Written in English
|Contributions||Ziomek, Lawrence J.|
|The Physical Object|
|Number of Pages||63|
In this paper, localization in inhomogeneous underwater medium for an asynchronous UASN has been addressed based on received signal strength (RSS) measurements. At the first step, the transmission loss of acoustic wave between source and target sensors was derived in inhomogeneous underwater medium with an isogradient sound speed by: 7. Sound source localization in a randomly inhomogeneous medium using matched statistical moment method Article in The Journal of the Acoustical Society of America (6) December We study interaction-induced localization of electrons in an inhomogeneous quasi-one-dimensional system — a wire with two regions, one at low density and the other high. Quantum Monte Carlo techniques are used to treat the strong Coulomb interactions in the low-density region, where localization of electrons occurs. where E(r) and H(r) are the electric and magnetic strengths, ε(r) is the dielectric permittivity of the medium, and k = ω/c = 2π/λ is the wave number (λ is the wavelength and c is the velocity of wave propagation). Here, we assumed that magnetic permeability μ = 1, medium conductivity σ = 0, and specified temporal factor e −iωt for all fields.
In this paper, we present a new approach for the defect modes localization. Rather than focusing on the original objective and optimizing the structure along the gradient, a variant of the original problem is put forward with its corresponding method. TY - CHAP. T1 - Short range propagation through an inhomogeneous medium. AU - Pace, Nicholas G. AU - Wood, William J. AU - Jones, C M A. N1 - OCEANS' Oceans Engineering for Today's Technology and Tomorrow's Preservation. September It is well known that the focussing of an ultrasonic beam on a target is a difficult operation since it requires a previous localization. The problem is increased if the propagation medium shows local inhomogeneities (spatial variations of the compressibility and/or density) since, in that case, the acoustic beam is distorted. Get this from a library! Holography in a spatially inhomogeneous medium. [Harold T Yura; Rand Corporation.] -- A Huygens-Fresnel principle, extended to a medium which exhibits a spatial variation in the index of refraction, is used to calculate the resulting .
 As for the localization/tracking of the target, the problem at hand can be classified into two main categories: localization/tracking of cooperative targets and localization/tracking of noncooperative targets. In the former case (), the target is equipped with a node or a transponder (tag) that transmits/receives localization is called “collaborative” (or “active. inhomogeneous medium is that the nal momentum injec-tion is remarkably insensitive to the environment, di ering by only 5 30 per cent compared to evolution in a homo-geneous environment of the same average density (I rig & Hennebelle;Kim & Ostriker;Martizzi et al; Walch & Naab). In a small minority of galaxy formation simulations. Accurate focusing in an inhomogeneous medium is difficult to implement. In order to focus on a reflective target we have extended the concept of optical phase‐conjugate mirrors, valid for monochromatic signals, to broadband pulses such as those used in ultrasound echography. The transducer’s linear response to the acoustic pressure allows one to replace the phase conjugation by . Abstract: In an underwater medium the sound speed is not constant, but varies with depth. This phenomenon upsets the linear dependency of the distance traveled by an acoustic wave to the time it takes for the wave to travel that distance, and therefore makes existing distance-based localization algorithms less effective in an underwater environment.