L'intégration tridimensionnelle (3D), où plusieurs puces sont empilées et interconnectées, est en train de révolutionner l'industrie des semi-conducteurs.Cette technologie permet d'associer, dans un même boîtier, des puces électroniques (analogique, numérique, mémoire) avec des puces d'autres domaines(MEMS, bio-capteurs, optique, etc). Cela ouvre de nombreuses voies d'innovation. Néanmoins, l'absence d'outils de conception assistée ordinateur(CAO) adaptés aux systèmes 3D freine l'adoption de la technologie.Cette thèse contribue à deux problématiques liées à la conception 3D : le partitionnement d'un système sur de multiples puces et l'optimisation hiérarchique de systèmes multiphysiques (hétérogènes).La première partie de la thèse est dédiée au problème de partitionner la fonctionnalité d'un système sur de multiples puces. Un outil de « floorplan » 3D a été développé pour optimiser ce partitionnement en fonction de la surface des puces, de la température d'opération du circuit et de la structure des interconnexions. Ce type d'outil étant complexe, nous proposons de régler ses paramètres de façon automatique par l'utilisation d'algorithmes évolutionnaires.Des résultats expérimentaux sur une suite de benchmarks et sur une architecture multi processeur connecté en réseau démontrent l'efficacité et l'applicabilité des techniques d'optimisation proposées.Dans la deuxième partie, nous présentons une méthodologie de conception hiérarchique qui est adaptée aux systèmes hétérogènes. La méthode combine une approche ascendante et descendante et utilise des courbes de compromis(Fronts de Pareto) comme une abstraction de la performance d'un circuit.La contribution principale de la thèse consiste à utiliser des techniques d'interpolation pour représenter les Fronts de Pareto par des fonctions continues et à leur intégration dans des processus d'optimisation classiques. Cela permet un gain en flexibilité lors de l'étape ascendante du flot (caractérisation) et un gain en temps lors de l'étape descendante (synthèse). Le flot de conception est démontré sur un amplificateur opérationnel ainsi comme sur la synthèse d'un lien optoélectronique avec trois niveaux hiérarchiques. / 3D integration technology is driving a strong paradigm shift in the design of electronic systems. The ability to tightly integrate functions from different technology nodes (analog, digital, memory) and physical domains (MEMS, optics, etc) offers great opportunities for innovation (More than Moore). However, leveraging this potential requires efficient CAD tools to compare architectural choices at early design stages and to co-optimize multiphysics systems.This thesis work is divided into two parts. The first part is dedicated to the problem of partitioning a system into multiple dies. A 3D floorplanning tool was developed to optimize area, temperature and the interconnect structure of a 3DIC. Moreover, a meta-optimization approach based on genetic algorithms is proposed to automatically configure the key parameters of the floorplanner. Tests were carried out on architectural benchmarks and a NoC based multiprocessor to demonstrate the efficiency of the proposed techniques.In the second part of the thesis, a hierarchical design methodology adapted to heterogeneous systems is presented. The method combines the bottom-up and top-down approaches with Pareto-front techniques and response surface modeling. The Pareto front of lower level blocks are extracted and converted into predictive performance models that can be stored and reused in a top-down optimization process. The design flow is demonstrated on an operational amplifier as well as on the synthesis of an optoelectronic data link with three abstraction levels.

This dissertation presents results for two separate problems, both in the context of variational fracture models. The first problem involved developing and analyzing models of fracture in which we modeled the energy dissipated by crack growth as concentrated on the front of the crack. While many engineering models of fracture are based on a notion of crack front, there had not been a rigorous definition. We present the first work in this area, which includes a natural weak definition of crack front and front speed, a model of fracture whose evolution is described at the crack front, and a relaxation result that shows that these front based dissipations are all effectively equivalent to a Griffith-type dissipation. The second problem involved the computation of stationary points for Mumford-Shah and fracture using a level set method. Our method improves on existing techniques in that it can handle tips in the singular set and can find minimizers that previous techniques are unable to resolve.

Seismic reflection surveying is used to generate acoustic images of the water column. This technique employs conventional multi-channel equipment which is used to image the solid Earth. In the water column, acoustic impedance contrasts are produced by variations in temperature and, to some extent, salinity. Acoustic impulses generated by an array of airguns suspended behind a vessel are reflected from these contrasts and recorded on long cables of hydrophones that are towed below the sea-surface. In this way, two- and three-dimensional images of thermohaline circulation can be generated. Critically, these images have equal vertical and horizontal resolutions of \textit{O}(10)~m. Here, I describe, process, and analyse a calibrated two-dimensional seismic survey from the Bellingshausen Sea of the Southern Ocean and a three-dimensional seismic survey from the Brazil-Falkland Confluence located offshore Uruguay. First, the Bellingshausen survey was designed to image the thermohaline structure across the west Antarctic shelf where warm-core eddies are reported. Processed and calibrated seismic images reveal the detailed thermohaline structure of Circumpolar Deep Water. Many warm-core eddies are observed, which have diameters of 1--12~km and thicknesses of 100--200~m. Pre-stack analysis demonstrates that this eddy field is being advected onto the shelf at speeds of \textit{O}(0.1)~m~s$^{-1}$. An iterative inverse modelling procedure is used to convert reflectivity into temperature and salinity, which confirms that the eddies have anomalously warm centres (i.e. $\sim$1$^{\circ}$C). These results have significant implications for ice shelf melting. Secondly, the Uruguay survey is used to investigate a large-scale frontal system. Although this system has been studied using hydrographic methods, these studies either have limited spatial resolution or have restricted depth penetration. The three-dimensional seismic survey, which was acquired in a `racetrack' pattern, permits the volume to be interrogated. Since the frontal system migrates southwestwards at a speed of \textit{O}(10)~km~day$^{-1}$, this survey is time-lapse in nature. Processed images reveal a band of dipping reflections that extend to depths of $\sim$2000~m. These reflections represent the frontal interface between the Brazil and Falkland currents. Physical oceanographic properties are calculated for images that cross this front. On the warm side of the front, the water mass is characterised by flat and continuous reflectivity. On the cold side of the front, the water mass is characterised by deformed reflectivity on all scales. Pre-stack analysis suggests that near-surface flow at the frontal interface is convergent. Between 0.5 and 1~km depth, a substantial eddy that is 30~km long and 250~m thick is visible on the cold side of the front. Detailed mapping suggests that this eddy grew and decayed over a period of 6~days. Its observed scale and duration are inconsistent with analytical and numerical studies of intra-thermocline eddies. Nevertheless, its duration is consistent with scaling arguments of frictional spin-down. Spatial and temporal distributions of mixing rates (i.e. diapycnal diffusivities) are estimated by spectrally analysing vertical displacements of automatically tracked reflections. Both internal wave and turbulent regimes are identifiable. Recovered diapycnal diffusivities are of \textit{O}($10^{-6}$--$10^{-2.2}$)~m$^{2}$~s$^{-1}$, consistent with hydrographically determined estimates. Mixing is suppressed and enhanced on the warm and cold sides of the front, respectively. Seismic Oceanography has considerable potential to quantify aspects of thermohaline circulation on multiple scales.

Five line transect surveys for marine mammals were conducted offshore of mainland Ecuador and the Galápagos Islands from 2008-2011. These data were used in conjunction with MODIS (Moderate Resolution Imaging Spectroradiometer) observations of ocean color and sea surface temperature (SST) to assess spatial and temporal relationships between surface oceanographic features and cetacean distribution within the Eastern Equatorial Pacific (EEP). Results from this study indicated that oceanographic processes affected cetacean distribution on inter-annual, seasonal, and weekly to monthly time scales. The spatial scales on which these processes affect cetacean distribution are small, the smallest associations being found at 4 km2 bin sizes, as well as 9 km2 and 36 km2 bin sizes. By utilizing ocean color and SST data from the MODIS instrument and analyzing variability of these parameters in addition to average concentration, cetacean distribution within the region was related to the locations of frontal boundaries. Cetaceans were grouped into two categories based on the trophic level and relative depths at which they forage. Cetaceans feeding nearer the ocean surface and lower on the trophic scale were generally found in cooler waters of higher average chlorophyll concentration and elevated variability. Those cetaceans feeding higher on the trophic scale and lower in the water column (mesopelagic and bathypelagic depths) were sighted within relatively warmer waters of reduced temperature variability near areas of high chlorophyll variability (though less variable and lower in average chlorophyll than surface feeding cetaceans), with little spatial and temporal lag between peak surface chlorophyll concentration and cetacean presence. The EEP is a biologically productive region with many competing economic and environmental interests. Ecuador is home to one of the largest artisenal fishing fleets in South America, and entanglement of various cetacean species has been a known issue for several decades (Félix and Haase, 2006; Castro and Rosero, 2010). Seismic exploration, shipping, and tourism are also found on the busy waterways surrounding both mainland Ecuador and the archipelago. The results of this study provide additional insight into the mesoscale processes affecting the distribution and habitat use of cetaceans within the EEP and South American waters and to support ongoing ecosystem management efforts.

Satellite images of chlorophyll concentration in the surface waters of the Gulf of Mexico suggest a high degree of heterogeneity in the phytoplankton biomass. The causes of this variability and the amount of variability in the phytoplankton community structure are not well understood. The physical and chemical conditions of a specific environment can influence phytoplankton community structure by selecting for those phytoplankton species able to survive within that environment. Varying salinity and temperature characteristics give water masses distinct surface water density signatures. This study examined the relationship between phytoplankton biomass, community structure, and different water mass properties by measuring chlorophyll a and algal group concentration across frontal zones. Continuous salinity and temperature measurements were used to calculate continuous density along transects during four cruises on the R/V Gyre between summer 2002 and spring 2004. Frontal zones were identified as areas of sharp density change where σt changed by 1.5 points over a distance of 1 km. Density fronts that coincided with visible temperature fronts (satellite AVHRR images) were selected for biomass and community structure analysis. Discrete water samples were analyzed using fluorometric analysis (total chlorophyll a concentration) and HPLC analysis (photosynthetic pigments). Community composition for discrete samples was determined using CHEMTAX and these values were used to interpolate community composition. Phytoplankton biomass and community structure were examined at a total of 21 density fronts. Unlike previous studies of frontal zones, phytoplankton biomass (measured as chl a concentration) was not significantly higher within frontal zones than in adjacent waters at any of the 21 fronts. Community composition (measured as algal group abundance and diversity) was significantly different between the front and at least one adjacent water mass at front 2 during summer 2002, at front 6 during summer 2003, at front 3 during fall 2003, and at front 3 during spring 2004. Both biomass and community composition were significantly different between fronts at all front pairs during summer 2002. The results of this study suggest that density fronts are not biologically important features in the northern Gulf of Mexico. Lack of high phytoplankton biomass at fronts in the Gulf of Mexico could indicate that unique physical, chemical, or biological processes are occurring.

Addendum inserted onto front end-paper. / Bibliography: p. 261-284. / xv, 284 p. : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Provides a thorough analysis of cut-off low phenomena over Australia by using the VHF radar system, operating at a frequency of 54.1MHz / Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1999

Thesis (M.Eng.Sc.)--University of Adelaide, Dept. of Physics and Mathematical Physics, 1999. / Addendum inserted onto front end-paper. Bibliography: p. 261-284.

Thesis (Ph. D.)--Florida State University, 1981. / Includes bibliographical references (leaves 90-92).

Thesis (Ph. D.)--York University, 2004. Graduate Programme in Music. / Typescript. Includes bibliographical references (leaves 346-367). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNQ99266.

The larvae of coastal species interact with nearshore currents that are complex and can alter dispersal. I investigated two sites in southern Oregon with different nearshore hydrodynamics: the first site, Sunset Bay, is a small cove with a topographic front that extends across the mouth during upwelling-favorable winds. Using holey sock drogues at 1.5 m and 5.5 m depths and surface drifters at 10 cm depth, I found that, when the front was present, water at 1.5 m was retained within the bay whereas water was exchanged across the front at a depth of 5.5 m. Surface drifters indicated a surface convergence. Surface plankton tows on either side and within the frontal convergence (a shore-parallel foam line) found significantly higher concentrations of barnacle cyprids, crab megalopae and zoea, polychaete larvae, platyhelminthes juveniles, isopods, amphipods, harpacticoid copepods, and fish eggs. Crustacean nauplii (barnacle, euphausiid, and copepod) and calanoid copepods were not concentrated in the convergence, and when the front and foam line were absent, no taxa were concentrated. Plankton tows taken within the foam line as it dissipated shoreward during a wind-reversal event found that concentrations of cyprids, megalopae, and gastropod veligers remained high as the foam line moved, suggesting that it acts as a moving convergence propagating competent larvae shoreward. I measured settlement of two taxa at Sunset Bay and Shore Acres, an open-coast site <2 km away. Barnacle settlement measured every other day from June-September 2013 was significantly cross-correlated with the maximum daily tidal height at lags of -2 days at Sunset Bay and +2 and +4 days at Shore Acres. Settlement was also significantly negatively cross-correlated with wave height at a lag of -4 days at Sunset Bay. Coralline algae settlement measured during eight 48-hr periods in July-August 2013 was significantly negatively correlated with wave height (n = 8, R2 = 0.76, P = 0.0049) at Shore Acres but not at Sunset Bay. Despite the close proximity of the Sunset Bay and Shore Acres sites, settlement patterns differed between taxa, suggesting that differences in nearshore hydrodynamics might affect the supply of water and larvae to shore. This dissertation includes unpublished co-authored material.