Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 8 of 8 for “"Equinoctial"”.
-
Equinoctial: an investigation of ‘the holographic’ for developing a new collection of ekphrastic poetry
… research and my collection of poetry Equinoctial arising from it derives its structure, and the linguistic and formal properties of its poems, from a process of holographic enquiry arising from processes of holography and the properties of holograms. Furthermore, I construe this …
-
Lyapunov feedback control in equinoctial elements applied to low thrust control of elliptical orbit constellations
For a typical satellite constellation design problem, sometimes there are two conflicting goals. On one hand one wishes to provide continuous coverage of a particular area. On the other hand one would like to use the minimum number of satellites as possible. For coverage locations nearer the …
-
Characterisation of ionospheric TEC variations over the equatorial and polar regions during solar cycle 24
… at both stations encountered the highest TEC at equinoctial months and the lowest value at solstitial months. However, in 2009, the seasonal TEC showed the highest and lowest TEC peak, both at equinoctial months at NYA1 station. During geomagnetic days, the enhancement percentages of TEC are …
-
Extreme sea levels around the coast of Southern Africa
… in Southern African extremes. The fortnightly, equinoctial and 4.4 year tidal cycles determine the expected sea level extremes. A prediction technique developed here makes use of the tidal dominance by calculating the likelihood of exceedance for a specific month in a particular year. For any …
-
Relative Position Control for Satellite Formation Flying
… A custom simulator is developed using a modified equinoctial element based propagator to allow for advanced visualisation and controller evaluation. Two Model Predictive Controllers (MPCs) were designed to showcase how effective this control architecture is under different state representations. …
-
Elias Allen and the role of instruments in shaping the mathematical culture of seventeenth-century England
… and double horizontal dial, and the universal equinoctial ring dial. These are described, their uses explained, and used as the base for discussions of the ways in which instruments influenced and were influenced by the development of mathematics. This section concludes with a catalogue of all …
-
Orbital Maneuvers and Interplanetary Trajectory Design via Reinforcement Learning
… variational equations expressed in modified equinoctial elements, allowing for efficient handling of low-thrust propulsion and long-duration transfers. Several RL algorithms, including Proximal Policy Optimization and Soft Actor-Critic, are implemented and evaluated across a diverse set of …
-
Optimal control techniques for multimode propulsion mission design in cislunar space
… a new technique is developed using modified equinoctial elements (MEE), HTS, forward-backward multiple shooting, two reference frames (Earth-centered and Moon-centered), and highly consistent dynamics. The method is demonstrated with multiple two-mode transfers as well as a three-mode …