43 research outputs found

    New design methodologies for microwave oscillators based on negative impedance. Study and development of the solution space concept

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    The topic of this thesis concern the study of new design methodologies for microwave oscillators based on negative impedance and LC resonant circuits. For this class of systems, it is not ordinary possibile to predict the stationary behaviour of the circuit without use non linear analysis methodologies, but these are very e complicated and not very helpful for the design. Indeed, for microwave circuits, the design technique is that of reflection parameters "S" that describe with accuracy only linear systems and shaped them in response to small signal conditions. Therefore the only way to design a good oscillator is through experience and try and error procedures. By Developping a CAD tool that allows to represent in graphical form all possibile solutions (The Solution Space) for which an amplifier and two passive networks (feedback and loads) are able to give a negative impedance looking by other port, a new design methodology has been presented. This methodology use only S small signal parameters and allows to guarantee the start-up for a given frequency when the other port is colsed with a proper LC circuit, and moreover is able to predict the behaviour of the system in steady state. Then became easily possibile to design the system in order to maximize the output power and reduce the phase noise. The proposed methodology is then successfully used in the design of a 38GHz VCO. ------------------------------------------------------------------------------------------------------------------------ L’oggetto di questa tesi è lo studio di nuove metodologie di progetto per oscillatori a microonde costituiti da un blocco di impedenza negativa e un circuito risonante LC. Per tale classe di sistemi la difficoltà nella procedura di progettazione consiste nel non aver ancora trovato una chiave che permettesse di prevederne il comportamento a regime senza l’utilizzo di metodi di analisi non lineare, notoriamente molto complicati e poco utili per il progetto. Infatti, per i circuiti a microonde, la tecnica universalmente adottata è quella dell’utilizzo dei parametri di riflessione “S” che descrivono con veridicità solamente sistemi lineari e modellati in risposta a condizioni di piccolo segnale. Non esistono quindi metodologie per gli oscillatori che vengono progettati secondo esperienza procedure del tipo try and error. Sviluppando al calcolatore un tool che permette la rappresentazione grafica dell’insieme delle soluzioni (Spazio delle Soluzioni) per cui un sistema costituito da amplificatore e reti passive di reazione e di carico possono generare una resistenza negativa ad una porta si è messa appunto una metodologia che non solo garantisce le condizioni di innesco del sistema quando la restante porta viene chiusa da un opportuno circuito risonante, di cui è possibile estrarre le caratteristiche, ma anche di prevedere unicamente utilizzando i parametri a piccolo segnale, il comportamento del sistema a largo segnale e di progettare l’oscillatore in maniera scientifica secondo le specifiche desiderate. La metodologia proposta viene quindi applicata con successo al progetto di un VCO a 38GHz

    Toward a centralized data management center for integrated landslide monitoring in Emilia Romagna Region (Italy)

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    In Emilia Romagna Region, slope monitoring systems have become more widely used for hazard and risk management. However, they are generally non-interoperable. Moreover dispersion of monitoring data in several local databases have made data sharing among the involved institutional actors quite laborious and often untimely. A centralized database and a web-based portal that integrate infor- mation derived by different types of slope monitoring systems has been developed. The paper illustrates the specific features of the developed “SensorNet” and provides examples of its use for visualizing and analyzing in an integrated manner data from different monitoring systems. In perspective it could serve as an every-day operational tool for a timely reporting of landslide monitoring data for surveillance and warning purposes

    Fully Band Resolved Scattering Rate in MgB2 Revealed by Nonlinear Hall Effect and Magnetoresistance Measurements

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    We have measured the normal state temperature dependence of the Hall effect and magnetoresistance in epitaxial MgB2 thin films with variable disorders characterized by the residual resistance ratio RRR ranging from 4.0 to 33.3. A strong nonlinearity of the Hall effect and magnetoresistance have been found in clean samples, and they decrease gradually with the increase of disorders or temperature. By fitting the data to the theoretical model based on the Boltzmann equation and ab initio calculations for a four-band system, for the first time, we derived the scattering rates of these four bands at different temperatures and magnitude of disorders. Our method provides a unique way to derive these important parameters in multiband systems.Comment: 4 pages, 4 figure

    Fusing Acoustic Ranges and Inertial Measurements in AUV Navigation: the Typhoon AUV at CommsNet13 Sea Trial

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    The paper presents some experimental results of autonomous underwater navigation, based on the fusion of acoustic and inertial measurements. The work is in the framework of the Thesaurus project, funded by the Tuscany Region, aiming at developing techniques for systematic exploration of marine areas of archaeological interest through a team of Autonomous Underwater Vehicles (AUVs). The test was carried out with one Typhoon vehicle, a 300m depth rated AUV with acoustic communication capabilities, during the CommsNet13 experiment, organized and scientifically coordinated by the NATO S&T Org. Ctr. for Maritime Research and Experimentation (CMRE, formerly NURC), with the participation of several research institutions. The fusion algorithm is formally casted into an optimal stochastic filtering problem, where the rough estimation of the vehicle position, velocity and attitude, are refined by using the depth measurement, the relative measurements available on the acoustic channel and the vehicle surge speed

    Segmental transverse colectomy. Minimally invasive versus open approach: results from a multicenter collaborative study

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    none65noThe role of minimally invasive surgery in the treatment of transverse colon cancer is still controversial. The aim of this study is to investigate the advantages of a totally laparoscopic technique comparing open versus laparoscopic/robotic approach. Three hundred and eighty-eight patients with transverse colon cancer, treated with a segmental colon resection, were retrospectively analyzed. Demographic data, tumor stage, operative time, intraoperative complications, number of harvested lymph nodes and recovery outcomes were recorded. Recurrences and death were also evaluated during the follow-up. No differences were found between conventional and minimally invasive surgery, both for oncological long-term outcomes (recurrence rate p = 0.28; mortality p = 0.62) and postoperative complications (overall rate p = 0.43; anemia p = 0.78; nausea p = 0.68; infections p = 0.91; bleeding p = 0.62; anastomotic leak p = 0.55; ileus p = 0.75). Nevertheless, recovery outcomes showed statistically significant differences in favor of minimally invasive surgery in terms of time to first flatus (p = 0.001), tolerance to solid diet (p = 0.017), time to first mobilization (p = 0.001) and hospital stay (p = 0.004). Compared with laparoscopic approach, robotic surgery showed significantly better results for time to first flatus (p = 0.001), to first mobilization (p = 0.005) and tolerance to solid diet (p = 0.001). Finally, anastomosis evaluation confirmed the superiority of intracorporeal approach which showed significantly better results for time to first flatus (p = 0.001), to first mobilization (p = 0.003) and tolerance to solid diet (p = 0.001); moreover, we recorded a statistical difference in favor of intracorporeal approach for infection rate (p = 0.04), bleeding (p = 0.001) and anastomotic leak (p = 0.03). Minimally invasive approach is safe and effective as the conventional open surgery, with comparable oncological results but not negligible advantages in terms of recovery outcomes. Moreover, we demonstrated that robotic approach may be considered a valid option and an intracorporeal anastomosis should always be preferred.noneMilone, Marco; Degiuli, Maurizio; Velotti, Nunzio; Manigrasso, Michele; Vertaldi, Sara; D'Ugo, Domenico; De Palma, Giovanni Domenico; Dario Bruzzese, Giuseppe Servillo, Giuseppe De Simone, Katia Di Lauro, Silvia Sofia, Marco Ettore Allaix, Mario Morino, Rossella Reddavid, Carlo Alberto Ammirati, Stefano Scabini, Gabriele Anania, Cristina Bombardini, Andrea Barberis, Roberta Longhin, Andrea Belli, Francesco Bianco, Giampaolo Formisano, Giuseppe Giuliani, Paolo Pietro Bianchi, Davide Cavaliere, Leonardo Solaini, Claudio Coco, Gianluca Rizzo, Andrea Coratti, Raffaele De Luca, Michele Simone, Alberto Di Leo, Giovanni De Manzoni, Paola De Nardi, Ugo Elmore, Riccardo Rosati, Andrea Vignali, Paolo Delrio, Ugo Pace, Daniela Rega, Antonio Di Cataldo, Giovanni Li Destri, Annibale Donini, Luigina Graziosi, Andrea Fontana, Michela Mineccia, Sergio Gentilli, Manuela Monni, Mario Guerrieri, Monica Ortenzi, Francesca Pecchini, Micaela Piccoli, Italy. Corrado Pedrazzani, Giulia Turri, Sara Pollesel, Franco Roviello, Marco Rigamonti, Michele Zuolo, Mauro Santarelli, Federica Saraceno, Pierpaolo Sileri Giuseppe Sigismondo Sica, Luigi Siragusa Salvatore Pucciarelli, Matteo ZuinMilone, Marco; Degiuli, Maurizio; Velotti, Nunzio; Manigrasso, Michele; Vertaldi, Sara; D'Ugo, Domenico; De Palma, Giovanni Domenico; Dario Bruzzese, Giuseppe Servillo, Giuseppe De Simone, Katia Di Lauro, Silvia Sofia, Marco Ettore Allaix, Mario Morino, Rossella Reddavid, Carlo Alberto Ammirati, Stefano Scabini, Gabriele Anania, Cristina Bombardini, Andrea Barberis, Roberta Longhin, Andrea Belli, Francesco Bianco, Giampaolo Formisano, Giuseppe Giuliani, Paolo Pietro Bianchi, Davide Cavaliere, Leonardo Solaini, Claudio Coco, Gianluca Rizzo, Andrea Coratti, Raffaele De Luca, Michele Simone, Alberto Di Leo, Giovanni De Manzoni, Paola De Nardi, Ugo Elmore, Riccardo Rosati, Andrea Vignali, Paolo Delrio, Ugo Pace, Daniela Rega, Antonio Di Cataldo, Giovanni Li Destri, Annibale Donini, Luigina Graziosi, Andrea Fontana, Michela Mineccia, Sergio Gentilli, Manuela Monni, Mario Guerrieri, Monica Ortenzi, Francesca Pecchini, Micaela Piccoli, Italy. Corrado Pedrazzani, Giulia Turri, Sara Pollesel, Franco Roviello, Marco Rigamonti, Michele Zuolo, Mauro Santarelli, Federica Saraceno, Pierpaolo Sileri Giuseppe Sigismondo Sica, Luigi Siragusa Salvatore Pucciarelli, Matteo Zui

    Guidebook 'How to develop a Sustainable Energy and Climate Action Plan (SECAP)'

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    The Covenant of Mayors for Climate and Energy (CoM) is an ambitious initiative for local climate and energy actions. This document provides signatories with a set of methodological principle, procedures and best practices to develop their SECAP. The Part 1 of this document relates to the SECAP process; while Part 2gives an insight on the elaboration of municipality assessments (BEI and RVA), finally Part 3 describes technical issues, measures and policies that can be implemented at local level.JRC.C.2-Energy Efficiency and Renewable

    Colorectal Cancer Stage at Diagnosis Before vs During the COVID-19 Pandemic in Italy

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    IMPORTANCE Delays in screening programs and the reluctance of patients to seek medical attention because of the outbreak of SARS-CoV-2 could be associated with the risk of more advanced colorectal cancers at diagnosis. OBJECTIVE To evaluate whether the SARS-CoV-2 pandemic was associated with more advanced oncologic stage and change in clinical presentation for patients with colorectal cancer. DESIGN, SETTING, AND PARTICIPANTS This retrospective, multicenter cohort study included all 17 938 adult patients who underwent surgery for colorectal cancer from March 1, 2020, to December 31, 2021 (pandemic period), and from January 1, 2018, to February 29, 2020 (prepandemic period), in 81 participating centers in Italy, including tertiary centers and community hospitals. Follow-up was 30 days from surgery. EXPOSURES Any type of surgical procedure for colorectal cancer, including explorative surgery, palliative procedures, and atypical or segmental resections. MAIN OUTCOMES AND MEASURES The primary outcome was advanced stage of colorectal cancer at diagnosis. Secondary outcomes were distant metastasis, T4 stage, aggressive biology (defined as cancer with at least 1 of the following characteristics: signet ring cells, mucinous tumor, budding, lymphovascular invasion, perineural invasion, and lymphangitis), stenotic lesion, emergency surgery, and palliative surgery. The independent association between the pandemic period and the outcomes was assessed using multivariate random-effects logistic regression, with hospital as the cluster variable. RESULTS A total of 17 938 patients (10 007 men [55.8%]; mean [SD] age, 70.6 [12.2] years) underwent surgery for colorectal cancer: 7796 (43.5%) during the pandemic period and 10 142 (56.5%) during the prepandemic period. Logistic regression indicated that the pandemic period was significantly associated with an increased rate of advanced-stage colorectal cancer (odds ratio [OR], 1.07; 95%CI, 1.01-1.13; P = .03), aggressive biology (OR, 1.32; 95%CI, 1.15-1.53; P < .001), and stenotic lesions (OR, 1.15; 95%CI, 1.01-1.31; P = .03). CONCLUSIONS AND RELEVANCE This cohort study suggests a significant association between the SARS-CoV-2 pandemic and the risk of a more advanced oncologic stage at diagnosis among patients undergoing surgery for colorectal cancer and might indicate a potential reduction of survival for these patients

    Re-Nuca: Boosting CMP performances through block replication

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    Abstract— Chip Multiprocessor (CMP) systems have become the reference architecture for designing micro-processors, thanks to the improvements in semiconductor nanotechnology that have continuously provided a crescent number of faster and smaller per-chip transistors. The interests for CMPs grew up since classical techniques for boosting performance, e.g. the increase of clock frequency and the amount of work performed at each clock cycle, can no longer deliver to significant improvement due to energy constrains and wire delay effects. CMP systems generally adopt a large last-level-cache (LLC) (typically, L2 or L3) shared among all cores, and private L1 caches. As the miss resolution time for private caches depends on the response time of the LLC, which is wire-delay dominated, performance are affected by wire delay. NUCA caches have been proposed for single and multi core systems as a mechanism for tolerating wire-delay effects on the overall performance. In this paper, we introduce a novel NUCA architecture, called Re-NUCA, specifically suited for (but not limited to) CMPs in which cores are placed at different sides of the shared cache. The idea is to allow shared blocks to be replicated inside the shared cache, in order to avoid the limitations to performance improvements that arise in classical D-NUCA caches due to the conflict hit problem. Our results show that Re-NUCA outperforms D-NUCA of more then 5% on average, but for those applications that strongly suffer from the conflict hit problem we observe performance improvements up to 15%
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