1,477 research outputs found
Flexible Sensor Network Reprogramming for Logistics
Besides the currently realized applications, Wireless Sensor
Networks can be put to use in logistics processes. However, doing so requires a level of flexibility and safety not provided by the current WSN software platforms. This paper discusses a logistics scenario, and presents SensorScheme, a runtime environment used to realize this scenario, based on semantics of the Scheme programming language. SensorScheme is a general purpose WSN platform, providing dynamic reprogramming, memory safety (sandboxing), blocking I/O, marshalled communication, compact code transport. It improves on the state of the art by making better use of the little available memory, thereby providing greater capability in terms of program size and complexity. We illustrate the use of our platform with some application examples, and provide experimental results to show its
compactness, speed of operation and energy efficiency
Correlation dynamics in East Asian financial markets
We examine the dynamic relationship between stock returns and exchange rate changes using daily data from January 1994 to September 2013 for six East Asian countries. We use the multivariate GARCH-DCC model in order to disclose the relationship between stock markets and foreign exchange markets which is important for understanding financial stability. The estimation results reveal time varying correlations in the pre and post Asian crisis and the Global Financial Crisis periods for all countries. The correlations are stronger when the crisis intensifies. The degree of interdependence between both markets reflects a mutually markets response to shocks and changes in policy
Run-time Spatial Mapping of Streaming Applications to Heterogeneous Multi-Processor Systems
In this paper, we define the problem of spatial mapping. We present reasons why performing spatial mappings at run-time is both necessary and desirable. We propose what is—to our knowledge—the first attempt at a formal description of spatial mappings for the embedded real-time streaming application domain. Thereby, we introduce criteria for a qualitative comparison of these spatial mappings. As an illustration of how our formalization relates to practice, we relate our own spatial mapping algorithm to the formal model
Disability and all-cause mortality in the older population: evidence from the English Longitudinal Study of Ageing.
Despite the vast body of literature studying disability and mortality, evidence to support their association is scarce. This work investigates the role of disability in explaining all-cause mortality among individuals aged 50+ who participated in the English Longitudinal Study of Aging. The aim is to explain the gender paradox in health and mortality by analysing whether the association of disability with mortality differs between women and men. Disability was conceived following the International Classification of Functioning, Disability and Health (ICF), proposed by the WHO, that conceptualizes disability as a combination of three components: impairment, activity limitation and participation restriction. Latent variable models were used to identify domain-specific factors and general disability. The association of the latter with mortality up to 10 years after enrolment was estimated using discrete-time survival analysis. Our work confirms the validity of the ICF framework and finds that disability is strongly associated with mortality, with a time-varying effect among men, and a smaller constant effect for women. Adjusting for demographic, socioeconomic and behavioural factors attenuated the association for both sexes, but overall the effects remained high and significant. These findings confirm the existence of gender paradox by showing that, when affected by disability, women survive longer than men, although if men survive the first years they appear to become more resilient to disability. Sensitivity analyses suggested that the gender paradox cannot be solely explained by gender-specific health conditions: there must be other mechanisms acting within the pathway between disability and mortality that need to be explored
Correlation Dynamics in East Asian Financial Markets
This paper examines the dynamic relationship between stock returns and exchange rate changes using daily data from January 3, 1994 - September 27, 2013 for six East Asian countries: Indonesia, Malaysia, the Philippines, Singapore, South Korea and Thailand. We estimate conditional correlations using the multivariate GARCH-DCC model in order to disclose the relationship between stock markets and foreign exchange markets. This is important for understanding financial stability. The estimation results reveal time varying correlations in the pre and post Asian crisis and the Global Financial Crisis periods for all countries. The correlations are stronger when the crisis intensies. The degree of interdependence between both markets reflects a mutually markets response to shocks and changes in policy
Model ab initio study of charge carrier solvation and large polaron formation on conjugated carbon chains
Using long C_{N}H_{2} conjugated carbon chains with the polyynic structure as
prototypical examples of one-dimensional (1D) semiconductors, we discuss
self-localization of excess charge carriers into 1D large polarons in the
presence of the interaction with a surrounding polar solvent. The solvation
mechanism of self-trapping is different from the polaron formation due to
coupling with bond-length modulations of the underlying atomic lattice
well-known in conjugated polymers. Model ab initio computations employing the
hybrid B3LYP density functional in conjunction with the polarizable continuum
model are carried out demonstrating the formation of both electron- and
hole-polarons. Polarons can emerge entirely due to solvation but even larger
degrees of charge localization occur when accompanied by atomic displacements
Phonon Coherence and New Set of Sidebands in Phonon-Assisted Photoluminescence
We investigate excitonic polaron states comprising a local exciton and
phonons in the longitudinal optical (LO) mode by solving the Schr\"{o}dinger
equation. We derive an exact expression for the ground state (GS), which
includes multi-phonon components with coefficients satisfying the Huang-Rhys
factors. The recombination of GS and excited polaron states gives one set of
sidebands in photoluminescence (PL): the multi-phonon components in the GS
produce the Stokes lines and the zero-phonon components in the excited states
produce the anti-Stokes lines. By introducing the mixing of the LO mode and
environal phonon modes, the exciton will also couple with the latter, and the
resultant polaron states result in another set of phonon sidebands. This set
has a zero-phonon line higher and wider than that of the first set due to the
tremendous number of the environal modes. The energy spacing between the
zero-phonon lines of the first and second sets is proved to be the binding
energy of the GS state. The common exciton origin of these two sets can be
further verified by a characteristic Fano lineshape induced by the coherence in
the mixing of the LO and the environal modes.Comment: 5 pages, 3 figures 1 figure (fig. 1) replaced 1 figure (fig. 2)
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Endocrine correlates of male breast cancer risk: a case-control study in Athens, Greece
We studied the relation of certain endocrine-related variables among 23 cases of male breast cancer and 76 apparently healthy male controls. There were significant inverse associations with smoking (P = 0.03), birth order (P = 0.02) and reported frequency of orgasms in later life (P = 0.0004). The study provides strong indirect evidence that endocrine factors are important in the aetiology of male breast cancer. © 2000 Cancer Research Campaig
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