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This thesis presents an automatic animation system for jellyfish that is based on a physical simulation of the organism and its surrounding fluid. Our goal is to explore the unusual style of locomotion, namely jet propulsion, which is utilized by jellyfish. The organism achieves this propulsion by contracting its body, expelling water, and propelling itself forward. The organism then expands again to refill itself with water for a subsequent stroke. We endeavor to model the thrust achieved by the jellyfish, and also the evolution of the organism's geometric configuration. <p> We restrict our discussion of locomotion to fully grown adult jellyfish, and we restrict our study of locomotion to the resonant gait, which is the organism's most active mode of locomotion, and is characterized by a regular contraction rate that is near one of the creature's resonant frequencies. We also consider only species that are axially symmetric, and thus are able to reduce the dimensionality of our model. We can approximate the full 3D geometry of a jellyfish by simulating a 2D slice of the organism. This model reduction yields plausible results at a lower computational cost. From the 2D simulation, we extrapolate to a full 3D model. To prevent our extrapolated model from being artificially smooth, we give the final shape more variation by adding noise to the 3D geometry. This noise is inspired by empirical data of real jellyfish, and also by work with continuous noise functions from the graphics community. <p> Our 2D simulations are done numerically with ideas from the field of computational fluid dynamics. Specifically, we simulate the elastic volume of the jellyfish with a spring-mass system, and we simulate the surrounding fluid using the semi-Lagrangian method. To couple the particle-based elastic representation with the grid-based fluid representation, we use the immersed boundary method. We find this combination of methods to be a very efficient means of simulating the 2D slice with a minimal compromise in physical accuracy.

This thesis presents an automatic animation system for jellyfish that is based on a physical simulation of the organism and its surrounding fluid. Our goal is to explore the unusual style of locomotion, namely jet propulsion, which is utilized by jellyfish. The organism achieves this propulsion by contracting its body, expelling water, and propelling itself forward. The organism then expands again to refill itself with water for a subsequent stroke. We endeavor to model the thrust achieved by the jellyfish, and also the evolution of the organism's geometric configuration. <p> We restrict our discussion of locomotion to fully grown adult jellyfish, and we restrict our study of locomotion to the resonant gait, which is the organism's most active mode of locomotion, and is characterized by a regular contraction rate that is near one of the creature's resonant frequencies. We also consider only species that are axially symmetric, and thus are able to reduce the dimensionality of our model. We can approximate the full 3D geometry of a jellyfish by simulating a 2D slice of the organism. This model reduction yields plausible results at a lower computational cost. From the 2D simulation, we extrapolate to a full 3D model. To prevent our extrapolated model from being artificially smooth, we give the final shape more variation by adding noise to the 3D geometry. This noise is inspired by empirical data of real jellyfish, and also by work with continuous noise functions from the graphics community. <p> Our 2D simulations are done numerically with ideas from the field of computational fluid dynamics. Specifically, we simulate the elastic volume of the jellyfish with a spring-mass system, and we simulate the surrounding fluid using the semi-Lagrangian method. To couple the particle-based elastic representation with the grid-based fluid representation, we use the immersed boundary method. We find this combination of methods to be a very efficient means of simulating the 2D slice with a minimal compromise in physical accuracy.

This thesis studies the development of the Royal Australian Navy (RAN), during the period 1911 to 1952 from the perspective of the men of the lower deck, the RAN ratings. The early RAN was modelled very closely on the Royal Navy (RN), but the expectations of its managers and administrators, imbued as they were with the culture and tradition of the RN, were not easily compatible with the character of the Australians who became the RAN???s ratings. The class distinction which functioned in the RN, when applied to the more egalitarian Australians caused ill-feeling and led to the breakdown of discipline. The Australian Commonwealth Naval Board strongly resisted attempts by the Australian Government and the Australian people to regulate its affairs, a situation which seriously disadvantaged the RAN ratings and their families. In the wider context a continuing refusal by both the British Admiralty and the senior officers of the RAN to allow the development of a truly national navy led to significant manpower problems. This both inhibited the establishment of a navy for Australia and denied that navy full use of the unique attributes of the Australian rating.

This thesis studies the development of the Royal Australian Navy (RAN), during the period 1911 to 1952 from the perspective of the men of the lower deck, the RAN ratings. The early RAN was modelled very closely on the Royal Navy (RN), but the expectations of its managers and administrators, imbued as they were with the culture and tradition of the RN, were not easily compatible with the character of the Australians who became the RAN???s ratings. The class distinction which functioned in the RN, when applied to the more egalitarian Australians caused ill-feeling and led to the breakdown of discipline. The Australian Commonwealth Naval Board strongly resisted attempts by the Australian Government and the Australian people to regulate its affairs, a situation which seriously disadvantaged the RAN ratings and their families. In the wider context a continuing refusal by both the British Admiralty and the senior officers of the RAN to allow the development of a truly national navy led to significant manpower problems. This both inhibited the establishment of a navy for Australia and denied that navy full use of the unique attributes of the Australian rating.