Paper 72 (Research track)

Processing incoherent open government data- A case-study about Romanian public contracts funded by European Union

Author(s): Bogdan Ghita, Octavian Rinciog, Vlad Posea

Abstract: Lately, many governments have adopted policies and mechanisms for making open data available to citizens, in order to increase the transparency of state administration and institutions. The usage of these data is hampered by the incorrect, incomplete and incoherent nature of the information.

The purpose of this paper is to summarize the general steps that are needed in order to transform raw open data that contain errors to consistent data. These steps are used to correct the open data published by the Romanian government regarding public contracts funded by European Union, supporting entities interested in using these data.

Keywords: Open Data; semantic web; error correction

Paper 5 (Research track)

Price Sharing for Streaming Data- A Novel Approach for Funding RDF Stream Processing

Author(s): Tobias Grubenmann, Daniele Dell’Aglio, Abraham Bernstein, Dmitry Moor, Sven Seuken

Abstract: RDF Stream Processing (RSP) has proposed solutions to continuously query streams of RDF data. As a result, it is today possible to create complex networks of RSP engines to process streaming data in a distributed and continuous fashion. Indeed, some approaches even allow to distribute the computation across the web. But both producing high-quality data and providing compute power to process it costs money.

The usual approach to financing data on the Web of Data today is that either some sponsor subsidizes it or the consumers are charged. In the stream setting consumers could exploit synergies and, theoretically, share the access and processing fees, should their needs overlap. But what should be the monetary contribution of each consumer when they have varying valuations of the differing outcomes?

In this article, we propose a model for price sharing in the RDF Stream Processing setting. Based on the consumers’ outcome valuations and the pricing of the raw data streams, our algorithm computes utility-maximizing prices different consumers should contribute whilst ensuring that all the participants have no incentive of manipulating the system by providing misinformation about their value, budget, or requested data stream. We show that our algorithm is able to calculate such prices in a reasonable amount of time for up to one thousand simultaneous queries.

Keywords: RDF Streaming Processing; Price Sharing; Equal-Need Sharing

Paper 227 (Research track)

Dynamic Tailoring of RETE Networks in Incremental Scenarios

Author(s): William Van Woensel, Syed Sibte Raza Abidi

Abstract: Decision support systems, with production rule systems at their core, have an opportunity to leverage the embedded semantics of semantic, ontology-based data to improve decision support accuracy. Advances in mobile hardware are enabling these rule-based systems to be deployed on mobile, ubiquitous platforms. By deploying reasoning processes locally, time-sensitive tasks are no longer influenced by network conditions, less bandwidth is wasted, and less re-mote (costly) resources are needed. Despite hardware advances however, recent benchmarks found that, when directly re-using existing (PC- or server-based) technologies, the scalability of reasoning on mobile platforms is greatly limited. To realize efficient semantic reasoning on resource-constrained platforms, utilizing rule-based axiomatizations of ontology semantics (e.g., OWL 2 RL), which are known to trade expressivity for scalability, is a useful first step. Furthermore, the highly dynamic nature of mobile and ubiquitous settings, where data is typically encountered on-the-fly, requires special consideration. We pro-pose a tailored version of the RETE algorithm, the mainstay algorithm for production rule systems. This algorithm dynamically adapts RETE networks based on the evolving relevance of rules, with the goal of reducing their resource consumption. We perform an evaluation of semantic reasoning using our custom algorithm and an OWL2 RL ruleset, both on the PC and mobile platform.

Keywords: RETE; OWL2 RL; rule-based reasoning; OWL reasoning; reasoning optimization

Paper 226 (Resources track)

Build a corpus of scientific articles with semantic representation

Author(s): Jean-Claude Moissinac

Abstract: As part of the SemBib project, we undertook a semantic representation of the scientific production of Telecom Paristech. Beyond the internal objectives, this enriched corpus is a source of experimentation and a teaching resource. This work is based on the use of text mining methods to build graphs of knowledge, and then on the production of analyzes from these graphs. The main proposal is the disjoint graph production methodology, with clearly identified roles, to allow for differentiated uses, and in particular the comparison between graph production and exploitation methods. This article is above all a methodological proposition for the organization of semantic representation of publications, relying on methods of text mining. The proposed method facilitates progressive enrichment approaches to representations with evaluation possibilities at each step.

Keywords: semantic publishing; publication; Linked Data; SPARQL