Content and Context Aware Strategies for QoS Support in VANETs

The increasing interest in autonomous coordinated driving and in proactive safety services, exploiting the wealth of sensing and computing resources which are gradually permeating the urban and vehicular environments, is making provisioning of high levels of QoS in vehicular networks an urgent issue. At the same time, the spreading model of a smart car, with a wealth of infotainment applications, calls for architectures for vehicular communications capable of supporting traffic with a diverse set of performance requirements. So far efforts focused on enabling a single specific QoS level. But the issues of how to support traffic with tight QoS requirements (no packet loss, and delays inferior to 1ms), and of designing a system capable at the same time of efficiently sustaining such traffic together with traffic from infotainment applications, are still open. In this paper we present the approach taken by the CONTACT project to tackle these issues. The goal of the project is to investigate how a VANET architecture, which integrates content-centric networking, software-defined networking, and context aware floating content schemes, can properly support the very diverse set of applications and services currently envisioned for the vehicular environment.

A multi-level stakeholder approach to sustainable land management

Soils provide us with over 90% of all human food, livestock feed, fibre and fuel on Earth. Soils, however, have more than just productive functions. The key challenge in coming years will be to address the diverse and potentially conflicting demands now being made by human societies and other forms of life, while ensuring that future generations have the same potential to use soils and land of comparable quality. In a multi-level stakeholder approach, down-to-earth action will have to be supplemented with measures at various levels, from households to communities, and from national policies to international conventions. Knowledge systems, both indigenous and scientific, and related research and learning processes must play a central role. Ongoing action can be enhanced through a critical assessment of the impact of past achievements, and through better cooperation between people and institutions.

WEAVE: Efficient Geographical Routing in Large-Scale Networks

We propose WEAVE, a geographical 2D/3D routing protocol that maintains information on a small number of waypoints and checkpoints for forwarding packets to any destination. Nodes obtain the routing information from partial traces gathered in incoming packets and use a system of checkpoints along with the segments of routes to weave end-to-end paths close to the shortest ones. WEAVE does not generate any control traffic, it is suitable for routing in both 2D and 3D networks, and does not require any strong assumption on the underlying network graph such as the Unit Disk or a Planar Graph. WEAVE compares favorably with existing protocols in both testbed experiments and simulations.

Der Einfluss der Spezifität des Humankapitals auf die Frage des Sourcings von Anwendungssoftware-Dienstleistungen

Seit geraumer Zeit wird die Frage kontrovers diskutiert, unter welchen Umständen es für ein Unternehmen vorteilhaft ist, bestimmte Funktionen der Informationsverarbeitung fremd zu beziehen. Während die einen die Risiken des Outsourcings betonen, indem sie auf den Verlust strategischer Potenziale und erhöhter Transaktionskosten verweisen, sprechen andere von strategischem Outsourcing und hohen Potenzialen der Kosteneinsparung. Der vorliegende Beitrag untersucht die Umstände, unter denen die strategischen Potenziale intern besser ausgeschöpft werden und die Produktions- und Transaktionskosten intern niedriger ausfallen als beim Fremdbezug. Eine zentrale Rolle spielen hierbei das Ausmaß der Spezifität des Humankapitals, Unterschiede in der Vertrauenswürdigkeit und der Motivation zwischen internen und externen Mitarbeitern sowie im Falle des Outsourcings die Höhe der Kapitalbeteiligung am externen Dienstleister. Aus drei komplementären Theorien wird ein Bezugsrahmen entwickelt und auf Basis einer schriftlichen Befragung von 139 deutschen Unternehmen empirisch getestet.

The Impact of Human Asset Specificity on the Sourcing of Application Services

The question concerning the circumstances under which it is advantageous for a company to outsource certain information systems functions has been a controversial issue for the last decade. While opponents emphasize the risks of outsourcing based on the loss of strategic potentials and increased transaction costs, proponents emphasize the strategic benefits of outsourcing and high potentials of cost-savings. This paper brings together both views by examining the conditions under which both the strategic potentials as well as savings in production and transaction costs of developing and maintaining software applications can better be achieved in-house as opposed to by an external vendor. We develop a theoretical framework from three complementary theories and test it empirically based on a mail survey of 139 German companies. The results show that insourcing is more cost efficient and advantageous in creating strategic benefits through IS if the provision of application services requires a high amount of firm specific human assets. These relationships, however, are partially moderated by differences in the trustworthiness and intrinsic motivation of internal versus external IS professionals. Moreover, capital shares with an external vendor can lower the risk of high transaction costs as well the risk of loosing the strategic opportunities of an IS.

Context Aware e-Learning Objects and their Types from the Perspective of the Object-Oriented Paradigm

The contribution of this article demonstrates how to identify context-aware types of e-Learning objects (eLOs) derived from the subject domains. This perspective is taken from an engineering point of view and is applied during requirements elicitation and analysis relating to present work in constructing an object-oriented (OO), dynamic, and adaptive model to build and deliver packaged e-Learning courses. Consequently, three preliminary subject domains are presented and, as a result, three primitive types of eLOs are posited. These types educed from the subject domains are of structural, conceptual, and granular nature. Structural objects are responsible for the course itself, conceptual objects incorporate adaptive and logical interoperability, while granular objects congregate granular assets. Their differences, interrelationships, and responsibilities are discussed. A major design challenge relates to adaptive behaviour. Future research addresses refinement on the subject domains and adaptive hypermedia systems.

Music Piracy on Peer-to-Peer Networks

Content providers from the music industry argue that peer-to-peer (P2P) networks such as KaZaA, Morpheus, iMesh, or Audiogalaxy are an enormous threat to their business. They furthermore blame these networks for their recent decline in sales figures. For this reason, an empirical investigation was conducted during a period of 6 weeks on one of the most popular files-sharing systems, in order to determine the quantity and quality of pirated music songs shared. We present empirical evidence as to what extent and in which quality music songs are being shared. A number of hypotheses are outlined and were tested. We studied, among other things, the number of users online and the number of flies accessible on such networks, the free riding problem, and the duration per search request. We further tested to see if there are any differences in the accessibility of songs based on the nationality of the artist, the language of the song, and the corresponding chart position. Finally, we outline the main hurdles users may face when downloading illegal music and the probability of obtaining high quality music tracks on such peer-to-peer networks.

Forecasting Intraday Stock Price Trends with Text Mining Techniques

In this paper, we describe NewsCATS (news categorization and trading system), a system implemented to predict stock price trends for the time immediately after the publication of press releases. NewsCATS consists mainly of three components. The first component retrieves relevant information from press releases through the application of text preprocessing techniques. The second component sorts the press releases into predefined categories. Finally, appropriate trading strategies are derived by the third component by means of the earlier categorization. The findings indicate that a categorization of press releases is able to provide additional information that can be used to forecast stock price trends, but that an adequate trading strategy is essential for the results of the categorization to be fully exploited.

Decision Support Models for Composing and Navigating through e-Learning Objects

Libraries of learning objects may serve as basis for deriving course offerings that are customized to the needs of different learning communities or even individuals. Several ways of organizing this course composition process are discussed. Course composition needs a clear understanding of the dependencies between the learning objects. Therefore we discuss the metadata for object relationships proposed in different standardization projects and especially those suggested in the Dublin Core Metadata Initiative. Based on these metadata we construct adjacency matrices and graphs. We show how Gozinto-type computations can be used to determine direct and indirect prerequisites for certain learning objects. The metadata may also be used to define integer programming models which can be applied to support the instructor in formulating his specifications for selecting objects or which allow a computer agent to automatically select learning objects. Such decision models could also be helpful for a learner navigating through a library of learning objects. We also sketch a graph-based procedure for manual or automatic sequencing of the learning objects.

Object-Based Customization of Learning Content: Potentials and Pitfalls

Specification consortia and standardization bodies concentrate on e-Learning objects to en-sure reusability of content. Learning objects may be collected in a library and used for deriv-ing course offerings that are customized to the needs of different learning communities. How-ever, customization of courses is possible only if the logical dependencies between the learn-ing objects are known. Metadata for describing object relationships have been proposed in several e-Learning specifications. This paper discusses the customization potential of e-Learning objects but also the pitfalls that exist if content is customized inappropriately.

Analyse der ERP-Outsourcingentscheidung im Spannungsfeld von technologischem und unternehmensbezogenem Wissen

Im letzten Jahrzehnt haben ERP-Systeme eine hohe Verbreitung in der Wirtschaft erfahren. Oftmals wird ihnen die Rolle einer "mission critical"-Anwendung für die Aufrechterhaltung des Geschäftsbetriebs zugeschrieben. Innerhalb der Phasen der Auswahl, Implementierung und Stabilisierung sowie dem Betrieb und der Verbesserung des ERP-Systems greifen viele Unternehmen auf die Unterstützung externer Dienstleister zurück. Manche Unternehmen lagern im Zuge der Entscheidung für ein ERP-Paket sogar ihre gesamte interne Informationsverarbeitung aus. In dem Beitrag wird analysiert, wie verschiedene Wissenskategorien die Entscheidung über das Outsourcing wesentlicher Aufgaben, die im Rahmen des ERP-Lebenszyklus anfallen, beeinflussen. Auf Basis der Erkenntnisse aus der bisherigen Literatur zum Outsourcing der Informationsverarbeitung werden die wesentlichen wissensbezogenen Entscheidungsdeterminanten des Outsourcing der Informationsverarbeitung herausgearbeitet und in einem Strukturmodell zusammengefasst. Es zeigt sich, dass insbesondere die Beurteilung der internen Ressourcen und Fähigkeiten gegenüber dem Markt und die Spezifität des technologischen Wissens und des Unternehmenswissens die Outsourcingentscheidung beeinflussen. In einem zweiten Schritt wird ein Bezugsrahmen entwickelt, mit dessen Hilfe die einzelnen Aufgaben des ERP-Lebenszyklus verschiedenen Wissenskategorien sowie internen und externen Aufgabenträgern zugeordnet werden können. Anhand eines Beispiels wird illustriert, wie die in der Literatur ermittelten Entscheidungsdeterminanten des Outsourcing der Informationsverarbeitung als Kriterien der Zuordnung angewendet werden können.

Modularity and Integrity Issues in Instructional Engineering

Course materials for e-learning are a special type of information system (IS). Thus, in the development of educational material one may learn from principles, methods, and tools that originated in the Software Engineering (SE) discipline and that are relevant in similar ways in "Instructional Engineering". An important SE principle is mo dularization, which supports properties like reusability and adaptability of code. To foster the adaptability of courseware we present a concept in which learning material is organized as a library of modular course objects. A certain lecturer may customize the courseware according to his specific course requirements. He must consider logical dependencies of and relationship integrity between selected course objects. We discuss integrity issues that have to be regarded for the composition of consistent course materials.