5,561 research outputs found
Fast Authentication in Heterogeneous Wireless Networks
The growing diffusion of wireless devices is leading to an increasing demand for mobility and security. At the same time, most applications can only tolerate short breaks in the data flow, so that it is a challenge to find out mobility and authentication methods able to cope with these constraints. This paper aims to propose an authentication scheme which significantly shortens the authentication latency and that can be deployed in a variety of wireless environments ranging from common Wireless LANs (WLANs) to satellite-based access networks
An Authentication and Key Establishment Scheme for the IP-Based Wireless Sensor Networks
Integration between wireless sensor networks and traditional IP networks using the IPv6 and 6LoWPAN standards is a very active research and application area. A combination of hybrid network significantly increases the complexity of addressing connectivity and fault tolerance problems in a highly heterogeneous environment, including for example different packet sizes in different networks. In such challenging conditions, securing the communication between nodes with very diverse computational, memory and energy storage resources is at the same time an essential requirement and a very complex issue. In this paper we present an efficient and secure mutual authentication and key establishment protocol based on Elliptic Curve Cryptography (ECC) by which different classes of nodes, with very different capabilities, can authenticate each other and establish a secret key for secure communication. The analysis of the proposed scheme shows that it provides good network connectivity and resilience against some well known attacks
Fast Authentication in Heterogeneous Wireless Networks
The growing diffusion of wireless devices is
leading to an increasing demand for mobility and security.
At the same time, most applications can only tolerate short
breaks in the data flow, so that it is a challenge to find out
mobility and authentication methods able to cope with these
constraints. This paper aims to propose an authentication
scheme which significantly shortens the authentication
latency and that can be deployed in a variety of wireless
environments ranging from common Wireless LANs
(WLANs) to satellite-based access networks
MOON: a New Overlay Network Architecture for Mobility and QoS Support
The continuously increasing diffusion of mobile devices
such as laptops, PDAs and smartphones, all equipped with
enhanced functionalities, has led to numerous studies about
mobility and to the definition of new network architectures
capable to support it.
Problems related to mobility have been addressed mostly
operating on the network or transport layers of the Internet
protocol stack. As a result, most of these solutions generally
require modifying the TCP and/or the IP protocol. Although this
approach is well suited to handle mobility, it lacks in
compatibility with the Internet Protocol Suite.
This consideration led us to study a fully TCP compatible and
flexible approach we dubbed MOON, for MObile Overlay
Network. This network architecture is currently under design at
LIPAR, the Internet, Protocols and Network Architecture Lab of
Politecnico di Torino
Calibration and performance tests of the Very-Front-End electronics for the CMS electromagnetic calorimeter
The Very-Front-End electronics processing signals from photodetectors of the CMS electromagnetic calorimeter have been put through an extensive test programme to guarantee functionality and reliability. The final characteristics of the VFE boards designed for the calorimeter barrel and endcaps are presented. The results, which have been also verified during test beam at CERN, confirm the high quality of the boards production and show that the CMS detector specifications are reached
Performance of a Tungsten-Cerium Fluoride Sampling Calorimeter in High-Energy Electron Beam Tests
A prototype for a sampling calorimeter made out of cerium fluoride crystals
interleaved with tungsten plates, and read out by wavelength-shifting fibres,
has been exposed to beams of electrons with energies between 20 and 150 GeV,
produced by the CERN Super Proton Synchrotron accelerator complex. The
performance of the prototype is presented and compared to that of a Geant4
simulation of the apparatus. Particular emphasis is given to the response
uniformity across the channel front face, and to the prototype's energy
resolution.Comment: 6 pages, 6 figures, Submitted to NIM
Multi physics modelling for a hybrid rocket engine with liquefying fuel: a sensitivity analysis on combustion instability
Hybrid rocket engines represent a promising alternative to both solid rocket motors and liquid rocket engines. They have throttling and restart capabilities with performance similar to storable liquids, but are safer and are low-cost. However, some drawbacks, such as low regression
rate and combustion instability, are limiting their effective application. Paraffin-based fuels are a solution envisaged to face the low regression rate issue, and the capability to describe and predict combustion instability in the presence of liquefying fuels becomes an enabling step towards the application of hybrid rockets in next-generation space launchers.
In this work, a multi physics model for hybrid rocket engines is presented and discussed. The model is based on a network of submodels, in which the chamber gas dynamics is described by a quasi-1D Euler model for reacting flows while thermal diffusion in the grain is described by the 1D heat equation in the radial direction. The need to introduce strong modelling simplifications introduces a significant uncertainty in the predictive capability of the numerical simulation. For this reason, a sensitivity analysis is performed in order to identify the key parameters which have the largest influence on combustion instability. Results are presented on a test case which refers to a paraffin-based grain burnt with hydrogen peroxide
Crilin: A CRystal calorImeter with Longitudinal InformatioN for a future Muon Collider
The measurement of physics processes at new energy frontier experiments
requires excellent spatial, time, and energy resolutions to resolve the
structure of collimated high-energy jets. In a future Muon Collider, the
beam-induced backgrounds (BIB) represent the main challenge in the design of
the detectors and of the event reconstruction algorithms. The technology and
the design of the calorimeters should be chosen to reduce the effect of the
BIB, while keeping good physics performance. Several requirements can be
inferred: i) high granularity to reduce the overlap of BIB particles in the
same calorimeter cell; ii) excellent timing (of the order of 100 ps) to reduce
the out-of-time component of the BIB; iii) longitudinal segmentation to
distinguish the signal showers from the fake showers produced by the BIB; iv)
good energy resolution (less than 10%/sqrt(E)) to obtain good physics
performance, as has been already demonstrated for conceptual particle flow
calorimeters. Our proposal consists of a semi-homogeneous electromagnetic
calorimeter based on Lead Fluoride Crystals (PbF2) readout by surface-mount
UV-extended Silicon Photomultipliers (SiPMs): the Crilin calorimeter. In this
paper, the performances of the Crilin calorimeter in the Muon Collider
framework for hadron jets reconstruction have been analyzed. We report the
single components characterizations together with the development of a
small-scale prototype, consisting of 2 layers of 3x3 crystals each
E835 at FNAL: Charmonium Spectroscopy in Annihilations
I present preliminary results on the search for in its
and decay modes. We observe an excess of \eta_c\gamma{\cal P} \sim 0.001M=3525.8 \pm 0.2 \pm 0.2
\Gamma\leq10.6\pm 3.7\pm3.4(br) <
\Gamma_{\bar{p}p}B_{\eta_c\gamma} < 12.8\pm 4.8\pm4.5(br) J/\psi\pi^0$ mode.Comment: Presented at the 6th International Conference on Hyperons, Charm and
Beauty Hadrons (BEACH 2004), Chicago(Il), June 27-July 3,200
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