169 research outputs found
Conception et validation expĂ©rimentale dâun robot manipulateur 6 DDL actionnĂ© par des embrayages magnĂ©torhĂ©ologiques semi-dĂ©localisĂ©s
Lâutilisation de robots manipulateurs est un standard en industrie pour automatiser deschaĂźnes de production. Ces robots sont prĂ©cis, robustes et rapides. Pour atteindre leurperformance, ils sont conçus avec des actionneurs puissants et ils sont faits de piĂšces mas-sives. Lorsquâils sont en utilisation, ces robots doivent ĂȘtre placĂ©s dans une zone clĂŽturĂ©epuisquâils reprĂ©sentent un danger pour les travailleurs. Pour pallier ce problĂšme, lâindustriese tourne vers les robots collaboratifs. Ces robots normalisĂ©s sont conçus pour ĂȘtre sansdanger pour les utilisateurs ce qui permet une intĂ©gration facile et abordable. PlusieursstratĂ©gies comme lâutilisation dâalgorithmes de contrĂŽle et des designs mĂ©caniques sontutilisĂ©s pour rĂ©duire le danger dâun robot manipulateur pour un utilisateur.Ce mĂ©moire prĂ©sente un manipulateur de 6 degrĂ©s de libertĂ© (DDL) actionnĂ© par des em-brayages magnĂ©torhĂ©ologiques (MR) semi-dĂ©localisĂ©s. Le manipulateur a Ă©tĂ© conçu pouratteindre ou dĂ©passer les performances des bras robots collaboratifs commerciaux dans lebut de valider la capacitĂ© des actionneurs MR pour des applications en robotique colla-borative. Le manipulateur a Ă©tĂ© dimensionnĂ© pour avoir des spĂ©cifications similaires auxrobots collaboratifs UR5 et WAM. Les spĂ©cifications ont Ă©tĂ© validĂ©es par les mesures ex-pĂ©rimentales. Le manipulateur a une masse en mouvement de seulement 5.3 kg et il peutdĂ©placer une masse de 4.5 kg Ă 1 m/s avec une portĂ©e de 0.885 m. De plus, la bandepassante en force est au-dessus de 50 Hz et la friction des joints est de maximum 10 % ducouple maximum du joint. Aussi, le manipulateur est intrinsĂšquement sĂ©curitaire et tolĂ©-rant aux impacts. En somme, il est possible de dire quâun actionnement MR semi-dĂ©localisĂ©est une solution prometteuse pour la robotique collaborative, mais dâautres mesures ex-pĂ©rimentales avec le manipulateur sont nĂ©cessaires pour que la technologie MR atteigneson plein potentiel en robotique. En autre, il serait nĂ©cessaire de mesurer la capacitĂ© dumanipulateur Ă produire des murs virtuels, de mesurer la prĂ©cision du positionnement dumanipulateur et de mesurer lâĂ©nergie transmise par le bras au moment dâun impac
The bicomplex quantum Coulomb potential problem
Generalizations of the complex number system underlying the mathematical
formulation of quantum mechanics have been known for some time, but the use of
the commutative ring of bicomplex numbers for that purpose is relatively new.
This paper provides an analytical solution of the quantum Coulomb potential
problem formulated in terms of bicomplex numbers. We define the problem by
introducing a bicomplex hamiltonian operator and extending the canonical
commutation relations to the form [X_i,P_k] = i_1 hbar xi delta_{ik}, where xi
is a bicomplex number. Following Pauli's algebraic method, we find the
eigenvalues of the bicomplex hamiltonian. These eigenvalues are also obtained,
along with appropriate eigenfunctions, by solving the extension of
Schrodinger's time-independent differential equation. Examples of solutions are
displayed. There is an orthonormal system of solutions that belongs to a
bicomplex Hilbert space.Comment: Clarifications; some figures removed; version to appear in Can. J.
Phy
super KdV equation
We construct supersymmetric KdV equation as a hamiltonian flow on the
super Virasoro algebra. The KdV superfield, the hamiltonian
and the related Poisson structure are concisely formulated in
harmonic superspace. The most general hamiltonian is shown to necessarily
involve breaking parameters which are combined in a traceless rank 2
tensor. First nontrivial conserved charges of super KdV (of
dimensions 2 and 4) are found to exist if and only if the breaking
tensor is a bilinear of some vector with a fixed length proportional to
the inverse of the central charge of algebra. After the reduction
to this restricted version of super KdV goes over to the
integrable case of super KdV and so is expected to be integrable. We show
that it is bi-hamiltonian like its prototype.Comment: 11 pages, preprint ENSLAPP-L-415-9
A conceptual morphodynamic model including storm impacts for microtidal barred beaches
International audienceThis paper introduces the main results of a large dataset concerning the impacts of storm events and recovery period on a microtidal double barred beach of the NW Mediterranean Sea (Lido de SĂšte, Gulf of Lions, South France). The objective is to discuss of the key control parameters among both the forcing conditions and the morphological state of the bar/beach system. Our new dataset (high frequency topo-bathymetries and ARGUS video) clearly demonstrates the importance of the morphological variations in bar pattern along the beach. The steady alongshore difference in the outer bar depth and distance (maintained by the N.O.M. variations) has a concrete influence on the modal inner bar state and sensitivity of bar and beach profile face to the erosive processes
The Contribution of Conceptual Frameworks to Knowledge Translation Interventions in Physical Therapy
Context:
There is growing recognition of the importance of knowledge translation activities in physical therapy to ensure that research findings are integrated in clinical practice, and increasing numbers of knowledge translation interventions are being conducted. Although various frameworks have been developed to guide and facilitate the process of translating knowledge into practice, these tools have been infrequently used in physical therapy knowledge translation studies to date.
Problem and recommendation:
Knowledge translation in physical therapy implicates multiple stakeholders and environments, and involves numerous steps. In light of this complexity, the use of explicit conceptual frameworks by clinicians and researchers conducting knowledge translation interventions is associated with a range of potential benefits. In this article, we argue that such frameworks are important resources to promote the uptake of new evidence in physical therapy practice settings. We identify four key benefits associated with the use of conceptual frameworks in designing and implementing knowledge translation interventions. We also consider limits related to their use. We then evaluate a sample of five conceptual frameworks and consider how they address common barriers to knowledge translation in physical therapy. The goal of this analysis is to provide guidance to physical therapists seeking to identify a framework to support the design and implementation of a knowledge translation intervention. Finally, we illustrate the use of a conceptual framework through a case example.
Conclusion:
Increased use of conceptual frameworks can have a positive impact on the field of knowledge translation in physical therapy and support the development and implementation of robust and effective knowledge translation interventions that help span the research-practice gap
Perceptions réalistes et néoconservatrices de l'Arabie Saoudite avant et aprÚs le 11 septembre 2001
Les attaques terroristes du 11 septembre 2001 furent les Ă©vĂšnements principaux qui dĂ©terminĂšrent comment les Ătats-Unis abordĂšrent leurs relations Ă©trangĂšres par la suite. Ce fut le cas particuliĂšrement de la relation avec l'Arabie Saoudite Ă©tant donnĂ© les liens directs et indirects de ce pays avec ces attentats. Les RĂ©alistes et les NĂ©oconservateurs amĂ©ricains ont d'ailleurs construit leurs positions par rapport Ă l'Arabie Saoudite selon la nouvelle donne de la guerre contre le terrorisme qui a suivi le 11 septembre. Ainsi, RĂ©alistes et NĂ©oconservateurs basaient leurs perceptions de l'Arabie Saoudite sur sensiblement les mĂȘme arguments, tout en mettant l'accent sur ceux qui correspondaient le mieux Ă leurs positions respectives. Les RĂ©alistes et les NĂ©oconservateurs invoquaient souvent les mĂȘmes arguments pour appuyer des positions totalement diffĂ©rentes par rapport Ă l'Arabie Saoudite. Loin de rapprocher RĂ©alistes et NĂ©oconservateurs sur le dossier de l'Arabie Saoudite, les attentats du 11 septembre ont Ă©tĂ© utilisĂ©s comme justificatifs pour durcir encore d'avantage les positions antagonistes des deux groupes par rapport Ă ce pays. Le nouveau contexte international post-11 septembre n'explique donc pas adĂ©quatement Ă lui seul les perceptions opposĂ©es des RĂ©alistes et des NĂ©oconservateurs par rapport Ă l'Arabie Saoudite. Les implications de ce nouveau contexte furent Ă©tablies selon le prisme dĂ©formant de l'idĂ©ologie de l'observateur. ______________________________________________________________________________ MOTS-CLĂS DE LâAUTEUR : Ătats-Unis, Politique Ă©trangĂšre, Arabie saoudite, NĂ©oconservateurs, RĂ©alistes, 11 septembre, Terrorisme
Singular Vectors and Conservation Laws of Quantum KdV type equations
We give a direct proof of the relation between vacuum singular vectors and
conservation laws for the quantum KdV equation or equivalently for
-perturbed conformal field theories. For each degree at which a
classical conservation law exists, we find a quantum conserved quantity for a
specific value of the central charge. Various generalizations (
supersymmetric, Boussinesq) of this result are presented.Comment: 9 page
Odd Bihamiltonian Structure of New Supersymmetric N=2,4 KdV And Odd SUSY Virasoro - Like Algebra
The general method of the supersymmetrization of the soliton equations with
the odd (bi) hamiltonian structure is established. New version of the
supersymmetric N=2,4 (Modified) Korteweg de Vries equation is given, as an
example. The second odd Hamiltonian operator of the SUSY KdV equation generates
the odd N=2,4 SUSY Virasoro - like algebra.Comment: 13 pages LaTe
W-Geometries
It is shown that, classically, the W-algebras are directly related to the
extrinsic geometry of the embedding of two-dimensional manifolds with chiral
parametrisation (W-surfaces) into higher dimensional K\"ahler manifolds. We
study the local and the global geometries of such embeddings, and connect them
to Toda equations. The additional variables of the related KP hierarchy are
shown to yield a specific coordinate system of the target-manifold, and this
allows us to prove that W-transformations are simply particular diffeomorphisms
of this target space. The W-surfaces are shown to be instantons of the
corresponding non-linear -models.Comment: (13 pages
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