The Epistemology of Simulation, Computation and Dynamics in Economics Ennobling Synergies, Enfeebling 'Perfection'

Lehtinen and Kuorikoski ([73]) question, provocatively, whether, in the context of Computing the Perfect Model, economists avoid - even positively abhor - reliance on simulation. We disagree with the mildly qualified affirmative answer given by them, whilst agreeing with some of the issues they raise. However there are many economic theoretic, mathematical (primarily recursion theoretic and constructive) - and even some philosophical and epistemological - infelicities in their descriptions, definitions and analysis. These are pointed out, and corrected; for, if not, the issues they raise may be submerged and subverted by emphasis just on the unfortunate, but essential, errors and misrepresentationsSimulation, Computation, Computable, Analysis, Dynamics, Proof, Algorithm

An optical navigation filter simulator for a CubeSat mission to Didymos binary asteroid system

AIDA (Asteroid Impact and Deflection Assessment), is a joint NASA-ESA mission that will operate within 65803 Didymos binary system and whose main purpose is to experiment and investigate the kinetic impact technique for the deviation of the asteroid trajectories in space. HERA, the "mother" satellite designed by ESA, will aim to collect data about the chemical-physical composition of the binary system and about the characteristics of the impact between DART, the bullet-satellite realized and run by NASA, and the minor of the two celestial bodies that compose Didymos, which should occur around October 2022. HERA satellite will carry high-level technology onboard, including some CubeSats. This panorama also includes the DustCube mission, a project proposal for a CubeSat, whose main objective is to assist HERA in the acquisition of data. This thesis, as part of the DustCube project, aims at investigating the autonomous navigation of the CubeSat within the Didymos system, in particular through the development of a navigation filter based on optical observables. By making use of images gathered by a couple of infrared cameras, both LoS and range measurements are retrieved and fed to an Extended Kalman Filter. Results show that, even if implementing a reduced dynamical model within the filter, the expected position accuracy is below the requested 10 meters

Experiments Relevant to the Development of Laser Interferometric Gravitational Wave Detectors

The development of gravitational wave detectors has been in progress for approximately twenty-five years. As yet there has been no clear evidence for the successful detection of such propagating fluctuations in the curvature of spacetime, but the prospects seem good that detectors of sufficient sensitivity to detect gravitational waves of astrophysical origin can be constructed in the near future. The most promising form of detector is the long baseline laser interferometer, and prototypes are being developed at a number of sites around the world. A 10 metre prototype is currently being developed in Glasgow. This thesis is an account of work based on the Glasgow prototype. After an elementary introduction to the theoretical foundations of gravitational waves, various sources of gravitational radiation, the nature of their emitted signal and their strengths are considered. Suitable detectors and their possible sensitivities are reviewed. Noise sources which could limit the sensitivity of laser interferometer detectors and the constraints which these place on the design of the detector are discussed. Since the test masses in an interferometer detector must be freely suspended as pendulums, yet their orientation must be accurately controlled to maintain correct alignment of the optical cavities forming the interferometer, an active orientation control system was developed and installed on the Glasgow prototype. This system provides a high degree of positional and angular stabilisation at low frequencies while leaving the test mass essentially free at high frequencies. Some of the potential limitations and noise sources are noted and their magnitudes calculated. A digital recording system was designed and used to record data from the prototype detector at Glasgow. The effects of the detector's response are analysed and techniques to recover the gravitational wave signal from the recorded data are described. The analysis of some data recorded with this system is then reported. The pulse statistics of the interferometer are analysed and the implications for searches for millisecond pulses of gravitational waves are discussed. The results of a search for periodic signals in the detector output are presented. Various sources of contamination which may be present in the detector output are identified, limitations of the recorded data are noted, and techniques which may be used to reduce the importance of these effects are described

Compressed and distributed least-squares regression: convergence rates with applications to Federated Learning

In this paper, we investigate the impact of compression on stochastic gradient algorithms for machine learning, a technique widely used in distributed and federated learning. We underline differences in terms of convergence rates between several unbiased compression operators, that all satisfy the same condition on their variance, thus going beyond the classical worst-case analysis. To do so, we focus on the case of least-squares regression (LSR) and analyze a general stochastic approximation algorithm for minimizing quadratic functions relying on a random field. We consider weak assumptions on the random field, tailored to the analysis (specifically, expected H\"older regularity), and on the noise covariance, enabling the analysis of various randomizing mechanisms, including compression. We then extend our results to the case of federated learning. More formally, we highlight the impact on the convergence of the covariance $\mathfrak{C}_{\mathrm{ania}}$ of the additive noise induced by the algorithm. We demonstrate despite the non-regularity of the stochastic field, that the limit variance term scales with $\mathrm{Tr}(\mathfrak{C}_{\mathrm{ania}} H^{-1})/K$ (where $H$ is the Hessian of the optimization problem and $K$ the number of iterations) generalizing the rate for the vanilla LSR case where it is $\sigma^2 \mathrm{Tr}(H H^{-1}) / K = \sigma^2 d / K$ (Bach and Moulines, 2013). Then, we analyze the dependency of $\mathfrak{C}_{\mathrm{ania}}$ on the compression strategy and ultimately its impact on convergence, first in the centralized case, then in two heterogeneous FL frameworks

Towards an Aesthetic Epistemology: Transforming Thinking through Cybernetic Epistemology and Anthroposophy

The complexity, subtlety, interlinking, and scale of many problems faced individually and collectively in today's rapidly changing world requires an epistemology--a way of thinking about our knowing--capable of facilitating new kinds of responses that avoid recapitulation of old ways of thinking and living. Epistemology, which implicitly provides the basis for engagement with the world via the fundamental act of distinction, must therefore be included as a central facet of any practical attempts at self/world transformation. We need to change how we think, not just what we think. The new epistemology needs to be of a higher order than the source of the problems we face. This theoretical, transdisciplinary dissertation argues that such a new epistemology needs to be recursive and process-oriented. This means that the thoughts about thinking that it produces must explicitly follow the patterns of thinking by which those thoughts are generated. The new epistemology is therefore also phenomenological, requiring the development of a reflexivity in thinking that recursively links across two levels of order--between content and process. The result is an epistemology that is of (and for) the whole human being. It is an enacted (will-imbued) and aesthetic (feeling-permeated) epistemology (thinking-penetrated) that is sensitive to and integrative of material, soul, and spiritual aspects of ourselves and our world. I call this kind of epistemology aesthetic, because its primary characteristic is found in the phenomenological, mutually fructifying and transformative marriage between the capacity for thinking and the capacity for feeling. Its foundations are brought forward through the confluence of multiple domains: cybernetic epistemology, the esoteric epistemology of anthroposophy (the spiritual science of Rudolf Steiner), and the philosophy of the implicit as developed by Eugene Gendlin. The practice of aesthetic epistemology opens new phenomenal domains of experience, shedding light on relations between ontology and epistemology, mind and body, logic and thinking, as well as on the formation (and transformation) of identity, the immanence of thinking in world-processes, the existence of different types of logic, and the nature of beings, of objects, and most importantly of thinking itself and its relationship to spirit

Explorando ferramentas de modelação digital, aumentada e orientada por dados em engenharia e design de produto

Tools are indispensable for all diligent professional practice. New concepts and possibilities for paradigm shifting are emerging with recent computational technological developments in digital tools. However, new tools from key concepts such as “Big-Data”, “Accessibility” and “Algorithmic Design” are fundamentally changing the input and position of the Product Engineer and Designer. After the context introduction, this dissertation document starts by extracting three pivotal criteria from the Product Design Engineering's State of the Art analysis. In each one of those criteria the new emergent, more relevant and paradigmatic concepts are explored and later on are positioned and compared within the Product Lifecycle Management wheel scheme, where the potential risks and gaps are pointed to be explored in the experience part. There are two types of empirical experiences: the first being of case studies from Architecture and Urban Planning — from the student's professional experience —, that served as a pretext and inspiration for the experiments directly made for Product Design Engineering. First with a set of isolated explorations and analysis, second with a hypothetical experience derived from the latter and, finally, a deliberative section that culminate in a listing of risks and changes concluded from all the previous work. The urgency to reflect on what will change in that role and position, what kind of ethical and/or conceptual reformulations should exist for the profession to maintain its intellectual integrity and, ultimately, to survive, are of the utmost evidence.As ferramentas são indispensáveis para toda a prática diligente profissional. Novos conceitos e possibilidades de mudança de paradigma estão a surgir com os recentes progressos tecnológicos a nível computacional nas ferramentas digitais. Contudo, novas ferramentas originadas sobre conceitos-chave como “Big Data”, “Acessibilidade” e “Design Algorítmico” estão a mudar de forma fundamental o contributo e posição do Engenheiro e Designer de Produto. Esta dissertação, após uma primeira introdução contextual, começa por extrair três conceitos-eixo duma análise ao Estado da Arte actual em Engenharia e Design de Produto. Em cada um desses conceitos explora-se os novos conceitos emergentes mais relevantes e paradigmáticos, que então são comparados e posicionados no círculo de Gestão de Ciclo de Vida de Produto, apontando aí potenciais riscos e falhas que possam ser explorados em experiências. As experiências empíricas têm duas índoles: a primeira de projetos e casos de estudo de arquitetura e planeamento urbanístico — experiência em contexto de trabalho do aluno —, que serviu de pretexto e inspiração para as experiências relacionadas com Engenharia e Design de Produto. Primeiro com uma série de análises e experiências isoladas, segundo com uma formulação hipotética com o compêndio dessas experiências e, finalmente, com uma secção de reflexão que culmina numa série de riscos e mudanças induzidas do trabalho anterior. A urgência em refletir sobre o que irá alterar nesse papel e posição, que género de reformulações éticas e/ou conceptuais deverão existir para que a profissão mantenha a sua integridade intelectual e, em última instância, sobreviva, são bastante evidentes.Mestrado em Engenharia e Design de Produt

After dualism

Prepared for discussion at a conference sponsored by the Gulbenkian Foundation on Challenges to Dominant Modes of Knowledge: Dualism, SUNY Binghamton, 3-4 November 2006.This talk concerns issues of time and dualism in academic theory and the real world. The dualism in question concerns people and things and the habit of thinking of them as distinct ontological orders. In contrast, I explore various projects of ‘ontological theatre’—projects that variously thematise nondualist engagements and stage them in a variety of fields including brain science, the science of complex systems, psychiatry, management, politics, spirituality, the arts, music, architecture, and so on. The examples are largely drawn from the history of cybernetics, and locate the engagements in question as constituted in reciprocal becomings in time