2,856 research outputs found
A Data Fusion Technique to Detect Wireless Network Virtual Jamming Attacks
The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Wireless communications are potentially exposed to jamming due to the openness of the medium and, in particular, to virtual jamming, which allows more energy-efficient attacks. In this paper we tackle the problem of virtual jamming attacks on IEEE 802.11 networks and present a data fusion solution for the detection of a type of virtual jamming attack (namely, NAV attacks), based on the real-time monitoring of a set of metrics. The detection performance is evaluated in a number of real scenarios
Manejo integrado de Bromus diandrus. Resultados de tres años de ensayos
En el presente trabajo se aportan los resultados obtenidos
tras tres años de ensayos sobre estrategias de control de Bromus diandrus
en una zona en la que se cultivan principalmente cereales en siembra
directa. Se han rotado, durante los tres años, tres cultivos diferentes
con diversos herbicidas para cada uno, lo cual ha permitido diversificar
tanto las fechas de siembra, de octubre a enero, como los herbicidas utilizados.
El guisante y la cebada, por la siembra tardía, han permitido disminuir
las infestaciones de bromo. Además, la eficacia de los herbicidas
selectivos del guisante es significativamente superior a la de los autorizados
en trigo. El rendimiento del trigo en “rotación” ha sido muy superior
al del trigo en “monocultivo” considerado como estándar. El rendimiento
del guisante ha sido aproximadamente del 55% del trigo en rotación, lo
que garantiza su rentabilidad económica. También el rendimiento de la
cebada, sembrada tras guisante, ha sido muy superior al del trigo.In this paper the results of a
three year experiment for Bromus diandrus management strategies, carried
out in a winter cereal area under no-tillage, are provided. The managements
combine three different crops during three years with various
herbicides for each crop. Sowing dates have been diversified from October
to January, as well as the herbicides. Field pea and barley, by the
fact that are sown late in the season, have reduced Brome infestations.
Moreover, the efficacy of selective herbicides for field pea is significantly
higher than those authorized in wheat. Wheat yield in “rotation” has
been much higher than in “monocrop”. Field pea yield was about 55%
of wheat in rotation, ensuring its profitability. Yield for barley sown after
pea, was also much higher than for wheat
existence and uniqueness results for quasi-linear elliptic equations with nonlinear boundary conditions
Energy solutions to one-dimensional singular parabolic problems with data are viscosity solutions
We study one-dimensional very singular parabolic equations with periodic
boundary conditions and initial data in , which is the energy space. We
show existence of solutions in this energy space and then we prove that they
are viscosity solutions in the sense of Giga-Giga.Comment: 15 page
A caricature of a singular curvature flow in the plane
We study a singular parabolic equation of the total variation type in one
dimension. The problem is a simplification of the singular curvature flow. We
show existence and uniqueness of weak solutions. We also prove existence of
weak solutions to the semi-discretization of the problem as well as convergence
of the approximating sequences. The semi-discretization shows that facets must
form. For a class of initial data we are able to study in details the facet
formation and interactions and their asymptotic behavior. We notice that our
qualitative results may be interpreted with the help of a special composition
of multivalued operators
Bromoxynil sensitivity study of a "Papaver rhoeas" L. biotype
“Papaver rhoeas” es la única mala hierba dicotiledónea que presenta resistencia múltiple en España. Se han detectado biotipos resistentes a tribenuron-metil (inhibidor de la acetolactato sintasa) y 2,4-D (auxina sintética). En la zona cerealista del norte de España ha habido problemas en el control de esta mala hierba con mezclas que contenían bromoxinil. En el presente trabajo se ha ensayado, con curvas dosis-respuesta, el efecto de este producto en dos lotes de semillas de un biotipo que no fue controlado en campo por mezclas con bromoxinil en dos años consecutivos. Los lotes B-0313 y B-0314 fueron controlados cuando el bromoxinil se aplicó a la fenología recomendada. Se observó cierto desplazamiento de la curva cuando las plantas de amapola se aplicaron a fenologías más avanzadas.“Papaver rhoeas” is the unique dicot weed that has multiple
resistance in Spain. Resistant biotypes have been detected to tribenuron-
methyl (acetolactate synthase inhibitor) and 2,4-D (synthetic auxin).
In the cereal area of northern Spain there have been problems to
control this weed with mixtures containing bromoxynil. In the present
work we have tested the effect of this product in one biotype that was
not controlled in the field by herbicide mixtures with bromoxynil. The lots B-0313 and B-0314 were controlled with bromoxynil applied at the
recommended phenology. A shift in the curve was observed when corn
poppy plants were applied in more advanced phenologies
Validación durante cuatro años de un sistema experto para optimizar el uso de herbicidas en cereales de invierno en condiciones agronómicas españolas
CPOWeeds is a version of Danish Crop Protection online adjusted to conditions in North-eastern Spain. The predicted efficacies and the yield obtained with CPOWeeds were validated in winter cereal field trials from 2010 to 2013. The predictions from CPOWeeds were compared to the actually achieved efficacies in the field trials for the nine weed species at different developmental stages and for 84.2% of the comparisons the obtained efficacies were equal to or higher than predicted. It was concluded that the use of CPOWeeds allowed optimisation of the herbicide application with a very high robustness. The recommendations were satisfactorily for the conditions of the Northeast of Spain and have the potential to decrease the amount of applied herbicides by at least 30%. Therefore, it can be an important tool in Integrated Weed Management.El CPOWeeds es una versión del Crop Protection Online danés puesto a punto para las condiciones del noroeste (NE) de España. Las eficacias predichas por el programa se han validado en ensayos en cereal de invierno desde 2010 a 2013. Las predicciones dadas por el CPOWeeds se han comprobado para nueve especies de malas hierbas en diferentes estadios fenológicos y en el 84,2% de los casos las eficacias han sido iguales o superiores a las predichas. Se concluye que el uso del CPOWeeds permite optimizar la aplicación de herbicidas con una gran robustez. Las recomendaciones son satisfactorias para el NE de España y se puede disminuir la cantidad de herbicidas aplicados hasta en un 30%. Por tanto, se trata de una herramienta muy importante en el Manejo Integrado de Malas Hierbas
Optimal management of the Jucar River and Turia River basins under uncertain drought conditions
This paper presents a methodology to assess the best behavior achievable for a water resources system, and we apply it to the joint system of the Jucar River and Turia River basins in Spain. The resources of the two rivers are used jointly to meet the different water uses within the region, especially urban demands and environmental requirements. The climate change effects in this area are predicted to be particularly severe in this area with great variability in drought patterns. The results are particularly suitable for evaluating the best performance of the system under uncertain conditions
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