SIMULATION: Transactions of The Society for Modeling and Simulation International

Wildberger, A. Martin

doi: 10.1177/003754979506400201pmid: N/A

Kalyoncu, Hakan; Sankur, Bülent

doi: 10.1177/003754979506400202pmid: N/A

A simulation method for performance estimation and dimensioning a medical picture archival and communications system (PACS) is introduced. The introduced method makes use of a source layer model to simulate the behavior of a typical PACS user and server. As a case study for the application of the proposed methodology, the problem of dimensioning the PACS of a radiology department with a multitude of users and modalities is considered. Furthermore, the effect of additional database servers on the system performance is considered. Results are presented for two cases: i) for the system with radiologists, modalities, and database server(s); ii.) with modality traffic postponed to off hours, i.e., for the system with database server(s) and radiologists onl y.

Friedman, Linda W.; Friedman, Hershey H.

doi: 10.1177/003754979506400203pmid: N/A

There are many situations in which parametric statistical techniques are less than ideal for evaluating a simulated system. For most simulation output, one must rely heavily on the central limit theorein in order to apply parametric statistical techniques. The bootstrap statistic is a nonparametric sample-resample technique that makes no distributional assumptions and may be used for estimation and hypothesis testing. The authors propose the bootstrap as a valuable tool for the analysis of simulation output data since it can be used in situations in which either the distribution is not known or normal approximations are inappropriate. Furthermore, since bootstrapping is itself a simulation technique it is inherently satisfying as a tool for the analysis of simulation output data. Illustrations are presented.

Lin, Yi-Bing

doi: 10.1177/003754979506400204pmid: N/A

Parallel independent replicated simulation (PIRS) is an effective approach to speed up the simulation processes. In a PIRS, amultiple simulation runs are executed independently computers in parallel. The statistical properties for a PIRS may be affected by the scheduling policies. For an unbiased PIRS scheduling policy, a reliable distributed computing environment is required. We consider an unbiased PIRS scheduling policy on a distributed platform such as a network of workstations. We observe that including more computing resources may degrade the performance of PIRS. Simple rules are proposed to select processors for PIRS.

Leon, Linda A.; Przasnyski, Zbigniew H.

doi: 10.1177/003754979506400205pmid: N/A

For a decade spreadsheets have provided an intuitive interface and accepted environment for modelling increasingly sophisticated applications. Due to dramatic improvements in technology, end user decision makers have increasingly powerful operations research tools at their disposal, with real life successes documented in the literature. This paper presents a framework for describing linear programs with uncertainty and describes how the spreadsheet medium can be used to enhance their analysis. Procedures for analysis are discussed for the cases of prior resolvability and recourse availability and illustrated by example. A postoptimality analysis approach for the recourse problem which applies simulation to an optimization model is detailed using a spreadsheet template.

McLeod, John; McLeod, Suzette

doi: 10.1177/003754979506400206pmid: N/A