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91.
Giuseppe?TomasicchioEmail author Luigi?Secondiani Fabrizio?Di?Cola Emiliano?Micaloni 《Wireless Personal Communications》2005,35(1-2):71-86
The growing development of standard Internet services and the emerging exploitation of several broadband multimedia contents
disclosing in the last years, significantly promoted scenarios where Satellite Networks can play key roles. Several satellite
networks are currently implemented according to the Digital Video Broadcasting-Return Channel via Satellite (DVB-RCS) standard,
assuming to operate with a transparent satellite and an hub-centric (star) network topology.
The present work addresses the SkyplexNet (SKN) system: an advanced Broadband Satellite Network for meshed connectivity developed
by Alenia Spazio, within the framework of ESA Artes 3 – Line 1 Program, according to the DVB-RCS standard with duly extensions
for the on-Board multiplexing capability of the Skyplex Units currently embarked on HotBird VI and W3A satellites. In this
paper an architecture design study aiming at integrating the Medium Access Control (MAC) and Traffic Management (TM) functionality
in a DVB-RCS like Network is presented. The envisaged Traffic Management schemes shall enable the SKN System to guarantee
an adequate support of various Quality of Service (QoS) requirements and their application according to pre-defined Traffic
Profiles established at connection set up phase with the support of physical medium access management functions.
The functional architectures studied for the SKN Inter-Working Layer, from Internet protocols to SkyplexNet ones, and the
SKN MAC layer have been also analysed on the interoperability level of these layers in order to deploy such functions as SKN
connection mapping, packet scheduling and Bandwidth on Demand (BoD) policies.
In this paper two different schemes of Traffic Management and MAC are presented reporting a detailed analysis of advantages
and drawbacks of both approaches to be taken into account for future SkyplexNet system implementations.
Fabrizio Di Cola is a Network and System Engineer of the Telecommunication Mission Unit of Alenia Spazio company (Italy). He received the
M.S. degree in Telecommunication Engineering from University of Rome “La Sapienza” in 1998 and he is in Alenia Spazio since
2000. He is currently involved in the design and deployment of the Ground Segment of EuroSkyWay and SkyplexNet satellite systems
as responsible for the Satellite User terminals Design and Development. He also contributes to System Engineering in the framework
of several ESA and EC projects. From 1999 up to 2000, he worked as Researcher in the University of Bradford (Bradford, UK),
Telecommunication Research Centre, within the “Satellite Mobile Group”. His activity focused on several aspects of the Mobility
Management within telecommunications network integrating satellite and terrestrial networks.
Emiliano Micaloni was born in Rome, Italy, in 1977. He is a Junior Telecommunication System Engineer involved since 2003 in a collaboration
between University of Rome “La Sapienza” and the TLC Mission Unit of Alenia Spazio company (Italy). He received his Master
Degree in Electronic Engineering from the University of Rome “La Sapienza”, Italy, in 2002, defending a thesis on Connection
and Congestion Control for Geostationary Satellite Networks. Currently his area of interest concerns the Medium Access Control
in the SkyplexNet Satellite Network, also contributing at the development activities for the SkyplexNet Satellite Terminals.
In 2002–03 he collaborated with the “Computer Science and Systems” Department of “La Sapienza“ implementing solutions for
Traffic Management and Quality of Service in Satellite Networks. All his activities are carried out in the framework of different
ESA and EU IST projects.
Luigi Secondiani received his M.S. degree in Telecommunication Engineering from University of Rome “La Sapienza” in 1997. From 1998 to 1999
he received a post-degree grant issued by the “Infocom” Department of the University of Rome “La Sapienza” in the frame of
the ACTS 4th framework programme. Since December 1999 he works as a Network Engineer in Alenia Spazio-TLC Mission Unit, and
he is currently involved in Alenia's activities on EC, ESA and NATO programmes. His main research interests mainly lie on
interworking between Next Generation Satellite Systems (NGSS) and IP networks, with particular emphasis on network architectures,
terminal's architectures and routing issues.
Giuseppe Tomasicchio is a Senior Telecommunication System Engineer of the TLC Mission Unit of Alenia Spazio company (Italy). He received his degree
in 1989 from University of Bari (Italy) in the Artificial Intelligence field. He received a Post-degree Diploma on Technologies
of Educational Communication in 1991 and a Post-degree Engineering Specialisation Diploma in Signal Processing in 1994 from
University of Bari. Currently he is responsible of the Ground System Design of EuroSkyWay/SkyplexNet satellite systems and
of the Network Operations and Service Centres engineering in satellite networks devoted to multimedia applications in the
framework of different ESA and EC projects. In 1997–98 he was responsible at CERN (Geneva, Switzerland) of the Data Acquisition System involving the readout, calibration, event display and the networking setup tasks of high energy physics experiments. From 1994 to 1998 he was at INFN (Italian Institute for
Nuclear Physics) as researcher. In 1994 he was an IS-specialist in the Italian Government data processing centre and collaborated
with the Government Seismic Service for GIS processing. He worked in 1991–92 as a fellow of DIGITAL Corporation for a join
research activity at INFN in the field of Image processing and Pattern recognition applied to raw-data images produced from detectors in high energy physics experiments at CERN. He is author of several scientific
and engineering papers. 相似文献
92.
Bartolini L De Dominicis L de Collibus MF Fornetti G Guarneri M Paglia E Poggi C Ricci R 《Applied optics》2005,44(33):7130-7135
We report the results of underwater imaging with an amplitude-modulated single-mode laser beam and miniaturized piezoactuator-based scanning system. The basic elements of the device are a diode laser source at 405 nm with digital amplitude modulation and a microscanning system realized with a small-aperture aspheric lens mounted on a pair of piezoelectric translators driven by sawtooth waveforms. The system has been designed to be a low-weight and rugged imaging device suitable to operate at medium range (approximately 10 m) in clear seawater as also demonstrated by computer simulation of layout performance. In the controlled laboratory conditions a submillimeter range accuracy has been obtained at a laser amplitude modulation frequency of 36.7 MHz. 相似文献
93.
Thomas Bolander Hans van Ditmarsch Andreas Herzig Emiliano Lorini Pere Pardo François Schwarzentruber 《Journal of Logic, Language and Information》2016,25(1):1-35
In public announcement logic it is assumed that all agents pay attention to the announcement. Weaker observational conditions can be modelled in action model logic. In this work, we propose a version of public announcement logic wherein it is encoded in the states of the epistemic model which agents pay attention to the announcement. This logic is called attention-based announcement logic. We give an axiomatization of the logic and prove that complexity of satisfiability is the same as that of public announcement logic, and therefore lower than that of action model logic. An attention-based announcement can also be described as an action model. We extend our logic by integrating attention change. Finally, we add the notion of common belief to the language, we exploit this to formalize the concept of joint attention, that has been widely discussed in the philosophical and cognitive science literature, and we provide a corresponding axiomatization. This axiomatization also employs the auxiliary notion of attention-based relativized common belief. 相似文献
94.
Emiliano Re Andrew Murrell Damien Roques 《International Journal of Satellite Communications and Networking》2021,39(1):78-91
In the last five years, the satellite community has witnessed growing interest in the delivery of Broadband Services from non‐geostationary orbit (NGSO) systems. However, accessing the entire spectrum available without having to share it among the different operators is key for these systems to have a chance of breaking even, which makes for a challenging business case. This paper focuses on the challenges of spectrum coexistence of multiple satellite constellations for broadband communications and proposes a radio resource management algorithm to enable such coexistence. 相似文献
95.
Emiliano De Cristofaro Mark Manulis Bertram Poettering 《International Journal of Information Security》2013,12(1):49-65
Digital services that are offered, and consumed, on the basis of social relationships form the backbone of social clouds—an emerging new concept that finds its roots in online social networks. The latter have already taken an essential role in people’s daily life, helping users to build and reflect their social relationships to other participants. A key step in establishing new links entails the reconciliation of shared contacts and friends. However, for many individuals, personal relationships belong to the private sphere, and, as such, should be concealed from potentially prying eyes of strangers. Consequently, the transition toward social clouds cannot set aside mechanisms to control the disclosure of social links. This paper motivates and introduces the concept of Private Discovery of Common Social Contacts, which allows two users to assess their social proximity through interaction and learn the set of contacts (e.g., friends) that are common to both users, while hiding contacts that they do not share. We realize private contact discovery using a new cryptographic primitive, called contact discovery scheme (CDS), whose functionality and privacy is formalized in this work. To this end, we define a novel privacy feature, called contact-hiding, that captures our strong privacy goals. We also propose the concept of contact certification and show that it is essential to thwart impersonation attacks on social relationships. We build provably private and realistically efficient CDS protocols for private discovery of mutual contacts. Our constructions do not rely on a trusted third party (TTP)—all contacts are managed independently by the users. The practicality of our proposals is confirmed both analytically and experimentally on different computing platforms. We show that they can be efficiently deployed on smartphones, thus allowing ad hoc and ubiquitous contact discovery outside of existing social networks. Our CDS constructions allow users to select their (certified) contacts to be included in individual protocol executions. That is, users may perform context-dependent contact discovery using any subset (circle) of their contacts. 相似文献
96.
Targeting EphA2‐Sam and Its Interactome: Design and Evaluation of Helical Peptides Enriched in Charged Residues 下载免费PDF全文
Dr. Flavia A. Mercurio Dr. Daniela Marasco Dr. Concetta Di Natale Dr. Luciano Pirone Dr. Susan Costantini Dr. Emilia M. Pedone Dr. Marilisa Leone 《Chembiochem : a European journal of chemical biology》2016,17(22):2179-2188
The EphA2 receptor controls diverse physiological and pathological conditions and its levels are often upregulated in cancer. Targeting receptor overexpression, through modulation of endocytosis and consequent degradation, appears to be an appealing strategy for attacking tumor malignancy. In this scenario, the Sam domain of EphA2 plays a pivotal role because it is the site where protein regulators of endocytosis and stability are recruited by means of heterotypic Sam–Sam interactions. Because EphA2‐Sam heterotypic complexes are largely based on electrostatic contacts, we have investigated the possibility of attacking these interactions with helical peptides enriched in charged residues. Several peptide sequences with high predicted helical propensities were designed, and detailed conformational analyses were conducted by diverse techniques including NMR, CD, and molecular dynamics (MD) simulations. Interaction studies were also performed by NMR, surface plasmon resonance (SPR), and microscale thermophoresis (MST) and led to the identification of two peptides capable of binding to the first Sam domain of Odin. These molecules represent early candidates for the generation of efficient Sam domain binders and antagonists of Sam–Sam interactions involving EphA2. 相似文献
97.
An optoelectronic target-type volumetric air flow-rate transducer for bidirectional measurements is presented. The sensor is composed of a T-shaped target and two nominally identical LED-photodiode couples which are operated in differential mode. The sensitive surfaces of the photodiodes are differentially shadowed by the deflection of the target, which in turn depends on the gas flow-rate. The principle of operation is described in mathematical terms and the design parameters have been optimized in order to obtain the highest sensitivity along with minimal pressure drop and reduced dimensions. The sensor is placed in a 20 mm diameter hose and was tested with air flow-rate in the typical temperature range of mechanical ventilation between 20 and 40 °C. The theoretical model was validated through experiments carried out in the volumetric flow range from -7.0 to +7.0 l min(-1). The nonlinear behavior allows sensitivities equal to 0.6 V l(-1) min for flow rates ranging from -2.0 to +2.0 l min(-1), equal to 2.0 V l(-1) min for flow rates ranging from -3.0 to -2.0 l min(-1) and from +2.0 to +3.0 l min(-1), up to 5.7 V l(-1) min at higher flow rates ranging from -7.0 to -3.0 l min(-1) and from +3.0 to +7.0 l min(-1). The linear range extends from 3.0 to 7.0 l min(-1) with constant sensitivity equal to 5.7 V l(-1) min. The sensor is able to detect a flow-rate equal to 1.0 l min(-1) with a sensitivity of about 400 mV l(-1) min. The differential nature of the output minimizes the influence of the LEDs' power supply variations and allows to obtain a repeatability in the order of 3% of full scale output. The small pressure drop produced by the sensor placed in-line the fluid stream, of about 2.4 Pa at 7 l min(-1), corresponds to a negligible fluid dynamic resistance lower than 0.34 Pa l(-1) min. 相似文献
98.
Yi Liu Han Zhang Harshit Porwal Wei Tu Jamie Evans Mark Newton James J. C. Busfield Ton Peijs Emiliano Bilotti 《Advanced functional materials》2017,27(39)
Smart heating devices with reliable self‐regulating performances and high efficiency, combined with additional properties like mechanical flexibility, are of particular interest in healthcare, soft robotics, and smart buildings. Unfortunately, the development of smart heaters necessitates managing normally conflicting requirements such as good self‐regulating capabilities and efficient Joule heating performances. Here, a simple and universal materials design strategy based on a series connection of different conductive polymer composites (CPC) is shown to provide unique control over the pyroresistive properties. Hooke's and Kirchhoff's laws of electrical circuits can simply predict the overall pyroresistive behavior of devices connected in series and/or parallel configurations, hence providing design guidelines. An efficient and mechanically flexible Joule heating device is hence designed and created. The heater is characterized by a zero temperature coefficient of resistance below the self‐regulating temperature, immediately followed by a large and sharp positive temperature coefficient (PTC) behavior with a PTC intensity of around 106. Flexibility and toughness is provided by the selected elastomeric thermoplastic polyurethane (TPU) matrix as well as the device design. The universality of the approach is demonstrated by using different polymer matrices and conductive fillers for which repeatable results are consistently obtained. 相似文献
99.
Romina Paola Lancetti Emiliano Salvucci Candela Paesani Gabriela Teresa Pérez Lorena Susana Sciarini 《International Journal of Food Science & Technology》2022,57(8):4804-4815
The aim of this work was to evaluate the effect of two autochthonous strains of lactic acid bacteria as sourdough (SD) starters on gluten-free bread technological quality and in vitro starch hydrolysis and antioxidant activity. Two strains of Limosilactobacillus fermentum isolated from buckwheat (BW) and quinoa flours were used. SDs were prepared from wholegrain quinoa or BW flours. Bread technological properties, total polyphenol content and in vitro antioxidant activity and starch hydrolysis and dialysability were assessed. Specific bread volumes were between 2.61 and 2.76 cm3 g−1. Breads with quinoa-based SD had overall higher technological quality than breads made with BW SDs, shown by a softer, well-aerated crumb, with an opener crumb structure and larger air area. Crumb firming during storage was reduced up to 29% when quinoa SD was used, and up to 42% when BW SD was added. Quinoa breads showed higher polyphenols and FRAP values, whereas BW breads had significantly higher ABTS values. Total starch hydrolysis and dialysability were significantly reduced when SD was used. Starch hydrolysis was reduced up to 42% and 25% when quinoa and BW SD were used, respectively. SD application produced breads with higher technological quality and modified in vitro starch hydrolysis and antioxidant capacity. Even though these effects seemed to be influenced by pH, a biological effect was also observed. 相似文献