Exercise sheet 3 pdf

Exercises and solutions in PDF

Absence of Klein's paradox for massive spinless bosons coupled by a nonminimal vector interaction

A few properties of the nonminimal vector interaction in the Duffin-Kemmer-Petiau theory in the scalar sector are revised. In particular, it is shown that the nonminimal vector interaction has been erroneously applied to the description of elastic meson-nucleus scatterings and that the space component of the nonminimal vector interaction plays a peremptory role for the confinement of bosons whereas its time component contributes to the leakage. Scattering in a square step potential is used to show that Klein's paradox does not manifest in the case of a nonminimal vector coupling. Copyright © owned by the author(s) under the terms of the Creative Commons Attribution- NonCommercial-ShareAlike Licence.

3-D Space Vector PWM implementation for Four-Leg Voltage Source Inverter

The Space Vector PWM implementation and operation for a Four-leg Voltage Source Inverter (VSI) is detailed and discussed in this paper. Although less common, four-leg VSIs are a viable solution for situations where neutral connection is necessary, including Active Power Filter applications. This topology presents advantages regarding the VSI DC link and capacitance, which make it useful for high power devices. Theory, implementation and simulations are also discussed in this paper. © 2011 IEEE.

Tri-state Space Vector Modulation for Three-phase integrated inverters

The aim of this work is to present a modified Space Vector Modulation (SVM) suitable for Tri-state Three-phase inverters. A standard SVM algorithm and the Tri-state PWM (Pulse Width Modulation) are presented and their concept are mixed into the novel SVM. The proposed SVM is applied to a three-phase tri-state integrated Boost inverter, intended to Photovoltaic Energy Applications. The main features for this novel SVM are validated through simulations and also by experimental tests. The obtained results prove the feasibility of the proposal. © 2011 IEEE.

Three-phase tri-state integrated boost inverter with special space vector and dq0 control

This paper presents a three-phase integrated inverter suitable for stand-alone and grid-connected applications. Furthermore, the utilization of the special features of the tri-state coupled with the new space vector modulation allows the converter to present an attractive degree of freedom for the designing of the controllers. Additionally, the control is derived through dq0 transformation, all the system is described and interesting simulation results are available to confirm the proposal. © 2012 IEEE.

Improving image classification through descriptor combination

The efficiency in image classification tasks can be improved using combined information provided by several sources, such as shape, color, and texture visual properties. Although many works proposed to combine different feature vectors, we model the descriptor combination as an optimization problem to be addressed by evolutionary-based techniques, which compute distances between samples that maximize their separability in the feature space. The robustness of the proposed technique is assessed by the Optimum-Path Forest classifier. Experiments showed that the proposed methodology can outperform individual information provided by single descriptors in well-known public datasets. © 2012 IEEE.

General exercises ... June, 1893. Together with list of officers, and members, programme and rules.

Half-title (not included in pagination) : Report of the proceedings ... I. General exercises, etc. II. The public treatment of pauperism.

Codifferentiable Mappings with Applications to Vector Optimality

AMS subject classification: Primary 49J52; secondary: 26A27, 90C48, 47N10.

Orbital and strongly orbital spaces

We say that a (countably dimensional) topological vector space X is orbital if there is T∈L(X) and a vector x∈X such that X is the linear span of the orbit {Tnx:n=0,1,…}. We say that X is strongly orbital if, additionally, x can be chosen to be a hypercyclic vector for T. Of course, X can be orbital only if the algebraic dimension of X is finite or infinite countable. We characterize orbital and strongly orbital metrizable locally convex spaces. We also show that every countably dimensional metrizable locally convex space X does not have the invariant subset property. That is, there is T∈L(X) such that every non-zero x∈X is a hypercyclic vector for T. Finally, assuming the Continuum Hypothesis, we construct a complete strongly orbital locally convex space.

As a byproduct of our constructions, we determine the number of isomorphism classes in the set of dense countably dimensional subspaces of any given separable infinite dimensional Fréchet space X. For instance, in X=ℓ2×ω, there are exactly 3 pairwise non-isomorphic (as topological vector spaces) dense countably dimensional subspaces.

Contribuições da praxologia motriz para a educação fisica escolar : ensino fundamental

Universidade Estadual de Campinas . Faculdade de Educação Física

The norm of the K- Th derivative of the X-symmetric power of an operator

In this paper, the exact value for the norm of directional derivatives, of all orders, for symmetric tensor powers of operators on finite dimensional vector spaces is presented. Using this result, an upper bound for the norm of all directional derivatives of immanants is obtained.

A compositional data analysis package for R providing multiple approaches

”compositions” is a new R-package for the analysis of compositional and positive data.It contains four classes corresponding to the four different types of compositional andpositive geometry (including the Aitchison geometry). It provides means for computation,plotting and high-level multivariate statistical analysis in all four geometries.These geometries are treated in an fully analogous way, based on the principle of workingin coordinates, and the object-oriented programming paradigm of R. In this way,called functions automatically select the most appropriate type of analysis as a functionof the geometry. The graphical capabilities include ternary diagrams and tetrahedrons,various compositional plots (boxplots, barplots, piecharts) and extensive graphical toolsfor principal components. Afterwards, ortion and proportion lines, straight lines andellipses in all geometries can be added to plots. The package is accompanied by ahands-on-introduction, documentation for every function, demos of the graphical capabilitiesand plenty of usage examples. It allows direct and parallel computation inall four vector spaces and provides the beginner with a copy-and-paste style of dataanalysis, while letting advanced users keep the functionality and customizability theydemand of R, as well as all necessary tools to add own analysis routines. A completeexample is included in the appendix

Disseny d’un muntatge experimental per les practiques de Resistència de materials

Degut a l’augment del nombre de classes i d’alumnes en l’Àrea de Mecànica de MedisContinus i Teoria d’Estructures (MMCTE), s’ha fet necessari la reestructuració i ocupació denous espais per la realització de les pràctiques de Resistència de materials.Per tal de realitzar les pràctiques al nou laboratori de Resistència de materials, calredissenyar les pràctiques referents a Allargaments longitudinals en bigues sotmeses acompressió i tracció simple i la referent a la Deformada d’una biga biarticulada amb voladís.El disseny de les noves pràctiques ha de complir les condicions exigides pel client. A més,els muntatges de cada pràctica han d’anar muntats sobre un pòrtic adquirit recientment perl’Àrea de Mecànica de Medis Continus i Teoria d’Estructures (MMCTE) que actuaran debancada. La pràctica relacionada amb Allargaments longitudinals en barres sotmeses a compressió itracció simple consta d’un muntatge experimental (Muntatge 1) i un guió de pràctiques perl’alumnat i professorat docent La pràctica relacionada amb la Deformada d’una biga biarticulada amb voladís consta d’unmuntatge experimental (Muntatge 2) i un guió de pràctiques per l’alumnat i professoratdocent. Les dos pràctiques permeten comparar els valors obtinguts experimentalment de cadamuntatge amb uns resultats teòrics i d’aquesta manera validar l’èxit de cada muntatge

De les dades composicionals a una geometria euclidiana sobre el símplex

La reflexió sobre la naturalesa de les dades composicionals i sobre la metodologia estadística específica per a la seva anàlisi condueix a la construcció de l'espai de les composicions i a la seva estructuració com un espai vectorial euclidià, del qual el símplex n'és l'espai suport. S'il·lustren sobre el diagrama ternari alguns dels elements més característics d'aquesta geometria