The effect of actuator and sensor placement on the active control of rotor unbalance

This paper investigates both theoretically and experimentally the effect of the location and number of sensors and magnetic bearing actuators on both global and local vibration reduction along a rotor using a feedforward control scheme. Theoretical approaches developed for the active control of beams have been shown to be useful as simplified models for the rotor scenario. This paper also introduces the time-domain LMS feedforward control strategy, used widely in the active control of sound and vibration, as an alternative control methodology to the frequency-domain feedforward approaches commonly presented in the literature. Results are presented showing that for any case where the same number of actuators and error sensors are used there can be frequencies at which large increases in vibration away from the error sensors can occur. It is also shown that using a larger number of error sensors than actuators results in better global reduction of vibration but decreased local reduction. Overall, the study demonstrated that an analysis of actuator and sensor locations when feedforward control schemes are used is necessary to ensure that harmful increased vibrations do not occur at frequencies away from rotor-bearing natural frequencies or at points along the rotor not monitored by error sensors.

Gender, the environment and the sustainability of development

Includes bibliography

Policies and practices for the use of information and communications technologies (ICTs) in education in Latin America and the Caribbean

Includes bibliography

Industrial policy and development

Includes bibliography

Funções textual-interativas dos marcadores discursivos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Affordances: a relação entre agente e ambiente

Pós-graduação em Filosofia - FFC

Estudo teórico - experimental do titanato de cálcio - 'CA''TI''OIND.3'

Pós-graduação em Química - IQ

As concepções de família presentes nos planos diretores das instituições de Educação Infantil: avanços, contradições e possibilidades

Pós-graduação em Educação - FCT

A construção e utilização de um Objeto de Aprendizagem através da perspectiva lógico-histórica na formação do conceito números inteiros

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Violência e indisciplina em meio escolar: aspectos teóricometodológicos da produção acadêmica no período de 2000 a 2005

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O fundo de arquivo e o princípio de proveniência: uma observação entre a teoria e a prática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A metáfora e a sua representação em sistemas de processamento automático de línguas naturais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ut pictura poesis: a poesia vulgar pintada por Antônio da Fonseca Soares

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A periodization of Latin American development in the Robinsonian tradition

This paper analyzes Joan Robinson's growth model and then adapts it in order to provide an explanatory taxonomy of Growth Eras. The Growth Eras or Ages were for Robinson a way to provide logical connections between output growth, capital accumulation, the degree of thriftiness, the real wage and illustrate a catalogue of growth possibilities. This modified taxonomy follows the spirit of Robinson's work, but it takes different theoretical approaches. which imply that some of the classifications do not fit perfectly the ones here suggested. Latin America has moved from a Golden Age in the 1950s and 1960s to a Leaden Age in the 1980s, having two traverse periods, one of which the process of growth and industrialization accelerated in the late 1960s and early 1970s, which is referred to as a Galloping Platinum Age, an one in which a process of deindustrialization and reprimarization and maquilization of the productive structure took place, starting in the 1990s, which could be referred as the Creeping Platinum Age.

Public debt sustainability in the Caribbean

This paper analyses public debt in the most indebted Caribbean countries – i.e. Barbados, Belize, Guyana, Jamaica, Antigua and Barbuda, Dominica, Grenada, and St. Kitts and Nevis – from the standpoint of its sustainability. A level of debt is deemed to be sustainable when the debt-to-GDP ratio remains constant or declines. The concept of sustainability is closely linked to that of solvency. A government is solvent if the net present value of its future primary balances (i.e. that excludes interest payments) is equal to or greater than the present value of public debt stock. It can be demonstrated that if the debt-to-GDP ratio is not on an explosive path, that it either stable or decreasing, the solvency condition holds. It is worth noting that the concept of fiscal sustainability addressed in this paper differs from that of optimality of public debt. The analysis that follows is intended to determine whether the service of the current debt levels is consistent with the fiscal stance. Therefore, it does not set out to identify the target debt level based on any optimality criteria. The next section presents the main features of different theoretical approaches to analyse public debt sustainability.1 Section II discusses the situation of public debt in the Caribbean countries showing different indicators; Section III analyses debt sustainability in countries with access to market financing; Section IV does the same in Guyana – a country dependent on concessional financing and, as such, included in the Highly Indebted Poor Countries (HIPC) Initiative – and the countries of the Eastern Caribbean Currency Union (ECCU). Sections V and VI go beyond debt levels as determinants of fiscal sustainability, highlighting the importance of the currency composition of debt and the variability of fiscal revenue. The last section concludes.