90,141 research outputs found
Developing Information Power Grid Based Algorithms and Software
This exploratory study initiated our effort to understand performance modeling on parallel systems. The basic goal of performance modeling is to understand and predict the performance of a computer program or set of programs on a computer system. Performance modeling has numerous applications, including evaluation of algorithms, optimization of code implementations, parallel library development, comparison of system architectures, parallel system design, and procurement of new systems. Our work lays the basis for the construction of parallel libraries that allow for the reconstruction of application codes on several distinct architectures so as to assure performance portability. Following our strategy, once the requirements of applications are well understood, one can then construct a library in a layered fashion. The top level of this library will consist of architecture-independent geometric, numerical, and symbolic algorithms that are needed by the sample of applications. These routines should be written in a language that is portable across the targeted architectures
Parallel computing aided design of earthing systems for electrical substations in non homogeneous soil models
[Abstract] An accurate design of grounding systems is essential to assure the safety of the persons, to protect the equipment and to avoid interruptions in the power supply. In order to attain these targets, the equivalent electrical resistance of the system and the potential distribution on the earth surface in fault conditions are necessary to compute. In this paper, it is presented a numerical approach for grounding analysis embedded in stratified soils and its implementation in a high-perfomance parallel computer. The feasibility of this system is shown with its application to the analysis of a real grounding system in a layered soil.Ministerio de EducaciĂłn y Cultura; 1FD97-010
Multiscale thermo-mechanical analysis of multi-layered coatings in solar thermal applications
Solar selective coatings can be multi-layered materials that optimize the solar absorption while reducing thermal radiation losses, granting the material long-term stability. These layers are deposited on structural materials (e.g., stainless steel, Inconel) in order to enhance the optical and thermal properties of the heat transfer system. However, interesting questions regarding their mechanical stability arise when operating at high temperatures. In this work, a full thermo-mechanical multiscale methodology is presented, covering the nano-, micro-, and macroscopic scales. In such methodology, fundamental material properties are determined by means of molecular dynamics simulations that are consequently implemented at the microstructural level by means of finite element analyses. On the other hand, the macroscale problem is solved while taking into account the effect of the microstructure via thermo-mechanical homogenization on a representative volume element (RVE). The methodology presented herein has been successfully implemented in a reference problem in concentrating solar power plants, namely the characterization of a carbon-based nanocomposite and the obtained results are in agreement with the expected theoretical values, demonstrating that it is now possible to apply successfully the concepts behind Integrated Computational Materials Engineering to design new coatings for complex realistic thermo-mechanical applications.Peer ReviewedPostprint (author's final draft
Anomalous elasticity in a disordered layered XY model
We investigate the effects of layered quenched disorder on the behavior of
planar magnets, superfluids, and superconductors by performing large-scale
Monte-Carlo simulations of a three-dimensional randomly layered XY model. Our
data provide numerical evidence for the recently predicted anomalously elastic
(sliding) intermediate phase between the conventional high-temperature and
low-temperature phases. In this intermediate phase, the spin-wave stiffness
perpendicular to the layers vanishes in the thermodynamic limit while the
stiffness parallel to the layers as well as the spontaneous magnetization are
nonzero. In addition, the susceptibility displays unconventional finite-size
scaling properties. We compare our Monte-Carlo results with the theoretical
predictions, and we discuss possible experiments in ultracold atomic gases,
layered superconductors and in nanostructures.Comment: 6 pages, 4 eps figures included, proceedings of FQMT11, final version
as publishe
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