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dc.contributor.advisorTjelmeland, Håkonnb_NO
dc.contributor.authorLilleborge, Marienb_NO
dc.date.accessioned2014-12-19T13:59:52Z
dc.date.available2014-12-19T13:59:52Z
dc.date.created2012-11-08nb_NO
dc.date.issued2012nb_NO
dc.identifier566327nb_NO
dc.identifierntnudaim:8128nb_NO
dc.identifier.urihttp://hdl.handle.net/11250/259044
dc.description.abstractWe present a method for finding the optimal decision on Random Variables in a graphical model. Upper and lower bounds on the exact value for each decision are used to reduce the complexity of the algorithm, while we still ensure that the decision chosen actually represents the exact optimal choice. Since the highest lower bound value is also a lower bound on the value of the optimal decision, we rule out any candidate with an upper bound of lower value than the highest lower bound. By this strategy, we try to reduce the number of candidates to a number we can afford to do exact calculations on.We generate five Bayesian Networks with corresponding value functions, and apply our strategy to these. The bounds on the values are obtained by use of an available computer program, where the complexity is controlled by an input constant. We study the number of decisions accepted for different values of this input constant. From the first Network, we learn that the bounds does not work well unless we split the calculations into parts for different groups of the nodes. We observe that this splitting works well on the next three Networks, while the last Network illustrates how the method fails when we add more edges to the graph. We realize that our improved strategy is successful on sparse graphs, while the method is unsuccessful when we increase the density of edges among the nodes.nb_NO
dc.languageengnb_NO
dc.publisherInstitutt for matematiske fagnb_NO
dc.subjectntnudaim:8128no_NO
dc.subjectMTFYMA fysikk og matematikkno_NO
dc.subjectIndustriell matematikkno_NO
dc.titleEfficient Calculation of Optimal Decisions in Graphical Modelsnb_NO
dc.typeMaster thesisnb_NO
dc.source.pagenumber137nb_NO
dc.contributor.departmentNorges teknisk-naturvitenskapelige universitet, Fakultet for informasjonsteknologi, matematikk og elektroteknikk, Institutt for matematiske fagnb_NO


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