1,440 research outputs found
Automatic reading of aeronautical meteorological messages
This paper describes the architecture developed to produce an automatic reader of aeronautical meteorological messages. An interlingua has been used and a whole process of natural language generation has been implemented. The system Festival has been used with a modified voice to read the messages generated. The presented system is able to translate the meteorological messages into a natural language text and read it
Random Forests and Networks Analysis
D. Wilson~\cite{[Wi]} in the 1990's described a simple and efficient
algorithm based on loop-erased random walks to sample uniform spanning trees
and more generally weighted trees or forests spanning a given graph. This
algorithm provides a powerful tool in analyzing structures on networks and
along this line of thinking, in recent works~\cite{AG1,AG2,ACGM1,ACGM2} we
focused on applications of spanning rooted forests on finite graphs. The
resulting main conclusions are reviewed in this paper by collecting related
theorems, algorithms, heuristics and numerical experiments. A first
foundational part on determinantal structures and efficient sampling procedures
is followed by four main applications: 1) a random-walk-based notion of
well-distributed points in a graph 2) how to describe metastable dynamics in
finite settings by means of Markov intertwining dualities 3) coarse graining
schemes for networks and associated processes 4) wavelets-like pyramidal
algorithms for graph signals.Comment: Survey pape
Is baseline aerobic fitness associated with illness and attrition rate in military training?
Background Respiratory illnesses are a leading cause of morbidity and medical discharge in the military. This study aimed to investigate the effects of baseline aerobic fitness on haematological, salivary and mood variables, and simultaneously, in a novel approach, to identify factors precipitating illness and attrition rate in recruits during military training.
Methods Thirty-five healthy male recruits from an Army Training Regiment undertaking 12 weeks of training were prospectively investigated. Their 2.4 km run time (RT) was used as a surrogate of baseline aerobic fitness. Saliva and venous blood samples were analysed for secretory IgA, full blood counts and cell cytokine production (interleukin (IL) 6 and IL-8), respectively. Each recruit completed questionnaires on mood profile, and gastrointestinal and upper respiratory tract symptoms (URTS).
Results Significant salivary and haematological perturbations were observed and coincided with increased duration of URTS/week and mood disturbance over this military training period. From Start to End: leucocyte count decreased by 28% ( p<0.001); neutrophil percentage (%) decreased by 13% (p<0.01); lymphocyte % increased by 17% (p<0.05); the neutrophil:lymphocyte ratio decreased by 22% (p<0.01); eosinophil% increased by 71% (p<0.01). From Start to Mid to End: monocyte% increased by 68% at Mid (p<0.01) but only by 30% at End (p<0.01); IL-6 increased by 39% at Mid (p<0.01) and a further 61% by End. The 2.4 km RT was significantly associated with URTS duration (p<0.01). In addition, a 1-min increase in 2.4 km RT increased a recruitâs risk 9.8-fold of developing URTS lasting, on average, 3.36 days/week. In recruits ranked with high-URTS duration their RT was 48 s slower (p<0.01) than those with low-URTS, and their attrition rate reached 45%.
Conclusions The least fit recruits may have found training more physically demanding as reflected in the higher URTS duration, which may have led to a high attrition rate from the Army. It is worth considering that baseline aerobic fitness might be an important factor in illness development and attrition rate in recruits during this type of military training
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Implications of moderate altitude training for sea level endurance in elite distance runners
Elite distance runners participated in one of
two studies designed to investigate the e ects of mod-
erate altitude training (inspiratory partial pressure of
oxygen »115±125 mmHg) on submaximal, maximal and
supramaximal exercise performance following return to
sea-level. Study 1 (New Mexico, USA) involved 14
subjects who were assigned to a 4-week altitude training
camp (1500±2000 m) whilst 9 performance-matched
subjects continued with an identical training programme
at sea-level (CON). Ten EXP subjects who trained at
1640 m and 19 CON subjects also participated in study 2
(Krugersdorp, South Africa). Selected metabolic and
cardiorespiratory parameters were determined with the
subjects at rest and during exercise 21 days prior to
(PRE) and 10 and 20 days following their return to sea-
level (POST). Whole blood lactate decreased by 23%
(P < 0.05 vs PRE) during submaximal exercise in the
EXP group only after 20 days at sea-level (study 1).
However, the lactate threshold and other measures of
running economy remained unchanged. Similarly, su-
pramaximal performance during a standardised track
session did not change. Study 2 demonstrated that
hypoxia per se did not alter performance. In contrast, in
the EXP group supramaximal running velocity de-
creased by 2% (P < 0.05) after 20 days at sea-level.
Both studies were characterised by a 50% increase in the
frequency of upper respiratory and gastrointestinal tract
infections during the altitude sojourns, and two male
subjects were diagnosed with infectious mononucleosis
following their return to sea-level (study 1). Group mean
plasma glutamine concentrations at rest decreased by
19% or 143 (74) lM (P < 0.001) after 3 weeks at alti-
tude, which may have been implicated in the increased
incidence of infectious illness
Tribological behavior of functionalized 1-2 layered graphene/uhmwpe composites
In this work we present the evaluation of pristine and functionalized graphene as
reinforcements for UHMWPE-based composites. These composites were
manufactured by physically blending graphene particles and medical grade
UHMWPE powder followed by a thermo-compression process. Mechanical behaviour
by means of uniaxial tension and biaxial load by small punch were carried out.
Friction coefficient and wear rate were measured. In some cases composites
enhanced stiffness and yield stress, although with loss of toughness. This
mechanical behaviour was recuperated after a thermal treatment. Small positive
changes were obtained with some graphene concentrations respect to the friction
coefficient. However, 20 % of reduction in wear rate was obtained when the
graphene was functionalized. In general these composites present a good trend to be
a potential alternative to the current highly crosslinked polyethylenes.We thank the Ministry of Science and Education of Spain by means of the projects
MAT2010-16175) and CONSOLIDER CSD2008-00023 (FUNCOAT) for financial
suppor
Effect of extrusion on the mechanical and rheological properties of a reinforced poly(lactic acid): Reprocessing and recycling of biobased materials
The aim of this research paper is to study the behaviour of a common used biopolymer (Poly(Lactic Acid) (PLA)) after several reprocesses and how two different types of additives (a melt strength enhancer and a nanoadditive) affect its mechanical and rheological properties. Systematic extraction of extrudate samples from a twin-screw compounder was done in order to study the effect in the properties of the reprocessed material. Detailed rheological tests on a capillary rheometer as well as mechanical studies on a universal tensile machine after preparation of injected specimens were carried out. Results evidenced that PLA and reinforced PLA materials can be reprocessed and recycled without a remarkable loss in their mechanical properties. Several processing restrictions and specific phenomena were identified and are explained in the present manuscript
A note about the t`Hooft`s ansatz for SU(N) real time guage theories
The t`Hooft's ansatz reduces the classical Yang--Mills theory to the
one. It is shown that in the frame of this ansatz the real-time
classical solutions for the arbitrary SU(N) gauge group is obtained by
embedding into SU(N). It is argued that this group
structure is the only possibility in the frame of the considered ansatz. New
explicit solutions for SU(3) and SU(5) gauge groups are shown
Study of the eightfold degeneracy with a standard -Beam and a Super-Beam facility
The study of the eightfold degeneracy at a neutrino complex that includes a
standard -Beam and a Super-Beam facility is presented for the first time
in this paper. The scenario where the neutrinos are sent toward a Megaton water
Cerenkov detector located at the Fr\'{e}jus laboratory (baseline 130 Km) is
exploited. The performance in terms of sensitivity for measuring the continuous
( and ) and discrete ( and
) oscillation parameters for the -Beam
and Super-Beam alone, and for their combination has been studied. A brief
review of the present uncertainties on the neutrino and antineutrino
cross-sections is also reported and their impact on the discovery potential
discussed
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