Abstract
In this paper, a recursive algorithm is presented, based on the CVA subspace identification algorithm. The main idea was to explore the relations between the orthogonal and oblique projections involved and to provide simpler expressions that allowed a recursive version of the algorithm - guaranteeing most of the advantages of this kind of methods, and still improving the numerical efficiency.

Abstract
In this paper, a new approach to estimate matrices B and D, in subspace methods, is provided. The starting point was one method proposed by Van Overschee and De Moor (1996). We have derived new (and simpler) expressions and we found that the original method can be rewritten as a weighted least squares problem, involving the future outputs and inputs and the observability matrix.

Abstract
In this paper we present two subspace identification methods implemented through sequences of modified Householder algorithm. The main idea was to show that subspace identification methods can be represented as sequences of least squares problems and implemented wing QR factorizations. Therefore, it is possible to develop iterative algorithms with most of the advantages of this kind of methods, and still improve the numerical efficiency, in order to deal with real-tme applications and minimize the computational burden.

Abstract

Abstract

Abstract
The in-situ investigation and characterization of ISC'2 experimental site comprised the application of several geophysical borehole, penetration and surface methods, namely S waves high resolution shallow reflection (SHRR), ground penetrating radar (GPR), P and S waves seismic cross-hole (CH), downhole (DII), refraction, electrical resistivity, as well as geotechnical tests, namely SPT, CPT, DMT, among others. The site, located within the campus of Faculty of Engineering of the University of Porto (FEUP), is geologically fortned by an upper layer of heterogeneous residual granite soil overlaying rather weathered granite contacting a gneissic migmatite. Direct and indirect results from some of the referred surveys are compared between them and with some of the available geological and geotechnical information, in particular hereby (Part II), those obtained from SHRR, GPR, and CH seismic tests. The integration of the available information was then used to build a tentative geological interpretation model. One of the objectives of this component of the global study, hereby presented, was to evaluate the possibility of obtaining valid infortnation from a single technique, particularly, S waves shallow reflection.