Now showing items 1-20 of 46

    • 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 ...
    • Alternative Routing: k Shortest Paths with Limited Overlap 

      Chondrogiannis T; Bouros P; Gamper J; Leser U (ACM, 2015)
      Shortest path computation is a fundamental problem in road net- works with application in various domains in research and industry. However, returning only the shortest path is often not satisfying; users are also interested ...
    • Computing Isochrones in Multimodal Spatial Networks using Tile Regions 

      Krismer N; Silbernagl D; Specht G; Gamper J (ACM, 2017)
      This paper describes a new method to compute isochrones in multimodal spatial networks, which aims at finding a good trade-off between memory usage and runtime. In the past, approaches based on Dijkstra's algorithm have ...
    • Continuous Imputation of Missing Values in Streams of Pattern-Determining Time Series 

      Wellenzohn K; Böhlen M; Dignös A; Gamper J; Mitterer H (OpenProceedings.org, 2017)
      Time series data is ubiquitous but often incomplete, e.g., due to sensor failures and transmission errors. Since many applications require complete data, missing values must be imputed before further data processing is ...
    • Correcting and Speeding-Up Bounds for Non-Uniform Graph Edit Distance 

      Blumenthal DB; Gamper J (IEEE Computer Society, 2017)
      The problem of deriving lower and upper bounds for the edit distance between labelled undirected graphs has recently received increasing attention. However, only one algorithm has been proposed that allegedly computes not ...
    • Database Technology for Processing Temporal Data (Invited Paper) 

      Böhlen M H; Dignös A; Gamper J; Jensen C S (Schloss Dagstuhl - Leibniz-Zentrum fuer Informatik, 2018)
      Despite the ubiquity of temporal data and considerable research on processing such data, database systems largely remain designed for processing the current state of some modeled reality. More recently, we have seen an ...
    • DigitHist: a Histogram-Based Data Summary with Tight Error Bounds 

      Shekelyan M; Dignös A; Gamper J (2017)
      We propose DigitHist, a histogram summary for selectivity estimation on multi-dimensional data with tight error bounds. By combining multi-dimensional and one-dimensional histograms along regular grids of different ...
    • Diversifying search results of controversial queries 

      Kacimi M; Gamper J (ACM, 2011)
      Diversifying search results of queries seeking for different view points about controversial topics is key to improving satisfaction of users. The challenge for finding different opinions is how to maximize the number of ...
    • E-Government: Towards Electronic Democracy: International Conference, TCGOV 2005, Bolzano, Italy, March 2-4, 2005, Proceedings 

      Boehlen M; Gamper J; Polasek W; Wimmer M (Springer, 2005)
      The TCGOV 2005 international conference on e-government was held at the Free University of Bozen-Bolzano during March 2–4, 2005. The conference was initiated by the working group “Towards Electronic Democracy” (TED) of the ...
    • Efficient Computation of Parsimonious Temporal Aggregation 

      Mahlknecht G; Dignös A; Gamper J (Springer, 2015)
      Parsimonious temporal aggregation (PTA) has been introduced to overcome limitations of previous temporal aggregation operators, namely to provide a concise yet data sensitive summary of temporal data. The basic idea of PTA ...
    • Efficient Itinerary Planning with Category Constraints 

      Bolzoni P; Helmer S; Wellenzohn K; Gamper J; Andritsos P (Association for Computing Machinery, 2014)
      We propose a more realistic approach to trip planning for tourist applications by adding category information to points of interest (POIs). This makes it easier for tourists to formulate their preferences by stating ...
    • Exact and Approximate Algorithms for Finding k-Shortest Paths with Limited Overlap 

      Chondrogiannis T; Bouros P; Gamper J; Leser U (OpenProceedings.org, 2017)
      Shortest path computation is a fundamental problem in road net- works with various applications in research and industry. However, returning only the shortest path is often not satisfying. Users might also be interested ...
    • Exact Computation of Graph Edit Distance for Uniform and Non-uniform Metric Edit Costs 

      Blumenthal DB; Gamper J (Springer, 2017)
      The graph edit distance is a well-established and widely used distance measure for labelled, undirected graphs. However, since its exact computation is NP -hard, research has mainly focused on devising approximative ...
    • Exploring Graph Partitioning for Shortest Path Queries on Road Networks 

      Chondrogiannis T; Gamper J (Gesellschaft für Informatik e.V., 2014)
      Computing the shortest path between two locations in a road network is an important  problem that has found numerous applications. The classic solution for the problem is Dijkstra’s algorithm. Although simple and elegant, ...
    • 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 time-referenced, data and use intervals to capture the temporal aspect. While SQL-based database management systems (DBMSs) are capable of supporting the management of interval data, the ...
    • GEDLIB: A C++ Library for Graph Edit Distance Computation 

      Blumenthal DB; Bougleux S; Gamper J; Brun L (Springer, 2019)
      The graph edit distance (GED) is a flexible graph dissimilarity measure widely used within the structural pattern recognition field. In this paper, we present GEDLIB, a C++ library for exactly or approximately computing ...
    • 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 ...
    • Incremental Calculation of Isochrones Regarding Duration 

      Krismer N; Specht G; Gamper J (Gesellschaft für Informatik, 2014)
      An isochrone in a spatial network is the minimal, possibly disconnected subgraph that covers all locations from where a query point is reachable within a given time span and by a given arrival time [5]. A novel approach ...
    • An Incrementally Maintainable Index for Approximate Lookups in Hierarchical Data 

      Augsten N; Böhlen M; Gamper J (ACM, 2006)
      Several recent papers argue for approximate lookups in hierarchical data and propose index structures that support approximate searches in large sets of hierarchical data. These index structures must be updated if the ...
    • Interactive and space-efficient multi-dimensional time series subsequence matching 

      Piatov D; Helmer S; Dignös A; Gamper J (2019)
      We develop a highly efficient access method, called Delta-Top-Index, to answer top-kk" role="presentation"> subsequence matching queries over a multi-dimensional time series data set. Compared to a naïve implementation, ...