Florian Stegmaier

Combined semantic and similarity search in medical image databases

The current diagnostic process at hospitals is mainly based on reviewing and comparing images coming from multiple time points and modalities in order to monitor disease progression over a period of time. However, for ambiguous cases the radiologist deeply relies on reference literature or second opinion. Although there is a vast amount of acquired images stored in PACS systems which could be reused for decision support, these data sets suffer from weak search capabilities. Thus, we present a search methodology which enables the physician to fulfill intelligent search scenarios on medical image databases combining ontology-based semantic and appearance-based similarity search. It enabled the elimination of 12% of the top ten hits which would arise without taking the semantic context into account.

AIR: Architecture for interoperable retrieval on distributed and heterogeneous multimedia repositories

Nowadays multimedia data is produced and consumed at an ever increasing rate. Similarly to this trend, diverse storage approaches for multimedia data have been introduced. These observations lead to the fact that distributed and heterogeneous multimedia repositories exist whereas an unified and easy access to the stored multimedia data is not given. This paper presents an architecture, named AIR, that offers the aformentioned retrieval possibilites. To ensure interoperability, AIR makes use of recently issued standards, namely the MPEG Query Format (MPQF) (multimedia query language) and the JPSearch transformation rules (metadata interoperability).

Balloon Fusion: SPARQL rewriting based on unified co-reference information

While Linked Open Data showed enormous increase in volume, yet there is no single point of access for querying the over 200 SPARQL repositories. In this paper we present Balloon Fusion, a SPARQL 1.1 rewriting and query federation service build on crawling and consolidating co-reference relationships in over 100 reachable Linked Data SPARQL Endpoints. The results of this process are 17.6M co-reference statements that have been clustered to 8.4M distinct semantic entities and are now accessible as download for further analysis. The proposed SPARQL rewriting performs a substitution of all URI occurrences with their synonyms combined with an automatic endpoint selection based on URI origin for a comprehensive query federation. While we show the technical feasibility, we also critically reflect the current status of the Linked Open Data cloud: although it is huge in size, access via SPARQL Endpoints is complicated in most cases due to missing quality of service.

Landmark-assisted location and tracking in outdoor mobile network

Modern mobile devices integrating sensors, like accelerometers and cameras, are paving the way to the definition of high-quality and accurate geolocation solutions based on the informations acquired by these sensors, and data collected and managed by GSM/3G networks. In this paper, we present a technique that provides geolocation and mobility prediction of mobile devices, mixing the location information acquired with the GSM/3G infrastructure and the results of a landmark matching achieved thanks to the camera integrated on the mobile devices. Our geolocation approach is based on an advanced Time-Forwarding algorithm and on database correlation technique over Received Signal Strength Indication (RSSI) data, and integrates information produced by a landmark recognition infrastructure, to enhance algorithm performances in those areas with poor signal and low accurate geolocation. Performances of the algorithm are evaluated on real data from a complex urban environment.

Standardized interoperable image retrieval

Digital still images are generated, distributed and stored worldwide at an ever increasing rate. Yet, the large number of available metadata description formats prevents consistent and efficient access to image repositories. Standardized solutions for unifying the access and the retrieval of image repositories are therefore strongly needed. The ISO/IEC SC29 WG1 (more commonly known as JPEG) established the JPSearch project, which aims to standardize interfaces of an abstract image retrieval framework. In this context, the paper introduces our contribution consisting of a reference metadata model, which in combination with the JPEG query format improves interoperable image retrieval for users. Second, a transformation rule declaration language for query reformulation is presented, which contributes to interoperability at the repository side.

Unleashing Semantics of Research Data

Research depends to a large degree on the availability and quality of primary research data, i.e., data generated through experiments and evaluations. While the Web in general and Linked Data in particular provide a platform and the necessary technologies for sharing, managing and utilizing research data, an ecosystem supporting those tasks is still missing. The vision of the CODE project is the establishment of a sophisticated ecosystem for Linked Data. Here, the extraction of knowledge encapsulated in scientific research paper along with its public release as Linked Data serves as the major use case. Further, Visual Analytics approaches empower end users to analyse, integrate and organize data. During these tasks, specific Big Data issues are present.

JPEG's JPSearch Standard: Harmonizing Image Management and Search

Triggered by the rise of social networks, community-based image sharing platforms are emerging at an increasing rate. Currently, almost every repository offers a different interaction interface and metadata description format. Unfortunately, this prevents unified and efficient access to these repositories. Consequently, data exchange between systems is often cumbersome. In this context, ISO/IEC JTC1 SC29 WG1 (more commonly known as JPEG) initiated the JPSearch framework standardization, which aims to foster the interaction with and among image repositories. The standard focuses on three main cornerstones supporting repository synchronization, search and access, and image collection creation and maintenance. This article discusses the main concepts, parts, and achievements of the JPSearch framework and demonstrates its use through a set of substantial case studies.

Crowdsourcing Fact Extraction from Scientific Literature

Scientific publications constitute an extremely valuable body of knowledge and can be seen as the roots of our civilisation. However, with the exponential growth of written publications, comparing facts and findings between different research groups and communities becomes nearly impossible. In this paper, we present a conceptual approach and a first implementation for creating an open knowledge base of scientific knowledge mined from research publications. This requires to extract facts - mostly empirical observations - from unstructured texts (mainly PDF’s). Due to the importance of extracting facts with high-accuracy and the impreciseness of automatic methods, human quality control is of utmost importance. In order to establish such quality control mechanisms, we rely on intelligent visual interfaces and on establishing a toolset for crowdsourcing fact extraction, text mining and data integration tasks.

Balloon Synopsis: A Modern Node-Centric RDF Viewer and Browser for the Web

Nowadays, the RDF data model is a crucial part of the Semantic Web. Especially web developers favour RDF serialization formats like RDFa and JSON-LD. However, the visualization of large portions of RDF data in an appealing way is still a cumbersome task. RDF visualizers in general are not targeting the Web as usage scenario or simply display the complex RDF graph directly rather than applying a human friendly facade. Balloon Synopsis tries to overcome these issues by providing an easy-to-use RDF visualizer based on HTML and JavaScript. For an ease integration, it is implemented as jQuery-plugin offering a node-centric RDF viewer and browser with automatic Linked Data enhancement in a modern tile design.

SPARQL-MM - Extending SPARQL to Media Fragments

Interconnecting machine readable data with multimedia assets and fragments has recently become a common practice. But specific retrieval techniques for the so called Semantic Multimedia data are still lacking. On our poster we present SPARQL-MM, a function set that extends SPARQL to Media Fragment facilities by introducing spatio-temporal filter and aggregation functions.