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Title: Evolution in a changing environment
Authors: Baronchelli, Andrea; Chater, Nick; Christiansen, M.H.; Pastor Satorras, Romualdo
Abstract: We propose a simple model for genetic adaptation to a changing environment, describing a fitness landscape characterized by two maxima. One is associated with “specialist” individuals that are adapted to the environment; this maximum moves over time as the environment changes. The other maximum is static, and represents “generalist” individuals not affected by environmental changes. The rest of the landscape is occupied by “maladapted” individuals. Our analysis considers the evolution of these three subpopulations. Our main result is that, in presence of a sufficiently stable environmental feature, as in the case of an unchanging aspect of a physical habitat, specialists can dominate the population. By contrast, rapidly changing environmental features, such as language or cultural habits, are a moving target for the genes; here, generalists dominate, because the best evolutionary strategy is to adopt neutral alleles not specialized for any specific environment. The model we propose is based on simple assumptions about evolutionary dynamics and describes all possible scenarios in a non-trivial phase diagram. The approach provides a general framework to address such fundamental issues as the Baldwin effect, the biological basis for language, or the ecological consequences of a rapid climate change.
Title: A new approach to DInSAR pixel selection with spectral correlation along time between Sublooks
Authors: Iglesias González, Rubén; Monells Miralles, Daniel; Centolanza, Giuseppe; Mallorquí Franquet, Jordi Joan
Abstract: This paper presents a full resolution pixel selection method, alternative to the traditional ones, which is based on
the study of the spectral correlation coefficient along time among different Sublooks of the image spectrum. This
pixel selection criterion has been developed from the concept of the so-called Coherent Scatters (CSs), which
are characterized by a deterministic point-like scattering behaviour in each single acquisition, but now including
its temporal stability. The proposed method presents the advantage that it does not require any radiometric cali-
bration of the data as it only uses the spectral propertie
s of a point-scatter but not
relying on its amplitude.
Title: What determines the wavelength of self-organized shoreline sand waves?
Authors: Falqués Serra, Albert; Van den Berg, Niels; Ribas Prats, Francesca; Caballeria, M
Abstract: Shoreline undulations extending into the bathymetric contours with a length scale larger than that of the rhythmic surf zone bars are referred to as shoreline sand waves. Many observed undulations along sandy coasts display a wavelength in the order 1-7 km. Several models that are based on the hypothesis that sand waves emerge from a morphodynamic instability in case of very oblique wave incidence predict this range of wavelengths. Here we investigate the physical reasons for the wavelength selection and the main parametric trends of the wavelength in case of sand waves arising from such instability. It is shown that the existence of a minimum wavelength depends on an interplay between three factors affecting littoral drift: (A) the angle of wave fronts relative to local shoreline, which tends to cause maximum transport at the downdrift flank of the sand wave, (B) the refractive energy spreading which tends to cause maximum transport at the updrift flank and (C) wave focusing (de-focusing) by the capes (bays), which tends to cause maximum transport at the crest or slightly downdrift of it. Processes A and C cause decay of the sand waves while process B causes their growth. For low incidence angles, B is very weak so that a rectilinear shoreline is stable. For large angles and long sand waves, B is dominant and causes the growth of sand waves. For large angles and short sand waves C is dominant and the sand waves decay. Thus, wavelength selection depends on process C, which essentially depends on shoreline curvature. The growth rate of very long sand waves is weak because the alongshore gradients in sediment transport decrease with the wavelength. This is why there is an optimum or dominant wavelength. It is found that sand wave wavelength scales with ?0/? where ?0 is the water wave wavelength in deep water and ? is the mean bed slope from shore to the wave base.
Title: Intertidal finger bars at El Puntal spit, bay of Santander, Spain
Authors: Garnier, Roland; Medina, Raúl; Pellón, Erica; Falqués Serra, Albert; Turki, Imen
Abstract: We indentify the presence of an intertidal finger bar system in the swell-protected beaches of El Puntal Spit (Bay of Santander, Spain). The Horus video monitoring system allows us to perform a 2 year survey (June 2008- June 2010). We found that the bar system persists during the survey period with a wavelength of about 25 m and an oblique orientation with respect to the shore. Moreover, the analysis of the position of a particular bar (Bar 10) shows a
movement characterized by a net migration to the west and a faster oscillation to the east or the west. Preliminary climate data analysis and morphological model results show that tide seems to be a forcing in the motion of the bars but also wind and waves generated by the wind probably affects the bar dynamics.
Title: Halogen-free flame retardant polyolefin foams
Authors: Redondo Realinho, Vera Cristina de; Sousa Pais Antunes, Marcelo de; Santana Pérez, Orlando Onofre; Velasco Perero, José Ignacio
Abstract: The present work deals with the preparation and characterizacion of an improved fire-resistant ethylene-acrylate foamed material containing calcium carbonate and a silicon elastomer. This grade, usually employed on the cable industry sector, was modified two differents synergistic FR systems : silica/zinc borate (S/ZB) and montmorillonite/graphite nanoplatelets(N). The different formulations were prepared by melt-blending and the foams by a compression-molding foaming process using Azodicarbonamide as chemical blowing agent. Thermal stability and fire behaviour, of both solid and foamed materials were characterized by means of thermogravimetric and cone calorimetric techniques, respectively.
Title: Gene expression data classification combining hierarchical representation and efficient feature selection
Authors: Bosio, Mattia; Bellot Pujalte, Pau; Salembier Clairon, Philippe Jean; Oliveras Vergés, Albert
Abstract: A general framework for microarray data classification is proposed in this paper. It pro-
duces precise and reliable classifiers through a two-step approach. At first, the original
feature set is enhanced by a new set of features called metagenes. These new features
are obtained through a hierarchical clustering process on the original data. Two different
metagene generation rules have been analyzed, called Treelets clustering and Euclidean
clustering. Metagenes creation is attractive for several reasons: first, they can improve
the classification since they broaden the available feature space and capture the com-
mon behavior of similar genes reducing the residual measurement noise. Furthermore,
by analyzing some of the chosen metagenes for classification with gene set enrichment
analysis algorithms, it is shown how metagenes can summarize the behavior of func-
tionally related probe sets. Additionally, metagenes can point out, still undocumented,
highly discriminant probe sets numerically related to other probes endowed with prior
biological information in order to contribute to the knowledge discovery process.
The second step of the framework is the feature selection which applies the Improved
Sequential Floating Forward Selection algorithm (IFFS) to properly choose a subset from
the available feature set for classification composed of genes and metagenes. Considering
the microarray sample scarcity problem, besides the classical error rate, a reliability
measure is introduced to improve the feature selection process. Different scoring schemes
are studied to choose the best one using both error rate and reliability. The Linear
Discriminant Analysis classifier (LDA) has been used throughout this work, due to its
good characteristics, but the proposed framework can be used with almost any classifier.
The potential of the proposed framework has been evaluated analyzing all the publicly
available datasets offered by the Micro Array Quality Control Study, phase II (MAQC).
The comparative results showed that the proposed framework can compete with a wide
variety of state of the art alternatives and it can obtain the best mean performance
if a particular setup is chosen. A Monte Carlo simulation confirmed that the proposed
framework obtains stable and repeatable results.
Title: Application of predictive control strategies to the management of complex networks in the urban water cycle
Authors: Ocampo-Martínez, Carlos; Puig Cayuela, Vicenç; Cembrano Gennari, Gabriela; Quevedo Casín, Joseba Jokin
Abstract: The management of the urban water cycle (UWC) is a subject of increasing interest because of its social, economic, and environmental impact. The most important issues include the sustainable use of limited resources and the reliability of service to consumers with adequate quality and pressure levels, as well as the urban drainage management to prevent flooding and polluting discharges to the environment.
Title: Adaptive sampling for fast sparsity pattern recovery
Authors: Ramírez Javega, Francisco; Matas Navarro, David; Lamarca Orozco, M. Meritxell
Abstract: In this paper we propose a low complexity adaptive algorithm
for lossless compressive sampling and reconstruction of
sparse signals. Consider a sparse non-negative real signal x
containing only ???? << ???? non-zero values. The sampling process
obtains ???? measurements by a linear projection y = Ax
and, in order to minimize the complexity, we quantize them
to binary values. We also define the measurement matrix A
to be binary and sparse, enabling the use of a simple message
passing algorithm over a graph. We show how to adaptively
construct this matrix in a multi-stage process that sequentially
reduces the search space until the sparsity pattern is
perfectly recovered. As verified by simulation results, the
process requires ????(????) operations and ????(???? log(????/????)) samples
Title: Binary graphs and message passing strategies for compressed sensing in the noiseless setting
Authors: Ramírez Javega, Francisco; Lamarca Orozco, M. Meritxell; Villares Piera, Nemesio J.
Abstract: We propose a scheme for Compressed Sensing in the noiseless setting that reconstructs the original signal operating on a binary graph where the samples are obtained sequentially. The proposed scheme has an affordable computational complexity and a large performance enhancement with respect to similar schemes in the literature, thanks to the proposed measurement matrix structure and enhanced decoding based on a message passing algorithm.
Title: On the design of UAS horizontal separation maneuvers
Authors: Pastor Llorens, Enric; Pérez Batlle, Marcos; Royo Chic, Pablo; Cuadrado Santolaria, Raúl; Barrado Muxí, Cristina; Prats Menéndez, Xavier
Abstract: This paper studies the separation maneuvers that
an Unmanned Air System (UAS) may execute to avoid breaching
the separation safety margins imposed in each type of airspace,
namely 3 NM, 5 NM, and 10 NM. The UAS was assumed
under the control of its Pilot in Command, with available
information about its surrounding traffic through ADS-B or
ADS-C, and most likely under the supervision of an ATCo.
A number of UAS separation maneuvers have been identified
that may guarantee the desired levels of separation if executed
with the right parameters and enough anticipation. This paper
focuses on identification of the most suitable maneuver for
any separation conflict geometry and performance envelop. The
conflict geometry is modeled to take into account the speed of
both vehicles (the UAS and the intruder), the conflict angle, the
turning limitations of the UAS, the reaction time of the pilot, and
the communication latency.
Title: A taxonomy of UAS separation maneuvers and their automated execution
Authors: Pérez Batlle, Marcos; Pastor Llorens, Enric; Royo Chic, Pablo; Prats Menéndez, Xavier; Barrado Muxí, Cristina
Abstract: This paper proposes to create a taxonomy of separation conflicts between Unmanned Aerial Systems (UAS) and intruding aircrafts to facilitate its insertion in non-segregated airspace. The classification is created according to the relative speeds, angular geometry, initial intent, etc. A catalog of separation maneuvers that best fit each scenario is introduced and evaluated through a real-time simulation environment. This advisory mechanism will benefit both the UAS pilot and the ATCo in order to negotiate the best suited separation maneuver. Eventually, the same strategy can be employed as an autonomous separation system on-board a UAS that suffers a lost-link contingency, alleviating its negative impact in the airspace.
Title: Existing relevant indicators sets in the Basque Country
Authors: Burns, Malcolm
Abstract: EXISTING RELEVANT INDICATORS SETS IN THE BASQUE COUNTRY
Title: Valoración de los terrenos expropiados en el Camino Alto Cocorón de la ciudad de Huesca
Authors: Pérez Lamas, Carlos
Title: La persona projectual al claustre de Pedralbes
Authors: Lloveras Montserrat, Joaquín
Title: Construcción de modelos de ciudad
Authors: Marambio Castillo, Alejandro Esteban; García Almirall, M. Pilar; Lucena Salas, Jennifer
Title: Optical subsystems for next generation access networks
Authors: Lázaro Villa, José Antonio; Polo Querol, Víctor; Schrenk, Bernhard; Bonada Bo, Francesc; Cano Valadéz, Iván Nicolás; López, E.T.; Kazmierski, Christophe; de Valicourt, Guilhem; Brenot, Romain; Bauwelinck, Johan; Xing-Zhi, Qiu; Ossieur, P.; Forzati, Marco; Rigole, Jean-Pierre; Monroy, I.T; Tangdiongga, E.; Morant, Maryland; Nicolau, L.; Teixeira, A.L.; Erasme, D.; Klonidis, Dimitrios; Tomkos, Ioannis; Prat Gomà, Josep Joan; Kouloumentas,, Christos; Avramopoulos, Hércules
Abstract: Recent optical technologies are providing higher flexibility to next generation access
networks: on the one hand, providing progressive FTTx and specifically FTTH deployment,
progressively shortening the copper access network; on the other hand, also opening fixed-mobile
convergence solutions in next generation PON architectures. It is provided an overview of the
optical subsystems developed for the implementation of the proposed NG-Access Networks.
Title: Regulació de les actuacions urbanístiques aïllades o puntuals
Authors: Pérez Lamas, Carlos
Title: Smart - STATCOM control strategy implementation in wind power plants
Authors: Sintamarean, Craiun; Cantarellas, A.; Miranda, Hernan; Rodríguez Cortés, Pedro; Teodorescu, Remus
Abstract: High penetration of wind energy into the grid may introduce stability and power quality problems due to the fluctuating nature of the wind and the increasing complexity of the power system. By implementing advanced functionalities in power converters, it is possible to improve the performance of the wind farm and also to provide grid support, as it is required by the grid codes. One of the main compliance difficulties that can be found in such power plants are related to reactive power compensation and to keep the harmonics content between the allowed limits, even if the power of the WPP converters is increasing. This paper deals with an advanced control strategy design of a three-level converter performing STATCOM and Active Filter functionalities. The proposed system is called Smart-STATCOM since it has the capability of self-controlling reactive power and harmonic voltages at the same time. Therefore, deciding the amount of non-active currents (fundamental, 5th and 7th harmonics) to be injected depending on the PCC voltage quality. Experimental results of the proposed control strategy are analyzed in order to validate the performance of the entire system. Keywords- STATCOM, Active Filter, Power Quality
Title: Proyecto de urbanización o bien Proyecto de obras ordinarias
Authors: Pérez Lamas, Carlos
Title: Immigració, cohesió social i convivéncia al espai públic
Authors: García Almirall, M. Pilar