Hybrid programs

The MAP-i Doctoral Programme in Informatics, of the Universities of Minho, Aveiro and PortoThis thesis studies hybrid systems, an emerging family of devices that combine in their models digital computations and physical processes. They are very quickly becoming a main concern in software engineering, which is explained by the need to develop software products that closely interact with physical attributes of their environment e. g. velocity, time, energy, temperature – typical examples range from micro-sensors and pacemakers, to autonomous vehicles, transport infrastructures and district-wide electric grids. But even if already widespread, these systems entail different combinations of programs with physical processes, and this renders their development a challenging task, still largely unmet by the current programming practices. Our goal is to address this challenge at its core; we wish to isolate the basic interactions between discrete computations and physical processes, and bring forth the programming paradigm that naturally underlies them. In order to do so in a precise and clean way, we resort to monad theory, a well established categorical framework for developing program semantics systematically. We prove the existence of a monad that naturally encodes the aforementioned interactions, and use it to develop and examine the foundations of the paradigm alluded above, which we call hybrid programming: we show how to build, in a methodical way, different programming languages that accommodate amplifiers, differential equations, and discrete assignments – the basic ingredients of hybrid systems – we list all program operations available in the paradigm, introduce if-then-else constructs, abort operations, and different types of feedback. Hybrid systems bring several important aspects of control theory into computer science. One of them is the notion of stability, which refers to a system’s capacity of avoiding significant changes in its output if small variations in its state or input occur. We introduce a notion of stability to hybrid programming, explore it, and show how to analyse hybrid programs with respect to it in a compositional manner. We also introduce hybrid programs with internal memory and show that they form the basis of a component-based software development discipline in hybrid programming. We develop their coalgebraic theory, namely languages, notions of behaviour, and bisimulation. In the process, we introduce new theoretical results on Coalgebra, including improvements of well-known results and proofs on the existence of suitable notions of behaviour for non-deterministic transition systems with infinite state spaces.Esta tese estuda sistemas híbridos, uma família emergente de dispositivos que envolvem diferentes interações entre computações digitais e processos físicos. Estes sistemas estão rapidamente a tornar-se elementos-chave da engenharia de software, o que é explicado pela necessidade de desenvolver produtos que interagem com os atributos físicos do seu ambiente e. g. velocidade, tempo, energia, e temperatura – exemplos típicos variam de micro-sensores e pacemakers, a veículos autónomos, infra-estruturas de transporte, e redes eléctricas distritais. Mas ainda que amplamente usados, estes sistemas são geralmente desenvolvidos de forma pouco sistemática nas prácticas de programação atuais. O objetivo deste trabalho é isolar as interações básicas entre computações digitais e processos físicos, e subsequentemente desenvolver o paradigma de programação subjacente. Para fazer isto de forma precisa, a nossa base de trabalho irá ser a teoria das mónadas, uma estrutura categórica para o desenvolvimento sistemático de semânticas na programação. A partir desta base, provamos a existência de uma mónada que capta as interações acima mencionadas, e usamo-la para desenvolver e examinar os fundamentos do paradigma de programação correspondente a que chamamos programação híbrida: mostramos como construir, de maneira metódica, diferentes linguagens de programação que acomodam amplificadores, equações diferenciais, e atribuições - os ingredientes básicos dos sistemas híbridos - caracterizamos todas as operações sobre programas disponíveis, introduzimos construções if-then-else, operações para lidar com excepções, e diferentes tipos de feedback. Os sistemas híbridos trazem vários aspectos da teoria de controlo para a ciência da computação. Um destes é a noção de estabilidade, que se refere à capacidade de um sistema de evitar mudanças drásticas no seu output se pequenas variações no seu estado ou input ocorrerem. Neste trabalho, desenvolvemos uma noção composicional de estabilidade para a programação híbrida. Introduzimos também programas híbridos com memória interna, que formam a base de uma disciplina de desenvolvimento de software baseado em componentes. Desenvolvemos a sua teoria coalgébrica, nomeadamente linguagens, noções de comportamento e bisimulação. Neste processo, introduzimos também novos resultados teóricos sobre Coalgebra, incluindo melhorias a resultados conhecidos e provas acerca da existência de noções de comportamento para sistemas de transição não determinísiticos com espaço de estados infinitos.The present work was financed by FCT – Fundação para a Ciência e a Tecnologia – with the grant SFRH/BD/52234/2013. Additional support was provided by the PTFLAD Chair on Smart Cities & Smart Governance and by project Dalí (POCI-01-0145-FEDER-016692), the latter funder by ERDF – European Regional Development Fund – through COMPETE 2020 – Operational Programme for Competitiveness and Internationalisation – together with FCT

Against the Virtual: Kleinherenbrink’s Externality Thesis and Deleuze’s Machine Ontology

Drawing from Arjen Kleinherenbrink's recent book, Against Continuity: Gilles Deleuze's Speculative Realism (2019), this paper undertakes a detailed review of Kleinherenbrink's fourfold "externality thesis" vis-à-vis Deleuze's machine ontology. Reading Deleuze as a philosopher of the actual, this paper renders Deleuzean syntheses as passive contemplations, pulling other (passive) entities into an (active) experience and designating relations as expressed through contraction. In addition to reviewing Kleinherenbrink's book (which argues that the machine ontology is a guiding current that emerges in Deleuze's work after Difference and Repetition) alongside much of Deleuze's oeuvre, we relate and juxtapose Deleuze's machine ontology to positions concerning externality held by a host of speculative realists. Arguing that the machine ontology has its own account of interaction, change, and novelty, we ultimately set to prove that positing an ontological "cut" on behalf of the virtual realm is unwarranted because, unlike the realm of actualities, it is extraneous to the structure of becoming-that is, because it cannot be homogenous, any theory of change vis-à-vis the virtual makes it impossible to explain how and why qualitatively different actualities are produced

THE IMPOSITION OF THE EGO: JEAN-PAUL SARTRE AND THE CINEMATIC APPARATUS

This thesis applies Jean-Paul Sartre’s early philosophy of consciousness and ego to two main concepts of Jean-Louis Baudry’s theory of the cinematic apparatus. The first of these concepts, the “transcendental subject,” is denoted by Baudry as the conflation of Cartesian philosophy and technology which ensures the transmission of representational knowledge in line with a historically dominant optical ideology. Since Sartre criticizes the transcendental phenomenology of Husserl in ways similar to Baudry’s work, his structures and levels of consciousness apply well to the enforced cohesion of the transcendental subject, and impart a hitherto lacking cohesion to the concept. Following from a clear structuration of the transcendental subject, the thesis then moves to the “more-than-real,” or the impression of reality found in dream that is then objectively staged in the apparatus. For Baudry, dream enacts the desire to endure unconscious representation in the same manner as waking perception, this desire itself stemming from a wish to return to the pre-subjective wholeness of infancy. Cinema, then, enacts an “artificial regression,” or a simulation of the regression required for dream, in order to endure the more-than-real in waking reality. In order to explain the process of the more-than- real, the transcendental subject is then schematized in its interaction with the general projection situation and the spectator, from which is concluded that the transcendental subject engages with the spectator in order to produce for the spectator a position in which to experience “reality unfolding itself.” Finally, the implications for both materialist film, Althusserian ideology, and the notion of “apparatus” in general are briefly explored

Signposts to Silence. Metaphysical mysticism

Signposts to Silence provides a theoretical map of what it terms ‘metaphysical mysticism’: the search for the furthest, most inclusive horizon, the domain of silence, which underlies the religious and metaphysical urge of humankind in its finest forms. Tracing the footsteps of pioneers of this exploration, the investigation also documents a number of historical pilgrimages from a variety of cultural and religious backgrounds. Such mountaineers of the spirit, who created paths trodden by groups of followers over centuries and in some cases millennia, include Lao-Tzu and Chuang-Tzu, Siddhattha and Jesus, Sankara and Fa-tsang, Plato and Plotinus, Isaac Luria and Ibn Arabi, Aquinas and Hegel. Such figures, teachings and traditions (including the religions of ‘Judaism’, ‘Christianity’ and ‘Islam’; ‘Hinduism’, ‘Buddhism’ and ‘Taoism’) are understood as, at their most sublime, not final destiny and the end of the road, but signposts to a horizon of ultimate silence. The hermeneutical method employed in tracking such pioneers involves four steps: • sound historical-critical understanding of the context of the various traditions and figures • reconstruction of the subjective intentional structure of such persons and their teachings • design, by the author, of a theoretical map of the overall terrain of ‘metaphysical mysticism’, on which all such journeys of the spirit are to be located, while providing a theoretical context for understanding them tendentionally (i.e. taking the ultimate drift of their thinking essentially to transcend their subjective intentions) • drawing out, within the space available, some political (taken in a wide sense) implications from the above, such as religio-political stances as well as ecological and gender implications. Continuing the general direction of thought within what the author endorses to be the best in metaphysical mysticism in its historical manifestations, the book aims to contribute to peace amongst religions in the contemporary global cultural situation. It relativizes all claims to exclusive, absolute truth that might be proclaimed by any religious or metaphysical, mystical position, while providing space for not only tolerating, but also affirming the unique value and dignity of each. This orientation moves beyond the stances of enmity or indifference or syncretism or homogenisation of all, as well as that of mere friendly toleration. It investigates the seemingly daunting and inhospitable yet immensely significant Antarctica of the Spirit, the ‘meta’-space of silence behind the various forms of wordy ‘inter’-relationships. It affirms pars pro toto, totum pro parte, and pars pro parte: that each religious, mystical and metaphysical orientation in its relative singularity represents or contains the whole and derives value from that, and that each represents or contains every other. This homoversal solidarity stimulating individual uniqueness is different from and in fact implies criticism of the process of globalisation. While not taking part in a scientific argument as such, Signposts to Silence aims at promoting an understanding of science and metaphysical mysticism as mutual context for each other, and it listens to a number of voices from the domain of science that understand this

Large scale numerical software development using functional languages

PhD ThesisFunctional programming languages such as Haskell allow numerical algorithms to be expressed in a concise, machine-independent manner that closely reflects the underlying mathematical notation in which the algorithm is described. Unfortunately the price paid for this level of abstraction is usually a considerable increase in execution time and space usage. This thesis presents a three-part study of the use of modern purely-functional languages to develop numerical software. In Part I the appropriateness and usefulness of language features such as polymorphism. pattern matching, type-class overloading and non-strict semantics are discussed together with the limitations they impose. Quantitative statistics concerning the manner in which these features are used in practice are also presented. In Part II the information gathered from Part I is used to design and implement FSC. all experimental functional language tailored to numerical computing, motivated as much by pragmatic as theoretical issues. This language is then used to develop numerical software and its suitability assessed via benchmarking it against C/C++ and Haskell under various metrics. In Part III the work is summarised and assessed.EPSRC

Coinductive Equivalences and Metrics for Higher-order Languages with Algebraic Effects

This dissertation investigates notions of program equivalence and metric for higher-order sequential languages with algebraic effects. Computational effects are those aspects of computation that involve forms of interaction with the environment. Due to such an interactive behaviour, reasoning about effectful programs is well-known to be hard. This is especially true for higher-order effectful languages, where programs can be passed as input to, and returned as output by other programs, as well as perform side-effects. Additionally, when dealing with effectful languages, program equivalence is oftentimes too coarse, not allowing, for instance, to quantify the observable differences between programs. A natural way to overcome this problem is to re ne the notion of a program equivalence into the one of a program distance or program metric, this way allowing for a finer, quantitative analysis of program behaviour. A proper account of program distance, however, requires a more sophisticated theory than program equivalence, both conceptually and mathematically. This often makes the study of program distance way more di cult than the corresponding study of program equivalence

Tools and Algorithms for the Construction and Analysis of Systems

This open access two-volume set constitutes the proceedings of the 26th International Conference on Tools and Algorithms for the Construction and Analysis of Systems, TACAS 2020, which took place in Dublin, Ireland, in April 2020, and was held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2020. The total of 60 regular papers presented in these volumes was carefully reviewed and selected from 155 submissions. The papers are organized in topical sections as follows: Part I: Program verification; SAT and SMT; Timed and Dynamical Systems; Verifying Concurrent Systems; Probabilistic Systems; Model Checking and Reachability; and Timed and Probabilistic Systems. Part II: Bisimulation; Verification and Efficiency; Logic and Proof; Tools and Case Studies; Games and Automata; and SV-COMP 2020

Einstein vs. Bergson

On 6 April 1922, Einstein met Bergson to debate the nature of time: is the time the physicist calculates the same time the philosopher reflects on? Einstein claimed that only scientific time is real, while Bergson argued that scientific time always presupposes a living and perceiving subject. On that day, nearly 100 years ago, conflict was inevitable. Is it still inevitable today? How many kinds of time are there

New Realism and Contemporary Philosophy

This open access book advances the current debate in continental realism. In the field of contemporary continental ontology, Speculative Realist thinkers are now grappling with the genealogy of their ideas in the history of modern philosophy. The Speculative Realism movement prompted a debate, criticizing the predominant postmodernist orientation in philosophy, which located its origins in Kantian “correlationism” which supposedly ended the period of early modern naive realist metaphysics by showing that the mind and the outside world can only ever be understood as correlates. The debate over a new kind of realism has attracted many supporters and critics. In order to refocus its specific interpretation of modern philosophy in general and of the Kantian gesture in particular, this volume brings together major authors working on contemporary ontology and historians of ideas. It underlines and illustrates the fact that contemporary continental philosophy is rediscovering its past in original ways by productively re-interpreting some of the key concepts of modern philosophy. The perspectives and accounts of the key concepts of the history of philosophy are different in the views of individual contributors, and sometimes radically so, yet the discussion between contemporary realists and their critics shows that the real battleground of new ideas lies not in developing the philosophical motifs of the end of the 20th century, but rather in rethinking the milestones of modern philosophy. The eBook editions of this book are available open access under a CC BY-NC-ND 3.0 licence on bloomsburycollections.com