38,695 research outputs found
Process Mining as a Strategy of Inquiry: Understanding Design Interventions and the Development of Business Processes
Process (re-)design and improvement are important aspectsof the Business Process Management (BPM) life-cycle. Yet, there is lit-tle empirical evidence on how design interventions materialize in actualprocess execution, leading to repeated failure of such initiatives. In thisdissertation I use the emerging affordances of process mining algorithmsto address this important limitation. In particular, I devise a methodthat combines process mining and grounded theory to study processualphenomena. Consequently, this method is applied to investigate changein business processes. This thesis contributes to the body of knowledgein BPM and bordering disciplines by demonstrating how process min-ing can be used as a method to study processual phenomena. Furtherthis research sheds light on the impact of design interventions on actualprocess execution and vica versa
Notes on the applicability of contraction method for stable limit laws
We presented a proof for the classical stable limit laws under use of contraction method in combination with the Zolotarev metric. Furthermore, a stable limit law was proved for scaled sums of growing into sequences. This limit law was alternatively formulated for sequences of random variables defined by a simple degenerate recursion
A fully-coupled discontinuous Galerkin method for two-phase flow in porous media with discontinuous capillary pressure
In this paper we formulate and test numerically a fully-coupled discontinuous
Galerkin (DG) method for incompressible two-phase flow with discontinuous
capillary pressure. The spatial discretization uses the symmetric interior
penalty DG formulation with weighted averages and is based on a wetting-phase
potential / capillary potential formulation of the two-phase flow system. After
discretizing in time with diagonally implicit Runge-Kutta schemes the resulting
systems of nonlinear algebraic equations are solved with Newton's method and
the arising systems of linear equations are solved efficiently and in parallel
with an algebraic multigrid method. The new scheme is investigated for various
test problems from the literature and is also compared to a cell-centered
finite volume scheme in terms of accuracy and time to solution. We find that
the method is accurate, robust and efficient. In particular no post-processing
of the DG velocity field is necessary in contrast to results reported by
several authors for decoupled schemes. Moreover, the solver scales well in
parallel and three-dimensional problems with up to nearly 100 million degrees
of freedom per time step have been computed on 1000 processors
Young Massive Clusters: Their Population Properties, Formation and Evolution, and Their Relation to the Ancient Globular Clusters
This review summarises the main properties of Young Massive Clusters (YMCs),
including their population properties, particularly focusing on extragalactic
cluster samples. We discuss potential biases and caveats that can affect the
construction of cluster samples and how incompleteness effects can result in
erroneous conclusions regarding the long term survival of clusters. In addition
to the luminosity, mass and age distributions of the clusters, we discuss the
size distribution and profile evolution of the clusters. We also briefly
discuss the stellar populations within YMCs. The final part of the review
focusses on the connections between YMCs and the ancient globular clusters,
whether or not they are related objects and how we can use what we know about
YMC formation and evolution to understand how GCs formed in the early universe
and how they relate to galaxy formation/evolution.Comment: 33 pages. To appear in EES2015 - Stellar Clusters: benchmarks of
stellar physics and galactic evolution - eds. E. Moraux, Y. Lebreton and C.
Charbonne
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