli sempre più alti di interattività. Le reti quindi si trovano ad avere non solo traffici sempre maggiori, e differenti pattern di traffico, ma anche una domanda crescente in termini di prestazioni offerte. In questo scenario, diviene di fondamentale importanza identificare le aree dove apportare modifiche, e le tecnologie da sfruttare e implementare in questo processo. In questa tesi, vengono esplorate le possibilità offerte dalle nuove tecnologie di virtualizzazione: nuovi approcci che permettono di virtualizzare le reti, vedendole come risorse fisiche sulle quali costruire funzioni che possono essere independenti dall’infrastruttura sottostante, esattamente come già accade con i sistemi operativi per i computer, che offrono all’utente una versione virtualizzata delle risorse hardware disponibili. In particolare, in questa tesi, ci si concentra sul concetto di Software Defined Netowrking, e su come questo approccio possa essere usato nella pratica per fornire risposte ad alcune questioni ancora aperte. Allo stesso tempo, riteniamo che al fine di operare su reti ad alte prestazioni e con throughput di rilievo, ci sia bisogno di basare le considerazioni, le decisioni da prendere, su dati il più possibile precisi, forniti da strumenti in grado di raggiungere alte risoluzioni. Questo tipo di azioni richiedono l’utilizzo di hardware ad alte prestazioni per la misura e il monitoraggio, e anche questo aspetto è stato tenuto in considerazione in questo percorso di ricerca Communication networks are more and more present in everyday life, as more and more people use them for an increasing number of operations. Users have growing expectations about network performances, while they use them with different applications, with increasing levels of interactivity. Networks not only have to deal with higher traffics, different traffic patterns, new demands, but also with higher requirements for performing operations. In this scenario, it becomes of fundamental importance to identify novel promising technologies, and understand when, where and how to deploy them in the most effective ways. In this thesis, we explore the possibilities offered by virtualization technologies: novel approaches that allow to virtualize networks, seeing them as general physical resources on which to run functions that can be separated from the real underlying infrastructure, just as it happens with the well-known operating systems for computers, that offer to the user a virtualizes version of the pool of resources available. In particular, in this thesis, we focused on studying Software Defined Networking, and how such technology can be deployed to give answers to some open issues in networking. At the same time, we have always kept in mind that in order to perform high performance operations on networks that experience high throughputs, we need to base our calculations and decisions on precise data, and have tools that allow to reach higher precisions and resolutions. These kinds of actions require the deployment of high performing hardware for measuring and monitoring, and we have kept also this aspect in consideration in our researc

Abdominal ultrasound to analyze the voiding of the stomach and of the small gut

L’emploi de l’échographie abdominale (EA) pour visualiser les vidanges et les reflux reste balbutiant. Ce travail inclut 234 adultes et propose une méthodologie d’étude de la motricité gastroduodénojéjuno- iléale avec EA, élastométrie hépatique et manoeuvres ostéopathiques. Un reflux duodénopancréatique ou duodénobiliaire - qui suggère une hypotonie du sphincter d’Oddi - est constaté dans 44,9 % des cas ; Un reflux jéjunoduodénal est visualisable une fois sur trois ; Un reflux gastro-oesophagien s’observe chez 21,8% des sujets ; Le pourcentage de patients avec un frein iléal atteint 32,7 % ; Chez certains patients (33,0 %), la pression duodénale induit un spasme paradoxal du premier jéjunum (hypertonie jéjunale haute) ; Dans 53,22 % des cas, les gaz et des matières ne progressent pas dans les anses jéjunales qui apparaissent distendues (hypotonie jéjunale globale). Les patients avec une hypotonie du sphincter d’Oddi souffrent plus d’herpès/aphtes (68,6 % versus 41,9 ; p<0,001). Le reflux jéjuno-duodénal est plus fréquent (44,3 % versus 24,4 % ; p<10-5). Les patients avec hypertonie jéjunale haute présentent plus fréquemment un surpoids (77,3 kg ± 19,0 versus 63,1 kg ± 12,5 ; p<10-9), un frein iléal (53,8 % versus 22,1 ; p<10-9) ou un reflux gastro-oesophagien (23,1% versus 11,5 ; p<10-7). Les plus mauvais résultats obtenus par l’élastométrie hépatique après pression duodénale (10,3 kPA ± 5,4 versus 5,9 kPA ± 2,55 ; p<10-9) s’observent chez les patients avec une hypotonie du sphincter d’Oddi et une hypotonie jéjunale globale (30,3 %). EA et ostéopathie constituent un nouvel outil d’analyse de la motricité digestive. Leur place et les mesures de référence restent à spécifier.Abdominal ultrasound (AU) is not currently used to study the motility of the gut. This work includes 234 adults and suggests a new methodology - involving AU, liver elastometry and osteopathic manoeuvers – to study the motility of intra-abdominal organs. A duodenopancreatic or a duodenobiliary reflux – which suggests an hypotonia of the Oddi’s sphincter was identified in 44.9% of patients; The practitioner found a jejunoduodenal reflux in one patient out of three; 32.7% of patients presented with an ileal break (inflated ileocecal junction); A slight duodenal pressure induced a paradoxical spasm of the first jejunum in 33.0% of the cases (spasm of the first jejunal loop); In 53.22% of the cases, lack of peristalsis precludes any progression of gas or food in the gut (global jejunal hypotonia). Patients with hypotonia of the Oddi’s sphincter present more frequently with herpes (68.6% versus 41.9; p<0.001). Jejunoduodenal reflux was more frequent (44.3% versus 24.4%; p<10-5). Patients with a spasm of the first jejunal loop present more frequently with overweight (77.3 kg ± 19.0 versus 63.1 kg ± 12.5; p<10-9), ileal break (53.8% versus 22.1; p<10-9) or gastrooesophageal reflux (23.1% versus 11.5; p<10-7). Liver elasticity was severely hindered in patients with an hypotonia of the Oddi’s sphincter associated with a global jejunal hypotonia (10.3 kPA ± 5.4 versus 5.9 kPA ± 2.55 after a slight duodenal pressure; p<10-9) which is diagnosed in 33.0% of the cases. EA with osteopathy open a new way to investigate stomach and gut motility. Their uses and standards remain to be defined with additional studies

Potential Biomarkers of thyroid neoplasia: the impact of proteomics analysis in the diagnosis.

Fine-needle aspiration cytology (FNA) is the most important tool to correctly address a thyroid lesion. Thyroid cancers account for about 5% of all lesions. A correct diagnosis may be difficult using FNA. Thyroid biomarkers help to better characterized thyroid lesions. Among the new techniques, proteomics , since 2002, has been increasingly used. In this thesis we describe the results obtained by the proteomic analysis of thyroid FNA to detect potential biomarkers for thyroid neoplasia and its impact in clinical management of thyroid malignancies