1,010 research outputs found
Estado actual de la técnica y cuestiones perdurables en la recogida de datos antropométricos
The study of human body size and shape has been a topic of research for a very long time. In the past, anthropometry used traditional measuring techniques to record the dimensions of the human body and reported variance in body dimensions as a function of mean and standard deviation. Nowadays, the study of human body dimensions can be carried out more efficiently using three-dimensional body scanners, which can provide large amounts of anthropometric data more quickly than traditional techniques can. This paper presents a description of the broad range of issues related to the collection of anthropometric data using three-dimensional body scanners, including the different types of technologies available and their implications, the standard scanning process needed for effective data collection, and the possible sources of measurement errors that might affect the reliability and validity of the data collected.El estudio del tamaño y la forma del cuerpo humano ha sido un tema de investigaciĂłn durante un tiempo muy largo. En el pasado, la antropometrĂa utilizĂł tĂ©cnicas de mediciĂłn tradicionales para registrar las dimensiones del cuerpo humano y reportĂł la variaciĂłn en las dimensiones del cuerpo en funciĂłn de la media y la desviaciĂłn estándar. Hoy en dĂa, el estudio de las dimensiones del cuerpo humano se puede llevar a cabo utilizando maneras más eficientes, como los escáneres tridimensionales del cuerpo, que pueden proporcionar grandes cantidades de datos antropomĂ©tricos más rápidamente que las tĂ©cnicas tradicionales. En este trabajo se presenta una descripciĂłn de la amplia gama de temas relacionados con la recogida de datos antropomĂ©tricos utilizando escáneres tridimensionales del cuerpo, incluyendo los diferentes tipos de tecnologĂas disponibles y sus implicaciones, el proceso de digitalizaciĂłn estándar necesario para la captura efectiva de datos, y las posibles fuentes de los errores de mediciĂłn que podrán afectar la fiabilidad y validez de los datos recogidos.This work is financed by FEDER funds through the Competitive Factors Operational Program (COMPETE) POCI-01-0145-FEDER-007043 and POCI-01-0145FEDER-007136 and by national funds through FCT – the Portuguese Foundation for Science and Technology, under the projects UID/CEC/00319/2013 and UID/CTM/00264 respectively
A validation study of a Kinect based Body Imaging (KBI) device system based on ISO 20685:2010
To replace the traditional anthropometric data collection processes with the 3D acquiring system it is
important that the validity of the data is not compromised. To do this, a validation study, based on the
guideline of ISO 20685, can be performed. This paper presents the results of a comparison between
traditional measurements and measurements taken with a 3D acquiring system using only four Kinect
sensors. The results obtained were then compared with the maximum allowable error indicated in ISO
20685, concluding that this system cannot give sufficiently reliable data that can substitute the manual
procedures.FEDER funds through the Competitive Factors Operational Program (COMPETE) and by national funds through FCT (Portuguese Foundation for Science and Technology) with the projects PEst- C/CTM/U10264 and ID/CEC/00319/201
Female firefighters’ body weight and stature: a comparison between two Portuguese fire brigades
Anthropometric data are essential for applying ergonomic principles to the design of a
wide range of products and are paramount when developing personal protective equipment. In the
case of occupations that deal with extreme circumstances, as is the case of firefighting, a proper fit
and sizing of personal protective equipment is related not only with work performance and comfort
but also with protection level. The increase in the number of female firefighters have raised the
discussion about the barriers and challenges faced by women in firefighting. Issues with the fit of
personal protective equipment commonly appear among physical and psychological stressors
encountered by female firefighters. The need to provide gender-specific protective equipment forsuch
professionals is highlighted by many studies. Furthermore, significant anthropometric differences
among specialized occupational groups have also been found. However, anthropometric databases on
firefighters are still very limited. Aiming to fulfill this shortcoming as well as to understand if
Portuguese firefighters’ protective equipment is adjusted to their anthropometrics, a study designated
as Size FF Portugal – Anthropometric Study of Portuguese Firefighters is currently underway. This
paper presents a preliminary comparison of anthropometric data of female firefighters from two
different fire brigades located in the North of Portugal. Stature and body weight measurements of 30
participants were analyzed using both descriptive and inferential statistics. Results show that there
were not statistically significant differences on the average stature nor on the average body weight of
female firefighters from both brigades. Moreover, significant differences were not found when
comparing their types of commitment for both considered measurements. However, the comparison
of stature data of female firefighters with two available anthropometric databases of the Portuguese
population presented statistically significant differences. These results corroborate similar research
and highlight the relevance of the on-going study. A discussion regarding the results is presented,
taking into consideration the current stage of the study and its limitations.The authors would like to express appreciation for the support of the 2C2T – Centre for Textile
Science and Technology of the University of Minho. This work is financed by FEDER funds through
the Competitive Factors Operational Program (COMPETE) POCI-01-0145-FEDER-007136, by
national funds through the FCT-Portuguese Foundation for Science and Technology under the project
UID/CTM/000264, by Fundo de Apoio Ă s VĂtimas dos IncĂŞndios de PedrĂłgĂŁo, and by ICC/Lavoro
Portuguese firefighters’ boots: obtaining user input for an ergonomic redesign
Firefighters are the first responders to a wide variety of situations which require them to perform an array of movements. Firefighters’ personal protective equipment is designed to protect against hazardous conditions and must allow the accomplishment of firefighting job tasks with maximum safety and minimal limitations. Fire boots are made to protect firefighters’ feet, ankles, and lower legs from high heat, slippery surfaces, standing water, punctures, cuts, abrasions, and so on. However, literature shows the impacts of fire boots on firefighters’ performance. This paper presents preliminary results of an ongoing study which main goal is to propose solutions for an Ergonomic redesign of personal protective equipment used by Portuguese firefighters. In order to obtain first insights, identifying firefighters’ perceptions and specific needs, a pilot study was conducted in a fire brigade located in the North of Portugal. For qualitative data collection, both an online survey and an in-person semi-structured interview were administered. The responses and specific considerations about the structural fire boots obtained from 49 firefighters who participated in the pilot study are described and discussed. Findings from this study allowed a better understanding of the main issues encountered by Portuguese firefighters in wearing their fire boots and provided valuable inputs for developing the next phases of the study.FEDER funds through the Competitive Factors Operational Program (COMPETE) POCI-01-0145-FEDER-007136 and by national funds through FCT-Portuguese Foundation for Science and Technology, under the project UID/CTM/000264
SANEPIC: A Map-Making Method for Timestream Data From Large Arrays
We describe a map-making method which we have developed for the Balloon-borne
Large Aperture Submillimeter Telescope (BLAST) experiment, but which should
have general application to data from other submillimeter arrays. Our method
uses a Maximum Likelihood based approach, with several approximations, which
allows images to be constructed using large amounts of data with fairly modest
computer memory and processing requirements. This new approach, Signal And
Noise Estimation Procedure Including Correlations (SANEPIC), builds upon
several previous methods, but focuses specifically on the regime where there is
a large number of detectors sampling the same map of the sky, and explicitly
allowing for the the possibility of strong correlations between the detector
timestreams. We provide real and simulated examples of how well this method
performs compared with more simplistic map-makers based on filtering. We
discuss two separate implementations of SANEPIC: a brute-force approach, in
which the inverse pixel-pixel covariance matrix is computed; and an iterative
approach, which is much more efficient for large maps. SANEPIC has been
successfully used to produce maps using data from the 2005 BLAST flight.Comment: 27 Pages, 15 figures; Submitted to the Astrophysical Journal; related
results available at http://blastexperiment.info/ [the BLAST Webpage
Fast and precise map-making for massively multi-detector CMB experiments
Future cosmic microwave background (CMB) polarisation experiments aim to
measure an unprecedentedly small signal - the primordial gravity wave component
of the polarisation field B-mode. To achieve this, they will analyse huge
datasets, involving years worth of time-ordered data (TOD) from massively
multi-detector focal planes. This creates the need for fast and precise methods
to complement the M-L approach in analysis pipelines. In this paper, we
investigate fast map-making methods as applied to long duration, massively
multi-detector, ground-based experiments, in the context of the search for
B-modes. We focus on two alternative map-making approaches: destriping and TOD
filtering, comparing their performance on simulated multi-detector polarisation
data. We have written an optimised, parallel destriping code, the DEStriping
CARTographer DESCART, that is generalised for massive focal planes, including
the potential effect of cross-correlated TOD 1/f noise. We also determine the
scaling of computing time for destriping as applied to a simulated full-season
data-set for a realistic experiment. We find that destriping can out-perform
filtering in estimating both the large-scale E and B-mode angular power
spectra. In particular, filtering can produce significant spurious B-mode power
via EB mixing. Whilst this can be removed, it contributes to the variance of
B-mode bandpower estimates at scales near the primordial B-mode peak. For the
experimental configuration we simulate, this has an effect on the possible
detection significance for primordial B-modes. Destriping is a viable
alternative fast method to the full M-L approach that does not cause the
problems associated with filtering, and is flexible enough to fit into both M-L
and Monte-Carlo pseudo-Cl pipelines.Comment: 16 pages, 14 figures. MNRAS accepted. Typos corrected and computing
time/memory requirement orders-of-magnitude numbers in section 4 replaced by
precise number
Harmonic analysis of cosmic microwave background data I: ring reductions and point-source catalogue
We present a harmonic model for the data analysis of an all-sky cosmic
microwave background survey, such as Planck, where the survey is obtained
through ring-scans of the sky. In this model, resampling and pixelisation of
the data are avoided. The spherical transforms of the sky at each frequency, in
total intensity and polarization, as well as the bright-point-source catalogue,
are derived directly from the data reduced onto the rings. Formal errors and
the most significant correlation coefficients for the spherical transforms of
the frequency maps are preserved. A clean and transparent path from the
original samplings in the time domain to the final scientific products is thus
obtained. The data analysis is largely based on Fourier analysis of rings; the
positional stability of the instrument's spin axis during these scans is a
requirement for the data model and is investigated here for the Planck
satellite. Brighter point sources are recognised and extracted as part of the
ring reductions and, on the basis of accumulated data, used to build a
catalogue. The analysis of the rings is performed iteratively, involving a
range of geometric and detector response calibrations. The reconstructed
spherical transforms of the sky form the input to the subsequent analysis
stages. Although the methods in this paper were developed with the data
processing for Planck in mind, many aspects should have wider application, such
as in the construction of real-space pixelised maps. (Abridged)Comment: 20 pages, 9 figures. To appear in MNRA
The pre-launch Planck Sky Model: a model of sky emission at submillimetre to centimetre wavelengths
We present the Planck Sky Model (PSM), a parametric model for the generation
of all-sky, few arcminute resolution maps of sky emission at submillimetre to
centimetre wavelengths, in both intensity and polarisation. Several options are
implemented to model the cosmic microwave background, Galactic diffuse emission
(synchrotron, free-free, thermal and spinning dust, CO lines), Galactic H-II
regions, extragalactic radio sources, dusty galaxies, and thermal and kinetic
Sunyaev-Zeldovich signals from clusters of galaxies. Each component is
simulated by means of educated interpolations/extrapolations of data sets
available at the time of the launch of the Planck mission, complemented by
state-of-the-art models of the emission. Distinctive features of the
simulations are: spatially varying spectral properties of synchrotron and dust;
different spectral parameters for each point source; modeling of the clustering
properties of extragalactic sources and of the power spectrum of fluctuations
in the cosmic infrared background. The PSM enables the production of random
realizations of the sky emission, constrained to match observational data
within their uncertainties, and is implemented in a software package that is
regularly updated with incoming information from observations. The model is
expected to serve as a useful tool for optimizing planned microwave and
sub-millimetre surveys and to test data processing and analysis pipelines. It
is, in particular, used for the development and validation of data analysis
pipelines within the planck collaboration. A version of the software that can
be used for simulating the observations for a variety of experiments is made
available on a dedicated website.Comment: 35 pages, 31 figure
A Semantic Framework for Enabling Radio Spectrum Policy Management and Evaluation
Because radio spectrum is a finite resource, its usage and sharing is
regulated by government agencies. These agencies define policies to manage
spectrum allocation and assignment across multiple organizations, systems, and
devices. With more portions of the radio spectrum being licensed for commercial
use, the importance of providing an increased level of automation when
evaluating such policies becomes crucial for the efficiency and efficacy of
spectrum management. We introduce our Dynamic Spectrum Access Policy Framework
for supporting the United States government's mission to enable both federal
and non-federal entities to compatibly utilize available spectrum. The DSA
Policy Framework acts as a machine-readable policy repository providing policy
management features and spectrum access request evaluation. The framework
utilizes a novel policy representation using OWL and PROV-O along with a
domain-specific reasoning implementation that mixes GeoSPARQL, OWL reasoning,
and knowledge graph traversal to evaluate incoming spectrum access requests and
explain how applicable policies were used. The framework is currently being
used to support live, over-the-air field exercises involving a diverse set of
federal and commercial radios, as a component of a prototype spectrum
management system
All-sky convolution for polarimetry experiments
We discuss all-sky convolution of the instrument beam with the sky signal in
polarimetry experiments, such as the Planck mission which will map the
temperature anisotropy and polarization of the cosmic microwave background
(CMB). To account properly for stray light (from e.g. the galaxy, sun, and
planets) in the far side-lobes of such an experiment, it is necessary to
perform the beam convolution over the full sky. We discuss this process in
multipole space for an arbitrary beam response, fully including the effects of
beam asymmetry and cross-polarization. The form of the convolution in multipole
space is such that the Wandelt-Gorski fast technique for all-sky convolution of
scalar signals (e.g. temperature) can be applied with little modification. We
further show that for the special case of a pure co-polarized, axisymmetric
beam the effect of the convolution can be described by spin-weighted window
functions. In the limits of a small angle beam and large Legendre multipoles,
the spin-weight 2 window function for the linear polarization reduces to the
usual scalar window function used in previous analyses of beam effects in CMB
polarimetry experiments. While we focus on the example of polarimetry
experiments in the context of CMB studies, we emphasise that the formalism we
develop is applicable to anisotropic filtering of arbitrary tensor fields on
the sphere.Comment: 8 pages, 1 figure; Minor changes to match version accepted by Phys.
Rev.
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