The consequences of rotational-symmetry breaking in Heisenberg spin-glasses are studied with use of order parameters which are time-dependent SO(3) rotation matrices. A microscopic derivation of the hydrodynamic "triad" theory, including the effect of small magnetic fields and random anisotropies, is presented. In the mean-field limit the finitetime exchange stiffness and macroscopic anisotropy...

A parallelogram allows the output link to remain at a fixed orientation with respect to an input link, for which it acts as a unique role in the design of parallel mechanisms. In this paper, the unique role of a parallelogram is used completely to design some new parallel mechanisms with two to six degrees of freedom (DoFs). In these mechanisms, some with three DoFs possess the advantage of ver...

The design and fabrication process for a high performance manipulation stage for nanometer resolution TEM sample positioning over a 20 m range is presented. A two level, planar stage is moved in three translational and three rotational directions by just two types of actuators; three horizontal and three vertical combdrives. The vertical combdrives are suspended by optimally designed torsion-be...

Achieving adequate force control is an important problem in the application of robotics technology to manufacturing tasks. This is particularly true for assembly tasks that require constrained interaction between a robotic manipulator and a workpart. One approach to this problem is the use of passive compliance. A number of methods have been proposed for designing a passive compliance mechanism...

This paper presents a systematic approach to quantifying the effectiveness of compliant grasps and fixtures of an object. The approach is physically motivated and applies to the grasping of twoand three-dimensional objects by any number of fingers. The approach is based on a characterization of the frame-invariant features of a grasp or fixture stiffness matrix. In particular, we define a set o...

After clutch engagement in the post-lockup phase, the contact stiffness between friction materials and separators plays an important role in the dynamic behaviour of an Automatic Transmission (AT). The friction material deteriorates progressively during the service-life of a clutch, thus affecting the contact stiffness. The deterioration therefore changes the dynamic behaviour of the AT. In ord...