443 research outputs found

    Examination Timetable Scheduling Using Tabu Search

    Get PDF
    Examination Timetables are utilized to schedule exam-timeslots in field of Applied Science .It involved assigning times and places to suitable events by creating use of available resource. Badly designed examination timetables are not just inconvenient but proved high-priced in terms of wasting time and money. Hence, the major aim of this research is to investigate the internal method of Tabu Search in solving and improving exam-timetable problem. The research have targeted on class examination timetabling problem. Hence, Tabu search is an iterative search method. It uses a local search algorithm at every iteration to search for the finest solution in some subset of the neighborhood, which came from the finest solution obtained at the last iteration. This paper reports the powerful techniques using Tabu Search in scheduling. Examination Timetabling problem is one of the applications in scheduling. In one aspect, it deals with courses such that it executes the process time slot. These aspects are important for the examination timetabling so it can be done in a smooth way and no student can sit more than one exam in a same time slot

    Cyclic transfers in school timetabling

    Get PDF
    In this paper we propose a neighbourhood structure based on sequential/cyclic moves and a cyclic transfer algorithm for the high school timetabling problem. This method enables execution of complex moves for improving an existing solution, while dealing with the challenge of exploring the neighbourhood efficiently. An improvement graph is used in which certain negative cycles correspond to the neighbours; these cycles are explored using a recursive method. We address the problem of applying large neighbourhood structure methods on problems where the cost function is not exactly the sum of independent cost functions, as it is in the set partitioning problem. For computational experiments we use four real world data sets for high school timetabling in the Netherlands and England.We present results of the cyclic transfer algorithm with different settings on these data sets. The costs decrease by 8–28% if we use the cyclic transfers for local optimization compared to our initial solutions. The quality of the best initial solutions are comparable to the solutions found in practice by timetablers

    Cyclic transfers in school timetabling

    Get PDF
    In this paper we propose a neighbourhood structure based\ud on sequential/cyclic moves and a Cyclic Transfer algorithm for the high school timetabling problem. This method enables execution of complex moves for improving an existing solution, while dealing with the challenge of exploring the neighbourhood efficiently. An improvement graph is used in which certain negative cycles correspond to the neighbours; these cycles are explored using a recursive method. We address the problem of applying large neighbourhood structure methods on problems where the cost function is not exactly the sum of independent cost functions, as it is in the set partitioning problem. For computational experiments we use four real world datasets for high school timetabling in the Netherlands and England. We present results of the cyclic transfer algorithm with different settings on these datasets. The costs decrease by 8% to 28% if we use the cyclic transfers for local optimization compared to our initial solutions. The quality of the best initial solutions are comparable to the solutions found in practice by timetablers

    Performance Analyses of Graph Heuristics and Selected Trajectory Metaheuristics on Examination Timetable Problem

    Get PDF
    Examination timetabling problem is hard to solve due to its NP-hard nature, with a large number of constraints having to be accommodated. To deal with the problem effectually, frequently heuristics are used for constructing feasible examination timetable while meta-heuristics are applied for improving the solution quality. This paper presents the performances of graph heuristics and major trajectory metaheuristics or S-metaheuristics for addressing both capacitated and un-capacitated examination timetabling problem. For constructing the feasible solution, six graph heuristics are used. They are largest degree (LD), largest weighted degree (LWD), largest enrolment degree (LE), and three hybrid heuristic with saturation degree (SD) such as SD-LD, SD-LE, and SD-LWD. Five trajectory algorithms comprising of tabu search (TS), simulated annealing (SA), late acceptance hill climbing (LAHC), great deluge algorithm (GDA), and variable neighborhood search (VNS) are employed for improving the solution quality. Experiments have been tested on several instances of un-capacitated and capacitated benchmark datasets, which are Toronto and ITC2007 dataset respectively. Experimental results indicate that, in terms of construction of solution of datasets, hybridizing of SD produces the best initial solutions. The study also reveals that, during improvement, GDA, SA, and LAHC can produce better quality solutions compared to TS and VNS for solving both benchmark examination timetabling datasets

    Solving Examination Timetabling Problem using Partial Exam Assignment with Great Deluge Algorithm

    Get PDF
    Constructing a quality solution for the examination timetable problem is a difficult task. This paper presents a partial exam assignment approach with great deluge algorithm as the improvement mechanism in order to generate good quality timetable. In this approach, exams are ordered based on graph heuristics and only selected exams (partial exams) are scheduled first and then improved using great deluge algorithm. The entire process continues until all of the exams have been scheduled. We implement the proposed technique on the Toronto benchmark datasets. Experimental results indicate that in all problem instances, this proposed method outperforms traditional great deluge algorithm and when comparing with the state-of-the-art approaches, our approach produces competitive solution for all instances, with some cases outperform other reported result

    A Hybrid-Based Framework for Constraint Satisfaction Optimization Problems

    Get PDF
    Scheduling and timetabling are commonly faced problems in most businesses and organizations. Both of these problems fall under the domain of constraint satisfaction optimization problems (CSOP), which involves finding a solution that satisfies all hard constraints, while at the same time maximizing some weighted sum of the soft constraints. Current constraint satisfaction techniques fare poorly in terms of soft constraints satisfied, while optimization techniques cannot ensure the feasibility of the final solution. In this paper, we propose a framework for CSOP that combines both constraint satisfaction and optimization techniques into a hybrid algorithm, called the combined method (CM). We test our framework on an exam-timetabling problem (ETTP) using actual data. Our results show that CM can be expected to produce better results than using a single technique alone

    Iterated local search using an add and delete hyper- heuristic for university course timetabling

    Get PDF
    Hyper-heuristics are (meta-)heuristics that operate at a higher level to choose or generate a set of low-level (meta-)heuristics in an attempt of solve difficult optimization problems. Iterated local search (ILS) is a well-known approach for discrete optimization, combining perturbation and hill-climbing within an iterative framework. In this study, we introduce an ILS approach, strengthened by a hyper-heuristic which generates heuristics based on a fixed number of add and delete operations. The performance of the proposed hyper-heuristic is tested across two different problem domains using real world benchmark of course timetabling instances from the second International Timetabling Competition Tracks 2 and 3. The results show that mixing add and delete operations within an ILS framework yields an effective hyper-heuristic approach
    • 

    corecore