11,002 research outputs found

    Applications of artificial neural nets in structural mechanics

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    A brief introduction to the fundamental of Neural Nets is given, followed by two applications in structural optimization. In the first case, the feasibility of simulating with neural nets the many structural analyses performed during optimization iterations was studied. In the second case, the concept of using neural nets to capture design expertise was studied

    Tackling Exascale Software Challenges in Molecular Dynamics Simulations with GROMACS

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    GROMACS is a widely used package for biomolecular simulation, and over the last two decades it has evolved from small-scale efficiency to advanced heterogeneous acceleration and multi-level parallelism targeting some of the largest supercomputers in the world. Here, we describe some of the ways we have been able to realize this through the use of parallelization on all levels, combined with a constant focus on absolute performance. Release 4.6 of GROMACS uses SIMD acceleration on a wide range of architectures, GPU offloading acceleration, and both OpenMP and MPI parallelism within and between nodes, respectively. The recent work on acceleration made it necessary to revisit the fundamental algorithms of molecular simulation, including the concept of neighborsearching, and we discuss the present and future challenges we see for exascale simulation - in particular a very fine-grained task parallelism. We also discuss the software management, code peer review and continuous integration testing required for a project of this complexity.Comment: EASC 2014 conference proceedin

    Theories about architecture and performance of multi-agent systems

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    Multi-agent systems are promising as models of organization because they are based on the idea that most work in human organizations is done based on intelligence, communication, cooperation, and massive parallel processing. They offer an alternative for system theories of organization, which are rather abstract of nature and do not pay attention to the agent level. In contrast, classical organization theories offer a rather rich source of inspiration for developing multi-agent models because of their focus on the agent level. This paper studies the plausibility of theoretical choices in the construction of multi-agent systems. Multi-agent systems have to be plausible from a philosophical, psychological, and organizational point of view. For each of these points of view, alternative theories exist. Philosophically, the organization can be seen from the viewpoints of realism and constructivism. Psychologically, several agent types can be distinguished. A main problem in the construction of psychologically plausible computer agents is the integration of response function systems with representational systems. Organizationally, we study aspects of the architecture of multi-agent systems, namely topology, system function decomposition, coordination and synchronization of agent processes, and distribution of knowledge and language characteristics among agents. For each of these aspects, several theoretical perspectives exist.

    Material Sight: A Sensorium for Fundamental Physics

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    Often our attempts to connect to the spatial and temporal scales of fundamental physics - from the subatomic to the multiverse - provoke a form of perceptual vertigo, especially for non-scientists. When we approach ideas of paralysing abstraction through the perceptual range of our sensing bodies, a ‘phenomenological dissonance’ can be said to be invoked, between material presence and radical remoteness. This relational dynamic, between materiality and remoteness, formed the conceptual springboard for 'Material Sight' (2016-2018), a research project based at three world-leading facilities for fundamental physics, that brought to fruition a body of photographic objects, film works and immersive soundscape that re-presented the spaces of fundamental physics as sites of material encounter. The research was premised on a paradoxical desire to create a sensorium for fundamental physics, asking if photography, film and sound can embody the spaces of experimental science and present them back to scientists and non-scientists alike, not as illustrations of the technical sublime but as sites of phenomenological encounter. This article plots the key conceptual coordinates of 'Material Sight' and looks at how the project’s methodological design – essentially the production of knowledge through the 'act of looking' – emphatically resisted the gravitational pull of art to be instrumentalised as an illustrative device within scientific contexts
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