We are happy to present the papers of the 10th International Conference on Ontologies DataBases, and Applications of Semantics, ODBASE 2011, held in Heraklion, Crete (Greece), in October 2011. The ODBASE conference series provides a forum for research on the use of ontologies and data semantics in novel applications, and continues to draw a highly diverse body of researchers and practitioners b...

The problem of estimating the direction of arrivals (DOA) of narrowband sources impinging on a uniform circular array is considered. We present a method that uses as input the values of a small number of uniformly spaced beams and apply a model-fitting approach taking into account the statistical properties of the beams. The approach, which is called the “global matched filter,” fits simultaneo...

Signal cancellation is a serious problem in adaptive nulling. The problem arises when the actual direction of arrival of the signal is slightly off the assumed direction of arrival. The adaptive algorithms consider the actual signal a jammer as the direction of arrival is not exactly specified. In this paper, it is shown how to prevent signal cancellation when the direction of arrival is not kn...

Using the centro-symmetry property of uniform linear array (ULA), we propose an algorithm that combines the weighted l2;1 minimization with the unitary transformation to improve the performance of DOA estimation. Exploiting the result of the unitary transformation, more credible weights can be obtained and the jointly sparse constraint can be further enhanced. Moreover, the unitary transformati...

This paper proposes a method for estimating the direction of arrival (DOA) of multiple source signals for an underdetermined situation, where the number of sources N exceeds the number of sensors M (M < N). Some DOA estimation methods have already been proposed for underdetermined cases. However, since most of them restrict their microphone array arrangements, their DOA estimation ability is li...

Hexagonal arrays are widely used in practice but have received less attention in the optimum array processing literature. In this paper, we show how unitary ESPRIT can be applied to hexagonal arrays for direction-of-arrival (DOA) estimation. The resulting estimates exhibit good threshold behavior, and are close to the Cramer-Rao bound above threshold. We also show how to use spatial smoothing i...

The Royal Netherlands Meteorological Institute has continuously operated an outdoor atmospheric infrasound array containing 37 pairs of particle velocity sensors (Microflown) and 6 pressure sensors in the north of the Netherlands in the fall of 2008. As initial results, we detected transients caused by distant aircrafts and calculated their Direction of Arrival (DOA). A nearby sound-source, pro...

We investigate DOA (direction-of-arrival) estimation for arbitrary linear arrays, where the antenna positions may be non-integer values in half-wavelength units. We introduce an approach based on arbitrary virtual linear arrays to resolve manifold ambiguity and estimate DOA's in the superior case. These virtual arrays adopt the set of covariance lags speci ed by the original array and so themse...

A wideband off-grid model is proposed to represent dictionary mismatch under the compressive sensing framework exploiting difference co-arrays. A group sparsity based off-grid method is proposed for underdetermined wideband direction of arrival (DOA) estimation which provides improved performance over the existing group sparsity based method with a same search grid. A two-step approach is then ...

Subspace based estimates, i.e. estimates obtained by exploiting the orthogonality between a sample subspace and a parameter-dependent subspace have proved useful in many applications, including array processing and system identification. The purpose of this contribution is to complement the already available theoretical results generally obtained in specific contexts. We discuss the generalizat...