8,260 research outputs found
Access to Physician Services: Does Supplemental Insurance Matter? Evidence from France
In France, public health insurance is universal but incomplete, with private payments accounting for roughly 25 percent of all spending. As a result, most people have supplemental private health insurance. We investigate the effects of such insurance on the utilization of physician services using data from the 1998 Enquˆte Sant‚ Protection Sociale, a nationally representative survey of the French population. Our results indicate that insurance has a strong and significant effect on the utilization of physician services. Individuals with supplemental coverage have substantially more physician visits than those without. In a context where patients are free to choose their provider, we find no evidence that adults with supplemental insurance are more likely to visit a specialist than a general practitioner.
Eco: A Hardware-Software Co-Design for In Situ Power Measurement on Low-end IoT Systems
Energy-constrained sensor nodes can adaptively optimize their energy
consumption if a continuous measurement exists. This is of particular
importance in scenarios of high dynamics such as energy harvesting or adaptive
task scheduling. However, self-measuring of power consumption at reasonable
cost and complexity is unavailable as a generic system service. In this paper,
we present Eco, a hardware-software co-design enabling generic energy
management on IoT nodes. Eco is tailored to devices with limited resources and
thus targets most of the upcoming IoT scenarios. The proposed measurement
module combines commodity components with a common system interfaces to achieve
easy, flexible integration with various hardware platforms and the RIOT IoT
operating system. We thoroughly evaluate and compare accuracy and overhead. Our
findings indicate that our commodity design competes well with highly optimized
solutions, while being significantly more versatile. We employ Eco for energy
management on RIOT and validate its readiness for deployment in a five-week
field trial integrated with energy harvesting
FlexClock: Generic Clock Reconfiguration for Low-end IoT Devices
Clock configuration within constrained general-purpose microcontrollers takes
a key role in tuning performance, power consumption, and timing accuracy of
applications in the Internet of Things (IoT). Subsystems governing the
underlying clock tree must nonetheless cope with a huge parameter space,
complex dependencies, and dynamic constraints. Manufacturers expose the
underlying functions in very diverse ways, which leads to specialized
implementations of low portability. In this paper, we propose FlexClock, an
approach for generic online clock reconfiguration on constrained IoT devices.
We argue that (costly) generic clock configuration of general purpose computers
and powerful mobile devices need to slim down to the lower end of the device
spectrum. In search of a generalized solution, we identify recurring patterns
and building blocks, which we use to decompose clock trees into independent,
reusable components. With this segmentation we derive an abstract
representation of vendor-specific clock trees, which then can be dynamically
reconfigured at runtime. We evaluate our implementation on common hardware. Our
measurements demonstrate how FlexClock significantly improves peak power
consumption and energy efficiency by enabling dynamic voltage and frequency
scaling (DVFS) in a platform-agnostic way
Mesure des modules viscoélastiques d'un polypropylène lors d'un refroidissement et d'un changement de phase
International audienceLa rhéologie d'un polypropylène de grade injection a été mesurée sur un rhéomètre plan - plan lors d'un refroidissement depuis l'état fondu jusqu'au début de la solidification. Ce type de donnée est important en particulier lorsque l'on s'intéresse aux contraintes résiduelles prenant naissance à la solidification. Un outillage plan - plan rainuré a été monté sur un rhéomètre asservi en contrainte. Le rainurage limite le phénomène de glissement qui interviendrait sur un matériau solidifié. On a ainsi pu mesurer les températures de transition lors de la cristallisation. Un point de gel a pu être mis en évidence au début de la cristallisation pour des vitesses de refroidissement de 2°C par minute. Le dispositif a également pu être évalué dans le sens de la fusion du matériau solidifié. Des expériences complémentaires ont été conduites en calorimétrie pour valider les températures de transitions obtenues.Des vitesses de refroidissement plus élevées ont permis de mesurer l'évolution des modules en fonction des conditions de refroidissement = The rheology of an injection grade polypropylene was measured in a plate plate rheometer during cooling from the melt to the beginning of solidification. These results are particularly important when we are interested by the construction of residual stresses during solidification. A grooved tool was mounted on a tresscontrolled rheometer. The grooves limit the slippage which happened on a solid. We measured the transition temperature during crystallisation. A gel point is observed for a cooling rate of 2°C by minute. The fixture is also evaluated for melting. Differential Scanning Calorimetry was also used for validation of the transition temperatures. Higher cooling rates permitted the measurement of modulus versus cooling conditions
Color--Luminosity Relations for the Resolved Hot Stellar Populations in the Centers of M 31 and M 32
We present Faint Object Camera (FOC) ultraviolet images of the central
14x14'' of Messier 31 and Messier 32. The hot stellar population detected in
the composite UV spectra of these nearby galaxies is partially resolved into
individual stars, and their individual colors and apparent magnitudes are
measured. We detect 433 stars in M 31 and 138 stars in M 32, down to detection
limits of m_F275W = 25.5 mag and m_F175W = 24.5 mag. We investigate the
luminosity functions of the sources, their spatial distribution, their
color-magnitude diagrams, and their total integrated far-UV flux. Although M 32
has a weaker UV upturn than M 31, the luminosity functions and color-magnitude
diagrams of M 31 and M 32 are surprisingly similar, and are inconsistent with a
majority contribution from any of the following: PAGB stars more massive than
0.56 Msun, main sequence stars, or blue stragglers. Both the the luminosity
functions and color-magnitude diagrams are consistent with a dominant
population of stars that have evolved from the extreme horizontal branch (EHB)
along tracks with masses between 0.47 and 0.53 Msun. These stars are well below
the detection limits of our images while on the zero-age EHB, but become
detectable while in the more luminous (but shorter) AGB-Manque' and post-early
asymptotic giant branch (PEAGB) phases. The FOC observations require that only
a only a very small fraction of the main sequence population (2% in M 31 and
0.5% in M 32) in these two galaxies evolve though the EHB and post-EHB phases,
with the remainder evolving through bright PAGB evolution that is so rapid that
few if any stars are expected in the small field of view covered by the FOC.Comment: 35 pages, Latex. 19 figures. To appear in ApJ. Uses emulateapj.sty
and apjfonts.sty (included). Color plates distributed seperatedly: fig1.jpg
and fig2.jp
Transport and recombination through weakly coupled localized spin pairs in semiconductors during coherent spin excitation
Semi-analytical predictions for the transients of spin-dependent transport
and recombination rates through localized states in semiconductors during
coherent electron spin excitation are made for the case of weakly spin-coupled
charge carrier ensembles. The results show that the on-resonant Rabi frequency
of electrically or optically detected spin-oscillation doubles abruptly as the
strength of the resonant microwave field gamma B_1 exceeds the Larmor frequency
separation within the pair of charge carrier states between which the transport
or recombination transition takes place. For the case of a Larmor frequency
separation of the order of gamma B_1 and arbitrary excitation frequencies, the
charge carrier pairs exhibit four different nutation frequencies. From the
calculations, a simple set of equations for the prediction of these frequencies
is derived
Two Instruments for Measuring Distributions of Low-Energy Charged Particles in Space
Current estimates indicate that the bulk of interplanetary gas consists of protons with energies between 0 and 20 kev and concentrations of 1 to 105 particles/cu cm. Methods and instrumentation for measuring the energy and density distribution of such a gas are considered from the standpoint of suitability for space vehicle payloads. It is concluded that electrostatic analysis of the energy distribution can provide sufficient information in initial experiments. Both magnetic and electrostatic analyzers should eventually be used. Several instruments designed and constructed at the Ames Research Center for space plasma measurements, and the methods of calibration and data reduction are described. In particular, the instrument designed for operation on solar cell power has the following characteristics: weight, 1.1 pounds; size, 2 by 3 by 4 inches; and power consumption, 145 mw. The instrument is designed to yield information on the concentration, energy distribution, and the anisotropy of ion trajectories in the 0.2 to 20 kev range
Argument-predicate distance as a filter for enhancing precision in extracting predications on the genetic etiology of disease
BACKGROUND: Genomic functional information is valuable for biomedical research. However, such information frequently needs to be extracted from the scientific literature and structured in order to be exploited by automatic systems. Natural language processing is increasingly used for this purpose although it inherently involves errors. A postprocessing strategy that selects relations most likely to be correct is proposed and evaluated on the output of SemGen, a system that extracts semantic predications on the etiology of genetic diseases. Based on the number of intervening phrases between an argument and its predicate, we defined a heuristic strategy to filter the extracted semantic relations according to their likelihood of being correct. We also applied this strategy to relations identified with co-occurrence processing. Finally, we exploited postprocessed SemGen predications to investigate the genetic basis of Parkinson's disease. RESULTS: The filtering procedure for increased precision is based on the intuition that arguments which occur close to their predicate are easier to identify than those at a distance. For example, if gene-gene relations are filtered for arguments at a distance of 1 phrase from the predicate, precision increases from 41.95% (baseline) to 70.75%. Since this proximity filtering is based on syntactic structure, applying it to the results of co-occurrence processing is useful, but not as effective as when applied to the output of natural language processing. In an effort to exploit SemGen predications on the etiology of disease after increasing precision with postprocessing, a gene list was derived from extracted information enhanced with postprocessing filtering and was automatically annotated with GFINDer, a Web application that dynamically retrieves functional and phenotypic information from structured biomolecular resources. Two of the genes in this list are likely relevant to Parkinson's disease but are not associated with this disease in several important databases on genetic disorders. CONCLUSION: Information based on the proximity postprocessing method we suggest is of sufficient quality to be profitably used for subsequent applications aimed at uncovering new biomedical knowledge. Although proximity filtering is only marginally effective for enhancing the precision of relations extracted with co-occurrence processing, it is likely to benefit methods based, even partially, on syntactic structure, regardless of the relation
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