On the Lagrange and Markov Dynamical Spectra for Geodesic Flows in Surfaces with Negative Curvature

We consider the Lagrange and the Markov dynamical spectra associated to a geodesic flow on a surface of negative curvature. We show that for a large set of real functions on the unit tangent bundle and for typical metrics with negative curvature and finite volume, both the Lagrange and the Markov dynamical spectra have non-empty interior

Timed Consistent Network Updates

Network updates such as policy and routing changes occur frequently in Software Defined Networks (SDN). Updates should be performed consistently, preventing temporary disruptions, and should require as little overhead as possible. Scalability is increasingly becoming an essential requirement in SDN. In this paper we propose to use time-triggered network updates to achieve consistent updates. Our proposed solution requires lower overhead than existing update approaches, without compromising the consistency during the update. We demonstrate that accurate time enables far more scalable consistent updates in SDN than previously available. In addition, it provides the SDN programmer with fine-grained control over the tradeoff between consistency and scalability.Comment: This technical report is an extended version of the paper "Timed Consistent Network Updates", which was accepted to the ACM SIGCOMM Symposium on SDN Research (SOSR) '15, Santa Clara, CA, US, June 201

Devicing future populations: Problematizing the relationship between quantity and quality of life

Taking as point of departure the claim that, in late modern societies, there has been shift from a focus on producing measures of life and death towards metrics of health and disability, this paper investigates how, through what means and processes was this transition achieved. It proposes that such questions can be addressed by analysing the transcripts and sociotechnical network of a meeting held at the United States Senate on July 15th 1983 to assess the validity and sensitivity of life expectancy forecasts. The paper analyses how members of the Hearing transformed a weakly articulated set of differing life expectancy projections into a controversy about the issue of vitality and health in populations. Analysis of the Hearing proceedings suggests that ‘calculative devices’ played a generative role in problematizing the relationship between forms of expertise, calculative procedures, data infrastructures and specific expectations of the effect of technology on health and longevity. The paper details empirically that this re-composition was possible through a collective investigation – an opening up – of key instruments in the management of populations in ‘insurance societies’