Modal µ-Calculus, Model Checking and Gauß Elimination

In this paper we present a novel approach for solving Boolean equation systems with nested minimal and maximal fixpoints. The method works by successively eliminating variables and reducing a Boolean equation system similar to Gauß elimination for linear equation systems. It does not require backtracking techniques. Within one framework we suggest a global and a local algorithm. In the context of model checking in the modal-calculus the local algorithm is related to the tableau methods, but has a better worst case complexity

Networks : On the relation of bi- and multivariate measures

Date of Acceptance: 28/04/2015 Acknowledgement The article processing charge was funded by the German Research Foundation (DFG) and the Albert Ludwigs University Freiburg in the funding programme Open Access PublishingPeer reviewedPublisher PD

Making the poor pay for public goods via microfinance: Economic and political pitfalls in the case of water and sanitation

This paper critically assesses microfinance's expansion into the provision of public goods. It focuses on the problem of public goods and collective action and refers to the specific example of water and sanitation. The microfinancing of water and sanitation is a private business model which requires households to recognise, internalise and capitalise the benefits from improved water and sanitation. This requirement is not assured. Water and sanitation, being closely linked to underlying common-pool resources, are public goods which depend on collective governance solutions. They also have shifting public/private characteristics and are merit goods which depend on networks to enable provision to take place. Two cases, from Vietnam and India, are presented and evaluated. Despite their dissimilar settings and institutional designs, evidence is found that both projects encountered similar and comparable problems at the collective level which individual microfinance loans could not address. The paper concludes that trying to make the poor pay for public goods runs into four pitfalls: politics, public capacity, values and equity. -- Das Papier untersucht die Auswirkungen von Mikrofinanzierung auf öffentliche Güter und kollektives Handeln am Beispiel der Errichtung von Wasser- und Sanitäranlagen in Ländern der Dritten Welt. Das zugrunde liegende private Geschäftsmodell geht davon aus, dass Haushalte mittels Mikrokredite die Vorteile verbesserter Wasser- und Sanitäreinrichtungen erkennen und sich auch finanziell zunutze machen können - diese Voraussetzung ist allerdings nicht gegeben. Zudem sind Wasser- und Sanitärversorgung meritorische Güter, für deren Bereitstellung Netzwerke erforderlich sind. Sie erfordern eine kollektive Verwaltung, weil sie sowohl öffentliche als auch private Merkmale aufweisen und mit Gemeinschaftsgütern eng verknüpft sind. Ausgangslage und institutionelle Rahmenbedingungen der beiden untersuchten Fallbeispiele in Vietnam und Indien sind unterschiedlich. Trotzdem geben die Ergebnisse der Studie Hinweise auf vergleichbare Probleme auf der kollektiven Ebene, die nicht über Mikrofinanzierung lösbar sind. Es zeigt sich, dass der Versuch, die Armen zur Finanzierung öffentlicher Güter zu bringen, an mehreren Hindernissen scheitert: an der lokalen Politik, einem unzureichend entwickelten öffentlichen Sektor, unterschiedlichen Wertvorstellungen und mangelnder Verteilungsgerechtigkeit.

A numerically efficient implementation of the expectation maximization algorithm for state space models

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Model checking embedded system designs

We survey the basic principles behind the application of model checking to controller verification and synthesis. A promising development is the area of guided model checking, in which the state space search strategy of the model checking algorithm can be influenced to visit more interesting sets of states first. In particular, we discuss how model checking can be combined with heuristic cost functions to guide search strategies. Finally, we list a number of current research developments, especially in the area of reachability analysis for optimal control and related issues