4 resultados para Automorphisms on Affine Varieties
em Aston University Research Archive
Resumo:
Our PhD study focuses on the role of aspectual marking in expressing simultaneity of events in Tunisian Arabic as a first language, French as a first language, as well as in French as a second language by Tunisian learners at different acquisitional stages. We examine how the explicit markers of on-goingness qa:’id and «en train de» in Tunisian Arabic and in French respectively are used to express this temporal relation, in competition with the simple forms, the prefixed verb form in Tunisian Arabic and the présent de l’indicatif in French. We use a complex verbal task of retelling simultaneous events sharing an interval on the time axis based on eight videos presenting two situations happening in parallel. Two types of simultaneity are exploited: perfect simultaneity (when the two situations are parallel to each other) and inclusion (one situation is framed by the second one). Our informants in French and in Tunisian Arabic have two profiles, highly educated and low educated speakers. We show that the participants’ response to the retelling task varies according to their profiles, and so does their use of the on-goingness devices in the expression of simultaneity. The differences observed between the two profile groups are explained by the degree to which the speakers have developed a habit of responding to tasks. This is a skill typically acquired during schooling. We notice overall that the use of qa:’id as well as of «en train de» is less frequent in the data than the use of the simple forms. However, qa:’id as well as «en train de» are employed to play discursive roles that go beyond the proposition level. We postulate that despite the shared features between Tunisian Arabic and French regarding marking the concept of on-goingness, namely the presence of explicit lexical, not fully grammaticalised markers competing with other non-marked forms, the way they are used in the discourse of simultaneous events shows clear differences. We explain that «en train de» plays a more contrastive role than qa:’id and its use in discourse obeys a stricter rule. In cases of the inclusion type of simultaneity, it is used to construe the ‘framing’ event that encloses the second event. In construing perfectly simultaneneous events, and when both «en train de» and présent de l’indicatif are used, the proposition with «en train de» generally precedes the proposition with présent de l’indicatif, and not the other way around. qa:id obeys, but to a less strict rule as it can be used interchangeably with the simple form regardless of the order of propositions. The contrastive analysis of French L1 and L2 reveals learners’ deviations from natives’ use of on-goingness devices. They generalise the use of «en train de» and apply different rules to the interaction of the different marked and unmarked forms in discourse. Learners do not master its role in discourse even at advanced stages of acquisition despite its possible emergence around the basic and intermediate varieties. We conclude that the native speakers’ use of «en train de» involves mastering its role at the macro-structure level. This feature, not explicitly available to learners in the input, might persistently present a challenge to L2 acquisition of the periphrasis.
Resumo:
The existence of different varieties of the acquired reading disorder termed "phonological dyslexia" is demonstrated in this thesis. The data are interpreted in terms of an information-processing model of normal reading which postulates autonomous routes for pronouncing lexical and non-lexical items and identifies a number of separable sub-processes within both lexical and non-lexical routes. A case study approach is used and case reports on ten patients who have particular difficulty in processing non-lexical stimuli following cerebral insult are presented, Chapters 1 and 2 describe the theoretical background to the investigation. Cognitive models of reading are examined in Chapter 1 and the theoretical status of the current taxonomy of the acquired dyslexias discussed in relation to the models. In Chapter 2 the symptoms associated with phonological dyslexia are discussed both in terms of the theoretical models and in terms of the cosistency with which they are reported to occur in clinical studies. Published cases of phonological dyslexia are reviewed. Chapter 3 describes the tests administered and the analysis of error responses. The majority of tests require reading aloud of single lexical or non-lexical items and investigate the effect of different variables on reading performance. Chapter 4 contains the case reports. The final chapter summarises the different patterns of reading behaviour observed. The theoretical model predicts the selective impairment of subsystems within the phonological route. The data provide evidence of such selective impairment. It is concluded that there are different varieties of phonological dyslexia corresponding to the different loci of impairment within the phonological route. It is also concluded that the data support the hypothesis that there are two lexical routes. A further subdivision of phonological dyslexia is made on the basis of selective impairment of the direct or lexical-semantic routes.
Resumo:
Control design for stochastic uncertain nonlinear systems is traditionally based on minimizing the expected value of a suitably chosen loss function. Moreover, most control methods usually assume the certainty equivalence principle to simplify the problem and make it computationally tractable. We offer an improved probabilistic framework which is not constrained by these previous assumptions, and provides a more natural framework for incorporating and dealing with uncertainty. The focus of this paper is on developing this framework to obtain an optimal control law strategy using a fully probabilistic approach for information extraction from process data, which does not require detailed knowledge of system dynamics. Moreover, the proposed control method framework allows handling the problem of input-dependent noise. A basic paradigm is proposed and the resulting algorithm is discussed. The proposed probabilistic control method is for the general nonlinear class of discrete-time systems. It is demonstrated theoretically on the affine class. A nonlinear simulation example is also provided to validate theoretical development.
Resumo:
In this paper we analyse rigidities in the behaviour of the mark-up on regular, midgrade and premium varieties of petrol in the New York area using a set of weekly frequency data and a methodology that analyses the pricing process using deterministic and stochastic techniques. The results are consistent across methodologies and indicate that the speeds of adjustment to the long-run equilibrium mark-up differ across varieties of petrol with margins of the premium variety falling faster than they rise, contrary to the popular claim of welfare-decreasing asymmetries in price transmission. © 2012 The Authors. The Manchester School © 2012 Blackwell Publishing Ltd and The University of Manchester.