1,763 research outputs found
Exploring the benefits of multipath TCP In wireless networks
The revolution of the information society has created a completely new situation in the
telecommunications markets. As the average user data demands in today's society grow bigger,
since users nowadays are demanding a faster, wider and more reliable communication service
from the operators so they can watch more videos, listen to more music or access the Internet
in general with a better quality, a lower latency and seamlessly to the network access they are
using, the network operators face the challenge to fit this demands into their existing networks.
This has forced the operators to think in terms of how optimal they are on providing their
services if they want to fulfil the customer requirements in this new environment.
At the same time we need to keep in mind that simultaneously to this new user's habits
smartphones revolution has created, it has also made it possible to have accessible communication
devices which have the necessary hardware and horsepower to keep different network
interfaces up, and so it has become a common thing to reach the Internet via different kind of
networks along the day. Even more it has enabled a rich communications environment where
different connection possibilities are available to the user at the same time.
In this context, the idea of multipath communication emerges. The idea of taking advantage
of a dense wireless communication offer through the use of multipath (sending and receiving
information through different network interfaces simultaneously) looks promising to overcome a
situation where user's communications services demand grows and at the same time the mobile
network load becomes stronger. The newfangled protocol Multipath TCP (MPTCP) is a technology
which is enabling in practice this king of multipath communication, and it is the focus
of this project to dig into possible benefits the protocol may bring to the table by defining a
set of use cases, test-bed implementations and experiments with MPTCP which we present and
analyse in this document.La revolución de la sociedad de la información ha creado una situación que es completamente
nueva en los mercados de telecomunicaciones. A medida que el usuario medio aumenta su
demanda de datos, ya que hoy en día los hábitos de estos pasan por conexiones más rápidas y
fiables que les permitan reproducir contenido (video, música, páginas web) con mejor calidad,
menor latencia y transparentemente a la red que estén utilizando, los operadores de red afrontan
nuevos retos a la hora de encajar estas expectativas del usuario dentro de las posibilidades que
ofrece la red. Esto está forzando a los operadores a buscar una manera más óptima de gestionar
el tráfico de sus clientes para así poder satisfacer la demanda de unos servicios de mayor calidad
que estos realizan.
Al mismo tiempo hay que tener en mente que, de la misma manera que el impacto que esta
esta revolución de los smartphones ha tenido en los hábitos de consumo del usuario ha creado
nuevos y complejos problemas, también ha hecho posible que existan dispositivos económicamente
accesibles para el público con el hardware y la capacidad de procesamiento necesarias para incorporar
múltiples adaptadores de red, y esto a su vez ha llevado a al escenario actual en el
que comúnmente coexisten en el mismo lugar diferentes posibilidades para conectarse a internet
(típicamente Wi-Fi y conexión móvil, pero también podríamos nombrar tecnologías como el
Bluetooth o la clásica conexión de Ethernet en ordenadores portátiles)
Es en este contexto en el que surge la idea de la comunicación multi-trayecto. La idea
de aprovechar un entorno con una densa pero heterogénea oferta de conexión a través del
uso del multi-trayecto (enviar y recibir información a través de múltiples interfaces de red simultáneamente) aparece como una posibilidad prometedora para los operadores para mejorar
la experiencia del usuario al mismo tiempo que se gestiona el tráfico en la red de una manera
más eficiente.
El protocolo experimental Multipath TCP es una extensión del TCP clásico que hace posible
este uso simultáneo de múltiples interfaces para la comunicación, y es objetivo de este proyecto
diseñar, implementar y testear el protocolo en diferentes casos de uso en los que el multi-trayecto
ofrece, a priori, algunas ventajas. En las siguientes páginas explicaremos que casos de uso hemos
elegido para probar el protocolo y por qué, cómo hemos diseñado e implementado los bancos
de pruebas y que resultados hemos obtenido en nuestro experimentos sobre el rendimiento del
protocolo, realizando al mismo tiempo un análisis crítico de los resultados de los resultados.Ingeniería de Telecomunicació
Geoturismo de la Fuente de Cibeles de Madrid. Historia, piedra de construcción y canteras
[Abstract] Fuente de Cibeles of Madrid (Spain) represents Cybele goddess sitting on a carriage drawn by two lions. This sculptural set was carved in Montesclaros (Toledo-Spain) marble between 1777 and 1782. The sculptural set has experienced some modifications throughout its history. Two zoomorphic water-spouts carved in Colmenar de Oreja limestone, one in the shape of a dragon and another one in the shape of a bear, were installed in 1798. In 1895, the fountain changed of location, and two putti of Carrara marble were installed on the back of the fountain, expanding the rocky surface promontory on which the sculptural set stands. Two tiered basins made of granite were added in 1968, when the fountain acquired its current form.A geotouristic route was created based on Fuente de Cibeles and its main building stone, Montesclaros marble. An exhaustive description of the fountain was made, and its construction history was reviewed to elaborate the route. In this way, alternatives that diversify the conventional tourist options of the city of Madrid are presented. In addition, scientific data on historical quarries and the marble that forms part of the emblematic fountain is provided.[Resumen] La fuente de Cibeles de Madrid (España) representa a la diosa Cibeles sentada en un carruaje tirado por dos leones. Este conjunto escultórico fue tallado principalmente en mármol de Montesclaros (Toledo-España) entre los años 1777 y 1782 y a lo largo de su historia ha experimentado diversas modificaciones. En el año 1798 se instalaron dos surtidores zoomorfos, uno con forma de dragón y otro con forma de oso, tallados en la caliza de Colmenar de Oreja. La fuente se trasladó unas decenas de metros en el año 1895. En esa obra se elevó todo el conjunto escultórico y se instalaron dos putti de mármol de Carrara en la parte de atrás del carruaje, ampliando la superficie del promontorio rocoso sobre el que se asienta el conjunto escultórico. La fuente adquirió su forma actual en el año 1968; cuando se añadieron dos vasos escalonados de granito.A partir de la Fuente de Cibeles y su principal piedra de construcción, el mármol de Montesclaros, se creó una ruta geoturística. Una descripción exhaustiva, las fases de construcción y alteraciones de la fuente se presentan para completar la ruta por Montesclaros y zonas cercanas. De esta forma, se crean alternativas que diversifican las opciones turísticas convencionales de la ciudad de Madrid. Además, se aportan datos científicos sobre las canteras históricas y el mármol que forma parte de la emblemática fuente.Fundação para a Ciência e a Tecnologia (Portugal); CEECIND/03568/201
Biblioteca Municipal como laboratorio de apropiación espacial
The park “el Arbolito” was one of the first pieces of public space in Quito, becoming an
important part of the general scheme of the city. However, over the years, it has remained as a
residual space and a bit isolated, caged between two main avenues and behind “la Casa de la
Cultura Ecuatoriana”. This has caused the park to take a hostile tone and therefore unused.El parque “el Arbolito” fue una de las primeras piezas de espacio público de Quito,
convirtiéndose en una parte importante del esquema general de la ciudad. Sin embargo, con el
pasar de los años, ha quedado como un espacio residual y un poco aislado, enjaulado entre dos
avenidas principales y a la espalda de la Casa de la Cultura Ecuatoriana. Esto ha provocado
que el parque tome un tono hostil y que por lo tanto no sea utilizado
Provenance for computational tasks: a survey
Journal ArticleThe problem of systematically capturing and managing provenance for computational tasks has recently received significant attention because of its relevance to a wide range of domains and applications. The authors give an overview of important concepts related to provenance management, so that potential users can make informed decisions when selecting or designing a provenance solution
VisComplete: automating suggestions for visualization pipelines
Journal ArticleBuilding visualization and analysis pipelines is a large hurdle in the adoption of visualization and workflow systems by domain scientists. In this paper, we propose techniques to help users construct pipelines by consensus-automatically suggesting completions based on a database of previously created pipelines. In particular, we compute correspondences between existing pipeline subgraphs from the database, and use these to predict sets of likely pipeline additions to a given partial pipeline. By presenting these predictions in a carefully designed interface, users can create visualizations and other data products more efficiently because they can augment their normal work patterns with the suggested completions. We present an implementation of our technique in a publicly-available, open-source scientific workflow system and demonstrate efficiency gains in real-world situations
The Role of Cytoplasmic mRNA Cap-Binding Protein Complexes in Trypanosoma brucei and Other Trypanosomatids.
Trypanosomatid protozoa are unusual eukaryotes that are well known for having unusual ways of controlling their gene expression. The lack of a refined mode of transcriptional control in these organisms is compensated by several post-transcriptional control mechanisms, such as control of mRNA turnover and selection of mRNA for translation, that may modulate protein synthesis in response to several environmental conditions found in different hosts. In other eukaryotes, selection of mRNA for translation is mediated by the complex eIF4F, a heterotrimeric protein complex composed by the subunits eIF4E, eIF4G, and eIF4A, where the eIF4E binds to the 5'-cap structure of mature mRNAs. In this review, we present and discuss the characteristics of six trypanosomatid eIF4E homologs and their associated proteins that form multiple eIF4F complexes. The existence of multiple eIF4F complexes in trypanosomatids evokes exquisite mechanisms for differential mRNA recognition for translation
Investigating the potential of energy flexibility in an office building with façade BIPV and a PV parking system
Building Integrated Photovoltaic (BIPV), is becoming an attractive solution in the
context of high penetration of photovoltaic systems in buildings caused by the strive to
achieve net or nearly zero energy status. Besides retrieving solar radiation to produce
electrical energy, BIPV also offers aesthetical advantages because of its architectural feature.
However, when integrated into vertical façades, the angle of the Photovoltaic (PV)
modules may considerably affect the efficiency of BIPV when compared with horizontally
oriented modules in the same location and latitude.
This work reports on the electric energy performance of an office building, Solar XXI,
located in Lisbon, Portugal, based on the opportunity of having two PV technologies in
the same building. The system installed on the south façade is a BIPV (12 kWp) and the
second is a parking lot PV installed in a nearby car park facility (12 kWp). This situation
enables the comparison of Load Match Factors, but mainly Load Match Index, between
the two systems. The use of small scale loads in energy flexibility operational measures
to study the potential for flexible demand on an Net-Zero Energy Building (NZEB) office
building is also possible. Two different scenarios were taken into development, from
monitoring data obtained during March 2016 (winter period) and July 2016 (summer
period). PVGIS is a tool used to verify the possibility of a PV optimization in the parking
lot PV and EnergyPlus is used to create an energy consumption model of the building
aiming to be validated by the real values
Cellular Time Activation Networks, a novel approach applied to photovoltaic anomaly detection
The millisecond pulsar mass distribution: Evidence for bimodality and constraints on the maximum neutron star mass
The mass function of neutron stars (NSs) contains information about the late
evolution of massive stars, the supernova explosion mechanism, and the
equation-of-state of cold, nuclear matter beyond the nuclear saturation
density. A number of recent NS mass measurements in binary millisecond pulsar
(MSP) systems increase the fraction of massive NSs (with M)
to of the observed population. In light of these results, we
employ a Bayesian framework to revisit the MSP mass distribution. We find that
a single Gaussian model does not sufficiently describe the observed population.
We test alternative empirical models and infer that the MSP mass distribution
is strongly asymmetric. The diversity in spin and orbital properties of
high-mass NSs suggests that this is most likely not a result of the recycling
process, but rather reflects differences in the NS birth masses. The asymmetry
is best accounted for by a bimodal distribution with a low mass component
centred at M and dispersed by
M, and a high-mass component with a mean of
and a dispersion of
M. We also establish a lower limit of M
at 98% C.L. for the maximum NS mass, from the absence of a high-mass truncation
in the observed masses. Using our inferred model, we find that the measurement
of 350 MSP masses, expected after the conclusion of pulsar surveys with the
Square-Kilometre Array, can result in a precise localization of a maximum mass
up to 2.15 M, with a 5% accuracy. Finally, we identify possible
massive NSs within the known pulsar population and discuss birth masses of
MSPs.Comment: submitted to ApJ; 21 pages in aastex6 two-column format, 12 figures,
5 tables. Comments are welcom
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