63,300 research outputs found
A study of fault diagnosis and recovery techniques for manufacturing systems
No full textThis chapter describes a framework for the development of a diagnosis methodology for industrial manufacturing systems. The aim of the project is to support technicians that supervise the manufacturing plant to identify the causes of faults and failures on the machine and, in particular, to indicate a procedure for the recovery of its working condition. The chapter presents a study as the first step of a design project whose objective is to realize a supervisory system with advanced features devoted to Faults Detection and Isolation (FDI) for the manufacturing industry, with an emphasis on its integration with Human-Machine Interfaces. The requirements described in the chapter are defined giving particular care to the peculiarities of the application domain to allow the design of a powerful, but easy to use for industrial technicians, diagnostic system. An example of a manufacturing machine quite common in the packaging industry is schematized in the chapter, which is analyzed to define the fault trees for the most critical failure modes. © 2007 Copyright © 2007 Elsevier Ltd All rights reserved
Flavor asymmetry of the polarized light sea: models vs. data
No full textAbstractThe flavor asymmetry of the polarized light sea, Δū−Δd̄, discriminates between different model calculations of helicity densities. We show that the chiral chromodielectric model, differently from models based on a 1/Nc expansion, predicts a small value for this asymmetry, what seems in agreement with preliminary HERMES data
Fuzzy Control Techniques Applied to Wind Turbine Systems and Hydroelectric Plants
No full textThe interest on the use of renewable energy resources is increasing, especially wind and hydro powers. To this aim, fuzzy control techniques represent viable strategies that can be employed for this purpose, thanks to the features of these nonlinear dynamic processes working over a wide range of operating conditions, driven by stochastic inputs, excitations and disturbances. Based on past investigations carried out by the authors about the control of wind turbines and hydroelectric power plants, this paper provides some guidelines on the design and application of the control strategies suitable to these energy conversion systems. The working conditions of these energy conversion systems are also taken into account to highlight the reliability and robustness characteristics of the developed control strategies
Hardware–In–The–Loop Assessment of Robust Fuzzy Control Solutions for Hydroelectric and Wind Turbine Models
No full textThe interest towards renewable energy resources is increasing, and in particular it concerns wind and hydro powers, where the key point regards their efficient conversion into electric energy. To this end, control techniques can be used to meet this purpose, especially the ones relying on fuzzy models, due to their capabilities to manage nonlinear dynamic processes working in different conditions, and affected by faults, measurement errors, uncertainty and disturbances. The design methods addressed in this paper were already developed and validated for wind turbine plants, and important results can be achieved from their appropriate design and application to hydroelectric plants. This is the key issue of the paper, which recalls some considerations on the proposed solutions, as well as their validation to these energy conversion systems. Note that works available in the related literature that consider both wind and hydraulic energy conversion systems investigate a limited number of common issues, thus leading to little exchange opportunities and reduced common research aspects. Another important point addressed in the paper is that the proposed control design solutions are able to take into account the different working conditions of these power plants. Moreover, faults, uncertainty, disturbance and model reality mismatch effects are also considered when analyzing the reliability and robustness features of the derived control schemes. To this end, proper hardware in the loop tools are considered to verify and validate the developed control schemes in more realistic environments. Copyright (C) 2022 The Authors
Control Strategy Applied to Smart Photovoltaic Inverters for Reactive Power Exchange Through Volt-Var Control to Improve Voltage Quality in Electrical Distribution Networks
No full textPhotovoltaic (PV) generation systems have become part of the electrical distribution networks due to their clean energy and adaptability. The increasing energy consumption and the several load types in the distribution network could produce voltage deviation. Therefore, there are some strategies, which are used to solve this problem, for example, capacitor banks, voltage regulators, transformer tap variation, static Var compensators, and reactive power exchange employing inverters. This article presents a smart inverter able to deliver and absorb reactive power through Volt-Var control to solve voltage deviations. The inverter compensates for voltage deviation in the primary transformer, whether inductive or capacitive loads are connected in the point of common coupling (PCC). In consequence, the inverter improves the voltage quality in the entire network. Finally, total harmonics percentage (THD) and frequency deviation have an acceptable performance during the operation, due to the inverter hardware configuration, and the phase-locked loop (PLL) implementation
Fault {D}etection, Identification and Reconfiguration Techniques: FDI and reconfiguration methods and the problem of their integration towards full RFTFC
No full textA research initiative within the framework of the Group for Aeronautical Research and
Technology in Europe (GARTEUR) co-operation program examined the application of
multiple fault-tolerant flight control (FTFC) algorithms in a realistic aircraft accident
scenario. An aircraft model, reconstructed using the Digital Flight Data Recorder (DFDR) of
the 1992 Amsterdam Bijlmermeer aircraft accident (Flight 1862), was used to evaluate the
algorithms in an offline benchmark and an online piloted evaluation. This paper focuses on
the experiment development for a piloted simulator evaluation of innovative reconfigurable
control algorithms applied to a damaged civil transport aircraft. The evaluation scenario,
measurements and experimental design, as well as the real-time implementation are
described. The evaluation showed that the FTFC algorithms were able to restore
conventional control strategies after the aircraft configuration has changed dramatically due
to severe failures. The algorithms supported the pilot after a failure by lowering workload
and allowing a safe return to the airport. For some failures, the handling qualities were
shown to degrade less with a failure than the baseline classical control system
Erratum to: Effect of moderate red wine intake on cardiac prognosis after recent acute myocardial infarction of subjects with Type 2 diabetes mellitus (Diabetic Medicine, (2006), 23, 9, (974-981), 10.1111/j.1464-5491.2006.01886.x)
No full textIn an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola.In an article by Marfella et al, the author name C. Saron is incorrect and should be listed as C. Sardu. Therefore the correct author list is: R. Marfella, F. Cacciapuoti, M. Siniscalchi, F. C. Sasso, F. Marchese, F. Cinone, E. Musacchio, M. A. Marfella, L. Ruggiero, G. Chiorazzo, D. Liberti, G. Chiorazzo, G. F. Nicoletti, C. Sardu, F. D'Andrea, C. Ammendola, M. Verza and L. Coppola
Measurement of the ratio of prompt χ c to J / ψ production in pp collisions at √s = 7 TeV
No full textThe prompt production of charmonium χ c and J / ψ states is studied in proton-proton collisions at a centre-of-mass energy of √s = 7 TeV at the Large Hadron Collider. The χ c and J / ψ mesons are identified through their decays χ c → J / ψ γ and J / ψ → μ + μ - using 36 pb - 1 of data collected by the LHCb detector in 2010. The ratio of the prompt production cross-sections for χ c and J / ψ, σ (χ c → J / ψ γ) / σ (J / ψ), is determined as a function of the J / ψ transverse momentum in the range 2 < p T J / ψ < 15 GeV / c. The results are in excellent agreement with next-to-leading order non-relativistic expectations and show a significant discrepancy compared with the colour singlet model prediction at leading order, especially in the low p T J / ψ region
Faust : Romance Of The Secret Tribunals / By George W. M. Reynolds, Author Of "The Mysteries Of London", "Pickwick Abroad", &c. Illustrated In The First Style Of The Art
No full textFAUST : ROMANCE OF THE SECRET TRIBUNALS / BY GEORGE W. M. REYNOLDS, AUTHOR OF "THE MYSTERIES OF LONDON", "PICKWICK ABROAD", &C. ILLUSTRATED IN THE FIRST STYLE OF THE ART
Faust : Romance Of The Secret Tribunals / By George W. M. Reynolds, Author Of "The Mysteries Of London", "Pickwick Abroad", &c. Illustrated In The First Style Of The Art (1)
Cover (1)
Umschlagtitel (8)
Titelseite (9)
Contents (10)
Illustrations / Prologue (11)
Prologue (12)
Chapter I.-XCV. (14)
Epilogue (119
Erratum to: Effects of nutraceuticals on quality of life and sexual function of perimenopausal women (Journal of Endocrinological Investigation, (2017), 40, 1, (27-32), 10.1007/s40618-016-0500-2)
No full textUnfortunately, one of the co-author first name was wrongly published in the original version. The complete correct name of the co-author is given below. A. M. C. Rapisarda. The original version of this article is also updated
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