74 resultados para preliminary communication
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Peer reviewed
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In numerical linear algebra, students encounter earlythe iterative power method, which finds eigenvectors of a matrixfrom an arbitrary starting point through repeated normalizationand multiplications by the matrix itself. In practice, more sophisticatedmethods are used nowadays, threatening to make the powermethod a historical and pedagogic footnote. However, in the contextof communication over a time-division duplex (TDD) multipleinputmultiple-output (MIMO) channel, the power method takes aspecial position. It can be viewed as an intrinsic part of the uplinkand downlink communication switching, enabling estimationof the eigenmodes of the channel without extra overhead. Generalizingthe method to vector subspaces, communication in thesubspaces with the best receive and transmit signal-to-noise ratio(SNR) is made possible. In exploring this intrinsic subspace convergence(ISC), we show that several published and new schemes canbe cast into a common framework where all members benefit fromthe ISC.
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Societies exchange knowledge, ideas and merchandise throughout their territories. Topography plays a fundamental role in the trajectory of such movements whilst helping to explain the distribution of human constructions. Standard GIS functions have been employed widely to simulate communication routes between settlements, but the straight application of published least cost route models proved inadequate for Mediterranean alluvial plain areas in which seasonal floods become an important factor to acknowledge. The objective of this study is the production of a new model, using topographic and hydrologic factors as variables from which it would be possible to simulate a route, and test it against known Roman itineraries. The selected Roman stretches are Girona – Coll de Pannisars and Tarragona – Montblanc. The new model shows the need to consider each case individually but also stresses the hydrologic factor, expressed in seasonal floods, as being of prime importance in the creation and development of Roman roads in Mediterranean alluvial plains.
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En este trabajo se investiga la persistencia de las estimaciones puntuales subjetivas de rendimientos en cultivos anua- les realizadas por un amplio grupo de agricultores. La persistencia en el tiempo es una condición necesaria para la co- herencia y la confiabilidad de las estimaciones subjetivas de variables aleatorias. Los sujetos entrevistados estimaron valores puntuales de rendimientos de cultivos anuales (rendimientos medio, mayor, mínimo y más frecuente). Se han encontrado diferencias relativas poco importantes en todas las variables, excepto en los rendimientos mínimos, donde existe una alta dispersión. Los resultados son interesantes para estimar la adecuación de las técnicas de estimación de probabilidades subjetivas para ser utilizadas en los sistemas de ayuda en la toma de decisiones en agricultura.
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La industria de la producción de camarón es una de las industrias acuícolas que se encuentra en más crecimiento en la actualidad. Los estudios para encontrar marcadores genéticos son muy efectivos para la mejora de sus propiedades y de gran interés para los productores de camarón. En este trabajo se utilizaron seis individuos de una población de Litopenaeus vannamei, donde se encontraron cuatro polimorfismos de nucleótido único (SNPs) en el gen 5HT1R (5-hidroxitriptamina receptor1) y un SNP en el gen STAT (transductor de señal y activador de la transcripción). Sin embargo, el polimorfismo en el gen STAT resultó ser homocigoto en una población diferente utilizada para análisis de asociación. Los presentes análisis revelaron que el alelo C, en dos polimorfismos SNP (C109T y C395G) del gen 5HT1R, tiende a estar asociado con el aumento del peso corporal. Consideramos que hay necesidad de hacer nuevos estudios utilizando una muestra más amplia y diversa de la población en cuestión.
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In previous studies, we demonstrated cross-antagonism in pheromone perception between pheromone componentsof the two corn (Zea mays L.) borers Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae) and Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) in the laboratory and in the field. The two pheromone components identified as responsible for this cross-antagonism were Z 11-16:Ald, a minor component of S. nonagrioides pheromone, and Z 11-14:Ac, the main component of the pheromone of the Z-strain of O. nubilalis, which inhibited the response of O. nubilalis and S. nonagrioides, respectively. Here, we study this antagonism phenomenon in the field by air permeation of maize plots with each of the two components separately and measurement of mating in caged couples of the two corn borers on treated and untreated plots during three years. A significant reduction in mating rates was observed on the permeated plots: 7% for S. nonagrioides and 12% for O. nubilalis. When dispenser charges (200 ng) were increased by 50% and 75% in the third year, no decrease in mating rates was recorded at either of the increased concentrations. On the other hand, the use of large cages resulted in an increase of 8% to 12% in the percentage of unmated females in each of the two corn borers suggesting that at more realistic field corn borer densities, 0,1 couples/plant instead of the 2 couples/plant used in this experiment, cross-antagonism in the two corn borers could be higher than that recorded in small cages.
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Spain is one of the countries with the highest greenhouse gas (GHG) emissions within the EU-27. Consequently, mitigation strategies need to be reported and quantified to accomplish the goals and requirements of the Kyoto Protocol. In this study, a first estimation of the carbon (C) mitigation potential of tillage reduction in Mediterranean rainfed Spain is presented. Results from eight studies carried out in Spain under rainfed agriculture to investigate the effects of no-tillage (NT) and reduced tillage (RT) compared with conventional tillage (CT) on soil organic carbon (SOC) were used. For current land surface under conservation tillage, NT and RT are sequestering 0.14 and 0.08 Tg C yr-1, respectively. Those rates represent 1.1% and 0.6% of the total CO2 emissions generated from agricultural activities in Spain during 2006. Alternatively, in a hypothetical scenario where all the arable dryland was under either NT or RT management, SOC sequestration would be 2.18 and 0.72 Tg C yr-1 representing 17.4% and 5.8% of the total 2006 CO2 equivalent emissions generated from the agricultural sector in Spain. This is a significant estimate that would help to achieve GHG emissions targets for the current commitment period of the Kyoto Protocol.
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Aim of study: To identify species of wood samples based on common names and anatomical analyses of their transversal surfaces (without microscopic preparations). Area of study: Spain and South America Material and methods: The test was carried out on a batch of 15 lumber samples deposited in the Royal Botanical Garden in Madrid, from the expedition by Ruiz and Pavon (1777-1811). The first stage of the methodology is to search and to make a critical analysis of the databases which list common nomenclature along with scientific nomenclature. A geographic filter was then applied to the information resulting from the samples with a more restricted distribution. Finally an anatomical verification was carried out with a pocket microscope with a magnification of x40, equipped with a 50 micrometers resolution scale. Main results: The identification of the wood based exclusively on the common name is not useful due to the high number of alternative possibilities (14 for “naranjo”, 10 for “ébano”, etc.). The common name of one of the samples (“huachapelí mulato”) enabled the geographic origin of the samples to be accurately located to the shipyard area in Guayaquil (Ecuador). Given that Ruiz y Pavon did not travel to Ecuador, the specimens must have been obtained by Tafalla. It was possible to determine correctly 67% of the lumber samples from the batch. In 17% of the cases the methodology did not provide a reliable identification. Research highlights: It was possible to determine correctly 67% of the lumber samples from the batch and their geographic provenance. The identification of the wood based exclusively on the common name is not useful.
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This paper presents the quantitative and qualitative findings from an experiment designed to evaluate a developing model of affective postures for full-body virtual characters in immersive virtual environments (IVEs). Forty-nine participants were each requested to explore a virtual environment by asking two virtual characters for instructions. The participants used a CAVE-like system to explore the environment. Participant responses and their impression of the virtual characters were evaluated through a wide variety of both quantitative and qualitative methods. Combining a controlled experimental approach with various data-collection methods provided a number of advantages such as providing a reason to the quantitative results. The quantitative results indicate that posture plays an important role in the communication of affect by virtual characters. The qualitative findings indicated that participants attribute a variety of psychological states to the behavioral cues displayed by virtual characters. In addition, participants tended to interpret the social context portrayed by the virtual characters in a holistic manner. This suggests that one aspect of the virtual scene colors the perception of the whole social context portrayed by the virtual characters. We conclude by discussing the importance of designing holistically congruent virtual characters especially in immersive settings.
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Analysis of the interaction between landscape and the individual opens up many research avenues linked to the generation and interpretation of symbolisms and imaginaries. The capacity of landscape for significant and/or communicative evocation finds in intrapersonal communication a relevant argument for the construction of a theoretical framework to study the process of appropriation and experience of the landscape in terms of communicative expression. The principal aim of this paper is to set up the theoretical framework that enables us to interpret the language of landscape and to decode its intangible discourse.
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The Lorca basin is one of the Neogene basins OS South Eastern Spain. The infilling Tortonian-Messinian deposits are mainly composed OS marls and reach up to 1,200 m in thickness. A biostratigraphic survey OS these deposits, assisted by the determination OS the magnetic polarity reversal pattern Sor most OS these deposits (900 m), has enabled the Tortonian-Messinian chronostratigraphy to be precised. The close sampling space for biostratigraphic determination has enabled the accurate location OS Sour main biostratigraphic events than can be correlated with charactenstic events of the Mediterranean biostratigraphic Zones. In addition, the location OS the TortonianNessinian boundary has been accurately placed at some 150 m below the main gypsurn unit outcropping in the basin. The integrated bio-magnetostratigraphic data fiom the studied section allows a tentative interpretation OS the identified magnetozones. Thus, a correlation to the Geomagnetic Polarity Time Scale is presented for more than 900 m of pre-evaporite Miocene stratigraphic succession fiom the Lorca basin. Moreover, about 15' OS anticlockwise rotation has been detected. Its significance is evaluated in the basin geodynamic framework.
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Este trabajo se inscribe en el ámbito de la prevención de la negligencia parental. Basado en un proceso teórico-práctico, el programa de intervención está sujeto a la línea de los programas de formación de padres, por lo que sigue una dinámica psico-educativa y comunitaria. Para la realización del trabajo se ha partido de la idea que la familia es la base del desarrollo personal de los humanos y que el buen desarrollo de los menores dependerá en gran parte de las relaciones intrafamiliares. Se establece como objetivo principal ofrecer un servicio específico, estable y continuo, vinculado a los servicios de atención a la infancia y a la familia, que trabaje con el fin de conseguir un cambio conductual en aquellas familias en las que se presente una dinámica parental negligente. La metodología utilizada ha combinado diferentes técnicas de investigación. Para el trabajo de documentación se ha realizado una búsqueda bibliográfica alrededor del concepto de negligencia parental, se han analizado las acciones que se llevan a cabo a nivel institucional y se ha establecido el marco conceptual en el que se incluye tanto los aspectos legal de las diferentes áreas de la administración como aquellos conceptos que forman la estructura de una intervención en el ámbito de la infancia y la familia. También se ha tenido en cuenta la comunicación directa con algunos profesionales del ámbito social, sanitario y educativo como parte importante y determinante del proceso de ejecución del programa. El diseño del programa sigue la metodología del planeamiento estratégico e incluye un diagnóstico preliminar, un plan de acción detallado de las diferentes fases de implementación de la propuesta de intervención, la previsión de mecanismos de evaluación y un presupuesto detallado. En la primera parte del trabajo se refleja la gravedad y el impacto que tiene la negligencia parental en nuestra sociedad, observando la evolución histórica del concepto y la visualización de la problemática a la que va asociado. También se expone la necesidad de crear programas destinados a trabajar esta problemática y una revisión del marco legal que regula la atención a la infancia por parte de las administraciones públicas. En una segunda parte, se propone un programa específico destinado a trabajar la negligencia parental desde una perspectiva de reeducación y cambio conductual. Este proyecto de intervención se ubica en el barrio de Can Rull en Sabadell, del cual se detallan sus especificidades socioeconómicas y su realidad institucional.
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Los estudios sobre el uso de las tecnologías de la información y comunicación (TIC) para organizar el trabajo y sobre su incidencia en la conciliación entre vida laboral y familiar arrojan resultados ambiguos o contradictorios. Sin embargo, la aparición y la difusión de TIC inalámbricas están provocando intensos cambios en las prácticassociales, incluidas las relaciones entre vida personal y trabajo. Mediante entrevistas en profundidad, un grupo de padres en situaciones laborales diversas han reflexionado sobre cómo utilizan el potencial de movilidad, conectividad y flexibilidad que les ofrecen las nuevas TIC y sobre cómo modula dicho uso la implicación de los hombres en su rol de padres. En línea con trabajos realizados en otros países, los resultados preliminares sugieren que el papel que se atribuye a las TIC como herramientas para la emancipación del rol de género de los hombres mediante su mayor implicación en el cuidado material y afectivo de los hijos depende muchas veces de factores ajenos al uso de estas tecnologías: motivación personal, actitud y percepción de la pareja respecto a la competencia hombre para ejercer de padre, o macro y micro políticas de conciliación existentes en las organizaciones.
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Presentation at: II IAS Annual Research Programme International ConferenceSession: Governing Regions, Lancaster Setember 17-19 2007