3 resultados para OAIS reference model for an open archival information system
em Repositório Científico da Universidade de Évora - Portugal
Resumo:
Teknova have 2D steady-state models of the calciner but wish, in the long term, to have a 3D model that can also cover unsteady conditions, and can can model the loss of axisymmetry that someties occurs. Teknova also wish to understand the processes happening around the tip of the upper electrode, in particular the formation of a lip on it and the the shape of the empty region below it. The Study Group proposed potential models for the degree of graphitization, and for the granular flow. Also the Study Group considered the upper electrode in detail. The proposed model for the lip formation is by sublimation of carbon from the hottest parts of the furnace with redeposition in the region around the electrode, which may stick particles onto the electrode surface. In this model the region below the electrode would be a void, roughly a vertex-down conical cavity. The electric field near the lower rim of the electrode will then have a singularity and so the most intense heating of the charge will be around the rim. We conjecture that the reason why the lower electrode lasts so much longer than the upper is that it is not adjacent to a cavity like this, and therefore does not have a singularity in the field.
Resumo:
This paper presents an integrated model for an offshore wind energy system taking into consideration a contribution for the marine wave and wind speed with perturbations influences on the power quality of current injected into the electric grid. The paper deals with the simulation of one floating offshore wind turbine equipped with a PMSG and a two-level converter connected to an onshore electric grid. The use of discrete mass modeling is accessed in order to reveal by computing the THD on how the perturbations of the captured energy are attenuated at the electric grid injection point. Two torque actions are considered for the three-mass modeling, the aerodynamic on the flexible part and on the rigid part of the blades. Also, a torque due to the influence of marine waves in deep water is considered. PI fractional-order control supports the control strategy. A comparison between the drive train models is presented.
Resumo:
In an organisation any optimization process of its issues faces increasing challenges and requires new approaches to the organizational phenomenon. Indeed, in this work it is addressed the problematic of efficiency dynamics through intangible variables that may support a different view of the corporations. It focuses on the challenges that information management and the incorporation of context brings to competitiveness. Thus, in this work it is presented the analysis and development of an intelligent decision support system in terms of a formal agenda built on a Logic Programming based methodology to problem solving, complemented with an attitude to computing grounded on Artificial Neural Networks. The proposed model is in itself fairly precise, with an overall accuracy, sensitivity and specificity with values higher than 90 %. The proposed solution is indeed unique, catering for the explicit treatment of incomplete, unknown, or even self-contradictory information, either in a quantitative or qualitative arrangement.