1,847 research outputs found

    ENHANCING CLOUD SYSTEM RUNTIME TO ADDRESS COMPLEX FAILURES

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    As the reliance on cloud systems intensifies in our progressively digital world, understanding and reinforcing their reliability becomes more crucial than ever. Despite impressive advancements in augmenting the resilience of cloud systems, the growing incidence of complex failures now poses a substantial challenge to the availability of these systems. With cloud systems continuing to scale and increase in complexity, failures not only become more elusive to detect but can also lead to more catastrophic consequences. Such failures question the foundational premises of conventional fault-tolerance designs, necessitating the creation of novel system designs to counteract them. This dissertation aims to enhance distributed systems’ capabilities to detect, localize, and react to complex failures at runtime. To this end, this dissertation makes contributions to address three emerging categories of failures in cloud systems. The first part delves into the investigation of partial failures, introducing OmegaGen, a tool adept at generating tailored checkers for detecting and localizing such failures. The second part grapples with silent semantic failures prevalent in cloud systems, showcasing our study findings, and introducing Oathkeeper, a tool that leverages past failures to infer rules and expose these silent issues. The third part explores solutions to slow failures via RESIN, a framework specifically designed to detect, diagnose, and mitigate memory leaks in cloud-scale infrastructures, developed in collaboration with Microsoft Azure. The dissertation concludes by offering insights into future directions for the construction of reliable cloud systems

    Nonperturbative Aspects of Quantum Field Theory in Curved Spacetime

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    Quantum field theory in curved spacetime is perhaps the most reliable framework in which one can investigate quantum effects in the presence of strong gravitational fields. Nevertheless, it is often studied by means of perturbative treatments. In this thesis, we aim at using the functional renormalization group -- a nonperturbative realization of the renormalization group -- as a technique to describe nonperturbative quantum phenomena in curved spacetimes. The chosen system is an Unruh--DeWitt particle detector coupled to a scalar quantum field. We discuss how to formulate such a system in terms of an action and how one can compute its renormalization group flow in the case of an inertial detector in flat spacetime, for simplicity. We learn, however, that the results are divergent in the limit in which the detector's energy gap vanishes. Possible workarounds are discussed at the end. This thesis also presents a review of quantum field theory in curved spacetimes by means of the algebraic approach, although it assumes no previous experience with functional analysis. Hence, it fills a pedagogical gap in the literature. Furthermore, we also review the functional renormalization group and derive the Wetterich equation assuming a general field content that might include both bosonic and fermionic fields. Such a derivation is also hardly found in pedagogical introductions available in the high energy physics literature.Comment: MSc thesis defended at the Federal University of ABC (Brazil) on 28 April 2023. xxiv + 152 pages, 22 figure

    Historical Burdens on Physics

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    When learning physics, one follows a track very similar to the historical path of the evolution of this science: one takes detours, overcomes superfluous obstacles and repeats mistakes, one learns inappropriate concepts and uses outdated methods. In the book, more than 200 articles present and analyze such obsolete concepts methods. All articles have the same structure: 1. subject, 2. deficiencies, 3. origin, 4. disposal. The articles had originally appeared as columns in various magazines. Accordingly, we had tried to write them in an easily understandable way

    (b2023 to 2014) The UNBELIEVABLE similarities between the ideas of some people (2006-2016) and my ideas (2002-2008) in physics (quantum mechanics, cosmology), cognitive neuroscience, philosophy of mind, and philosophy (this manuscript would require a REVOLUTION in international academy environment!)

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    (b2023 to 2014) The UNBELIEVABLE similarities between the ideas of some people (2006-2016) and my ideas (2002-2008) in physics (quantum mechanics, cosmology), cognitive neuroscience, philosophy of mind, and philosophy (this manuscript would require a REVOLUTION in international academy environment!

    On astrophysical solutions in the constructive gravity program and cosmological tests for weakly birefringent spacetime

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    Via gravitational closure [DĂĽ+18]; [Wol22]; [Due20]; [Wie18] could show, how gravitational theories based on the matter content of spacetime can be systematically constructed. While this successfully reproduces general relativity for metric spacetimes, finding a solution for the simplest generalization of Maxwell electrodynamics with a vacuum birefringence allowing, area-metric structure has in general not been possible so far. For highly symmetric FLRW spacetimes a metric, as well as an area-metric solution could be derived [Due20]; [Fis17]. Based on this result, the constructive gravity program will be applied for spherically symmetric, stationary metric spacetimes. Furthermore, an according ansatz is worked out for area-metric geometries, and it is discussed which difficulties arise in finding a corresponding solution. Furthermore, the Etherington-duality is violated in the case of weakly area-metric gravitation [Sch+17]; [Ale20b]; [SW17], and this violation will be investigated with weak gravitational lensing experiments. The observable is the surface brightness, which is, however, heavily influenced by astrophysical processes like physical interaction of galaxies with tidal fields. Beyond that, it is studied how galaxies also get bent due to tidal interactions and how strong this effect is compared to its analog in gravitational lensing

    2010 GREAT Day Program

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    SUNY Geneseo’s Fourth Annual GREAT Day. This file has a supplement of three additional pages, linked in this record.https://knightscholar.geneseo.edu/program-2007/1004/thumbnail.jp

    Reassessing Gombrich’s Theory of Illusion for the 21st Century

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    ERNST GOMBRICH produced a well-known classic of the so-called “theory of illusion” (Ziska, 2018, p. 2), aiming to tell “the story of art” through its relation with illusion and visua l“schemata.” His famous work, Art and Illusion (1960/2014) gained wide popularity, first appearing in 1960 and continuing to be republished until today. This has created a paradox: on the one hand, readers and modern thinkers are interested in Gombrich’s writings (Hopkins, 2003; Lopes, 2005; Veldeman, 2008; Tullmann, 2016), but on the other, they do not use his concepts to evaluate the processes occurring in today’s social, ontological, and artistic domains. Indeed, the question of artistic skill has been significantly relegated to a secondary position in the modern debate, while the notions of ideas, manifests, and concepts have come to the fore (Haftmann et al., 1965, p. 203). Moreover, we have witnessed a transformation from “the human of skill” and limited capabilities into “the human of concepts” and expansion, where self-acting technologies work for our good (or bad). Take, for example, deepfakes, Artificial Intelligence (AI), Machine Learning (ML), and Generative Adversarial Networks (GAN). For good reason, the contemporary philosopher Chiara Bottici (2019) warns us that there is a significant reliance on perception and image-type representations by public society, so much so that losing grasp of real things is a potential danger. In this regard, is it wise to set aside Gombrich’s ideas and perceive them exclusively as a relic of their time, or have we just not yet found the right place for them in the current debates? Did Gombrich detect some deeper meanings than just the reinterpretation of art history through the lens of the illusional and solving the “riddle of style”? In order to answer these questions, this research reassesses Gombrich’s Theory of Illusion with regard to the techno-social and political environment of today’s image-making. By detecting and building connections between the ideas of Gombrichand contemporary philosophers of mind, it is hoped that we will be better equipped to attend to the novel features of the art world and its practices which have emerged in a post-computational society. It appears that we may have already reached a world in which the gap between image and nature is collapsing, leaving us hanging in uncertainty. This is a world in which the differences between the imaginable, illusional, abstract, and real are significantly more complex and blurred. That is why it is essential and crucial to address this very question now, especially when any idea is dependent on representation and at the same time is complicated by imaginal spaces, imaginal objects, and imaginal politics
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