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Mazzanti A.,University of Modena and Reggio Emilia | Monaco E.,University of Modena and Reggio Emilia | Monaco E.,Istituto Universitario Of Studi Superiori | Pozzoni M.,STMicroelectronics | Svelto F.,University of Pavia
Digest of Technical Papers - IEEE International Solid-State Circuits Conference

Ultra-scaled CMOS devices offer the possibility of operation beyond 100GHz where new applications are envisioned in the near future, including imaging and spectroscopy systems for scientific, medical, space, and industrial applications at low cost, light weight and easy assembly [1]. However, a long path toward complete systems of any commercial interest is required, even though simple building blocks have already been presented [2-6]. One of the challenges of such high-frequency transceivers is the on-chip reference generation. Adoption of a voltage-controlled oscillator (VCO) at fundamental frequency sets an increasingly severe trade-off between high spectral purity and frequency tuning due to a dramatic reduction of resonator quality factor and large parasitics introduced by active devices and buffers, operating close to the transition frequency. As an example, state-of-the-art varactor-tuned VCOs beyond 100GHz in standard CMOS technology display a tuning range of less than 3%, not enough to cover process spreads [3-5]. An alternative solution relies on frequency multiplication of a lower frequency reference, with the potential advantage of a higher tuning range and lower phase noise set by the lower frequency VCO enslaving the multiplier. ©2010 IEEE. Source

Segagni D.,IRCCS Fondazione Salvatore Maugeri | Tibollo V.,IRCCS Fondazione Salvatore Maugeri | Dagliati A.,Istituto Universitario Of Studi Superiori | Zambelli A.,IRCCS Fondazione Salvatore Maugeri | And 2 more authors.
BMC Bioinformatics

Background: The ONCO-i2b2 platform is a bioinformatics tool designed to integrate clinical and research data and support translational research in oncology. It is implemented by the University of Pavia and the IRCCS Fondazione Maugeri hospital (FSM), and grounded on the software developed by the Informatics for Integrating Biology and the Bedside (i2b2) research center. I2b2 has delivered an open source suite based on a data warehouse, which is efficiently interrogated to find sets of interesting patients through a query tool interface.Methods: Onco-i2b2 integrates data coming from multiple sources and allows the users to jointly query them. I2b2 data are then stored in a data warehouse, where facts are hierarchically structured as ontologies. Onco-i2b2 gathers data from the FSM pathology unit (PU) database and from the hospital biobank and merges them with the clinical information from the hospital information system.Our main effort was to provide a robust integrated research environment, giving a particular emphasis to the integration process and facing different challenges, consecutively listed: biospecimen samples privacy and anonymization; synchronization of the biobank database with the i2b2 data warehouse through a series of Extract, Transform, Load (ETL) operations; development and integration of a Natural Language Processing (NLP) module, to retrieve coded information, such as SNOMED terms and malignant tumors (TNM) classifications, and clinical tests results from unstructured medical records. Furthermore, we have developed an internal SNOMED ontology rested on the NCBO BioPortal web services.Results: Onco-i2b2 manages data of more than 6,500 patients with breast cancer diagnosis collected between 2001 and 2011 (over 390 of them have at least one biological sample in the cancer biobank), more than 47,000 visits and 96,000 observations over 960 medical concepts.Conclusions: Onco-i2b2 is a concrete example of how integrated Information and Communication Technology architecture can be implemented to support translational research. The next steps of our project will involve the extension of its capabilities by implementing new plug-in devoted to bioinformatics data analysis as well as a temporal query module. © 2012 Segagni et al.; licensee BioMed Central Ltd. Source

Brezzi F.,Istituto Universitario Of Studi Superiori | Brezzi F.,King Abdulaziz University | Brezzi F.,CNR Institute for Applied Mathematics and Information Technologies | Marini L.D.,University of Pavia
Computer Methods in Applied Mechanics and Engineering

We discuss the application of Virtual Elements to linear plate bending problems, in the Kirchhoff-Love formulation. As we shall see, in the Virtual Element environment the treatment of the C1-continuity condition is much easier than for traditional Finite Elements. The main difference consists in the fact that traditional Finite Elements, for every element K and for every given set of degrees of freedom, require the use of a space of polynomials (or piecewise polynomials for composite elements) for which the given set of degrees of freedom is unisolvent. For Virtual Elements instead we only need unisolvence for a space of smooth functions that contains a subset made of polynomials (whose degree determines the accuracy). As we shall see the non-polynomial part of our local spaces does not need to be known in detail, and therefore the construction of the local stiffness matrix is simple, and can be done for much more general geometries. © 2012 Elsevier B.V. Source

Brezzi F.,Istituto Universitario Of Studi Superiori | Brezzi F.,CNR Institute for Applied Mathematics and Information Technologies | Evans J.A.,University of Texas at Austin | Hughes T.J.R.,University of Texas at Austin | And 2 more authors.
Computer Methods in Applied Mechanics and Engineering

We introduce a new framework for the development of thin plate finite elements, the " twist-Kirchhoff theory" A family of rectangular plate elements is derived that takes advantage of the special structure of this new theory. Particular attention is focused on the lowest-order member of the family, an eight degree-of-freedom, four-node element with mid-side rotations whose stiffness matrix is exactly computed with one-point Gaussian quadrature. We prove a convergence theorem for it and various error estimates. These are also generalized to the higher-order elements in the family. Numerical tests corroborate the theoretical results. © 2011 Elsevier B.V. Source

Troja E.,NASA | Troja E.,University of Maryland University College | Read A.M.,University of Leicester | Tiengo A.,Istituto Universitario Of Studi Superiori | And 2 more authors.
Astrophysical Journal Letters

The detection of the first gravitational wave (GW) transient GW150914 prompted an extensive campaign of follow-up observations at all wavelengths. Although no dedicated XMM-Newton observations have been performed, the satellite passed through the GW150914 error region during normal operations. Here we report the analysis of the data taken during these satellite slews performed two hours and two weeks after the GW event. Our data cover 1.1 and 4.8 deg2 of the final GW localization region. No X-ray counterpart to GW150914 is found down to a sensitivity of 6 '10-13 erg cm-2 s-1 in the 0.2-2 keV band. Nevertheless, these observations show the great potential of XMM-Newton slew observations for searching for the electromagnetic counterparts of GW events. A series of adjacent slews performed in response to a GW trigger would take ≲1.5 days to cover most of the typical GW credible region. We discuss this scenario and its prospects for detecting the X-ray counterpart of future GW detections. © 2016. The American Astronomical Society. All rights reserved.. Source

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