Les contacts intergroupes, en général, et interculturels, en particulier, s’opèrent rarement sans heurts. Le Modèle d’Acculturation Interactif (Bourhis, Moïse, Perreault & Senecal, 1997) se situe au carrefour de la psychologie de l’acculturation et de la psychologie sociale, en ce sens qu’il intègre pleinement la question des relations intergroupes entre la majorité d’accueil d’un pays d’immigration et les minorités qui s’y installent. C’est pourquoi nous nous sommes basés sur les orientations d’acculturation qu’il décrit pour montrer, au travers de trois études, que certaines d’entre elles prédisposent le groupe majoritaire à exprimer des intentions de comportements discriminants versus non discriminants à l’égard de membres d’un exogroupe culturel, ethnique ou racial. Nous avons qualifié ces intentions de comportements de propension à discriminer du groupe majoritaire. Privilégier l’homogénéité des groupes (assimilation, ségrégation et exclusion) conduit, d’une manière générale, à une plus forte propension à discriminer que le fait d’accepter ou d’approuver des situations d’hétérogénéité culturelle (intégration de transformation, intégration, individualisme). Nous avons néanmoins observé une exception dans le cas de l’orientation intégrationniste, dans la mesure où si les individus qui endossent cette orientation rejettent massivement les comportements discriminants explicitement hostiles, ils tendent à faire preuve de « discrimination bienveillante » (Fehr & Sassenberg, 2009). Les études 2 et 3 se sont déroulées en plusieurs temps, ce qui a permis d’appréhender la progression des attitudes et de la propension à discriminer de professionnels de l’insertion, d’étudiants et de futurs cadres de la fonction publique à l’issue de formations visant à prévenir et lutter contre les discriminations. Ce sont surtout ces intentions de comportements discriminants « bienveillants » qui sont sujettes à évolution. L’ensemble des résultats invite à considérer la mise en place de formations qui travailleraient sur la décatégorisation (Brewer & Miller, 1984) et encourageraient par conséquent à l’individualisme dans certaines circonstances, notamment professionnelles et/ou organisationnelles. Enfin, il conviendrait d’examiner, plus généralement, l’impact des politiques assimilationnistes sur l’efficacité des dispositifs de lutte contre les discriminations mis en œuvre, par ailleurs, au niveau étatique. / Intergroup contacts in general, and intercultural relationships in particular, rarely take place without conflicts. The Interactive Acculturation Model (Bourhis, Moïses, Perreault & Senecal, 1997) is at the crossroads between the psychology of acculturation and social psychology. Indeed, the question of intergroup relations between majority and minority members is completely integrated in the IAM. That is why we focused on acculturation orientations the model describes to show, through three studies, which one predisposes the majority group to express discriminating behaviours versus non discriminating behaviours towards the members of a cultural, ethnic or racial out-group. We called these intentions "propensity to discriminate". People who favour the homogeneity of groups (assimilation, segregation and exclusion) generally tend to be more discriminating than those who accept or approve of situations of cultural heterogeneity (integration of transformation, integration, individualism). Nevertheless, we observed an exception in the case of integrationist orientation. Integrationists massively reject explicitly hostile discrimination but tend to show "benevolent discrimination" (Fehr & Sassenberg, 2009). Studies 2 and 3 took place in a context of test/re-test, wich allowed us to measure the evolution of attitudes and the propensity to discriminate of insertion professionals, students and future state employees. The evolution was measured after several trainings which aimed at warning and fighting against discriminations. The "benevolent" discriminating behaviour intentions were particulary subject to evolution. All these results are in favour of implementing trainings on the decategorization process (Brewer and Miller, on 1984) which would consequently encourage individualism in certain circumstances, notably professional and/or organisational. The results might be enlarged studying the impact of the assimilationists policies on the efficiency of the state plans against discriminations.

L'assimilation de données, telle qu'elle s'est développée en particulier en météorologie ou en océanographie, désigne le processus par lequel on cherche à estimer de la manière la plus précise possible l'état atmosphérique ou océanique à partir d'observations et en s'appuyant sur un modèle de prévision. Le formalisme de l'assimilation peut être appréhendé de multiples manières. Il conduit à des algorithmes divers, mais présentant entre eux des liens aujourd'hui assez clairement établis. Une première partie des travaux présentés correspond au développement de techniques visant à améliorer la représentation des covariances d'erreur d'ébauche qui jouent un rôle important dans un schéma d'analyse. Une autre thématique traitée concerne le gain apporté par le 4D-Var sur la qualité des prévisions et des réanalyses d'expériences comme FASTEX. Nous présentons également des travaux associés au développement théorique et pratique de diagnostics des schémas d'assimilation. Il est montré comment ces diagnostics permettent aussi de mesurer l'impact des observations dans une analyse. Des perspectives d'évolution de l'assimilation de données sont enfin indiquées.

The performance of the ensemble Kalman filter (EnKF) in forced, dissipative flow under imperfect model conditions is investigated through simultaneous state and parameter estimation where the source of model error is the uncertainty in the model parameters. Two numerical models with increasing complexity are used with simulated observations. For lower complexity, a two-dimensional, nonlinear, hydrostatic, non-rotating, and incompressible sea breeze model is developed with buoyancy and vorticity as the prognostic variables. Model resolution is 4 km horizontally and 50 m vertically. The ensemble size is set at 40. Forcing is maintained through an explicit heating function with additive stochastic noise. Simulated buoyancy observations on land surface with 40-km spacing are assimilated every 3 hours. Up to six model parameters are successfully subjected to estimation attempts in various experiments. The overall EnKF performance in terms of the error statistics is found to be superior to the worst-case scenario (when there is parameter error but no parameter estimation is performed) with an average error reduction in buoyancy and vorticity of 40% and 46%, respectively, for the simultaneous estimation of six parameters. The model chosen to represent the complexity of operational weather forecasting is the Pennsylvania State University-National Center for Atmospheric Research MM5 model with a 36-km horizontal resolution and 43 vertical layers. The ensemble size for all experiments is chosen as 40 and a 41st member is generated as the truth with the same ensemble statistics. Assimilations are performed with a 12-hour interval with simulated sounding and surface observations of horizontal winds and temperature. Only single-parameter experiments are performed focusing on a constant inserted into the code as the multiplier of the vertical eddy mixing coefficient. Estimation experiments produce very encouraging results and the mean estimated parameter value nicely converges to the true value exhibiting a satisfactory level of variability.

Thesis--University of Washington. / Vita. Another copy has number: Thesis 26894. Bibliography: leaves [164]-169.

No description available.

It is generally accepted that models of the deep ocean must assimilate observations in order to make realistic forecasts in regions dominated by mesoscale variability (i.e., “ocean weather”). The present study is an attempt to quantify the information on ocean weather that is contained in Lagrangian trajectories, and the best way to extract it. Following a review of ocean data assimilation in a Bayesian framework, including the Ensemble Kalman Filter and the Particle Filter, a new class of idealized models of self advecting vortices is introduced. Through a large number of carefully designed Monte Carlo experiments it is shown when, where and why the Ensemble Kalman Filter will fail. The study concludes with a discussion of a hybrid scheme that takes advantage of the lower computational cost of the Ensemble Kalman Filter and the ability of the Particle Filter to handle highly non-Gaussian probability density functions. / MSc Thesis

This thesis presents an analysis of the phonological processes that affect contiguous nasal and obstruent segments. These phonological processes include voice, manner and place assimilation as well as deletion and coalescence. The goal of this thesis is to account for these seemingly disparate processes by introducing universal constraints on the representation of segments in non-linear phonology. Deriving these processes from the principles of a theory of representation is beneficial because such an analysis is not possible in a theory that appeals only to rules. The result is a theory of phonology with greater explanatory adequacy than a theory that relies on rules. / Chapter 1 contains a review of the history of the representation of segments and the representation of assimilation as well as a discussion of the theoretical assumptions used throughout the thesis. Chapter 2 contains a discussion of the phonological processes as they occur during the formation of prenasalized consonants. These processes are shown to be triggered by the representation of prenasalized consonants and a theory of underspecification. Chapter 3 proposes an analysis of the universal characteristics of nasal-obstruent place assimilation which is then extended to explain some universal properties of consonantal assimilation in general.

The Canadian Precipitation Analysis (CaPA) produces a gridded product by assimilating data from stations and the Global Environmental Multiscale (GEM) model. This project assesses the performance of the satellite based rainfall estimates for Canada, and the results of their assimilation with CaPA. The satellite based estimates considered are those from the Climate Prediction Center Morphing method (CMORPH) and Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN). Relative to the Second Generation of Daily Adjusted Precipitation for Canada (APC2), all satellite products are shown to generally underestimate rainfall, however convective events result in an overestimation. Skill scores show that the satellite products possess the most skill for eastern Canada and decreasingly so westward. When assimilated with CaPA, the satellite products express decreased skill for light rainfall and potential improvements for larger events. While central Canada experiences the greatest improvements, all regions benefit the most from June through August.

Thesis (Ph. D.)--University of Toronto, 2005. / Includes bibliographical references (leaves 356-391).

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2008. / Includes bibliographical references (leaves 49-53).