Mark-Oliver Stehr

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We present the cognitive radio (policy) language (CoRaL), a new language for expressing policies that govern the behavior of cognitive radios that opportunistically share spectrum. A Policy Reasoner validates radio transmissions to ensure that they are compliant with the spectrum policies. The Policy Reasoner also discovers spectrum sharing opportunities by(More)
Howe's HOL/Nuprl connection is an interesting example of a translation between two fundamentally different logics, namely a typed higher-order logic and a polymorphic extensional type theory. In earlier work we have established a proof-theoretic correctness result of the translation in a way that complements Howe's semantics-based justification and(More)
We propose a new distributed and parallel meta-heuristic framework to address the issues of scalability and robustness in the optimization problem. The proposed framework, named PADO (Parallel And Distributed Optimization framework), can utilize heterogeneous computing and communication resources to achieve scalable speedup while maintaining high solution(More)
Given the diierent perspectives from which a complex software system has to be analyzed, the multiplicity of formalisms is in some sense unavoidable. This poses two important technical challenges: how to rigorously meet the need to interrelate formalisms, and how to reduce the duplication of eeort in tool and speciication building across formalisms. These(More)
We propose rewriting logic as a unifying framework for a wide range of Petri nets models. We treat in detail place/transition nets and important extensions of the basic model by individual tokens, test arcs, and time. Based on the idea that " Petri nets are monoids " suggested by Meseguer and Montanari we define a rewriting semantics that maps(More)
PLAN is a language designed for programming active networks, and can more generally be regarded as a model of mobile computation. PLAN generalizes the paradigm of imperative functional programming in an elegant way that allows for recursive, remote function calls, and it provides a clear mechanism for the interaction between host and mobile code. Techniques(More)
We present a new language for expressing policies that allow opportunistic spectrum access while not causing interference. CoRaL has expressive constructs for numerical constraints, supports efficient reasoning, and will be verifiable. The language is extensible so that unanticipated policy types can be encoded. We also describe a Policy Reasoner that(More)