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Moncalieri, Italy

Malago L.,Shinshu University | Pistone G.,Collegio Carlo Alberto
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2015

We discuss the optimization of the stochastic relaxation of a real-valued function, i.e., we introduce a new search space given by a statistical model and we optimize the expected value of the original function with respect to a distribution in the model. From the point of view of Information Geometry, statistical models are Riemannian manifolds of distributions endowed with the Fisher information metric, thus the stochastic relaxation can be seen as a continuous optimization problem defined over a differentiable manifold. In this paper we explore the second-order geometry of the exponential family, with applications to the multivariate Gaussian distributions, to generalize second-order optimization methods. Besides the Riemannian Hessian, we introduce the exponential and the mixture Hessians, which come from the dually flat structure of an exponential family. This allows us to obtain different Taylor formulæ according to the choice of the Hessian and of the geodesic used, and thus different approaches to the design of second-order methods, such as the Newton method. © Springer International Publishing Switzerland 2015. Source


Malago L.,University of Milan | Matteucci M.,Polytechnic of Milan | Pistone G.,Collegio Carlo Alberto
2013 IEEE Congress on Evolutionary Computation, CEC 2013 | Year: 2013

The geometric framework based on Stochastic Relaxation allows to describe from a common perspective different model-based optimization algorithms that make use of statistical models to guide the search for the optimum. In this paper Stochastic Relaxation is used to provide theoretical results on Estimation of Distribution Algorithms (EDAs). By the use of Stochastic Relaxation we show how the estimation of the fitness model by least squares linear regression corresponds to the estimation of the natural gradient. This equivalence allows to simultaneously perform model selection and robust estimation of the natural gradient. Finally, we interpet Linear Programming relaxation as an example of Stochastic Relaxation, with respect to the regular gradient. © 2013 IEEE. Source


O'Dwyer C.,Collegio Carlo Alberto
Journal of Aging Studies | Year: 2013

Numerous studies have indicated that a "psycho-social" person-centered care approach, involving the delivery of a compassionate, respectful model of care, leads to a high quality of life, particularly for older people living in residential care. This has prompted policy-makers to endorse this approach. Yet, some commentators have argued that the model of person-centered care in official government policies equates to a "consumer-based" rather than a psycho-social approach, as it focuses solely on offering service-users more choice and on promoting independence. However, as such arguments are made in the absence of any empirical analysis, it is unclear both whether such a distinction exists in practice, and, if so, how this alternative model developed. This study explores the development of minimum standards for residential care settings for older people in Ireland in order to address this gap in our understanding of person-centered care. Findings confirm that a consumer-driven model of person-centered care underpins the Irish Standards; residential care is portrayed as a hotel-like service and residents as discerning consumers, which may be unsuitable for older people in residential care with limited capacity to make key choices. Analysis indicates that this model can be seen both as an extension of consumer-driven policies endorsed by many neo-liberal governments, and also of policy-makers' fears of losing their autonomy when they reach the "Fourth Age". This study is particularly illuminating, given the similarities between the Irish care system with England, Scotland, Wales, Northern Ireland and Australia. © 2013 Elsevier Inc. Source


Lawson C.,Collegio Carlo Alberto | Lawson C.,University of Turin | Lawson C.,City University London
Journal of Technology Transfer | Year: 2013

This paper provides evidence that university-industry collaboration is important for turning commercial opportunities into patents. The results suggest that researchers who receive a large share of research grants from industry have a higher propensity to file a patent. Small dissemination grants generally exert a positive effect, whether they come from industry or not. It also finds that these interactions do not increase the number of industry owned patents alone but benefit universities' commercialisation efforts in general. © 2012 Springer Science+Business Media New York. Source


Pistone G.,Collegio Carlo Alberto
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

The differential-geometric structure of the set of positive densities on a given measure space has raised the interest of many mathematicians after the discovery by C.R. Rao of the geometric meaning of the Fisher information. Most of the research is focused on parametric statistical models. In series of papers by author and coworkers a particular version of the nonparametric case has been discussed. It consists of a minimalistic structure modeled according the theory of exponential families: given a reference density other densities are represented by the centered log likelihood which is an element of an Orlicz space. This mappings give a system of charts of a Banach manifold. It has been observed that, while the construction is natural, the practical applicability is limited by the technical difficulty to deal with such a class of Banach spaces. It has been suggested recently to replace the exponential function with other functions with similar behavior but polynomial growth at infinity in order to obtain more tractable Banach spaces, e.g. Hilbert spaces. We give first a review of our theory with special emphasis on the specific issues of the infinite dimensional setting. In a second part we discuss two specific topics, differential equations and the metric connection. The position of this line of research with respect to other approaches is briefly discussed. © 2013 Springer-Verlag. Source

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