The aim of this paper is to present a system that detects the hand gesture motions using the principle of Doppler Effect. Ultrasonic waves are transmitted by a sensor module and are reflected by a moving hand. The received waves are frequency shifted due to Doppler Effect. These frequency shifts in the ultrasonic waves are characterized to determine gestures. The gestures once recognized are ma...

A state of the art numerical tool has been developed to simulate the QsTj propagation and the absorption of coexisting diffemt types of waves in a tokamak geometxy. The code includes a numerical solution of the three-dimensional (R, Z, 0) toroidal wave equation for the electric field of the different waves in the WKBJ approximation. At each step of integration, the two-dimensional (VI!, v~ Fokk...

Is light transmitted by particles or waves? The basic dilemna here (which dates as far back as Newton) is to reconcile the evidence that light is transmitted by particles (called photons), with experiments demonstrating the wave nature of light. To be concrete, let us recall Young’s double-slit experiment from high school physics, which was used to demonstrate the wave nature of light. The appa...

An investigation of reflection and transmission phenomena of plane longitudinal wave from a plane interface between two distinct micropolar porous elastic solid half-spaces in welded contact has been made. Using the method of potentials, the appropriate boundary conditions at the interface are solved to obtain the amplitudes of various reflected and transmitted waves. It has been noticed that t...

This paper considers the statistical properties of the waves generated by a point source in the subsurface and transmitted towards the surface through a randomly layered medium. The problem is analyzed in a regime of separation of scales and with pressure release boundary conditions at the surface. Using a probabilistic representation of the spectral density of the waves received at the surface...

The propagation of borehole acoustic waves in the presence of various types of heterogeneous formations is investigated by modeling them as stratified media with varying velocity-depth distributions. Two types of formations are modeled, using translational and cyclic random models, respectively. Borehole acoustic wavefields for the heterogeneity formation models are simulated using finite-diffe...

We study transport and di usion of classical waves in two-dimensional disordered systems and in particular surface waves on a at surface with randomly uctuating impedance. We derive from rst principles a radiative transport equation for the angularly resolved energy density of the surface waves. This equation accounts for multiple scattering of surface waves as well as for their decay because o...

It is shown by way of nonlinear numerical simulations of flow restricted to two dimensions that a compact wavepacket of large-amplitude internal gravity waves incident upon a weakly stratified region in which the buoyancy frequency is less than the frequency of the wavepacket may partially transmit energy into this region through the generation of a wavepacket of lower frequency. In part, the t...

A dual-polarization lidar and photography are used to sense internal waves in West Sound, Orcas Island, Washington, from a small aircraft. The airborne lidar detected a thin plankton layer at the bottom of the upper layer of the water, and this signal provides the depth of the upper layer, amplitude of the internal waves, and the propagation speed. The lidar is most effective when the polarizat...

An analytical technique referred to as the propagator matrix method (PMM) is presented to study the problem of electromagnetic (EM) waves interacting with the nonuniform magnetized plasma. In this method, the state vector is proposed to describe the characteristics of eigen waves in anisotropic medium, and state vectors at two different locations are related with each other by the propagator ma...