Models for near-rigid shape matching are typically based on distance-related features, in order to infer matches that are consistent with the isometric assumption. However, real shapes from image datasets, even when expected to be related by “almost isometric” transformations, are actually subject not only to noise but also, to some limited degree, to variations in appearance and scale. In this...

Mediator systems aim to provide an unified global data schema over distributed heterogeneous structured and semi-structured data sources. These systems must deal with limitations on the query capabilities of the sources. This paper introduces a new framework for representing source query capability along with the algorithms needed to compute the query capabilities of the global schema from sour...

Ever-growing data volumes demand for storage systems beyond current file systems abilities, particularly, a powerful querying capability. With the rise of XML, the database community has been challenged by semi-structured data processing, enhancing their field of activity. Since file systems are structured hierarchically they can be mapped to XML and as such stored in and queried by an XML-awar...

This paper describes a method for creating structure from heterogeneous sources, as part of a concept base, or other information database. ‘Concept trees’ can grow from the heterogeneous sources when correct and consistent sequences of concepts are presented. The method maintains the key requirement of generality, allowing it to be used as part of a generic framework. The nature of the method a...

Tree-dependent component analysis (TCA) is a generalization of independent component analysis (ICA), the goal of which is to model the multivariate data by a linear transformation of latent variables, while latent variables fit by a tree-structured graphical model. In contrast to ICA, TCA allows dependent structure of latent variables and also consider non-spanning trees (forests). In this pape...

A pair-copula construction is a decomposition of a multivariate copula into a structured system, called regular vine, of bivariate copulae or pair-copulae. The standard practice is to model these pair-copulae parametri-cally, which comes at the cost of a large model risk, with errors propagating throughout the vine structure. The empirical pair-copula proposed in the paper provides a nonparamet...

A multivariate structured total least squares problem is considered, in which the extended data matrix is partitioned into blocks and each of the blocks is Toeplitz/Hankel structured, unstructured, or noise free. Two types of numerical solution methods for this problem are proposed: i) standard local optimization methods in combination with efficient evaluation of the cost function and its firs...

We develop a higher-order generalization of the LQ decomposition and show that this decomposition plays an important role in likelihood-based estimation and testing for separable, or Kronecker structured, covariance models, such as the multilinear normal model. This role is analogous to that of the LQ decomposition in likelihood inference for the multivariate normal model. Additionally, this hi...

Permutation based XML-conscious compressors permute the input document to improve the compression ratio and support efficiency of operations, such as queries or updates. One such compressor, XSAQCT, uses the properties of the permuted document, called an annotated tree, to these operations. This paper provides the formal background for the definition of an of D. It also provides an algorithm fo...

A line of research is presented aimed at specifying both logical and navigational aspects of semi-structured data sources such as Web sites through the unifying notion of schema. Gracefully supporting schemata that are huge or subject to change, the WG-Log language allows for a uniform representation of queries and views, the latter expressing customized access structures to site information. A...