This paper discusses the relationship between tests and proofs with focus on a tool for UML and OCL models. Tests are thought of as UML object diagrams and theorems or properties which are to be checked are represented as OCL constraints, i.e., class invariants or operation preand postconditions. The paper shows for the UML and OCL tool USE (UML-based Specification Environment) how to trace and...

A distributed presentation of a regular language L is a system of communicating automata accepting L, where the constraint on distribution is given in the form of a distributed alphabet. We study such presentations in the assumption-commitment framework , where each process makes assumptions about other processes in the system. Symmetrically, each process makes commitments which the other proce...

The occurrence of unphysical negative concentrations in solutions to diffusion equations is a well known and severe problem. Especially in three dimensions finite element discretizations give qualitatively very poor results, while finite volume discretizations are much more stable. We investigate the cause of these instabilities and trace them back to constraints on the mesh. It turns out that ...

We develop scalable algorithms for regular and non-negative matrix completion. In particular, we base the methods on trace-norm regularization that induces a low rank predicted matrix. The regularization problem is solved via a constraint generation method that explicitly maintains a sparse dual and the corresponding low rank primal solution. We provide a new dual block coordinate descent algor...

In this paper new sufficient conditions are presented for the existence of a Lyapunov pair with a coupling rank constraint within a H∞ minimization framework derived using the bounded real lemma and the projection lemma. The conditions are then used to propose a Linear Matrix Inequality (LMI) sub-optimal method to solve the model order reduction problem of general non-square LTI systems with a ...

The Hubble Space Telescope (HST) detection of an extra-solar planet atmosphere in 2001 was a landmark step forward for the characterization of extrasolar planets. HST detected the trace element sodium, via the neutral atomic resonance doublet at 593 nm, in the tran-siting extrasolar giant planet HD 209458 b. In this paper I discuss the significance of this first ever extrasolar planet atmospher...

A non-blocking supervisory control problem to meet bounded time constraints for nondeterministic real-time discrete event systems (DESs) is addressed. To this end, notions of trace controllability and time controllability are introduced for the non-deterministic real-time DESs with respect to a timed language specification representing a bounded time constraint. The existence conditions of a no...

Supporting observation activity in a digital workspace environment is an idea that holds promise for improving groupware activity. In this paper, we focus on non-constraint equipped collective learning situations, that is to say without a given structure to the working process. We present a meta-model and an architecture of an observation station, to collect activity traces and to analyse them ...

Abstract. This paper considers the problem of optimizing the ratio Tr [W T AW ]/Tr [W T BW ] over all unitary matrices W with p columns, where A, B are two positive definite matrices. This problem is common in supervised learning techniques. However, because its numerical solution is typically expensive it is often replaced by the simpler optimization problem which consists of optimizing Tr [W ...

We consider the single-user computational cut-off rate for the complex Rayleigh flat fading spatio-temporal channel under a peak power constraint. Determination of the cutoff rate requires maximization of an average error exponent over all possible space-time codeword probability distributions. This error exponent is monotone decreasing in a measure of dissimilarity between pairs of codeword ma...