Visualizing the Simulation of 3-D Underwater Sensor Networks

The majority of sensor network research deals with land-based networks, which are essentially two-dimensional, and thus the majority of simulation and animation tools also only handle such networks. Underwater sensor networks on the other hand, are essentially 3D networks because the depth at which a sensor node is located needs to be considered as well. Due to that additional dimension, specialized tools need to be used when conducting simulations for experimentation. The School of Engineering’s Underwater Sensor Network (UWSN) lab is conducting research on underwater sensor networks and requires simulation tools for 3D networks. The lab has extended NS-2, a widely used network simulator, so that it can simulate three-dimensional networks. However, NAM, a widely used network animator, currently only supports two-dimensional networks and no extensions have been implemented to give it three-dimensional capabilities. In this project, we develop a network visualization tool that functions similarly to NAM but is able to render network environments in full 3-D. It is able to take as input a NS-2 trace file (the same file taken as input by NAM), create the environment, position the sensor nodes, and animate the events of the simulation. Further, the visualization tool is easy to use, especially friendly to NAM users, as it is designed to follow the interfaces and functions similar to NAM. So far, the development has fulfilled the basic functionality. Future work includes fully functional capabilities for visualization and much improved user interfaces.

Some Law and Economics of Historic Shipwrecks

This paper examines how US and proposed international law relate to the recovery of archaeological data from historic shipwrecks. It argues that US federal admiralty law of salvage gives far less protection to historic submerged sites than do US laws protecting archaeological sites on US federal and Indian lands. The paper offers a simple model in which the net present value of the salvage and archaeological investigation of an historic shipwreck is maximized. It is suggested that salvage law gives insufficient protection to archaeological data, but that UNESCO's Convention on the Protection of the Underwater Cultural Heritage goes too far in the other direction. It is also suggested that a move towards maximizing the net present value of a wreck would be promoted if the US admiralty courts explicitly tied the size of salvage awards to the quality of the archaeology performed.