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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

PARTICLE REPRESENTATIONS FOR FINITE GAP OPERATORS (BAKER-AKHIEZER).

SCHILLING, RANDOLPH JAMES. January 1982 (has links)
It is known that finite gap potentials of Hill's equation y" + q(τ)y = Ey can be obtained as solutions of an integrable dynamical system: uncoupled harmonic oscillators constrained to move on the unit sphere in configuration space--The Neumann System. This Dissertation systematizes and generalizes this result. First, the theory of Baker-Akhiezer functions is placed on a solid mathematical foundation. Guided by the theory of Baker-Akhiezer functions and Riemann surfaces, trace formulas, particle systems, constraints, integrals and Lax pairs are systematically constructed for the particle system of the ℓ x ℓ matrix differential operator of order n.
82

Heuristic search methods and cellular automata modelling for layout design

Hassan, Fadratul Hafinaz January 2013 (has links)
Spatial layout design must consider not only ease of movement for pedestrians under normal conditions, but also their safety in panic situations, such as an emergency evacuation in a theatre, stadium or hospital. Using pedestrian simulation statistics, the movement of crowds can be used to study the consequences of different spatial layouts. Previous works either create an optimal spatial arrangement or an optimal pedestrian circulation. They do not automatically optimise both problems simultaneously. Thus, the idea behind the research in this thesis is to achieve a vital architectural design goal by automatically producing an optimal spatial layout that will enable smooth pedestrian flow. The automated process developed here allows the rapid identification of layouts for large, complex, spatial layout problems. This is achieved by using Cellular Automata (CA) to model pedestrian simulation so that pedestrian flow can be explored at a microscopic level and designing a fitness function for heuristic search that maximises these pedestrian flow statistics in the CA simulation. An analysis of pedestrian flow statistics generated from feasible novel design solutions generated using the heuristic search techniques (hill climbing, simulated annealing and genetic algorithm style operators) is conducted. The statistics that are obtained from the pedestrian simulation is used to measure and analyse pedestrian flow behaviour. The analysis from the statistical results also provides the indication of the quality of the spatial layout design generated. The technique has shown promising results in finding acceptable solutions to this problem when incorporated with the pedestrian simulator when demonstrated on simulated and real-world layouts with real pedestrian data.
83

The Novels of Shirley Jackson: A Critical-Analytical Study

Ferguson, Mary G. 01 1900 (has links)
This study will discuss each of Shirley Jackson's six novels. The discussions will concentrate on plot, setting, theme, characterization, and style.
84

Wicked Words and Illegal Imaginings: A Genealogy of Obscenity In Which a Criminological Case Study of Fanny Hill Is Conducted

Piamonte, Stephanie 15 April 2019 (has links)
A genealogy of the concept of obscenity is conducted through a case study of John Cleland’s novel, "Memoirs of a Woman of Pleasure" (1748-1749), popularly known as "Fanny Hill". Analytic attention is focused on events (i.e. given moments in history characterized by struggle), discourses (i.e. systems of knowledge), and practices (i.e. institutional procedures), all of which are interrelated, and problematizes them with a moral regulation interpretive framework. This dissertation considers how "Fanny Hill" was (re)problematized as obscene through historically specific discursive practices, and how these discursive practices, conceived as the exercise of power in conjunction with systems of knowledge or as projects of moral regulation, had effects on the constitution of subjectivities and social orders. Further, this dissertation problematizes the ways that these discourses, practices and effects – particularly those pertaining to harm – continue into the present.
85

Mixed use building in Mission Hill.

Renner, Richard Kemp January 1976 (has links)
Thesis. 1976. M.Arch.--Massachusetts Institute of Technology. Dept. of Architecture. / Microfiche copy available in Archives and Rotch. / Bibliography: leaf 25. / M.Arch.
86

Genomic and phenotypic consequences of asexuality

Sharbrough, Joel 01 August 2016 (has links)
Sexual reproduction is expected to facilitate the removal of deleterious mutations from populations because biparental inheritance (i.e., segregation) and recombination during meiosis break down linkage disequilibria (LD), allowing mutations to be selected independently from their genetic background. Accordingly, the absence of recombination and segregation is expected to increase selective interference between loci, translating into reduced efficacy of natural selection. While there now exist multiple lines of evidence demonstrating that asexual lineages do experience accelerated accumulation of putatively harmful mutations, whether these mutations influence phenotype in a manner that could contribute to the maintenance of sex remains almost entirely unevaluated. Here, I use the New Zealand freshwater snail, Potamopyrgus antipodarum, to address these questions. In particular, I take advantage of the fact that the mitochondrial genome is expected to suffer from these mutational effects and interacts extensively with the nuclear genome to evaluate potential harmful effects of mutation accumulation in asexuals on a genome-wide scale. I present evidence that harmful mutations remain extant longer in asexual populations than in sexual populations, that the degree of functional constraint determines the extent of mutation accumulation in asexuals, that there is genetic variation for mitochondrial function in asexual lineages of P. antipodarum, and that phenotypic variation for mitochondrial function is mediated by both genetic and environmental variation. Together, these analyses provide strong evidence that asexual lineages are accumulating deleterious mutations, and that there is genetic variation, structured by lake, for mitochondrial function.
87

Local effects of limited recombination in Drosophila

Williford, Anna Ouzounian 01 May 2010 (has links)
Recent years have witnessed the integration of theoretical advances in population genetics with large-scale analyses of complete genomes. As a result, a growing number of studies suggest the frequent occurrence of deleterious as well as adaptive mutations. Given the evidence for the widespread occurrence of selection, the finite sizes of natural populations, and the limited recombination in every genome, mutations under selection are expected to alter the fate of genetically linked mutations. The consequences of this non-independent behavior of mutations can be described by the Hill-Robertson effect in terms of the reduction in the effective population size (Ne). Reduction in the effective population size has two effects: 1) a reduction in levels of genetic variation and 2) a reduction in the effectiveness of selection that is manifested in an increased probability of fixation of deleterious mutations and a reduced probability of fixation of advantageous mutations. Changes in Ne that have previously been frequently associated with changes in recombination rate can also occur locally, in association with changes in the number of sites under selection even when the recombination rate remains uniform. The main objective of the work presented in this thesis is to investigate these local effects of the non-independent behavior of mutations on patterns of polymorphism and divergence in Drosophila using computer simulation and experimental approaches. A computer simulation approach is developed to investigate the local consequences of linked selection on estimates of selection and the proportion of adaptive substitutions using the McDonald-Kreitman framework. The results suggest that even a high level of recombination is unlikely to remove all the effects of linked selection. Ignoring these local linkage effects leads to misleading estimates of the intensity of selection and the proportion of adaptive substitutions. Two predictions of the Hill-Robertson effect were tested empirically by examining patterns of polymorphism and divergence combined with codon bias estimates in genes with and without introns: 1) the effectiveness of selection and polymorphism levels are expected to be reduced in the center of the long coding sequence of genes without introns (the intragenic Hill-Robertson effect), and 2) introns are expected to function as modifiers of recombination thereby increasing the effectiveness of selection in the central region of the coding sequence of genes containing centrally located introns. The evidence from divergence and codon bias patterns in genes with a long coding sequence supports the presence of the intragenic Hill-Robertson effect. However, polymorphism levels do not show the expected decrease in the center of the coding sequence. With regard to the second prediction, results indicate that intron presence does not increase the effectiveness of selection at synonymous sites in the set of investigated genes. Rather, intron presence is associated with increased levels of adaptation at nonsynonymous sites. Further investigations are necessary to clarify the role of introns in mediating the increase in adaptation.
88

Petrology of Jurassic coal, Hill River area, Perth Basin, Western Australia

Suwarna, Nana January 1993 (has links)
The Early Jurassic coal samples for the study were obtained from CRA Exploration Pty Ltd. (CRAE), drilled in the Gairdner and Mintaja Blocks, Gairdner Range of the Hill River Area, northern Perth Basin, Western Australia. The area is located approximately 280 km north of Perth. The coal measures subcrop in a half- graben bounded by the Lesueur-Peron Fault in the west, and the Warradarge Fault in the east. The coal occurs within the shallow sequence of the Cattamarra Member which is also described as the Cattamarra Coal Measures of the Cockleshell Gully Formation.Six sub-seams of seam G, namely G1 to G6, from the six drill cores, were examined for petrological and geochemical investigation. The coal predominantly comprises of banded, dull banded, and dull lithotypes, with minor bright banded, bright and fusainous types. Based on maceral analyses, the dominant maceral groups are vitrinite and inertinite, whilst the exinite and mineral matter are in minor contents. The vitrinite content has a range between 47.2 % to 73.0 %, and it is composed mainly of telocollinite and desmocollinite. The inertinite is dominated by semifusinite, fusinite, and inertodetrinite, and it has a range from 10.4 % to 24.8 %. The exinite group varies between 7.2 % to 20.8 % in content, and it is represented by sporinite, cutinite, alginite and resinite. The mineral matter dominated by clays and pyrite, ranges between 4.5 % to 20.6 %. The microlithotype analyses shows that the vitrite plus clarite content varies from 47.0 % to 70.0 %, intermediates between 8.0% to 26.0 %, whilst inertite plus durite content is relatively low, varying from 6.55 % to 14.0 %. The maximum reflectance of vitrinite has a value between 0.47 % and 0.53 %, which represents rank at sub-bituminous level based on the Australian rank values and corresponding to the sub-bituminous A and B rank of the ASTM classification and ++ / to the metalignitous type of the Pareek classification. On the basis of carbon and hydrogen content, the coal is categorised as per-hydrous meta- to ortho-lignitous type. The trace elements As, B, Be, Cd, Co, Cr, Cu, Ga, Mn, Mo, Ni, Pb, Sr, Th, U, V, Y, Zn, and Zr, are spectrographically analysed in the coal ash. The B content in the coal supports the presence of marine influence during peat deposition in the basin.On the basis of lithotype, maceral, microlithotype, trace element distribution, pyrite and total sulphur in the coal, the depositional environment for coal and the coal measures, is interpreted as an upper to lower delta type within a regressive phase of marine transgression.
89

Soil Erosion Studies on Steep Slopes of Humid-Tropic Philippines

Presbitero, Alan Ludovice, n/a January 2003 (has links)
An in-situ water-induced soil erosion study of two years duration was conducted at a low slope of about 10%, and also on steep slopes of about 50%, 60% and 70% at the experimental site located at a soil and water research area contiguous to the Department of Agricultural Engineering and Applied Mathematics of the Visayas State College of Agriculture (ViSCA). ViSCA is located in the town of Baybay at the island of Leyte in humid tropical Philippines (latitude of 10 degrees 44' north and longitude of 124 degrees 48' east). The study has the following aims, namely: 1) to investigate the effect of local farming practices on soil erosion, particularly at steep slopes; 2) to study the hydrology and soil erosion processes in steep slope conditions in humid tropical climate; and 3) to apply and determine the limitations of a physical process-oriented sediment transport model for water-induced soil erosion model (Griffith University Erosion System Template, GUEST) to a very permeable soil under very high rainfall conditions. In the context of the steep slope experiments at ViSCA: a) across the slope planting of corn is equally effective in controlling soil loss as hedged farming alone or in combination with peanut intercrop; b) across the slope planting of corn in hedged runoff plots is as effective in controlling soil loss as when combined with peanut intercrop; c) farmer’s practice of planting a rowcrop like corn along the slope (providing ready-made downslope pathways for runoff water thus, encouraging flow-driven soil erosion) produces significant soil loss, often larger than from a bare runoff plot; d) hedgerows significantly reduced sediment concentration provided they remain intact; e) "failure" in hedgerows, often results in massive soil loss, being even greater than that in a comparable bare runoff plot. (Failure is manifested by runoff breaching the litter barrier at the base of the hedgerow in a localized position, leading to concentrated flow and extension of rills upslope from base of hedgerow) of hedged runoff plot (even though contour planted) and f) application of stubble in combination with across slope planting in hedged runoff plots (with or without a closely growing intercrop) provided both maximum surface cover (aerial and contact) and protection against soil loss in steep slopes. These conclusions are likely to apply to crops similar to corn, with an intercrop similar to peanut in morphology and root system. These conclusions might also be expected to apply to low slopes, though the effect of such protection might not be as pronounced as in steep slope runoff plots. Soil erosion mechanisms in steep slopes are dominated mainly by the runoff-driven processes of entrainment and re-entrainment. Average sediment concentration c and total soil loss M are shown to be functions of positive coefficient runoff related regressors and a parameter that measures rills formed and permanently imprinted on soil surface, and of negative coefficient regressors related to surface contact cover, at least for the steep slopes considered in this study. The relatively high streampower associated with overland flow on steep slopes suggests that overland flow dominates over rainfall impact as a source of soil sediment concentration. This was confirmed by the low value of the measured ratio of soil sediment concentration shed by net-rainfall detachment trays to that lost from the bare runoff plots. On the effect of surface contact cover on average sediment concentration c, the following findings were made, namely: a) surface contact cover of only about 20% to 30% is sufficient to reduce c to low levels, assuming the cover is well distributed; b) an "exponential-decay" form of relationship existed between surface contact cover and the average sediment concentration from the non-bare soil without normalizing with respect to sediment concentration from a reference bare soil runoff plot; and c) such nonlinear relationship is indicative of the dominating runoff processes of entrainment and re-entrainment compared to the linear form of relationships if rainfall –driven processes of detachment and re-detachment dominate. In runoff dominated soil erosion processes, surface contact cover (including both living and dead vegetative cover close enough to the soil surface to impede overland flow) is more significant in curtailing soil erosion than aerial surface cover. ...continued.
90

Using site as the medium of image-making at Tower Hill.

Stretch, Eleanor Eunice, mikewood@deakin.edu.au January 2000 (has links)
[No Abstract]

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