The single server semi-markov queue

A general model for the single server semi-Markov queue is studied. Its solution is reduced to a matrix factorization problem. Given this factorization, results are obtained for the distributions of actual and virtual waiting times, queue lengths both at arrival epochs and in continuous time, the number of customers during a busy period, its length and the length of a busy cycle. Two examples are discussed for which explicit factorizations have been obtained

A numerical solution for the multi-server queue with hyper-exponential service times

In this paper we present a numerical method for the queue GI/H2/s, which is based on general results for GI/Hm/s. We give a complete description of the algorithm which yields exact results for the steady distributions of the actual waiting time, the virtual waiting time and the number of customers in the system both at arrival epochs and in continuous time

Sugar quotas: yes or no? : economic consequences for sector, chain, international market situation and third world

Het ministerie van EL&I heeft het LEI gevraagd inzicht te verschaffen in de argumenten voor en tegen voortzetting van het centrale element van de huidige suikermarktordening, de quotering, na september 2015. De centrale vraag daarbij is: Wat zijn de gevolgen voor telers, verwerkende industrie, de andere schakels in de suikerketen en andere belanghebbenden in met name Nederland van voortzetting respectievelijk een fundamentele verandering van het Europese suikerbeleid? De resultaten in dit rapport zijn gebaseerd op literatuuronderzoek, waarmee de factoren die een rol spelen in de suikermarkt zijn geïnventariseerd, en op de toepassing van een aantal modellen. Met de modellen zijn aan de hand van een aantal uitgangspunten de effecten van beleidsveranderingen voor onder meer de productie van suiker, de oppervlakte suikerbieten en de inkomens van suikerbietentelers en de toegevoegde waarde en de werkgelegenheid in het akkerbouwcomplex in Nederland ingeschat

Sphaleron transition rate at high temperature in the 1+1 D abelian Higgs model

New results for the rate are presented using the canonical ensemble in the classical approximation on a spatial lattice. We find that the rate at high temperatures is proportional to $T^2$, and strongly dependent on the lattice spacing $a$. We conclude that a better effective action is needed for the classical approximation.Comment: 3 pages, uuencoded compressed postscript file, contribution to the Conference Proceedings "LATTICE 94", Bielefeld- German

Analyzing the Cutting Process of a Heated Flexible Blade in Extruded Polystyrene Foam

For the “Free Form Thick Layered Object Manufacturing” technology that is being developed at the Delft University, it is vital that Extruded Polystyrene Foam (XPS) can be cut accurately with a heated blade. The shape of the blade is actively controlled during the cutting process, which results in double curved cutting surfaces. In order to make this cutting process controllable it must be known how the cutting behavior is under varying conditions, like cutting speed, cutting angle and heating power. The authors executed a range of experiments, analyzed the results and describe a practical model for the cutting process of XPS with a heated blade.Mechanical Engineerin