Alsubaiee S.,University of California at Irvine |
Behm A.,Cloudera |
Borkar V.,University of California at Irvine |
Heilbron Z.,University of California at Irvine |
And 4 more authors.
Proceedings of the VLDB Endowment | Year: 2014
Social networks, online communities, mobile devices, and instant messaging applications generate complex, unstructured data at a high rate, resulting in large volumes of data. This poses new challenges for data management systems that aim to ingest, store, index, and analyze such data efficiently. In response, we released the first public version of AsterixDB, an open-source Big Data Management System (BDMS), in June of 2013. This paper describes the storage management layer of AsterixDB, providing a detailed description of its ingestion-oriented approach to local storage and a set of initial measurements of its ingestion-related performance characteristics. In order to support high frequency insertions, AsterixDB has wholly adopted Log-Structured Merge-trees as the storage technology for all of its index structures. We describe how the AsterixDB software framework enables "LSM-ification" (conversion from an in-place update, disk-based data structure to a deferredupdate, append-only data structure) of any kind of index structure that supports certain primitive operations, enabling the index to ingest data efficiently. We also describe how AsterixDB ensures the ACID properties for operations involving multiple heterogeneous LSM-based indexes. Lastly, we highlight the challenges related to managing the resources of a system when many LSM indexes are used concurrently and present AsterixDB's initial solution. © 2014 VLDB Endowment.
Waitelonis J.,Hasso Plattner Institute Potsdam |
Sack H.,Hasso Plattner Institute Potsdam
Multimedia Tools and Applications | Year: 2012
Keyword-based search in general is particularly applicable if the searcher really knows what she is looking for and how to find it, i.e. to know the appropriate keywords to obtain the desired results. But in many cases either the objectives of the searcher are intrinsically fuzzy or she is not aware of the appropriate keywords. One way to solve this problem is to navigate and explore the search space along guided routes. In this paper we show, how Linked Open Data can be adopted to facilitate an exploratory semantic search for video data. We present a prototype implementation of exploratory video search and show how traditional keyword-based search can be augmented by the use of Linked Open Data. © Springer Science+Business Media, LLC 2011.
Wenzel M.,Hasso Plattner Institute Potsdam |
Meinel C.,Hasso Plattner Institute Potsdam
2015 International Conference on Collaboration Technologies and Systems, CTS 2015 | Year: 2015
Gericke L.,Hasso Plattner Institute Potsdam |
Meinel C.,Hasso Plattner Institute Potsdam
Proceedings of the 2012 IEEE 13th International Conference on Information Reuse and Integration, IRI 2012 | Year: 2012
Asynchronous work settings demand for certain hand-over processes - often performed by documentation of the work. This task is challenging especially for creative work, because finding the right form of documentation - including decisions that have been made and explanations how people came to solutions - is non-trivial. Capturing the whole process and replay it afterwards to distributed team members could solve those problems, but is hardly realizable in terms of time consumption. Our approach uses the complete capturing of a session - exemplary implemented using a digital whiteboard system - in order to find out phases of work. This enables us to point out relations between different phases, which can tell us what part was more important than another. We found out that the definition of time slices consisting of certain parameters describing the process can be aggregated into segments. Those segments are classified using an SVM approach, which turns out to give promising results. The overall contribution is an approach, which can be generalized for a variety of captured parameters to allow a precise classification of segments related to the respective overall task. © 2012 IEEE.
Trumper J.,Hasso Plattner Institute Potsdam |
Telea A.,University of Groningen |
Dollner J.,Hasso Plattner Institute Potsdam
Theory and Practice of Computer Graphics 2012, TPCG 2012 - Eurographics UK Chapter Proceedings | Year: 2012
Visualization of data on structure and related temporal activity supports the analysis of correlations between the two types of data. This is typically done by linked views. This has shortcomings with respect to efficient space usage and makes mapping the effect of user input into one view into the other view difficult. We propose here a novel, space-efficient technique that 'fuses' the two information spaces - structure and activity - in one view. We base our technique on the idea that user interaction should be simple, yet easy to understand and follow. We apply our technique, implemented in a prototype tool, for the understanding of software engineering datasets, namely static structure and execution traces of the Chromium web browser. © The Eurographics Association 2012.