6,963 research outputs found

    Identification of leakages by calibration of WDS models

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    Open Access journalCopyright © 2013 The Authors. Published by Elsevier Ltd.12th International Conference on Computing and Control for the Water Industry, CCWI2013Leakage detection is critical for the proper management of water distribution systems (WDS). This paper proposes a leak detection approach based on a Bayesian calibration method. The methodology uses a newly formulated index, μ, which takes into account the variation of roughness in pipes between the calibrated models with and without leaks. Case studies, which use literature networks, are presented to demonstrate how the approach can be used in identifying pipes with losses. The approach starts with a calibration method followed by the analysis of sensitivity matrices. The approach proved to be effective in finding leaks, but the results depend crucially on the number and quality of the observed data.European CommissionEuropean Social FundRegion of Calabri

    Identification of Measurement Points for Calibration of Water Distribution Network Models

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    AbstractMuch importance is given to determining the input data for water distribution system networks, particularly with regard to urban networks, because the design and the management of WDS are based on a verification model. Good calibration of models is required to obtain realistic results. This is possible by the use of a certain number of measurements: flow in pipes and pressure in nodes. The purpose of this paper is to analyze a new model able to provide guidance on the choice of measurement points to obtain the site data. All analyses are carried out firstly on literature networks and then on a real network using a new approach based on sensitivity matrices

    Model calibration as a tool for leakage identification in WDS: A real case study

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    16th Water Distribution System Analysis Conference, WDSA2014 — Urban Water Hydroinformatics and Strategic PlanningCopyright © 2014 The Authors. Published by Elsevier Ltd.Water leakage detection is important for a proper management of water distribution systems (WDS). This paper proposes the application of the leak detection approach based on a new Bayesian calibration methodology. The methodology uses a new developed index μ, which takes into account the difference in roughness values in pipes of the calibrated models with and without leaks. The case study is referred to a real network and is presented to demonstrate how the approach can be used in identifying pipes with losses. The approach starts with the UNINET calibration method followed by the analysis of sensitivity matrices. The case study proves that the approach is effective in finding leaks in real networks, but the results depend on the quality of the observed data

    Optical bistability in a Λ\Lambda-type atomic system including near dipole-dipole interaction

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    The advantage of optical bistability (OB) using three-level electromagnetically induced transparency (EIT) atomic system over the two-level system is its controllability, as absorption, dispersion, and optical nonlinearity in one of the atomic transitions can be modified considerably by the field interacting with nearby atomic transitions. This is due to induced atomic coherences generated in such EIT system. The inclusion of near dipole-dipole (NDD) interaction among atoms further modifies absorption, dispersion, and optical nonlinearity of three-level EIT system and the OB can also be controlled by this interaction, producing OB to multistability.Comment: 15 pages, 6 figure

    The Combination of Dupilumab with Other Monoclonal Antibodies

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    Introduction: Dupilumab is an interleukin-4 (IL-4) receptor alpha antagonist indicated for the treatment of moderate-to-severe atopic dermatitis (AD), which could be associated with atopic and non-atopic comorbidities for which concomitant administration of targeted pharmacotherapy including monoclonal antibodies could be required. However, the safety of combining dupilumab with other monoclonal antibodies for different therapeutic indication may be debated. Methods: We conducted an extensive search in MEDLINE via PubMed for original articles published from January 1, 2017 to October 22, 2022, reporting clinical cases in whic
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