81,287 research outputs found

    Differentiating the effects of negative state on optimism and the implicit perception of everyday injury risk

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    To date no research has examined the effects of negative state on the perception of everyday injury risk. Instead, studies have focussed more broadly on the relationship between mood and self- reported optimism. The present study had two aims. Firstly, to assess the effect of incidental anxiety on implicit injury risk perception using a modified Implicit Association Test (IAT). Secondly, it sought to compare any effect with that on a conventional measure of risk perception (optimism). In line with previous research, anxious participants perceived more risk (were less optimistic). In contrast, there was no significant correlation between anxiety and the implicit perception of everyday injury risk. Theoretical and practical implications are discussed

    Swarm keeping strategies for spacecraft under J2 and atmospheric drag perturbations

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    This thesis presents several new open-loop guidance methods for spacecraft swarms comprised of hundreds to thousands of agents with each spacecraft having modest capabilities. These methods have three main goals: preventing relative drift of the swarm, preventing collisions within the swarm, and minimizing the fuel used throughout the mission. The development of these methods progresses by eliminating drift using the Hill-Clohessy-Wiltshire equations, removing drift due to nonlinearity, and minimizing the J2J_2 drift. In order to verify these guidance methods, a new dynamic model for the relative motion of spacecraft is developed. These dynamics are exact and include the two main disturbances for spacecraft in Low Earth Orbit (LEO), J2J_2 and atmospheric drag. Using this dynamic model, numerical simulations are provided at each step to show the effectiveness of each method and to see where improvements can be made. The main result is a set of initial conditions for each spacecraft in the swarm which provides hundreds of collision-free orbits in the presence of J2J_2. Finally, a multi-burn strategy is developed in order to provide hundreds of collision free orbits under the influence of atmospheric drag. This last method works by enforcing the initial conditions multiple times throughout the mission thereby providing collision free motion for the duration of the mission

    The Small Watershed Program

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    Idealism and materialism in antebellum southern political history : a review essay

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    Although the mainstream "new political historians" have largely ignored the South, historians of the antebellum South have produced some of the most interesting recent works in political history. These scholars fall into two groups: one finds a white consensus, emphasizes ideology, and concentrates on evidence from "literary" sources; the other discovers evidence of conflict, stresses the material basis of political alignments, and combines quantitative with traditional evidence. In a brief review of books by Channing and Johnson, I point out that by concentrating on the immediate pre-war years, the authors cannot answer even the questions they themselves pose. Cooper's 1978 ideological interpretation finesses the question of the connection between opinions on slavery and Unionism and fails to explain why the southerners' responses to the crises of 1850 and 1860 were so different. The central work of the last two decades, Thornton's, presents the bold and complex thesis that the South was born libertarian and avoids many of the problems of the other works reviewed. His treatment of politics-as largely symbolic-expressive, rather than rational instrumental, and his lack of statistical sophistication, however, invite criticism. The most valuable facet of these works for American political history generally is that they restore politicians, policy, and political thought -- topics often shunted aside by the social history approach of the past generation -- to the study of politics

    "Power to the people?" : the Palmerston North Municipal Electricity Department, 1910-1996 : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in History at Massey University

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    The impetus for this study came from my interest and contacts in the energy sector, allied to a desire to advance local history writing from a mere reporting of events. Therefore, this thesis attempts to place a local Manawatu organisation into a national context to analyse the significance of its activities. The Palmerston North MED was chosen for this study because the records were preserved in the Palmerston North City Council Archives and were thus available for use, and because of my contacts with the organisation. It was stimulating to study an enterprise up to the present day, although this has provided some difficulties with obtaining confidential material at a time when the Council was considering merging it with a power board. In the course of this thesis many people have provided a great deal of assistance. Firstly, I would like to thank my supervisors, Dr James Watson and Professor Kerry Howe, for their support, guidance and comments. The Massey University History Department provided financial assistance, as did the Massey University Graduate Research Fund and Federation of University Women (Manawatu Branch), without which completion of my work would have been difficult. I also appreciated the general support and interest of individual members of the History Department. Ian Matheson and Barbara Olsen of the Palmerston North City Council Archives provided access to material relating to the Palmerston North Municipal Electricity Department, assisted with locating pictures, and unfailingly answered my questions. I am grateful that the City has such a resource available for students and historians. The records staff of the Palmerston North City Council also provided access to current records, for which I am appreciative. I would also like to thank the staff of Electro Power for allowing me to base my researches in their office temporarily, for answering technical questions and explaining photographs, and for displaying interest in my findings. Many of the photographs used come from the Electro Power collection. Lastly, I could not have completed this thesis without the assistance of Sheryl Morgan, discussions with Jim Lundy, and the moral support of my fellow Masters students. My biggest debt, however, is to the support, technical assistance and enthusiasm of Terry Jones, and for this I thank him
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