The MIIS Eprints Archive: No conditions. Results ordered -Date Deposited. 2021-08-05T15:43:23ZEPrintshttp://miis.maths.ox.ac.uk/images/sitelogo.gifhttp://miis.maths.ox.ac.uk/miis/2007-02-15Z2015-05-29T19:47:10Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/90This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/902007-02-15ZMathematical Techniques for Neuromuscular AnalysisIn the central nervous system, alpha-motor neurons play a key role in the chain that results in muscles producing force. A new non-invasive technique to measure the electrical activity involved with force production called High Density Surface Electromyography (HDsEMG) has been proven to be effective in providing novel clinical information on the way alpha-motor neurons control the muscles. This is important for the monitoring of the progression of certain neuromuscular disorders such as polio. The result of HDsEMG is, however, very difficult to interpret. In this paper we augment the usefulness of HDsEMG with automated mathematical techniques to aid the Motor Unit Number Estimation (MUNE) problem. Also, we create a stochastic model for the firing behavior of an alpha-motor neuron.JF WilliamsGeertje HekAlistair VardyVivi RottschäferJan Bouwe van den BergJoost Hulshof2007-02-05Z2015-05-29T19:47:04Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/83This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/832007-02-05ZThe mathematical modelling of cooling and rewarming patients during cardiac surgeryThe process of cooling bodies, by the use of a heart lung machine (HLM), is utilised in a number of surgical procedures primarily to reduce the metabolic rate of the organs and hence their consumption of oxygen. On completion of surgery the blood is rewarmed by the HLM. A major consequence at the end of this process is afterdrop: a rapid decrease in the core organ temperature as a result of spatial temperature differences between the core organs and remainder of the body, which can lead to post-operative complications. This report details two mathematical models developed to understand heat transfer processes between the core organs, rectal region and peripheral body parts (primarily skin, muscle and fat). A one compartment spatially independent model, describing the temperature distribution of a single tissue type through which blood perfuses, shows that temperature dependent perfusion reproduces the observed differences in blood and tissue temperatures, whilst temperature independent perfusion does not. The model is extended to account for heat transfer between the blood pool (core), rectal regions and periphery. This three compartmental model is able to qualitatively reproduce the observed temperature differences in the three regions. Analysis of the model shows that a period of constant warming at the end of the rewarming period has a positive effect in reducing afterdrop.Marcus TindallMark PeletierJoyce AitchisonSimon van MourikNatascha Severens2007-02-05Z2015-05-29T19:47:05Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/84This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/842007-02-05ZPlanning drinking water for airplanesThe management of the Dutch national airline company KLM intends to bring a sufficient amount of water on board of all flights to fulfill customer’s demand. On the other hand, the surplus of water after a flight should be kept to a minimum to reduce fuel costs. The service to passengers is measured with a service level. The objective of this research is to develop models, which can be used to minimize the amount of water on board of flights such that a predefined service level is met. The difficulty that has to be overcome is the fact that most of the available data of water consumption on flights are rounded off to the nearest eighth of the water tank. For wide-body aircrafts this rounding may correspond to about two hundred litres of water. Part of the problem was also to define a good service level. The use of a service level as a model parameter would give KLM a better control of the water surplus. The available data have been analyzed to examine which aspects we had to take into consideration. Next, a general framework has been developed in which the service level has been defined as a Quality of Service for each flight: The probability that a sufficient amount of water is available on a given flight leg. Three approaches will be proposed to find a probability distribution function for the total water consumption on a flight. The first approach tries to fit a distribution for the water consumption based on the available data, without any assumptions on the underlying shape of the distribution. The second approach assumes normality for the total water consumption on a flight and the third approach uses a binomial distribution. All methods are validated and numerically illustrated. We recommend KLM to use the second approach, where the first approach can be used to determine an upper bound on the water level.Marco BijvankMenno DobberMaarten SoomerQuentin BottonEléonore de le CourtJean-Christophe Van den SchrieckMoïra de VironMyriam Cisneros-MolinaKlaus SchmitzRemco van der HofstadEllen JochemszTim MusscheMartin SummerMaroescha HoekstraJeroen MulderMark Paelinck2007-02-05Z2015-05-29T19:47:07Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/85This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/852007-02-05ZSelection effects in forensic scienceIn this report we consider the following question: does a forensic expert need to know exactly how the evidential material was selected? We set up a few simple models of situations in which the way evidence is selected may influence its value in court. Although reality is far from a probabilistic model, and one should be very careful when applying theoretical results to real life situations, we believe that the results in our models indicate how the selection of evidence affects its value. We conclude that selection effects in forensic science can be quite important, and that from a statistical point of view, improvements can be made to court room practice.Geert Jan FranxYves van GennipPeter HochsMisja NuyensLuigi PallaCorrie QuantPieter Trapman2007-02-05Z2015-05-29T19:47:08Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/86This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/862007-02-05ZOptimal weighing schemesWe study the problem of determining the masses of a set of weights, given one standard weight, based on comparing two disjoint subsets of those weights with approximately equal mass. The question is how to choose a weighing scheme, i.e., different pairs of subsets, such that the masses can be determined as accurately as possible within a given number of measurements. In this paper we discuss a new way of using the so-called STS method of comparing two approximately equal masses, and we will give optimal weighing schemes which turn out to outperform schemes that are currently used by national metrology institutes.Sandjai BhulaiThomas BreuerEric CatorFieke Dekkers2007-02-05Z2015-05-29T19:47:09Zhttp://miis.maths.ox.ac.uk/miis/id/eprint/87This item is in the repository with the URL: http://miis.maths.ox.ac.uk/miis/id/eprint/872007-02-05ZPartitioning a call graphSplitting a large software system into smaller and more manageable units has become an important problem for many organizations. The basic structure of a software system is given by a directed graph with vertices representing the programs of the system and arcs representing calls from one program to another. Generating a good partitioning into smaller modules becomes a minimization problem for the number of programs being called by external programs. First, we formulate an equivalent integer linear programming problem with 0–1 variables. theoretically, with this approach the problem can be solved to optimality, but this becomes very costly with increasing size of the software system. Second, we formulate the problem as a hypergraph partitioning problem. This is a heuristic method using a multilevel strategy, but it turns out to be very fast and to deliver solutions that are close to optimal.Rob H. BisselingJarosław ByrkaSelin Cerav-ErbasNebojša GvozdenovícMathias LorenzRudi PendavinghColin ReevesMatthias RögerArie Verhoeven