850 research outputs found
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
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
Una contribución al registrado articulado: aplicación a la determinación de la maduración ósea mediante análisis de imágenes radiográficas
Este trabajo se plantea de un modo inédito de registrado elástico de imágenes médicas llamado “registrado articulado”. Está basado en un modelo anatómico formado por puntos de control anatómicos conectados entre sí en el que cada hueso es registrado de forma afín y los tejidos blandos son registrados de forma elástica, manteniendo las estructuras óseas largas rectas mientras que la transformación a lo largo de toda la imagen es continua y suave. Se aplica el método articulado en el registrado de radiografías de la mano superando a otros métodos alternativos. Además hemos generalizado al marco de registrado poliafín Log-Euclídeo de forma que permita estructuras articuladas.
Se propone también una metodología inédita basada en registrado de imagen para determinar de forma automática la edad ósea siguiendo el método TW3. Este método realiza el registrado de la radiografía de la mano como un paso previo. Proponemos dos clasificadores diferentes y comparamos sus resultados con los diagnósticos realizados por dos especialistas pediátricos; la metodología seguida nos lleva a la conclusión de que nuestro método automático obtiene resultados comparables a los diagnósticos inter-observador.Departamento de Teoría de la Señal y Comunicaciones e Ingenieria Telemátic
¿Te gusta conducir? Una mirada crítica desde la publicidad de coches y su retórica medioambiental
Sustainable development, as well as other narratives within the framework of environmental conservation, is often used as an advertising resource to improve a brand image. In this paper, a teaching proposal based on a critical analysis of the discourse of a set of television commercials is presented. Specific attention is given to the car industry, due to its huge environmental implications and its impact in mass media and popular culture. This study highlights that persuasive discourses around automobile still persist, which are more emotional than rational, as a way to elude the true debates about today's social and environmental challenges
“Corkwood”, un nuevo material natural, renovable y sostenible. Una materia prima única para comunicar naturaleza y sostenibilidad
It is scientifically proven that exposure to noise has negative effects on comfort and on the people’s health. Also, “Spain is one of the noisiest countries in the world.” Therefore, it is necessary to have a good insulation and acoustic conditioning to guarantee the well-being and health of people. This research is focused on developing some material with sound absorbing properties without complex machining systems and with a beautiful design. In addition, these insulation qualities allow energy savings in homes, which adds more good properties at the place.Está científicamente probado que la exposición al ruido tiene efectos negativos no solo en el confort sino también en la salud de las personas. En este sentido, “España se sitúa entre los países más ruidosos del mundo”. Por ello, es necesario disponer de un buen aislamiento y acondicionamiento acústico para garantizar el bienestar y la salud de las personas. Esta investigación está enfocada a desarrollar un material con propiedades fonoabsorbentes sin precisar complejos sistemas de mecanizado ni renunciar al diseño. Además estas cualidades de aislamiento permiten un ahorro energético en las viviendas lo que le aporta un valor añadido a la estética del lugar
Redescubrimiento del liquen lobaria pulmonaria, aparentemente extinto en la Comunidad Valenciana
El liquen Lobaria pulmonaria, aparentemente extinto en la Comunidad Valenciana, ha sido reencontrado en estado silvestre en el norte de Castellón. El dilatado periodo transcurrido desde que fue citado por Cavanilles, en el siglo XVIII, y por J. Vilanova, en el XIX, confiere una importancia adicional a este descubrimiento.The lichen Lobaria pulmonaria, becoming considered extinct in the Valencian Community (E Spain), has been newly found in the north of Castellón. The large period since it was cited here by Cavanilles, in the 18th century, and by J. Vilanova, in the 19th century confers additional importance to this discovery
Adaptación de la Escala de Creencias sobre el Bienestar a la población española
The study of happiness and well-being is receiving increased attention in different fields. Recent research into well-being has focused on delving deeper into the individual’s conception about the experience of well-being. McMahan and Estes (2011a) created a scale that assesses lay conceptions of well-being (BWBS) based on four dimensions: the experience of pleasure, avoidance of negative experience, self-development and contribution to others. The goal of this study was to adapt this scale, the Beliefs about Well-Being Scale, to the Spanish population. The sample consisted of 1,024 participants from the general population ranging in age interval from 17 to 87 years old. The confirmatory factorial analysis results in a structure of four dimensions, similar to the original scale, although in the adaptation of the scale the items decrease from 16 to 12. The results of the reliability analysis reveal indexes similar to those of the original scale. These results confirm the validity of Beliefs about Well-Being Scale with general population in a cultural context different from the original study. This will allow cross-cultural studies to analyze the influence of culture in the perception of well-being.El estudio de la felicidad y el bienestar está recibiendo cada vez más atención en diferentes campos. Las investigaciones recientes sobre el bienestar se han centrado en profundizar en la concepción del individuo sobre la experiencia del bienestar. McMahan y Estes (2011a) crearon una escala que evalúa las concepciones legas del bienestar en base a cuatro dimensiones: la experiencia de placer, la evitación de la experiencia negativa, el autodesarrollo y la contribución a los demás. El objetivo de este estudio fue adaptar esta escala, Beliefs about Well-Being Scale (BWBS), a la población española. La muestra estuvo formada por 1.024 participantes de la población general con un intervalo de edad entre 17 y 87 años. El análisis factorial confirmatorio da como resultado una estructura de cuatro dimensiones, similar a la escala original, aunque en la adaptación de la escala los ítems disminuyen de 16 a 12. Los resultados del análisis de fiabilidad revelan índices similares a los de la escala original. Estos resultados confirman la validez de la Escala de Creencias sobre el Bienestar con población general en un contexto cultural diferente al del estudio original. Esto permitirá realizar estudios transculturales para analizar la influencia de la cultura en la percepción del bienesta
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
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