7,771 research outputs found
Representing and Utilizing DDI in Relational Databases
This document is primarily intended for implementers of DDI-based metadata stores who are considering different technical options for housing and managing their metadata. The Data Documentation Initiative (DDI) metadata specification is expressed in the form of XML schema. With version 3, the DDI specification has become quite complex, including 21 namespaces and 846 elements. Organizations employing DDI, or considering doing so, may want to 1. store and manage the metadata elements in relational databases, for reasons of integration with existing systems, familiarity with the concepts of relational databases (such as Structured Query Language), systems performance, and/or other reasons; 2. select only the subset of the available DDI metadata elements that is of utility to their work, and have the flexibility of capturing metadata they need that would not fit into the DDI model. This paper discusses advantages and disadvantages of the relational database approach to managing DDI. It also describes methods for modeling DDI in relational databases and for formally defining subsets of DDI to employ in this environment.
The VizieR database of Astronomical Catalogues
VizieR is a database grouping in an homogeneous way thousands of astronomical
catalogues gathered since decades by the Centre de Donnees de Strasbourg (CDS)
and participating institutes. The history and current status of this large
collection is briefly presented, and the way these catalogues are being
standardized to fit in the VizieR system is described. The architecture of the
database is then presented, with emphasis on the management of links and of
accesses to very large catalogues. Several query interfaces are currently
available, making use of the ASU protocol, for browsing purposes or for use by
other data processing systems such as visualisation tools.Comment: 10 pages, 2 Postscript figures; to be published in A&A
Mapping Large Scale Research Metadata to Linked Data: A Performance Comparison of HBase, CSV and XML
OpenAIRE, the Open Access Infrastructure for Research in Europe, comprises a
database of all EC FP7 and H2020 funded research projects, including metadata
of their results (publications and datasets). These data are stored in an HBase
NoSQL database, post-processed, and exposed as HTML for human consumption, and
as XML through a web service interface. As an intermediate format to facilitate
statistical computations, CSV is generated internally. To interlink the
OpenAIRE data with related data on the Web, we aim at exporting them as Linked
Open Data (LOD). The LOD export is required to integrate into the overall data
processing workflow, where derived data are regenerated from the base data
every day. We thus faced the challenge of identifying the best-performing
conversion approach.We evaluated the performances of creating LOD by a
MapReduce job on top of HBase, by mapping the intermediate CSV files, and by
mapping the XML output.Comment: Accepted in 0th Metadata and Semantics Research Conferenc
An overview of decision table literature.
The present report contains an overview of the literature on decision tables since its origin. The goal is to analyze the dissemination of decision tables in different areas of knowledge, countries and languages, especially showing these that present the most interest on decision table use. In the first part a description of the scope of the overview is given. Next, the classification results by topic are explained. An abstract and some keywords are included for each reference, normally provided by the authors. In some cases own comments are added. The purpose of these comments is to show where, how and why decision tables are used. Other examined topics are the theoretical or practical feature of each document, as well as its origin country and language. Finally, the main body of the paper consists of the ordered list of publications with abstract, classification and comments.
OEXP Analysis Tools Workshop
This publication summarizes the software needs and available analysis tools presented at the OEXP Analysis Tools Workshop held at the NASA Langley Research Center, Hampton, Virginia on June 21 to 22, 1988. The objective of the workshop was to identify available spacecraft system (and subsystem) analysis and engineering design tools, and mission planning and analysis software that could be used for various NASA Office of Exploration (code Z) studies, specifically lunar and Mars missions
IVOA Recommendation: VOTable Format Definition Version 1.3
This document describes the structures making up the VOTable standard. The
main part of this document describes the adopted part of the VOTable standard;
it is followed by appendices presenting extensions which have been proposed
and/or discussed, but which are not part of the standard
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