Search results for "signal processing"
showing 10 items of 2451 documents
More restrictive Gray codes for necklaces and Lyndon words
2008
In the last years, the order induced by the Binary Reflected Gray Code or its generalizations shown an increasing interest. In this note we show that the BRGC order induces a cyclic 2-Gray code on the set of binary necklaces and Lyndon words and a cyclic 3-Gray code on the unordered counterparts. This is an improvement and a generalization to unlabeled words of the result in [V. Vajnovszki, Gray code order for Lyndon words, Discrete Math. Theoret. Comput. Sci. 9 (2) (2007) 145-152; M. Weston, V. Vajnovszki, Gray codes for necklaces and Lyndon words of arbitrary base, Pure Mathematics and Applications/Algebra and Theoretical Computer Science, in press]; however an algorithmic implementation …
TLMCO-simulation for an open source MPSOC platform under STARSoC environment
2008
In the last decade, the embedded systems become more and more complex. This complexity is due to the fact that these systems contain more heterogeneous hardware and software components (CPUpsilas, DSP, IP, etc.). Such systems called multiprocessor-on-chip (MPSoC) require new design approaches in order to satisfy several constraints, verification time, cost and time to market.
Toward Unified Control of Networks of Switches and Sensors Through a Network Operating System
2018
Wireless sensor networks (WSNs) are an integral part of an Internet of Things (IoT) ecosystem. In fact, a typical IoT service deployment considers an integrated network of switches and sensors (as well as actuators). In order to manage this heterogeneous network infrastructure, the use of software defined networking (SDN) technologies is anticipated. However, existing SDN-enabling technologies consider only isolated networks and there has been no concrete solution that treats the whole network in a unified way. In this paper, a network operating system is proposed as a way to address the above issue. Starting from the open network operating system, which currently supports only OpenFlow net…
Improved primary regulation for minimum energy losses in islanded microgrids
2017
In this paper, an improved primary regulation is proposed for grid forming units supplying islanded microgrids. A minimum losses Optimal Power Flow is run off-line to devise the operating set points composing the primary regulation curve. In this way, after load perturbations, generators can reach an optimized operating point for a given and unique minimum losses energy flows distribution. The idea is to skip the hierarchical control architecture and provide a feasible and optimized operating point. A case study over 24 hours shows the effectiveness of this new approach as well as the improved operation quality of the system.
<title>Optical sensing for early cardiovascular diagnostics</title>
2000
A sensor device for noninvasive detection and analysis of the pulsating blood flow waveforms by means of the reflective single-period photoplethysmorgraphy (SPPPG) technique has been designed and clinically tested. The sensor is operated jointly with any standard PC, by connecting the sensor head to the AD-card and using a separate hard disc with the signal processing software; all circuits are fed by the PC power supply. After processing, normalized shape of the mean SPPPG signal and its parameters are calculated and displayed; the measurement/processing time does not exceed 2 minutes. The clinically detected SPPPG signal shapes and corresponding parameters are presented and discussed. The…
Experimental evidence of Brillouin-induced polarization wheeling in highly birefringent optical fibers
2009
International audience; We study the influence of Stimulated Brillouin Scattering on the polarization stabilization of a light beam propagating in a highly-birefringent optical fiber. In particular, due to a saturation effect, we find that the output polarization lies on a ring when the polarization is represented onto the Poincaré sphere.
Generation of localized pulses from incoherent wave in optical fiber lines made of concatenated Mamyshev regenerators
2008
International audience; We investigate the novel properties of optical fiber lines made of Mamyshev regenerators (MRs) based on self-phase modulation and subsequent spectral filtering. In particular, we show that such a regenerator line can be used to generate random sequences of optical pulses from an incoherent wave. This behavior is related to the existence of stable eigenpulses that can propagate unchanged through the regenerator line and act as attractors for incoming pulses. By changing the regenerator parameters, we also report the existence of multiple eigenpulses and limit cycles. Finally, we demonstrate that MRs could be used as efficient nonlinear gates in fiber laser cavities.
On-chip quantum optical frequency comb sources
2018
Integrated optical frequency comb sources, based on nonlinear microring resonators, can be used to generate complex quantum states. In particular, we achieved multi-photon and high-dimensional entangled quantum states, as well as their coherent control.
Highly efficient few-mode spatial beam self-cleaning at 15µm
2020
We experimentally demonstrate that spatial beam self-cleaning can be highly efficient when obtained with a few-mode excitation in graded-index multimode optical fibers. By using 160 ps long, highly chirped (6 nm bandwidth at -3dB) optical pulses at 1562 nm, we demonstrate a one-decade reduction of the power threshold for spatial beam self-cleaning, with respect to previous experiments using pulses with laser wavelengths at 1030-1064 nm. Self-cleaned beams remain spatio-temporally stable for more than a decade of their peak power variation. The impact of input pulse temporal duration is also studied.
Coupling between counterpropagating cladding modes in fiber Bragg gratings
2011
We present an experimental demonstration of energy transfer between counterpropagating cladding modes in a fiber Bragg grating (FBG). A strong FBG written in a standard photosensitive optical fiber is illuminated with a single cladding mode, and the power transferred between the forward propagating cladding mode and different backward propagating cladding modes is measured by using two auxiliary long period gratings. Resonances between cladding modes having 30 pm bandwidth and 8 dB rejection have been observed.