The stiiness of a rigid body subject to conservative forces and moments is described by a tensor, whose components are best described by a 6 6 Cartesian stiiness matrix. We derive an expression that is independent of the parameterization of the motion of the rigid body using methods of diierential geometry. The components of the tensor with respect to a basis of twists are given by evaluating t...

A bar-slider framework is a bar-joint framework a part of whose joints are constrained by using line-sliders. Such joints are allowed to move only along the sliders. Streinu and Theran proposed a combinatorial characterization of the infinitesimal rigidity of generic bar-slider frameworks in two dimensional space. In this paper we propose a generalization of their result. In particular, we prov...

EM1 associated with inter-board connection was studied through common-mode current measurements and FDTD modeling for stacked-card and module-on-backplane configurations. Three types of connections were investigated experimentally including an open pin field connection, an “ideal” semi-rigid coaxial cable connection, and a production connector. Both microstrip and stripline signal routing on th...

We investigate the relationship between conformal and spin structure on lorentzian manifolds and see how their compatibility influences the formulation of rigid supersymmetric field theories. In dimensions three, four, six and ten, we show that if the Dirac current associated with a generic spinor defines a null conformal Killing vector then the spinor must obey a twistor equation with respect ...

This paper solves an open problem posed by a number of researchers: the construction of a complete calculus for matrix-based methods with rigid E-uniication. The use of rigid E-uniication and simultaneous rigid E-uniication for such methods has been proposed in (Gallier et al., 1987). After our proof of the undecidability of simultaneous rigid E-uniication (Degtyarev and Voronkov, 1996e) it has...

Twisted geometry is a piecewise-flat geometry less rigid than Regge geometry. In Loop Gravity, it provides the classical limit for each step of the truncation utilized in the definition of the quantum theory. We define the torsionless spin-connection of a twisted geometry. The difficulty given by the discontinuity of the triad is addressed by interpolating between triads. The curvature of the r...