Thesis (Ph.D.)--Hong Kong University of Science and Technology, 2006. / Vita. Includes bibliographical references (leaves 119-133). Also available in electronic version.

This study is a contribution to the growing literature on the subject of the role of education in national reconstruction and reconciliation in countries that have experienced conflict and severe dislocation. It takes as its focus the case of Zimbabwe during the period 1980-2010 but related to experiences of conflict in countries such as Angola, Liberia, Mozambique, Sierra Leone, Somalia, the Sudan and Rwanda in Africa and, elsewhere, in Bosnia, Iraq, Israel, Palestine, Lebanon and Northern Ireland.

No description available.

No description available.

Statistical methods for approaching image reconstruction and restoration problems have generated much interest among statisticians in the past decade. In this dissertation, we examine in detail various statistical methods of image reconstruction through the simulation of a multiple-pinhole coded-aperture imaging system for use in emission tomography. We reconstruct each object from a class of 64 total objects, obtaining a reconstruction for each of the 64 originals by several different methods. Among the methods that we use to obtain these reconstructions are maximum likelihood techniques, where we make use of both the popular expectation-maximization (EM) algorithm and a Monte Carlo search routine. We also examine methods that include, in some form, various kinds of prior information. One way of using prior information is through the specification of a prior probability density on the object (or class of objects) to be reconstructed. We investigate the use of Markov random field (MRF) models as a means of specifying the prior densities that will be used to obtain reconstructions. Once given a prior density, these reconstructions are taken to be approximations to the maximum a posteriori (MAP) estimate of the original object. We also investigate reconstructions obtained through other prior densities plus reconstructions obtained by introducing prior information in alternate ways. Once all the reconstructions are obtained, we attempt to answer the important question, "which reconstruction method is 'best'?" We define "best" in this context to be the method that allows a human observer to perform a specified task the most accurately. The task to be performed is to determine whether or not a small protrusion exists on an elliptical object. (This task is motivated by the desire to detect wall-motion abnormalities in the left ventricle of the heart.) We generate 32 objects with protrusions (abnormal objects) and 32 objects without protrusions (normal objects). These objects constitute our class of 64 originals which are reconstructed by the various methods. The reconstruction methods are then analyzed through receiver operating characteristic (ROC) analysis, and a performance index, the area under the curve (AUC), is obtained for each method. Statistical tests are then performed on certain pairs of methods so that the hypothesis that no difference between the AUC's exists can be tested. We found that the reconstruction methods that used the largest amount of (accurate) prior information were generally superior to other methods considered. We also compute calculable figures of merit (FOM) associated with each reconstruction method with the hope that these FOM's will predict the performance of the human observer. Unfortunately, our results indicate that the FOM's that we considered do not correlate well with the performance of the human.

Having constructed a plantation economy in the Yazoo Mississippi Delta, white Delta planters struggled to retain control of African-American labor after the start of the Civil War. In their effort, the planters manipulated the Freedmen's Bureau; passed the Black Code; sought out foreign labor; and condoned extralegal intimidation. The Civil War disrupted the plantation economy of the Yazoo Delta, prompting the planters to pursue innovative means to preserve the status quo. To achieve this end, they fought with the Confederate government for control of the militia, attempting to stabilize an economy rocked by military incursions, deserters, and outbreaks of lawlessness. Emancipation, the ultimate disruption to the plantation, precipitated a struggle between these former masters and African-Americans seeking to find the meaning of their freedom. The United States government also attempted to restructure the plantation economy of the Delta after the Civil War, but planters often manipulated federal authority to their advantage. Charged with protecting the interests of the freedmen, the Freedmen's Bureau, for example, frequently accommodated the labor needs of Delta planters, even transporting labor to the plantations when necessary. Similarly, Union military commanders frequently supported the planters in their attempt to control black labor. Delta planters, however, wished themselves entirely free of outside governance. Thus, in 1865, they helped formulate the Black Code, seeking to limit the labor options of the freedmen. When Congress negated this code, the planters sought foreign laborers to force African-Americans into economic desperation. Under congressional patronage, moderate Republicans, led by Delta planter James L. Alcorn, attempted to build a party led by white men and supported by African-American votes. When this moderate "Alcorn Republican" system failed in 1873, the planters aligned themselves with the "straight out" Democratic party, rather than support the pro-black Republicans led by Adelbert Ames. Using a system of fraud and brute violence, the white planters ultimately seized power from the Republican party in 1875. This "Mississippi Plan" allowed the planters to remove labor from politics, free the state from authority inimical to their interests, and ensure continuation of the plantation economy.

No description available.

No description available.

No description available.

Positron Emission Tomography (PET) images reconstructed without adequate scatter corrections introduce noise and degrade image contrast. In commercial imaging systems, misalignment between computed tomography (CT) and PET images can introduce biases in the activity distribution. Recently, several reconstruction algorithms have been proposed, which made direct use of single scattered photons in the activity reconstruction. However, the realistic dataset contains single and higher order scattered photons, and current scatter reconstruction methods do not distinguish them. In this study, a novel reconstruction algorithm that is capable of processing higher order scattered photons was developed. A restricted attenuation correction method was created to avoid overcorrecting for scattered photons. The simulation outcomes have shown that the proposed methods can, under ideal energy resolution, reconstruct images that are qualitatively and quantitatively better than those obtained using existing algorithms, and that the methods show promise for use under more realistic clinical conditions. / October 2016