838 research outputs found

    WARP: Weight Associative Rule Processor. A dedicated VLSI fuzzy logic megacell

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    During the last five years Fuzzy Logic has gained enormous popularity in the academic and industrial worlds. The success of this new methodology has led the microelectronics industry to create a new class of machines, called Fuzzy Machines, to overcome the limitations of traditional computing systems when utilized as Fuzzy Systems. This paper gives an overview of the methods by which Fuzzy Logic data structures are represented in the machines (each with its own advantages and inefficiencies). Next, the paper introduces WARP (Weight Associative Rule Processor) which is a dedicated VLSI megacell allowing the realization of a fuzzy controller suitable for a wide range of applications. WARP represents an innovative approach to VLSI Fuzzy controllers by utilizing different types of data structures for characterizing the membership functions during the various stages of the Fuzzy processing. WARP dedicated architecture has been designed in order to achieve high performance by exploiting the computational advantages offered by the different data representations

    Recurrent Neural Networks Applied to GNSS Time Series for Denoising and Prediction

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    Global Navigation Satellite Systems (GNSS) are systems that continuously acquire data and provide position time series. Many monitoring applications are based on GNSS data and their efficiency depends on the capability in the time series analysis to characterize the signal content and/or to predict incoming coordinates. In this work we propose a suitable Network Architecture, based on Long Short Term Memory Recurrent Neural Networks, to solve two main tasks in GNSS time series analysis: denoising and prediction. We carry out an analysis on a synthetic time series, then we inspect two real different case studies and evaluate the results. We develop a non-deep network that removes almost the 50% of scattering from real GNSS time series and achieves a coordinate prediction with 1.1 millimeters of Mean Squared Error

    The structure of a minimal nn-chart with two crossings II: Neighbourhoods of Γ1Γn1\Gamma_1\cup\Gamma_{n-1}

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    Given a 2-crossing minimal chart Γ\Gamma, a minimal chart with two crossings, set α=min{ i  \alpha=\min\{~i~|~there exists an edge of label ii containing a white vertex}\}, and β=max{ i  \beta=\max\{~i~|~there exists an edge of label ii containing a white vertex}\}. In this paper we study the structure of a neighbourhood of ΓαΓβ\Gamma_\alpha\cup\Gamma_\beta, and propose a normal form for 2-crossing minimal nn-charts, here Γα\Gamma_\alpha and Γβ\Gamma_\beta mean the union of all the edges of label α\alpha and β\beta respectively.Comment: 57 pages, 36 figure

    Tourism trends in the world's main destinations before and after the 2008 financial crisis using UNWTO official data

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    The first decade of the present century has been characterized by several economic shocks such as the 2008 financial crisis. In this data article we present the annual percentage growth rates of the main tourism indicators in the world׳s top tourist destinations: the United States, China, France, Spain, Italy, United Kingdom, Germany, Turkey, Mexico and Austria. We use data from the Compendium of Tourism Statistics provided by the World Tourism Organization (http://www2.unwto.org/content/data-0). It has been demonstrated that the dynamics of growth in the tourism industry pose different challenges to each destination in the previous study "Positioning and clustering of the world׳s top tourist destinations by means of dimensionality reduction techniques for categorical data" (Claveria and Poluzzi, 2016, [1]). We provide a descriptive analysis of the variables over the period comprised between 2000 and 2010. We complement the analysis by graphing the evolution of the main variables so as to visually represent the co-movements between tourism variables and economic growth

    Foundation Soil Influence on the Seismic Response of Piers

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    Significant experimental dynamic tests by vibrodyne were conducted on single piers of a motorway near Livomo (Italy). Tests were conducted on structures similar to each other but founded on two different type of soils (under consolidated silts below the water table and over consolidated clays) and very different dynamic responses were found in terms of damping and natural frequencies. This effect was particularly evident for single piles proving the importance of soil characteristics upon the dynamic response of the structure. It is refere also a numerical investigation about the behavior of identical structures founded on different soils and subjected to the same seismic input

    Positioning and clustering of the world's top tourist destinations by means of dimensionality reduction techniques for categorical data

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    This study aims to cluster the world's top tourist destinations based on the growth of the main tourism indicators over the period between 2000 and 2010. It ranks the destinations with respect to the average growth rate over the sample period. The results find that both China and Turkey are at the top of the rankings of all variables. By assigning a numerical value to each country corresponding to its position, a Spearman's coefficient is calculated and a negative correlation found between a destination's dependency on tourism and the profitability of the tourism activity. Finally, several multivariate techniques for dimensionality reduction are used to cluster all destinations according to their positioning. Three groups are obtained: China, Turkey, and the rest of the destinations. These results show that the persistent growth of the tourism industry poses different challenges in different markets regarding destination marketing and management

    Assessing the Association of Pioglitazone Use and Bladder Cancer Through Drug Adverse Event Reporting

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    OBJECTIVE\u2014To analyze the association between pioglitazone use and bladder cancer through a spontaneous adverse event reporting system for medications. RESEARCH DESIGN AND METHODS\u2014Case/noncase bladder cancer reports associated with antidiabetic drug use were retrieved from the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (AERS) between 2004 and 2009 and analyzed by the reporting odds ratio (ROR). RESULTS\u2014Ninety-three reports of bladder cancer were retrieved, corresponding to 138 drug reaction pairs (pioglitazone, 31; insulin, 29; metformin, 25; glimepiride, 13; exenatide, 8; others, 22). RORwas indicative of a definite risk for pioglitazone (4.30 [95%CI 2.82\u20136.52]), and a much weaker risk for gliclazide and acarbose, with very few cases being treated with these two drugs (6 and 4, respectively). CONCLUSIONS\u2014In agreement with preclinical and clinical studies, AERS analysis is consistent with an association between pioglitazone and bladder cancer. This issue needs constant epidemiologic surveillance and urgent definition by more specific studies

    Dapagliflozin and cardiovascular outcomes: anything else to DECLARE?

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    Introduction: Individuals with type 2 diabetes mellitus (T2DM) have increased cardiovascular risk with regulatory agencies requiring cardiovascular outcome trials (CVOTs) for the approval of new antidiabetic drugs. Areas covered: In this paper, the authors critically discuss the background, trial design, results and implications of a recent CVOT [NCT01730534; DECLARE-TIMI 58 study], which demonstrated that dapagliflozin was non-inferior to placebo in terms of major adverse cardiovascular events, and superior for the occurrence of hospitalization for heart failure (HF) and composite renal endpoints, thus confirming the cardiovascular benefit of sodium-glucose co-transporter-2 (SGLT2) inhibitors. No statistically-significant effects were found for amputations, fractures, and stroke (debated safety issues having emerged in previous CVOTs). Expert opinion: DECLARE-TIMI 58 is the longest (4.2 years of follow up), largest (>17,000 participants) and most inclusive (only 41% of individuals with established atherosclerotic cardiovascular disease) CVOT raising the debate towards SGLT2 inhibitor therapy in primary prevention and the potential use of these drugs also in patients with HF without T2DM and other subpopulations
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