1,721,139 research outputs found
A differential game theory approach to DC-DC buck converter control
Get PDFTribunal: Prof. Rafael Canetti, Prof. Eleonora Catsigeras (Universidad de la República), Prof. Martin Ordonez (University of British Columbia, Canadá).This thesis deals with the problem of controlling a generic synchronous buck converter against unpredictable, and possibly discontinuous, but bounded load disturbances. The problem is canonically framed as a dynamical conflict between the automatic controller in charge of the output voltage regulation and an hypothetical disturber. In particular, the conflict is regarded as a pursuit-evasion game in distance. Applying classical methods of differential game theory, the game is
completely solved identifing three qualitative different cases that can take place depending on how a positive derived parameter value compares to unity. The game’s solution provides optimal strategies for the controller and the disturber which can be used, respectively, for worst-case-aware control and benchmark testing (of any control method). Furthermore, from the topography of the game’s value function, qualitative and quantitative information about the physical limits of buck converter control is gained, allowing for early design stage optimization of the converter’s LC filter towards regulation performance, regardless of the control method that might finally be selected.Esta tesis aborda el problema de controlar un convertidor sincrónico tipo buck genérico frente a perturbaciones impredecibles, y posiblemente discontinuas, pero acotadas de la corriente de carga. El problema se plantea en forma canónica como un conflicto dinámico entre el controlador automático encargado de la regulación del voltaje de salida y un perturbador hipotético. En particular, el conflicto es visto como un juego de persecusión-evasión en distancia. Aplicando métodos clásicos de la teoría de juegos diferenciales, el juego es completamente resuelto identificando tres casos cualitativamente distintos que pueden ocurrir dependiendo de si el valor de un parámetro derivado positivo es menor, igual, o mayor que uno. La solución del juego provee estrategias óptimas para el controlador y para el perturbador que pueden ser utilizadas, respectivamente, para implementar control ante el peor caso y para realizar pruebas de referencia (aplicables a cualquier método de control). Además, de la topografía de la función valor del juego, se obtiene información cualitativa y cuantitativa acerca de los límites físicos inherentes al control de convertidores tipo buck, permitiendo la optimización del filtro LC con respecto al desempeño de la regulación en las primeras etapas de diseño, aun antes de haber finalmente elegido un método de control
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Magnetotelluric impedances of Tenerife and Balearic Islands calculated to model the Geomagnetically Induced Currents (GIC)
No full textThese datasets contain the magnetotelluric (MT) impedances calculated from the electrical resistivity models of Tenerife Island (Canary Islands) and Balearic Islands.
The Tenerife model was obtained from the 3D inversion of 148 MT sites (Piña-Varas et al. 2014). Model responses have been computed at 339 locations regularly distributed over the island, spaced about 3.3 km apart, in a period range between 0.1 and 10^5 s.
The 3-D lithospheric model for the Balearic islands was built based on the crustal and lithospheric information (Ayala et al. 2015) and using the resistivity values from Broad Band MT data in Majorca Island (Pous et al.,1995) as a constraint. The full impedances have been computed at each cell of the model for the inland locations, and along the submarine line cable locations, in both cases spaced about 2 km apart, for periods from 0.1 s to 10^5 s
Magnetotelluric impedances to build the Electrical Resistivity Model of Iberian Lithosphere (ERMIL1.0)
No full textThis dataset contains the magnetotelluric impedance used to build the Electrical Resistivity Model of Iberian Lithosphere (ERMIL) and obtained from the long period magnetotelluric surveys acquired during the last thirty years in the Iberian Peninsula
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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