934 research outputs found

    A general framework of multi-population methods with clustering in undetectable dynamic environments

    Get PDF
    Copyright @ 2011 IEEETo solve dynamic optimization problems, multiple population methods are used to enhance the population diversity for an algorithm with the aim of maintaining multiple populations in different sub-areas in the fitness landscape. Many experimental studies have shown that locating and tracking multiple relatively good optima rather than a single global optimum is an effective idea in dynamic environments. However, several challenges need to be addressed when multi-population methods are applied, e.g., how to create multiple populations, how to maintain them in different sub-areas, and how to deal with the situation where changes can not be detected or predicted. To address these issues, this paper investigates a hierarchical clustering method to locate and track multiple optima for dynamic optimization problems. To deal with undetectable dynamic environments, this paper applies the random immigrants method without change detection based on a mechanism that can automatically reduce redundant individuals in the search space throughout the run. These methods are implemented into several research areas, including particle swarm optimization, genetic algorithm, and differential evolution. An experimental study is conducted based on the moving peaks benchmark to test the performance with several other algorithms from the literature. The experimental results show the efficiency of the clustering method for locating and tracking multiple optima in comparison with other algorithms based on multi-population methods on the moving peaks benchmark

    Solving Multiple Timetabling Problems at Danish High Schools

    Get PDF

    Automated university lecture timetable using Heuristic Approach

    Get PDF
    There are different approaches used in automating course timetabling problem in tertiary institution. This paper present a combination of genetic algorithm (GA) and simulated annealing (SA) to have a heuristic approach (HA) for solving course timetabling problem in Federal University Wukari (FUW). The heuristic approach was implemented considering the soft and hard constraints and the survival for the fittest. The period and space complexity was observed. This helps in matching the number of rooms with the number of courses. Keywords: Heuristic approach (HA), Genetic algorithm (GA), Course Timetabling, Space Complexity

    Comparing several heuristics for a packing problem

    Full text link
    Packing problems are in general NP-hard, even for simple cases. Since now there are no highly efficient algorithms available for solving packing problems. The two-dimensional bin packing problem is about packing all given rectangular items, into a minimum size rectangular bin, without overlapping. The restriction is that the items cannot be rotated. The current paper is comparing a greedy algorithm with a hybrid genetic algorithm in order to see which technique is better for the given problem. The algorithms are tested on different sizes data.Comment: 5 figures, 2 tables; accepted: International Journal of Advanced Intelligence Paradigm

    Companion PASS Program

    Get PDF
    At the end of each quarter the students of Cal Poly prepare to sign up for their classes for next quarter. This process is more difficult for seniors who must meet very specific requirements in order to graduate on time. Students can spend hours trying to find the “perfect schedule”, that one schedule that fits their personal schedule and their graduation requirements, while not over taxing themselves during that quarter by having too much class work. This Cal Poly explores the creation and implementation of an extra scheduling tool to address the weaknesses of the current scheduling system, PASS, and help students reduce the amount of time spent looking for that one “perfect schedule”. The companion program makes use of MS Access and MS Excel, both common Office Programs, to create a system that offers more optimization options in choosing what classes a student would like to take for the next quarter. Working with several queries in Access and then changing those queries into constraints for Excel solver this Senior Project was able to create an ‘alpha’ level companion program that is function, but not fully tested or edited for ease of use by senior level industrial engineering students at Cal Poly

    The Optimum Combination Of Local Searches For Genetic Operators In Memetic Algorithm For The Space Allocation Problem [QA9.58. S624 2008 f rb].

    Get PDF
    Dalam tesis ini, kami membuat penyelidikan mengenai pengagihan ruang di universiti. Kajian ini memfokus kepada pengagihan ruang dalam penyediaan jadual waktu. This thesis investigates the university space allocation problem, which focuses on the distribution of events among the available venues, without violating any hard constraints while satisfying as many soft constraints as possible and ensure optimum space utilization

    Hypercube FrameWork for ACO applied to timetabling

    Get PDF
    We present a resolution technique of the University course Timetabling problem (UCTP), this technique is based in the implementation of Hypercube framework using the Max-Min Ant System. We presented the structure of the problem and the design of resolution using this framework. A simplification of the UCTP problem is used, involving three types of hard restrictions and three types of soft restrictions. We solve experimental instances and competition instances the results are presented of comparative form to other techniques. We presented an appropriate construction graph and pheromone matrix representation. A representative instance is solved in addition to the schedules of the school of Computer science engineering of the Catholic University of Valparaiso. The results obtained for this instance appear. Finally the conclusions are given.IFIP International Conference on Artificial Intelligence in Theory and Practice - Evolutionary ComputationRed de Universidades con Carreras en Informática (RedUNCI

    Courses timetabling based on hill climbing algorithm

    Get PDF
    In addition to its monotonous nature and excessive time requirements, the manual school timetable scheduling often leads to more than one class being assigned to the same instructor, or more than one instructor being assigned to the same classroom during the same slot time, or even leads to exercise in intentional partialities in favor of a particular group of instructors. In this paper, an automated school timetable scheduling is presented to help overcome the traditional conflicts inherent in the manual scheduling approach. In this approach, hill climbing algorithms have been modified to transact hard and soft constraints. Soft constraints are not easy to be satisfied typically, but hard constraints are obligated. The implementation of this technique has been successfully experimented in different schools with various kinds of side constraints. Results show that the initial solution can be improved by 72% towards the optimal solution within the first 5 seconds and by 50% from the second iteration while the optimal solution will be achieved after 15 iterations ensuring that more than 50% of scientific courses will take place in the early slots time while more than 50% of non-scientific courses will take place during the later time's slots
    corecore