In κ-deformed relativistic framework we consider three different definitions of κ-deformed velocities and introduce corresponding addition laws. We show that one of the velocities has classical relativistic addition law. The relation of velocity formulae with the coproduct for fourmomenta and noncommutative space-time structure is exhibited.

Let F be a field and A a free associative F -algebra or a group algebra of a free group with an infinite set X of generators. We find a necessary and sufficient condition for the inclusion I ′ ⊆ I , where I = I1 . . . Ik and I ′ = I ′ 1 . . . I ′ l are any products of T -ideals in A. A canonical reformulation in terms of products of group representation varieties answers a question posed in 198...

Besides the actual state of the condition, the performance of an athlete is highly influenced by the way of executing the movement. So this factor is said to be more and more important. In order to find out and use these potentials, sport science profits from the power of computers for example with modelling and simulating special movements. This article describes the basic functions of a model...

The aim of this paper is the kinematic study of a 3-RPR planar parallel manipulator where the three fixed revolute joints are actuated. The direct and inverse kinematic problem as well as the singular configuration is characterized. On parallel singular configurations, the motion produce by the mobile platform can be compared to the Reuleaux straight-line mechanism.

This paper compares morphological and functional definitions of the flexion-extension axis using six dof electrogoniometry and bone Modelling.

Consider the square lattice Z with vertices at points with integer-valued coordinates in R = {(x1, x2)| xk ∈ R, k = 1, 2} and complex (or real) scalar fields u on the lattice Z, u : Z → C, that are defined by their values ui1i2 , ui1i2 ∈ C, at each vertex of the lattice with the coordinates (i1, i2), ik ∈ Z, k = 1, 2. Consider a class of two-dimensional discrete equations on the lattice Z for t...

Matrix relations in kinematics and dynamics of the Star parallel manipulator are established in this paper. The prototype of the manipulator is a three-degree-of-freedom mechanism, which consists of a system of parallel kinematical chains connecting to a moving platform. Knowing the translation motion of the platform, we develop first the inverse kinematics problem and determine the position, v...

In this paper, the inverse kinematics and inverse dynamics analysis of a parallel mechanism is presented. The mechanism consists of three fixed-length legs each supported by a three-wheeled mobile robot. The three legs support a platform, which acts as the end-effector of the mechanism. Two different designs are evaluated: one with ball joints at the top ends of the legs and revolute joints at ...