Accurate macroscale modelling of spatial dynamics in multiple dimensions

Developments in dynamical systems theory provides new support for the macroscale modelling of pdes and other microscale systems such as Lattice Boltzmann, Monte Carlo or Molecular Dynamics simulators. By systematically resolving subgrid microscale dynamics the dynamical systems approach constructs accurate closures of macroscale discretisations of the microscale system. Here we specifically explore reaction-diffusion problems in two spatial dimensions as a prototype of generic systems in multiple dimensions. Our approach unifies into one the modelling of systems by a type of finite elements, and the `equation free' macroscale modelling of microscale simulators efficiently executing only on small patches of the spatial domain. Centre manifold theory ensures that a closed model exist on the macroscale grid, is emergent, and is systematically approximated. Dividing space either into overlapping finite elements or into spatially separated small patches, the specially crafted inter-element/patch coupling also ensures that the constructed discretisations are consistent with the microscale system/PDE to as high an order as desired. Computer algebra handles the considerable algebraic details as seen in the specific application to the Ginzburg--Landau PDE. However, higher order models in multiple dimensions require a mixed numerical and algebraic approach that is also developed. The modelling here may be straightforwardly adapted to a wide class of reaction-diffusion PDEs and lattice equations in multiple space dimensions. When applied to patches of microscopic simulations our coupling conditions promise efficient macroscale simulation.Comment: some figures with 3D interaction when viewed in Acrobat Reader. arXiv admin note: substantial text overlap with arXiv:0904.085

The philosophy of European Law with "chaos out of order" set-up and functioning

In reconsideration of the composition and operation of European law, it is the description of its underlying mentality that may cast best light on the query whether European law is the extension of domestic laws or a sui generis product. As to its action, European law is destructive upon the survival of traditions of legal positivism, for it recalls post modern clichés rather. Like a solar system with planets, it is two-centred from the beginning, commissioning both implementation and judicial check to member states. As part of global post modernism, a) European law stems from artificial reality construction freed from particular historical experience and, indeed, anything given hic et nunc. By its operation, b) it dynamises large structures and sets in motion that what is chaos itself. It is owing to reconstructive human intent solely that any outcome can at all be seen as fitting to some ideal of order, albeit neither operation nor daily management strives for implementing any systemicity. This is the way in which the European law becomes adequate reflection of the underlying (macro) economic basis, which it is to serve as superstructure. Accordingly, c) the entire construct is operated (as integrated into one well-working unit) within the framework of an artificially animated dynamism. With its “order out of chaos” philosophy it assures member states’ standing involvement and competition, achieving a flexibly self-adapting (and unprecedentedly high degree of) conformity

Final Report of the DAUFIN project

DAUFIN = Data Assimulation within Unifying Framework for Improved river basiN modeling (EC 5th framework Project

Intervenção estrutural e construtiva em edifícios antigos: enquadramento metodológico

The main purpose of this article is to present and discuss intervention methodologies, focusing on structural and constructive  work undertaken on old buildings of common architecture that are considered to be of cultural interest. Lying at the origin of this paper is the understanding that many of the interventions currently being made on such buildings are typically façadist in nature, frequently involving the complete reconstruction of the buildings themselves and showing a total disregard for the cultural values that their actual materials and traditional construction techniques confer upon them. A brief review will first be made of the main recommendations currently proposed for the conservation and rehabilitation of old buildings, while a general intervention methodology will also be established. In this way, an attempt will be made to discuss the various approaches and procedures that are commonly adopted in practice, in keeping with the nature of the different buildings that are subject to intervention, the aim being to present a summary of some recent studies that have recognised the need for a specific approach to the group of old buildings of common architecture that display a significant cultural value. O presente artigo tem como principal propósito apresentar e discutir metodologias de intervenção, focalizadas nos domínios estrutural e construtivo, em edifícios antigos de arquitetura corrente portadores de valor cultural. Na sua gênese, está o entendimento de que grande parte da intervenção que atualmente impende sobre este edificado, se caracteriza pela sua natureza fachadista, frequentemente de reconstrução integral do edifício e com total desconsideração dos valores culturais que os próprios materiais e técnicas construtivas tradicionais que o materializam lhe aportam. Procura-se, assim, através de uma breve revisão das principais recomendações hoje estabelecidas em matéria de conservação e reabilitação de edifícios antigos e da correspondente definição de uma metodologia genérica de intervenção, discutir diferentes abordagens e procedimentos correntes na prática, em correspondência com a natureza dos edifícios intervencionados, para, reconhecida a necessidade de uma aproximação específica para o grupo dos edifícios antigos correntes com valor cultural, apresentar sumariamente alguns estudos recentemente conduzidos, visando a discussão e o desenvolvimento de soluções e abordagens que facilitem a adoção de boas práticas nas respectivas obras de reabilitação, tomando como referência o caso particular da Casa Burguesa do Porto, do século XIX

Multidomain Spectral Method for the Helically Reduced Wave Equation

We consider the 2+1 and 3+1 scalar wave equations reduced via a helical Killing field, respectively referred to as the 2-dimensional and 3-dimensional helically reduced wave equation (HRWE). The HRWE serves as the fundamental model for the mixed-type PDE arising in the periodic standing wave (PSW) approximation to binary inspiral. We present a method for solving the equation based on domain decomposition and spectral approximation. Beyond describing such a numerical method for solving strictly linear HRWE, we also present results for a nonlinear scalar model of binary inspiral. The PSW approximation has already been theoretically and numerically studied in the context of the post-Minkowskian gravitational field, with numerical simulations carried out via the "eigenspectral method." Despite its name, the eigenspectral technique does feature a finite-difference component, and is lower-order accurate. We intend to apply the numerical method described here to the theoretically well-developed post-Minkowski PSW formalism with the twin goals of spectral accuracy and the coordinate flexibility afforded by global spectral interpolation.Comment: 57 pages, 11 figures, uses elsart.cls. Final version includes revisions based on referee reports and has two extra figure

Knowledge-based fault detection using time-frequency analysis

This work studies a fault detection method which analyzes sensor data for changes in their characteristics to detect the occurrence of faults in a dynamic system. The test system considered in this research is a Boeing-747 aircraft system and the faults considered are the actuator faults in the aircraft. The method is an alternative to conventional fault detection method and does not rely on analytical mathematical models but acquires knowledge about the system through experiments. In this work, we test the concept that the energy distribution of resolution than the windowed Fourier transform. Verification of the proposed methodology is carried in two parts. The first set of experiments considers entire data as a single window. Results show that the method effectively classifies the indicators by more that 85% as correct detections. The second set of experiments verifies the method for online fault detection. It is observed that the mean detection delay was less than 8 seconds. We also developed a simple graphical user interface to run the online fault detection

Sharpening the Cutting Edge: Corporate Action for a Strong, Low-Carbon Economy

Outlines lessons learned from early efforts to create a low-carbon economy, current and emerging best practices, and next steps, including climate change metrics, greenhouse gas reporting, effective climate policy, and long-term investment choices