Structural and dynamical properties of superfluid helium: a density functional approach

We present a novel density functional for liquid 4He, properly accounting for the static response function and the phonon-roton dispersion in the uniform liquid. The functional is used to study both structural and dynamical properties of superfluid helium in various geometries. The equilibrium properties of the free surface, droplets and films at zero temperature are calculated. Our predictions agree closely to the results of ab initio Monte Carlo calculations, when available. The introduction of a phenomenological velocity dependent interaction, which accounts for backflow effects, is discussed. The spectrum of the elementary excitations of the free surface and films is studied.Comment: 37 pages, REVTeX 3.0, figures on request at [email protected]

Developing Practical Support Tools using Dashboards of Information

International audienceOver 50 years of research on how to support managers’ decision making, numerous solutions have been proposed under a variety of banners, as discussed in the contributions presented in this book. One of the recent terms to have been proposed is Business Inteligence (BI), which aims at leveraging new technologies for the gathering, presentation, and analysis of up-to-date data about the firm’s operations to top management. BI is largely distinguished from previous concepts by its reliance on new platforms and technologies (for instance web technologies) to provide nimbler solutions, more responsive to managerial needs than earlier types of systems. As part of BI, the concept of dashboards of information or digital dashboards has been revisited, notably by software vendors. This chapter explains in detail what dashboards of information are and how to develop them. It considers where business data come from and how to use them to support decision making with a dashboard. Using the concept of cognitive levels, it differentiates between different types of aplications of the dashboard concept. Finally, the chapter aspects of its activities and concludes presents an illustrative case study of a firm seeking to develop a nimble tool for measuring and understanding the key that it is the content of the dashboard and the context in which it is used that are the key elements in the process of developing a dashboard