2,760 research outputs found
A State Observer Design for Simultaneous Estimation of Charge State and Crossover in Self-Discharging Disproportionation Redox Flow Batteries
This paper presents an augmented state observer design for the simultaneous
estimation of charge state and crossover flux in disproportionation redox flow
batteries, which exhibits exponential estimation error convergence to a bounded
residual set. The crossover flux of vanadium through the porous separator is
considered as an unknown function of the battery states, model-approximated as
the output of a persistently excited linear system. This parametric model and
the simple isothermal lumped parameter model of the battery are combined to
form an augmented space state representation suitable for the observer design,
which is carried out via Lyapunov stability theory including the
error-uncertainty involved in the approximation of the crossover flux. The
observer gain is calculated by solving a polytopic linear matrix inequality
problem via convex optimization. The performance of this design is evaluated
with a laboratory flow battery prototype undergoing self-discharge.Comment: arXiv admin note: text overlap with arXiv:1903.0407
SU(2) Lattice Gauge Theory Simulations on Fermi GPUs
In this work we explore the performance of CUDA in quenched lattice SU(2)
simulations. CUDA, NVIDIA Compute Unified Device Architecture, is a hardware
and software architecture developed by NVIDIA for computing on the GPU. We
present an analysis and performance comparison between the GPU and CPU in
single and double precision. Analyses with multiple GPUs and two different
architectures (G200 and Fermi architectures) are also presented. In order to
obtain a high performance, the code must be optimized for the GPU architecture,
i.e., an implementation that exploits the memory hierarchy of the CUDA
programming model.
We produce codes for the Monte Carlo generation of SU(2) lattice gauge
configurations, for the mean plaquette, for the Polyakov Loop at finite T and
for the Wilson loop. We also present results for the potential using many
configurations () without smearing and almost configurations
with APE smearing. With two Fermi GPUs we have achieved an excellent
performance of the speed over one CPU, in single precision, around
110 Gflops/s. We also find that, using the Fermi architecture, double precision
computations for the static quark-antiquark potential are not much slower (less
than slower) than single precision computations.Comment: 20 pages, 11 figures, 3 tables, accepted in Journal of Computational
Physic
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Monitoring and modeling of household air quality related to use of different Cookfuels in Paraguay.
In Paraguay, 49% of the population depends on biomass (wood and charcoal) for cooking. Residential biomass burning is a major source of fine particulate matter (PM2.5 ) and carbon monoxide (CO) in and around the household environment. In July 2016, cross-sectional household air pollution sampling was conducted in 80 households in rural Paraguay. Time-integrated samples (24 hours) of PM2.5 and continuous CO concentrations were measured in kitchens that used wood, charcoal, liquefied petroleum gas (LPG), or electricity to cook. Qualitative and quantitative household-level variables were captured using questionnaires. The average PM2.5 concentration (μg/m3 ) was higher in kitchens that burned wood (741.7 ± 546.4) and charcoal (107.0 ± 68.6) than in kitchens where LPG (52.3 ± 18.9) or electricity (52.0 ± 14.8) was used. Likewise, the average CO concentration (ppm) was higher in kitchens that used wood (19.4 ± 12.6) and charcoal (7.6 ± 6.5) than in those that used LPG (0.5 ± 0.6) or electricity (0.4 ± 0.6). Multivariable linear regression was conducted to generate predictive models for indoor PM2.5 and CO concentrations (predicted R2 = 0.837 and 0.822, respectively). This study provides baseline indoor air quality data for Paraguay and presents a multivariate statistical approach that could be used in future research and intervention programs
Melodic expectations in 5- and 6-year-old children
It has been argued that children implicitly acquire the rules relating to the structure of music in their environment using domain-general mechanisms such as statistical learning. Closely linked to statistical learning is the ability to form expectations about future events. Whether children as young as 5 years can make use of such internalized regularities to form expectations about the next note in a melody is still unclear. The possible effect of the home musical environment on the strength of musical expectations has also been under-explored. Using a newly developed melodic priming task that included melodies with either “expected” or “unexpected” endings according to rules of Western music theory, we tested 5- and 6-year-old children (N = 46). The stimuli in this task were constructed using the information dynamics of music (IDyOM) system, a probabilistic model estimating the level of “unexpectedness” of a note given the preceding context. Results showed that responses to expected versus unexpected tones were faster and more accurate, indicating that children have already formed robust melodic expectations at 5 years of age. Aspects of the home musical environment significantly predicted the strength of melodic expectations, suggesting that implicit musical learning may be influenced by the quantity of informal exposure to the surrounding musical environment
Melodic expectations in 5- and 6-year-old children
It has been argued that children implicitly acquire the rules relating to the structure of music in their environment using domain-general mechanisms such as statistical learning. Closely linked to statistical learning is the ability to form expectations about future events. Whether children as young as 5 years can make use of such internalized regularities to form expectations about the next note in a melody is still unclear. The possible effect of the home musical environment on the strength of musical expectations has also been under-explored. Using a newly developed melodic priming task that included melodies with either “expected” or “unexpected” endings according to rules of Western music theory, we tested 5- and 6-year-old children (N = 46). The stimuli in this task were constructed using the information dynamics of music (IDyOM) system, a probabilistic model estimating the level of “unexpectedness” of a note given the preceding context. Results showed that responses to expected versus unexpected tones were faster and more accurate, indicating that children have already formed robust melodic expectations at 5 years of age. Aspects of the home musical environment significantly predicted the strength of melodic expectations, suggesting that implicit musical learning may be influenced by the quantity of informal exposure to the surrounding musical environment
The Wigner caustic on shell and singularities of odd functions
We study the Wigner caustic on shell of a Lagrangian submanifold L of affine
symplectic space. We present the physical motivation for studying singularities
of the Wigner caustic on shell and present its mathematical definition in terms
of a generating family. Because such a generating family is an odd deformation
of an odd function, we study simple singularities in the category of odd
functions and their odd versal deformations, applying these results to classify
the singularities of the Wigner caustic on shell, interpreting these
singularities in terms of the local geometry of L.Comment: 24 page
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Determination of Basic Structure-Property Relations for Processing and Modeling in Advanced Nuclear Fuel: Microstructure Evolution and Mechanical Properties
The project objective is to study structure-property relations in solid solutions of nitrides and oxides with surrogate elements to simulate the behavior of fuels of inert matrix fuels of interest to the Advanced Fuel Cycle Initiative (AFCI), with emphasis in zirconium-based materials. Work with actual fuels will be carried out in parallel in collaboration with Los Alamos National Laboratory (LANL). Three key aspects will be explored: microstructure characterization through measurement of global texture evolution and local crystallographic variations using Electron Backscattering Diffraction (EBSD); determination of mechanical properties, including fracture toughness, quasi-static compression strength, and hardness, as functions of load and temperature, and, finally, development of structure-property relations to describe mechanical behavior of the fuels based on experimental data. Materials tested will be characterized to identify the mechanisms of deformation and fracture and their relationship to microstructure and its evolution. New aspects of this research are the inclusion of crystallographic information into the evaluation of fuel performance and the incorporation of statistical variations of microstructural variables into simplified models of mechanical behavior of fuels that account explicitly for these variations. The work is expected to provide insight into processing conditions leading to better fuel performance and structural reliability during manufacturing and service, as well as providing a simplified testing model for future fuel production
Whole exome and targeted deep sequencing identify genome-wide allelic loss and frequent SETDB1 mutations in malignant pleural mesotheliomas.
Malignant pleural mesothelioma (MPM), a rare malignancy with a poor prognosis, is mainly caused by exposure to asbestos or other organic fibers, but the underlying genetic mechanism is not fully understood. Genetic alterations and causes for multiple primary cancer development including MPM are unknown. We used whole exome sequencing to identify somatic mutations in a patient with MPM and two additional primary cancers who had no evidence of venous, arterial, lymphovascular, or perineural invasion indicating dissemination of a primary lung cancer to the pleura. We found that the MPM had R282W, a key TP53 mutation, and genome-wide allelic loss or loss of heterozygosity, a distinct genomic alteration not previously described in MPM. We identified frequent inactivating SETDB1 mutations in this patient and in 68 additional MPM patients (mutation frequency: 10%, 7/69) by targeted deep sequencing. Our observations suggest the possibility of a new genetic mechanism in the development of either MPM or multiple primary cancers. The frequent SETDB1 inactivating mutations suggest there could be new diagnostic or therapeutic options for MPM
Real-time auditory feedback may reduce abnormal movements in patients with chronic stroke
Purpose
The current pilot study assesses the use of real-time auditory feedback to help reduce abnormal movements during an active reaching task in patients with chronic stroke.
Materials and methods
20 patients with chronic stroke completed the study with full datasets (age: M = 53 SD = 14; sex: male = 75%; time since stroke in months: M = 34, SD = 33). Patients undertook 100 repetitions of an active reaching task while listening to self-selected music which automatically muted when abnormal movement was detected, determined by thresholds set by clinical therapists. A within-subject design with two conditions (with auditory feedback vs. without auditory feedback) presented in a randomised counterbalanced order was used. The dependent variable was the duration of abnormal movement as a proportion of trial duration.
Results
A significant reduction in the duration of abnormal movement was observed when patients received auditory feedback, F(1,18) = 9.424, p = 0.007, with a large effect size (partial η2 = 0.344).
Conclusions
Patients with chronic stroke can make use of real-time auditory feedback to increase the proportion of time they spend in optimal movement patterns. The approach provides a motivating framework that encourages high dose with a key focus on quality of movement
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