313 research outputs found
Two Phase Heuristic Algorithm for the University Course Timetabling Problem: The Case of University of Dar Es Salaam
University course timetabling is the problem of scheduling resources such as lecturers, courses, and rooms to a number of timeslots over a planning horizon, normally a week, while satisfying a number of problem-specific constraints. Since timetabling problems differ from one institution to another, this paper investigated the case of the University of Dar Es salaam, based on the combination of Simulated Annealing (SA), and steepest descent in a two-phase approach. Solutions have been generated which greatly outperform the manually generated ones. Furthermore, the method compares well with previous work on Tabu Search but with faster execution time and higher quality on rooms allocation. It is concluded that the approach gives good results given a careful selection of parameters.Keywords: Timetabling Problem, Simulated Annealing, Combinatorial Optimization, Steepest DescentTanz. J. Sci. Vol. 37 201
Examination timetabling at the University of Cape Town: a tabu search approach to automation
With the rise of schedules and scheduling problems, solutions proposed in literature have expanded yet the disconnect between research and reality remains. The University of Cape Town's (UCT) Examinations Office currently produces their schedules manually with software relegated to error-checking status. While they have requested automation, this study is the first attempt to integrate optimisation techniques into the examination timetabling process. Tabu search and Nelder-Mead methodologies were tested on the UCT November 2014 examination timetabling data with tabu search proving to be more effective, capable of producing feasible solutions from randomised initial solutions. To make this research more accessible, a user-friendly app was developed which showcased the optimisation techniques in a more digestible format. The app includes data cleaning specific to UCT's data management system and was presented to the UCT Examinations Office where they expressed support for further development: in its current form, the app would be used as a secondary tool after an initial solution has been manually obtained
Hybridizations within a graph based hyper-heuristic framework for university timetabling problems
A significant body of recent literature has explored various research directions in hyper-heuristics (which can be thought as heuristics to choose heuristics). In this paper, we extend our previous work to construct a unified graph-based hyper-heuristic (GHH) framework, under which a number of local search-based algorithms (as the high level heuristics) are studied to search upon sequences of low-level graph colouring heuristics. To gain an in-depth understanding on this new framework, we address some fundamental issues concerning neighbourhood structures and characteristics of the two search spaces (namely, the search spaces of the heuristics and the actual solutions). Furthermore, we investigate efficient hybridizations in GHH with local search methods and address issues concerning the exploration of the high-level search and the exploitation ability of the local search. These, to our knowledge, represent entirely novel directions in hyper-heuristics. The efficient hybrid GHH obtained competitive results compared with the best published results for both benchmark course and exam timetabling problems, demonstrating its efficiency and generality across different problem domains. Possible extensions upon this simple, yet general, GHH framework are also discussed
Operational Research in Education
Operational Research (OR) techniques have been applied, from the early stages of the discipline, to a wide variety of issues in education. At the government level, these include questions of what resources should be allocated to education as a whole and how these should be divided amongst the individual sectors of education and the institutions within the sectors. Another pertinent issue concerns the efficient operation of institutions, how to measure it, and whether resource allocation can be used to incentivise efficiency savings. Local governments, as well as being concerned with issues of resource allocation, may also need to make decisions regarding, for example, the creation and location of new institutions or closure of existing ones, as well as the day-to-day logistics of getting pupils to schools. Issues of concern for managers within schools and colleges include allocating the budgets, scheduling lessons and the assignment of students to courses. This survey provides an overview of the diverse problems faced by government, managers and consumers of education, and the OR techniques which have typically been applied in an effort to improve operations and provide solutions
Aspects of computerised timetabling
This research considers the problem of constructing high school timetables using a
computer. In the majority of high schools, termly or yearly timetables are still
being produced manually. Constructing a timetable is a hard and time consuming
task which is carried out repeatedly thus a computer program for assisting with this
problem would be of great value. This study is in three parts. First. an overall
analysis of the problem is undertaken to provide background knowledge and to
identify basic principles in the construction of a school timetable. The
characteristics of timetabling problems are identified and the necessary data for the
construction of a timetable is identified. The first part ends with the production of
a heuristic model for generating an initial solution that satisfies all the hard
constraints embodied in the curriculum requirements.
The second stage of the research is devoted to designing a heuristic model for
solving a timetable problem with hard and medium constraints. These include
constraints like the various numbers of common periods, double periods and
reducing the repeated allocation of a subject within any day. The approaches taken
are based on two recently developed techniques, namely tabu search and simulated
annealing. Both of these are used and comparisons of their efficiency are
provided. The comparison is based on the percentage fulfilment of the hard and
medium requirements.
The third part is devoted to one of the most difficult areas in timetable
construction, that is the softer requirements which are specific to particular schools
and whose satisfaction is not seen as essential. This section describes the
development of an expert system based on heuristic production rules to satisfy a
range of soft requirements. The soft requirements are studied and recorded as
rules and a heuristic solution is produced for each of the general requirements.
Different levels of rule are developed, from which the best possible solution to a
particular timetable problem is expertly produced.
Finally, possible extensions of the proposed method and its application to other
types of the timetabling problem are discussed
Evolutionary Ruin And Stochastic Recreate: A Case Study On The Exam Timetabling Problem
This paper presents a new class of intelligent systems, called Evolutionary Ruin and Stochastic Recreate, that can learn and adapt to the changing enviroment. It improves the original Ruin and Recreate principleâs performance by incorporating an Evolutionary Ruin step which implements evolution within a single solution. In the proposed approach, a cycle of Solution Decomposition, Evolutionary Ruin and Stochastic Recreate continues until stopping conditions are reached. The Solution Decomposition step first uses some domain knowledge to break a solution down into its components and assign a score to each. The Evolutionary Ruin step then applies two operators (namely Selection and Mutation) to destroy a certain fraction of the entire solution. After the above steps, an input solution becomes partial and thus the resulting partial solution needs to be repaired. The repair is carried out by using the Stochastic Recreate step to reintroduce the removed items in a specific way (somewhat stochastic in order to have a better chance to jump out of the local optima), and then ask the underlying improvement heuristic whether this move will be accepted. These three steps are executed in sequence until a specific stopping condition is reached. Therefore, optimisation is achieved by solution disruption, iterative improvement and a stochastic constructive repair process performed within. Encouraging experimental results on exam timetabling problems are reported
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