107 research outputs found
Putting the pieces together: the systematic development of a software defined radio toolflow for the Rhino project
No full textThis dissertation is concerned with the thesis that it is possible for a software defined radio system that has been described in accordance with synchronous data flow theory to be implemented upon a reconfigurable computing platform
Optimal Sampling for Single-Tone Frequency Estimation
No full textSingle-tone frequency estimation from irregularly spaced samples is analyzed. The ratio of the Cramr-Rao Bound (CRB) for regularly spaced samples to the bound for irregularly spaced samples is presented and shown to be a globally convex function. It\u27s minima and maxima over the domain of interest are identified which reveals that improvements in the CRB can be obtained using non-equally-spaced samples. For a given sampling density, the best estimates of frequency are obtained when half of the samples are taken at one end of the total available interval and the remaining samples are taken at the other end
A Bayesian perspective on estimating mean, variance, and standard-deviation from data
No full textThis article shows how to compute confidence intervals for mean, standard-deviation, and variance using Bayesian methods. The method is implemented in SciPy as scipy.stats.bayes_mvs After reviewing some classical estimators for mean, variance, and standard-deviation and showing that un-biased estimates are not usually desirable, a Bayesian perspective is employed to determine what is known about mean, variance, and standard deviation given only that a data set in-fact has a common mean and variance. Maximum-entropy is used to argue that the likelihood function in this situation should be the same as if the data were independent and identically distributed Gaussian. A non-informative prior is derived for the mean and variance and Bayes rule is used to compute the posterior Probability Density Function (PDF) of \left(\mu,\sigma\right) as well as \left(\mu,\sigma^{2}\right) in terms of the sufficient statistics \bar{x}=\frac{1}{n}\sum_{i}x_{i} and C=\frac{1}{n}\sum_{i}\left(x_{i}-\bar{x}\right)^{2}. From the joint distribution marginals are determined. It is shown that \left(\frac{\mu-\bar{x}}{\sqrt{C}}\right)\sqrt{n-1} is distributed as Student-t with n-1 degrees of freedom, \sigma\sqrt{\frac{2}{nC}} is distributed as generalized-gamma with c=-2 and a=\frac{n-1}{2}, and \sigma^{2}\frac{2}{nC} is distributed as inverted-gamma with a=\frac{n-1}{2}. It is suggested to report the mean of these distributions as the estimate (or the peak if n is too small for the mean to be defined) and a confidence interval surrounding the median
Incorporating DNA Sequencing into Current Prenatal Screening Practice for Down's Syndrome
No full textPMCID: PMC3604109This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Relocation Custody Disputes - A Binuclear Family-Centered Three-Stage Solution
No full textThis article argues that the best method for courts to adopt during relocation custody disputes is a binuclear, family-centered process. A binuclear family is defined as a large, interconnected family, with one household headed by the ex-wife and the other by the ex-husband, with the child being a member of both. The author contends that the current methods, which include the endangerment standard and the new family theory, are both inadequate to deal with a relocation custody dispute. Specifically, the author discusses a proposed three-step process for dealing with a relocation custody dispute. Step one involves the creation of a parenting plan, step two requires mediation and, as a last resort, step three would involve a de novo hearing by the court. This three-step process, following a binuclear family-centered approach, would make relocation disputes seem fair to all parties, and would avoid many of the current problems associated with the other methods of resolution
MRI RF Receiver and Transmitter Design
No full textRadiofrequency (RF) transmitters and receivers are a critical component in Magnetic Resonance Imaging (MRI). These are the components used for imaging. The goal of this project was to design an RF transmitter and receiver. Both were successfully designed and implemented
The reading of Newton in the early eighteenth century : Tories and Newtonianism
No full textThis dissertation examines Tory High-Church and Jacobite Episcopalian responses to Newton in early eighteenth century England and Scotland, providing a systematic analysis of the relationship between Newtonian natural philosophy, politics and religion from a Tory High-Church perspective. I argue that historical understanding of the linkages between political/ religious groups and Newtonian
natural philosophy in the early eighteenth century can be improved by extending current historical debate beyond existing scholarship on the politics of Newtonianism - scholarship which has sought to establish a close relationship between Whigs, Latitudinarians and support for Newton. Instead of assuming a fixed association between political and religious groups and support for Newton,
this thesis illustrates the multi-faceted nature of Newtonianism and the diverse political and religious uses to which Newtonian natural philosophy could be put. Tories and Jacobites frequently used Newton's science in political and religious debate to defend Tory High-Anglicanism and Scottish Episcopalianism, in spite of the numerous examples of Tory High-Church natural philosophers who saw Newton and his followers as exponents for radical Whiggery and heterodox thought, especially anti-Trinitarianism. This thesis seeks to understand how and why Tories and Jacobites had these various and often conflicting opinions of
Newton. By doing so more complex and thorough knowledge of the support and opposition to Newton during this period can be gained, along with a better historical understanding of the triumph of Newtonian natural philosophy over rival philosophical systems
Hyperbolic structures on 3-manifolds via volume maximization
No full textL'argomento di questa tesi è il problema di dare una struttura iperbolica (completa e di volume finito) a una 3-varietà.
Nel primo capitolo sono richiamati i risultati di geometria iperbolica utilizzati nel seguito.
Nel secondo capitolo è descritto il metodo introdotto da Thurston negli anni '70 per dare strutture iperboliche alle 3-varietà con cuspidi, tramite le equazioni di incollamento di Thurston, insieme ad una versione modificata di Casson, degli anni '90, in cui la struttura iperbolica viene ricavata cercando i punti di massimo del volume per delle strutture ad angoli euclidee.
Nel terzo capitolo sono riportati i due approcci noti per il caso delle varietà chiuse: quello di Manning, del 2002 (solo accennato), e quello di Luo, Tillman e Yang, del 2010. Quest'ultimo sfrutta il fatto che è possibile ottenere una struttura iperbolica a partire da una soluzione di volume massimo delle equazioni di Thurston algebriche (simili alle equazioni di incollamento).
Sia su varietà chiuse che con cuspidi sono definite delle "equazioni di Thurston": nel quarto capitolo è esposto un tentativo, di Luo ed altri autori, di generalizzare alcune di queste idee per triangolazioni di pseudovarietà. Su una pseudovarietà sono definite le equazioni di Thurston algebriche e le strutture ad angoli a valori in S¹. Su queste ultime è definito un volume, ed i punti di massimo danno origine:
* se lisci, a soluzioni delle equazioni di Thurston algebriche generalizzate;
* se non lisci, a soluzioni particolarmente semplici dell'equazione delle superfici normali.
Ho implementato in Python delle funzioni che permettono di trattare strutture ad angoli e equazioni di Thurston; nel quinto capitolo sono presenti degli esempi di calcolo, e in appendice è riportato il codice sorgente
Estimation of Complex-Valued Stiffness Using Acoustic Waves Measured with Magnetic Resonance
No full textMultiple arenas and professional identity : locating and defining the professionalism and accountabilities of the teacher educators in Lesotho
No full textIncludes abstract.Includes bibliographical references (leaves 273-288).Challenged by the granting of institutional autonomy to his institution - the Lesotho National Teachers Training College (now Lesotho College of Education) - the author explores the professional identities of teacher educators in Lesotho. Considering and analysing Lesotho's socio-political historical and institutional contexts of teacher preparation from a postcolonial perspective, he argues that very many factors circumscribe education, in general, and teacher education in particular in Lesotho. Autonomy from the state could therefore mean subjection of the college to these other factors. The socio-political history of Lesotho, chiefly its doublecolonisation through French missionary social and cultural sectarian subjection and British political and economic subjugation, renders it a highly heterogeneous society in subtle and subterraneous ways
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