A new biometric identification method is introduced in which a user “writes” his or her signature in the air. Accelerometers worn on a wrist device transmit acceleration data wirelessly to a host computer that processes the data and authenticates the user. This paper describes the use of curvature moments associated with 3D curves in both configuration space and velocity space as the features u...

A VECTOR SCANNING PROCESSING TECHNIQIJE FOR PULSED LASER VELOCIMETRY Mark P. Wernet National Aeronautics and Space Administration Lewis Research Center Cleveland, Ohio 4113.5 and Robert V. Edwards Case Western Reserve University Dept. of Chemical Engineering Cleveland, Ohio 44106 by Pulsed laser sheet velocimetry yields non-intrusive measurements of two-dimensional velocity vectors across an ex...

[1] It is shown that the low frequency plasma wave equation can be obtained much more directly than by the previously used method of solving for the determinant of a matrix involving the three components of the electric field vector. The more direct method uses a two-dimensional current density vector space that is precisely equivalent to the previously used three-dimensional electric field vec...

Maintaining and controlling postural balance is important for activities of daily living, with poor postural balance being predictive of future falls. This study investigated eyes open and eyes closed standing posturography with elderly adults to identify differences and determine appropriate outcome measure cut-off scores for prospective faller, single-faller, multi-faller, and non-faller clas...

This paper develops the analytical framework to compare the approximate performance of periodic hypersonic cruise trajectories with previously proposed hypersonic trajectory prooles for global reach. Speciically, range, V and payload carrying capacity are evaluated for various trajectory types to illustrate the enhanced performance achieved by y-ing periodic hypersonic cruise trajectories with ...

BACKGROUND Understanding hemodynamic environment in vessels is important for realizing the mechanisms leading to vascular pathologies. OBJECTIVES Three-dimensional velocity vector field in carotid bifurcation is visualized using TR 3D phase-contrast magnetic resonance imaging (TR 3D PC MRI) and computational fluid dynamics (CFD). This study aimed to present a qualitative and quantitative comp...

In an isotropic, homogeneous, nondissipative, dielectric–magnetic medium that is simply moving with respect to an inertial reference frame, planewave solutions of the Maxwell curl postulates can be such that the phase velocity and the time–averaged Poynting vector are mutually orthogonal. Orthogonal–phase–velocity propagation thus adds to the conventional positive–phase–velocity propagation and...

For a given velocity and temperature eld in a diierentially moving 3D medium, the vector of the radiative ux is derived in the diiusion approximation. Due to the dependence of the velocity gradient on the direction, the associated eeective opacity in general is a tensor. In the limit of small velocity gradients analytical expression are obtained which allow us to discuss the cases when the dire...