@misc{BrandtBrandt, author = {Brandt, Andreas and Brandt, Manfred}, title = {On the Moments of the Overflow and Freed Carried Traffic for the GI/M/C/0 System}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-6355}, number = {01-09}, abstract = {In circuit switching networks call streams are characterized by their mean and peakedness (two-moment method). The \$GI/M/C/0\$ system is used to model a single link, where the \$GI\$-stream is determined by fitting moments appropriately. For the moments of the overflow traffic of a \$GI/M/C/0\$ system there are efficient numerical algorithms available. However, for the moments of the freed carried traffic, defined as the moments of a virtual link of infinite capacity to which the process of calls accepted by the link (carried arrival process) is virtually directed and where the virtual calls get fresh exponential i.i.d.\ holding times, only complex numerical algorithms are available. This is the reason why the concept of the freed carried traffic is not used rigorously. The main result of this paper is an efficient algorithm for computing the moments of the freed carried traffic, in particular an explicit formula for its peakedness. This result offers a unified handling of both overflow and carried traffics in networks. Furthermore, some refined characteristics for the overflow and freed carried streams are derived.}, language = {en} } @misc{BoeingKoepf, author = {B{\"o}ing, Harald and Koepf, Wolfram}, title = {Algorithms for q-hypergeometric Summation in Computer Algebra}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-3453}, number = {SC-98-02}, abstract = {In this paper we present a short description of \$q\$-analogues of Gosper's, Zeilberger's, Petkov\v{s}ek's and related algorithms. Furthermore we introduce our corresponding MAPLE implementations and show how they can be applied to prove or even derive identities associated with \$q\$-series.}, language = {en} }