Search results for "Control system"
showing 10 items of 971 documents
Hilbert–Schmidt speed as an efficient figure of merit for quantum estimation of phase encoded into the initial state of open n-qubit systems
2021
AbstractHilbert–Schmidt speed (HSS) is a special type of quantum statistical speed which is easily computable, since it does not require diagonalization of the system state. We find that, when both HSS and quantum Fisher information (QFI) are calculated with respect to the phase parameter encoded into the initial state of an n-qubit register, the zeros of the HSS dynamics are actually equal to those of the QFI dynamics. Moreover, the signs of the time-derivatives of both HSS and QFI exactly coincide. These findings, obtained via a thorough investigation of several paradigmatic open quantum systems, show that HSS and QFI exhibit the same qualitative time evolution. Therefore, HSS reveals its…
Dijets at Tevatron Cannot Constrain SMEFT Four-Quark Operators
2019
We explore the sensitivity of Tevatron data to heavy new physics effects in differential dijet production rates using the SMEFT in light of the fact that consistent and conservative constraints from the LHC cannot cover relatively low cutoff scales in the EFT. In contrast to the results quoted by the experimental collaborations and other groups, we find that, once consistency of the perturbation expansion is enforced and reasonable estimates of theoretical errors induced by the SMEFT series in $\frac{E}{\Lambda}$ are included, there is no potential to constrain four-quark contact interactions using Tevatron data. This shows the general difficulty of constraining physics model-independently …
Heavy quark parameters and |Vcb| from spectral moments in semileptonic B decays
2002
We extract the heavy quark masses and non-perturbative parameters from the Delphi preliminary measurements of the first three moments of the charged lepton energy and hadronic mass distributions in semileptonic B decays, using a multi-parameter fit. We adopt two formalisms, one of which does not rely on a 1/mc expansion and makes use of running quark masses. The data are consistent and the level of accuracy of the experimental inputs largely determines the present sensitivity. The results allow to improve on the uncertainty in the extraction of Vcb.
Constrained-Design of Passive UHF RFID Sensor Antennas
2013
Passive UHF RFID tags may be used, beside labeling, to remotely observe the physical/chemical change of the tagged object, through modulation of their impedance and gain, thus acting as sensor antennas. The design of this new class of devices can be mastered by fully understanding the relationship between communication and sensing with the purpose to balance the maximization of the dynamic range of the response with the stability of the read distance. A new kind of communication/sensing nomogram permits to display both behaviors in a unitary way and to predict their physical limits, as well as to formalize a multi-parameter general-purpose optimization methodology. The procedure is demonstr…
Human body sensing: A pervasive approach by implanted RFID tags
2011
Starting from the physical evidence that passive RFID systems may be used as self-sensing devices, the feasibility of human monitoring by means of implanted tags is here investigated. The key parameters to master with the purpose to enhance the sensitivity of the implanted radiosensor have been theoretically analyzed and numerically applied to a specific medical problem, i.e. the continuous monitoring of liver cancer evolution. Preliminary experimental results with simplified phantoms corroborate the analysis.
Passive UHF RFID antennas for sensing applications: Principles, methods, and classifcations
2013
UHF passive radio-frequency identification technology is rapidly evolving from simple labeling of things to wireless pervasive sensing. A remarkable number of scientific papers demonstrate that objects in principle can have their physical properties be remotely tracked and monitored all along their life cycle. The key background is a new paradigm of antenna design that merges together the conventional communication issues with more-specific requirements about sensitivity to time-varying boundary conditions. This paper presents a unified review of the state of the art of the tag-as-sensor problem. Particular care is taken to formalize the measurement indicators and the communication and sens…
EFFICIENT MACHINE LEARNING FRAMEWORK FOR COMPUTER-AIDED DETECTION OF CEREBRAL MICROBLEEDS USING THE RADON TRANSFORM
2014
International audience; Recent developments of susceptibility weighted MR techniques have improved visualization of venous vasculature and underlying pathologies such as cerebral microbleed (CMB). CMBs are small round hypointense lesions on MRI images that are emerging as a potential biomarker for cerebrovascular disease. CMB manual rating has limited reliability, is time-consuming and is prone to errors as small CMBs can be easily missed or mistaken for venous crosssections. This paper presents a computer-aided detection technique that utilizes a novel cascade of random forest classifiers which are trained on robust Radon-based features with an unbalanced sample distribution. The training …
Design of Radiation-Hardened Rare-Earth Doped Amplifiers through a Coupled Experiment/Simulation Approach
2013
International audience; We present an approach coupling a limited experimental number of tests with numerical simulations regarding the design of radiation-hardened (RH) rare earth (RE)-doped fiber amplifiers. Radiation tests are done on RE-doped fiber samples in order to measure and assess the values of the principal input parameters requested by the simulation tool based on particle swarm optimization (PSO) approach. The proposed simulation procedure is validated by comparing the calculation results with the measured degradations of two amplifiers made with standard and RH RE-doped optical fibers, respectively. After validation, the numerical code is used to theoretically investigate the …
Electrical distribution substation remote diagnosis and control system
2014
This paper presents the conception, design, set up and realization of a prototype system for telemanagement of a MV/LV substation. The prototype has been developed according to the current standards. This system allows to monitor the status of the MV/LV substation box, of the medium voltage equipment, of the transformer and of the low voltage equipment. In particular, the system acts when some specified events occur. The prototype has been realized by using a DAQ; the software that implement the telemanagement system has been developed in LabVIEW environment. The system allows a remote monitoring of the quantities of interest that is carried out using the TeamViewer software able to establi…
Controlling Domains with High Levels of Hysteresis Using Qualitative Modelling
1997
Abstract Dans ce papier, on se propose I'architecture d'un systeme expert pour controle a temps reel basee sur un modele qualitatif- Le susteme de controle utilise le modele qualitatif pour predire problemes futures et pour manier dounees incompletes et imprecises des sensors. Cettes habilites sout tres precieses pour controler systemes avec une grande niveau d'hysteresis, et foumissent un controle doux et rapide. Nous avans applique l'architecture proposee a le domaine du control de trafic urbain, caracterise par grandes problemes d'hysteresis.