Thesis (Ph. D.)--University of Alberta, 2010. / Title from pdf file main screen (viewed on June 24, 2010). A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Applied Mathematics, Department of Mathematical and Statistical Sciences, University of Alberta. Includes bibliographical references.

Thesis (M.S.)--University of Missouri-Columbia, 2004. / Typescript. Includes bibliographical references (leaves 58-61). Also available on the Internet.

Thesis (Ph. D.)--University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 18, 2006) Vita. Includes bibliographical references.

Thesis (M.Phil.)--Hong Kong University of Science and Technology, 2006. / Includes bibliographical references (leaves 90-94). Also available in electronic version.

University, Diss., 2004--Bonn.

Thesis (MSc (Mathematics))--Stellenbosch University, 2008. / See full text for abstract.

Ce travail de thèse consiste à utiliser les données satellitaires de SST (température de surface), SSS (salinité de surface), et Chl-a (chlorophylle-a), pour l’interpolation de la fugacité du CO2 (fCO2) dans la couche de surface de l’océan Atlantique tropical, pour les saisons de la période 2002-2013. Trois types de données ont été utilisés : in situ (BD (base de données) SOCAT V.3) ; satellitaires (capteurs : MODIS-A, Sea-WIFS, et SMOS) ; et assimilées (BD SODA V.2.2.4). La première étape était la classification des données en se basant sur la SST. La deuxième étape était l’interpolation de la fCO2 (pour chaque classe de chaque saison), en utilisant des RNs (réseaux de neurones artificiels) de type feedforward, avec un apprentissage de type backpropagation. Les résultats obtenus (RMSEs (root mean square error) variant de 8,8 à 15,7 µatm) permettent de confirmer l’importance de : traiter les saisons séparément, classifier les données, et choisir le meilleur RN en fonction des résultats de la généralisation. Ceci a permis l’élaboration de 138 fichiers CSV (Comma-separated values) de fCO2 mensuelle, avec une résolution de 4 km x 4 km, pour la période allant de juillet 2002 à décembre 2013. / This thesis work consists of using satellite data of SST (sea surface temperature), SSS (sea surface salinity), and Chl-a (chlorophyll-a), in order to interpolate the CO2 fugacity (fCO2) in the surface of the tropical Atlantic ocean, for seasons of the period 2002-2013. Three data types were used: in situ (SOCAT V.3 DB (database)); satellite (MODIS-A, Sea-WIFS, and SMOS sensors); and assimilated (SODA V.2.2.4 DB). The first step was the data classification based on SST. The second step was the fCO2 interpolation (for each class of each season), using feedforward NNs (artificial neural networks) with a backpropagation learning method. Obtained results (RMSEs (root mean square error) between 8,8 and 15,7 µatm) confirm the importance of: process each season separately, pass through data classification step, and choose the best NN on the basis of generalization step results. This allowed the development of 138 monthly fCO2 CSV (Comma-separated values) file, with 4 km x 4 km spatial resolution, for the period from July 2002 to December 2013.

No description available.

Os objetivos deste trabalho são: i) Fixado um inteiro positivo n, estudar dois métodos "construtivos" para aproximar-se uma função real contínua definida na esfera unitária S ^{r-1} de R^r, por polinômios esféricos de grau <=n; ii) Obter estimativas para as normas dos operadores de interpolação e hiperinterpolação, comparando-as com a norma da projeção ortogonal de C(S^{r-1}) sobre o espaço de polinômios onde as aproximações residem. / This work addresses two issues: i) To study two constructive methods to approximate a real continuous function on the unit sphere S^{r-1} of R^r by spherical polynomials of degree <=n (n fixed); ii) To estimate the norms of the interpolation and hyperinterpolation operators, comparing them with the norm of the orthogonal projection of C(S^{r-1}) over the polynomial space where the approximations live.

Haptic, or force, interaction in virtual environments can support the development of physical manipulation skills if users feel realistic forces in response to their motion in the virtual environment. The realism of the forces felt by users depends on: (i) how accurately the virtual environment simulates a real life situation such as surgery; and (ii) how faithfully the haptic controller renders the simulated interactions to users. Accurate simulations of real life situations such as surgery run at variable frequencies of the order of 20-100 Hz. However, the haptic controller needs updated stiffness and direction of contact at 1000 Hz to faithfully convey the shape and hardness of the virtual objects to the user. This thesis proposes to bridge the gap between the required fast haptic control rate and the slower virtual environment updates through a passive local model of interaction. This model comprises an approximation of the shape and stiffness of the virtual world in the area near the point of interaction. It also monitors its exchange of energy with the user to ensure its own passivity and thus, the stability of the haptic system. Lastly, the local model eliminates the spurious discontinuities that arise in contact direction at model updates by interpolating the contact normal before rendering it to the user. / Graduate