On the relationship between bilevel decomposition algorithms and direct interior-point methods

Engineers have been using bilevel decomposition algorithms to solve certain nonconvex large-scale optimization problems arising in engineering design projects. These algorithms transform the large-scale problem into a bilevel program with one upperlevel problem (the master problem) and several lower-level problems (the subproblems). Unfortunately, there is analytical and numerical evidence that some of these commonly used bilevel decomposition algorithms may fail to converge even when the starting point is very close to the minimizer. In this paper, we establish a relationship between a particular bilevel decomposition algorithm, which only performs one iteration of an interior-point method when solving the subproblems, and a direct interior-point method, which solves the problem in its original (integrated) form. Using this relationship, we formally prove that the bilevel decomposition algorithm converges locally at a superlinear rate. The relevance of our analysis is that it bridges the gap between the incipient local convergence theory of bilevel decomposition algorithms and the mature theory of direct interior-point methods

Difusión y copia del Niño Jesús dormido sobre la cruz de Martínez Montañés en Iberoamérica

Ejemplo de las estrechas relaciones artísticas entre España y la América Virreinal a lo largo del Barroco, es la imagen del Niño Jesús dormido sobre la cruz salida del taller sevillano del escultor Juan Martínez Montañés, cuyo estudio iconográfico, difusión en América y copia en los talleres virreinales abordamos en el presente trabajo.Example of the narrow artistic relations between Spain and the Viceregal America along the Baroque, is the image of the Child Jesus slept on the cross of the Sevillian workshop of the sculptor Juan Martínez Montañés, whose iconographic study, diffusion in America and copy in the viceregal workshops we approach in the present work

Graphic study and geovisualization of the old windmills of La Mancha (Spain)

In Spain, one can find geographical diversity and unique sites of great significance and cultural heritage. Many of the nation’s treasured places, however, have deteriorated or have even disappeared. What is left, then, should be studied and documented both graphically and infographically. It is important to preserve and document Spain’s unique locations, especially those related to vernacular heritage, to transhumance and visual impact assessment in many national infrastructures projects. Windmills are important examples of agro-industrial heritage and are sometimes found in the beds of streams and rivers but can also be found high in the hills. Their presence is constant throughout the Iberian Peninsula. These mills are no longer in use due to technological advances and the emergence of new grinding systems. The aim of this study was to present a specific methodology for the documentation of windmills, to create a graphical representation using computer graphics, as well as to disseminate knowledge of this agro-industrial heritage. This research has integrated graphic materials, including freehand sketches, photographs, digital orthophotos, computer graphics and multimedia in the creation of a specific methodology based on cutting-edge technology such as a digital photogrammetric workstation (DPW), global navigation satellite systems (GNSS), computer-aided design (CAD) and computer animation

The logarithmic spiral, autoisoptic curve

In the Line of Investigation that in the department of “Technical Drawing” in the School of Agriculture Engineering of Madrid, we carry out on the study of The Technical Curves and his singularities, we demonstrate an interesting property of the Logarithmic Spiral. The demonstrated property consists of which the logarithmic spiral is a autoisoptic curve, that is to say that if from a point P anyone of the spiral tangent straight lines draw up to the previous arc, these form a constant angle α. This demonstration is novel and in addition we get to contribute a method to calculate the angle α given the equation of the spiral

Un saber menos dado: nuevos posicionamientos en el campo de la salud mental colectiva

La salud colectiva es ya un paradigma de largo recorrido en América Latina. La salud mental colectiva, por su parte, ha tenido un desarrollo relevante en algunos países latinoamericanos, e incluso ha actuado como estímulo para la reforma psiquiátrica en estos países. Sin embargo, ambas aparecen encapsuladas en un tiempo y territorio, entre otras cosas, por la hegemonía de una epistemología-mundo que, mientras ha impuesto un modelo naturalizado de verdad, ha negado la posibilidad de que otros saberes discutan sobre aquello ya ordenado (nosologías, protocolos, políticas, etc.), y menos aún sobre el propio ordenamiento. En este artículo reflexionamos sobre el poder de la etnografía, en tanto forma de conocimiento y relación social en sí misma, para ensanchar los espacios para una salud colectiva posible en un contexto donde aún es incipiente: Europa. La idea es que el punto de vista etnográfico facilita repensar lo ya dado, creando permeabilidad en las prácticas ya sedimentadas, así como nuevas ventanas de asombro.Collective health is a paradigm with a long history in Latin America. Similarly, collective mental health has had an interesting development in certain Latin American countries, even acting to stimulate psychiatric reform. However, both paradigms appear to be encapsulated in specific times and places, among other reasons because of a hegemonic global-scale epistemology that, by imposing a naturalized model of truth, denies other forms of knowledge the opportunity to question not only already-established disease categories, treatment protocols and health policies, but the established order itself. In this article, we reflect on the power of ethnography, as both a form of knowledge and a social relation in itself, to broaden the space available for a possible field of collective health in a context where it is still incipient: Europe. The ethnographic point of view allows us to rethink that which is already accepted, creating permeability in entrenched practices and opening up surprising new possibilities

Development of the instrumentation of the botafoc breakwater nº 8 caisson

Balearic Port Authority has developed an instrumentation system for the #8 caisson of the Botafoc breakwater that integrates 12 pressure sensors located at three surfaces, two in contact with the sea water and another with the bottom. This design was completed with an inertial system that measures the angular velocities and the accelerations over the three Cartesian axes. Consequently, the system measures actions (pressures) and reactions (movements and accelerations) experimented by the caisson, due to sea waves and/or other service loads. R+D department of the Port Authority and Polytechnic University of Madrid are working on two directions, the development of new theories on vertical breakwater design that go beyond Goda and Sainflou, and on the creation of a real-time critical structure alarm system, based on the instrumentation installed. This alarm system has two main parts: the instrumentation itself that collects data and processes it on real-time (the data processing compares the pressure law suffered by the caisson in every step process with the design critical state of the caisson, in this case the Goda pressure law for a 6.5 m wave), giving a security coefficient that points out the risk level on real-time; and the alarm system consisting of a monitoring panel located in the Port Control Center that shows the risk level and advises in case of an incidental evacuation of this critical portuary installation

Lambda = 3 mm line survey of nearby active galaxies

We used the IRAM 30m telescope to observe the frequency range [86-116]GHz towards the central regions of the starburst galaxies M83, M82, and NGC253, the AGNs M51, NGC1068, and NGC7469, and the ULIRGs Arp220 and Mrk231. Assuming LTE conditions, we calculated the column densities of 27 molecules and 10 isotopologues. Among others, we report the first tentative detections of CH3CHO, HNCO, and NS in M82 and, for the first time in the extragalactic medium, HC5N in NGC253. Halpha recombination lines were only found in M82 and NGC253. Vibrationally excited lines of HC3N were only detected in Arp220. CH3CCH emission is only seen in the starburst-dominated galaxies. By comparison of the fractional abundances among the galaxies, we looked for the molecules that are best suited to characterise the chemistry of starbursts, AGNs and ULIRGs, as well as the differences among galaxies within the same group.Comment: 24 pages, 6 figures, 12 tables. Accepted for publication in Astronomy and Astrophysic