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Many distributed applications have to meet their performance or quality-of-service goals in environments where available resources change contantly. Important classes of distributed applications (including distributed multimedia codes, applications for mobile devices, and computational grid codes) use <i>runtime adaptation</i> in order to achieve their(More)
The Möbius modeling tool provides an infrastructure to support multiple interacting formalisms and solvers, and is extensible in that new formalisms and solvers can be added to the tool in such a way that they can interact with those already implemented without requiring additional changes to the previously implemented ones. We have continued to add(More)
Model-based control utilizes performance models of applications to choose performant system configurations for execution of applications. The performance models used in this research separate specification of the software system from specification of the execution environment so that model-based control can select software configurations for a given(More)
Despite the development of many modeling formalisms and model solution methods, most tool implementations support only a single formalism. Furthermore, models expressed in a chosen formalism cannot be combined to interact with models expressed in other formalisms. This chapter provides an overview of selected performance/dependability modeling tools(More)
Structured (a.k.a. symbolic) representation techniques of Markov models have, to a large extent, been used effectively for representing very large transition matrices and their associated state spaces. However, their success means that the largest space requirement encountered when analyzing these models is often the representation of their iteration and(More)
Despite the development of many modeling formalisms and model solution methods, most tool implementations support only a single formalism. Furthermore, models expressed in a chosen formalism cannot be combined with models expressed in other formalisms. This paper describes a modeling tool called Möbius, which provides an infrastructure to support multiple(More)
Major advances in Merged Logic DRAM (MLD) technology coupled with the popularization of memory-intensive applications provide fertile ground for architectures based on Intelligent Memory (IRAM) or Processors-in-Memory (PIM). The contribution of this paper is to explore one way to use the current state-of-the-art MLD technology for general-purpose computers.(More)
In this work, we present a first effort at quantitatively comparing the strengths and limitations of various intrusion-tolerant server architectures. We study four representative architectures, and use stochastic models to quantify the costs and benefits of each from both the performance and dependability perspectives. We present results characterizing(More)
Distributed Shared-Memory (DSM) multiprocessors provide an attractive combination of cost-effective commodity architecture and, thanks to the shared-memory abstraction, relative ease of programming. Unfortunately, it is well known that tuning applications for scalable performance in these machines is time-consuming. To address this problem, programmers use(More)
Henrik Bohnenkamp, Tod Courtney, David Daly, Salem Derisavi, Holger Hermanns Joost-Pieter Katoen, Ric Klaren, Vinh Vi Lam, William H. Sanders a Formal Methods and Tools Group, Department of Computer Science University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands b Coordinated Science Laboratory, Department of Electrical and Computer(More)