http://dl.gi.de/handle/20.500.12116/11859 2026-07-21T13:24:41Z http://dl.gi.de/handle/20.500.12116/12412 Ökonomie der elektronischen Literaturversorgung Optimale Tarifwahl beim Bezug elektronischer Zeitschriften Fladung, Rainer B.; Dugall, Berndt; König, Wolfgang How can academic library consortia provide access to literature despite increasing costs and decreasing budgets?In this paper, it is shown that making the fixed subscription rate variable by combining two relevant tariff models (flat-rate licence and pay-per-view) is an advantageous approach for consortia to react to the increasing (subscription) prices.A decision-making model is developed that considers the relevant parameters of pay-perview costs and user growth. The model is then applied to the Hessian library consortium (HeBIS). The empirical analysis shows that an optimal mix of rates for the publisher’s journals portfolio attains savings between 2% and 17% compared to a basic flat-rate licence. 2004-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/12411 Systeme für das Management digitaler Rechte Hess, Thomas; Ünlü, Vural Media companies and producers of intellectual property are currently threatened with massive information product piracy. Digital Rights Management Systems (DRMS) offer technical copyright protection measures to protect content against digital piracy. The authors give an overview about the status quo of DRMS from a functional, technical and architectural perspective. Apart from purely technological issues, it is also essential to take the economic aspects of DRMS into consideration. The trade-off between content protection and total cost of ownership of a DRMS installation will require the determination of a suitable level of technical copyright protection for a given context. 2004-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/12413 Effektivität von Lösungsansätzen zur Bekämpfung von Spam Schryen, Guido Spam as unsolicited email has certainly crossed the border of just being bothersome. In 2003, it surpassed legitimate email — growing to more than 50% of all Internet emails. Annually, it causes economic harms of several billion Euros. Fighting spam, beside legal approaches especially technical means are deployed in practical systems, mainly focussing on blocking and filtering mechanisms.This article introduces into the spam field and describes, assesses, and classifies the currently most important approaches against spam. 2004-01-01T00:00:00Z http://dl.gi.de/handle/20.500.12116/12410 Konstruktion von Referenzmodellierungssprachen Ein Ordnungsrahmen zur Spezifikation von Adaptionsmechanismen für Informationsmodelle Becker, Jörg; Delfmann, Patrick; Knackstedt, Ralf Construction of Reference Modeling Languages — A Framework for the Specification of Adaptation Mechanisms for Conceptual Information Models Reference modeling languages differ from each other as they use different model types (such as process or data models) and as they provide different mechanisms that allow an adaptation of the reference model to specific contexts. The developer of the reference modeling language has to decide which adaptation technique he wants to use (e. g. configuration, aggregation, instantiation, specialization or analogy construction) and which of these techniques he wants to integrate into the language specification. In this paper, these adaptation techniques are compared, and reference solutions for the specification of extended reference modeling languages are proposed. The introduced solutions are structured by a methodical framework that assigns modeling examples and meta-models as well as meta-meta-models to the different adaptation techniques. Based on this framework, possible combinations of configurative adaptation mechanisms with aggregative, instantiation based, specialization based and analogy construction based mechanisms are discussed. 2004-01-01T00:00:00Z