Optimizing the performance of self-organizing feature maps like the Kohonen map involves the choice of the output space topology. We present a topographic product which measures the preservation of neighborhood relations as a criterion to optimize the output space topology of the map with regard to the global dimensionality DA as well as to the dimensions in the individual directions. We test t...

An important question in ensemble based data assimilation scheme is how to configure our observations to correctly capture the important features in either our atmospheric or oceanic models given a set of ensembles. In this paper a systematic approach for effective sensor placement is formulated to evaluate how to target our observations. This method is based on a criterion of Shannon informati...

An hybrid segmentation method for color images is presented in this work. It combines 2D histogram clustering to produce segmentation maps fused together providing an initial unsupervised clustering of the dominant colors of the image. Region information is then used and a novel technique is introduced to simplify the Region Adjacency Graph by merging candidate regions until the stabilization o...

We propose a method of quantifying the degree of frustration manifested by spatially local interactions in protein biomolecules. This method of localization smoothly generalizes the global criterion for an energy landscape to be funneled to the native state, which is in keeping with the principle of minimal frustration. A survey of the structural database shows that natural proteins are multipl...

In total variation denoising, one attempts to remove noise from a signal or image by solving a nonlinear minimization problem involving a total variation criterion. Several approaches based on this idea have recently been shown to be very eeective, particularly for denoising functions with discontinuities. This paper analyzes the convergence of an iterative method for solving such problems. The...

The Dotplotting method has been widely used for text segmentation for its merits in detecting lexical repetition in global context. However, a theoretical analysis of its segmentation criterion function finds several deficiencies. The original function can not make full use of the text structure features and does not suit the text segmentation task very well. We propose an improved model (MMD m...

In this paper, we are concerned with strong solutions to the Cauchy problem for the incompressible Magnetohydrodynamic equations. By the Galerkin method, energy method and the domain expansion technique, we prove the local existence of unique strong solutions for general initial data, develop a blow-up criterion for local strong solutions and prove the global existence of strong solutions under...

The main objective of this study is to develop an alternative criterion for modeshape classification, as the currently available one, MAC (Modal Assurance Criteria), is only a vector correlation representing modeshape similarities. This new method is developed to provide a set of features (Fourier Descriptors) for comparing modeshapes with “local” similarities of higher interest than “global” s...