1,416 research outputs found
A new approach to texture coding using stochastic vector quantization
A new method for texture coding which combines 2-D linear prediction and stochastic vector quantization is presented in this paper. To encode a texture, a linear predictor is computed first. Next, a codebook following the prediction error model is generated and the prediction error is encoded with VQ, using an algorithm which takes into account the pixels surrounding the block being encoded. In the decoder, the error image is decoded first and then filtered as a whole, using the prediction filter. Hence, correlation between pixels is not lost from one block to another and a good reproduction quality can be achieved.Peer ReviewedPostprint (published version
A Novel Use of Light Guides and Wavelength Shifting Plates for the Detection of Scintillation Photons in Large Liquid Argon Detectors
Scintillation light generated as charged particles traverse large liquid
argon detectors adds valuable information to studies of weakly-interacting
particles. This paper uses both laboratory measurements and cosmic ray data
from the Blanche dewar facility at Fermilab to characterize the efficiency of
the photon detector technology developed at Indiana University for the single
phase far detector of DUNE. The efficiency of this technology was found to be
0.48% at the readout end when the detector components were characterized with
laboratory measurements. A second determination of the efficiency using cosmic
ray tracks is in reasonable agreement with the laboratory determination. The
agreement of these two efficiency determinations supports the result that
minimum ionizing muons generate photons/MeV as
they cross the LAr volume.Comment: Accepted version (without final editorial corrections
Extruded scintillator for the Calorimetry applications
An extrusion line has been installed and successfully operated at FNAL (Fermi National Accelerator
Laboratory) in collaboration with NICADD (Northern Illinois Center for Accelerator and Detector
Development). This new Facility will serve to further develop and improve extruded plastic scintillator.
Recently progress has been made in producing co-extruded plastic scintillator, thus increasing the
potential HEP applications of this Facility. The current R&D work with extruded and co-extruded
plastic scintillator for a potential ALICE upgrade, the ILC calorimetry program and the MINERvA
experiment show the attractiveness of the chosen strategy for future experiments and calorimetry. We
extensively discuss extruded and co-extruded plastic scintillator in calorimetry in synergy with new
Solid State Photomultipliers. The characteristics of extruded and co-extruded plastic scintillator will be
presented here as well as results with non-traditional photo read-ou
Detección de ruido en aprendizaje semisupervisado con el uso de flujos de datos
A menudo, es necesario construir conjuntos de entrenamiento. Si disponemos
solamente de un número reducido de objetos etiquetados y de un conjunto
numeroso de objetos no etiquetados, podemos construir el conjunto de
entrenamiento simulando un flujo de datos no etiquetados de los cuales es
necesario aprender para poder incorporarlos al conjunto de entrenamiento.
Con el objetivo de prevenir que se deterioren los conjuntos de entrenamiento
que se obtienen, en este trabajo se propone un esquema que tiene en cuenta
el concept drift, ya que en muchas situaciones la distribución de las clases
puede cambiar con el tiempo. Para clasificar los objetos no etiquetados hemos
empleado un ensemble de clasificadores y proponemos una estrategia para
detectar el ruidoOften, it is necessary to construct training sets. If we have only a small
number of tagged objects and a large group of unlabeled objects, we can build
the training set simulating a data stream of unlabelled objects from which it
is necessary to learn and to incorporate them to the training set later. In order
to prevent deterioration of the training set obtained, in this work we propose
a scheme that takes into account the concept drift, since in many situations the distribution of classes may change over time. To classify the unlabelled
objects we have used an ensemble of classifiers and we propose a strategy to
detect the noise after the classification proces
Reaching the quantum limit of sensitivity in electron spin resonance
We report pulsed electron-spin resonance (ESR) measurements on an ensemble of
Bismuth donors in Silicon cooled at 10mK in a dilution refrigerator. Using a
Josephson parametric microwave amplifier combined with high-quality factor
superconducting micro-resonators cooled at millikelvin temperatures, we improve
the state-of-the-art sensitivity of inductive ESR detection by nearly 4 orders
of magnitude. We demonstrate the detection of 1700 bismuth donor spins in
silicon within a single Hahn echo with unit signal-to-noise (SNR) ratio,
reduced to just 150 spins by averaging a single Carr-Purcell-Meiboom-Gill
sequence. This unprecedented sensitivity reaches the limit set by quantum
fluctuations of the electromagnetic field instead of thermal or technical
noise, which constitutes a novel regime for magnetic resonance.Comment: Main text : 10 pages, 4 figures. Supplementary text : 16 pages, 8
figure
Discrete models of dislocations and their motion in cubic crystals
A discrete model describing defects in crystal lattices and having the
standard linear anisotropic elasticity as its continuum limit is proposed. The
main ingredients entering the model are the elastic stiffness constants of the
material and a dimensionless periodic function that restores the translation
invariance of the crystal and influences the Peierls stress. Explicit
expressions are given for crystals with cubic symmetry: sc, fcc and bcc.
Numerical simulations of this model with conservative or damped dynamics
illustrate static and moving edge and screw dislocations and describe their
cores and profiles. Dislocation loops and dipoles are also numerically
observed. Cracks can be created and propagated by applying a sufficient load to
a dipole formed by two edge dislocations.Comment: 23 pages, 15 figures, to appear in Phys. Rev.
Nanoscale broadband transmission lines for spin qubit control
The intense interest in spin-based quantum information processing has caused
an increasing overlap between two traditionally distinct disciplines, such as
magnetic resonance and nanotechnology. In this work we discuss rigourous design
guidelines to integrate microwave circuits with charge-sensitive
nanostructures, and describe how to simulate such structures accurately and
efficiently. We present a new design for an on-chip, broadband, nanoscale
microwave line that optimizes the magnetic field driving a spin qubit, while
minimizing the disturbance on a nearby charge sensor. This new structure was
successfully employed in a single-spin qubit experiment, and shows that the
simulations accurately predict the magnetic field values even at frequencies as
high as 30 GHz.Comment: 18 pages, 8 figures, 1 table, pdflate
Modelling driving behaviour and its impact on the energy management problem in hybrid electric vehicles
Perfect knowledge of future driving conditions can be rarely assumed on real applications when optimally splitting power demands among different energy sources in a hybrid electric vehicle. Since performance of a control strategy in terms of fuel economy and pollutant emissions is strongly affected by vehicle power requirements, accurate predictions of future driving conditions are needed. This paper proposes different methods to model driving patterns with a stochastic approach. All the addressed methods are based on the statistical analysis of previous driving patterns to predict future driving conditions, some of them employing standard vehicle sensors, while others require non-conventional sensors (for instance, global positioning system or inertial reference system). The different modelling techniques to estimate future driving conditions are evaluated with real driving data and optimal control methods, trading off model complexity with performance.Guardiola García, C.; Plá Moreno, B.; Blanco Rodriguez, D.; Reig Bernad, A. (2014). Modelling driving behaviour and its impact on the energy management problem in hybrid electric vehicles. International Journal of Computer Mathematics. 91(1):147-156. doi:10.1080/00207160.2013.829567S147156911Ericsson, E. (2001). Independent driving pattern factors and their influence on fuel-use and exhaust emission factors. Transportation Research Part D: Transport and Environment, 6(5), 325-345. doi:10.1016/s1361-9209(01)00003-7Q. Gong, P. Tulpule, V. Marano, S. Midlam-Mohler, and G. Rizzoni,The role of ITS in PHEV performance improvement, 2011 American Control Conference, June–July, San Francisco, CA, 2011, pp. 2119–2124.C. Guardiola, B. Pla, S. Onori, and G. Rizzoni,A new approach to optimally tune the control strategy for hybrid vehicles applications, IFAC Workshop on Engine and Powertrain Control, Simulation and Modeling E-COSM’12, October, Rueil-Malmaison, France, 2012.Johannesson, L., Asbogard, M., & Egardt, B. (2007). Assessing the Potential of Predictive Control for Hybrid Vehicle Powertrains Using Stochastic Dynamic Programming. IEEE Transactions on Intelligent Transportation Systems, 8(1), 71-83. doi:10.1109/tits.2006.884887Liu, S., & Yao, B. (2008). Coordinate Control of Energy Saving Programmable Valves. IEEE Transactions on Control Systems Technology, 16(1), 34-45. doi:10.1109/tcst.2007.903073Paganelli, G. (2001). General supervisory control policy for the energy optimization of charge-sustaining hybrid electric vehicles. JSAE Review, 22(4), 511-518. doi:10.1016/s0389-4304(01)00138-2Rizzoni, G., Guzzella, L., & Baumann, B. M. (1999). Unified modeling of hybrid electric vehicle drivetrains. IEEE/ASME Transactions on Mechatronics, 4(3), 246-257. doi:10.1109/3516.789683Control of hybrid electric vehicles. (2007). IEEE Control Systems, 27(2), 60-70. doi:10.1109/mcs.2007.338280L. Serrao, S. Onori, and G. Rizzoni,ECMS as realization of Pontryagin's minimum principle for HEV control, 2009 American Control Conference, June, Saint Louis, MO, 2009, pp. 3964–3969.Serrao, L., Onori, S., & Rizzoni, G. (2011). A Comparative Analysis of Energy Management Strategies for Hybrid Electric Vehicles. Journal of Dynamic Systems, Measurement, and Control, 133(3). doi:10.1115/1.4003267Stockar, S., Marano, V., Canova, M., Rizzoni, G., & Guzzella, L. (2011). Energy-Optimal Control of Plug-in Hybrid Electric Vehicles for Real-World Driving Cycles. IEEE Transactions on Vehicular Technology, 60(7), 2949-2962. doi:10.1109/tvt.2011.2158565Sundström, O., Ambühl, D., & Guzzella, L. (2009). On Implementation of Dynamic Programming for Optimal Control Problems with Final State Constraints. Oil & Gas Science and Technology – Revue de l’Institut Français du Pétrole, 65(1), 91-102. doi:10.2516/ogst/2009020O. Sundström and L. Guzzella,A generic dynamic programming Matlab function, 18th IEEE International Conference on Control Applications Part of 2009 IEEE Multi-conference on Systems and Control, July, Saint Petersburg, 2009, pp. 1625–1630.R. Wang and S.M. Lukic,Review of driving conditions prediction and driving style recognition based control algorithms for hybrid electric vehicles, Vehicle Power and Propulsion Conference (VPPC), 2011 IEEE, September 6–9, Raleigh, NC, 2011, pp. 1–7
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