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This work presents and investigates a novel high-performance antenna design for remote sensing and satellite communications applications that is compact and lightweight. The performance requirements include dual-polarization, wide impedance bandwidth, low cross-polarization, high gain, and high aperture efficiency. To simultaneously achieve all these qualities is challenging and a combination of compatible performance enhancement techniques was selected and derived. A new antenna design, namely an octagonal cavity-backed radiating open prism (OCROP) antenna, was first introduced. The antenna is orthogonally and differentially fed to provide dual-polarization and low cross-polarization. The impedance bandwidth is increased by combining the resonances from the radiating feedlines and the open prism. The corner truncated octagonal ground cavity, instead of a more commonly seen square ground plane or square ground cavity, is used to further suppress the cross-polarization and enhance the gain and aperture efficiency. To show the superiority of the octagonal design, it was compared with a square ground cavity backed antenna. To further improve the gain of this novel antenna, its array and flared configurations are considered, investigated, and compared. The array design offers higher gain and aperture efficiency, while the flared design can provide lower cross-polarization. To achieve higher gain with the flared design, a larger flare angle was chosen which increased cross-polarization. To remedy the problem of the increased cross-polarization, a new iris design concept is proposed and investigated. It shows that this method can successfully suppress the cross-polarization of the flared design. This concept is general and has the potential to be applied to other types of aperture antennas. The design concepts and the simulation results are verified by fabricating and testing two prototypes, i.e., with and without a flare.

Direct compounded compression molded carbon fibre long fibre thermoplastic (LFT-D) combines the high strength and stiffness of carbon fibre with a mass production manufacturing process intended to maximize fibre length. However, this process is more commonly used in industry with glass fibre. Extensive characterization of mechanical properties, spanning fundamental tensile tests to impact characterization of standard specimens and a complex automotive component, was completed to understand the strengths and deficiencies of this novel material formulation for engineering applications: fundamental uniaxial tension (quasi-static and intermediate strain rate) and three-point bending tests, tensile stress-life fatigue characterization, ISO 6603-2 instrumented impact of standard specimens, and quasi-static/low velocity impact loading of an automotive seating component. These studies provide the data necessary to advance commercial adoption of direct compounded long carbon fibre thermoplastic. Uniaxial tension and three-point bending characterization of 9% to 25% weight fraction compression molded carbon fibre LFT-D polyamide-6 was completed with orientations of 0°, ±45°, and 90°. A novel finding that has importance for process modelling was that uniaxial tension and flexural properties were higher in the +45° direction compared to –45° (tensile modulus: 20%, strength: 10%, flexural modulus: 8%). Correspondingly, engineering strain at failure for uniaxial tensile tests was 18% lower in the +45° direction. These observations are hypothesized to be the result of fibre orientation asymmetry in the compression molding charge due to the screw of the compounder. Tensile fatigue characterization was carried out for 40% (by weight) carbon fiber/polyamide 66 LFT-D composites. This characterization yielded fatigue stress-life curves (23 °C, dry as molded, R = 0.1, 3 Hz) for 0°, 45°, and 90° orientations with respect to flow. Peak stresses at which the samples achieved 1E6 cycles were 105 MPa for samples oriented in the flow direction, 72 MPa for samples oriented 45° to the flow direction, and 53 MPa for samples oriented 90° to flow. Poorly dispersed fibre with little to no wet-out were identified by SEM at the fracture surfaces for those specimens with fatigue properties near the stress-life lower bound. Further development of the direct compounding process is needed for carbon fibre. Direct/in-line compounded PA6/CF long fibre thermoplastic was also characterized under low velocity impact consistent with ISO standard 6603-2. Additionally, a quasi-static variant of the ISO method was employed to assess rate sensitivity. At quasi-static loading rates, flow region specimens were notably more brittle considering the force-deflection response. However, the energy absorption did not differ significantly between charge and flow region specimens. In terms of rate sensitivity, puncture energy under low velocity impact decreased by 18% on average with respect to quasi-static loading. Tensile specimens were extracted from an automotive seatback structure compression molded from PA66/CF. Additionally, quasi-static and low velocity impact loading of seatback components was completed. Under low velocity impact loading a local force maxima was observed for seatbacks produced with a longitudinal charge orientation. No local maxima were consistently observed for transverse charge seatbacks. In terms of rate effects: initial stiffness was 550% higher for low velocity impact with respect to quasi-static loading. Digital image correlation identified localized deformation at the hemispherical indenter for low-velocity impact indicating an inertial component to the rate sensitivity. Catastrophic failure occurred at larger deflections for low velocity impact (36% increase for longitudinal charge placement, 24% for transverse). A study of specimen size effect for quasi-static uniaxial tension puncture test was completed for compression molded direct compounded carbon fibre LFT. No significant size effects were observed for the elastic modulus or tensile strength obtained from tensile specimens with four different gauge lengths (6.25 mm to 57 mm). The failure strain decreased by 27.5% and 29.9%, respectively, across the gauge length range for the 0°/90° directions. This material was also characterized at intermediate strain rates (10 s–1 to 100 s–1) through uniaxial tension tests on a novel apparatus and ISO 6603-2 puncture tests. Intermediate strain rate tensile tests showed little to no strain rate sensitivity for the 0° and 90° directions. However, initial stiffness was approximately 50% higher for ISO 6603-2 impact tests compared to quasi-static puncture tests.

We address the question of how the approximation error/Bellman residual at each iteration of the Approximate Policy/Value Iteration algorithms influences the quality of the resulted policy. We quantify the performance loss as the Lp norm of the approximation error/Bellman residual at each iteration. Moreover, we show that the performance loss depends on the expectation of the squared Radon-Nikodym derivative of a certain distribution rather than its supremum as opposed to what has been suggested by the previous results. Also our results indicate that the contribution of the approximation/Bellman error to the performance loss is more prominent in the later iterations of API/AVI, and the effect of an error term in the earlier iterations decays exponentially fast. International audience

Poster presented at SETAC Europe's 33rd Annual Meeting held in Dublin Ireland..

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Stream flow in Minnesota: Indicator\nof climate change. J. Hydrology 334, 319- 333\n[45] Serreze, M.C., Bromwich, D.H., Clark, M.P., Etringer, A.J., Zhang, T.,\nLammers, R. 2003. Large-scale hydro-climatology of the terrestrial\nArctic drainage system. Journal of Geophysical Research 107, 8160.\ndoi:10.1029/2001JD000919.\n[46] Singh, P., Kumar, V., Thomas, T., and Arora, M. 2008. Basin-wide\nassessment of temperature trends in northwest and central India.\nHydrological Science Journal, 53(2), 421-433\n[47] Stewart, I.T., Cayan, D.R., Dettinger, M.D. 2005. Changes towards\nearlier streamflow timing across western North America. J. Climate 18,\n1136-1155\n[48] von Storch, H., Zwiers, F.W. 1999. Statistical Analysis in Climate\nResearch. Cambridge University Press, Cambridge.\n[49] Westmacott, J.R., Burn, D.H. 1997. Climate change effects on the\nhydrologic regime within the Churchill-Nelson River Basin. J.\nHydrology 202, 263-279.\n[50] Whitfield, P.H., 2001. Linked hydrologic and climatic variations in\nBritish Columbia and Yukon. Environmental Monitoring and\nAssessment 67(1-2), 217-238.\n[51] Woolhiser, D. A., T. O. Keefer, Redmond, K.T. 1993. Southern\noscillation effects on daily precipitation in the southwestern united\nStates, Water Resour. Res., 29, 1287-1295.\n[52] Yue, S., Pilon, P.J., Phinney, B. and Cavadias, G. 2002. The influence\nof autocorrelation on the ability to detect trend in hydrological series. J.\nHydrological Processes 16(9): 1807-1829.\n[53] Zhang,Q., Liu,C., XU, C.Y., XU, Y.P., Jiang, T. 2006. Observed trends\nof water level and Streamflow during past 100 years in the Yangtze\nRiver basin, China, J. Hydrolgy 324 (1-4).255-265\n[54] Zhang,X., Harvey, K.D., Hogg, W.D., Yuzyk, T.R. 2001. Trends in\nCanadian streamflow. Water Resouces Research 37 (4), 987-998.\n[55] Zhang Q, Liu C, Xu CY, Xu YP, Jiang, T. 2006. Observed trends of\nwater level and streamflow during past 100 years in the Yangtze River\nbasin, China. J. Hydrology 324 (1-4): 255-265"]} Large scale climate signals and their teleconnections can influence hydro-meteorological variables on a local scale. Several extreme flow and timing measures, including high flow and low flow measures, from 62 hydrometric stations in Canada are investigated to detect possible linkages with several large scale climate indices. The streamflow data used in this study are derived from the Canadian Reference Hydrometric Basin Network and are characterized by relatively pristine and stable land-use conditions with a minimum of 40 years of record. A composite analysis approach was used to identify linkages between extreme flow and timing measures and climate indices. The approach involves determining the 10 highest and 10 lowest values of various climate indices from the data record. Extreme flow and timing measures for each station were examined for the years associated with the 10 largest values and the years associated with the 10 smallest values. In each case, a re-sampling approach was applied to determine if the 10 values of extreme flow measures differed significantly from the series mean. Results indicate that several stations are impacted by the large scale climate indices considered in this study. The results allow the determination of any relationship between stations that exhibit a statistically significant trend and stations for which the extreme measures exhibit a linkage with the climate indices.

Background: Every phenotypic trait can be viewed as a “system” in which a group of interconnected componentsfunction synergistically to yield a unified whole. Once a system’s components and their interactions have beendelineated according to biological principles, we can manipulate and engineer functionally relevant components toproduce a desirable system phenotype.Results: We describe a conceptual framework for mapping quantitative trait loci (QTLs) that control complex traitsby treating trait formation as a dynamic system. This framework, called systems mapping, incorporates a system ofdifferential equations that quantifies how alterations of different components lead to the global change of traitdevelopment and function through genes, and provides a quantitative and testable platform for assessing theinterplay between gene action and development. We applied systems mapping to analyze biomass growth data ina mapping population of soybeans and identified specific loci that are responsible for the dynamics of biomasspartitioning to leaves, stem, and roots.Conclusions: We show that systems mapping implemented by design principles of biological systems is quiteversatile for deciphering the genetic machineries for size-shape, structural-functional, sink-source and pleiotropicrelationships underlying plant physiology and development. Systems mapping should enable geneticists to shedlight on the genetic complexity of any biological system in plants and other organisms and predict itsphysiological and pathological states.

The Deep Underground Neutrino Experiment (DUNE) is a next-generation long-baseline neutrino oscillation experiment with a primary physics goal of observing neutrino and antineutrino oscillation patterns to precisely measure the parameters governing long-baseline neutrino oscillation in a single experiment, and to test the three-flavor paradigm. DUNE's design has been developed by a large, international collaboration of scientists and engineers to have unique capability to measure neutrino oscillation as a function of energy in a broadband beam, to resolve degeneracy among oscillation parameters, and to control systematic uncertainty using the exquisite imaging capability of massive LArTPC far detector modules and an argon-based near detector. DUNE's neutrino oscillation measurements will unambiguously resolve the neutrino mass ordering and provide the sensitivity to discover CP violation in neutrinos for a wide range of possible values of $\delta_{CP}$. DUNE is also uniquely sensitive to electron neutrinos from a galactic supernova burst, and to a broad range of physics beyond the Standard Model (BSM), including nucleon decays. DUNE is anticipated to begin collecting physics data with Phase I, an initial experiment configuration consisting of two far detector modules and a minimal suite of near detector components, with a 1.2 MW proton beam. To realize its extensive, world-leading physics potential requires the full scope of DUNE be completed in Phase II. The three Phase II upgrades are all necessary to achieve DUNE's physics goals: (1) addition of far detector modules three and four for a total FD fiducial mass of at least 40 kt, (2) upgrade of the proton beam power from 1.2 MW to 2.4 MW, and (3) replacement of the near detector's temporary muon spectrometer with a magnetized, high-pressure gaseous argon TPC and calorimeter.

Les gens consacrent une importante part de leur existence à prendre diverses décisions, pouvant affecter leur demande en transport, par exemple les choix de lieux d'habitation et de travail, les modes de transport, les heures de départ, le nombre et type de voitures dans le ménage, les itinéraires ... Les choix liés au transport sont généralement fonction du temps et caractérisés par un grand nombre de solutions alternatives qui peuvent être spatialement corrélées. Cette thèse traite de modèles pouvant être utilisés pour analyser et prédire les choix discrets dans les applications liées aux réseaux de grandes tailles. Les modèles et méthodes proposées sont particulièrement pertinents pour les applications en transport, sans toutefois s'y limiter. Nous modélisons les décisions comme des séquences de choix, dans le cadre des choix discrets dynamiques, aussi connus comme processus de décision de Markov paramétriques. Ces modèles sont réputés difficiles à estimer et à appliquer en prédiction, puisque le calcul des probabilités de choix requiert la résolution de problèmes de programmation dynamique. Nous montrons dans cette thèse qu'il est possible d'exploiter la structure du réseau et la flexibilité de la programmation dynamique afin de rendre l'approche de modélisation dynamique en choix discrets non seulement utile pour représenter les choix dépendant du temps, mais également pour modéliser plus facilement des choix statiques au sein d'ensembles de choix de très grande taille. La thèse se compose de sept articles, présentant divers modèles et méthodes d'estimation, leur application ainsi que des expériences numériques sur des modèles de choix discrets de grande taille. Nous regroupons les contributions en trois principales thématiques: modélisation du choix de route, estimation de modèles en valeur extrême multivariée (MEV) de grande taille et algorithmes d'optimisation non-linéaire. Cinq articles sont associés à la modélisation de choix de route. Nous proposons différents modèles de choix discrets dynamiques permettant aux utilités des chemins d'être corrélées, sur base de formulations MEV et logit mixte. Les modèles résultants devenant coûteux à estimer, nous présentons de nouvelles approches permettant de diminuer les efforts de calcul. Nous proposons par exemple une méthode de décomposition qui non seulement ouvre la possibilité d'estimer efficacement des modèles logit mixte, mais également d'accélérer l'estimation de modèles simples comme les modèles logit multinomiaux, ce qui a également des implications en simulation de trafic. De plus, nous comparons les règles de décision basées sur le principe de maximisation d'utilité de celles sur la minimisation du regret pour ce type de modèles. Nous proposons finalement un test statistique sur les erreurs de spécification pour les modèles de choix de route basés sur le logit multinomial. Le second thème porte sur l'estimation de modèles de choix discrets statiques avec de grands ensembles de choix. Nous établissons que certains types de modèles MEV peuvent être reformulés comme des modèles de choix discrets dynamiques, construits sur des réseaux de structure de corrélation. Ces modèles peuvent alors être estimées rapidement en utilisant des techniques de programmation dynamique en combinaison avec un algorithme efficace d'optimisation non-linéaire. La troisième et dernière thématique concerne les algorithmes d'optimisation non-linéaires dans le cadre de l'estimation de modèles complexes de choix discrets par maximum de vraisemblance. Nous examinons et adaptons des méthodes quasi-Newton structurées qui peuvent être facilement intégrées dans des algorithmes d'optimisation usuels (recherche linéaire et région de confiance) afin d'accélérer le processus d'estimation. Les modèles de choix discrets dynamiques et les méthodes d'optimisation proposés peuvent être employés dans diverses applications de choix discrets. Dans le domaine des sciences de données, des modèles qui peuvent traiter de grands ensembles de choix et des ensembles de choix séquentiels sont importants. Nos recherches peuvent dès lors être d'intérêt dans diverses applications d'analyse de la demande (analyse prédictive) ou peuvent être intégrées à des modèles d'optimisation (analyse prescriptive). De plus, nos études mettent en évidence le potentiel des techniques de programmation dynamique dans ce contexte, y compris pour des modèles statiques, ouvrant la voie à de multiples directions de recherche future. People go through their life making all kinds of decisions, and some of these decisions affect their demand for transportation, for example, their choices of where to live and where to work, how and when to travel and which route to take. Transport related choices are typically time dependent and characterized by large number of alternatives that can be spatially correlated. This thesis deals with models that can be used to analyze and predict discrete choices in large-scale networks. The proposed models and methods are highly relevant for, but not limited to, transport applications. We model decisions as sequences of choices within the dynamic discrete choice framework, also known as parametric Markov decision processes. Such models are known to be difficult to estimate and to apply to make predictions because dynamic programming problems need to be solved in order to compute choice probabilities. In this thesis we show that it is possible to explore the network structure and the flexibility of dynamic programming so that the dynamic discrete choice modeling approach is not only useful to model time dependent choices, but also makes it easier to model large-scale static choices. The thesis consists of seven articles containing a number of models and methods for estimating, applying and testing large-scale discrete choice models. In the following we group the contributions under three themes: route choice modeling, large-scale multivariate extreme value (MEV) model estimation and nonlinear optimization algorithms. Five articles are related to route choice modeling. We propose different dynamic discrete choice models that allow paths to be correlated based on the MEV and mixed logit models. The resulting route choice models become expensive to estimate and we deal with this challenge by proposing innovative methods that allow to reduce the estimation cost. For example, we propose a decomposition method that not only opens up for possibility of mixing, but also speeds up the estimation for simple logit models, which has implications also for traffic simulation. Moreover, we compare the utility maximization and regret minimization decision rules, and we propose a misspecification test for logit-based route choice models. The second theme is related to the estimation of static discrete choice models with large choice sets. We establish that a class of MEV models can be reformulated as dynamic discrete choice models on the networks of correlation structures. These dynamic models can then be estimated quickly using dynamic programming techniques and an efficient nonlinear optimization algorithm. Finally, the third theme focuses on structured quasi-Newton techniques for estimating discrete choice models by maximum likelihood. We examine and adapt switching methods that can be easily integrated into usual optimization algorithms (line search and trust region) to accelerate the estimation process. The proposed dynamic discrete choice models and estimation methods can be used in various discrete choice applications. In the area of big data analytics, models that can deal with large choice sets and sequential choices are important. Our research can therefore be of interest in various demand analysis applications (predictive analytics) or can be integrated with optimization models (prescriptive analytics). Furthermore, our studies indicate the potential of dynamic programming techniques in this context, even for static models, which opens up a variety of future research directions.