A modular modeling approach to simulate interactively multibody systems with Baumgarte/Uzawa formulation

International audienceIn this paper, a modular modeling approach of multibody systems adapted to interactive simulation is presented. This work is based on the study of the stability of two Differential Algebraic Equations solvers. The first one is based on the acceleration-based augmented Lagrangian formulation and the second one on the Baumgarte formulation. We show that these two solvers give the same results and have to satisfy the same criteria to stabilize the algebraic constraint acceleration error. For a modular modeling approach, we propose to use the Baumgarte formulation and an iterative Uzawa algorithm to solve external constraint forces. This work is also the first step to validate the concept of two types of numerical components for Object-Oriented Programming

Sculpture and the contested ground of public and private space

Through applied practice and historical research, this studio-led doctoral project seeks to identify the intrinsic differences and mutual interdependencies of private and public art.  By analysing the tensions between the rigid constraints of sculpture in the public sphere and the aesthetic flexibility and freedom of the private studio - this research shows how sculpture creates spaces for innovation and reflection in complex and contested urban sites.  In this context art has the potential to act as a conduit between individuals and their community, as a material site of social communication across time and place in which ancient antecedents of the sacred and profane remain, to this day, detectable and relevant.   The research follows a studio process-driven framework, narrating how I have negotiated the contested ground of public and private space. It follows the design and production of specific artworks for both domains, with each process analysed in the five chapters of the dissertation. Starting with a small sculptural work depicting an event in social history, my findings on context and the social, material fabric of the city, lead in the next chapter to the development and completion of a major site-specific, public sculptural relief.  Designed to commemorate the personal and public social achievement of those who engaged with the site, it is also representative of wider social contexts. The social complexities of relations between local use of the site and the broader historical context were explored in a public work that I examine from its design and commission, through to its completion.  From the models used for this larger public work, questions arose concerning art-based solutions to figural representation at key intersections of everyday exchanges between the individual and society. These were explored in an extended series of personal, and experimental figurative sketch models.  In many ways, the intimacy of these maquettes, as well as research on votive practices, became fundamental to the design for a final major commission for Cabrini Hospital, commemorating St Frances Xavier Cabrini, in which the `contested ground' was the sense of sacred and the body, in both the public and private realms.  Finally, the research takes a wider perspective through comparative analysis of two contemporary public sculptures in urban contexts: Callum Morton's Monument Park of 2015, and Gillian Wearing's Statue of Dame Millicent Fawcett, 2018. These large-scale works are analysed in relation to research for my own small studio works and to a number of small scaled works by the Swiss artists Peter Fischli and David Weiss Suddenly This Overview, completed between 1981-2012 This research has revealed that the ground of contestation between private and public domains is not simply an actual, material, and spatial one, but also a complex socio-political domain.  I position art as an intermediary in this field of production and social meaning as a process which not only simply reveals the contested ground of sculpture but also requires negotiation within it.  This innovative perspective provides a significant contribution to art in the contemporary field, and particularly to the potential of sculpture and its contribution to urban life

How not to return to normal

In a March 2020 article published in Le Monde, Bruno Latour defined the Covid-19 emergency as "the big rehearsal" for the larger disaster to come: one that extends to all forms of life on Earth. The ongoing crisis, in his eyes, becomes both a risk and an opportunity to trial and develop new action plans necessary for the continuation of life. "The pandemic is a portal," wrote author Arundhati Roy a few days later, calling for a more equitable and sustainable post-pandemic future. The pandemic is an opportunity for un-learning and changing direction, particularly in how we approach risk and disaster. The dominant narrative for politicians and the media, however, is one of “returning to normal” as soon as possible, bouncing back, relying on established models of resilience based on the management of economic risk. They are also rehearsing, or modelling, worst- or best-case scenarios. Artists, designers, and institutions are shaping discourses around the growing extinguishment of our resources, but also performing, visualising, simulating and modelling responses to possible risks and imagining resilience differently. Design and art can foster new visions, pilot new modes of communication and knowledge sharing, and drive the interdisciplinary collaborations necessary to address common issues. This panel explores ways in which art and design practices can be mobilized to transform current approaches to risk and disaster in imaginative, sustainable and equitable ways. The papers selected for this session reflect a need to reassess, reframe, and reimagine the roles of museums, art and design, and thus contribute to a space for critical reflection to inform action, strategy, and practices. It is important to remember that our fields are far from immune from being complicit in the creation and reinforcement of the kinds of inequalities and injustices that have been made even more unmistakably clear in the last year: as Sasha Costanza-Shock, author of the book Design Justice, has pointed out, designers are ‘often unwittingly reproducing the existing structure of [...] who's going to benefit the most and who's going to be harmed the most by the tools or the objects or the systems or the buildings or spaces that we're designing.’ The urge to respond in an emergency, whether it's a design challenge in the context of COVID 19 or exhibition on climate change, requires space for critical thinking, inclusive conversation and production. This necessity comes across on the three papers brought together for this panel, and in the opening presentation by Emily Candela and Francesca Cavallo

Object oriented design of an interactive mechanism simulation system - Clodion

Mechanical system simulation software is of fundamental importance to computer aided design in mechanical engineering Such software systems considerably reduce turn around time and have applications in various industries like automative, aerospace and general machinery. A number of mechanical simulation systems are commercially available. However. many of these systems are legacy systems, not necessarily with modern graphical user interface techniques, and also not necessarily designed with newer simulation algorithms or robustness considerations. In this paper we describe the design of a. interactive mechanical system simulation package - Clodion. The package has been designed using object oriented design, with careful use of software structuring and also user interface design principles. The design of Clodion has a number of innovative features in the form of its class hierarchy specifically designed for mechanical systems, its event propagation design methodology and its visualization and other utilities. We also present some results which show the user interaction scheme as well. (C) 1999 .

Wellesley College Bulletin [1986-1987]

https://repository.wellesley.edu/catalogs/1084/thumbnail.jp

Handbook for estimating the socio-economic and environmental effects of disasters.

Taken from Introduction: Disasters have a major impact on the living conditions of the population, the economic performance of the countries or regions affected, and on environmental assets and services, with consequences that go beyond the short term and in some cases even irreversibly impact economic and social structures and the environment. In the case of industrialized countries, disasters caused huge damage to the large stock of accumulated capital, whereas losses of human life are limited thanks, among other factors, to the availability of effective early warning and evacuation systems as well as better urban planning and the application of more strict building codes and standards. In developing countries, on the other hand, the number of deaths is usually high because of greater vulnerability brought about by the lack or inadequacy of forecast and evacuation programs; and although losses of capital might be smaller in absolute terms when compared to those in developed countries, their relative weight and overall impact tend to be very significant,1 even affecting sustainability. Disasters may have natural origins or be man-made. However, their consequences derive from a combination of both processes; that is to say, from human interaction with nature and her cycles or systems. Not only do disasters occur frequently around the world, but it would seem that their incidence and intensity have been increasing in recent years. They cause the loss of many lives, directly and indirectly (primarily or secondarily), affect large segments of the population, and cause significant damage to the environment and large-scale economic and social harm