Logical presentations of domains

Bibliography: pages 168-174.This thesis combines a fairly general overview of domain theory with a detailed examination of recent work which establishes a connection between domain theory and logic. To start with, the theory of domains is developed with such issues as the semantics of recursion and iteration; the solution of recursive domain equations; and non-determinism in mind. In this way, a reasonably comprehensive account of domains, as ordered sets, is given. The topological dimension of domain theory is then revealed, and the logical insights gained by regarding domains as topological spaces are emphasised. These logical insights are further reinforced by an examination of pointless topology and Stone duality. A few of the more prominent categories of domains are surveyed, and Stone-type dualities for the objects of some of these categories are presented. The above dualities are then applied to the task of presenting domains as logical theories. Two types of logical theory are considered, namely axiomatic systems, and Gentzen-style deductive systems. The way in which these theories describe domains is by capturing the relationships between the open subsets of domains

Placing humans and non-humans in a trinitarian and geographical dynamic: Colin Gunton and Bruno Latour on nature, society, and modernity

This thesis is centrally concerned to provide a detailed theological and interdisciplinary account of how the dynamic relationality between humans and nonhumans may be registered and accounted for in a Trinitarian and geographical framework. The method of this study is to establish a mutually critical and enlightening conversation between the fields of Trinitarian theology, science studies, and human geography. The thesis then takes as its primary interlocutors Trinitarian theologian Colin E. Gunton, and science studies theoretician Bruno Latour. A detailed discussion of each author's respective diagnoses of the Enlightenment's cultural, philosophical and theological fallout is offered. The study lends particular focus to the way in which each interlocutor has detailed the modern movement to fragment or distance the realms of God, humans, and nonhumans. Further in this vein, the study then moves to consider a critical comparison of each author's respective positive programs - 'Trinitarianism' and 'nonmodernism' respectively - for navigating our way out ofthe many pitfalls of modern thought.The study concludes with an attempt to bring the insights of Gunton's Trinitarian thought and Latour's 'nonmodern' project into conversation with the human geographical concept of place/placing. Here it is argued that a theological adoption of the geographical concept of place/placing would allow for a more detailed account of nonhuman participation in sociality, nonhuman agency/actancy, and nonhuman participation in human personhood. The culmination ofthese efforts is to be found in the construction of a specifically Trinitarian theo-geographical concept of place/placing that would allow for a theology capable of more fully registering the dynamic relationality that exists between persons and things, humans and nonhumans, culture and nature. By engaging Trinitarian theology in a mutually critical conversation with the fields of science studies and human geography, it is argued that we are better able to construct a distinctly theological means of registering the deep relationality that exists between humans and the multiplicity of nonhumans with whom we share a common world

The Common Order-Theoretic Structure of Version Spaces and ATMS\u27s

This paper exposes the common order-theoretic properties of the structures manipulated by the version space algorithm [Mit78]and the assumption-based truth maintenance systems (ATMS) [dk86a,dk86b] by recasting them in the framework of convex spaces. Our analysis of version spaces in this framework reveals necessary and sufficient conditions for ensuring the preservation of an essential finite representability property in version space merging. This analysis is used to formulate several sufficient conditions for when a language will allow version spaces to be represented by finite sets of concepts (even when the universe of concepts may be infinite). We provide a new convex space based formulation of computation performs by an ATMS which extends the expressiveness of disjunctions in the systems. This approach obviates the need for hyper-resolution in dealing with disjunction and results in simpler label-update algorithms

Analysing the familiar : reasoning about space and time in the everyday world

The development of suitable explicit representations of knowledge that can be manipulated by general purpose inference mechanisms has always been central to Artificial Intelligence (AI). However, there has been a distinct lack of rigorous formalisms in the literature that can be used to model domain knowledge associated with the everyday physical world. If AI is to succeed in building automata that can function reasonably well in unstructured physical domains, the development and utility of such formalisms must be secured. This thesis describes a first order axiomatic theory that can be used to encode much topological and metrical information that arises in our everyday dealings with the physical world. The formalism is notable for the minimal assumptions required in order to lift up a very general framework that can cover the representation of much intuitive spatial and temporal knowledge. The basic ontology assumes regions that can be either spatial or temporal and over which a set of relations and functions are defined. The resulting partitioning of these abstract spaces, allow complex relationships between objects and the description of processes to be formally represented. This also provides a useful foundation to control the proliferation of inference commonly associated with mechanised logics. Empirical information extracted from the domain is added and mapped to these basic structures showing how further control of inference can be secured. The representational power of the formalism and computational tractability of the general methodology proposed is substantiated using two non-trivial domain problems - modelling phagocytosis and exocytosis of uni-cellular organisms, and modelling processes arising during the cycle of operations of a force pump

Research summary, January 1989 - June 1990

The Research Institute for Advanced Computer Science (RIACS) was established at NASA ARC in June of 1983. RIACS is privately operated by the Universities Space Research Association (USRA), a consortium of 62 universities with graduate programs in the aerospace sciences, under a Cooperative Agreement with NASA. RIACS serves as the representative of the USRA universities at ARC. This document reports our activities and accomplishments for the period 1 Jan. 1989 - 30 Jun. 1990. The following topics are covered: learning systems, networked systems, and parallel systems

Arresting vision : a geographical theory of Antarctic light

As a site at the margin of terrestrial systems, Antarctica disrupts the usual practices of visual representation. This thesis investigates, what I call, chronogeographical approaches to visual culture within the Antarctic terrain. The material and theoretical chronogeographies of vision are mapped through the action of light, to elucidate on the shifting terrain of form - that is the Antarctic landscape. Historically, the thesis explores how the 1980s anti-mining campaign, organised by environmental groups challenged the political and visual hegemony of the Antarctic Treaty Consultative Parties. The campaign highlighted the feedback between the circulation of images and initiatives to protect the Antarctic landscape. Situated within this visual economy, the thesis focuses on how representation demarcates abstract and imaginative spaces for the production of the landscape - creating fugitive images of Antarctic spatialities. The thesis follows the fugitive testimony of the image through fields of knowledge, from the arrest and flow of landscape to the aesthetics of mobility. Critical art practice is considered as an interstice that highlights the conditions under which landscapes are given visibility, both cognitively and optically. A stratum of histories, mappings and sitings, structure the investigation into the transmission, materiality, and memory embedded in different media employed in the production of Antarctica. Through this sedimentation of geographies, the thesis proposes that the limits of representation may be found in Antarctica. It is argued that this shattering of commonly available visual languages can be a means to aerate our creative explorations of place. From this site, broader issues about the economy of the visual and the limits of visibility are examined. The thesis concludes that only by attending to the complex geographies of the image can the geopolitical aesthetics of place be accounted for.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Networks of Nature: Stories of Natural History Film-making at the BBC

In May 1953 the first natural history television programme was broadcast from Bristol by naturalist Peter Scott and radio producer Desmond Hawkins. By 1997 the BBC's Natural History Unit has established a global reputation for wildlife films, providing a keystone of the BBC's public service broadcasting charter, playing an important strategic role in television scheduling and occupying a prominent position in a competitive world film market. The BBC's blue-chip natural history programmes regularly bring images of wildlife from all over the globe to British audiences of over 10 million. This thesis traces the changing aesthetics, ethics and economics of natural history film-making at the BBC over this period. It uses archive material, interviews and participant observation to look at how shifting relationships between broadcasting values, scientific and film-making practices are negotiated by individuals within the Unit. Engaging with vocabularies from geography, media studies and science studies, the research contextualises these popular representations of nature within a history of post-war British attitudes to nature and explores the importance of technology, animals and conceptions of the public sphere as additional actors influencing the relationships between nature and culture. This history charts the construction of the actor networks of the Natural History Unit by film-makers and broadcasters as they seek to incorporate and exclude certain practices, technologies and discourses of nature. These networks provide the resources, values and constraints which members of the Unit negotiate to seek representation within the Unit, and present challenges as the Unit seeks to preserve its institutional identity as these networks shift. The thesis tells a series of stories of natural history film-making that reflect one institution's contributions and responses to the contemporary formations of nature, science, the media and modernity