6,226 research outputs found
Formation of star-forming clouds from the magnetised, diffuse interstellar medium
Molecular clouds, the birthplaces of stars in galaxies, form dynamically from
the diffuse atomic gas of the interstellar medium (ISM). The ISM is also
threaded by magnetic fields which have a large impact on its dynamics. In
particular, star forming regions must be magnetically supercrit- ical in order
to accomodate gas clumps which can collapse under their own weight. Based on a
parameter study of three dimensional magneto-hydrodyamical (MHD) simulations,
we show that the long-standing problem of how such supercritical regions are
generated is still an open issue.Comment: Invited contribution to the NIC proceedings 2016 for the John von
Neumann-Institut f\"ur Computing (NIC) Symposium 201
Energy challenges for ICT
The energy consumption from the expanding use of information and communications technology (ICT) is unsustainable with present drivers, and it will impact heavily on the future climate change. However, ICT devices have the potential to contribute signi - cantly to the reduction of CO2 emission and enhance resource e ciency in other sectors, e.g., transportation (through intelligent transportation and advanced driver assistance systems and self-driving vehicles), heating (through smart building control), and manu- facturing (through digital automation based on smart autonomous sensors). To address the energy sustainability of ICT and capture the full potential of ICT in resource e - ciency, a multidisciplinary ICT-energy community needs to be brought together cover- ing devices, microarchitectures, ultra large-scale integration (ULSI), high-performance computing (HPC), energy harvesting, energy storage, system design, embedded sys- tems, e cient electronics, static analysis, and computation. In this chapter, we introduce challenges and opportunities in this emerging eld and a common framework to strive towards energy-sustainable ICT
Creating Tailored and Adaptive Network Services with the Open Orchestration C-RAN Framework
Next generation wireless communications networks will leverage
software-defined radio and networking technologies, combined with cloud and fog
computing. A pool of resources can then be dynamically allocated to create
personalized network services (NSs). The enabling technologies are abstraction,
virtualization and consolidation of resources, automatization of processes, and
programmatic provisioning and orchestration. ETSI's network functions
virtualization (NFV) management and orchestration (MANO) framework provides the
architecture and specifications of the management layers. We introduce OOCRAN,
an open-source software framework and testbed that extends existing NFV
management solutions by incorporating the radio communications layers. This
paper presents OOCRAN and illustrates how it monitors and manages the pool of
resources for creating tailored NSs. OOCRAN can automate NS reconfiguration,
but also facilitates user control. We demonstrate the dynamic deployment of
cellular NSs and discuss the challenges of dynamically creating and managing
tailored NSs on shared infrastructure.Comment: IEEE 5G World Forum 201
Illinois Precipitation Enhancement Program, Phase 1: Interim Report for 1 July 1972 - 31 July 1973
Division of Atmospheric Water Resources Management, Bureau of Reclamation, U.S. Department of Interior, Contract 14-06-D7197published or submitted for publicationis peer reviewedOpe
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