Some rigorous results can be derived using a very simple approach to hadron spectroscopy, in which a static potential is associated with non-relativistic kinematics. Several regularities of the experimental spectrum are explained by such models. It is underlined that certain methods developed for hadronic physics have found applications in other fields, in particular atomic physics. A few resul...

We examine, in a general setting, a notion of inverse semigroup of left quotients, which we call left I-quotients. This concept has appeared, and has been used, as far back as Clifford’s seminal work describing bisimple inverse monoids in terms of their right unit subsemigroups. As a consequence of our approach, we find a straightforward way of extending Clifford’s work to bisimple inverse semi...

Let n, k be positive integers, with k ≤ n, and let τ be a fixed permutation of {1, . . . , k}. We will call τ the pattern. We will look for the pattern τ in permutations σ of n letters. A pattern τ is said to occur in a permutation σ if there are integers 1 ≤ i1 < i2 < . . . < ik ≤ n such that for all 1 ≤ r < s ≤ k we have τ(r) < τ(s) if and only if σ(ir) < σ(is). Example: Suppose τ = (132). Th...

This article presents a biomechanical model of the right arm, developped with respect to the functional anatomy of the human. This model is developped as a motion analysis tool. The main application issued from this model is the muscle forces estimation of the flexion/extension and internal rotation of the forearm joints. This estimation is based on an inverse dynamics method, improved with add...