• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Heuristiky pro dynamické úlohy obchodního cestujícího / Heuristic for dynamic traveling salesman problem

Belfín, Martin January 2009 (has links)
This thesis consists of two parts: text and programming part. It is divided into seven chapters. Its main goal is to compare heuristics for dynamic traveling salesman problem in a few perspectives. The text part of this thesis theoretically describes heuristic methods and in the programming part are wake up to life via VBA in MS Excel. The results of computational experiments on these heuristic methods are presented in the last chapter. In the first part, the traveling salesman problem and its solution are being described. Characteristic of the modification in a form of dynamic traveling salesman problem follow. Next chapter presents the programming solution chosen heuristics. The final chapter presents experimental results obtain with programmed heuristics.
2

Evaluating pheromone intensities and 2-opt local search for the Ant System applied to the Dynamic Travelling Salesman Problem / Utvärdering av feromonintensiteter och 2-opt lokalsökning i Ant System för det dynamiska handelsresandeproblemet

Svensson, Erik R., Lagerqvist, Klas January 2017 (has links)
Ant Colony Optimization (ACO) algorithms have been successful in solving a wide variety of NPhard optimization problems. The Traveling Salesman Problem (TSP) has served as a benchmarking problem for many novel ACO algorithms. The slightly harder Dynamic Traveling Salesman Problem (DTSP) is more realistic in the sense that real-time changes happen in the graph belonging to a TSP instance. This thesis studied the original ACO algorithm: the Ant System, and how the amount of pheromone deposited by the ants within the algorithm affected the performance when solving both TSP and DTSP problems. Additionally, 2-opt local search was added to the algorithm, to see how it impacted the performance. We found that when the ants deposited a greater amount of pheromone, the performance for TSP increased, while the performance for DTSP decreased. We concluded that the Ant System in its original form is unsuitable for solving the DTSP. 2-opt local search improved the performance in all instances. / Ant Colony Optimization-algoritmer (ACO) har visat sig vara bra på att lösa många olika NP-svåra optimeringsproblem. För att mäta prestandan för nya ACO-algoritmer har i många fall Handelsresandeproblemet (eng. TSP) använts. Den dynamiska varianten av TSP (eng. DTSP), är ett något svårare problem då förändringar i grafen kan ske i realtid. Denna uppsats utredde hur olika mängder feromon som avges av myrorna inuti algoritmen Ant System, påverkade prestandan för både TSPoch DTSP-instanser. Utöver detta studerades hur den lokala sökningsheuristiken 2-opt påverkade prestandan. Resultaten visade att om myrorna tilläts släppa mer feromoner, ökade prestantan för TSP, men minskade för DTSP. Därav drog vi slutsatsen att algoritmen Ant System i sin ursprungliga form ej är lämplig för att lösa DTSP. Den lokala söknigsheuristiken 2-opt förbättrade prestandan i alla tester.

Page generated in 0.0749 seconds