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Parallel algorithms of timetable generation
Blekinge Institute of Technology, School of Computing.
2013 (English)Independent thesis Advanced level (degree of Master (Two Years))Student thesisAlternative title
Parallella algoritmer för att generera scheman. (Swedish)
Abstract [en]

Context: Most of the problem of generating timetable for a school belongs to the class of NP-hard problems. Complexity and practical value makes this kind of problem interesting for parallel computing. Objectives: This paper focuses on Class-Teacher problem with weighted time slots and proofs that it is NP-complete problem. Branch and bound scheme and two approaches to distribute the simulated annealing are proposed. Empirical evaluation of described methods is conducted in an elementary school computer laboratory. Methods: Simulated annealing implementation described in literature are adapted for the problem, and prepared for execution in distributed systems. Empirical evaluation is conducted with the real data from Polish elementary school. Results: Proposed branch and bound scheme scales nearly logarithmically with the number of nodes in computing cluster. Proposed parallel simulated annealing models tends to increase solution quality. Conclusions: Despite a significant increase in computing power, computer laboratories are still unprepared for heavy computation. Proposed branch and bound method is infeasible with the real instances. Parallel Moves approach tends to provide better solution at the beginning of execution, but the Multiple Independent Runs approach outruns it after some time.

Abstract [sv]

Sammanhang: De flesta problem med att generera scheman för en skola tillhör klassen av NP-svårt problemen. Komplexitet och praktiskt värde gör att den här typen av problemen forskas med särskild uppmärksamhet på en parallell bearbetning.   Syfte: Detta dokument fokusarar på Klass-Lärare problem med vikter för enskilda tidsluckor och på att visa var ett NP-svårt problem är fullständigt. Branch and bound scheman och två metoder för att distribuera en simulerad glödgning algoritm presenterades. En empirisk analys av beskrivna metoder gjordes i datorlaboratorium i en grundskola. Metod: Implementering av en simulerad glödgning algoritm som beskrivs i litteraturen blev anpassad till ett utvalt problem och distribuerade system. Empirisk utvärdering genomförs med verkliga data från polska grundskolan Resultat: Föreslagit Branch and bound system graderar nästan logaritmiskt antal noder i ett datorkluster. Den simulerade glödgning algoritmen som föreslagits förbättrar lösningarnas kvalitet. Slutsatser: Trots att en betydande ökning med beräkningskraft är inte datasalar i skolor anpassad till avancerade beräkningar. Användning av den Branch and Bound föreslagna metoden till praktiska problem är omöjlig i praktiken. En annan föreslagen metod Parallel Moves ger bättre resultat i början av utförandet men Multiple Independent Runs hittar bättre lösningar efter en viss tid.

Place, publisher, year, edition, pages
2013. , p. 55
Keywords [en]
school timetable, branch and bound simulated annealing, parallel algorithms
National Category
Computer Sciences
Identifiers
URN: urn:nbn:se:bth-6083Local ID: oai:bth.se:arkivexDF140DC5FED86BCCC1257C4300520872OAI: oai:DiVA.org:bth-6083DiVA, id: diva2:833503
Uppsok
Technology
Supervisors
Available from: 2015-04-22 Created: 2013-12-16 Last updated: 2018-01-11Bibliographically approved

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