Oceanic turbulence

For secure communications, the authors propose a underwater wireless optical communications code-division multiple-access (UOWC/CDMA) system with multiple relay assistance. Relay nodes employ the Chip Detect-and-Forward (CDF) technique to prevent the difficult multiuser decoding procedure. The proposed system performance, in terms of bit-error rate (BER) and transmission confidentiality, is analyzed in our study over fading channel.

11p vithomson 02-07-2024 0 0   Download

The reliability of an underwater wireless optical communication (UWOC) network is seriously impacted by oceanic turbulence and beam misalignment between transmitters (Tx) and receivers (Rx).

7p viannee 02-08-2023 5 4   Download

A velocity field obtained from the ocean surface by high-frequency radar is used to test Lagrangian prediction algorithms designed to evaluate the position of a particle given its initial position and observations of several other simultaneously released particles. The problem is motivated by oceanographic applications such as search and rescue operations and spreading pollutants, especially in coastal regions.

16p vidonut2711 09-11-2019 13 1   Download

Computational Fluid Dynamics, broadly encompassing fluid flows in engineering, atmospheric and ocean sciences, geophysics, physics and astrophysics, has seen calculations of great fidelity performed routinely that were only imagined at the inception of this conference series in 1989. These advances have not only been made with the available horsepower of increasingly more powerful parallel computers, but in tandem with advances in implementations of core and of entirely new algorithms, including multi-scale and adaptive methods....

0p bachduong1311 07-12-2012 54 1   Download

Estimating the transport and fate of chemicals released into the environment is an interesting and challenging task. The global environment is large on the chemical transport and fate scale. This text applies the mathematics of diffusion, turbulent diffusion, and dispersion to the atmosphere, lakes, rivers, groundwater, and oceans, as well as transport between these media. The book follows a new educational paradigm of textbooks, in that it is based on examples and case studies.

295p nhulan0908 29-09-2012 82 22   Download

Aquatic scientists have always been intrigued with concepts of scale. This interest perhaps stems from the nature of ßuid dynamics in oceans and lakes — energy cascades from spatial scales of kilometers down to viscous scales at centimeters or less. Turbulent processes affect not only an organism’s perception of, and response to, the physical environment, but also the interaction between species, both within and across trophic levels.

0p 951628473 07-05-2012 68 9   Download

The next chapter describes how a conventional model of ocean-atmosphere interaction can be modified to include the free convection within the air and the swell of the ocean. These effects become particularly important for low wind velocities, where the standard Charnock wind stress formula leads to a singularity. The article should be of particular interest to readers who are familiar with standard turbulence modeling, and it is important to weather modeling.

168p contentnew 12-04-2012 164 21   Download