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Analysis of topography induced flow variations along the Gao-Ping Submarine Canyon based on hydrographic observationsGau, Ming-Shiung 29 April 2011 (has links)
This study investigates the hydrodynamic variations along the Gao-ping Submarine Canyon influence by the topography effects. The data used in this study were collected from two cruises of field observations using research vessel OR3. Instruments applied include sb-ADCP¡Bbm-ADCP¡Bmoored-ADCP¡BCTD and several vertical strings of temperature loggers. Parameters recorded include flow velocities, water temperature and tidal elevation. The analysis method is enlightenment by the case study in the Monterey Canyon of California.
The results show that (1) the current speed in the lower layer is faster than that of upper layer, which is explained due to v-shape of topography and bottom-trapped effect of internal tide. This result is consistent with previous studies. (2) In flood tide, the currents flowed into the Canyon from deep water to shallower. The baroclinic kinetic energy decreased to 0.2 at the turning point of canyon axis at 230m water, whichwas caused mainly by bottom friction. On the other hand, the baroclinic kinetic energy increased to 0.47 at 250m water in ebb tide when there was less influence of bottom friction. (3) In comparison the effects of bottom slope and area of cross section of the canyon, the baroclinic kinetic energy dissipation was mainly occurred at up slope flow during the flood tide. The change of the canyon width had less influence. During the ebb, the baroclinic kinetic energy was mainly due to the change of canyon width in the region shallower then the 230m of the second turning of the canyon. (4) The loss of kinetic energy during flooding up slope current can be verified by the changes of water mass temperature. Cold bottom was raised to upper layer when there was large drop of kinetic energy. There was likely a conversion of kinetic energy to potential energy. No upwelled cold water detected during ebb current with increase of kinetic energy.
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The topography effect to the flow variation in the coastal region of Nan-bin,HualienChang, Yu-Hung 21 October 2011 (has links)
This study investigates the hydrodynamic variations in the coastal region of Nan-bin, Hualien influence by the topography and water stratification. The data used were collected from four cruises of field observations in 2008/4/29¡B2008/9/5~6¡B2009/3/17~18 and 2009/7/21. Instruments applied include sb-ADCP and CTD. Parameters recorded include flow velocities, water temperature and salinity and tidal elevations. The collected data are analyzed through a variety of time series analysis technique, including buoyancy frequency EOF analysis, potential vorticity and kinetic energy.
The results show that (1) the flow field and vorticity in the south side of Hualien Harbor indicate there exist a counterclockwise eddy during flood. The flow pattern reverse to be a clockwise eddy during ebb. The current speed and vorticity is smaller in the surface layer, while the bottom current speed and vorticity is much larger. (2) Currents in transects of along slope, along canyon and along shore all reveal two layers flow separated around 25m, with upper layer flowing eastward and lower layer westward. The current velocity reaches to a maximum at 55m, and the current directions were dominated by the orientation of bottom topography. The baroclinic kinetic energy increase to 0.15m2/s2 along the down slope transect, while the up slope kinetic energy reduced to 0.05m2/s2. (3) The CTD data suggest that the upper layer is warm-fresh water due to river outputs, while the lower layer is dominated by cold-salty open ocean water. (4) The density interface at 25 m is confirmed by buoyance frequency analysis. The EOF analysis of density distribution shows eigenvalue of first mode has maximum at 53m, while the second mode has peaks at 25m and 65m, which match well with the vertical of distribution of flow structures.
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Etude de la stabilité et de la précision des modèles utilisés dans la correction des effets de proximité optique en photolithographie / Study of the impact of different physical parameters during OPC model creation for 65nm and 45nm technologiesSaied, Mazen 30 September 2011 (has links)
À l’heure actuelle, les modèles photochimiques utilisés dans la correction des effets de proximitéoptique (OPC) en photolithographie sont devenus complexes et moins physiques afin de permettre decapturer rapidement le maximum d’effets optiques et chimiques. La question de la stabilité de tels modèlespurement empiriques est devenue d’actualité. Dans ce mémoire, nous avons étudié la stabilité desmodèles photochimiques actuels en examinant les différentes causes d’instabilité vis-à-vis des paramètresdu procédé. Dans la suite, nous avons développé une méthode perturbative permettant d’évaluer le critèrede la stabilité. L’obtention de modèles simples et stables nous conduit à séparer les effets optiques desautres effets chimiques. De plus, les approximations utilisées dans la modélisation des systèmes optiquesopérant à grande ouverture numérique entraînent des erreurs résiduelles pouvant dégrader la précisionet la stabilité des modèles OPC. Ainsi, nous nous sommes intéressés à étudier les limites de validitéde l’approximation de Kirchhoff, méthode qui, jusqu’à présent, est la plus utilisée dans la modélisationdu champ proche d’un masque. D’autres méthodes semi-rigoureuses, permettant de modéliser les effetstopographiques, ont été également évaluées. Ces méthodes approchées permettent de gagner en précisionmais dégradent le temps de calcul. Nous avons ainsi proposé différentes façons de corriger les effetstopographiques du masque, tout en gardant l’approximation de Kirchhoff dans la modélisation de la partieoptique. Parmi les méthodes proposées, nous exploitons celle permettant de réduire les erreurs liéesaux effets topographiques du masque par l’intermédiaire d’un second modèle empirique. Nous montronsque pour garantir une précision adéquate, il est nécessaire d’augmenter la complexité du modèle en rajoutantdes termes additionnels. Enfin, pour garantir la stabilité numérique du modèle empirique, nousintroduirons une nouvelle méthode approchée hybride rapide et précise, la méthode des multi-niveaux,permettant d’inclure les effets topographiques par décomposition multi-niveaux du masque fin et discuteronsses avantages et ses limites. / At present, common resist models utilized in photolithography to correct for optical proximity effects(OPC) became complex and less physical in order to capture the maximum of optical and chemical effectsin shorter times. The question on the stability of such models, purely empirical, become topical. In thisthesis, we study the stability of existing OPC models by examining the origins of model instability towardsprocess parameters. Thus, we have developed a perturbative method in order to evaluate the stabilitycriterion. However, achieving stable and simple models needs a separation between optical and otherchemical effects. Besides, multiple approximations, widely utilized in the modeling of optical systemsoperating at high numerical aperture, lead to residual errors which can degrade OPC model accuracyand stability. Thus, we were interested to study the limits of validity of the Kirchhoff approximation,a method which, so far, is the most commonly used in mask near-field modeling. Other semi-rigorousmethods for mask topography effect modeling were also evaluated. These approximate methods canimprove the accuracy but degrades the run time. We then suggested different techniques to correct formask topography effects, while keeping the Kirchhoff approximation in the modeling of the optical part.Among them, we showed that errors due to mask topography effects can be partially captured by asecond empirical model. However, in order to ensure a good accuracy, it is necessary to increase themodel complexity by using more additional empirical terms. Finally, in order to achieve a numericalstability of the empirical model, we introduced a new hybrid fast and accurate method, the multi-levelmethod, which allows us to correct for mask topography effects through a multi-level decomposition ofthe thin mask and discussed its advantages and drawbacks.
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