Gradiometer Response Analysis for Current Multipole Sources
The paper presents an analytical study on the first order gradiometer effects for current multipoles as biomagnetic field sources. A tensor representation of the field expansion up to the current octupole is given and applied for the multipole description of an elementary source model. The sensitivity of first order gradiometers to the higher order poles is analysed and evaluated.
In this paper, the problems of measuring similarity in LDA face space using different metrics and fusing the associated classifiers are considered. A few similarity measures used in different pattern recognition applications, including the recently proposed Gradient Direction (GD) metric are reviewed. An automatic parameter selection algorithm is then proposed for optimising the GD metric. In extensive experimentation on the BANCA database, we show that the optimised GD metric outperforms the other metrics in various conditions. Moreover, we demonstrate that by combining the GD metric and seven other metrics in the decision level using Support Vector Machines, the performance of the resulting decision making scheme consistently improves.