Search results for "Distributed"
showing 10 items of 1260 documents
Privacy-Preserving Overgrid: Secure Data Collection for the Smart Grid
2020
In this paper, we present a privacy-preserving scheme for Overgrid, a fully distributed peer-to-peer (P2P) architecture designed to automatically control and implement distributed Demand Response (DR) schemes in a community of smart buildings with energy generation and storage capabilities. To monitor the power consumption of the buildings, while respecting the privacy of the users, we extend our previous Overgrid algorithms to provide privacy preserving data aggregation (PP-Overgrid). This new technique combines a distributed data aggregation scheme with the Secure Multi-Party Computation paradigm. First, we use the energy profiles of hundreds of buildings, classifying the amount of &ldquo
"Table 2" of "Production of charged pions, kaons and protons at large transverse momenta in pp and Pb-Pb collisions at sqrt(sNN) = 2.76 TeV"
2014
Invariant yields of identified kaons in central and peripheral Pb-Pb collisions, together with the unscaled pp reference yields.
DiDuSoNet: A P2P architecture for Ditributed Dunbar-based Social Networks,
2015
Online Social Networks (OSNs) are becoming more and more popular on the Web. Distributed Online Social Networks (DOSNs) are OSNs which do not exploit a central server for storing users data and enable users to have more control on their profile content, ensuring a higher level of privacy. In a DOSN there are some technical challenges to face. One of the most important challenges is the data availability problem when a user is offline. In this paper we propose DiDuSoNet, a novel P2P Distributed Online Social Network where users can exercise full access control on their data. Our system exploits trust relationships for providing a set of important social services, such as trustness, informati…
Fiber laser switched by a long period grating interferometer as an intra-cavity loss modulator
2010
Abstract In this paper we present an actively switched fiber laser with an all-fiber long-period grating-based interferometer used as an intra-cavity loss modulator. The modulator consists of two equal long-period gratings written sequentially in the same piece of a double-clad optical fiber. One of the gratings is fixed onto a piezoceramic cylinder producing fast modulation of the interferometer transmission spectrum. The laser demonstrates a stable regime of pulsed emission at repetition rates in the range of tens of kHz.
Q-switching of an all-fiber laser by acousto-optic modulation of a fiber Bragg grating.
2009
We report active Q-switching of an all-fiber laser using a Bragg grating based acousto-optic modulator. Q-switching is performed by modulating a fiber Bragg grating with an extensional acoustic wave. The acoustic wave modulates periodically the effective index profile of the FBG and changes its reflection features. This allows controlling the Q-factor of the cavity. Using 1 m of 300 ppm erbium-doped fiber and a maximum pump power of 180 mW, Q-switch pulses of 10 W of peak power and 82 ns wide were generated. The pulse repetition rate of the laser can be continuously varied from few Hz up to 62.5 kHz.
Fiber laser with combined feedback of core and cladding modes assisted by an intracavity long-period grating
2011
We present a fiber laser made in a single piece of conventional doped-core fiber that operates by combined feedback of the fundamental core mode LP((0,1)) and the high-order cladding mode LP((0,10)). The laser is an all-fiber structure that uses two fiber Bragg gratings and a long-period grating to select the modes circulating in the cavity; the laser emits at the coupling wavelength between the core mode LP((0,1)) and the counterpropagating cladding mode LP((0,10)) in the Bragg gratings. This work demonstrates the feasibility of high-order mode fiber lasers assisted by long-period gratings.
Q-switched all-fiber laser based on magnetostriction modulation of a Bragg grating
2009
We report an actively Q-switched all-fiber laser based on magnetostriction modulation of a Bragg grating. The laser employs a pair of Bragg gratings as reflective mirrors, one of which is bonded to a magnetostrictive element. Lengthening of the magnetostrictive element when a magnetic field is applied shifts the Bragg wavelength of the grating, allowing control of the Q-factor of the cavity and, thus, performing active Q-switching. The magnetostrictive modulator is small, compact and requires less than 300 mW electrical drive power. Using erbium-doped fiber and a maximum pump power of 120 mW, Q-switch pulses of more than 1 W peak power were obtained, with a pulse repetition rate that can be…
A parallel simulated annealing approach to the K shortest loopless paths problem
1997
The k shortest loopless paths problem is a significant combinatorial problem which arises in many contexts. When the size of the networks is very large the exact algorithms fail to find the best solution in a reasonable time. The aim of this paper is to suggest parallel efficient algorithms to obtain a good approximation of the solution to the k shortest loopless paths problem between two arbitrary nodes, when the network size is large. The heuristic used is known in literature as Simulated Annealing. Preliminary tests have been conducted for evaluating the validity of the proposed algorithms. The quality of the obtained results represents a significant base for further experimentations.
Parallel Schwarz methods for convection-dominated semilinear diffusion problems
2002
AbstractParallel two-level Schwarz methods are proposed for the numerical solution of convection-diffusion problems, with the emphasis on convection-dominated problems. Two variants of the methodology are investigated. They differ from each other by the type of boundary conditions (Dirichlet- or Neumann-type) posed on a part of the second-level subdomain interfaces. Convergence properties of the two-level Schwarz methods are experimentally compared with those of a variant of the standard multi-domain Schwarz alternating method. Numerical experiments performed on a distributed memory multiprocessor computer illustrate parallel efficiency of the methods.
Classifier Optimized for Resource-constrained Pervasive Systems and Energy-efficiency
2017
Computational intelligence is often used in smart environment applications in order to determine a user’scontext. Many computational intelligence algorithms are complex and resource-consuming which can beproblematic for implementation devices such as FPGA:s, ASIC:s and low-level microcontrollers. Thesetypes of devices are, however, highly useful in pervasive and mobile computing due to their small size,energy-efficiency and ability to provide fast real-time responses. In this paper, we propose a classi-fier, CORPSE, specifically targeted for implementation in FPGA:s, ASIC:s or low-level microcontrollers.CORPSE has a small memory footprint, is computationally inexpensive, and is suitable for…