Decentralized Control and Adaptation in Distributed Applications via Web and Semantic Web Technologies

The presented work provides an approach and an implementation for enabling decentralized control in distributed applications composed of heterogeneous components by benefiting from the interoperability provided by the Web stack and relying on semantic technologies for enabling data integration. In particular, the concept of Smart Components enables adaptability at runtime through an adaptation layer and is complemented by a reference architecture as well as a prototypical implementation

Building REST APIs for the Robot Operating System - Mapping Concepts and Interaction

The vision of the Web of Things (WoT) aims to leverage Web standards in order to interconnect all types of embedded devices and real world objects, and thus to make them a part of the WWW. Therefore, WoT aims to build a future Web of devices that is truly open, flexible, and scalable. We aim to contribute towards achieving this goal by relying on existing and well-known Web standards used in the programmable Web (e.g., URI, and HTTP) and the semantic Web (e.g., RDF), in order to enable the Web integration of Robot Operating System (ROS) devices. In particular, we motivate the problem of integrating ROS devices in Web environments, elaborate on the integration potential, and describe specific application examples. We provide a mapping between ROS and REST concepts and interaction primitives. In addition, we show how REST is capable to enhance a mapping of the ROS architecture in terms of complex resources and hypermedia. The contributions described in this paper pave the way towards realising a WoT, where ROS devices can be easily accessed and directly integrated by using standard Web technologies, without additional custom implementation effort or having to add intermediate communication layers

EUD-MARS: End-User Development of Model-Driven Adaptive Robotics Software Systems

Empowering end-users to program robots is becoming more significant. Introducing software engineering principles into end-user programming could improve the quality of the developed software applications. For example, model-driven development improves technology independence and adaptive systems act upon changes in their context of use. However, end-users need to apply such principles in a non-daunting manner and without incurring a steep learning curve. This paper presents EUD-MARS that aims to provide end-users with a simple approach for developing model-driven adaptive robotics software. End-users include people like hobbyists and students who are not professional programmers but are interested in programming robots. EUD-MARS supports robots like hobby drones and educational humanoids that are available for end-users. It offers a tool for software developers and another one for end-users. We evaluated EUD-MARS from three perspectives. First, we used EUD-MARS to program different types of robots and assessed its visual programming language against existing design principles. Second, we asked software developers to use EUD-MARS to configure robots and obtained their feedback on strengths and points for improvement. Third, we observed how end-users explain and develop EUD-MARS programs, and obtained their feedback mainly on understandability, ease of programming, and desirability. These evaluations yielded positive indications of EUD-MARS

grlc Makes GitHub Taste Like Linked Data APIs

Building Web APIs on top of SPARQL endpoints is becoming a common practice to enable universal access to the integration favorable dataspace of Linked Data. However, the Linked Data community cannot expect users to learn SPARQL to query this dataspace, and Web APIs are the most common way of enabling programmatic access to data on the Web. However, the implementation of Web APIs around Linked Data is often a tedious and repetitive process. Recent work speeds up this Linked Data API construction by wrapping it around SPARQL queries, which carry out the API functionality under the hood. Inspired by this, in this paper we present grlc, a lightweight server that translates SPARQL queries curated in GitHub repositories to Linked Data APIs on the fly

NoSQL Databases for RDF: An Empirical Evaluation

Processing large volumes of RDF data requires sophisticated tools. In recent years, much effort was spent on optimizing native RDF stores and on repurposing relational query engines for large-scale RDF processing. Concurrently, a number of new data management systems-regrouped under the NoSQL (for "not only SQL") umbrella-rapidly rose to prominence and represent today a popular alternative to classical databases. Though NoSQL systems are increasingly used to manage RDF data, it is still difficult to grasp their key advantages and drawbacks in this context. This work is, to the best of our knowledge, the first systematic attempt at characterizing and comparing NoSQL stores for RDF processing. In the following, we describe four different NoSQL stores and compare their key characteristics when running standard RDF benchmarks on a popular cloud infrastructure using both single-machine and distributed deployments. © 2013 Springer-Verlag

ARVIDA-Referenzarchitektur: Ressourcen-orientierte Architekturen für die Anwendungsentwicklung virtueller Techniken

The ARVIDA reference architecture is a central result of the ARVDIA project. With the help of well-established web technologies and concepts the reference architecture enables heterogeneous VT systems to become platform independent applications. The reference architecture uses and adopts the principle of RESTful web services and the associated Linked-Data concepts to build interoperable, extensible and modular VT applications. This chapter describes the basic principles and the specific extensions in detail