Large scale wave propagation simulation is currently achievable in reasonable turnaround times by using distributed computing in multiple cpu clusters. However, if one needs to perform many such simulations, as is the case in optimization, tomography, or seismic imaging, then the resources required are still prohibitive. Model order reduction of large dynamical systems has been successfully use...

This paper considers the problem of passing from a nonlinear simple-structure model to a low-order approximation by preserving simplicity. The approximation problem is often best posed as an `2 optimization problem. This optimization problem is the core of our order reduction method so-called system matrices optimization. The simplification is formulated as special secondary conditions which ca...

Modeling of real time system posses a large number of problems. It is a challenging task to model accurately a large real time system. Modeling of large real time systems results in large number of differential or difference equations that lead to state variable or transfer function models that represents a higher order system. It is very difficult to handle such a higher order system model for...

In this paper, we present a new partial order reduction algorithm that can help reduce both space and time requirements of on-the-fly explicit enumeration based verifiers. The partial order reduction algorithms described in [God95, HP94, Pel94, Pel96] were observed to yield very little savings in many practical examples. The reason was traced to the proviso in these algorithms that often caused...

Security protocols are concurrent processes that communicate using cryptography with the aim of achieving various security properties. Recent work on their formal verification has brought procedures and tools for deciding trace equivalence properties (e.g., anonymity, unlinkability, vote secrecy) for a bounded number of sessions. However, these procedures are based on a naive symbolic explorati...

We investigate one of the classical problems of the theory of term rewriting, namely termination. We present an ordering for comparing higher-order terms that can be utilized for testing termination and decreasingness of higher-order conditional term rewriting systems. The ordering relies on a rst-order interpretation of higher-order terms and a suitable extension of the RPO. 1 Motivation Term ...

This Chapter contains three advanced topics in model order reduction (MOR): nonlinear MOR, MOR for multi-terminals (or multi-ports) and finally an application in deriving a nonlinear macromodel covering phase shift when coupling oscillators. The Sections are offered in a prefered order for reading, but can be read independentlty. Section 5.1, written by Michael Striebel and E. Jan W. ter Maten,...

Feedback control of fluids is often achieved with limited state measurements. Effective approaches utilize compensators, which can be computed using linear quadratic Gaussian (LQG) or MinMax control designs. However, to achieve real-time control algorithms, these compensators must have low computational complexity. Model reduction methods are a natural choice to build reduced-order compensators...

The simulation of electric rotating machines is both computationally expensive and memory intensive. To overcome these costs, model order reduction techniques can be applied. The focus of this contribution is especially on machines that contain non-symmetric components. These are usually introduced during the mass production process and are modeled by small perturbations in the geometry (e.g., ...

Partial order based reduction techniques to reduce time and memory in model-checking procedures are becoming quite popular. Partial order reduction techniques exploit the independence of actions. Symmetry based reduction techniques exploit the inherent structure of the system to reduce the state space explored during model checking. We provide an abstract framework for combining partial-order a...