Background Accurate measurements of skeletal kinematics of the foot would increase our understanding on the interaction between foot and footwear. Previously foot kinematics was measured using reflective markers but the method had inherent limitation of skin marker-based methods. Recently fluoroscopic imaging-based methods has been developed and widely used to measure knee kinematics [1,2]. We ...

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...

This paper presents an algorithm for detecting and computing the cusp points in the joint space of 3-RPR planar parallel manipulators. In manipulator kinematics, cusp points are special points, which appear on the singular curves of the manipulators. The nonsingular change of assembly mode of 3-RPR parallel manipulators was shown to be associated with the existence of cusp points. At each of th...

In this paper we consider a complete dynamic model for the \Sphericle", a spherical vehicle that has been designed and realized in our laboratory. The sphericle is able to roll on the oor of the laboratory and reach arbitrary positions and orientations, through the use of only two motors placed within the rolling sphere. In this paper, we report on the derivation of the kinematic model of the S...

The ball-and-socket joint model is used to represent articulations with three rotational degrees of freedom (DOF), such as the human shoulder and the hip. The goal of this paper is to discuss two related problems: the parametrization and the deÞnition of realistic joint boundaries for ball-andsocket joints. Doing this accurately is difÞcult, yet important for motion generators (such as inverse ...

In this paper we concentrate on some important timing characteristics of Elevator Group Control (EGC) systems. The main discussion and calculations should be considered as a further development of Three Passages (TP) concept, already presented in our previous papers. To achieve better global performance of EGC system, especially to reduce hall call waiting time, calculation methodology of car k...

We present a systematical analysis of uncertainties in the helioseismological determination of quantities characterizing the solar structure. We discuss the effect of errors on the measured frequencies, the residual solar model dependence and the uncertainties of the inversion method. We find Y ph = 0.238 − 0.259, R b /R ⊙ = 0.708 − 0.714 and ρ b = (0.185 − 0.199) gr/cm 3 (the index b refers to...