This paper reformulates, generalizes and investigates the stability of the modified Prony algorithm introduced by Osborne (1975), with special reference to rational and exponential fitting. The algorithm, originally for exponential functions, is generalized to the least squares fitting of any function which satisfies a linear homogeneous difference equation. Using the difference equation formul...

Sharp features in manufactured and designed objects require particular attention when reconstructing surfaces from unorganized scan point sets using moving least squares (MLS) fitting. It’s an inherent property of MLS fitting that sharp features are smoothed out. Instead of searching for appropriate new fitting functions our approach computes a modified local point neighborhood so that a standa...

The increasingly request for the maintenance of architectural heritage has led in last decades to extensive use System Identification (SI) techniques Structural Health Monitoring (SHM) purposes. These proved be useful tools assessing state conservation built environment and its behaviour operating conditions. In particular, historical masonry structures infrastructures present several compellin...

Computation of the broadband antenna impedance behavior requires wideband lumped equivalent circuit. This work aims to provide a comprehensive study circuit models over broad frequency ranges for Internet Things (IoT) applications using multiple approaches. The first approach is Foster approximation, which based on antenna-simulated scattering parameters and data. second concerns vector-fitting...

We develop an approach to subspace system identification using multiple data records and present a simple rank-based test for the adequacy of these data for fitting the unique linear, noise-free, dynamic model of prescribed state-vector, input-vector and output-vector dimensions. The approach is motivated by the prospect of sorting through archives of operational data and extracting a sequence ...

In this paper a relativistic quantum theory introduced by de Groot and Ruijgrok in 1975, is used as a quark model in momentum space. The complete spectrum, with the exception of the selfconjugate light unflavoured mesons, is calculated. The potential used consists of an one-gluon-exchange (OGE) part and a confining part. For the confining part a relativistic generalization of the linear plus co...