Search results for "Machines"

showing 10 items of 113 documents

Non-Linear Hysteretic Instability in Rotating Machinery

2013

The destabilizing influence of the shaft hysteresis on the supercritical whirl of rotating machines can be efficiently counterbalanced by proper external dissipative sources in the supports and/or anisotropic suspension systems. The hysteretic effect may be treated either by dry or viscous models obtaining different but somehow similar results in the hypothesis of small dissipation levels. Thus the linear viscous assumption is often accepted as a crude approximation for a straightforward analysis of the whirling instability. Nevertheless the internal friction should be regarded most likely as non-linear and could be approximated for example by Coulombian models taking thus into account also the releasing effect of some shrink-fit coupling present in the mechanical assembly.
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Advanced Monitoring of Rotor Broken Bar in Double Squirrel Cage Induction Machines Based on Wavelet Analysis

2012

The diagnosis of induction machine faults is commonly realized through Motor Current Signature Analysis (MCSA), i.e. by classical spectrum analysis of the input currents. In case of large or double cage induction motors, rotor broken bars fault detection based on sideband current components may fail due to the presence of inter bar currents that reduce the degree of rotor asymmetry, leading to reduced relevance of these spectral components. But inter bar currents produce core vibrations in the axial direction, which can be detected using vibration analysis techniques, in order to overcome the limits of the classical MCSA for these purposes. In this paper, an advanced use of the Discrete wav…

Transverse flux permanent magnet machines claw pole topology soft magnetic composite finite element analysis cost-effectiveness assemblyTransverse flux permanent magnet machines claw pole topology soft magnetic composite finite element analysis cost-effectiveness assembly.Settore ING-IND/32 - Convertitori Macchine E Azionamenti Elettrici
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Design of a transverse flux machine for power generation from seawaves

2014

In this paper, we present a transverse flux linear generator. We investigate the possibility to use this generator to extract energy from seawaves. We propose an optimization procedure that allows us to obtain an optimized design of the generator. The optimized design of the converter shows a power generation capability index much higher than other renewable systems.

Transverse fluxPhysicsPhysical propertieGenerator (computer programming)business.industryElectrical engineeringGeneral Physics and AstronomyElectric generatorOptimized designRenewable energylaw.inventionPhysics Capability indicePhysical properties; Physics Capability indices; Linear generators; Optimization procedures; Optimized designs; Transverse flux; Transverse flux machinesLinear generatorTransverse fluxElectricity generationlawLinear congruential generatorOptimization procedureProcess capability indexTransverse flux machinesbusinessEnergy (signal processing)
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On computation in the limit by non-deterministic Turing machines

1974

Turing machinenon-deterministic:MATHEMATICS [Research Subject Categories]computation in the limitTuring machineslimit computations
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Distributed ASM - Pitfalls and solutions

2014

Published version of a chapter in the book: Abstract State Machines, Alloy, B, TLA, VDM, and Z. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-662-43652-3_18 While sequential Abstract State Machines (ASM) capture the essence of sequential computation, it is not clear that this is true of distributed ASM. This paper looks at two kinds of distributed process, one based on a global state and one based on variable access. Their commonalities are extracted and conclusions for the general understanding of distributed computation are drawn, providing integration between global state and variable access.

Variable (computer science)Theoretical computer scienceProcess (engineering)Sequential consistencyComputer scienceComputationAbstract state machinesSequential computationVDP::Technology: 500::Information and communication technology: 550State (computer science)Context switch
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Monitoring and Diagnosis of Failures in Squirrel-Cage Induction Motors Due to Cracked or Broken Bars

2011

In this paper three diagnostic procedures, based on on the vibration, current and instantaneous power monitoring for the detection and monitoring of incipient faults as cracks or bar breaks on squirrel cage motors are briefly reminded. The experimental investigations, carried out at the SDESLab (Sustainable Development Energy Savings Laboratory) of the University of Palermo in order to underline merits and drawbacks of the methods applied to the same die cast squirrel cage induction motor, are presented. The results of the investigations confirmed the effectiveness of the diagnostic procedures here considered.

VibrationEngineeringbusiness.industrySquirrel-cage rotorStructural engineeringInduction machines squirrel cage fault diagnosis broken rotor bar.Settore ING-IND/32 - Convertitori Macchine E Azionamenti ElettricibusinessInduction motor
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On the discrete linear ill‐posed problems

1999

An inverse problem of photo‐acoustic spectroscopy of semiconductors is investigated. The main problem is formulated as the integral equation of the first kind. Two different regularization methods are applied, the algorithms for defining regularization parameters are given. Diskrečiųjų blogai sąlygotų uždavinių klausimu Santrauka Darbe nagrinejamas foto‐akustines spektroskopijos puslaidininkiuose uždavinys, kuriame i vertinami nešeju difuzijos ir rekombinacijos procesai. Reikia atstatyti šaltinio funkcija f(x), jei žinoma antrosios eiles difuzijos lygtis ir atitinkamos kraštines salygos. Naudojantis matavimu, atliktu ivairiuose dažniuose, rezultatais sprendžiamas atvirkštinis uždavinys, kel…

Well-posed problemMathematical analysisRegularization perspectives on support vector machinesBackus–Gilbert method-Inverse problemIntegral equationRegularization (mathematics)Tikhonov regularizationModeling and SimulationInverse scattering problemQA1-939Applied mathematicsMathematicsAnalysisMathematicsMathematical Modelling and Analysis
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A Micro Wind Generation System for Local DoS Applications

2010

In this paper a wind electrical power generation system for Distributed on Site (DoS) applications is proposed. This system was developed and conceived in order to guarantee simple installation, use and service, obtaining a product that can be easily industrialized and put into the market with limited costs. The field of application of such an electrical generation system is addressed towards domestic or at the most toward condominium applications concerning moreover the opportunity of working in addition to combined photovoltaic and solar-thermal systems to enhance the renewable energy generation at house level (DoS). The proposed system has its hot spot in the blades shape, in the wind fl…

Wind generation wind turbines permanent magnet machines finite element analysisSettore ING-IND/32 - Convertitori Macchine E Azionamenti Elettrici
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Machines et socialismes à l'ère industrielle

2016

International audience

[ SHS ] Humanities and Social Sciencessocialismes[SHS] Humanities and Social Sciencesère industriellemachinesComputingMilieux_MISCELLANEOUS[SHS]Humanities and Social Sciences
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Dire le refus des machines : pétitions ouvrières et représentations de l'ordre économique en France en 1848

2009

Quand eclate la Revolution de 1848, le machinisme, identifie a la grande industrie britannique et a son pauperisme, suscite toujours de nombreuses inquietudes. Face a l’impossibilite croissante de dire le refus des machines, les travailleurs et leurs porte-parole imaginent des strategies alternatives pour en attenuer et en reguler les effets...

[SHS.DROIT] Humanities and Social Sciences/Law05 social sciencespétitions ouvrièresordre économique06 humanities and the artsGeneral Medicine050905 science studies0603 philosophy ethics and religion[ SHS.DROIT ] Humanities and Social Sciences/Law[SHS.DROIT]Humanities and Social Sciences/Law060302 philosophy0509 other social sciencesmachines1848ComputingMilieux_MISCELLANEOUS
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