Modular Workflow Engine for Distributed Services using Lightweight Java Clients

In this article we introduce the concept and the first implementation of a lightweight client-server-framework as middleware for distributed computing. On the client side an installation without administrative rights or privileged ports can turn any computer into a worker node. Only a Java runtime environment and the JAR files comprising the workflow client are needed. To connect all clients to the engine one open server port is sufficient. The engine submits data to the clients and orchestrates their work by workflow descriptions from a central database. Clients request new task descriptions periodically, thus the system is robust against network failures. In the basic set-up, data up- and downloads are handled via HTTP communication with the server. The performance of the modular system could additionally be improved using dedicated file servers or distributed network file systems. We demonstrate the design features of the proposed engine in real-world applications from mechanical engineering. We have used this system on a compute cluster in design-of-experiment studies, parameter optimisations and robustness validations of finite element structures.Comment: 14 pages, 8 figure

Competition between social and private rental housing

In the context of shifting regulatory approaches and changing provision structures in many Western rental housing systems, the notion of competition between social and private rental housing has received increasing attention from practitioners and academic researchers. This thesis explores and theorises the concept of inter-tenure competition in order to advance understanding of what it means in local and national market realities, as well as in business and political practices. Results indicate that competition in mixed markets is a complex matter, much of which is explained by the distinctive properties of social and private rental services. Inter-tenure competition is shown to be the interplay of structural and political conditions, individual and organisational business goals, and the perceptions and strategic decisions of both providers and consumers. The results suggest that the degree of competition relates to specific points in time and is mainly a question of which rental market segment one is looking at. &nbsp

Filtering fundamental rights

oai:intr2dok.vifa-recht.de:mir_mods_0001383

Book review: Nick Gallent: Whose Housing Crisis? Assets and Homes in a Changing Economy

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Rupture cascades in a discrete element model of a porous sedimentary rock

We investigate the scaling properties of the sources of crackling noise in a fully-dynamic numerical model of sedimentary rocks subject to uniaxial compression. The model is initiated by filling a cylindrical container with randomly-sized spherical particles which are then connected by breakable beams. Loading at a constant strain rate the cohesive elements fail and the resulting stress transfer produces sudden bursts of correlated failures, directly analogous to the sources of acoustic emissions in real experiments. The source size, energy, and duration can all be quantified for an individual event, and the population analyzed for their scaling properties, including the distribution of waiting times between consecutive events. Despite the non-stationary loading, the results are all characterized by power law distributions over a broad range of scales in agreement with experiments. As failure is approached temporal correlation of events emerge accompanied by spatial clustering.Comment: 5 pages, 4 figure