97 research outputs found
O âDarwinismo Socialâ Perante a QuestĂŁo da AssistĂȘncia
Tendo como referĂȘncia o quadro de misĂ©ria/ pauperismo do sĂ©culo XIX, o propĂłsito crĂtico deste ensaio Ă© a influĂȘncia da teoria darwinista na questĂŁo social. ApĂłs um breve enquadramento dessas reflexĂ”es, no quadro da problemĂĄtica da pobreza, a ĂȘnfase Ă© colocada no pensamento de Herbert Spencer que advogava os aspectos positivos da pobreza enquanto instrumento de selecção dos menos capazes. O que estĂĄ em causa, para o autor deste artigo, Ă© demonstrar como esses mesmos argumentos spencerianos emergiram em defesa de um posicionamento crĂtico no quadro de qualquer tipo de intervenção assistencial. / In the context of the 19th century framework of misery/pauperism, the critical purpose of this article is the influence of the Darwinian theory on the social question. After a brief framing of those reflections, the emphasis is placed on the thought of Herbert Spencer about what he considered the positive aspects of poverty as a selection instrument of the less capable. What is at question, for the author of this article, is to demonstrate how the Spencerian thought on poverty defend, in fact, a critical position in the field of any kind of assistance intervention
Stationary Random Fields on the Unitary Dual of a Compact Group
We generalise the notion of wide-sense stationarity from sequences of complex-valued random variables indexed by the integers, to fields of random variables that are labelled by elements of the unitary dual of a compact group. The covariance is positive definite, and so it is the Fourier transform of a finite central measure (the spectral measure of the field) on the group. Analogues of the Cramer and Kolmogorov theorems are extended to this framework. White noise makes sense in this context and so, for some classes of group, we can construct time series and investigate their stationarity. Finally we indicate how these ideas fit into the general theory of stationary random fields on hypergroups
AR and MA representation of partial autocorrelation functions, with applications
We prove a representation of the partial autocorrelation function (PACF), or
the Verblunsky coefficients, of a stationary process in terms of the AR and MA
coefficients. We apply it to show the asymptotic behaviour of the PACF. We also
propose a new definition of short and long memory in terms of the PACF.Comment: Published in Probability Theory and Related Field
Queues with LĂ©vy input and hysteretic control
We consider a (doubly) reflected Lévy process where the Lévy exponent is controlled by a hysteretic policy consisting of two stages. In each stage there is typically a different service speed, drift parameter, or arrival rate. We determine the steady-state performance, both for systems with finite and infinite capacity. Thereby, we unify and extend many existing results in the literature, focusing on the special cases of M/G/1 queues and Brownian motion. © The Author(s) 2009
Simple consistent estimation of the coefficients of a linear filter
AbstractA simple procedure is proposed for estimating the coefficients {Ï} from observations of the linear process X1=âxJ=0ÏJZ1âj, 1=1,2⊠The method is based on the representation of X1 in terms of the innovations, XnâXn, n=1,âŠ, 1, where Xn is the best mean square predictor of Xn is span {X1,âŠX0â1}. The asymptotic distribution of the sequence of estimators is derived and its applications to inference for ARMA processes are discussed
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