La ciencia y nosotros

Science is the most refined cultural element to describe and manage the environment. It is the result of a permanent evolutionary algorithm and represents an adaptive biological advantage for the human species. Science evolves socially through physical records and information media, whose changes influence both science and society. Information professionals have been managing these physical records or knowledge containers. The technodigital revolution grows an industrialized information society where science is a productive workforce, with a neurodigital nature, and develops as a collective enterprise. Science containers are now very changeable, plural, segmented, networking, and take on a business look: they become “specific information platforms”. Information professionals’ position is rather weak, but they have the possibility to turn into information engineers, to participate in some of those platforms and to compete individually as information managers in the science arena

Testing quaternion properness: generalized likelihood ratios and locally most powerful invariants

This paper considers the problem of determining whether a quaternion random vector is proper or not, which is an important problem because the structure of the optimal linear processing depends on the specific kind of properness. In particular, we focus on the Gaussian case and consider the two main kinds of quaternion properness, which yields three different binary hypothesis testing problems. The testing problems are solved by means of the generalized likelihood ratio tests (GLRTs) and the locally most powerful invariant tests (LMPITs), which can be derived even without requiring an explicit expression for the maximal invariant statistics. Some simulation examples illustrate the performance of the proposed tests, which allows us to conclude that, for moderate sample sizes, it is advisable to use the LMPITs.This work was supported by the Spanish Government, Ministerio de Ciencia e Innovación (MICINN), under projects COSIMA (TEC2010-19545-C04-03) and COMONSENS (CSD2008-00010, CONSOLIDERINGENIO 2010 Program)

A novel particle tracking and break-up detection algorithm: application to the turbulent break-up of bubbles

A new method has been developed to measure experimentally the break-up properties of bubbles. The technique is based on the application of a particle tracking velocimetry algorithm to high-speed video images not only to measure the velocity of the bubbles, but also to detect the break-up events. Thus the algorithm is able to associate every broken bubble with the daughter bubbles formed upon their corresponding break-up. Moreover, the lifetime, as well as the number and size of fragments resulting from the break-up process, can be measured for a large number of bubbles. Statistical processing of the information collected allows us to compute the break-up frequency and daughter size distribution of the bubbles as a function of the bubble size and the mean properties of the base flow. The method has been employed to study the break-up of a cloud of bubbles injected at the central axis of a turbulent water jet. Experimental results for the break-up frequency and daughter bubble size distribution are also presented to illustrate the performance of the technique

Design, fabrication and characterization of photonic crystals on III-V compounds: from classical to quantum light sources

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de Materiales. Fecha de lectura: 11-12-200

Cómo buscar y usar información científica: Guía para estudiantes universitarios 2016.

This text, addressed to higher education students, provides guidelines on scholarly information and literature; how to select and assess reliability of web contents; how to access credible and refereed information; how to take advantage of academic library resources and services; which genres of scientific publications are there and how to use them; how to find and gather materials on a research topic; which search tools may be chosen; how to use fairly and efficiently the information resources; how to manage references and documents; how to analyze and work with them; how to cite and reference items; and how to organize and shape academic assignments and dissertations

Spanish version of the Coping Strategies Inventory

Introducción. En el presente trabajo acometimos la adaptación del Inventario de Estrategias de Afrontamiento (CSI) al ámbito español. Esta necesidad se justifica, por una parte, por la escasez y las limitaciones de los instrumentos disponibles en nuestro idioma, y por otra, por las excelentes potencialidades que ofrece el CSI. Método. Fue traducido y aplicado a una muestra de 337 personas adultas de características sociodemográficas diversas, recogida de forma incidental en actividades formativas en la provincia de Sevilla. Resultados. Los resultados mostraron unas excelentes propiedades psicométricas superando incluso las del estudio original: ocho factores explicaron un 61 % de la varianza con sólo 40 ítems (frente a los 72 que explicaban un 47% en el instrumento original) y obtuvieron coeficientes de consistencia interna entre 0,63 y 0,89. La validez convergente se comprobó utilizando las intercorrelaciones entre escalas y las correlaciones con disposiciones de personalidad (NEO-FFI) y eficacia percibida del afrontamiento. Conclusiones. El CSI se comportó de forma válida y fiable en la evaluación de la utilización de estrategias de afrontamiento en una amplia variedad de situaciones.Introduction. The aim of the present study was to adapt the Coping Strategies Inventory (CSI) to the Spanish setting. This need is justified on the one hand by the shortage and limitations of the instruments available in our language and, on the other, by the excellent potentialities that the CSI offers. Method. It was translated and applied to a sample of 337 adults, with diverse demographic characteristics, recruited from different teaching activities by the authors in the province of Seville (Spain). Results. The results showed excellent psychometric properties surpassing those of the original study: eight factors accounted for 61% of variance with only 40 items (as opposed to the 72 that accounted for 47% in the original study) and obtained Alpha coefficients between 0.63 and 0.89. The convergent validity was verified using intercorrelations between scales, correlations with personality dispositions (NEO-FFI) and with the coping efficacy. Discussion. The CSI was a valid and reliable measure of coping strategies used in many stressful situations

Mediación semántica A* basada en MDE para la generación de arquitecturas en tiempo de ejecución

Existen aplicaciones software que necesitan ser adaptadas en tiempo de ejecución debido a que los componentes que conforma su arquitectura no representan la configuración óptima. En estos casos, las arquitecturas deben ser reconfiguradas, por ejemplo, añadiendo y eliminando componentes, o modificando las relaciones entre ellos. Este artı́culo presenta una propuesta para la generación de arquitecturas en tiempo de ejecución. Está enfocado en la descripción del proceso que ocurre desde que existe una definición de arquitectura que hay que resolver, hasta que se genera la mejor configuración que da solución a dicha arquitectura. Para construir dicha configuración, se utilizan técnicas de modelado, mecanismos de trading y un algoritmo de búsqueda A*. Dicho algoritmo hace uso de una heurı́stica basada en la información sintáctica y semántica de los componentes. Como dominio de aplicación, se muestra un caso estudio para la generación de interfaces de usuario

Node activity monitoring in heterogeneous networks using energy sensors

In Heterogeneous Networks, small cells are usually deployed without operator supervision. Their proper operation highly depends on their self-adaptation capability, especially in dense HetNets where various small cells coexist in the same macrocell. This capability requires the small-cell base stations to continuously sense the radio environment, so they can dynamically adapt their operational setting (e.g. transmission power, carrier/channel selection, etc.) to the environmental conditions. In this work we propose a new method for a small base station to monitor the activity of the rest of nodes in the macrocell. We consider a centralized sensing procedure based on the fusion of the energy levels measured by the users of the small cell at their locations. In particular, we present an efficient algorithm that enables the small base station to monitor the activity of the rest of nodes. In addition, the algorithm also provides the gain of the channels between the nodes and the users of the small cell.This work has been funded by the Ministerio de Economía, Industria y Competitividad (MINECO) of Spain under grant TEC2017-86921-C2-1-R (CAIMAN) and under the KERMES Network (TEC2016-81900-REDT/AEI)

Fabrication and characterization of 2D photonic crystals for new optoelectronic devices

Photonic crystals were discovered in the 80s as a possible solution to the control of the spontaneous emission and localization of light. Nevertheless only in recent years, with the spreading of nanotechnologies, the first applications with high technological impact have been achieved, like planar photonic crystal lasers or the nanostructured photonic crystal waveguides. Nowadays new types of optoelectronic devices like single photon emitters based on photonic crystal nanocavities are being pursued. In this talk we will show the fabrication and characterization of new photonic bandgap devices, like Suzuki-phase laser emitters or ring-like emitters, and we will show their emission properties in the far field and their tuning by the fabrication process. These new devices may be used as new optical sensors and as efficient nanosources of laser light.Los cristales fotónicos fueron planteados a finales de los años ochenta como una posible solución al control de la emisión espontánea y a la localización de la luz. Sin embargo, sólo en los últimos años, con el advenimiento de las tecnologías de nanofabricación, se han conseguido las primeras aplicaciones prácticas de elevado impacto tecnológico, como los láseres de cristal fotónico o las guías de onda nanoestructuradas con gap fotónico. En la actualidad se están planteando nuevos dispositivos que permitan la emisión eficiente de un solo fotón o la captura de un átomo en el interior de una nanocavidad de cristal fotónico. En este seminario se mostrará la fabricación y caracterización de nuevos dispositivos con gap fotónico, como emisores láser de fase Suzuki o resonadores láser de anillo, y se mostrarán sus propiedades de emisión en el campo lejano y de sintonización mediante el control preciso del proceso de fabricación. Estos nuevos dispositivos pueden ser usados como nuevos sensores ópticos y como eficientes nanoemisores de luz láser.A. R. Alija agradece una beca predoctoral FPU AP2002-0474 del MEC. L. J. Martínez agradece una beca predoctoral I3P-CSIC. P. A. Postigo agradece un contrato "Ramón y Cajal" y los proyectos CAM GR\MAT\0729\2004 y CICYT TIC2002- 04096-C03-03.Peer reviewe

Optimised design of foundations for wind towers

Environmental, political, and other considerations are leading to the installation of growing numbers of wind turbines for electricity generation. The present paper concentrates on onshore installations, in which the turbine is placed at the end of a tower founded on the ground. A serious problem with the foundation or its connection with the tower entails a global failure. A worrying percentage of the towers built before 2010 is ill designed, often with obvious manifestations of the design problem. On the other hand the new designs attempt to optimise material quantities and costs while providing an adequate behaviour under the demands imposed. Principia has gathered considerable experience in both the identification and remediation of the problems experienced by older foundations and the optimisation of new designs. The problem is particularly suitable for numerical simulations with Abaqus and the paper provides the necessary concepts and methodological approach for a reliable and satisfactory solution. More specifically, the concrete geometry is meshed with solid elements. Surface elements including rebar layers are embedded. Other parts of the structure as the steel cylinder, welded studs, anchorage bars, etc. are also included. The concrete behaviour is described with the Abaqus concrete damaged plasticity model. Abaqus/Explicit is used because of the strong non-linearities, mainly caused by concrete cracking and crushing. The methodology allows assessing the suitability of the design for ultimate, serviceability and fatigue limit states