276 research outputs found
TK: The Twitter Top-K Keywords Benchmark
Information retrieval from textual data focuses on the construction of
vocabularies that contain weighted term tuples. Such vocabularies can then be
exploited by various text analysis algorithms to extract new knowledge, e.g.,
top-k keywords, top-k documents, etc. Top-k keywords are casually used for
various purposes, are often computed on-the-fly, and thus must be efficiently
computed. To compare competing weighting schemes and database implementations,
benchmarking is customary. To the best of our knowledge, no benchmark currently
addresses these problems. Hence, in this paper, we present a top-k keywords
benchmark, TK, which features a real tweet dataset and queries with
various complexities and selectivities. TK helps evaluate weighting
schemes and database implementations in terms of computing performance. To
illustrate TK's relevance and genericity, we successfully performed
tests on the TF-IDF and Okapi BM25 weighting schemes, on one hand, and on
different relational (Oracle, PostgreSQL) and document-oriented (MongoDB)
database implementations, on the other hand
Implementation of Multidimensional Databases with Document-Oriented NoSQL
International audienceNoSQL (Not Only SQL) systems are becoming popular due to known advantages such as horizontal scalability and elasticity. In this paper, we study the implementation of data warehouses with document-oriented NoSQL systems. We propose mapping rules that transform the multidimensional data model to logical document-oriented models. We consider three different logical models and we use them to instantiate data warehouses. We focus on data loading, model-to-model conversion and OLAP cuboid computation
ArDM: first results from underground commissioning
The Argon Dark Matter experiment is a ton-scale double phase argon Time
Projection Chamber designed for direct Dark Matter searches. It combines the
detection of scintillation light together with the ionisation charge in order
to discriminate the background (electron recoils) from the WIMP signals
(nuclear recoils). After a successful operation on surface at CERN, the
detector was recently installed in the underground Laboratorio Subterr\'aneo de
Canfranc, and the commissioning phase is ongoing. We describe the status of the
installation and present first results from data collected underground with the
detector filled with gas argon at room temperature.Comment: 6 pages, 3 figures, Light Detection In Noble Elements (LIDINE 2013
Status of the ArDM Experiment: First results from gaseous argon operation in deep underground environment
The Argon Dark Matter (ArDM-1t) experiment is a ton-scale liquid argon (LAr)
double-phase time projection chamber designed for direct Dark Matter searches.
Such a device allows to explore the low energy frontier in LAr. After
successful operation on surface at CERN, the detector has been deployed
underground and is presently commissioned at the Canfranc Underground
Laboratory (LSC). In this paper, we describe the status of the installation and
present first results on data collected in gas phase.Comment: 21 pages, 20 figure
The First 1 1/2 Years of TOTEM Roman Pot Operation at LHC
Since the LHC running season 2010, the TOTEM Roman Pots (RPs) are fully
operational and serve for collecting elastic and diffractive proton-proton
scattering data. Like for other moveable devices approaching the high intensity
LHC beams, a reliable and precise control of the RP position is critical to
machine protection. After a review of the RP movement control and position
interlock system, the crucial task of alignment will be discussed.Comment: 3 pages, 6 figures; 2nd International Particle Accelerator Conference
(IPAC 2011), San Sebastian, Spain; contribution MOPO01
Building an XML document warehouse
International audienceData Warehouses and OLAP (On Line Analytical Processing) technologies are dedicated to analyzing structured data issued from organizations' OLTP (On Line Transaction Processing) systems. Furthermore, in order to enhance their decision support systems, these organizations need to explore XML (eXtensible Markup Language) documents as an additional and important source of unstructured data. In this context, this paper addresses the warehousing of document-centric XML documents. More specifically, we propose a two-method approach to build Document Warehouse conceptual schemas. The first method is for the unification of XML document structures; it aims to elaborate a global and generic view for a set of XML documents belonging to the same domain. The second method is for designing multidimensional galaxy schemas for Document Warehouses
Les Houches "Physics at TeV Colliders 2003" Beyond the Standard Model Working Group: Summary Report
The work contained herein constitutes a report of the ``Beyond the Standard
Model'' working group for the Workshop "Physics at TeV Colliders", Les Houches,
France, 26 May--6 June, 2003. The research presented is original, and was
performed specifically for the workshop. Tools for calculations in the minimal
supersymmetric standard model are presented, including a comparison of the dark
matter relic density predicted by public codes. Reconstruction of
supersymmetric particle masses at the LHC and a future linear collider facility
is examined. Less orthodox supersymmetric signals such as non-pointing photons
and R-parity violating signals are studied. Features of extra dimensional
models are examined next, including measurement strategies for radions and
Higgs', as well as the virtual effects of Kaluza Klein modes of gluons. An LHC
search strategy for a heavy top found in many little Higgs model is presented
and finally, there is an update on LHC studies.Comment: 113 pages, ed B.C. Allanach, v5 has changes to part XV
The ArDM experiment
The aim of the ArDM project is the development and operation of a one ton
double-phase liquid argon detector for direct Dark Matter searches. The
detector measures both the scintillation light and the ionization charge from
ionizing radiation using two independent readout systems. This paper briefly
describes the detector concept and presents preliminary results from the ArDM
R&D program, including a 3 l prototype developed to test the charge readout
system.Comment: Proceedings of the Epiphany 2010 Conference, to be published in Acta
Physica Polonica
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