34,497 research outputs found
An empirical model of long-term thermospheric density change
No full textPredicting the positions of satellites in Low Earth Orbit (LEO) requires a comprehensive understanding of the dynamic nature of the atmosphere. For objects in LEO the most significant orbit perturbation is atmospheric drag, which is a function of the local atmospheric density from a layer in the atmosphere called the thermosphere. For long-term predictions of satellite orbits and ephemerides, any density trend in the thermosphere is a necessary consideration, not only for satellite operators, but also for studies of the future LEO environment in terms of space debris. Numerous studies of long-term thermospheric density change have been performed.Predictions by Roble & Ramesh (2002), along with evidence by Keating (2000), Emmert et al.(2004), Marcos et al. (2005), Qian et al. (2006) and Emmert et al. (2008), strongly suggest the existence of such a phenomenon. Therefore, the objective of the research presented in this thesis is to provide a novel method to evaluate quantitatively thermospheric density change. Satellite drag data is an effective medium through which one can investigate local thermospheric density and changes thereof. There are many ways of determining atmospheric density, but inferring thermospheric density from satellite drag data is a relatively cost-effective way of gathering in-situ measurements. To do this, knowledge about a satellite’s physical properties that are intrinsic to atmospheric drag is required. A study by Saunders et al. (2009) highlighted problems with estimating a satellite’s physical properties directly from data given explicitly by Two-Line Element (TLE) sets. This prompted an investigation into ways to estimate ballistic coefficients: a required satellite parameter associated with drag coefficient and area-to-mass ratio. A novel way of estimating satellite ballistic coefficients was derived and is presented in this thesis. Additionally, novel consideration of atmospheric chemical composition was applied on long-term drag coefficient variability. Using a quantitative estimate of a ballistic coefficient one can propagate numerically a satellite’s orbit and predict the effects of atmospheric drag. Given an initial satellite orbit from TLE data, one approach is to use an orbital propagator to predict the satellite’s state at some time ahead and then to compare that state with TLE data at the same epoch. The difference between the semi-major axes of the initial orbit and that after the orbit propagation is then integrated and can be used to estimate the global average density. The method employed in this study utilises this process. To achieve this, a specially developed, computer-based, numerical orbital propagator was written in the programming language C/C++. The underlying theories and implementation tests for this propagator are presented in this thesis
Exploring Emptiness: An Investigation of MA and MU in My Sonic Composition Practice
No full textThe commentary investigates Japanese aesthetics of space, silence and emptiness - ma and mu - that informed my compositional practice during the research period 2012 - 2015. The portfolio comprises text compositions and sound installations in which forms of micro events and sustained events are employed. Throughout, the emphasis is on my personal engagement with, and manifestation of emptiness that concerns a particular model of listening and perception.
Chapter 1 discusses six primary research areas: ma and mu, material, text, form, listening and perception. Firstly, I introduce ma and mu by examining noh culture and Zeami's teaching of senu hima (where there is no-action) in the context of my personal approaches to music. The following subjects are then used to contextualise my PhD practice by means of examples from various composers and visual artists. Here, these particular and enigmatic concepts are explored through Japanese art as well as Western contemporary works by Alvin Lucier, Eliane Radigue and those of the Wandelweiser collective.
Part 2 provides contextual commentaries on selected compositions from the portfolio that mostly articulate my aesthetics in relation to the topics covered in Chapter 1. koso koso addresses my methodologies to investigate the essence of senu hima, followed by treow that discusses my approach to materials and the importance of space. I move on to grade two and grade two extended in order to examine text scores, and then, look into Espèces d'espaces 03 and 04 as examples of musical forms that I employ.
Finally, listening and perception are investigated through the compositions gnome and con.de.structuring. Throughout, I describe how my works explore emptiness as a result of my particular emphasis on listening over composing
Agrilus parvus Saunders 1870
No full textA. parvus Saunders : MA: Essex Co., Otis 2015-MA-607- HP: 42.6133 N, 71.0691 W, 4-viii-2015 (1), MD: Washington Co., Otis 2013-MD-5683: 39.606 N, 78.0104 W, 20-vi-2013 (1).Published as part of Barringer, Lawrence, 2020, New records of woodboring beetles (Coleoptera: Buprestidae) for the eastern United States, pp. 1-25 in Insecta Mundi 746 on page 4, DOI: 10.5281/zenodo.369394
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Agrilus lecontei Saunders
No full text<p> <b> <i>A. lecontei</i> Saunders</b> : <b>MA</b>: Plymouth Co., Otis 2014-MA-206- Soule: 41.9323 N, 70.8393 W, 9-vii-2014 (1).</p>Published as part of <i>Barringer, Lawrence, 2020, New records of woodboring beetles (Coleoptera: Buprestidae) for the eastern United States, pp. 1-25 in Insecta Mundi 746</i> on page 4, DOI: <a href="http://zenodo.org/record/3693943">10.5281/zenodo.3693943</a>
The majority of genes in the pathogenic Neisseria species are present in non-pathogenic Neisseria lactamica, including those designated as 'virulence genes'
No full textThis is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited - © 2006 Snyder and Saunders; licensee BioMed Central Ltd.Background: Neisseria meningitidis causes the life-threatening diseases meningococcal meningitis and meningococcal septicemia. Neisseria gonorrhoeae is closely related to the meningococcus, but is the cause of the very different infection, gonorrhea. A number of genes have been implicated in the virulence of these related yet distinct pathogens, but the genes that define and differentiate the species and their behaviours have not been established. Further, a related species, Neisseria lactamica is not associated with either type of infection in normally healthy people, and lives as a harmless commensal. We have determined which of the genes so far identified in the genome sequences of the pathogens are also present in this non-pathogenic related species. Results: Thirteen unrelated strains of N. lactamica were investigated using comparative genome hybridization to the pan-Neisseria microarray-v2, which contains 2845 unique gene probes. The presence of 127 'virulence genes' was specifically addressed; of these 85 are present in N. lactamica. Of the remaining 42 'virulence genes' only 11 are present in all four of the sequenced pathogenic Neisseria. Conclusion: Assessment of the complete dataset revealed that the vast majority of genes present in the pathogens are also present in N. lactamica. Of the 1,473 probes to genes shared by all four pathogenic genome sequences, 1,373 hybridize to N. lactamica. These shared genes cannot include genes that are necessary and sufficient for the virulence of the pathogens, since N. lactamica does not share this behaviour. This provides an essential context for the interpretation of gene complement studies of the pathogens.This study is supported by the Wellcome Trust
A Decision-Making Model for Industrial Development
No full textTitle: A Decision-Making Model for Industrial Development, Author: M. J. Saunders, Location: ThodeStudies of industrial location decision-making and the construction
of decision-making models to date have invariably been
couched in behavioural terms.1 Likewise the majority, if not all of
such empirical studies have centred on the industrialist as the decision-
maker, on the assumption that, because he has made a location
decision, he necessarily knows how best to do so. Little or no attention
has been paid to the legislative structures within which
industrial location decisions must be made, or to the part played by
the elected representatives who are responsible for making such decisions.
This paper is an attempt to escape from the behavioural habit
by developing a structural model for industrial location and development
decision-making at the community level.ThesisMaster of Arts (MA
Power Birnbaum-Saunders Student t distribution
No full textLa distribución de probabilidad propuesta por Birnbaum y Sa un- ders se ha usado con bastante eficacia para modelar tiempos de falla de ma- teriales sujetos a la fátiga. En este artículo definimos una e xtensión de la distribución Birnbaum-Saunders clásica sustituyendo la d istribución normal por la distribución potencia t de Student. La nueva distribución es más flexi- ble que la distribución Birnbaum-Saunders clásica en térmi nos de asimetría y curtosis. Presentamos los estimadores de máxima verosimi litud de los pa- rámetros del modelo y su modelo de regresión asociado. El aná lisis de dos aplicaciones con datos reales revelan una superioridad del nuevo modelo con relación a otros modelos existentes en la literatura
The role of Umkhonto we Sizwe (MK) in the national liberation struggle in South Africa with reference to the rural far northern Transvaal, 1976-1990
No full textIncludes bibliographical references (leaves 250-275)
The construction of Karen Karnak: The multi-author-function
No full textThis thesis is situated within the comparatively recent developments of Web 2.0 and the emergence of interactive WikiMedia, and explores the mode of authorship within a Read/Write culture compared to that of a Read/Only tradition. The hypothesis of this study is that the role of the audience has become merged with the author, and as such, represents new functions and attributes, distinct from a more conventional concept of authorship, in which the roles of audience and author are more separate. Read/Write and participatory culture, as defined by this study, is focused on collaboration, and includes the influences of D.I.Y. culture, Open-Source practices and the production of text by multiple authors. Multi-authorship presents a re-thinking of several concepts which support the notion of the individual author, since the focus of multi-authorship is not on attribution and ownership of a finished text, but on the continued malleability of a text. Modes of multi-authorship, demonstrated in the use of the pseudonyms Alan Smithee and Karen Eliot, represent declarative authors whose names signify multiple origins, whilst concurrently indicating a distinct body of work. The function of these names form an important context to this study, since primary research involves the construction of an experimental mode of multi-authorship utilising WikiMedia technology and the interaction of thirty nine participants, who are invited to create a body of work under the collective pseudonym Karen Karnak. The data generated by this experiment is analysed using aspects of Michel Foucault's author-function to identify and determine power structures inherent in the WikiMedia context. The interplay of power structures, including concepts such as identity, ownership and the body of work, affect the resulting mode of authorship and contribute to the construction of Karen Karnak, suggesting further areas of research into the emerging multi-author
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