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A service management toolkit for active networks
(1999)TIK ReportActive networking, where network nodes perform customized processing of packets, is a rapidly expanding field of research. This paper investigates the realization of service management on a Virtual Active Network (VAN), the key concept in our active network management framework [11]. A VAN can be seen as a thin (software) layer in an active networking environment, which creates a generic service abstraction, offered by the provider to the ...Report -
Fuzzy decision diagrams for the representation, analysis, and optimization of rule bases
(1999)TIK ReportWhen no expert knowledge is available, fuzzy if-then rules may be extracted from examples of performance of a system. For this, an a priori decision on the number of linguistic terms of the linguistic variables may be required. This may induce a "rigid granularity", usually finer than that actually required by the system. Fuzzy decision diagrams (FuDDs) are introduced as an efficient data structure to represent fuzzy rule bases and to ...Report -
Virtualizing active networks for Telecom environments
(1999)TIK ReportThe paper addresses the question on how the benefits of active networking, such as customized packet processing inside the network and flexible service management, can be realized in a telecom environment. More precisely, we ask: How can a network provider, whose infrastructure is based on active networking technology, support a large number of customers, all of which independently install and run their own customized active services in ...Report -
Fourier mode analysis of layers in shallow shell deformations
(1999)SAM Research ReportWe investigate here the length scales of the boundary or interior layer effects in shell deformation. Quantitative information on the layers is obtained by considering two (simplified) `shallow' shell models corresponding to the `classical' three-field (Love-Koiter-Novozhilov), resp. five-field (Reissner-Naghdi) shell models. We start by analysing the layers as functions of the thickness of the shell, while keeping the other geometric ...Report -
Fast numerical solution of the linearized Molodensky problem
(1999)SAM Research ReportWhen standard boundary element methods (BEM) are used to solve the linearized vector Molodensky problem we are confronted with two problems: (i) the absence of $O(|x|^{-2})$ terms in the decay condition is not taken into account, since the single layer ansatz, which is commonly used as representation of the perturbation potential, is of the order $O(|x|^{-1})$ as $x \to \infty$. This implies that the standard theory of Galerkin BEM is not ...Report -
The hp-Version of the Streamline Diffusion Finite Element Method in Two Space Dimensions
(1999)SAM Research ReportThe Streamline Diffusion Finite Element Method (SDFEM) for a two dimensional convection-diffusion problem is analyzed in the context of the hp-version of the Finite Element Method (FEM). It is proved that the appropriate choice of the SDFEM parameters leads to stable methods on the class of "boundary layer meshes" which may contain anisotropic needle elements of arbitrarily high aspect ratio. Consistency results show that the use of such ...Report -
Quality-of-Service based assessment of synchronization algorithms
(1999)TIK ReportIn this report we present a Quality-of-Service based methodology to assess synchronization algorithms. The methodology comprises two steps: Firstly, synchrinization algorithms are analized based on a defined set of QoS parameters for synchronization algorithms. Secondly, the analysis results are evaluated. The assessment methodology is validated by applying it to two well-known algorithms. Analysis and evaluation results as well as the ...Report -
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Optimized software synthesis for DSP using randomization techniques
(1999)TIK ReportThis paper addresses the problem of trading-off between the minimization of program and data memory requirements of single-processor implementations of dataflow programs. Based on the formal model of synchronous data flow (SDF) graphs, so called single appearance schedules are known to be program-memory optimal. Among these schedules, buffer memory schedules are investigated and explored based on a two-step approach: (1) An Evolutionary ...Report -
Numerical integration of differential algebraic systems and invariant manifolds
(1999)SAM Research ReportThe dynamics of a differential algebraic equation takes place on a lower dimensional manifold in phase space. Applying a numerical integration scheme, it is natural to ask if and how this geometric property is preserved by the discrete dynamical system. In the index-1 case answers to this question are obtained from the singularly perturbed case treated in [6] for Runge-Kutta methods and in [7] for linear multistep methods. As main result, ...Report