15,351 research outputs found
mmWave V2V Localization in MU-MIMO Hybrid Beamforming
Recent trends for vehicular localization in millimetre-wave (mmWave) channels include employing a combination of parameters such as angle of arrival (AOA), angle of departure (AOD), and time of arrival (TOA) of the transmitted/received signals. These parameters are challenging to estimate, which along with the scattering and random nature of mmWave channels, and vehicle mobility lead to errors in localization. To circumvent these challenges, this paper proposes mmWave vehicular localization employing difference of arrival for time and frequency, with multiuser (MU) multiple-input-multiple-output (MIMO) hybrid beamforming; rather than relying on AOD/AOA/TOA estimates. The vehicular localization can exploit the number of vehicles present, as an increase in a number of vehicles reduces the Cramr-Rao bound (CRB) of error estimation. At 10 dB signal-to-noise ratio (SNR) both spatial multiplexing and beamforming result in comparable localization errors. At lower SNR values, spatial multiplexing leads to larger errors compared to beamforming due to formation of spurious peaks in the cross ambiguity function. Accuracy of the estimated parameters is improved by employing an extended Kalman filter leading to a root mean square (RMS) localization error of approximately 6.3 meters
Spatially and Spectrally Resolved Observations of a Zebra Pattern in Solar Decimetric Radio Burst
We present the first interferometric observation of a zebra-pattern radio
burst with simultaneous high spectral (~ 1 MHz) and high time (20 ms)
resolution. The Frequency-Agile Solar Radiotelescope (FASR) Subsystem Testbed
(FST) and the Owens Valley Solar Array (OVSA) were used in parallel to observe
the X1.5 flare on 14 December 2006. By using OVSA to calibrate the FST the
source position of the zebra pattern can be located on the solar disk. With the
help of multi-wavelength observations and a nonlinear force-free field (NLFFF)
extrapolation, the zebra source is explored in relation to the magnetic field
configuration. New constraints are placed on the source size and position as a
function of frequency and time. We conclude that the zebra burst is consistent
with a double-plasma resonance (DPR) model in which the radio emission occurs
in resonance layers where the upper hybrid frequency is harmonically related to
the electron cyclotron frequency in a coronal magnetic loop.Comment: Accepted for publication in Ap
Cost of preventing workplace heat-related illness through worker breaks and the benefit of climate-change mitigation
The exposure of workers to hot environments is expected to increase as a result of climate change. In order to prevent heat-related illness, it is recommended that workers take breaks during working hours. However, this would lead to reductions in worktime and labor productivity. In this study, we estimate the economic cost of heat-related illness prevention through worker breaks associated with climate change under a wide range of climatic and socioeconomic conditions. We calculate the worktime reduction based on the recommendation of work/rest ratio and the estimated future wet bulb glove temperature, which is an index of heat stresses. Corresponding GDP losses (cost of heat-related illness prevention through worker breaks) are estimated using a computable general equilibrium model throughout this century. Under the highest emission scenario, GDP losses in 2100 will range from 2.6 to 4.0% compared to the current climate conditions. On the other hand, GDP losses will be less than 0.5% if the 2.0 °C goal is achieved. The benefit of climate-change mitigation for avoiding worktime loss is comparable to the cost of mitigation (cost of the greenhouse gas emission reduction) under the 2.0 °C goal. The relationship between the cost of heat-related illness prevention through worker breaks and global average temperature rise is approximately linear, and the difference in economic loss between the 1.5 °C goal and the 2.0 °C goal is expected to be approximately 0.3% of global GDP in 2100. Although climate mitigation and socioeconomic development can limit the vulnerable regions and sectors, particularly in developing countries, outdoor work is still expected to be affected. The effectiveness of some adaptation measures such as additional installation of air conditioning devices or shifting the time of day for working are also suggested. In order to reduce the economic impacts, adaptation measures should also be implemented as well as pursing ambitious climate change mitigation targets
Differential-difference system related to toroidal Lie algebra
We present a novel differential-difference system in (2+1)-dimensional
space-time (one discrete, two continuum), arisen from the Bogoyavlensky's
(2+1)-dimensional KdV hierarchy. Our method is based on the bilinear identity
of the hierarchy, which is related to the vertex operator representation of the
toroidal Lie algebra \sl_2^{tor}.Comment: 10 pages, 4 figures, pLaTeX2e, uses amsmath, amssymb, amsthm,
graphic
Lowering and raising operators for the free Meixner class of orthogonal polynomials
We compare some properties of the lowering and raising operators for the
classical and free classes of Meixner polynomials on the real line
Comunidade de pesquisa global: ¿o que os padrões internacionais de coautoria dizem sobre sua estrutura?
Global research community represents a noteworthy object for sociological studies. In this paper we regards it as an entity with network structure and try to analyze the current state of this structure and its recent dynamics. Among the many various approaches to studying the network links that bring together the researchers all over the world, we choose to look at the structure of international co-authorship of research papers published in journals indexed by Scopus Elsevier database. We try to provide a general outline of the network structure, to reveal distinct regional clusters existing at the various levels of this structure, and to discover whatever significant changes took place in the network structure over the last 25 years.La comunidad de investigación global representa un objeto notable para los estudios sociológicos. En este documento, lo consideramos como una entidad con estructura de red e intentamos analizar el estado actual de esta estructura y su dinámica reciente. Entre los diversos enfoques para estudiar los enlaces de red que reúnen a los investigadores de todo el mundo, elegimos observar la estructura de la coautoría internacional de los trabajos de investigación publicados en revistas indexadas por la base de datos Scopus Elsevier. Intentamos proporcionar una descripción general de la estructura de la red, revelar los distintos grupos regionales que existen en los distintos niveles de esta estructura y descubrir los cambios significativos que tuvieron lugar en la estructura de la red durante los últimos 25 años.A comunidade global de pesquisa representa um objeto notável para os estudos sociológicos. Neste trabalho nós o consideramos como uma entidade com estrutura de rede e tentamos analisar o estado atual dessa estrutura e sua dinâmica recente. Entre as várias abordagens para o estudo dos links de rede que reúnem pesquisadores de todo o mundo, optamos por analisar a estrutura de coautoria internacional de trabalhos de pesquisa publicados em periódicos indexados pela base de dados Scopus Elsevier. Tentamos fornecer um esboço geral da estrutura da rede, revelar clusters regionais distintos existentes nos vários níveis dessa estrutura e descobrir as mudanças significativas ocorridas na estrutura da rede nos últimos 25 anos
Functional association of idiotypic and I-J determinants on the antigen receptor of suppressor T cells.
European Paediatric Formulation Initiative (EuPFI)-Formulating Ideas for Better Medicines for Children.
© American Association of Pharmaceutical Scientists 2016, published by Springer US, available online at doi: https://doi.org/10.1208/s12249-016-0584-1The European Paediatric Formulation Initiative (EuPFI), founded in 2007, aims to promote and facilitate the preparation of better and safe medicines for children through linking research and information dissemination. It brings together the capabilities of the industry, academics, hospitals, and regulators within a common platform in order to scope the solid understanding of the major issues, which will underpin the progress towards the future of paediatric medicines we want.The EuPFI was formed in parallel to the adoption of regulations within the EU and USA and has served as a community that drives research and dissemination through publications and the organisation of annual conferences. The membership and reach of this group have grown since its inception in 2007 and continue to develop and evolve to meet the continuing needs and ambitions of research into and development of age appropriate medicines. Five diverse workstreams (age-appropriate medicines, Biopharmaceutics, Administration Devices, Excipients and Taste Assessment & Taste Masking (TATM)) direct specific workpackages on behalf of the EuPFI. Furthermore, EuPFI interacts with multiple diverse professional groups across the globe to ensure efficient working in the area of paediatric medicines. Strong commitment and active involvement of all EuPFI stakeholders have proved to be vital to effectively address knowledge gaps related to paediatric medicines, discuss potential areas for further research and identify issues that need more attention and analysis in the future.Peer reviewedFinal Accepted Versio
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