Paris Dauphine University

About: Paris Dauphine University is a education organization based out in Paris, France. It is known for research contribution in the topics: Population & Approximation algorithm. The organization has 1766 authors who have published 6909 publications receiving 162747 citations. The organization is also known as: Paris Dauphine & Dauphine.

Eigenvector dynamics: General theory and some applications.

Abstract: We propose a general framework to study the stability of the subspace spanned by P consecutive eigenvectors of a generic symmetric matrix H0 when a small perturbation is added. This problem is relevant in various contexts, including quantum dissipation (H0 is then the Hamiltonian) and financial risk control (in which case H0 is the assets' return covariance matrix). We argue that the problem can be formulated in terms of the singular values of an overlap matrix, which allows one to define an overlap distance. We specialize our results for the case of a Gaussian orthogonal H0, for which the full spectrum of singular values can be explicitly computed. We also consider the case when H0 is a covariance matrix and illustrate the usefulness of our results using financial data. The special case where the top eigenvalue is much larger than all the other ones can be investigated in full detail. In particular, the dynamics of the angle made by the top eigenvector and its true direction defines an interesting class of random processes.

Opening the Black Box of System Usage: User Adaptation to Disruptive IT

Abstract: According to Benbasat and Barki (2007), systems usage has remained a black box in spite of the fact that the construct lies at the heart of a host of studies in the field. We know very little about how exactly users cope with information technology (IT), especially disruptive IT. To answer such questions, we grounded our current work in Beaudry and Pinsonneault's Coping Model of User Adaptation (2005; CMUA), a model that explains user strategies appraising an IT event. These strategies are a response to threats and opportunities embedded in the IT event and are impacted by the level of control users have over the situation. In the current study, following CMUA, we develop and test measures for a deeper understanding of systems usage and user adaptation to IT through a 2 × 2 laboratory experiment. Overall, we found strong support for the CMUA model.

French Economic Evaluations of Influenza and Influenza Vaccination

Abstract: The cost-of-illness studies of influenza performed in France for the years 1985 and 1989 have shown that the major economic consideration is the respective sizes of indirect and direct costs. Depending on the point of view (from the perspective of National Health Insurance or the societal perspective) and the method used for measuring indirect costs, it was estimated that they could be between 1.5 and 9 times higher than direct costs. A cost-benefit study of influenza vaccination for the employed adult population showed that vaccination is a cost-saving strategy, although this was also contingent upon the problems associated with measuring indirect benefits as well as the effectiveness rate of vaccination in real conditions.