Matches in SemOpenAlex for { <https://semopenalex.org/work/W2461809660> ?p ?o ?g. }
Showing items 1 to 86 of
86
with 100 items per page.
- W2461809660 abstract "Scheduling problems are central in combinatorial optimization, and there exists a huge literature describing both problems and algorithms. Master surgery scheduling (MSS), where one must assign surgery teams in hospitals to different rooms at different times, is a specialization of the assignment problem, which can be solved using mixed integer programming (MIP). If not all parameters to an optimization problem are known beforehand, we may use robust optimization to find solutions which are both feasible and good, even if the parameters are not as expected. In particular, we assume such parameters to vary in a given set of possible ”realizations”. The more realistic assumptions, the better solutions. In this thesis we model MSS with the aim of minimizing the expected queue lengths in hospitals. The model is made robust by considering the demand to be uncertain, but belonging to a simple polytope. It can be modeled as a bilevel program. The master program looks for feasible schedules minimizing queue lengths, while the slave program looks for feasible demands maximizing queue lenghts. In order to solve this bilevel program, we use an iterative cutting plane approach. We find a solution with the best possible behaviour for the worst case parameters, by splitting the problem in two. In particular, we implemented the so-called ”implementor/adversary” scheme (I-A), recently proposed by Bienstock in the context of portfolio optimization (see [7, 8]). The implementor finds an optimum schedule with respect to a restricted set of feasible parameter vectors. The adversary finds a new vector (not included in the restricted set) which maximizes queues with respect to the current schedule. The new vector is included in the restricted set and the method is iterated. When the adversary is not able to find a new parameter realization which is worsening the value of the current schedule, we are finished. In our experiments on realistic instances we need at most a few hundred of iteration before convergence is reached. For comparison, we also make a non-robust model of MSS as a reference solution, where we only consider a single demand vector. Testing shows that I-A is indeed a very effective algorithm, solving large problem instances in reasonable time. Moreover, the solutions were in general found to be considerably better than the non-robust reference solution, even in cases where the demand did not belong to the polytope we assumed. The algorithm also gives us good intermediate solutions with provable bounds on optimality, which can be used even if convergence is not reached. We believe I-A both offers more flexibility and yields better results compared to the other robust approaches, when applied to the right problems, MSS only being one of these." @default.
- W2461809660 created "2016-07-22" @default.
- W2461809660 creator A5060624201 @default.
- W2461809660 date "2010-01-01" @default.
- W2461809660 modified "2023-09-27" @default.
- W2461809660 title "A cutting plane algorithm for robust scheduling problems in medicine" @default.
- W2461809660 cites W1569990960 @default.
- W2461809660 cites W1571051474 @default.
- W2461809660 cites W1968143987 @default.
- W2461809660 cites W1975320652 @default.
- W2461809660 cites W1975387421 @default.
- W2461809660 cites W1995285162 @default.
- W2461809660 cites W2008772536 @default.
- W2461809660 cites W2035535059 @default.
- W2461809660 cites W2080463510 @default.
- W2461809660 cites W2089105401 @default.
- W2461809660 cites W2104142351 @default.
- W2461809660 cites W2131039757 @default.
- W2461809660 cites W213509098 @default.
- W2461809660 cites W2152575352 @default.
- W2461809660 cites W2164895118 @default.
- W2461809660 cites W2165775468 @default.
- W2461809660 cites W2181550471 @default.
- W2461809660 cites W2611147814 @default.
- W2461809660 cites W2752885492 @default.
- W2461809660 cites W2913566234 @default.
- W2461809660 cites W3145128584 @default.
- W2461809660 hasPublicationYear "2010" @default.
- W2461809660 type Work @default.
- W2461809660 sameAs 2461809660 @default.
- W2461809660 citedByCount "1" @default.
- W2461809660 crossrefType "dissertation" @default.
- W2461809660 hasAuthorship W2461809660A5060624201 @default.
- W2461809660 hasConcept C109839438 @default.
- W2461809660 hasConcept C111919701 @default.
- W2461809660 hasConcept C126255220 @default.
- W2461809660 hasConcept C137836250 @default.
- W2461809660 hasConcept C160403385 @default.
- W2461809660 hasConcept C193254401 @default.
- W2461809660 hasConcept C199360897 @default.
- W2461809660 hasConcept C206729178 @default.
- W2461809660 hasConcept C33923547 @default.
- W2461809660 hasConcept C41008148 @default.
- W2461809660 hasConcept C41045048 @default.
- W2461809660 hasConcept C56086750 @default.
- W2461809660 hasConcept C68387754 @default.
- W2461809660 hasConceptScore W2461809660C109839438 @default.
- W2461809660 hasConceptScore W2461809660C111919701 @default.
- W2461809660 hasConceptScore W2461809660C126255220 @default.
- W2461809660 hasConceptScore W2461809660C137836250 @default.
- W2461809660 hasConceptScore W2461809660C160403385 @default.
- W2461809660 hasConceptScore W2461809660C193254401 @default.
- W2461809660 hasConceptScore W2461809660C199360897 @default.
- W2461809660 hasConceptScore W2461809660C206729178 @default.
- W2461809660 hasConceptScore W2461809660C33923547 @default.
- W2461809660 hasConceptScore W2461809660C41008148 @default.
- W2461809660 hasConceptScore W2461809660C41045048 @default.
- W2461809660 hasConceptScore W2461809660C56086750 @default.
- W2461809660 hasConceptScore W2461809660C68387754 @default.
- W2461809660 hasLocation W24618096601 @default.
- W2461809660 hasOpenAccess W2461809660 @default.
- W2461809660 hasPrimaryLocation W24618096601 @default.
- W2461809660 hasRelatedWork W107659520 @default.
- W2461809660 hasRelatedWork W1231304043 @default.
- W2461809660 hasRelatedWork W1546445757 @default.
- W2461809660 hasRelatedWork W1550594240 @default.
- W2461809660 hasRelatedWork W1576802720 @default.
- W2461809660 hasRelatedWork W2055531560 @default.
- W2461809660 hasRelatedWork W2257895904 @default.
- W2461809660 hasRelatedWork W2320679437 @default.
- W2461809660 hasRelatedWork W2373985450 @default.
- W2461809660 hasRelatedWork W2555400983 @default.
- W2461809660 hasRelatedWork W2805284813 @default.
- W2461809660 hasRelatedWork W2891523970 @default.
- W2461809660 hasRelatedWork W2894117319 @default.
- W2461809660 hasRelatedWork W2915625821 @default.
- W2461809660 hasRelatedWork W3006188715 @default.
- W2461809660 hasRelatedWork W3106209261 @default.
- W2461809660 hasRelatedWork W3128279795 @default.
- W2461809660 hasRelatedWork W3135995183 @default.
- W2461809660 hasRelatedWork W3159497191 @default.
- W2461809660 hasRelatedWork W657346175 @default.
- W2461809660 isParatext "false" @default.
- W2461809660 isRetracted "false" @default.
- W2461809660 magId "2461809660" @default.
- W2461809660 workType "dissertation" @default.