Towards a Foundation of Data Currency

Author(s):  
Jef Wijsen
Keyword(s):  
Author(s):  
Xuliang Duan ◽  
Bing Guo ◽  
Yan Shen ◽  
Yuncheng Shen ◽  
Xiangqian Dong ◽  
...  
Keyword(s):  

2001 ◽  
Vol 10 (03) ◽  
pp. 299-326 ◽  
Author(s):  
DIMITRI THEODORATOS ◽  
MOKRANE BOUZEGHOUB

A Data Warehouse (DW) is a large collection of data integrated from multiple distributed autonomous databases and other information sources. A DW can be seen as a set of materialized views defined over the remote source data. Until now research work on DW design is restricted to quantitatively selecting view sets for materialization. However, quality issues in the DW design are neglected. In this paper we suggest a novel statement of the DW design problem that takes into account quality factors. We design a DW system architecture that supports performance and data consistency quality goals. In this framework we present a high level approach that allows to check whether a view selection guaranteeing a data completeness quality goal also satisfies a data currency quality goal. This approach is based on an AND/OR dag representation for multiple queries and views. It also allows determining the minimal change propagation frequencies that satisfy the data currency quality goal along with the optimal query evaluation and change propagation plans. Our results can be directly used for a quality driven design of a DW.


Author(s):  
S. Koswatte ◽  
K. Mcdougall ◽  
X. Liu

Crowdsourced Data (CSD) has recently received increased attention in many application areas including disaster management. Convenience of production and use, data currency and abundancy are some of the key reasons for attracting this high interest. Conversely, quality issues like incompleteness, credibility and relevancy prevent the direct use of such data in important applications like disaster management. Moreover, location information availability of CSD is problematic as it remains very low in many crowd sourced platforms such as Twitter. Also, this recorded location is mostly related to the mobile device or user location and often does not represent the event location. In CSD, event location is discussed descriptively in the comments in addition to the recorded location (which is generated by means of mobile device's GPS or mobile communication network). This study attempts to semantically extract the CSD location information with the help of an ontological Gazetteer and other available resources. 2011 Queensland flood tweets and Ushahidi Crowd Map data were semantically analysed to extract the location information with the support of Queensland Gazetteer which is converted to an ontological gazetteer and a global gazetteer. Some preliminary results show that the use of ontologies and semantics can improve the accuracy of place name identification of CSD and the process of location information extraction.


2014 ◽  
Vol 5 (1-2) ◽  
pp. 1-37 ◽  
Author(s):  
Wenfei Fan ◽  
Floris Geerts ◽  
Nan Tang ◽  
Wenyuan Yu

Database ◽  
2012 ◽  
Vol 2012 ◽  
Author(s):  
Allan Peter Davis ◽  
Robin J. Johnson ◽  
Kelley Lennon-Hopkins ◽  
Daniela Sciaky ◽  
Michael C. Rosenstein ◽  
...  

Author(s):  
Sergio Pio Alvarez ◽  
Adriana Marotta ◽  
Libertad Tansini
Keyword(s):  

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