We identify the statistical characterizers of congestion and decongestion for message transport in model communication lattices. These turn out to be the travel time distributions, which are Gaussian in the congested phase, and logarithmic normal in the decongested phase. Our results are demonstrated for two-dimensional lattices, such the Waxman graph, and for lattices with local clustering and...

We address interactive voice services over Best E ort packet networks where tra c is subject to unpredictable congestions. The quality of voice services can be signi cantly a ected by network delay and jitter due to the rejection of late packets. LIFO has proven to be an interesting overload strategy in delay constrained systems. We propose the use of the LIFO discipline in the context of conge...

This paper aims to propose a reliable location-allocation model where facilities are subject to the risk of disruptions. Since service facilities are expected to satisfy random and heavy demands, we model the congested situations in the system within a queuing framework which handles two sources of uncertainty associated with demand and service. To insure the service quality, a minimum limit re...

RED-BORDERED FORM Coming from Australia iii ABSTRACT In this thesis, a linear programming algorithm is developed for determining a measure of market concentration in congested transmission systems. The linear program uses the effects of the congestors on the system to derate the line limits of each transmission line. The derated line limits allow for the congestor's contribution to the system f...

There exist various service systems that have hierarchical structure. In hierarchical service networks, facilities at different levels provide different types of services. For example, in health care systems, general centers provide low-level services such as primary health care services, while the specialized hospitals provide high-level services. Because of demand congestion in service networ...

Time prediction in healthcare systems such as outpatient clinics, hospital wards, and emergency departments is an essential component of decision making. Predictions are used for effective and efficient resource allocation, optimised ambulance routing, and accurate delay announcement. In this work, we focus on time prediction in congested healthcare systems, where patients share scarce resource...

Focusing on resource cycles, the authors developed a semiconductor wafer factory (fab) simulation that executed more than an order of magnitude faster than a job-tracing simulation previously in use. The authors summarize the methodologies used and conclude that the differences in execution speeds are due to the fundamental differences in using an event graph paradigm to model the discrete even...