Bessel and Struve Related Integrals

Analytic expressions for integrals which arise in a theory of atomic structure due to Schwinger and Englert are evaluated in terms of Bessel and Struve functionsComment: 10 page

Nonlinear buckling and folding analysis of a storable tubular ultrathin boom for nanosatellites

In this work we investigated the stability behavior and the folding capability of an ultrathin tubular composite boom with C-cross section to be used in nanosatellites applications. A nonlinear buckling analysis was performed using the Riks method, adopting a perturbed finite element model to study the influence of the unavoidable geometrical variations of the boom thickness, arising from the composite manufacturing processes, on the stability behavior of the tubular structure. The effect of several levels of geometrical imperfection on the buckling behavior was analyzed. The minimum coil radius that can be used for a safe storage the boom was determined by quasi-static explicit analysis. The boom folding process was considered as formed by two sequential steps, the flattening and the coiling. The stress fields associated with both steps were investigated

El funámbulo y el payaso. Notas sobre Friedrich Nietzsche y María Zambrano

El estudio toma como referencia el ensayo “El payaso y la filosofía” para establecer una comparación entre Zambrano y Nietzsche sobre el tema de la risa. Cotejando las metáforas del payaso y la del funámbulo en las cuales ambos autores resumen respectivamente las características del filósofo, se evidencian las similitudes y las distancias entre ellos.This study refers to Zambrano’s essay “El payaso y la filosofía” in order to compare Zambrano’s and Nietzsche’s philosophical view on the laugh. By comparing the metaphors of the clown and of the acrobat by which each author resumes the philosopher’s traits, it shows their similarities and differences

Christine de Pizan : ¿una feminista ante litteram?

En diálogo con la bibliografía crítica existente sobre Christine de Pizan y mediante una lectura atenta de La cité des dames, este artículo aboga por la consideración de esta autora como precursora feminista, subrayando el valor político de la querelle des femmes, la incipiente teoría feminista contenida en La cité des dames y la actualidad de muchos de sus elementos, como la conciencia del carácter construido del género o la concepción de lo femenino como proyección masculina

Motion Control of the Hybrid Wheeled-Legged Quadruped Robot Centauro

Emerging applications will demand robots to deal with a complex environment, which lacks the structure and predictability of the industrial workspace. Complex scenarios will require robot complexity to increase as well, as compared to classical topologies such as fixed-base manipulators, wheeled mobile platforms, tracked vehicles, and their combinations. Legged robots, such as humanoids and quadrupeds, promise to provide platforms which are flexible enough to handle real world scenarios; however, the improved flexibility comes at the cost of way higher control complexity. As a trade-off, hybrid wheeled-legged robots have been proposed, resulting in the mitigation of control complexity whenever the ground surface is suitable for driving. Following this idea, a new hybrid robot called Centauro has been developed inside the Humanoid and Human Centered Mechatronics lab at Istituto Italiano di Tecnologia (IIT). Centauro is a wheeled-legged quadruped with a humanoid bi-manual upper-body. Differently from other platform of similar concept, Centauro employs customized actuation units, which provide high torque outputs, moderately fast motions, and the possibility to control the exerted torque. Moreover, with more than forty motors moving its limbs, Centauro is a very redundant platform, with the potential to execute many different tasks at the same time. This thesis deals with the design and development of a software architecture, and a control system, tailored to such a robot; both wheeled and legged locomotion strategies have been studied, as well as prioritized, whole-body and interaction controllers exploiting the robot torque control capabilities, and capable to handle the system redundancy. A novel software architecture, made of (i) a real-time robotic middleware, and (ii) a framework for online, prioritized Cartesian controller, forms the basis of the entire work

Polynomials Associated with the Higher Derivatives of the Airy Functions Ai(z) and Ai'(z)

The Airy function Ai(z) and its derivative Ai'(z) occur in a large number of applications in Chemistry and Physics. As a result, there is a continuing interest in the properties of these functions. Recently, there has been interest in obtaining general expressions for the higher derivatives of these functions. In this work, general expressions for the polynomials which are contained in these derivatives are given in terms of the partial Bell polynomials