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Measuring mental workload with the NASA-TLX needs to examine each dimension rather than relying on the global score: An example with driving
No full textThe distinction between several components of mental workload is often made in the ergonomics literature. However, measurements used are often established from a global score, notably with several questionnaires that originally reflect several dimensions. The present study tested the effect of driving situation complexity, experience and subjective levels of tension and alertness on each dimension of the NASA-TLX questionnaire of workload, in order to highlight the potential influence of intrinsic, extraneous and germane load factors. The results showed that, in complex situation, mental, temporal and physical demand (load dimensions) increased, and that novice drivers presented high physical demand when subjective tension was low and low own performance. Moreover, increase of mental and physical demand increased effort. It thus appears essential to distinguish the different components of mental workload used in the NASA-TLX questionnair
Fractional Fick's law for the boundary driven exclusion process with long jumps
No full textInternational audienceA fractional Fick's law and fractional hydrostatics for the one dimensional exclusion process with long jumps in contact with infinite reservoirs at different densities on the left and on the right are derived
An Evolutionary Algorithm for Discovering Multi-Relational Association Rules in the Semantic Web
No full textInternational audienceIn the Semantic Web context, OWL ontologies represent the conceptualization of domains of interest while the corresponding assertional knowledge is given by RDF data referring to them. Because of its open, distributed, and collaborative nature, such knowledge can be incomplete, noisy, and sometimes inconsistent. By exploiting the evidence coming from the assertional data, we aim at discovering hidden knowledge patterns in the form of multi-relational association rules while taking advantage of the intensional knowledge available in ontological knowledge bases. An evolutionary search method applied to populated ontological knowledge bases is proposed for finding rules with a high inductive power. The proposed method, EDMAR, uses problem-aware genetic operators, echoing the refinement operators of ILP, and takes the intensional knowledge into account, which allows it to restrict and guide the search. Discovered rules are coded in SWRL, and as such they can be straightforwardly integrated within the ontology, thus enriching its expressive power and augmenting the assertional knowledge that can be derived. Additionally , discovered rules may also suggest new axioms to be added to the ontology. We performed experiments on publicly available ontologies, validating the performances of our approach and comparing them with the main state-of-the-art systems
Vowel purity and rhyme evidence in Old Chinese reconstruction
No full textInternational audienceRhyme patterns in Old Chinese poems are important for the reconstruction of Old Chinese pronunciation, as they provide evidence for groups of words which formerly had similar pronunciation. Rhyme patterns can also be used to test Old Chinese reconstruction systems for consistency and plausibility, as reconstruction systems should minimize the conflict with attested rhyme patterns. Here, we build on the idea that rhyming in Old Chinese followed the principle of vowel purity, a tendency to disallow rhymes of words with different vowels, to develop a quantitative test for reconstruction systems of Old Chinese. The test is illustrated by comparing seven different Old Chinese reconstruction systems and by showing that, although the systems differ regarding their degree of vowel purity, the principle seems to hold for Old Chinese rhyme data
Simplified approach for quantitative calculations of optical pumping
No full textInternational audienceWe present a simple and pedagogical method for quickly calculating optical pumping processes based on linearised population rate equations. The method can easily be implemented on mathematical software run on modest personal computers, and can be generalized to any number of concrete situations. We also show that the method is still simple with realistic experimental complications taken into account, such as high level degeneracy, impure light polarization, and an added external magnetic field. The method and the associated mathematical toolbox should be of value in advanced physics teaching, and can also facilitate the preparation of research tasks
États de Savoie, Églises et institutions religieuses des Réformes au Risorgimento
No full textInternational audienc
On a directed variation of the 1-2-3 and 1-2 Conjectures
No full textInternational audienceIn this paper, we consider the following question, which stands as a directed analogue of the well-known 1-2-3 Conjecture: Given any digraph D with no arc (u,v) verifying d+(u)=d-(v)=1, is it possible to weight the arcs of D with weights among {1,2 3} so that, for every arc (u,v) of D, the sum of incident weights outgoing from u is different from the sum of incident weights incoming to v? We answer positively to this question, and investigate digraphs for which even the weights among {1,2} are sufficient. In relation with the so-called 1-2 Conjecture, we also consider a total version of the problem, which we prove to be false. Our investigations turn to have interesting relations with open questions related to the 1-2-3 Conjecture
Convex optimization for the synthesis of matching filters
No full textInternational audienceIn this work we study a particular filter synthesis problem in order to minimize the reflection coefficient of the global system consisting of filter and antenna. The matching problem is formulated as an optimization problem involving the minimization of a pseudo hyperbolic distance and the solution to this problem using H∞ approach yields a lower bound for the matching criterion related to the computation of a matching filter, with prescribed finite degree, under selectivity constraints