959 research outputs found
Identification Adaptation Learning, (the science of learningmodels from data)
No full textcontributions by P. Albertos, A.Benveniste, S. Bittanti, M. Campi, G. Cybenko, M. Deistler, B. Delyon, J. Friedman, P-Y. Glorennec, G. Gu, H. Hjalmarsson, A. Lindquist, L. Ljung, A. Juditsky, P. Khargonekar, H. Kimura, P. Kumar, J.M. Maciejowski, G. Picci, R. J. Ober, G. Pflug, P. Rapisarda, W. Scherrer, J. van Schuppen, J. Sjoberg, A.A. Stoorvogel, M. Vidyasagar, Q. Zhan
Representation and Factorization of Discrete-Time Rational All-Pass Functions (vol 62, pg 3262, 2017)
No full textThis article answers a system-theoretic conjecture proposed by Ferrante and Picci (2017). A counterexample to such conjecture is presented along with a modification of the statement, which preserves the essence of the result and is proven to be true
Asymptotic variance of subspace methods by data orthogonalization andmodel decoupling: a comparative analysis
No full textThis is a companion of the paper Chiuso and Picci (2004d) where we do asymptotic error analysis of a weighted PI-MOESP type method and compare accuracy with respect to estimates obtained by customary “joint” subspace methods. The analysis shows that, under certain conditions, methods based on orthogonal decomposition of the input–output data and block-decoupled parametrization perform better than traditional joint-model based methods in the circumstance of nearly parallel regressors
Palliative treatment: selective arterial embolisation for bone metastases.
No full textTreatment options in patients with bone metastases are mostly aimed at palliation. The goals of treatment in these patients are pain control, prevention and treatment of fractures, maintenance of independence and prevention of tumor progression, and improvement of quality of remaining life [1,2]. Traditional palliative treatments include surgery, if the metastatic lesion is accessible, and/or external beam radiation therapy [3,4]. However, all metastatic lesions are progressive, causing bone failure by producing angiogenic and bone-reabsorbing factors [4]. In addition, most, if not all metastatic lesions are hypervascular. Some lesions such as renal and thyroid metastases are highly hypervascular [5–7]. This may cause technical difficulties with respect to the extent of surgery and primary stability for pain relief [2,8,9]
On the multivariate circulant rational covariance extension problem
No full textPartial stochastic realization of periodic processes from finite covariance data leads to the circulant rational covariance extension problem and bilateral ARMA models. In this paper we present a convex optimization-based theory for this problem that extends and modifies previous results by Carli, Ferrante, Pavon and Picci on the AR solution, which have been successfully applied to image processing of textures. We expect that our present results will provide an enhancement of these procedures.</p
Geometric Methods in Stochastic Realization and System Identification
No full textthis paper we discuss some recent advances in modeling and identification of stationary processes. We point out that identification of linear state-space models for stationary signals can be seen as stochastic realization of wide-sense stationary processes in an appropriate background Hilbert space. The geometric theory of stochastic realization developed in the last two decades plays an important role in this interpretation. Identification of models with exogenous inputs in conditions of absence of feedback can also be formulated as a stochastic realization problem. We discuss procedures for constructing minimal state-space models in presence of inputs, based on a generalization of stochastic realization theory for time series and we discuss geometric procedures for identifying (generically) minimal statespace models with inputs. This approach leads to numerical linear algebraic algorithms which have been named "subspace methods" in the literature. It has important advantages over the traditional parametric optimization approach, since it attacks directly the dynamic model building problem by system theoretic methods and leads to procedures which are more transparent and more structured than those traditionally used and found in the literature. 1. Introductio
The technological specialization of countries : an analysis of patent data
No full textNew methods of analysis of patent statistics allow assessing country profiles of technological specialization for the period 1990-2006. We witness a modest decrease in levels of specialization, which we show to be negatively influenced by country size and degree of internationalization of inventive activities
A Dual Nash Game Approach to Discrete-Time H2/H∞ Filtering
No full textThe H2/H∞ filtering problem for discrete-time systems is formulated using a Nash game approach and solved by using duality with the H2/H∞ control problem
Mixed H2/Hinfty Control: The Discrete-Time Case
No full textA stochastic H∞ and a mixed, stochastic, H2 /H∞ control problem for discrete-time systems are considered and solved. Conditions for existence of a solution are derived, based on the solvability of an equivalent minimax problem. In this framework, it is possible to consider at the same time both stochastic and deterministic disturbances highlighting their mutual effects. The controller can be designed by solving a system of three coupled Riccati equations. Such equations display how the H2-type minimization problem and the H∞ - type constraint influence each other
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