La recherche en physique des particules recouvre des activités diverses depuis la conception des expériences, la mise en route et le suivi des détecteurs, le traitement des données et leur analyse, jusqu'à la communication des résultats aux scientifiques et au grand public. Le document illustre différentes facettes de cette recherche via: la description de la grille de calcul et de stockage qui permet le traitement des données enregistrées par les expériences du LHC et en particulier par l'expérience ATLAS; une mesure de la section efficace top-antitop avec l'expérience D0 auprès du Tevatron; la description de quelques actions de diffusion des connaissances auprès du grand public.

The role of the neutron-proton asymmetry (isospin) in the de-excitation of excited nuclei is investigated by studying the isospin dependence of the Ar+Ni fusion-evaporation cross sections. Compound nuclei of Pd, with mass number varying from 92 (close to the limit of stability for proton emission) to 104 (stable), are produced with the same excitation energy (~3 MeV/nucleon), impinging stable and radioactive Ar beams with energies around 13 MeV/nucleon on to isotopically enriched Ni targets. The de-excitation products are collected by the VAMOS magnetic spectrometer and the 4pi charged particle array INDRA. The study shows a decrease of the Ar+Ni fusion-evaporation cross section as the isospin of the system decreases, suggesting that the deexcitation of excited Pd nuclei is influenced by their neutron-proton asymmetry. Also, a larger decrease is observed for the N = Z 92Pd nucleus, explained as the opening of a new de-excitation channel (multifragmentation).

In the present PhD work, three sophisticated models based on the "Engineering" modeling approach have been utilized to conveniently describe and thoroughly analyze details of Lightning events at the CN Tower. Both the CN Tower and the Lightning Channel are represented by a number of connected in series Transmission Line sections in order to account for the variations in the shape of the tower and for plasma processes that take place within the Lightning Channel. A sum of two Heidler functions is used to describe the "uncontaminated" Return Stroke current, which is injected at the attachment point between the CN Tower and the Lightning Channel. Reflections and refractions at all points of mismatched impedances are considered until their contribution becomes less than 1% of the originally injected current wave. In the proposed models, the problem with the current discontinuity at the Lightning Channel front, commonly taken care of by introducing a "turn-on" term when computing radiation fields, is uniquely treated by introducing reflected and transmitted components. For the first time, variable speed of propagation of the Return Stroke current front has been considered and its influence upon the predicted current distributions along the whole Lightning Channel path and upon the radiated distant fields analyzed. Furthermore, as another novelty, computation of the electromagnetic field is accomplished in Cartesian Coordinates. This fact permits to relax the requirement on the verticality of the Lightning Channel, normally imposed in Cylindrical Coordinates. Therefore, it becomes possible to study without difficulty the influence of a slanted Lightning Channel upon the surrounding electromagnetic field. Since the proposed sophisticated Five-Section Model has the capability to represent very closely the structure of the CN Tower and to emulate faithfully the shape of, as well as physical processes within the Lightning Channel, it is believed to have the potential of truthfully reproducing observed fields. The developed modeling approach can be easily adapted to study the anticipated radiated fields at tall structures even before construction.

This study explores the underlying causes and deterrent control mechanisms of police misconduct in the United States. Outcomes of causes and control mechanisms constitute the basis for an applicable model for the Turkish National Police (TNP). Why is some police behavior deviate? What are the main determinants of police misconduct? Is police misconduct a result of sociological behavior and subcultural development within police organizations or a psychological behavior as an outcome of officers' personal traits? What are the control mechanisms for police misconduct? What are their strengths and weaknesses? Do they deter or not? Is there a control mechanism that deters better than others? What is the best deterrence model for the TNP?

Die Kaiserschnittrate erhöhte sich in den letzten Jahrzehnten in zahlreichen geburtshilflichen Kliniken. Diese Entwicklung ist problematisch, weil damit eine erhöhte pulmonale Morbidität der Neugeborenen verbunden sein kann. Die vor­ liegende Arbeit untersucht die Anpassung von späten Frühgeborenen (34,0–36,6 SSW) und 2 Gruppen von reifen Neugeborenen (37,0–37,6 und 40,6–40,6 SSW) in einem Level 1 Zentrum in Abhängigkeit vom Geburtsmodus. Eingeschlos­ sen wurden primär gesunde Kinder, die im Verlauf eines Jahres geboren wurden. Ausge­ schlossen wurden Kinder mit nachgewiesener angeborener Anomalie und Kinder mit einer schweren Anpassungsstörung (Apgar 5‘<6). Die Kaiserschnittrate lag bei 22% und war am höch­ sten bei späten Frühgeborenen (39%) im Ver­ gleich zu Kindern der 37. (30 %) und der 40. SSW (11%). Die Rate der Kinder, die mit CPAP behan­ delt werden mussten fiel von 88 % in der 34. SSW auf 17% in der 37. und 8% in der 40. SSW. Kinder nach Kaiserschnitt mussten im Vergleich zur spontan geborenen Kindern signifikant häufiger mit CPAP therapiert werden (50 vs. 12%). Dieser Unterschied war für späte Frühgeborene deutlich (82 vs. 36 %) und lag niedriger bei in der 37. (33 vs. 9 %) und 40. (26 vs. 6 %) SSW geborenen Kindern. Der deutlichste Unterschied fiel bei in der 36. SSW geborenen Kindern auf (66 vs. 9%). Die Ergebnisse der Analyse dokumentieren, dass ein Kaiserschnitt bei primär gesunden Kindern zu einer schlechteren respiratorischen Anpassung führt. Dies gilt besonders, jedoch nicht nur, für späte Frühgeborene und dort besonders für Kinder, die in der 36. SSW geboren werden. Die weltweit wachsende Rate von Kaiserschnittent­ bindungen sollte immer wieder kritisch hinter­ fragt werden. Eine Kaiserschnittentbindung ohne klare Indikation führt zu einer erhöhten Rate an respiratorischen Anpassungsstörungen, zur neo­ natologischen Aufnahme der Kinder und damit verbunden zu einer Störung der Mutter­Kind­Bindung, sowie zu einer unnötigen finanziellen Belastung des Gesundheitssystems. Es ist zu wünschen, dass die Daten der Studie benutzt werden, um in der Diskussion zwischen Eltern, Geburtshelfern und Neo­ natologen immer den besten Geburtsweg für das Kind zu finden. / The rates of delivery by Cesarean section (CS) have been trending upwards in recent decades, perhaps leading to higher rates of dysfunction in respiratory adaptation in newborns. We present epidemiological data for pulmonary adaptation by mode of delivery for healthy late preterm and term infants born at a regional tertiary care center. The overall CS rate was 22 % with the lar­ gest proportion of these in late preterms (39%). This drops to 30% in infants born after 37 weeks gestation and to 11% for those born after 40 weeks. Infants needing respiratory support de­ creased significantly as gestational age increased: 88% at 34 weeks, 67% at 35 weeks, 28% at 36 weeks, 17% at 37 weeks and 8% at 40 weeks. The risk of respiratory morbidity following CS as compared to vaginal delivery (VD) was substan­ tially higher. 50% of infants born by CS needed respiratory support compared to only 12% fol­ lowing VD. 82% of all late preterm infants born by CS developed respiratory morbidity compared to 36 % following VD. Comparable data for infants born after 37 and 40 weeks gestation were 33% compared to 9 % and 26 % compared to 6 % respec­ tively. Late preterm infants born after 36 weeks gestation showed the most marked difference by mode of birth with 66 % needing respiratory sup­ port following CS as compared to only 9 % follow­ ing VD. Our data could be useful in counselling parents about risk associated with delivery by Cesarean section. A critical view should be taken of increasing CS rates worldwide because of a clear correlation in increased morbidity in infants, especially late preterm infants.

A sharp increase in caesarean section (CS) rates at the Muhimbili National Referral Hospital (MNH) – a tertiary referral hospital in Tanzania – by 50% in 2000–2011, was associated with concomitant increase in maternal complications and deaths and inconsistent improvement in newborn outcomes. The aims of this thesis were to explore care providers’ in-depth perspective of the reasons for these high rates of CS, and to evaluate and improve standards of care for the most common indica-tions of CS, obstructed labour and fetal distress, which are also major causes of adverse maternal and neonatal outcomes. This thesis reports an investigation performed at MNH, Tanzania. For Paper I, qualitative methods were employed and demonstrated how care providers dismissed their responsibility for the rising CS rate; and, instead, projected the causes onto factors beyond their control. Additionally, dysfunctinal teamwork, transparency, and previous poorly conducted clinical audits led to fear of blame among care providers in cases of poor outcome that subsequently encougared defensive practise by assigning unnecessary CS. Papers II and III evaluated stand-ards of care using a criteria-based audit (CBA) of obstructed labour and fetal dis-tress. After implementing audit-feedback recommendations, the standards of diag-nosis of fetal distress improved by 16% and obstructed labour by 7%. Similarly, the standards of management preceding CS improved tenfold for fetal distress and doubled for obstructed labour. The impact of the CBA process was evaluated by comparing the maternal and perinatal outcomes categorized into Robson groups (Paper IV) of all deliveries occurring before and after the audit process (n=27,960). After the CBA process, there was a 50% risk reduction of severe perinatal morbidi-ty/mortality for patients with obstructed labour. The overall CS rates increased by 10%, and this was attributed to an increase in the CS rate among breech, term preg-nancies (Robson group 6), and preterm pregnancies (Robson group 10) that specifi-cally had reduced risk of poor perinatal outcome. The overall neonatal distress rates were also reduced by 20%, and this was attributed to a decrease in the neonatal distress rate among low-risk, term pregnancies (Robson group 3). Importantly, the increased rates of poor perinatal outcomes were associated with referred patients that had higher risk of neonatal distress and PMR than non–referred patients, after CBA process.  In conclusion, the studies managed to educate the care providers to take on their roles as decision-makers and medical experts to minimize unnecessary CS, using the available resources. Care providers’ commitment to achieve the best practice should be sustained and effort for stepwise upgrading quality of obstetric care should be supported by the hospital management from the primary to tertiary referral level.

Large wind turbine blades, manufactured from fibre reinforced laminated composite materials, are key structural components of wind turbine systems. The demands for efficient and accurate modelling techniques of these composite blades have significantly increased. Over past decades, although complex computational models have been widely developed, more analytically based models are still very much desired to drive the design and optimization of these composite blades forward to be lighter, stronger, efficient and durable. The research work in this thesis aims to develop such more analytically based aerodynamic, structural and aero-elasticity models for large wind turbine blades manufactured from fibre reinforced laminated composite materials. Firstly, an improved blade element momentum (BEM) model has been developed by collectively integrating the individual corrections with the classic BEM model. Compared to other existing models, present BEM model accounts for blade tip and root losses more accurately. For laminar flow, the 3-D cross-flow is negligibly small. In this case, present BEM model with statically measured 2-D aerodynamic coefficients agrees closely to experimental measurements. However, stall delay correction is required for a 3-D rotating blade in stall. A new stall delay model is developed based on Snel s stall delay model. Verifications are performed and discussed for the extensively studied NREL UAE phase-VI test. The predictions of distributive and collective factors, e.g. normalised force coefficients, shaft torque and etc. have been compared to experimental measurements. The present BEM model and stall delay model are original and more accurate than existing models. Secondly, significant deficiency is discovered in the analytical thin-walled closed-section composite beam (TWCSCB) model proposed by Librescu and Vo, which is widely used by others for structural modelling of wind turbine blades. To correct such deficiency, an improved TWCSCB model is developed in a novel manner that is applicable to both single-cell and multi-cell closed sections made of arbitrary composite laminates. The present TWCSCB model has been validated for a variety of geometries and arbitrary laminate layups. The numerical verifications are also performed on a realistic wind turbine blade (NPS-100) for structural analysis. Consistently accurate correlations are found between present TWCSCB model and the ABAQUS finite element (FE) shell model. Finally, the static aero-elasticity model is developed by combining the developed BEM model and TWCSCB model. The interactions are accounted through an iterative process. The numerical applications are carried out on NPS-100 wind turbine. The numerical results show some significant corrections by modelling wind turbine blades with elastic coupling.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

In June of 2015, the U.S. Department of Housing and Urban Development released an Advance Notice of Proposed Rulemaking to establish a more effective Fair Market Rent System using Small Area Fair Market Rents (SAFMRs) in the Housing Choice Voucher Program (HCVP) instead of the current 50th Percentile FMRs. The 50th Percentile FMR is currently in use in the Richmond, Virginia region, and the region is likely to be among early adopters of the new SAFMR System. This thesis assesses existing conditions that will affect implementation of the Small Area Fair Market Rent (SAFMR) System. First, it evaluates where voucher holders have located and concentrated with limited mobility counseling and without the SAFMR System intervention. Second, this evaluation assesses the theory of opportunity and targeting metrics currently in use by the local Move to Opportunity Program administered in the region, because the SAFMR System has a stated objective to enable voucher holders to de-concentrate from low opportunity areas. Finally, this evaluation assesses the SAFMR System’s potential for value capture, estimating total savings and a discrete number of potential new vouchers that may be created with those savings. This research attempts to answer these dimensions of SAFMR System implementation by evaluating key characteristics of current voucher holder concentration in the metropolitan region.

Les tests de dispositifs de communication sans fil peuvent être réalisés en utilisant des simulations numériques ou des sondeurs de canaux. Bien que ne reflétant pas un environnement électromagnétique réaliste, une chambre réverbérante peut néanmoins émuler un canal de propagation comparable à un cas réel si l’on modifie convenablement ses propriétés. Les propriétés des signaux générés dans une chambre réverbérante sont fonction de différents paramètres. Au cours des trois années de thèse, nous avons analysé et mis en oeuvre plusieurs techniques pour mesurer et contrôler ces paramètres à l’intérieur d’une chambre réverbérante. D’abord, différents estimateurs du facteur K sont testés et leurs propriétés sont évaluées. Nous présentons les limites de fonctionnement utiles dans lesquelles différents estimateurspeuvent être utilisés. Ensuite, nous proposons deux nouveaux estimateurs qui utilisent comme données d’entrée seulement l’enveloppe du signal. Ils apportent en outre des améliorations sur la gamme des valeurs détectables du facteur K. Une des possibilités pour contrôler un canal de propagation à l’intérieur d’une chambre réverbérante est d’utiliser des matériaux absorbants. Nous présentons une méthode pour estimer la surface équivalente moyenne d’absorption en utilisant une seule antenne. Cette méthode exploite la mesure de la bande de cohérence du canal de propagation. Ensuite, nous étendons notre analyse à la prédiction de la surface équivalente moyenne d’absorption lorsqueles dimensions géométriques et les propriétés électromagnétiques des absorbants sont connues. On crée ensuite un modèle de canal de propagation en exploitant les régimes transitoire et permanent du signal. Avec ce modèle, selon les informations disponibles, on peut extraire le facteur K, la surface équivalente moyenne d’absorption et différents paramètres temporels (i.e., profil de l’étalement des retards). Nous poursuivons avec deux applications possibles des chambres réverbérantes. Tout d’abord, on évalue le gain d’une antenne à partir de mesures du coefficient de réflexion decette antenne. Nous étendons notre analyse à l’évaluation du diagramme de rayonnement de l’antenne et de son erreur d’estimation. Nous estimons aussi la désadaptation de l’antenne et son ouverture à 3 dB. La deuxième application porte sur l’évaluation du gain de diversité dans la chambre réverbérante. Nous isolons les influences des efficacités des antennes, des puissances des composantes brassées, et des facteurs K sur l’évaluation du gain de diversité.On obtient une relation simple de la corrélation de puissance en fonction de la corrélation complexe lorsque les facteurs K sur différents branches ne sont pas identiques. Nous montrons que lors d’un fort déséquilibre de facteur K il est impossible de conclure sur le gain de diversité à partir de la seule évaluation de la corrélation d’enveloppe ou de puissance. À l’aide de simulations statistiques on compare le gain de diversité mesuré avec les valeurs simulées. / The testing of wireless devices is generally done using numerical simulations or channel sounders. Though a reverberation chamber does not reflect a real transmission environment, its properties can also be appropriately modifiedto emulate one. This emulation may be achieved thanks to various parameters. Our PhD thesis has been devoted toanalyze and implement several techniques to measure and control these parameters inside reverberation chambers.First we evaluate different K-factor estimators and their capabilities. We present the useful limits in which severalcomplex, phase and envelope K-factor estimators can be used. Then, we propose two new envelope-based estimatorsimproving the useful range of detectable values of K-factor. One of the possibilities to control a propagation channel inside areverberation chamber is to use absorbing materials. We present a method to estimate the average absorbing crosssection by using only one antenna. This is done with measurements of coherence bandwidth of the channel. Then,we extend our analysis to predict the average absorbing cross section when we know the physical dimensions of aparallelepiped absorber as well its electromagnetic properties. Next, we create a model of the reverberation chamberpropagation channel using the transient regime and steady state of the signal. With this model, depending on the availableinformation, we can extract the K-factor, the average absorbing cross section and different time spreads parameters (i.e., mean delay spread and the root mean square delay spread). We continue with two possible applications of the reverberation chamber. First, we evaluate the gain of an antenna from only the measurement of reflection coefficient. We extend our analysis to the evaluation of antenna pattern and its estimation errors. We also estimate the antenna mismatch and half power beamwidth. The second application deals with the evaluation of the diversity gain in reverberation chamber. We isolate the effects on the diversity gain due to different antenna efficiencies, stirred powers and K-factors. Then, we estimate a simple relation of the power correlation as a function of the complex correlation when the K-factors on different branches are not identical. We show that using an envelope/power correlation as a criterion to characterize the diversity may bias the conclusions without taking into account other parameters. Using statistical simulations we compare the measured diversity gain with the simulated values.