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In this paper, we consider robust stability analysis of large-scale sparsely interconnected uncertain systems. By modeling the interconnections among the subsystems with integral quadratic constraints, we show that robust stability analysis of such systems can be performed by solving a set of sparse linear matrix inequalities. We also show that a sparse formulation of the analysis problem is equiv
Stability of some decentralized traffic signal control policies for urban traffic networks is studied. It is proven that, whenever the arrival rates belong to a certain region -which is the largest where stability is possible- the resulting traffic network dynamics admit a globally asymptotically stable equilibrium. The results rely on the use of some entropy-like Lyapunov functions previously con
Reference attribute grammars (RAGs) is a powerful formalism for developing modular extensible compilers and program analysis tools. This paper presents JavaRAG, an implementation of RAGs as a Java library that is independent of the abstract syntax tree structure. This makes it possible to extend legacy compilers implemented in Java with RAG computations. We have evaluated the approach by integrati
We are concerned with software that can self-adapt to satisfy certain reliability requirements, in spite of adverse changes affecting the environment in which it is embedded. Self-adapting software architectures are heavily based on dynamic binding. The bindings among components are dynamically set as the conditions that require a self-adaptation are discovered during the system's lifetime. By ado
Feature quantization is a crucial component for efficient large scale image retrieval and object recognition. By quantizing local features into visual words, one hopes that features that match each other obtain the same word ID. Then, similarities between images can be measured with respect to the corresponding histograms of visual words. Given the appearance variations of local features, traditio
Popular Abstract in Swedish Eftersom gamla träd har blivit mycket ovanligare de senaste 200 åren, både i skogslandskapet och på ängs- och hagmarker, har djur som lever i gamla träd blivit mycket sällsyntare och många arter är utrotningshotade. I gamla ekar bildas ofta mulm i stammarnas håligheter. Mulmen består av murket trämjöl och i den lever en rik och specialiserad fauna som framför allt utgörMany species associated with old trees are threatened, as this habitat has decreased severely in Europe during the last 200 years. In old oaks, hollows with wood mould often form in the trunks and these harbour a specialized fauna mainly consisting of beetles, flies and pseudoscorpions. This thesis contains the first quantitative examination of the habitat requirements and population ecology of sp
We investigate the potential of different pre-fetchingand/or caching strategies for different user behaviour withrespect to surfing or browsing in a catch-up-TV network. To thisend we identify accounts and channels associated with strong orweak surfing or browsing respectively and study the distributionsof hold times for the different types of behaviour. Finally wepresent results from a request prWe investigate the potential of different pre-fetching and/or caching strategies for different user behaviour with respect to surfing or browsing in a catch-up-TV network. To this end we identify accounts and channels associated with strong or weak surfing or browsing respectively and study the distributions of hold times for the different types of behaviour. Finally we present results from a requ
Closed-loop positivity of feedback interconnections of positive monotone nonlinear systems is investigated. It is shown that an instantaneous gain condition on the open-loop systems which implies feedback well-posedness also guarantees feedback positivity. Furthermore, the notion of integral linear constraints (ILC) is utilised as a tool to characterise uncertainty in positive feedback systems. Ro
In this paper, we present two distributed algorithms to compute an equilibrium, that is optimal with respect to strictly convex and separable cost functions, for controlled traffic flow dynamics over networks under constant exogenous inflows. The dynamics is modeled in continuous time by the Cell Transmission Model and a non-FIFO Dynamic Network Loading Model, with traffic control. The two algorit
This paper designs distributed dynamic traffic signal control policies for urban traffic networks. Vehicles at the end of an approach to an intersection queue up in separate lanes corresponding to different possible turn maneuvers at the upcoming intersection, according to fixed turn ratios. The departure rate of vehicles from the queue is governed by traffic signal control at the intersections. W
Algorithms for secure encryption in a post-quantum world are currently receiving a lot of attention in the research community, including several larger projects and a standardization effort from NIST. One of the most promising algorithms is the code-based scheme called QC-MDPC, which has excellent performance and a small public key size. In this work we present a very efficient key recovery attack
In operating systems, resource managers are developed according to simplicity, low overhead, low memory footprint, extensibility and efficiency. Thread schedulers are designed and developed following these implementation-related guidelines. The performance of the implementation is then tested over a set of benchmarks. However, the ability to provide real-time guarantees of these policies is rarely
A Keyless Signing Infrastructure (KSI) provides users with a means to timestamp documents on a per-second basis. The KSI consists of a global infrastructure with several server layers and by using Merkle hash trees, the root hash can be used to verify the integrity and timestamp of a document. Regular publication of root hashes, e.g., once per month, allows a document to be verified without suppor
In conventional seismic surveys, there is a waiting time between sequentially fired shots. This time is determined such that the deepest reflection of interest is recorded before the following source is fired. In a survey with simultaneous or blended sources, the waiting time between the firing of shots is not dependent on the deepest reflection of interest, it is usually much shorter and/or can h
Operating systems code is often developed according to principles like simplicity, low overhead, and low memory footprint. Schedulers are no exceptions. A scheduler is usually developed with flexibility in mind, and this restricts the ability to provide real-time guarantees. Moreover, even when schedulers can provide real-time guarantees, it is unlikely that these guarantees are properly quantifie
Modern software should satisfy multiple goals simultaneously: it should provide predictable performance, be robust to failures, handle peak loads and deal seamlessly with unexpected conditions and changes in the execution environment. For this to happen, software designs should account for the possibility of runtime changes and provide formal guarantees of the software's behavior. Control theory i
