Cost Adaptation for Robust Decentralized Swarm Behaviour

Decentralized receding horizon control (D-RHC) provides a mechanism for coordination in multi-agent settings without a centralized command center. However, combining a set of different goals, costs, and constraints to form an efficient optimization objective for D-RHC can be difficult. To allay this problem, we use a meta-learning process -- cost adaptation -- which generates the optimization objective for D-RHC to solve based on a set of human-generated priors (cost and constraint functions) and an auxiliary heuristic. We use this adaptive D-RHC method for control of mesh-networked swarm agents. This formulation allows a wide range of tasks to be encoded and can account for network delays, heterogeneous capabilities, and increasingly large swarms through the adaptation mechanism. We leverage the Unity3D game engine to build a simulator capable of introducing artificial networking failures and delays in the swarm. Using the simulator we validate our method on an example coordinated exploration task. We demonstrate that cost adaptation allows for more efficient and safer task completion under varying environment conditions and increasingly large swarm sizes. We release our simulator and code to the community for future work.Comment: Accepted to IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 201

Housing, the Capabilities Approach and Life Satisfaction

This thesis examines the relationships between housing, housing satisfaction and quality of life using the capabilities approach developed by Sen and others as a theoretical framework. This approach is used to engage with housing-related themes and as a way of thinking about how housing contributes to quality of life. It also analyses the scope for heterogeneity in these relationships by looking at the housing experiences of migrant communities in Western Europe and the Irish Traveller community. Despite, the growth of interest in the capabilities approach as a way of structuring social science and policy analysis, there is relatively little substantial research that applies the capabilities approach to housing. This is surprising in view of the fact that the neighbourhood in which a person lives and other characteristics of their housing are likely to be associated with their experienced quality of life as well as the opportunities a person has, objectively speaking. Consequently, this thesis is an attempt to address this gap by applying the capabilities approach to the field of housing research. The thesis is divided into four substantive chapters, each one dealing with a specific aspect of the relationship between housing, housing satisfaction and quality of life. Chapter 2 sets the scene for this study by presenting the results of a critical, broad-based review and summary of the literature with regard to housing, happiness and capabilities. The following chapters build on the foregoing in an empirical context; Chapters 3 and 4 do so primarily with quantitative analyses and Chapter 5 uses a mixed-methods approach including offering some original qualitative research. Chapter 6 summarises what has been achieved and the main contribution of the thesis whilst offering some remarks regarding what might be done in future research and the policy implications of these findings

Special Topic: Raven Management

This is the call for papers for the special issue on raven management

The South African Library as a state-aided national library in the era of apartheid : an administrative history

The Public Library in Cape Town was founded in the earliest days of British civil rule in Southern Africa, as a Government-funded free library of reference with the purpose of educating and enculturating the 'youth' of the Cape Colony along European (especially English) lines. Government funding being withdrawn in 1829, the Library became an autonomous subscription library while continuing to provide access to its reference collections free of charge. During the ensuing 125 years the Library (known as the South African (Public) Library) becameincreasingly dependenton Government financial aid to provide certain 'national' functions. By 1954 it was the pre-eminent research library in sub-Saharan Africa and enjoyed total autonomy within the limits of its 1893 Act of the former Cape Colonial Parliament. This study follows the transformation of the South African Library into a Stateaided national library after it had divested itself of its local circulating services in 1955 and its subsequent existence with limited autonomy and increasing financial difficulties. During the transformation process, the National Party came into office in 1948 and introduced its authoritarian, centralizing style of administration. Many of the new Government's policies conflicted with the ethos and practices of the South African Library, particularly the promotion ofWhite Afrikaner culture in the place of the Library's generally White Anglophile culture, and the implementation of racial policies in the place of the Library's non-racialism. By the time the implications of National Party 'apartheid' policies became evident, it was too late for the Library to revert to its previous state. The scope of this administrative history of the Library in this era is limited to an analysis of themes which illuminate the relationship between the State, the Library, the Library's users, and the library profession at large during the development and eventual downfall in 1994 of National Party rule. The central themes are the Library's struggle to retain maximum professional autonomy in the context of its almost total dependence upon the State for its funding; the degree of State funding being determined by Government's perception of the Library's legitimacy and contribution to its policy priorities. Despite providing distinguished services to research (both formal and informal), especially in the humanities, and having perhaps the best collection in the country of published and manuscript material relating to Southern Africa, the South African Library was unable to attract the funding needed to sustain its rapidly growing collections and overwhelming amount of use. When the National Party left office in 1994, the Library was already on the point of financial collapse, and the incoming African National Congress Government had more pressing priorities. The South African Library failed, and in 1999, together with the State Library in Pretoria (which was itself in difficulties), became part of the National Library of South Africa in a development which, fifteen years later, must still be considered a compromise. Since the author considers the two-site compromise to be unsustainable, the study concludes with a review of various proposals which were put forward by library professionals between 1955 and 1994 which may profitably be revisited. The research was based on documentary records in the extensive administrative archive of the South African Library. This has been supplemented from published sources and recollections of the author and former colleagues

Feral Horses Disrupt Greater Sage-Grouse Lekking Activity in the Great Basin

Greater sage-grouse (Centrocercus urophasianus; hereafter, sage grouse) and feral horses (Equus ferus caballus) co-occur within Great Basin sagebrush ecosystems of western North America. In recent decades, sage-grouse populations have declined substantially while concomitantly feral horse populations have increased drastically. Although multiple studies have reported feral horses adversely impacting native ungulate species, direct interactions between feral horses and sage-grouse have not been documented previously. We compiled sage-grouse lek count data and associated ungulate observations from 2010 and 2013-2018. We used Bayesian multinomial logistic models to examine the response of breeding male sage-grouse to presence of native (i.e. mule deer, pronghorn) and non-native (i.e. cattle, feral horses) ungulates on active sage grouse leks (traditional breeding grounds). We found sage-grouse were 9.5 times more likely to be present on active leks concurrent with native ungulates compared to non-native ungulates. Of the four different ungulate species, sage-grouse were least likely to be at active leks when feral horses were present. Our results suggest that the presence of feral horses negatively influences sage-grouse lekking activity. Because sage-grouse population growth is sensitive to breeding success, disruption of leks by feral horses could reduce breeding opportunities and limit breeding areas within sage-grouse habitat

Links between cyclotomic and GL2 Iwasawa theory

We study, in the case of ordinary primes, some connections between the GL2 and cyclotomic Iwasawa theory of an elliptic curve without complex multiplication

Women’s experiences of coping with the sexual side effects of antidepressant medication

A growing body of evidence has highlighted the sexual side effects of selective serotonin reuptake inhibitor (SSRI) medication. Whilst most of the research has focused on the prevalence and treatment of sexual difficulties, little is known about how patients cope with the SSRI-related sexual side effects. The objective of this study was to explore women’s experiences of coping with the sexual side effects of SSRI medication and interpretative phenomenological analysis was employed for an in-depth exploratory study of a sample of 10 women. Four broad themes emerged which are discussed under the following headings: searching, suffering in silence, trying to resolve and accepting what is. The themes provide an insight into the different strategies used by women to cope with the sexual side effects of SSRI medication and highlight the importance of contextualising these difficulties as part of an overall approach to improve the management and treatment of SSRI-related sexual side effects

Cape Colonial parliamentary publications, 1854-1910 : with special reference to documents in the Dutch language

This is a study of official documents published by and for the Cape colonial Parliament from the mid nineteenth century, when the parliamentary system of government began in South Africa, to the early years of the twentieth century, when the Cape colony was incorporated into the Union of South Africa. The constitutional framework within which government and parliamentary publishing took place is outlined, and the relevance of each type of document to the work of Parliament and the present-day researcher is explained. Emphasis has been placed on the administration of the publishing process from conceptualization through the printing stages to distribution and finally to the disposal of surplus material. The study concludes with an investigation of the current status of Cape parliamentary publications respecting preservation issues and the exploitation of the material for research purposes in libraries and archives, and some remarks on future trends. Particular attention has been given to use of the Dutch language in the predominantly English language Cape Parliament and the hitherto neglected effect this had on official publishing. Copious footnotes and seven appendixes have been supplied to make this study thoroughly comprehensive.Information ScienceM.Info. (Information Science