199,506 research outputs found
Payloads development for European land mobile satellites: A technical and economical assessment
The European Space Agency (ESA) has defined two payloads for Mobile Communication; one payload is for pre-operational use, the European Land Mobile System (EMS), and one payload is for promoting the development of technologies for future mobile communication systems, the L-band Land Mobile Payload (LLM). A summary of the two payloads and a description of their capabilities is provided. Additionally, an economic assessment of the potential mobile communication market in Europe is provided
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Da eccezione a eccesso: detenzione e deportazioni nello spazio del Mediterraneo
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Ubiquitous Internet in an integrated satellite-terrestrial environment: The SUITED solution
yesThe current Internet architecture appears to
not be particularly suited to addressing the
emerging needs of new classes of users who wish
to gain access to multimedia services made available
by ISPs, regardless of their location, while
in motion and with a guaranteed level of quality.
One of the main objectives of so-called nextgeneration
systems is to overcome the limitations
of today¿s available Internet by adopting an
approach based on the integration of different
mobile and fixed networks. The SUITED project
moves in this direction since it aims at contributing
to the design and deployment of the global
mobile broadband system (GMBS), a unique
satellite/terrestrial infrastructure ensuring
nomadic users access to Internet services with a
negotiated QoS. A description of the main features
of the GMBS architecture, characterized
by the integration of a multisegment access network
with a federated ISP network is given in
this article. The GMBS multimode terminal is
schematically described, and an overview of the
so-called QoS-aware mobility management
scheme, devised for such a heterogeneous scenario,is provided
Birational geometry of defective varieties
Here we investigate the birational geometry of projective varieties of
arbitrary dimension having defective higher secant varieties. We apply the
classical tool of tangential projections and we determine natural conditions
for uniruledness, rational connectivity, and rationality
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Andrea Pozzo e il Venerabile Collegio Inglese a Roma
This paper outlines the work of Andrea Pozzo for the Venerable English College in Rome. It explores the context of his work there facilitated by the Jesuit, Francesco Eschinardi, who was a member of the College staff
System test approach for the SAX satellite
SAX satellite verification is based on a protoflight approach, in which only one system model is realized at flight standard level, taking into account the utilization of hardware already qualified for other space programs and the necessity to respect the schedule constraints for a scientific objective. In any case, this approach was tailored with some deviations in order to reduce risks inherent in such a choice. The protoflight approach was also pursued at subsystem/unit level in particular for those subsystems and units considered critical from the schedule point of view. Payload Instruments followed the same approach but complete spare units were developed to reduce the risks associated with such an approach. A description of the model philosophy is provided and then, at satellite level, the testing approach and rationale for each model is presented. Finally, a brief description of each test will be given, highlighting objectives, methodologies, and test configurations. Moreover, for the major tests, problems encountered and solutions applied in establishing a correct approach are described
NaturWall©: facciate in legno multifunzionali per la riqualificazione del patrimonio edilizio / NaturWall©:multifunctional wood façade in existent building refurbishment
Naturwall© is a research conducted by Politecnico of Turin (DAD) (under supervision of Prof.G.Callegari) and a local PMI support (Natural House, Castellamonte), promoted by Giovanni Goria Foundation "Master dei Talenti" programme. It consists in an innovative energy saving system by using wood multifunctional components for existent buildings . The goal of the project is the refurbishment of the existing building stock which were built from 1950's to 1980's. This stock is not equipped with recent energy requirements. The project aims to create a representative model of solution that will be promoted in Italy. In the field of renovation and refurbishment high energy results and greenhouse gases reduction could be achieved by using multifunctional facade system
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