Decentralized Coalition Formation with Agent-based Combinatorial Heuristics

A steadily growing pervasion of the energy distribution grid with communication technology is widely seen as an enabler for new computational coordination techniques for renewable, distributed generation as well as for bundling with controllable consumers. Smart markets will foster a decentralized grid management. One important task as prerequisite to decentralized management is the ability to group together in order to jointly gain enough suitable flexibility and capacity to assume responsibility for a specific control task in the grid. In self-organized smart grid scenarios, grouping or coalition formation has to be achieved in a decentralized and situation aware way based on individual capabilities. We present a fully decentralized coalition formation approach based on an established agent-based heuristics for predictive scheduling with the additional advantage of keeping all information about local decision base and local operational constraints private. Two closely interlocked optimization processes orchestrate an overall procedure that adapts a coalition structure to best suit a given set of energy products. The approach is evaluated in several simulation scenarios with different type of established models for integrating distributed energy resources and is also extended to the induced use case of surplus distribution using basically the same algorithm

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Rezension zu: 1) Bender Walter/Zech, Rainer (Hrsg.): ... denn sie wissen, was sie tun! Auf dem Weg zur selbstreflexiven Organisation. Fallstudien zur Qualitätsentwicklung. Schriftenreihe für kritische Sozialforschung und Bildungsarbeit, Bd. 12. Hannover: Espressum Verl. 2007. ISBN 978-3-89069-014-8. 2) Göhlich, Michael; Wulf, Christoph; Zirfas, Jörg (Hrsg.): Pädagogische Theorien des Lernens. Weinheim: Beltz 2007. ISBN 978-3-407-32072-8. 3) Göhlich, Michael; König, Eckard; Schwarzer, Christine (Hrsg.): Beratung, Macht und organisationales Lernen. Wiesbaden: VS Verl. f. Sozialwiss. 2007. ISBN 978-3-531-15360-5. 4) Heimbach-Steins, Marianne; Kruip, Gerhard; Kunze, Axel Bernd: Das Menschenrecht auf Bildung und seine Umsetzung in Deutschland. Diagnose – Reflexionen – Perspektiven. Bielefeld: W. Bertelsmann 2007. ISBN 978-3-7639-3542-0. 5) Pallasch, Waldemar; Hameyer, Uwe: Lerncoaching - theoretische Grundlage und Praxisbeispiele zu einer didaktischen Herausforderung. Weinheim: Juventa 2008. ISBN 978-3-7799-2136-3. 6) Tippelt, Rudolf; Reich, Jutta; Hippel, Aiga v.; Barz, Heiner; Baum, Dajana: Weiterbildung und soziale Milieus in Deutschland. Bd. 3, Milieumarketing implementieren. Bielefeld: W. Bertelsmann 2008. ISBN 978-3-7639-1943-7. 7) Tödt, Katia: Lernerorientierte Qualitätstestierung für Bildungsveranstaltungen (LQB). Bielefeld: W. Bertelsmann 2008. ISBN 978-3-7639-3625-0. 8) Walber, Markus: Selbststeuerung im Lernprozess und Erkenntniskonstruktion: eine empirische Studie in der Weiterbildung. Münster: Waxmann 2007. ISBN 978-3-8309-1888-2. 9) Weil, Markus: Weiterbildungskooperation in KMU: eine Perspektive für berufs- und wirtschaftspädagogische Konzepte. Bern: h.e.p. Verl. 2006. ISBN 3-03905-234-9

Human embryonic stem cell-derived test systems for developmental neurotoxicity: a transcriptomics approach

Developmental neurotoxicity (DNT) and many forms of reproductive toxicity (RT) often manifest themselves in functional deficits that are not necessarily based on cell death, but rather on minor changes relating to cell differentiation or communication. The fields of DNT/RT would greatly benefit from in vitro tests that allow the identification of toxicant-induced changes of the cellular proteostasis, or of its underlying transcriptome network. Therefore, the 'human embryonic stem cell (hESC)- derived novel alternative test systems (ESNATS)' European commission research project established RT tests based on defined differentiation protocols of hESC and their progeny. Valproic acid (VPA) and methylmercury (MeHg) were used as positive control compounds to address the following fundamental questions: (1) Does transcriptome analysis allow discrimination of the two compounds? (2) How does analysis of enriched transcription factor binding sites (TFBS) and of individual probe sets (PS) distinguish between test systems? (3) Can batch effects be controlled? (4) How many DNA microarrays are needed? (5) Is the highest non-cytotoxic concentration optimal and relevant for the study of transcriptome changes? VPA triggered vast transcriptional changes, whereas MeHg altered fewer transcripts. To attenuate batch effects, analysis has been focused on the 500 PS with highest variability. The test systems differed significantly in their responses (\20 % overlap). Moreover, within one test system, little overlap between the PS changed by the two compounds has been observed. However, using TFBS enrichment, a relatively large 'common response' to VPA and MeHg could be distinguished from 'compound-specific' responses. In conclusion, the ESNATS assay battery allows classification of human DNT/RT toxicants on the basis of their transcriptome profiles.EU/FP7/ESNATSDFGDoerenkamp-Zbinden Foundatio