Internalising modified realisability in constructive type theory

A modified realisability interpretation of infinitary logic is formalised and proved sound in constructive type theory (CTT). The logic considered subsumes first order logic. The interpretation makes it possible to extract programs with simplified types and to incorporate and reason about them in CTT.Comment: 7 page

Model and Proof Theory of Constructive ALC, Constructive Description Logics

Description logics (DLs) represent a widely studied logical formalism with a significant impact in the field of knowledge representation and the Semantic Web. However, they are equipped with a classical descriptive semantics that is characterised by a platonic notion of truth, being insufficiently expressive to deal with evolving and incomplete information, as from data streams or ongoing processes. Such partially determined and incomplete knowledge can be expressed by relying on a constructive semantics. This thesis investigates the model and proof theory of a constructive variant of the basic description logic ALC, called cALC. The semantic dimension of constructive DLs is investigated by replacing the classical binary truth interpretation of ALC with a constructive notion of truth. This semantic characterisation is crucial to represent applications with partial information adequately, and to achieve both consistency under abstraction as well as robustness under refinement, and on the other hand is compatible with the Curry-Howard isomorphism in order to form the cornerstone for a DL-based type theory. The proof theory of cALC is investigated by giving a sound and complete Hilbert-style axiomatisation, a Gentzen-style sequent calculus and a labelled tableau calculus showing finite model property and decidability. Moreover, cALC can be strengthened towards normal intuitionistic modal logics and classical ALC in terms of sound and complete extensions and hereby forms a starting point for the systematic investigation of a constructive correspondence theory.Beschreibungslogiken (BLen) stellen einen vieluntersuchten logischen Formalismus dar, der den Bereich der Wissensrepräsentation und das Semantic Web signifikant geprägt hat. Allerdings basieren BLen meist auf einer klassischen deskriptiven Semantik, die gekennzeichnet ist durch einen idealisierten Wahrheitsbegriff nach Platons Ideenlehre, weshalb diese unzureichend ausdrucksstark sind, um in Entwicklung befindliches und unvollständiges Wissen zu repräsentieren, wie es beispielsweise durch Datenströme oder fortlaufende Prozesse generiert wird. Derartiges partiell festgelegtes und unvollständiges Wissen lässt sich auf der Basis einer konstruktiven Semantik ausdrücken. Diese Arbeit untersucht die Model- und Beweistheorie einer konstruktiven Variante der Basis-BL ALC, die im Folgenden als cALC bezeichnet wird. Die Semantik dieser konstruktiven Beschreibungslogik resultiert daraus, die traditionelle zweiwertige Interpretation logischer Aussagen des Systems ALC durch einen konstruktiven Wahrheitsbegriff zu ersetzen. Eine derartige Interpretation ist die Voraussetzung dafür, um einerseits Anwendungen mit partiellem Wissen angemessen zu repräsentieren, und sowohl die Konsistenz logischer Aussagen unter Abstraktion als auch ihre Robustheit unter Verfeinerung zu gewährleisten, und andererseits um den Grundstein für eine Beschreibungslogik-basierte Typentheorie gemäß dem Curry-Howard Isomorphismus zu legen. Die Ergebnisse der Untersuchung der Beweistheorie von cALC umfassen eine vollständige und korrekte Hilbert Axiomatisierung, einen Gentzen Sequenzenkalkül, und ein semantisches Tableaukalkül, sowie Beweise zur endlichen Modelleigenschaft und Entscheidbarkeit. Darüber hinaus kann cALC zu normaler intuitionistischer Modallogik und klassischem ALC durch vollständige und korrekte Erweiterungen ausgebaut werden, und bildet damit einen Startpunkt für die systematische Untersuchung einer konstruktiven Korrespondenztheorie

Agency and Organisation: The Dialectics of Nature and Life

In recent decades, there have been major theoretical changes within evolutionary biology. In this dissertation, I critically reconstruct these developments through philosophy to assess how it may inform these debates. The overall aim is to show the mutual relevance between current trends in biology and the dialectical approach to nature. I argue that the repetition of the neglected tradition of organicism is anticipated both by a dialectical tradition within science and by Hegel’s philosophy – and that these theories may together inform the ongoing shift within evolutionary biology called the Extended Evolutionary Synthesis (EES). I stage the discussion by outlining the tenets and history of the modern synthesis (MS) and the alternative: the extended evolutionary synthesis (EES). It takes us into topics such as autonomy, organisation, reduction, and autopoiesis. Based on these discussions, I make the case that the most promising alternative to the MS is the so-called organisational approach formulated within theoretical biology and apply dialectics to strengthen this claim. In my view, they share a fundamental premise: Biology must surpass the physical worldview and adopt a more complex model to comprehend life as an ongoing regeneration of organisation and an expression of self-determination. To bring out the philosophical stakes of this shift, I take on Hegel’s writings on nature, life, and purposiveness and relate them to contemporary thinkers. The main contribution of this work lies not in a particularly novel reading of any of the theories I examine but in bringing them together – both within philosophy and biology and between them – and systematically mapping how philosophy and the humanities should deal with the natural sciences. The new kind of naturalism suggested here, which places life at its core, also calls for another scientific ideal which strives for unification without subsumption or eradication of differences

Managing social risk through stakeholder partnership building : empirical descriptive process analysis of stakeholder partnerships from British Petroleum in Colombia and Hoechst in Germany for the management of social risk

This thesis sets out to provide a systematic study of stakeholder partnership building of BP in Colombia and Hoechst in Germany in the context of social risk management. Each company built an NGO and a community partnership that became an integral part of firms' strategy. In examining and evaluating the two companies and the four stakeholder partnerships, the leading research question of how firms build stakeholder partnerships is answered. The present study seeks to identify the characteristics of stakeholder partnership building, as well as to isolate the similarities and differences of this process. Additionally, it is an attempt to define the features of the firms' social risk navigation as context of this research project. The thesis is divided into four parts. The first part introduces the research phenomenon, reviews conceptual foundations, and elaborates methodological issues. The case studies of BP and Hoechst are subdivided into internal processes of social integration and reintegration with regard to the two companies, and external processes of partnership building with regard to the four stakeholder partnerships that are chronologically presented in part two. Part three conceptualises stakeholder partnership building in terms of navigating social risk and partnership alchemy. Finally, part four comprises the research synopsis and reflection. Business and society, stakeholder theory, and strategic relationships are the theoretical areas that contributed to the framework for analysing partnership building. Two longitudinal in-depth case studies provide qualitative data for the processual analysis. The empirical data are categorised, aggregated and compared, in order to extract research findings. The contribution of this research is the extension of behavioural stakeholder theory. It develops is a stakeholder partnership building theory that comprises three parts. First, the 4-Ps of stakeholder partnership building are identified. Second, variables are isolated that describe these elements of partnership alchemy. Finally, four patterns of stakeholder partnership building are identified. As a result, the research presents four propositions for partnership building. Based on the analysis of firms' navigation of social risk, a fifth proposition distinguishes between firm-specific and partnership-specific partnership building. The empirical data provides a contribution to knowledge in its own right by providing detailed insight into the practice of social risk management through stakeholder partnership building

Buffering preconscious stressor appraisal: the protective role of self-efficacy

This thesis was submitted for the degree of Doctor of Education and awarded by Brunel University.Many cognitive resources contribute towards the appraisal of stressors. Of these, self-efficacy (SE) is widely acknowledged to play a significant role in protecting adolescents from the effects of stress (Bandura, 1997). This study investigated that relationship through the use of a quasi-experimental methodology (Cook & Campbell, 1979) utilising an untreated Control group of 44 adolescent, female participants and an Experimental group of 70 additional participants, all of whom were volunteers drawn from the Sixth Form of a single participating school. The members of both participant groups took part in two rounds of testing, between which the members of the Experimental group were exposed to a significant academic stressor (one or more public A-level examinations). During both test phases, all participants completed the 10- item Perceived Stress Scale self-report (Cohen & Williamson, 1988), the Examination Self-Efficacy Scale instrument (Schwarzer & Jerusalem, 1995) and a bespoke Implicit Association Test (Greenwald et al., 1998) designed to measure implicit stressor appraisal. Significant trends were identified by means of ANCOVA, correlation and regression analyses, and the resulting data were interpreted in terms of a dual process model of stress (Compas, 2004). Results not only concurred with those of previous studies (e.g. Betoret, 2006; Vaezi & Fallah, 2011) by demonstrating a strongly negative correlation between acute academic stress and academic SE, but provided new evidence to suggest that the ‘protective’ effect of SE occurs via a buffering mechanism at the level of preconscious stressor appraisals (Bargh, 1990), which limits the effect of acute stress exposure on preconscious stressor appraisals (e.g. Luecken & Appelhans, 2005)

Where is cognition? Towards an embodied, situated, and distributed interactionist theory of cognitive activity

In recent years researchers from a variety of cognitive science disciplines have begun to challenge some of the core assumptions of the dominant theoretical framework of cognitivism including the representation-computational view of cognition, the sense-model-plan-act understanding of cognitive architecture, and the use of a formal task description strategy for investigating the organisation of internal mental processes. Challenges to these assumptions are illustrated using empirical findings and theoretical arguments from the fields such as situated robotics, dynamical systems approaches to cognition, situated action and distributed cognition research, and sociohistorical studies of cognitive development. Several shared themes are extracted from the findings in these research programmes including: a focus on agent-environment systems as the primary unit of analysis; an attention to agent-environment interaction dynamics; a vision of the cognizer's internal mechanisms as essentially reactive and decentralised in nature; and a tendency for mutual definitions of agent, environment, and activity. It is argued that, taken together, these themes signal the emergence of a new approach to cognition called embodied, situated, and distributed interactionism. This interactionist alternative has many resonances with the dynamical systems approach to cognition. However, this approach does not provide a theory of the implementing substrate sufficient for an interactionist theoretical framework. It is suggested that such a theory can be found in a view of animals as autonomous systems coupled with a portrayal of the nervous system as a regulatory, coordinative, and integrative bodily subsystem. Although a number of recent simulations show connectionism's promise as a computational technique in simulating the role of the nervous system from an interactionist perspective, this embodied connectionist framework does not lend itself to understanding the advanced 'representation hungry' cognition we witness in much human behaviour. It is argued that this problem can be solved by understanding advanced cognition as the re-use of basic perception-action skills and structures that this feat is enabled by a general education within a social symbol-using environment

Internalising modified realisability in constructive type theory

A modified realisability interpretation of infinitary logic is formalised and proved sound in constructive type theory (CTT). The logic considered subsumes first order logic. The interpretation makes it possible to extract programs with simplified types and to incorporate and reason about them in CTT

Proceedings of the 3rd International Workshop on Formal Aspects in Security and Trust (FAST2005)

The present report contains the pre-proceedings of the third international Workshop on Formal Aspects in Security and Trust (FAST2005), held in Newcastle upon Tyne, 18-19 July 2005. FAST is an event affliated with the Formal Methods 2005 Congress (FM05). The third international Workshop on Formal Aspects in Security and Trust (FAST2005) aims at continuing the successful effort of the previous two FAST workshop editions for fostering the cooperation among researchers in the areas of security and trust. The new challenges offered by the so-called ambient intelligence space, as a future paradigm in the information society, demand for a coherent and rigorous framework of concepts, tools and methodologies to provide user\u27s trust&confidence on the underlying communication/interaction infrastructure. It is necessary to address issues relating to both guaranteeing security of the infrastructure and the perception of the infrastructure being secure. In addition, user confidence on what is happening must be enhanced by developing trust models effective but also easily comprehensible and manageable by users

Utilitarianism and the Social Nature of Persons

This thesis defends utilitarianism: the view that as far as morality goes, one ought to choose the option which will result in the most overall well-being. Utilitarianism is widely rejected by philosophers today, largely because of a number of influential objections. In this thesis I deal with three of them. Each is found in Bernard Williams’s ‘A Critique of Utilitarianism’ (1973). The first is the Integrity Objection, an intervention that has been influential whilst being subject to a wide variety of interpretations. In Chapter Two I give my interpretation of Williams’s Integrity objection; in Chapter Three I discuss one common response to it, and in Chapters Four and Five I give my own defence of utilitarianism against it. In Chapter Six I discuss a second objection: the problem of pre-emption. This problem is also found in Williams, but has received greater attention through the work of other authors in recent years. It suggests that utilitarianism is unable to deal with some of the modern world’s most pressing moral problems, and raises an internal tension between the twin utilitarian aims of making a difference and achieving the best outcomes. In Chapter Seven I discuss a third objection: that utilitarianism is insufficiently egalitarian. I find this claim to be unwarranted, in light of recent social science and philosophy. My responses to Williams’s objections draw upon resources from the socialist tradition – in particular, that tradition’s emphasis on the importance of social connections between individuals. Socialists have often been hostile to utilitarianism, in part for socialist-inflected versions of Williams’s objections. Thus, in responding to these objections I aim to demonstrate that socialist thought contains the means to defuse not only mainstream philosophy’s rejection of utilitarianism but also its own, and thus to re-open the possibilities for a productive engagement between the two traditions