Fluid Dynamics Without Fluids

This chapter will discuss some interesting real applications where Fluid Dynamics equations found fruitful appliances without dealing with "strictly speaking" fluids. In particular, thanks to the large set of analyses performed over different kinds of fluids in different operating and boundary conditions, a wide range of Computational Fluid Dynamics algorithms flourished tackling different aspects, from convergence rate, to stability according to the discretization, to multigrid and linearization problems. This robust and thorough background, both on the- oretical and on practical aspects, made Computational Fluid Dynamics (CFD) appealing also to other sciences and applications where Fluid Dynamics equations, or similar equations very close to them, can be useful in describing complex phenomena not related to fluids. Some applications that will be discussed concern, e.g., Geometry of liquid snowflakes whose con- tour is growing steered by curvature, staring from a circle. Furthermore Image Restoration and Segmentation can also benefit from CFD since a set of evolutionary algorithms, based on level-set curvature flow equations, plays a fundamental role in steering active contours or snakes through the noise present in the image till the complete warping of the desired framed object. Also in this case advanced techniques like Ghost Fluids Method for two competing fluids dynamics can be used to separate different objects in images. Other interesting appli- cations that will be described concern applicability of CFD to surface extraction from cloud of points. This is a common problem when complex clouds of points, representing 3D objects or scenes are obtained by laser scanners or multi-camera vision systems. These points represent unambiguous features from corners or sharp edges and the final 3D closed surface must fit on these points smoothly interpolating empty space between them. Also in this case CFD can provide useful tools to define the evolution of a 3D surface representing the border between two competing fluids, one representing the "inside" and the other the "outside" of the object itself. The two fluids evolution will stop when surface sticks on all the 3D points: the viscosity of the two fluids will control the smoothness of this surface that will wrap the cloud and tur- bulence is used to model injection into grooves or narrow holes. This chapter will also discuss another interesting application of CFD to robotic navigation in complex environments where we are looking for the best path, both in terms of length and distance from objects, through a set of obstacles, different terrains traversability or path slope. Also in this case an imaginary fluid with a predefined viscosity floods from the robot position through the whole environ- ment, its front evolution speed, accordingly to CFD, will be slower in narrow passages and, once it reaches the target, it will define the easiest way

sistema per la verifica di una corretta procedura di igiene orale

Sistema per la verifica di una corretta procedura di igiene orale caratterizzato dal fatto di comprendere: una telecamera per visualizzare il viso di una persona che si spazzola i denti con uno spazzolino comprensivo di un marker; mezzi di elaborazione per localizzare i punti salienti di detto viso di una persona; mezzi di elaborazione per localizzare detto spazzolino; mezzi di elaborazione per inseguire i movimenti di detti punti salienti; mezzi di elaborazione per inseguire i movimenti di detto spazzolino; mezzi di elaborazione per calcolare il movimento relativo tra detto viso e detto spazzolino; mezzi di verifica per verificare che detto movimento relativo tra detto viso e detto spazzolino sia conforme ad un movimento relativo prefissato

Aggregate effect on the concrete cone capacity of an undercut anchor under quasi-static tensile load

In the last decades, fastening systems have become an essential part of the construction industry. Post-installed mechanical anchors are frequently used in concrete members to connect them with other load bearing structural members, or to attach appliances. Their performance is limited by the concrete related failure modes which are highly influenced by the concrete mix design. This paper aims at investigating the effect that different aggregates used in the concrete mix have on the capacity of an undercut anchor under tensile quasi-static loading. Three concrete batches were cast utilising three different aggregate types. For two concrete ages (28 and 70 days), anchor tensile capacity and concrete properties were obtained. Concrete compressive strength, fracture energy and elastic modulus are used to normalize and compare the undercut anchor concrete tensile capacity employing some of the most widely used prediction models. For a more insightful comparison, a statistical method that yields also scatter information is introduced. Finally, the height and shape of the concrete cones are compared by highly precise and objective photogrammetric means

The relationship between the concepts of aesthetics and community in recent art theory and criticism

This thesis explores the relationship between ideas of aesthetics and community in recent art theory and criticism in the context of a resurgence of artistic practices emphasising participation, social engagement and collaboration. These two concepts have been regarded with suspicion in the critical and theoretical trends that came to prominence in the nineteen sixties. Aesthetics was seen as the province of politically disengaged elites with a vested interest in stripping art of any concrete relationship to the social field, while community was often associated with a nostalgic longing for an idealised, conflict-free social order that never existed. However, in recent times the two notions have been subjected to serious reconsideration by a range of influential art theorists, curators and critics. This revival has, at least in part, occurred in response to the resurgence of participatory and socially engaged art since the nineteen nineties. Responding to these developments, this thesis argues that the aesthetics/community nexus lies at the core of Immanuel Kant’s Critique of Judgement and that this foundational text of Western aesthetic philosophy can be reinterpreted to both clarify and refigure the terms of the current debate about socially inclined art. The continuing relevance of Kant’s thought can be evinced by his influence on many, and often radically contrasting, theoretical positions including Clement Greenberg’s formalism, Thierry de Duve’s account of the Duchampian turn, Jean-François Lyotard’s postmodern sublime and, more recently, Jacques Rancière’s theory of aesthetics and politics. This study conducts a comparative analysis of texts by the aforementioned thinkers, as well as selected writings on art and community by Martin Heidegger. The examination of these philosophical reflections is interwoven with a discussion of writings by prominent analysts of the recent social turn in art such as Claire Bishop, Grant Kester, Nicolas Bourriaud, Boris Groys, Nato Thompson, Miwon Kwon, Suzanne Lacy and Claire Doherty. My investigation of these and other relevant texts proposes that recent discourses and curatorial practices focused on the relation between art and community suggest an indirect Heideggerian influence that co-exists with more explicit references to Kant’s third Critique. Ultimately I propose the possibility of a synthesis of the seemingly divergent Kantian and Heideggerian perspectives. Specifically, I contend that Kant’s idea of ‘play’ and Heidegger’s concept of ‘strife’ are based on a similar vision of the aesthetic as openness to the indeterminate. My study concludes that this conception of the aesthetic provides an interpretive paradigm able to address the theoretical as well as ethical challenges posed by new forms of socially engaged art

Does impartial reasoning matter in economic decisions? An experimental result about distributive (un)fairness in a production context

The Rawlsian social contract presents the veil of ignorance as a thought experiment that should induce agents to behave more fairly within a distributive context. This study uses a laboratory experiment to test the effect of actual reasoning behind the veil, as a moral cue, in a Dictator Game with taking and production. The main hypothesis claims that reflection from an impartial perspective should lead subjects to put themselves in the shoes of who could be the least benefited. Against our expectations, the impact of the moral cue was null and no attempt to rebalance the unjustified differences was observed