Technical University of Dortmund

About: Technical University of Dortmund is a education organization based out in Dortmund, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Large Hadron Collider & Neutrino. The organization has 13028 authors who have published 27666 publications receiving 615557 citations. The organization is also known as: Dortmund University & University of Dortmund.

On the correspondence between conformance testing and regular inference

Abstract: Conformance testing for finite state machines and regular inference both aim at identifying the model structure underlying a black box system on the basis of a limited set of observations. Whereas the former technique checks for equivalence with a given conjecture model, the latter techniques addresses the corresponding synthesis problem by means of techniques adopted from automata learning. In this paper we establish a common framework to investigate the similarities of these techniques by showing how results in one area can be transferred to results in the other and to explain the reasons for their differences.

Transient Optical Spectra of a Dense Exciton Gas in a Direct-Gap Semiconductor

Abstract: The observation is reported of a remarkable persistence of the $1s$ exciton resonance in transient picosecond absorption spectra of GaAs under conditions of resonant optical excitation up to pair densities two orders of magnitude above the Mott density. The stability (excess linewidth 0.8 meV at $n=6\ifmmode\times\else\texttimes\fi{}{10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$) of this dense exciton gas against decay into the energetically more favorable continuum of electron-hole pairs is due to the relatively weak self-screening of discrete excitons.

Traffic modeling and characterization for UMTS networks

Abstract: In this paper, we present a synthetic traffic model for the Universal Mobile Telecommunication Systems (UMTS) based on measured trace data. The analysis and scaling process of the measured trace data with respect to different bandwidth classes constitutes the basic concept of the UMTS traffic characterization. Furthermore, we introduce an aggregated traffic model for UMTS networks that is analytically tractable. The key idea of this aggregated traffic model lies in customizing the batch Markovian arrival process (BMAP) such that different packet sizes of IP packets are represented by rewards (ie, batch sizes of arrivals) of the BMAP. The effectiveness of the customized BMAP for modeling UMTS traffic is illustrated using the synthetic traffic model previously presented.