Potencialidad de la modelización state-space y el filtro de Kalman para el anàlisis regional : una aplicación para el índice de actividad industrial

El déficit existente a nuestro país con respecto a la disponibilidad de indicadores cuantitativos con los que llevar a término un análisis coyuntural de la actividad industrial regional ha abierto un debate centrado en el estudio de cuál es la metodología más adecuada para elaborar indicadores de estas características. Dentro de este marco, en este trabajo se presentan las principales conclusiones obtenidas en anteriores estudios (Clar, et. al., 1997a, 1997b y 1998) sobre la idoneidad de extender las metodologías que actualmente se están aplicando a las regiones españolas para elaborar indicadores de la actividad industrial mediante métodos indirectos. Estas conclusiones llevan a plantear una estrategia distinta a las que actualmente se vienen aplicando. En concreto, se propone (siguiendo a Israilevich y Kuttner, 1993) un modelo de variables latentes para estimar el indicador de la producción industrial regional. Este tipo de modelo puede especificarse en términos de un modelo statespace y estimarse mediante el filtro de Kalman. Para validar la metodología propuesta se estiman unos indicadores de acuerdo con ella para tres de las cuatro regiones españolas que disponen d¿un Índice de Producción Industrial (IPI) elaborado mediante el método directo (Andalucía, Asturias y el País Vasco) y se comparan con los IPIs publicados (oficiales). Los resultados obtenidos muestran el buen comportamiento de l¿estrategia propuesta, abriendo así una línea de trabajo con la que subsanar el déficit al que se hacía referencia anteriormente

SL(3,C) elementary instanton configurations

Several SL(3,C) self-dual instanton solutions of the Yang-Mills equations are presented which have very striking properties. While one of them is regular and SU(3) inside (outside) a sphere of arbitrarily large (small) radius, another one has all the characteristics of a meron solution (in particular its topological charge is concentrated at one point) although its Pontryagin number equals one. Their continuation to Minkowski space is also studied.

Families of periodic orbits for the spatial isosceles 3-body problem

We study the families of periodic orbits of the spatial isosceles 3-body problem (for small enough values of the mass lying on the symmetry axis) coming via the analytic continuation method from periodic orbits of the circular Sitnikov problem. Using the first integral of the angular momentum, we reduce the dimension of the phase space of the problem by two units. Since periodic orbits of the reduced isosceles problem generate invariant two-dimensional tori of the nonreduced problem, the analytic continuation of periodic orbits of the (reduced) circular Sitnikov problem at this level becomes the continuation of invariant two-dimensional tori from the circular Sitnikov problem to the nonreduced isosceles problem, each one filled with periodic or quasi-periodic orbits. These tori are not KAM tori but just isotropic, since we are dealing with a three-degrees-of-freedom system. The continuation of periodic orbits is done in two different ways, the first going directly from the reduced circular Sitnikov problem to the reduced isosceles problem, and the second one using two steps: first we continue the periodic orbits from the reduced circular Sitnikov problem to the reduced elliptic Sitnikov problem, and then we continue those periodic orbits of the reduced elliptic Sitnikov problem to the reduced isosceles problem. The continuation in one or two steps produces different results. This work is merely analytic and uses the variational equations in order to apply Poincar´e’s continuation method.

Nonpoint source pollution, space, time and asymetric information - a deposit refund approach

The incorporation of space allows the establishment of a more precise relationship between a contaminating input, a contaminating byproduct and emissions that reach the final receptor. However, the presence of asymmetric information impedes the implementation of the first-best policy. As a solution to this problem a site specific deposit refund system for the contaminating input and the contaminating byproduct are proposed. Moreover, the utilization of a successive optimization technique first over space and second over time enables definition of the optimal intertemporal site specific deposit refund system

Reflexiones sobre el espacio público = Thoughts on Public Space

En este artículo planteamos una aproximación a la idea de espacio público como articulador del conjunto de acontecimientos que intervienen en la vida de las ciudades. Entendemos este fenómeno como una red poliédrica y multidimensional, cuyo estudio pasa por el análisis de diversas problemáticas: la identificación de los límites entre espacio público y esfera pública; la conformación del espacio público construido; la aproximación teórica al fenómeno desde la contemporaneidad; la dimensión social del espacio público; y finalmente la perspectiva de la gestión de las ciudades. Todas estas dimensiones expresan una mirada crítica del objeto i ponen en valor niveles de trabajo interdisciplinar y multiescala, fundamentales para entender e intervenir en el espacio público de la ciudad contemporánea.

Public Art, strategies for the regeneration of public space

This paper discusses some of the key concepts in the consideration of public art as a central element in urban regeneration processes, especially in reference to its role in the processes of citizen participation.

Reflexiones sobre el espacio público = Thoughts on Public Space

En este artículo planteamos una aproximación a la idea de espacio público como articulador del conjunto de acontecimientos que intervienen en la vida de las ciudades. Entendemos este fenómeno como una red poliédrica y multidimensional, cuyo estudio pasa por el análisis de diversas problemáticas: la identificación de los límites entre espacio público y esfera pública; la conformación del espacio público construido; la aproximación teórica al fenómeno desde la contemporaneidad; la dimensión social del espacio público; y finalmente la perspectiva de la gestión de las ciudades. Todas estas dimensiones expresan una mirada crítica del objeto i ponen en valor niveles de trabajo interdisciplinar y multiescala, fundamentales para entender e intervenir en el espacio público de la ciudad contemporánea.

Space Manifold dynamics

The term Space Manifold Dynamics (SMD) has been proposed for encompassing the various applications of Dynamical Systems methods to spacecraft mission analysis and design, ranging from the exploitation of libration orbits around the collinear Lagrangian points to the design of optimal station-keeping and eclipse avoidance manoeuvres or the determination of low energy lunar and interplanetary transfers

Space Manifold dynamics

The term Space Manifold Dynamics (SMD) has been proposed for encompassing the various applications of Dynamical Systems methods to spacecraft mission analysis and design, ranging from the exploitation of libration orbits around the collinear Lagrangian points to the design of optimal station-keeping and eclipse avoidance manoeuvres or the determination of low energy lunar and interplanetary transfers

Lattices for 3-Dimensional Fuzzy Data generated by Fuzzy Galois Connections

Vagueness and high dimensional space data are usual features of current data. The paper is an approach to identify conceptual structures among fuzzy three dimensional data sets in order to get conceptual hierarchy. We propose a fuzzy extension of the Galois connections that allows to demonstrate an isomorphism theorem between fuzzy sets closures which is the basis for generating lattices ordered-sets

Definition of linear color models in the RGB vector color space to detect red peaches in orchard images taken under natural illumination

This work proposes the detection of red peaches in orchard images based on the definition of different linear color models in the RGB vector color space. The classification and segmentation of the pixels of the image is then performed by comparing the color distance from each pixel to the different previously defined linear color models. The methodology proposed has been tested with images obtained in a real orchard under natural light. The peach variety in the orchard was the paraguayo (Prunus persica var. platycarpa) peach with red skin. The segmentation results showed that the area of the red peaches in the images was detected with an average error of 11.6%; 19.7% in the case of bright illumination; 8.2% in the case of low illumination; 8.6% for occlusion up to 33%; 12.2% in the case of occlusion between 34 and 66%; and 23% for occlusion above 66%. Finally, a methodology was proposed to estimate the diameter of the fruits based on an ellipsoidal fitting. A first diameter was obtained by using all the contour pixels and a second diameter was obtained by rejecting some pixels of the contour. This approach enables a rough estimate of the fruit occlusion percentage range by comparing the two diameter estimates.

Supergravity models of (3+1)-dimensional QCD

The most general black M5-brane solution of eleven-dimensional supergravity (with a flat R4 spacetime in the brane and a regular horizon) is characterized by charge, mass and two angular momenta. We use this metric to construct general dual models of large-N QCD (at strong coupling) that depend on two free parameters. The mass spectrum of scalar particles is determined analytically (in the WKB approximation) and numerically in the whole two-dimensional parameter space. We compare the mass spectrum with analogous results from lattice calculations, and find that the supergravity predictions are close to the lattice results everywhere on the two dimensional parameter space except along a special line. We also examine the mass spectrum of the supergravity Kaluza-Klein (KK) modes and find that the KK modes along the compact D-brane coordinate decouple from the spectrum for large angular momenta. There are however KK modes charged under a U(1)×U(1) global symmetry which do not decouple anywhere on the parameter space. General formulas for the string tension and action are also given.

From room for books to room for users: an old infantry barrack as an answer to the lack of space

At the beginning of the 21st century, some Catalan university libraries detected a need stemming from the lack of space and the reconversion of physical libraries within the new European educational panorama. With the same cooperative spirit that characterized previous CBUC (Consortium of Academic Libraries of Catalonia) programs and services, the Consortium set in motion a project to address this need. An initial study was commissioned in 2002, and in 2003 a suitable building (old infantry barracks) was found in Lleida. The official opening took place in 2008. GEPA (Guaranteed Space for the Preservation of Access) facility is a cooperative repository, whose objectives are to store and preserve low use documents, ensuring their future access when needed, to convert room for books into room for library users, and doing it saving both space and money. The paper presents a brief historical introduction about the physical management of collections in libraries, and a short overview about high density library repositories all over the world, as an answer to the pressing problem of lack of spaces. The main goals of the communication are to comment the architectural project and its librarian issues, and to show how the GEPA facility allowed to change the spaces in university libraries in Catalonia. On the one hand, the paper deals with the selection of an old building to be renovated, the determination of the librarian needs, the compact shelving system chosen to store the documents in the building, the relation between physical space and information management, and the logistics involved in the load of low use documents from the libraries into the facility. On the other hand, we will show some examples of physical changes in Catalan libraries after large loads of documents to GEPA.

Extending body space in immersive virtual reality: a very long arm illusion

Recent studies have shown that a fake body part can be incorporated into human body representation through synchronous multisensory stimulation on the fake and corresponding real body part- the most famous example being the Rubber Hand Illusion. However, the extent to which gross asymmetries in the fake body can be assimilated remains unknown. Participants experienced, through a head-tracked stereo head-mounted display a virtual body coincident with their real body. There were 5 conditions in a between-groups experiment, with 10 participants per condition. In all conditions there was visuo-motor congruence between the real and virtual dominant arm. In an Incongruent condition (I), where the virtual arm length was equal to the real length, there was visuo-tactile incongruence. In four Congruent conditions there was visuo-tactile congruence, but the virtual arm lengths were either equal to (C1), double (C2), triple (C3) or quadruple (C4) the real ones. Questionnaire scores and defensive withdrawal movements in response to a threat showed that the overall level of ownership was high in both C1 and I, and there was no significant difference between these conditions. Additionally, participants experienced ownership over the virtual arm up to three times the length of the real one, and less strongly at four times the length. The illusion did decline, however, with the length of the virtual arm. In the C2-C4 conditions although a measure of proprioceptive drift positively correlated with virtual arm length, there was no correlation between the drift and ownership of the virtual arm, suggesting different underlying mechanisms between ownership and drift. Overall, these findings extend and enrich previous results that multisensory and sensorimotor information can reconstruct our perception of the body shape, size and symmetry even when this is not consistent with normal body proportions.