78 research outputs found

    Erasure in dependently typed programming

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    It is important to reduce the cost of correctness in programming. Dependent types and related techniques, such as type-driven programming, oļ¬€er ways to do so. Some parts of dependently typed programs constitute evidence of their typecorrectness and, once checked, are unnecessary for execution. These parts can easily become asymptotically larger than the remaining runtime-useful computation, which can cause linear-time algorithms run in exponential time, or worse. It would be unnacceptable, and contradict our goal of reducing the cost of correctness, to make programs run slower by only describing them more precisely. Current systems cannot erase such computation satisfactorily. By modelling erasure indirectly through type universes or irrelevance, they impose the limitations of these means to erasure. Some useless computation then cannot be erased and idiomatic programs remain asymptotically sub-optimal. This dissertation explains why we need erasure, that it is diļ¬€erent from other concepts like irrelevance, and proposes two ways of erasing non-computational data. One is an untyped ļ¬‚ow-based useless variable elimination, adapted for dependently typed languages, currently implemented in the Idris 1 compiler. The other is the main contribution of the dissertation: a dependently typed core calculus with erasure annotations, full dependent pattern matching, and an algorithm that infers erasure annotations from unannotated (or partially annotated) programs. I show that erasure in well-typed programs is sound in that it commutes with single-step reduction. Assuming the Church-Rosser property of reduction, I show that properties such as Subject Reduction hold, which extends the soundness result to multi-step reduction. I also show that the presented erasure inference is sound and complete with respect to the typing rules; that this approach can be extended with various forms of erasure polymorphism; that it works well with monadic I/O and foreign functions; and that it is eļ¬€ective in that it not only removes the runtime overhead caused by dependent typing in the presented examples, but can also shorten compilation times."This work was supported by the University of St Andrews (School of Computer Science)." -- Acknowledgement

    The Administrative Turn in Contemporary Art: The Figure of the Arts Administrator ā€” a case study of the Taipei Biennial (1996-2020)

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    This PhD uses ā€œthe Administrative Turnā€ to describe the specific, but also the more general, changing nature of the local and global administrative networks which support contemporary art. Through a case study of the figure of the arts administrator at the Taipei Biennial (TB), this research examines these changes in three ways ā€“ on (1) changes in institutional principles of arts administration, (2) changes in administrative methodology, and (3) changes in function for arts administrators. Taking a transdisciplinary approach drawing on Arts Management, Curatorial Studies, Museum Studies and Art History, this thesis engages critically with the value of ā€œthe administrativeā€ as a necessary approach to catalyse a shift in focus away from the highly visible and spectacularised norm of the global contemporary art world, towards the infrastructural significance of the backstage. This change in perspective through the study of the TB arts administrators sets out to present a missing puzzle of what makes that art world functions as it does and how in fact the support network of the contemporary art practices have transformed because of changes in the administrative capacity in terms of its institution, methodology and function. Chapter 1 details the developmental history of the system of arts administration at TB, as an institution situated within a government-backed, museum-based, contemporary art exhibitionary ecosystem, and finds that the institution history and design principles of arts administration are not only a reflection but also an active author of Taiwanese national identity. Chapter 2 demonstrates how arts management and its methodology as a practice-centric tradecraft based on the narrative of professionalism and a stewardship process, is iterative and relies on a balance of control and care. With a close analysis of the administrative capacity, Chapter 3 establishes the figure of the arts administrators as reflexive and its function pedagogical and consultative. This research concludes that acting as critical infrastructure, arts administrators as ascending co-development stewards, possess the transformative agency to radically re-imagine their sphere of practice and re-conceptualise how the support network could better function for a fast-evolving and increasingly multi-stakeholder production reality, which underpins the culture of contemporary art biennials globally

    Business sustainability: understanding the influence of managers and stakeholders on adopting sustainability practices in Nigerian SMEs

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    A thesis submitted in partial fulfilment of the requirements of the University of Wolverhampton for the Degree of Doctor of Philosophy.The importance of small and medium enterprises (SMEs) in any economy must be balanced, yet hardly the sector attracts the needed attention for sustainability. This has led to unacceptable high mortality rates for the sector, especially in emerging contexts. Nevertheless, SMEs and sustainability agenda share significant melting pots of disrupting large-scale extreme poverty, among other benefits. Numerous literature supports this and acknowledges SMEs' potential for national employment, investment stimulation and gross domestic growth (GDP). This study aimed to unveil the impacts of managerial characteristics and stakeholders on Nigerian SME sustainability practices to understand SME business sustainability practices in developing countries. To fully investigate these impacts, three research questions enabled the navigation of this project. Firstly, to ascertain the current antecedents influencing SME sustainability practices. Secondly, we quizzed the relationship between the manager's characteristics and Nigerian SME sustainability practices. Furthermore, finally, we sort out how stakeholders influence SMEs' sustainability practices in Nigeria. A qualitative research approach was adopted within an interpretivist philosophical paradigm to construct participants narrated perspectives of sustainability practices. Data were collected from twenty-two (22) Nigerian SME owners/managers and nine (9) stakeholders in semi-structured interviews, virtually. Participants' information was inductively condensed, analysed and thematically framed using the Upper Echelon and Stakeholder concepts. The findings were dimensionally extracted using Gioia's step/order analysis to develop a data structure for each research question. The findings for the current antecedence include the political and governance dimension, the cultural and societal dimension, the economic dimension, and the business orientation dimension. In contrast, the findings for the relationship between managerial characteristics and sustainability practices include observable dimensions and cognitive values. The finding for stakeholder influence on sustainability practices includes the managerial alignment dimension and the dimension of stakeholdersā€™ intervention. Asides from the contribution to knowledge, the result presented national, organisational and managerial practical implications. Diverse organisational and regulatory policy implications were also presented with future research directions

    Where Regulation Ends: Enforceable Undertakings, the Australian Securities and Investments Commission and the Perils of Unresponsiveness

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    The Australian Securities and Investments Commission has staked its legitimacy and effectiveness on a commitment to responsive regulation. Arguably the most influential theory in the field since James Landis provided an initial justification for the regulatory state in The Administrative Process (1938), Ian Ayres and John Braithwaiteā€™s account in Responsive Regulation (1992) privileges negotiation over coercion to exert social control over corporate behaviour, the subject of Christopher Stoneā€™s magisterial account of Where the Law Ends (1975). How ASIC deployed the enforcement pyramid models at the core of responsive regulation, however, raises profound practical questions and theoretical issues. From a practical perspective, this thesis demonstrates tactical failure. At the theoretical level, ASICā€™s blindness to the normative dimensions of responsive regulation highlights the danger of cherry-picking, for the regulator and the academy alike. The thesis evaluates ASICā€™s enforcement strategy, most notably its preference for negotiated settlements over judicially determined deterrence strategies in the form of Enforceable Undertakings. Combining quantitative analysis of overarching enforcement strategies and qualitative case studies, the thesis casts doubt on the value of responsive regulation and the enforcement pyramids it mandates when critical embedded normative considerations are ignored or downplayed. In emphasising the importance of defining purpose at corporate, regulatory, judicial and legislative levels, the thesis offers ways to rescue responsive regulation from an intellectual and practical dead end

    On the readability of machine checkable formal proofs

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    It is possible to implement mathematical proofs in a machine-readable language. Indeed, certain proofs, especially those deriving properties of safety-critical systems, are often required to be checked by machine in order to avoid human errors. However, machine checkable proofs are very hard to follow by a human reader. Because of their unreadability, such proofs are hard to implement, and more difficult still to maintain and modify. In this thesis we study the possibility of implementing machine checkable proofs in a more readable format. We design a declarative proof language, SPL, which is based on the Mizar language. We also implement a proof checker for SPL which derives theorems in the HOL system from SPL proof scripts. The language and its proof checker are extensible, in the sense that the user can modify and extend the syntax of the language and the deductive power of the proof checker during the mechanisation of a theory. A deductive database of trivial knowledge is used by the proof checker to derive facts which are considered trivial by the developer of mechanised theories so that the proofs of such facts can be omitted. We also introduce the notion of structured straightforward justifications, in which simple facts, or conclusions, are justified by a number of premises together with a number of inferences which are used in deriving the conclusion from the given premises. A tableau prover for first-order logic with equality is implemented as a HOL derived rule and used during the proof checking of SPL scripts. The work presented in this thesis also includes a case study involving the mechanisation of a number of results in group theory in SPL, in which the deductive power of the SPL proof checker is extended throughout the development of the theory

    Programming Languages and Systems

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    This open access book constitutes the proceedings of the 31st European Symposium on Programming, ESOP 2022, which was held during April 5-7, 2022, in Munich, Germany, as part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2022. The 21 regular papers presented in this volume were carefully reviewed and selected from 64 submissions. They deal with fundamental issues in the specification, design, analysis, and implementation of programming languages and systems

    Proceedings of the Seventh Italian Conference on Computational Linguistics CLiC-it 2020

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    On behalf of the Program Committee, a very warm welcome to the Seventh Italian Conference on Computational Linguistics (CLiC-it 2020). This edition of the conference is held in Bologna and organised by the University of Bologna. The CLiC-it conference series is an initiative of the Italian Association for Computational Linguistics (AILC) which, after six years of activity, has clearly established itself as the premier national forum for research and development in the fields of Computational Linguistics and Natural Language Processing, where leading researchers and practitioners from academia and industry meet to share their research results, experiences, and challenges

    Constitutive surveillance and social media

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    Starting from the premise that surveillance is the ā€˜dominant organising practiceā€™ of our time (Lyon et al 2012: 1), this thesis establishes a framework of ā€˜constitutive surveillanceā€™ in relation to social media, taking Facebook as its key example. Constitutive surveillance is made up of four forms: economic, political, lateral, and oppositional surveillance. These four surveillance forms ā€“ and the actors who undertake them ā€“ intersect, compound, and confront one another in the co-production of social media spaces. The framework of constitutive surveillance is structured around a Foucauldian understanding of power, and the thesis shows how each surveillance form articulates strategies of power for organising, administering, and subjectifying populations. After outlining the four surveillance forms, each chapter unpacks the relationship of one form to social media, building throughout the thesis an extensive critical framework of constitutive surveillance

    Coping with political corporatism: state-international non-governmental organisation relations in post-2000 Zimbabwe.

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    Doctoral Degree. University of KwaZulu-Natal, Durban.This thesis focuses on the relations between International Non-governmental Organisations (INGOs) and the State in post-2000 Zimbabwe (2000ā€“2009). This was an epoch depicting the democratisation process as posing a threat to the reign of Robert Gabriel Mugabe since 1980. My thesis is that in post-2000 Zimbabwe, INGOs and the State co-existed in a dichotomy where they needed each other. The aim of the study is to describe the nature of INGO-State relations in post-2000 Zimbabwe and construct an explanatory theoretical framework. The study is guided by the main research question: How have INGOs coped with political corporatism in the post-2000 Zimbabwe period? The study focuses on the nature of political repression directed at the INGOs by the post-2000 Zimbabwe and how the INGOs coped with the hostile political environment in fulfilling their mandate. The setting of the study is post-2000, a time when Zimbabwe was characterised by a severe economic meltdown, political contestation and political violence. The study employs two theoretical frameworks, namely Michael Foucaultā€™s theory of governmentality and Pierre Bourdieuā€™s theory of the State. The study is philosophically grounded in the interpretivist paradigm and adopts a case study design and a qualitative research approach. Purposeful and snowballing sampling techniques were used complementarily to access willing participants. The sample consisted of 21 informants from INGO officials and State officials. From the INGOs, five participants were engaged in humanitarian organisations while five were engaged in developmental INGOs. Eleven participants were evenly spread among five government departments. The semi-structured interview was used as the major instrument of data collection augmented by document analysis of the Private Voluntary Organisationsā€™ Act (2002) and the NGO Bill (2004) and other statutory instruments regulating the operations of INGOs in post-2000 Zimbabwe. The study finds that from 2000 onwards, the State in Zimbabwe used its governmentalities and capital to effect political corporatism or repression against INGOs. The co-existence of INGOs and the State was characterised by antagonism and mistrust although they concomitantly needed each other. Political corporatism became the instrument for controlling INGOs, political ideology and political dissent. Confronted with dilemmas, INGOs had to adopt coping strategies in post-2000 Zimbabwe. The study advances the theory of expedience in explaining the nature of INGOā€“State relations in post-2000 Zimbabwe as its major contribution to knowledge on INGOā€“State relations. The theory of expedience posits that both parties to a conflict need each other on one hand and are in bitter rivalry on the other hand. The pendulum of power swings between political power and the power of resources. The study recommends the removal of hindrances to enhance the smooth operations of INGOs such as limiting the powers of the executive directors and ministers as enshrined in the NGO Bill (2004) and PVO Act (2002), repealing repressive laws, and freeing the airwaves and the media as a way of fostering the democratic participation of organisations and citizens. Democratic participation helps to cultivate mutual trust and confidence. The respect for human rights and rule of law cannot be over-emphasised
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