The rôle of a chiral U(1) phase in the quark mass in QCD is analysed from first principles. In operator formulation, there is a parity symmetry and the phase can be removed by a change in the representation of the Dirac γ matrices. Moreover, these properties are also realized in a Pauli–Villars regularized version of the theory. In the functional integral scenario, attempts to remove the chiral...

Vocal tract length normalisation (VTLN) is a commonly used speaker normalisation approach. It is attractive compared to many normalisation schemes as it is typically dependent on only a single parameter, allowing the warp factors to be robustly calculated on little data. However, the scheme normally requires explicitly coding the data at multiple warp factors. Furthermore, it is only possible t...

A direct linear closed-form solution followed by Jacobian optimization is proposed to solve AX=XB for hand-eye calibration. The approach does not require A,B satisfying rigid transformation rather than the classic ones based on quaternion algebra or screw rule, so the technique is more flexible. Rigid deduction and demonstration are given based on matrix theory. Computer simulation and real dat...

Dhiraj Nahar, Thomas Sugar, Paul Fussell Mechanical and Aerospace Engineering Arizona State University Tempe, AZ-85281 Abstract: In this paper, we are solving two inverse design problems. We first determine the desired Cartesian stiffness matrix for each contact in a multi-contact grasp by solving an optimization problem. Secondly given the desired stiffness matrix, K, for each contact, we desi...

This paper derives a 2D, quasi-linear Schrödinger equation in Lagrangian coordinates that describes the effects of weak pressure gradients on large amplitude inertial oscillations in a rotating shallow fluid. The coefficients of the equation are singular at values of the gradient of the wave amplitude that correspond to the vanishing of the Jacobian of the transformation from Lagrangian to Eule...

An implementation of Automatic Sparsity Detection (ASD) as a new source-to-source transformation is presented. Given a code for evaluation of a function, ASD generates code to evaluate the sparsity pattern of the function’s Jacobian by operations on bit-vectors. Similar to Automatic Differentiation (AD), there are forward and reverse modes of ASD. As ASD code has significantly fewer required va...

Top row: (a) a brain image (I1) with a predefined ROI; (b) I1 after a simulated 29.2% atrophy of the ROI (I2); (c) deformed I1 to I2 using IRG overlaid by the simulated ROI. Bottom row: log Jacobian of the simulated transformation by IRG. Deformation Based Morphometry with Implicit Reference-Based Registration: Validation and Detection of Structural Changes in a Primate Model of Early-Life Stress

Gregory S. Chirikjian Johns Hopkins University 2.1 Rotations in Three Dimensions Rules for Composing Rotations • Euler Angles • The Matrix Exponential 2.2 Full Rigid-Body Motion Composition of Motions • Screw Motions 2.3 Homogeneous Transforms and the Denavit-Hartenberg Parameters Homogeneous Transformation Matrices • The Denavit-Hartenberg Parameters in Robotics 2.4 Infinitesimal Motions and A...