Spatial variability in the exchange of energy and moisture is a key control on numerous atmospheric, hydrologic, and environmental processes. Using observations made on fair weather days during the 2002 International H2O Project, four methods for quantifying the spatial variability of surface fluxes are investigated. The first two methods utilize applied statistical techniques to describe the s...

For an ensemble of iso-contours in multi-dimensional scalar fields, we present new methods to a) visualize their dominant spatial patterns of variability, and b) to compute the conditional probability of the occurrence of a contour at one location given the occurrence at some other location. We first show how to derive a statistical model describing the contour variability, by representing the ...

We describe a method for analyzing the shape variability of images, called geometric PCA. Our approach is based on the use of deformation operators to model the geometric variability of images around a reference mean pattern. This leads to a new algorithm for estimating shape variability. Some numerical experiments on real images are proposed to highlight the benefits of this approach. The cons...

In this work the use of statistical techniques will be approached for segmentation of SAR images, with the purpose of ship detection, being used RADARSAT images of the Brazilian coast. As described in Rocha et al (2001) and Rocha and Stech (2003), a specific software for ship detection was developed where, based on Eldhuset (1996), Vachon et al (1997), Oliver and Quegan (1998), Zaart et al (199...

In this paper we derive a probabilistic model for recognition based on local descriptors and spatial relations between these descriptors. Our model takes into account the variability of local descriptors, their saliency as well as the probability of spatial conngura-tions. It is structured to clearly separate the probability of point-wise correspondences from the spatial coherence of sets of co...

Quasi-biennial cycles are often reported in climate studies. The interannual El Niño Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) are two phenomena containing quasi-periodicities of approximately 2.5 and 2.2 years. It is known that ENSO affects corn yield throughweather patterns, NAO affects surface temperature and cloudiness, and surface temperature, rainfall, and radiation...

In the field of cluster analysis, most of existing algorithms assume that each feature of the samples plays a uniform contribution for cluster analysis. Considering different features with different importance, feature-weight assignment can be regarded as a special case of feature selection. That is, the feature assigned a value in the interval [0, 1] indicating the importance of that feature, ...

Improving technologies create a “buy or wait?” dilemma. In this paper, we consider repeat purchases when the consumer faces an infinite stream of new technologies. We develop a probabilistic model and focus on the role of “more variability” on the process of technological innovation. Similar to real options models, we find that variability in the technological process increases value for the co...