Les labels présents sur les emballages (e.g., « bio », « commerce équitable ») peuvent pousser les individus à sous-évaluer le contenu calorique des aliments, créant ainsi un effet de halo santé. Dans cette thèse, nous défendons l’idée qu’un mécanisme de fausse attribution affective pourrait en partie expliquer cet effet de halo santé. Nous présenterons 11 études ayant pour but de tester empiriquement cette hypothèse. Parmi les principaux résultats, nous avons montré qu’il était possible d’observer cet effet même si les individus ne rapportent pas avoir pris en compte le label dans leur évaluation (Etudes 3) et dans un contexte de double tâche entravant un raisonnement délibéré de leur part (Etudes 4 et 5). Nous avons également pu montrer, par le biais d’une tâche de fausse attribution affective, qu’un stimulus neutre, lorsqu’il est précédé d’un label bio (vs. une image contrôle) est ensuite évalué plus positivement (Etudes 6, 7 et 8). Enfin, nous avons observé une congruence systématique entre la valence de l’amorce (i.e., le label) et la valence de l’évaluation subséquente d’un stimulus neutre (i.e., le contenu calorique d’un produit alimentaire ; Etudes 9, 10 et 11). Ce biais cognitif relatif à nos évaluations caloriques apparaît donc comme un phénomène robuste, ne faisant intervenir que peu d’inférences délibérées de la part des individus et étant guidé par la valence du label (qu’il soit positif ou négatif). / Labels on food products can lead to unwarranted inferences: organic and fair-trade products are perceived as containing fewer calories. This effect is described in the literature as the health halo effect. In this thesis, we argue that an affective misattribution mechanism can partially explain this effect. We present 11 studies testing empirically this hypothesis.Among our main results, we show that this effect still occurs even if participants did not mention that they used the label in their evaluation (Study 3) and when they are under cognitive load, hindering a deliberate reasoning (Studies 4 and 5). By using an affective misattribution procedure, we also show that when a neutral stimulus is preceded by an organic label (vs. a control picture), this stimulus is then evaluated more positively (Studies 6, 7, and 8). Finally, we observed a systematic congruency between the valence of the prime (i.e., the label) and the valence of the evaluation of a neutral stimulus (i.e., the caloric content of a food product; Studies 9, 10, and 11). Taken together, these studies suggest that this cognitive bias is a robust phenomenon, involving a few inferences and mainly driven by the valence of the label (whether positive or negative).

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This thesis examines charging of electric vehicles with charging power of 3,7 kW, in connection to an apartment building in Sweden. Also the power consumption of six electric vehicles are investigated. The charging-simulations of the electric vehicles were performed with the electric vehicle charging model (Grahn-Munkhammar) in MatLab. To simulate general energy use for a housing complex, the measured energy consumption per year for a building with 24 apartments was used. Three different systems with charging over a year were simulated. One system included six different models of electric vehicles, another system included six Tesla model S and yet another one included six Mitsubishi Outlanders. The simulations of electric vehicle charging resulted in a charging pattern with a considerable variability and an aggregation effect with a value over 20 % for all three systems. Results show that electric vehicle charging adds to the power peaks of the apartment building. However, according to the model, the aggregation effect implies that effect values of total electric vehicle charging were not harmful to an apartment building with a fuse of 63 A.

This dissertation describes our efforts to use the assembly of matter on nuclear scales as a probe of the assembly of matter on Galactic scales. To investigate the former, we characterize the detailed abundance patterns of the heaviest elements found in ancient, metal-poor stars in the Galaxy. In particular, we place new constraints on and identify several new correlations among the nuclei produced by the rapid nucleosynthetic process, which we use to refine current models of the physical conditions of this process. To investigate the latter, we apply our knowledge of stellar nucleosynthesis to examine correlations between the space motions of stars and their compositions, which retain a record of the composition of the interstellar medium where they formed many billions of years ago. Using new high quality stellar spectra collected from McDonald Observatory and Las Campanas Observatory, we confirm the relative chemical homogeneity of a well-known stellar stream and identify several chemical differences between the two major components of the stellar halo of the Galaxy. Each of these results has significant implications for our understanding of how the Galactic halo formed, grew, and evolved. More profoundly, these results indicate that we have not yet fully characterized the cosmic origins of the heaviest elements in the universe and that we will likely need to examine large samples of metal-poor stars at great distances from the Sun to potentially do so. / text

This research uses a Bayesian approach to study the biases that may occur when kinematic data is used to estimate the mass of a galaxy. Data is simulated from the Hernquist (1990) distribution functions (DFs) for velocity dispersions of the isotropic, constant anisotropic, and anisotropic Osipkov (1979) and Merritt (1985) type, and then analysed using the isotropic Hernquist model. Biases are explored when i) the model and data come from the same DF, ii) the model and data come from the same DF but tangential velocities are unknown, iii) the model and data come from different DFs, and iv) the model and data come from different DFs and the tangential velocities are unknown. Mock observations are also created from the Gauthier (2006) simulations and analysed with the isotropic Hernquist model. No bias was found in situation (i), a slight positive bias was found in (ii), a negative bias was found in (iii), and a large positive bias was found in (iv). The mass estimate of the Gauthier system when tangential velocities were unknown was nearly correct, but the mass profile was not described well by the isotropic Hernquist model. When the Gauthier data was analysed with the tangential velocities, the mass of the system was overestimated. The code created for the research runs three parallel Markov Chains for each data set, uses the Gelman-Rubin statistic to assess convergence, and combines the converged chains into a single sample of the posterior distribution for each data set. The code also includes two ways to deal with nuisance parameters. One is to marginalize over the nuisance parameter at every step in the chain, and the other is to sample the nuisance parameters using a hybrid-Gibbs sampler. When tangential velocities, v(t), are unobserved in the analyses above, they are sampled as nuisance parameters in the Markov Chain. The v(t) estimates from the Markov chains did a poor job of estimating the true tangential velocities. However, the posterior samples of v(t) proved to be useful, as the estimates of the tangential velocities helped explain the biases discovered in situations (i)-(iv) above. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2013-03-26 17:23:14.643

Approved for public release, distribution is unlimited / A Halo orbit about a libration point of a restricted three-body system provides additional opportunities for surveillance, communication, and exploratory missions in lieu of the classical spacecraft orbit. Historically libration point missions have focused on Halo orbits and trajectories about the Sun-Earth System. This thesis will focus on libration point orbit solutions in the Earth-Moon system using the restricted three body equations of motion with three low-thrust control functions. These classical dynamics are used to design and optimize orbital trajectories about stable and unstable libration points of the Earth-Moon system using DIDO, a dynamic optimization software. The solutions for the optimized performance are based on a quadratic cost function. Specific constraints and bounds were placed on the potential solution set in order to ensure correct target trajectories. This approach revealed locally optimal solutions for orbits about a stable and unstable libration point. / Lieutenant, United States Navy

We motivate the importance of understanding the kinematics and dynamics of the Milky Way stellar halo both in unravelling the formation history and evolution of our host Galaxy and in the more general context of galaxy dynamics. We present a cleaned picture of the kinematics of the smooth component of the stellar halo: we develop a method to quantify the average distance error on a sample of stars based on the idea of Schoenrich et al. (2012), but adapted so that it uses velocity information only on average. We use this scheme to construct an analytic distance calibration for Blue Horizontal Branch (BHB) field halo stars in Sloan colours and demonstrate that our calibration is a) more accurate than the ones available and b) unbiased w.r.t. metallicity and colour. We measure the rotation of the smooth component of the stellar halo with a tool-set of four estimators that use either only the l.o.s. velocities or the full 3D motion. From two samples of BHB stars from the Sloan Digital Sky Survey, we favour a non-rotating single halo. We critique conflicting results in the literature based on similar samples and trace back the disagreement (either in the sign of rotation or in the morphology of the halo) to sample contaminations and/or neglect account of the halo geometry. We propose a scheme that generalizes any isotropic spherical model to a model where the potential is axisymmetric and the distribution function is a function of the three actions. The idea is to approximate the Hamiltonian as a function of the actions with a library of quadratic fits to surfaces of constant energy in action space and then make explicit the dependence of the energy on the three actions in the ergodic distribution function. The transparency of the physics implied by the model we achieve, should make it possible to combine our spheroidal models to the f(J)-models of Binney (2010) for the disks and of Pontzen & Governato (2013) for the dark-matter halo, and obtain a complete actions-defined dynamical model of the Milky Way Galaxy.

Formation of globular clusters (GCs), the Galactic bulge, or galaxy bulges in general is an important unsolved problem in Galactic astronomy. Homogeneous infrared observations of large samples of stars belonging to GCs and the Galactic bulge field are one of the best ways to study these problems. We report the discovery by APOGEE (Apache Point Observatory Galactic Evolution Experiment) of a population of field stars in the inner Galaxy with abundances of N, C, and Al that are typically found in GC stars. The newly discovered stars have high [N/Fe], which is correlated with [Al/Fe] and anticorrelated with [C/Fe]. They are homogeneously distributed across, and kinematically indistinguishable from, other field stars within the same volume. Their metallicity distribution is seemingly unimodal, peaking at [Fe/H] similar to -1, thus being in disagreement with that of the Galactic GC system. Our results can be understood in terms of different scenarios. N-rich stars could be former members of dissolved GCs, in which case the mass in destroyed GCs exceeds that of the surviving GC system by a factor of similar to 8. In that scenario, the total mass contained in so-called 'first-generation' stars cannot be larger than that in 'second-generation' stars by more than a factor of similar to 9 and was certainly smaller. Conversely, our results may imply the absence of a mandatory genetic link between 'second-generation' stars and GCs. Last, but not least, N-rich stars could be the oldest stars in the Galaxy, the by-products of chemical enrichment by the first stellar generations formed in the heart of the Galaxy.

The purpose of this study was to determine if leniency and halo error in student ratings could be reduced by training the student raters and by using a Behaviorally Anchored Rating Scale (BARS) rather than a Likert scale. Two hypotheses were proposed. First, the ratings collected from the trained raters would contain less halo and leniency error than those collected from the untrained raters. Second, within the group of trained raters the BARS would contain less halo and leniency error than the Likert instrument.