Search results for "Signal processing"
showing 10 items of 2451 documents
Optimization of trigeneration systems by Mathematical Programming: Influence of plant scheme and boundary conditions
2015
Abstract The large potential for energy saving by cogeneration and trigeneration in the building sector is scarcely exploited due to a number of obstacles in making the investments attractive. The analyst often encounters difficulties in identifying optimal design and operation strategies, since a number of factors, either endogenous (i.e. related with the energy load profiles) and exogenous (i.e. related with external conditions like energy prices and support mechanisms), influence the economic viability. In this paper a decision tool is adopted, which represents an upgrade of a software analyzed in previous papers; the tool simultaneously optimizes the plant lay-out, the sizes of the main…
Managing electrical energy storage systems and shiftable loads with an innovative approach in energy districts
2014
In this work, a power dispatch problem for a system composed of an aggregate of loads and an electrical energy storage system is considered. The approach to solve the optimal dispatch is innovative and shows good performances in limited calculation times. According to the more recent indications coming from the European distributors, the architecture for energy dispatch at distribution level will be hierarchical. The 'Aggregator' is the interface between groups of loads and the energy distributor and sends the individual consumers the desired load profiles, following which the user may gets a discount on the energy bill. On the other hand, the energy tariff may follow a given daily profile …
Analytical results forO(αs)radiative corrections toe+e−→tt¯↑up to a given gluon energy cut
2009
We determine the O({alpha}{sub s}) radiative corrections to polarized top quark pair production in e{sup +}e{sup -} annihilations with a specified gluon energy cut. We write down fully analytical results for the unpolarized and polarized O({alpha}{sub s}) cross sections e{sup +}e{sup -}{yields}tt(G) and e{sup +}e{sup -}{yields}tt{sup {up_arrow}}(G) including their polar orientation dependence relative to the beam direction. In the soft-gluon limit we recover the usual factorizing form known from the soft-gluon approximation. In the limit when the gluon energy cut takes its maximum value we recover the totally inclusive unpolarized and polarized cross sections calculated previously. We provi…
Efficient Simulation of Orthogonal Multicarrier Transmission over Multipath Fading Channels
2011
Filterbank orthogonal multicarrier transmission schemes, such as OFDM/OQAM, are currently under intense study for their spectral efficiency and suitability for the physical layer of Cognitive Radio. Nonetheless, the mathematical description of the signal is cumbersome, and closed form expressions for performance figures are not available, so performance analysis on fading channels has to be performed by means of simulations. We propose an algorithm for simulating the received signal over multipath frequency selective fading channels, based on Taylor series expansion of the channel transfer function. The proposed method is compared to the state-of-the-art FFT-based method in terms of computa…
Observation of s-Channel Production of Single Top Quarks at the Tevatron
2014
We report the first observation of single-top-quark production in the s channel through the combination of the CDF and D0 measurements of the cross section in proton-antiproton collisions at a center-of-mass energy of 1.96 TeV. The data correspond to total integrated luminosities of up to 9.7fb-1 per experiment. The measured cross section is σs=1.29-0.24+0.26pb. The probability of observing a statistical fluctuation of the background to a cross section of the observed size or larger is 1.8×10-10, corresponding to a significance of 6.3 standard deviations for the presence of an s-channel contribution to the production of single-top quarks. © 2014 American Physical Society.
White light sources filtered with fiber Bragg gratings for RF-photonics applications
2003
Abstract In this paper we demonstrate that broadband light emitters filtered with fiber Bragg gratings are a suitable light source for RF-photonics applications. A 0.075 nm bandwidth fiber grating illuminated by a light emitter of 40 nm bandwidth has been used as light source to feed a microwave phase shifter based on a chirped fiber Bragg grating. The device operates successfully in the tested frequency range (0.5–6) GHz and has been optically tuned in a range of 4 nm.
Overview and performance comparison of grid synchronization algorithms
2014
Distributed power generation units are experiencing an impressive growth. Consequently, the amount of energy injected by non-linear loads as power converters is expected to increase. Stability and quality of the overall grid are heavily affected by performances of grid-side converters. In this paper, an overview of grid-synchronization technique is proposed. The grid-side inverter is implemented in MATLAB/Simulink® environment including current control and grid-synchronization section. Both Synchronous Reference Frame (SRF) and Decoupled Double Synchronous Reference Frame (DDSRF) PLL algorithms are implemented. A performance comparison is carried out under ideal and unbalanced utility condi…
B-mode versus A-mode ultrasonographic measurements of mucosal thickness in vivo
2002
Abstract Objective: The objective of this study was to compare the measurement accuracy of A-mode and B-mode ultrasonographic assessments of palatal masticatory mucosal thickness in vivo. Study Design: Thickness of palatal masticatory mucosa in the molar region of 50 volunteers was measured once with a B-mode ultrasound device (10 MHz) combined with a standoff for intraoral applications. At identical reading points thickness was also assessed with an A-mode device (5 replicates) and by needle probing for determination of true thickness. Results: On average true thickness ranged between 2.9 and 3.3 mm (95% confidence intervals; median, 3.1 mm). B-mode ultrasonography overestimated truth by 0…
IDEA: interface dynamics and energetics algorithm.
2007
IDEA, interface dynamics and energetics algorithm, was implemented, in FORTRAN, under different operating systems to mimic dynamics and energetics of elementary events involved in interfacial processes. The code included a parallel elaboration scheme in which both the stochastic and the deterministic components, involved in the developed physical model, worked simultaneously. IDEA also embodied an optionally running VISUAL subroutine, showing the dynamic energy changes caused by the surface events, e.g., occurring at the gas-solid interface. Monte Carlo and ordinary differential equation system subroutines were employed in a synergistic way to drive the occurrence of the elementary events a…
Boundary-layer effects in wedges of piezoelectric laminates
2005
An approach to investigate boundary-layer effects in wedges of piezoelectric laminated structures is presented with the aim of ascertaining the electromechanical response characteristics. The wedge layer behavior is described in terms of generalized stress functions, which lead to a model consisting of a set of three coupled partial differential equations. The strength of the solution singularity is determined by solving the eigenvalue problem associated with the resolving system. The solution of the model is obtained by an eigenfunction expansion method coupled with a boundary collocation technique. Correspondingly, the singularity amplitude is assessed by introducing and calculating the g…