Development of a 3D Game Engine

This paper presents the development history and specification of a 3D game engine titled "Spark Engine". The term "engine" is used to describe a complex graphics software suite that streamlines application development and provides efficient rendering functionality. A game engine specifically provides tools to simplify game development. Spark Engine is fully shader driven and is built on top of Microsoft's XNA Framework. It is a reusable and flexible platform that can be used to build any type of graphics application ranging from gaming to simulation. The engine was released as open source software under the New BSD License with an interest in furthering its development.

Predator-Induced Plasticity in Spotted Salamanders (Ambystoma maculatum)

The ability to respond plastically to the environment has allowed amphibians to evolve adaptive responses to spatial and temporal variation in predation threat. However, animals exposed to predators may also show costs of plasticity or tradeoffs. This study examines predator-induced plasticity in larval development, behavior, and metamorphosis in the spotted salamander, Ambystoma maculatum. Salamanders were raised in two treatments: with predator cues (a fish predator, genus Lepomis, on the other side of a divided tank), or without predator cues. During the larval stage the predator treatment group experienced higher mortality rates than the no-predator treatment group. Behavioral trials revealed that predator treatment animals ate less than those not exposed, and that this feeding response was immediately inducible and had lasting effects. Animals in the predator treatment group had smaller tail areas during the mid-larval period. Feeding and body size effects may have contributed to increased mortality in the predator-treatment animals. The timing of metamorphic onset was not affected by the presence of predators, but predator-treatment salamanders had shorter snout/vent lengths at metamorphosis. The duration of metamorphosis showed a potentially adaptive plastic response to the presence of predator cues: metamorphosis was longest in the no-predator treatment group, reduced in the predator treatment group, and even further reduced for animals exposed to predator cues only during metamorphosis. Overall, we found a mix of potentially adaptive and costly plastic responses in spotted salamanders.

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.

Fort Richardson Ordnance Detonations and the Harbor Porpoise: A Case Study in Marine Mammal Bioacoustics

Hearing is extremely important for cetaceans because it is their “principal sense” (Weilgart, 2007) thus the harbor porpoise and other marine animals are highly dependent on sound for survival. This is why we should care about the impact of noise on animals like the harbor porpoise. Since sound travels so well in water, an explosion, sonar, boat noise, etc. can affect a very large area and thus many different species of marine mammals. Although military actions such as low frequency sonar have made recent news, noise has been affecting cetaceans, especially beaked whales, since at least 1991 (Weilgart, 2007). This study is an investigation of the possible impacts of artillery detonated on land on harbor porpoise hearing and covers some of the history of Fort Richardson, the legal and historical aspects and history of this type of concern, the science and physics of sound, marine mammal hearing and general biology of the harbor porpoise. Data were collected at the Fort Richardson Army base during June of 2007 by researchers from the University of Connecticut and the University of Rhode Island and will be used to determine the possible impacts that these detonations could have on the harbor porpoise.