Browsing Articles  Computer Science by Author "Gamper J"
Now showing items 112 of 12

The address connector: Noninvasive synchronization of hierarchical data sources
Augsten N; Böhlen MH; Gamper J (SPRINGER LONDON LTD, 2013)Different databases often store information about the same or related objects in the real world. To enable collaboration between these databases, data items that refer to the same object must be identified. Residential ... 
DigitHist: a HistogramBased Data Summary with Tight Error Bounds
Shekelyan M; Dignös A; Gamper J (2017)We propose DigitHist, a histogram summary for selectivity estimation on multidimensional data with tight error bounds. By combining multidimensional and onedimensional histograms along regular grids of different ... 
Extending the Kernel of a Relational DBMS with Comprehensive Support for Sequenced Temporal Queries
Dignös A; Böhlen MH; Gamper J; Jensen CS (ACM, 2016)Many databases contain temporal, or timereferenced, data and use intervals to capture the temporal aspect. While SQLbased database management systems (DBMSs) are capable of supporting the management of interval data, the ... 
Improved lower bounds for graph edit distance
Blumenthal DB; Gamper J (2018)The problem of deriving lower and upper bounds for the edit distance between undirected, labeled graphs has recently received increasing attention. However, only one algorithm has been proposed that allegedly computes not ... 
Interactive and spaceefficient multidimensional time series subsequence matching
Piatov D; Helmer S; Dignös A; Gamper J (2019)We develop a highly efficient access method, called DeltaTopIndex, to answer topkk" role="presentation"> subsequence matching queries over a multidimensional time series data set. Compared to a naïve implementation, ... 
On the exact computation of the graph edit distance
Blumenthal DB; Gamper J (2018)The graph edit distance is a widely used distance measure for labelled graph. However, the standard approach for its exact computation, suffers from huge runtime and memory requirements. Recently, three better performing ... 
osmPti2mmds  Erstellung von multimodalen Datensets aus OpenStreetMap und ÖPNVInformationen
Krismer N; Silbernagl D; Gamper J; Specht G (2016)In dieser Arbeit wird ein Werkzeug vorgestellt, mit dem Datenbankelemente des OpenStreetMapProjekts in Java JTSObjekte konvertiert werden. Hauptaugenmerk liegt hierbei auf (Multi)Polygonrelationen, da diese nicht ... 
Parsimonious temporal aggregation
Gordevicius J; Gamper J; Böhlen MH (2012)Temporal aggregation is an important operation in temporal databases, and different variants thereof have been proposed. In this paper, we introduce a novel temporal aggregation operator, termed parsimonious temporal ... 
A scalable dynamic programming scheme for the computation of optimal ksegments for ordered data
Mahlknecht G; Dignös A; Gamper J (2017)The optimal kksegments of an ordered dataset of size nn consists of kk tuples that are obtained by merging consecutive tuples such that a given error metric is minimized. The problem is general and has been studied in ... 
Sequenced spatiotemporal aggregation for coarse query granularities
Timko I; Böhlen MH; Gamper J (2011)Sequenced spatiotemporal aggregation (SSTA) is an important query for many applications of spatiotemporal databases, such as traffic analysis. Conceptually, an SSTA query returns one aggregate value for each individual ... 
Snapshot Semantics for Temporal Multiset Relations
Dignös A; Glavic B; Niu X; Böhlen M; Gamper J (2019)Snapshot semantics is widely used for evaluating queries over temporal data: temporal relations are seen as sequences of snapshot relations, and queries are evaluated at each snapshot. In this work, we demonstrate that ... 
Sparse prefix sums: Constanttime range sum queries over sparse multidimensional data cubes
Shekelyan M; Dignös A; Gamper J (2019)Prefix sums are a powerful technique to answer rangesum queries over multidimensional arrays in O(1) time by looking up a constant number of values in an array of size O(N), where N is the number of cells in the ...