Thesis (MSc)--University of Stellenbosch, 2001. / ENGLISH ABSTRACT: lP networks offer scalability and flexibility for rapid deployment of value added lP services. However, with the increased demand and explosive growth of the Internet, carriers require a network infrastructure that is dependable, predictable, and offers consistent network performance. This thesis examines the functionality, performance and implementation aspects of the MPLS mechanisms to minimize the expected packet delay in MPLS networks. Optimal path selection and the assignment of bandwidth to those paths for minimizing the average packet delay are investigated. We present an efficient flow deviation algorithm (EFDA) which assigns a small amount of flow from a set of routes connecting each OD pair to the shortest path connecting the OD pair in the network. The flow is assigned in such a way that the network average packet delay is minimized. Bellman's algorithm is used to find the shortest routes between all OD pairs. The thesis studies the problem of determining the routes between an OD pair and assigning capacities to those routes. The EFDA algorithm iteratively determines the global minimum of the objective function. We also use the optimal flows to compute the optimal link capacities in both single and multirate networks. The algorithm has been applied to several examples and to different models of networks. The results are used to evaluate the performance of the EFDA algorithm and compare the optimal solutions obtained with different starting topologies and different techniques. They all fall within a close cost-performance range. They are all within the same range from the optimal solution as well. / AFRIKAANSE OPSOMMING: lP-netwerke voorsien die skaleerbaarheid en buigsaamheid vir die vinnige ontplooing van toegevoegde-waarde lP-dienste. Die vergrote aanvraag en eksplosiewe uitbreiding van die Internet benodig betroubare, voorspelbare en bestendige netwerkprestasie. Hierdie tesis ondersoek die funksionaliteit, prestasie en implementering van die MPLS(multiprotokoletiketskakel)- meganismes om die verwagte pakketvertraging te minimeer. Ons bespreek 'n doeltreffende algoritme vir vloei-afwyking (EFDA) wat 'n klein hoeveelheid vloei toewys uit die versameling van roetes wat elke OT(oorsprong-teiken)- paar verbind aan die kortste pad wat die OT-paar koppel. Die vloei word toegewys sodanig dat die netwerk se gemiddelde pakketvertraging geminimeer word. Bellman se algoritme word gebruik om die kortste roetes tussen alle OT-pare te bepaal. Die tesis bespreek die probleem van die bepaling van roetes tussen 'n OT-paar en die toewysing van kapasiteite aan sulke roetes. Die EFDA-algoritme bepaal die globale minimum iteratief. Ons gebruik ook optimale vloeie vir die berekening van die optimale skakelkapasiteite in beide enkel- en multikoers netwerke. Die algoritme is toegepas op verskeie voorbeelde en op verskillende netwerkmodelle. Die skakelkapasiteite word aangewend om die prestasie van die EFDAalgoritme te evalueer en dit te vergelyk met die optimale oplossings verkry met verskillende aanvangstopologieë en tegnieke. Die resultate val binne klein koste-prestasie perke wat ook na aan die optimale oplossing lê.

På Karolinska Universitetssjukhuset har det återkommande rapporterats om flödesavvikelser hos infusionspumpar. En hypotes är att pumpanvändare drar i infusionsaggregates silikondel när en infusion förbereds och att detta ger upphov till flödesavvikelser. Detta projekt fokuserar på att utreda om töjning av slangsetets silikondel kan orsaka flödesavvikelser. Projektet utvärderade tre grupper av slangset där två av grupperna bestod av infusionsaggregat vars silikondel töjdes till olika längder och en grupp fungerade som referensgrupp. Resultatet visar att silikondelen förlängs vid töjning samt att flödesavvikelser uppstår om töjningen är tillräckligt stor. Trots att flödesavvikelserna påvisats så bedöms töjningen som utförts vara mycket större än den töjning som utförts av vårdpersonalen. Därför bedömmer vi att flödesavvikelserna som rapporterats på Karolinska Universitetssjukhuset inte beror på denna typ av felhantering av slangset. / At Karolinska University Hospital, recurrent reports of flow deviations in infusion pumps have been observed. One hypothesis is that pump users pull the silicone component of the administration set when preparing an infusion, leading to flow deviations. This project focuses on investigating whether elongation of the silicone component of the administration set can cause flow deviations. The project evaluated three groups of administration sets, where two groups consisted of administration sets which were elongated to different lenghts, while one group served as reference group. Results show that elongation of the silicone component occurs and that flow deviations occur if the elongation is large enough. However, despite the observed flow deviations, the elongation performed in the study is considered much larger than what healthcare personnel typically apply. Therefore, we find it unlikely that the reported flow deviations at Karolinska University Hospital are due to mishandling of the administration set.