116 resultados para Artificial Lift
Resumo:
The origins of artificial neural networks are related to animal conditioning theory: both are forms of connectionist theory, which in turn derives from the empiricist philosophers' principle of association. The parallel between animal learning and neural nets suggests that interaction between them should benefit both sides.
Resumo:
In shallow waters, such as those found close to berth structures, the wash from a manoeuvring ship’s propeller can cause erosion of the seabed. This erosion can be increased if the wash intersects a berth structure. A number of researchers have undertaken model studies and used regression analysis to develop predictive relationships for the scouring action. This paper presents an experimental investigation with Artificial Neural Networks (ANN’s), used to analyse the results. The purpose of using ANN’s was to examine the prediction accuracy of the Networks in comparison with previous regression analysis methods. ANN’s were found to provide a more accurate method of predicting propeller wash scour than the equations presented by previous investigators.
Resumo:
Sensitive Artificial Listeners (SAL) are virtual dialogue partners based on audiovisual analysis and synthesis. Despite their very limited verbal understanding, they intend to engage the user in a conversation by paying attention to the user’s emotions and non- verbal expressions. The SAL characters have their own emotionally defined personality, and attempt to drag the user towards their dom- inant emotion through a combination of verbal and non-verbal ex- pression. The demonstrator shows the publicly available, fully au- tonomous SAL system.
Resumo:
Research has been undertaken to investigate the use of artificial neural network (ANN) techniques to improve the performance of a low bit-rate vector transform coder. Considerable improvements in the perceptual quality of the coded speech have been obtained. New ANN-based methods for vector quantiser (VQ) design and for the adaptive updating of VQ codebook are introduced for use in speech coding applications.
Resumo:
An experimental artificial reefwas constructed in Strangford Lough, Northern Ireland as part of trials to regenerate damaged biogenic reefs formed by the horse mussel Modiolus modiolus. Experimental reef plots were constructed using Pecten maximus shell as cultch. Clumps of live adult M. modiolus were translocated from nearby natural reefs into cultchwith a high profile (elevated cultch), cultch with a lowprofile (flattened cultch), as well as directly into the seafloor. The aim of the study was to test the hypothesis that translocated mussel clumps would increase habitat complexity thus accelerating community succession and enhancing natural recruitment of M. modiolus spat. These effects were predicted to be greater on elevated cultch due to greater protection from
predators and increased accessibility to food resources. Within the artificial reef array the translocated clumps had a significant positive effect on recruitment compared to cultch without mussels with average densities of spat settled on the translocated M. modiolus clumps ranging from 100 to 200 individuals m-2 compared to 4 to 52 spat m-2 on cultch without mussels. Recruitment of M. modiolus spat was also significantly higher on translocated horse mussels when compared to natural reefs where densities of 8–36 spat m-2 were recorded.
Reef elevation appeared to provide some degree of protection from predators but differences in translocated M. modiolus survival on the different elevation treatments were not significant. In total, 223 taxa were recorded 12 months after reef construction. The presence of translocated clumps ofM. modiolus was the main driver of the increases in faunal diversity and species abundance. Application of objective criteria to assess the performance of artificial reefs suggested that translocation of M. modiolus clumps alone achieved most of the restoration objectives. Consequently this pilot study demonstrates a straightforward and realistic intervention technique that could be used to kick start the regeneration and expansion of impacted mussel and similar biogenic reefs elsewhere.
Resumo:
Intertwining planar spirals arranged in doubly periodic arrays enables a substantially subwavelength response of the unit cell smaller than 1/40 of wavelength with large fractional bandwidths. These properties are important for application at low frequencies, conformal curved surfaces, or with compact radiators. It is shown that interleaving counter-wound spiral arms extended into adjacent unit cells dramatically increase the array equivalent capacitance while reducing the inductance. A coplanar waveguide (CPW) model has been developed to analytically estimate the equivalent capacitance and inductance of intertwined spiral array elements in terms of their geometrical parameters. The proposed CPW model is shown to provide an accurate prediction of the fundamental resonance frequency and can be instrumental in the design of the arrays for a specified frequency response. © 2012 IEEE.