Einsatz Domänen-spezifischer Sprachen für Komponenten-basierte Web Anwendungen

In Projekten zur Entwicklung verteilter Web-basierter Systeme stellt die Spezifikation der zu entwickelnden Lösung eine zeitintensive Aufgabe dar, bei der häufig Kommunikationsschwierigkeiten zwischen Kunden, Anwendern und Entwicklern auftreten. Domänen-spezifische Sprachen (DSLs) bieten sich hier aufgrund ihrer Nähe zur Problemdomäne und der damit einhergehenden leichteren Erlernbarkeit und Verständlichkeit als ideale Alternative zu schwergewichtigen Modellierungsmethoden an. Dieser Beitrag präsentiert einen Ansatz zur Entwicklung von Web Anwendungen durch Komposition hochgradig konfigurierbarer Fachkomponenten und deren Konfiguration mittels DSLProgrammen

From Cross-Organizational Business Process to Public Services

Service-oriented architectures promise flexible process integration in heterogeneous environments, particularly in cross organizational contexts. Therefore, a systematic approach for deriving service definitions from cross-organizational business processes is required. The paper at hand presents a structured, model driven approach that allows for cross-organizational integration with service-oriented concepts and technologies based on a cross-organizational business process. The resulting method is specified by means of a metamodel and a procedure model. Taking into account existing approaches in the research field, the paper focuses on the activities for the service design specification and the subsequent implementation of the public services. Feasibility of the method is shown by applying it in a Business-to-Government (B2G) real-world scenario, namely the collaboration between a consigning company and customs authorities according to the new European harmonized customs procedures

Dielectronic recombination and stability of warm gas in AGN

Understanding the thermal equilibrium (stability) curve may offer insights into the nature of the warm absorbers often found in active galactic nuclei. Its shape is determined by factors like the spectrum of the ionizing continuum and the chemical composition of the gas. We find that the stability curves obtained under the same set of the above mentioned physical factors, but using recently derived dielectronic recombination rates, give significantly different results, especially in the regions corresponding to warm absorbers, leading to different physical predictions. Using the current rates we find a larger probability of having thermally stable warm absorber at 10^5 \kel than previous predictions and also a greater possibility for its multiphase nature. the results obtained with the current dielectronic recombination rate coefficients are more reliable because the warm absorber models along the stability curve have computed coefficient values, whereas previous calculations relied on guessed averages for the same due to lack of available data.Comment: 5 pages, 3 figures, Accepted for publication in MNRAS Letters. The definitive version is available at http://www3.interscience.wiley.com/cgi-bin/hom