Three approaches to nuclear and hadronic collective motion are reviewed, compared and contrasted: the standard symmetry approach as typified by the Interacting Boson Model, the kinematic symmetry group approach of Gell-Mann and Tomonaga, and the recent direct construction by Buck. (Invited paper presented at the Symposium on Group Theory and Its Applications in Physics, Cocoyoc, Morelos, Mexico...

We seek intuitive, e cient ways to create and direct human-like behaviors for humanoid robots. Here we present a method to enable humanoid robots to acquire movements by imitation. The robot uses 3D vision to perceive the movements of a human teacher, and then estimates the teacher's body postures using a fast full-body inverse kinematics method that incorporates a kinematic model of the teache...

In this paper we present the current state of our research on simulation of temporal bone surgical procedures. We describe the results of tests performed on a virtual surgical training system for middle ear surgery. The work is aimed to demonstrate how expert surgeons and trainees can effectively use the system for training and assessment purposes. Preliminary kinematic and dynamic analysis of ...

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...

Compared with serial structured machine tools and robots, parallel kinematic machine tools and robots have many advantages. Many different topologies of parallel mechanisms with 3-6 DOF have been used. Considering that some limitations are indeed due to the use of parallel mechanisms, it is appealing to investigate architectures based on hybrid arrangements where serial and parallel concepts ar...

This article presents a novel parallel spherical mechanism called Argos with three rotational degrees of freedom. Design aspects of the first prototype built of the Argos mechanism are discussed. The direct kinematic problem is solved, leading always to four nonsingular configurations of the end effector for a given set of joint angles. The inverse-kinematic problem yields two possible configur...

Detailed statistical models of body size and shape are valuable for wide range of statistical analyses. Most body shape models represent a single posture, usually standing. Previous efforts to model both posture and body shape have parameterized posture using joint angles. This paper presents a statistical model of body shape in supported seated postures using a posture measured derived from su...