Towards MANET-based Recommender Systems for Open Facilities

Nowadays, most recommender systems are based on a centralized architecture, which can cause crucial issues in terms of trust, privacy, dependability, and costs. In this paper, we propose a decentralized and distributed MANET-based (Mobile Ad-hoc NETwork) recommender system for open facilities. The system is based on mobile devices that collect sensor data about users locations to derive implicit ratings that are used for collaborative filtering recommendations. The mechanisms of deriving ratings and propagating them in a MANET network are discussed in detail. Finally, extensive experiments demonstrate the suitability of the approach in terms of different performance metrics. © 2021, The Author(s)

I am all EARS: Using open data and knowledge graph embeddings for music recommendations

Music streaming platforms offer music listeners an overwhelming choice of music. Therefore, users of streaming platforms need the support of music recommendation systems to find music that suits their personal taste. Currently, a new class of recommender systems based on knowledge graph embeddings promises to improve the quality of recommendations, in particular to provide diverse and novel recommendations. This paper investigates how knowledge graph embeddings can improve music recommendations. First, it is shown how a collaborative knowledge graph can be derived from open music data sources. Based on this knowledge graph, the music recommender system EARS (knowledge graph Embedding-based Artist Recommender System) is presented in detail, with particular emphasis on recommendation diversity and explainability. Finally, a comprehensive evaluation with real-world data is conducted, comparing of different embeddings and investigating the influence of different types of knowledge

Context-awareness in task automation services by distributed event processing

Everybody has to coordinate several tasks everyday, usually in a manual manner. Recently, the concept of Task Automation Services has been introduced to automate and personalize the task coordination problem. Several user centered platforms and applications have arisen in the last years, that let their users configure their very own automations based on third party services. In this paper, we propose a new system architecture for Task Automation Services in a heterogeneous mobile, smart devices, and cloud services environment. Our architecture is based on the novel idea to employ distributed Complex Event Processing to implement innovative mixed execution profiles. The major advantage of the approach is its ability to incorporate context-awareness and real-time coordination in Task Automation Services

Establishing service management in SOA

In service-oriented architectures the management of services is a crucial task during all stages of IT operations. Based on a case study performed for a group of finance companies the different aspects of service management are presented. First, the paper discusses how services must be described for management purposes. In particular, a special emphasis is placed on the integration of legacy/non web services. Secondly, the service lifecycle that underlies service management is presented. Especially, the relation to SOA governance and an appropriate tool support by registry repositories is outlined

Applying advisory agents on the semantic web for e-learning

In this article, we present the software architecture of a new generation of advisory systems using Intelligent Agent and Semantic Web technologies. Multi-agent systems provide a well-suited paradigm to implement negotiation processes in a consultancy situation. Software agents act as clients and advisors, using their knowledge to assist human users. In the presented architecture, the domain knowledge is modeled semantically by means of XML-based ontology languages such as OWL. Using an inference engine, the agents reason, based on their knowledge to make decisions or proposals. The agent knowledge consists of different types of data: on the one hand, private data, which has to be protected against unauthorized access; and on the other hand, publicly accessible knowledge spread over different Web sites. As in a real consultancy, an agent only reveals sensitive private data, if they are indispensable for finding a solution. In addition, depending on the actual consultancy situation, each agent dynamically expands its knowledge base by accessing OWL knowledge sources from the Internet. Due to the standardization of OWL, knowledge models easily can be shared and accessed via the Internet. The usefulness of our approach is proved by the implementation of an advisory system in the Semantic E-learning Agent (SEA) project, whose objective is to develop virtual student advisers that render support to university students in order to successfully organize and perform their studies

Using CEP-based blackboards for coordinating mobile RFID agents

In huge warehouses or stockrooms, it is often very difficult to find a certain item, because it has been misplaced and is therefore not at its assumed position. This position paper presents an approach on how to coordinate mobile RFID agents using a blackboard architecture based on Complex Event Processing

Modellierung und Analyse lastinduzierter Speicherfehler

Ein sehr großer Anteil der in Rechensystemen auftretenden Fehler ereignet sich im Speicher. In dieser Arbeit wird ein zerlegungsorientiertes Modell entwickelt, das die Wechselwirkungen zwischen Speicherfehlern und Systemleistung untersucht. Zunächst wird das Speicherverhalten eines Auftrags durch ein mehrphasiges Independent-Reference-Modell charakterisiert. Dies dient als Grundlage eines Modells zum Auftreten von Störungen, in das Lastcharakteristika wie die Auftrags-Verweildauer, die Seitenzugriffs-Rate und die Paging-Rate eingehen. Anschließend kann die Wahrscheinlichkeit, mit der ein Speicherfehler entdeckt wird, berechnet werden. Die zur Behandlung von Speicherfehlern erforderlichen Maßnahmen bestimmen die mittlere durch Fehler induzierte Last. Die Wechselwirkungen zwischen Fehler- und Leistungsverhalten werden durch ein System nichtlinearer Gleichung beschrieben, für dessen Lösung ein iteratives Verfahren abgeleitet wird. Abschließend wird mit ausführlichen Beispielen das Modell erläutert und der Einfluß einiger Modell-Parameter auf Leistungs- und Zuverlässigkeitskenngrößen untersucht

Speicher- und Prozessverwaltung

Das Kapitel (aus dem Buch "Mikrorechner-Systeme : Mikroprozessoren, Speicher, Peripherie", siehe Quelle) behandelt verschiedene Konzepte der Speicherverwaltung und stellt Bausteine vor, die diese Verwaltung hardwaremäßig durchführen. Außerdem werden verschiedene Maßnahmen zur Hardware-Unterstützung von Mikroprozessor-Betriebssystemen beschrieben

Integrating semantic knowledge in data stream processing

Complex Event Processing (CEP) has been established as a well-suited software technology for processing high-frequent data streams. However, intelligent stream based systems must integrate stream data with semantical background knowledge. In this work, we investigate different approaches on integrating stream data and semantic domain knowledge. In particular, we discuss from a software engineering per- spective two different architectures: an approach adding an ontology access mechanism to a common Continuous Query Language (CQL) is compared with C-SPARQL, a streaming extension of the RDF query language SPARQL

An architecture for situation-aware evacuation guidance in smart buildings

Smart Cities require reliable means for managing installations that offer essential services to the citizens. In this paper we focus on the problem of evacuation of smart buildings in case of emergencies. In particular, we present an abstract architecture for situation-aware evacuation guidance systems in smart buildings, describe its key modules in detail, and provide some concrete examples of its structure and dynamics