11 research outputs found

    Ninth European Powder Diffraction Conference – Prague, September 2-5, 2004

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    Zeitschrift fĂŒr Kristallographie. Supplement Volume 23 presents the complete Proceedings of all contributions to the IX European Powder Diffraction Conference in Prague 2004: Method Development and Application, Instrumental, Software Development, Materials Supplement Series of Zeitschrift fĂŒr Kristallographie publishes Proceedings and Abstracts of international conferences on the interdisciplinary field of crystallography

    Reconstruction of Software Component Architectures and Behaviour Models using Static and Dynamic Analysis

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    Model-based performance prediction systematically deals with the evaluation of software performance to avoid for example bottlenecks, estimate execution environment sizing, or identify scalability limitations for new usage scenarios. Such performance predictions require up-to-date software performance models. This book describes a new integrated reverse engineering approach for the reconstruction of parameterised software performance models (software component architecture and behaviour)

    Innovative Methods and Materials in Structural Health Monitoring of Civil Infrastructures

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    In the past, when elements in sructures were composed of perishable materials, such as wood, the maintenance of houses, bridges, etc., was considered of vital importance for their safe use and to preserve their efficiency. With the advent of materials such as reinforced concrete and steel, given their relatively long useful life, periodic and constant maintenance has often been considered a secondary concern. When it was realized that even for structures fabricated with these materials that the useful life has an end and that it was being approached, planning maintenance became an important and non-negligible aspect. Thus, the concept of structural health monitoring (SHM) was introduced, designed, and implemented as a multidisciplinary method. Computational mechanics, static and dynamic analysis of structures, electronics, sensors, and, recently, the Internet of Things (IoT) and artificial intelligence (AI) are required, but it is also important to consider new materials, especially those with intrinsic self-diagnosis characteristics, and to use measurement and survey methods typical of modern geomatics, such as satellite surveys and highly sophisticated laser tools

    An Adaptive Parameterisation Method for Shape Optimisation Using Adjoint Sensitivities.

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    PhD Theses.Adjoint methods are the most e cient approach to compute the design sensitivities as the entire gradient vector of a single objective function is obtained in a single adjoint system solve. This in turn opens up a wide range of possibilities to parameterise the shape. Most shape parameterisation methods require manual set-up which typically results in a restricted design space. In this work, two parameterisation methods that can be derived automatically from existing information are extended to include adaptive design space in shape optimisation. The node-based method derives parameterisation directly from the computational mesh employed for simulation and normal displacements of the surface grid nodes are taken as design variables. This method o ers the richest design space for shape optimisation. However, this method requires an additional surface regularization method to annihilate high-frequency shape modes. Hence the best achievable design depends on the amount of smoothing applied on the design surface. An improved adaptive explicit surface regularization method is proposed in this thesis to capture superior shape modes in the design process. The NSPCC approach takes CAD descriptions as input and perturbs the control points of the NURBS boundary representation to modify the shape. The adaptive NSPCC method is proposed where the optimisation begins with a coarser design space and adapts to ner parameterisation during the design process. Driven by adjoint sensitivity information the control points on the design surfaces are adaptively enriched using knot insertion algorithm without modifying the shape. Both parameterisation methods are coupled in the adjoint-based shape optimisation process to reduce the total pressure loss of a turbine blade internal cooling channel. Based on analyses regarding the quality of the optima and the rate of convergence of the design process the adaptive NSPCC method outperforms both adaptive node-based and the static NSPCC approach

    GSI Scientific Report 2007 [GSI Report 2008-1]

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    Optimisation of opaque building envelope components with Phase Change Materials

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    The objective of the present thesis is to provide a methodological approach for the design of responsive building envelope components through the application of optimisation analyses. In detail, this approach was applied to opaque building envelope components with Phase Change Materials (PCMs). Since multi-objective optimisation problems generally result in a series of trade-off solutions called Pareto-front, the main focus was to investigate which values assumed by the optimisation variables led to the optimal set of solutions. In this way, the optimisation analysis was used as a tool to gain knowledge on specific problems. After an overview on PCMs and on the application of optimisation analyses to the building envelope for improving the energy efficiency of buildings, three levels of analysis were explored; material level, component level and building level. At the material level, the optimisation approach was applied to estimate the temperature-dependent specific heat curve of PCMs through best-fit of experimental data. Given the measured surface temperatures of a sample as boundary conditions and the known thermo-physical properties of the materials to a numerical model, the curve which minimised the difference between measured and simulated heat fluxes on both faces of the sample was found. At the component level, “equivalent” parameters for the dynamic thermal characterisation of opaque building envelope components with PCM were proposed. Starting from the definition of the traditional dynamic thermal properties according to ISO 13786:2007, a monthly equivalent periodic thermal transmittance and the corresponding time shift were defined by imposing steady-periodic conditions with monthly average external air temperature and solar irradiance profiles while keeping a constant air temperature on the internal side. Then, the monthly equivalent values were synthesised in a unique yearly value by means of a simple average. A parametric model was subsequently developed to describe PCM-enhanced multi-layer walls with simultaneous use of at most two PCMs, and an optimisation analysis was carried out for three locations (Palermo, Torino and Oslo) to find wall layout and PCMs' thermo-physical properties (melting temperature, melting temperature range, latent heat of fusion and thermal conductivity) which minimise yearly equivalent periodic thermal transmittance, overall PCM thickness and thickness of the wall. At the building level, the investigations focused on the application of optimisation analyses for the energy retrofit of office buildings. Three retrofit options on the opaque envelope components were considered in the aforementioned locations; intervention either on the external side of the wall, on the internal side of the wall, or on both sides of the wall. Moreover, either the same retrofit solution for all the walls or a different wall solution for each orientation were considered. In both cases, a maximum of two PCM materials could be selected by the optimisation algorithm. With regard to the objective functions, the problem was faced under two points of view. On one side, optimisations were run with three objectives to minimise the building energy need for heating, cooling and the investment cost. On the other side, the optimisations were performed with two objectives to minimise primary energy consumption and global cost. Only for the climate of Oslo, where heating is mostly electric and no cooling system was adopted, the minimisation objectives were primary energy consumption, global cost and thermal discomfort. Even though a proper optimisation of the thermo-physical properties of PCMs was found to be especially advisable when the operation of the HVAC system implies a non-trivial solution, the results of these analyses allowed to propose a few design guidelines for PCM selection and application. However, for the analysed case studies, PCM prices need to be reduced in order to become a cost-effective retrofit option

    Handbook of Optical and Laser Scanning

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    From its initial publication titled Laser Beam Scanning in 1985 to Handbook of Optical and Laser Scanning, now in its second edition, this reference has kept professionals and students at the forefront of optical scanning technology. Carefully and meticulously updated in each iteration, the book continues to be the most comprehensive scanning resource on the market. It examines the breadth and depth of subtopics in the field from a variety of perspectives. The Second Edition covers: Technologies such as piezoelectric devices Applications of laser scanning such as Ladar (laser radar) Underwater scanning and laser scanning in CTP As laser costs come down, and power and availability increase, the potential applications for laser scanning continue to increase. Bringing together the knowledge and experience of 26 authors from England, Japan and the United States, the book provides an excellent resource for understanding the principles of laser scanning. It illustrates the significance of scanning in society today and would help the user get started in developing system concepts using scanning. It can be used as an introduction to the field and as a reference for persons involved in any aspect of optical and laser beam scanning
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