8,139 research outputs found
The ATLAS EventIndex: a BigData catalogue for all ATLAS experiment events
The ATLAS EventIndex system comprises the catalogue of all events collected,
processed or generated by the ATLAS experiment at the CERN LHC accelerator, and
all associated software tools to collect, store and query this information.
ATLAS records several billion particle interactions every year of operation,
processes them for analysis and generates even larger simulated data samples; a
global catalogue is needed to keep track of the location of each event record
and be able to search and retrieve specific events for in-depth investigations.
Each EventIndex record includes summary information on the event itself and the
pointers to the files containing the full event. Most components of the
EventIndex system are implemented using BigData open-source tools. This paper
describes the architectural choices and their evolution in time, as well as the
past, current and foreseen future implementations of all EventIndex components.Comment: 21 page
The IceCube Neutrino Observatory: Instrumentation and Online Systems
The IceCube Neutrino Observatory is a cubic-kilometer-scale high-energy
neutrino detector built into the ice at the South Pole. Construction of
IceCube, the largest neutrino detector built to date, was completed in 2011 and
enabled the discovery of high-energy astrophysical neutrinos. We describe here
the design, production, and calibration of the IceCube digital optical module
(DOM), the cable systems, computing hardware, and our methodology for drilling
and deployment. We also describe the online triggering and data filtering
systems that select candidate neutrino and cosmic ray events for analysis. Due
to a rigorous pre-deployment protocol, 98.4% of the DOMs in the deep ice are
operating and collecting data. IceCube routinely achieves a detector uptime of
99% by emphasizing software stability and monitoring. Detector operations have
been stable since construction was completed, and the detector is expected to
operate at least until the end of the next decade.Comment: 83 pages, 50 figures; updated with minor changes from journal review
and proofin
A Survey on Virtualization of Wireless Sensor Networks
Wireless Sensor Networks (WSNs) are gaining tremendous importance thanks to their broad range of commercial applications such as in smart home automation, health-care and industrial automation. In these applications multi-vendor and heterogeneous sensor nodes are deployed. Due to strict administrative control over the specific WSN domains, communication barriers, conflicting goals and the economic interests of different WSN sensor node vendors, it is difficult to introduce a large scale federated WSN. By allowing heterogeneous sensor nodes in WSNs to coexist on a shared physical sensor substrate, virtualization in sensor network may provide flexibility, cost effective solutions, promote diversity, ensure security and increase manageability. This paper surveys the novel approach of using the large scale federated WSN resources in a sensor virtualization environment. Our focus in this paper is to introduce a few design goals, the challenges and opportunities of research in the field of sensor network virtualization as well as to illustrate a current status of research in this field. This paper also presents a wide array of state-of-the art projects related to sensor network virtualization
- …