Techn. Universiẗat, Diss.--Clausthal, 2008. / Enth. außerdem 3 Originalpublikationen.

Mannheim, Univ., Diss., 2006.

Thesis (Ph. D.)--Michigan State University. Dept. of Electrical and Computer Engineering, 2006. / Title from PDF t.p. (viewed on Nov. 17, 2008) Includes bibliographical references (p. 155-160). Also issued in print.

Thesis (M.S.)--Rochester Institute of Technology, 1993. / Typescript. Includes bibliographical references.

Zugl.: Tübingen, Univ., Diss., 2009

Thesis (M. S.)--Mechanical Engineering, Georgia Institute of Technology, 2006. / Dr. Jonathan Colton, Committee Chair ; Dr. John Muzzy, Committee Member ; Dr. Daniel Baldwin, Committee Member ; Dr. John Schultz, Committee Member.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

This thesis considers the domain of acoustic source localisation and tracking in an indoor environment. Acoustic tracking has applications in security, human-computer interaction, and the diarisation of meetings. Source localisation and tracking is typically a computationally expensive task, making it hard to process on-line, especially as the number of speakers to track increases. Much of the literature considers single-source localisation, however a practical system must be able to cope with multiple speakers, possibly active simultaneously, without knowing beforehand how many speakers are present. Techniques are explored for reducing the computational requirements of an acoustic localisation system. Techniques to localise and track multiple active sources are also explored, and developed to be more computationally efficient than the current state of the art algorithms, whilst being able to track more speakers. The first contribution is the modification of a recent single-speaker source localisation technique, which improves the localisation speed. This is achieved by formalising the implicit assumption by the modified algorithm that speaker height is uniformly distributed on the vertical axis. Estimating height information effectively reduces the search space where speakers have previously been detected, but who may have moved over the horizontal-plane, and are unlikely to have significantly changed height. This is developed to allow multiple non-simultaneously active sources to be located. This is applicable when the system is given information from a secondary source such as a set of cameras allowing the efficient identification of active speakers rather than just the locations of people in the environment. The next contribution of the thesis is the application of a particle swarm technique to significantly further decrease the computational cost of localising a single source in an indoor environment, compared the state of the art. Several variants of the particle swarm technique are explored, including novel variants designed specifically for localising acoustic sources. Each method is characterised in terms of its computational complexity as well as the average localisation error. The techniques’ responses to acoustic noise are also considered, and they are found to be robust. A further contribution is made by using multi-optima swarm techniques to localise multiple simultaneously active sources. This makes use of techniques which extend the single-source particle swarm techniques to finding multiple optima of the acoustic objective function. Several techniques are investigated and their performance in terms of localisation accuracy and computational complexity is characterised. Consideration is also given to how these metrics change when an increasing number of active speakers are to be localised. Finally, the application of the multi-optima localisation methods as an input to a multi-target tracking system is presented. Tracking multiple speakers is a more complex task than tracking single acoustic source, as observations of audio activity must be associated in some way with distinct speakers. The tracker used is known to be a relatively efficient technique, and the nature of the multi-optima output format is modified to allow the application of this technique to the task of speaker tracking.

Lysine methylation modulates diverse biological processes and is catalyzed by SET domain methyltransferases such as the SMYDs (SMYD1-5), which possess a SET domain split by a MYND motif. Through association with NCoR, the H4 Lys20 methyltransferase activity of SMYD5 represses inflammation by restricting TLR-4 mediated expression in macrophages, yet biochemical and structural features required for SMYD5 methylation activity remain elusive. To determine how SMYD5 catalyses methylation, crystallization screens were conducted with SMYD5 in complex with the co-factor AdoMet and histone H4. Screens yielded lead conditions but no crystals. To determine the motif recognized by SMYD5 and decipher its methylome, peptide arrays were conducted to produce a methylation motif used to identify putative substrates. Surprisingly, arrays revealed that substitution of Lys16, not Lys20, is detrimental to SMYD5 activity. Further enzymatic assays are required to determine if SMYD5 methylates residues other than Lys20 on the H4 tail, or if structural determinants or interacting partners restrict methylation of target lysines.

This thesis is a power generation study of a proposed CubeSat at Mississippi State University (MSU). CubeSats are miniaturized satellites of 10 x 10 x 10 cm in dimension. Their power source once in orbit is the sun during daylight and the batteries during eclipse. MSU CubeSat is equipped with solar panels. This effort will discuss two types of cells: Gallium Arsenide and Silicon; and which one will suit MSU CubeSat best. Once the cell type is chosen, another decision regarding the electrical power subsystem will be made. Solar array design can only be done once the choice of the electrical power subsystem and the solar cells is made. Then the power calculation for different mission durations will start along with the sizing of the solar arrays. In the last part the batteries are introduced and discussed in order to choose one type of batteries for MSU CubeSat.