The Bak-Sneppen Model on Scale-Free Networks

We investigate by numerical simulations and analytical calculations the Bak-Sneppen model for biological evolution in scale-free networks. By using large scale numerical simulations, we study the avalanche size distribution and the activity time behavior at nodes with different connectivities. We argue the absence of a critical barrier and its associated critical behavior for infinite size systems. These findings are supported by a single site mean-field analytic treatment of the model.Comment: 5 pages and 3 eps figures. Final version appeared in Europhys. Let

Restructurable Controls

Restructurable control system theory, robust reconfiguration for high reliability and survivability for advanced aircraft, restructurable controls problem definition and research, experimentation, system identification methods applied to aircraft, a self-repairing digital flight control system, and state-of-the-art theory application are addressed

Open access to educational resources in energy and sustainability: Usability evaluation prototype for repositories

The purpose of this paper is to show a PhD dissertation research plan, which aims to assess whether the users’ experience of users to perform various tasks in an open access repository, increases by integrating Discovery Tools. The tasks to perform by the users are management and information design, dissemination and searches of open educational resources (OER) of sustainability energy. This research aims to develop a usability evaluation prototype which will offer new insights in the design of the information architecture. In the first stage, the criteria will be selected to measure the level of usability of the tasks to evaluate and develop the analysis of the current interactive design of the web repository. In the second stage, will consist of measure, once implemented the Discovery Tools in the web repository and check the usability level increase in relation with the criteria. In this paper you could find aspects as the motivations and the context in which it will develop this research, state of the art, hypothesis, research objectives, aspects of the methodology of the research, developed under the method of mixed layout, the current an expected contribution, the results and the validation and dissertation status. The results will contribute for detect new criteria and parameters for provide flexible interfaces, specifically for the web repositories, which are a part of the technological ecosystem of the scientific activity

Simultaneous Water Vapor and Dry Air Optical Path Length Measurements and Compensation with the Large Binocular Telescope Interferometer

The Large Binocular Telescope Interferometer uses a near-infrared camera to measure the optical path length variations between the two AO-corrected apertures and provide high-angular resolution observations for all its science channels (1.5-13 $\mu$m). There is however a wavelength dependent component to the atmospheric turbulence, which can introduce optical path length errors when observing at a wavelength different from that of the fringe sensing camera. Water vapor in particular is highly dispersive and its effect must be taken into account for high-precision infrared interferometric observations as described previously for VLTI/MIDI or the Keck Interferometer Nuller. In this paper, we describe the new sensing approach that has been developed at the LBT to measure and monitor the optical path length fluctuations due to dry air and water vapor separately. After reviewing the current performance of the system for dry air seeing compensation, we present simultaneous H-, K-, and N-band observations that illustrate the feasibility of our feedforward approach to stabilize the path length fluctuations seen by the LBTI nuller.Comment: SPIE conference proceeding