Une forte consommation d'énergie est un facteur clé impactant les performances des systèmes sur puce (SoC). Des modèles de puissance précis et efficaces doivent être introduits le plus tôt possible dans le flot de conception lorsque la majeure partie du potentiel d'optimisation est possible. Cependant, l'obtention d’une estimation précise ne peut être assurée en raison du manque de connaissance détaillées de la structure du circuit final. La conception actuelle de SoC repose sur la réutilisation de cœur IP (Intelectual Property) car des informations de bas niveau sur les composants du circuit ainsi que la structure sont disponibles. Ainsi, la précision de l'estimation au niveau du système peut être amélioré en utilisant ces informations et en élaborant une méthode d'estimation qui correspond aux besoins de modélisation de puissance des cœurs IP.La principale contribution de cette thèse est le développement d’une technique d'estimation hybride (HPET), dans laquelle les informations provenant de différents niveaux d'abstraction sont utilisées pour évaluer la consommation d'énergie de manière rapide et précise. HPET est basé sur une méthodologie efficace de caractérisation de la bibliothèque technologique et une approche hybride de modélisation de puissance. Les résultats des simulations obtenues avec HPET ont été validés sur différents circuits de référence synthétisés en utilisant la technologie 28nm "Fully Depleted Silicon On Insulator" (FDSOI). Les résultats expérimentaux montrent que nous pouvons atteindre en moyenne jusqu'à 70X d'amélioration en vitesse de calcul tout en ayant une précision au niveau transistor. Pour les deux types puissance analysés (instantanée et moyenne), les résultats de HPET sont bien corrélés par rapport à ceux calculés avec SPECTRE et Primetime-PX. Cela démontre que HPET est une technique efficace pour améliorer la création de macro-modèles de puissance à haut niveau d'abstraction. / High power consumption is a key factor hindering System-on-Chip (SoC) performance. Accurate and efficient power models have to be introduced early in the design flow when most of the optimization potential is possible. However, early accuracy cannot be ensured because of the lack of precise knowledge of the final circuit structure. Current SoC design paradigm relies on IP (Intellectual Property) core reuse since low-level information about circuit components and structure is available. Thus, power estimation accuracy at the system level can be improved by using this information and developing an estimation methodology that fits IP cores power modeling needs.The main contribution of this thesis is the development of a Hybrid Power Estimation Technique (HPET), in which, information coming from different abstraction levels is used to assess the power consumption in a fast and accurate manner. HPET is based on an effective characterization methodology of the technology library and an efficient hybrid power modeling approach. Experimental results, derived using HPET, have been validated on different benchmark circuits synthesized using the 28nm “Fully Depleted Silicon On Insulator” (FDSOI) technology. Experimental results show that in average we can achieve up to 70X speedup while having transistor-level accuracy. For both analyzed power types (instantaneous and average), HPET results are well correlated with respect to the ones computed in SPECTRE and Primetime-PX. This demonstrates that HPET is an effective technique to enhance power macro-modeling creation at high abstraction levels.

Yang, Kar Lai Alice. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese.

Avant la fondation de Rome, le chêne, le figuier et le cornouiller faisaient partie des essences d’arbres qui poussaient sur le territoire de la cité. Dans l’histoire des origines de Rome, le chêne d’Enée présageait déjà des destinées de la ville auxquelles donnera corps le figuier du Lupercal et celui du Comitium. Cependant, ce fut le cornouiller qui singularisa la création et l’élection de Rome, investie d’une mission civilisatrice universelle. La Cornus fut un des signes matériels des significations politique, sociale et religieuse des actes de Romulus, pourvoyeur de richesses, guerrier, et organisateur qui avait su transformer un lieu à demi forestier en une ville. Ces rôles, assumés par Romulus, répondent au schéma ternaire dégagé par G. Dumézil. Trois symboliques communes aux trois arbres se croisent : la notion de la constitution d’un peuple particulier dont les origines résultaient de la combinaison de peuples grecs et/ou italiques ; l’idée que ces arbres légendaires avaient été impliqués dans des actes de fondation ; enfin le rapport étroit entre une Rome mythique et la Rome des temps historiques que les arbres créent. La tradition sur la fondation de Rome qui a subi l’influence de la Grèce, s’est approprié cette ascendance pour en faire une histoire proprement romaine. Du chêne qui signifiait pour le Troyen Enée le terme de son voyage, puis du figuier, qui avait contribué à sauver Romulus en abritant la louve, jusqu’au cornouiller, poussé en haut du Palatin, les trois arbres mythiques ont symbolisé le lieu de la naissance de Rome et sont restés aux temps historiques des acteurs d’une civilisation urbanisée, regroupée en un seul peuple romain. / Before the founding of Rome by Romulus, oak, fig tree and dogwood were part of various tree species growing on the territory of Rome. In the history of the origins of the city, the oak of Aeneas already presaged the destinies of Rome to whom the lupercal fig tree will give body, it was the dogwood which illustrated the creation and election of Rome. The tree, or rather the shrub, was a material sign for political, social and religious meanings of the acts of Romulus in his threefold role as provider of wealth by the gathering of heterogeneous people, warrior who was given a place surrounded by forests, a veritable territory centered on a city, Rome, and deified King. Three symbolic notions common to the three founding trees crosses : the notion of an origin of the territory and the people that was based on an ancient pre-Roman, Greek and/or Italic ; the idea that these legendary trees had been involved in acts of fundation and creation of a people ; finally the close relationship between a mythical Rome and that of historical times, according to the tripartite scheme established by G. Dumézil. The Tradition on the founding of Rome was not exempt from Greek influence but had appropriated this Greek ancestry to make a proper Roman history. The oak, which meant the end of Trojan Aeneas journey, the fig tree which, with the wolf, had helped to save Romulus and the dogwood, pushed at the top of the Palatine Hill, in the middle of Roma Quadrata, the three trees symbolized the place of the birth of Rome, a city that gave a town and a civilization to a grouping of diverse populations before scattered in the woods.

An abstract of the thesis of Ben Huang for the Master of Science in Electric and Computer Science presented [August 12nd, 2010]. Title: Removing textured artifacts from digital photos by using spatial frequency filtering Virtually all image processing is now done with digital images. These images, captured with digital cameras, can be readily processed with various types of editing software to serve a multitude of personal and commercial purposes. But not all images are directly captured and even of those that are directly captured many are not of sufficiently high quality. Digital images are also acquired by scanning old paper images. The result is often a digital image of poor quality. Textured artifacts on some old paper pictures were designed to help protect pictures from discoloration. However, after scanning, these textured artifacts exhibit annoying textured noise in the digital image, highly degrading the visual definition of images on electronic screens. This kind of image noise is academically called global periodic noise. It is in a spurious and repetitive pattern that exists consistently throughout the image. There does not appear to be any commercial graphic software with a tool box to directly resolve this global periodic noise. Even Photoshop, considered to be the most powerful and authoritative graphic software, does not have an effective function to reduce textured noise. This thesis addresses this problem by proposing the use of an alternative graphic filter to what is currently available. To achieve the best image quality in photographic editing, spatial frequency domain filtering is utilized instead of spatial domain filtering. In frequency domain images, the consistent periodicity of the textured noise leads to well defined spikes in the frequency transform of the noisy image. When the noise spikes are at a sufficient distance from the image spectrum, they can be removed by reducing their frequency amplitudes. The filtered spectrum may then yield a noise reduced image through inverse frequency transforming. This thesis proposes a method to reduce periodic noise in the spatial frequency domain; summarizes the difference between DFT and DCT, FFT and fast DCT in image processing applications; uses fast DCT as the frequency transform to solve the problem in order to improve both computational load and filtered image quality; and develops software that can be implemented as a plug in for large graphic software to remove textured artifacts from digital images.

The potential use of sodium propionate as a corrosion inhibitor for mild steel in aqueous media is investigated using a range of electrochemical and surface analytical techniques. The use of sodium propionate for the inhibition of mild steel corrosion is discussed, and the effective pH range of sodium propionate using various buffers is investigated. The effectiveness of sodium propionate as an inhibitor for mild steel pitting corrosion in the presence of various concentrations of CI- is studied. The effect of some oxidants, IO3-, BrO3-, NO32- on the anodic behaviour of mild steel in deaerated 0.01M carboxylate solutions of acetate, propionate, formate, succinate and salicylate is investigated. The critical temperature for effective inhibition of mild steel corrosion with sodium propionate is established, and the chemical composition of the film formed on mild steel surface in sodium propionate solution is studied using surface sensitive Fourier transform infrared spectroscopy FTIR. The efficiency of sodium propionate is compared to that of conventional inhibitors and a mechanism for the inhibition of mild steel corrosion with sodium propionate is proposed. / Doctor of Philosophy (PhD)

Boundary value problems required for modelling plane wave propagation in electrically anisotropic and inhomogeneous media relevant to the surface impedance methods in electromagnetic geophysics are formally posed and treated. For a homogeneous TM-type wave propagating in a half space with both vertical and horizontal inhomogeneities where the TM-type wave is aligned with one of the elements of the conductivity tensor, it is shown using exact solutions that the shearing term in the homogeneous Helmholtz equation for inclined anisotropic media: [Equation 1], unequivocally vanishes and solutions need only be sought to the homogeneous Helmholtz equation for biaxial media: [Equation 2]. This implies that those problems posed with an inclined uniaxial conductivity tensor can be identically stated with a fundamental biaxial conductivity tensor, provided that the conductivity values are the reciprocal of the diagonal terms from the Euler rotated resistivity tensor: [Equation 3], [Equation 4], [Equation 5]. The applications of this consequence for numerical methods of solving arbitrary two-dimensional problems for a homogeneous TM-type wave is that they need only to approximate the homogeneous Helmholtz equation and neglect the corresponding shearing term. The self-consistent impedance method, a two-dimensional finite-difference approximation based on a network analogy, is demonstrated to accurately solve for problems with inclined uniaxial anisotropy using the fundamental biaxial anisotropy equivalence. The problem of a homogeneous plane wave at skew incidence upon an inclined anisotropic half space is then formally treated. In the half space, both TM- and TE-type waves are coupled and the linearly polarised incident TM- and TE-type waves reflect TE- and TM-type components. Equations for all elements of the impedance tensor are derived for both TM- and TE-type incidence. This offers potential as a method of predicting the direction of anisotropic strike from tensor impedance measurements in sedimentary environments.

<p>The total population of GPS-enabled location-based services (LBS) subscribers is constantly increasing. This fact implies new research possibilities for visualizing geospatial data produced by these mobile devices. The aim of this thesis is to explore novel techniques and methods to visualize the content of voice notes (messages recorded by users on GPS-enabled devices) that will be placed in maps using GPS coordinates, and visualize the semantical, temporal, and spatial relations between the notes. Our research is part of the Geovisualization field which deals with geospatial data.</p><p>Based on our research and analyzes of this problem, we combined different visualization and interaction techniques, thus providing a novel approach to achieve the research aim. We have built a prototype application, called GNV System (GeoAudio Notes Visualization System), that demonstrates our achievements.</p>

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