We present two fourth-order compact finite difference (CFD) discretizations of the velocity-pressure formulation of the acoustic wave equation in 2-D rectangular grids. The first method uses standard implicit CFD on nodal meshes and requires solving tridiagonal linear systems along each grid line, while the second scheme employs a novel set of mimetic CFD operators for explicit differentiation ...

In this paper, we study the integration of Hamiltonian wave equations whose solutions have oscillatory behaviors in time and/or space. We are mainly concerned with the research for multi-symplectic extended Runge-Kutta-Nyström (ERKN) discretizations and the corresponding discrete conservation laws. We first show that the discretizations to the Hamiltonian wave equations using two symplectic ERK...

In classical photometric stereo, a Lambertian surface is illuminated from multiple distant point light-sources. In the present paper we consider nearby lightsources instead, so that the unknown surface, is illuminated by non-parallel beams of light. In continuous noiseless cases, the recovery of a Lambertian surface from non-distant illuminations, reduces to solving a system of non-linear parti...

The velocity and stress autocorrelation decay in a dissipative particle dynamics ideal fluid model is analyzed in this paper. The autocorrelation functions are calculated at three different friction parameters and three different time steps using the well-known Groot/Warren algorithm and newer algorithms including self-consistent leap-frog, self-consistent velocity Verlet and Shardlow first and...

Submitted for the MAR08 Meeting of The American Physical Society Angular momentum form of Verlet algorithm for rigid molecules MIYABI HIYAMA, CREST, Toyota Central R&D Labs., Inc., TOMOYUKI KINJO, SHIAKI HYODO, Toyota Central R&D Labs., Inc. — We seek to make an algorithm based on the Verlet method which could be applied to non-Hamiltonian and explicit time dependent Hamiltonian systems for rig...

We present a “leap-frog” path designed for a team of three robots performing cooperative localization. Two robots act as stationary measurement beacons while the third moves in a path that provides informative measurements. After completing the move, the roles of each robot are switched and the path is repeated. We demonstrate accurate localization using this path via a coverage experiment in w...

This paper presents the realization of third-order low-pass active-RC filters using a new Leap-Frog (LF) topology. New structure is a simplified LF structure with the elements calculated directly from the transfer function coefficients. Several versions of the circuits are presented and compared. The comparison to other common thirdorder filter sections is done, as well. The new LF filter has t...