1,428 research outputs found
On the Assessment of Fitness to Drive: Steering and Brake Operative Forces
The Directive (EU) 2015/653 aimed at facilitating that the maximum force that any disabled driver could make on the vehicle's primary controls could be adjusted to their needs. The technical adjustment in the vehicle's design requires a measurement of the operational forces applied by the driver on the steering and brake controls, in order to determine its functional capacity during the execution of driving manoeuvres. The objective of this paper is to define the steering and braking operative forces used for driving current-market M1 motor vehicles for the fitness to drive assessment of drivers with physical disabilities. A total of 200 trials were performed with 17 different vehicles and 26 drivers. The results obtained help to define a new threshold's criteria for operative forces onto the steering and braking systems for adapting motor vehicles to disabled drivers. The main contribution of this paper consist on a new technical recommendations about the use of code 20.07 -braking- and 40.01 -steering- to be used in the fitness to drive assessment of driver with disabilities according to Directive (EU) 2015/653 requirements
Las Ilustraciones en la enseñanza-aprendizaje de las ciencias : análisis de libros de texto
Este trabajo centra su atención en la importancia que poseen las ilustraciones que utilizan los libros de texto de ciencias para la comprensión de su contenido. Para ello se parte de una fundamentación teórica en cuanto a los requisitos que deberían cumplir aquéllas para favorecer su adecuado procesamiento, así como la diferente morfología que suelen presentar en los libros de texto. A continuación se aborda un proceso de diseño y validación de una taxonomía para la categorización de las ilustraciones, la cual fue aplicada a los temas de mecánica de una muestra representativa de siete libros de educación secundaria obligatoria y a tres previos. Tras este análisis se discuten los resultados y se extraen unas conclusiones tendentes a la mejora en el uso de las ilustraciones.This paper focuses on how important the illustrations in science textbooks can be for understanding their content. To that end we start from a theoretical base of the requirements that those illustrations should accomplish to favour their appropriate processing, as well as from the different morphology that they normally show in textbooks. Then we approach a process of design and validation of a taxonomy to categorize the illustrations that was applied to the subject of Mechanics on a representative sample of seven textbooks of Obligatory Secondary Education (ESO) and three books from a system previous to ESO. After this analysis we discuss the results and draw conclusions aimed at improving the use of illustrations
Ultradiscrete kinks with supersonic speed in a layered crystal with realistic potentials
We develop a dynamical model of the propagating nonlinear localized
excitations, supersonic kinks, in the cation layer in a silicate mica crystal.
We start from purely electrostatic Coulomb interaction and add the
Ziegler-Biersack-Littmark short-range repulsive potential and the periodic
potential produced by other atoms of the lattice. This approach allows the
construction of supersonic kinks which can propagate in the lattice within a
large range of energies and velocities. The interparticle distances in the
lattice kinks with high energy are physically reasonable values. The
introduction of the periodic lattice potential results in the important feature
that the kinks propagate with a single velocity and a single energy which are
independent on the excitation conditions. The found kinks are ultra-discrete
and can be described with the "magic wave number" , which was
previously revealed in the nonlinear sinusoidal waves and supersonic kinks in
the Fermi-Pasta-Ulam lattice. The extreme discreteness of the supersonic kinks,
with basically two particles moving at the same time, allows the interpretation
of their double-kink structure. The energy of the supersonic kinks is between
the possible source of K recoil in beta decay and the energy necessary
for the ejection of an atom at the border as has been found experimentally.Comment: 14 pages, 15 figure
Aplicación del análisis secuencial al estudio del texto escrito e ilustraciones de los libros de física y química de la ESO
There is enough evidence for the significant weight that textbooks have nowdays in the science classroom, as a knowledge source of and as a means for teaching. In this paper a tool --sequential analysis-- to search the teaching sequence of textbooks and the role of illustrations in such a sequence is described and applied. For that purpose a sample of Secondary level Physics and Chemistry textbooks was selected. The results lead to make clear the didactic profile of revised textbooks and their grouping in two classes, one connected with a more traditional conception on teaching-learning of Science and another connected with a more modern conception in relation with the Spanish Educational Reform
Ant colony optimized planning for unmanned surface marine vehicles
This paper presents some results achieved from a preliminary study on the use
of the Ant Colony Algorithm to plan feasible optimal or suboptimal trajectories
for an autonomous ship manoeuvring. The scenario, for this preliminary work,
comprises only open sea manoeuvres. The goal involves obtaining the least
time consuming ship trajectory between to points, departing from the start
point with arbitrary initial speed and attitude values and arriving to the end
point with predefined speed and attitude values.
The specific dynamic of the ship imposes typical restrictions to its manoeuvrability.
In the present case, the non-holonomicity, the rate speed/turn radius,
and the imposed forward-only propulsion of the ship make up the main restrictions
to the ship movement. For long distances, the problem could be tackled
as a classical navigation problem, in which, for the most part of the ship
trajectory, techniques such inertial navigation should be enough. The problem
arises at short distances when it becomes a manoeuvring problem. In this case
to obtain a optimal, --in some cases just a feasible--, trajectory could be a difficult
problem.Peer Reviewe
Comparison of Brucella canis genomes isolated from different countries shows multiple variable regions
RESUMEN: Brucella canis is a pathogenic bacterium for dogs and its zoonotic potential has been increasing in recent years.In this study, we report the sequencing, annotation and analysis of the genome of Brucella canis strain Oliveri isolated from a dog in a breeding kennel in Medellín, Colombia, South America. Whole genome shotgun sequencing was carried out using the ROCHE 454 GS FLX Titanium technology at the National Center for Genomic Sequencing—CNSG in Medellin, Colombia. The assembly procedure was performed using Newbler v2.6. In the genome annotation process, each contig was analyzed independently using as reference Brucella suis ATCC 1330 chromosomes. This new genome could be useful for the development of diagnostic tools and for vaccines search as well, in order to reduce the health impact of this infection in both, dogs and humans. The sequence was deposited in EMBL-EBI with accession numbers HG803175 and HG803176 for chromosomes 1 and 2, respectively
Interpersonal perceptions of adverse peer experiences in first-grade students
Aim: The aim of this study was to identify which adverse peer experiences better predict perceived negative peer relationships among elementary school first graders according to sex. The peer experiences examined were peer rejection, peer victimization, and mutual antipathy; the interpersonal perceptions studied were perceived peer victimization, dyadic meta-perception of peer disliking, and loneliness.
Methods: The participants were 809 children (Mage = 6.4 years, SD = 0.32; ngirls = 412, 50.9%) enrolled in 35 first-grade classes from 15 schools in 4 Spanish regions: Valencia, n = 276, 34.1%; Balearic Islands, n = 140, 17.3%; Andalusia, n = 199, 24.6%; Castile-Leon, n = 194, 24%. We calculated sex differences in peer experiences and interpersonal perceptions by means of one-way ANOVA for means differences and Fisher’s r-to-z transformation for correlations differences. We used a multilevel regression analysis (nesting variables: class and region) to determine whether the associations between each peer experiences and each perception were unique.
Results: Each adverse peer relationship predicted each interpersonal perception differentially. Peer victimization was a good predictor of the three interpersonal perceptions, and the only predictor of perceived peer victimization. Peer rejection predicted loneliness, whereas mutual antipathies predicted dyadic meta-perception of peer disliking, although more so among girls. A significant effect at region level was found but not at class level.
Conclusion: Our findings suggest that research should take into account the different levels of the social peer system when analyzing peer experiences within the classroom context. The study contributes to sensitize teachers about the greater responsiveness of 6-year-old girls to adverse peer experiences, and it could be useful for designing interventions that would help children oppose rejection and empower active bystanders to fight against peer mistreatment.Ministerio de Economía y Competitividad de España EDU2012-35930Universitat Jaume I P1-1A2012-0
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