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Chai Yueting - One of the best experts on this subject based on the ideXlab platform.

  • Hybrid Multiple Ant Colonies Algorithm for Capacitated Vehicle Routing Problem
    Computer Simulation, 2007
    Co-Authors: Chai Yueting
    Abstract:

    A new multiple Ant Colonies algorithm based on sweep algorithm (SbMACA) was developed for solving the Capacitated Vehicle Routing Problem (CVRP). The SbMACA is different from other ACAs developed before mainly in two aspects. Firstly, once the Ants have constructed their solutions, each Ant’s solution might be improved by applying Sweep Algorithm which makes improvement to the solutions by exchanging the vertices between subtours. Secondly, a new Multiple Ant Colonies technique is proposed, in which multiple Ant Colonies are executed separately and simultaneously, and after all Colonies are in the state of stagnation, communication among them is carried out in order to do favor to leave the local peaks. Experiment shows that the SbMACA is able to find solutions for CVRP within 0.28% of known optimal solutions and is competitive when compared with the best Tabu Search meta-heuristics.

  • sweep based multiple Ant Colonies algorithm for capacitated vehicle routing problem
    International Conference on e-Business Engineering, 2005
    Co-Authors: Liu Zhishuo, Chai Yueting
    Abstract:

    A new meta-heuristic method of Ant colony algorithm called SbMACA is developed for solving the capacitated vehicle routing problem (CVRP). The SbMACA is different from other ACAs developed before in four aspects. First, at the beginning of constructing each new subtour during the route construction, Ant does not depart from the depot, but randomly from the vertices that have not been visited so far. Secondly, Ants in nature could not sense the pheromone until its amount is greater than certain threshold. Therefore, similarly in the SbMACA, when the Ants select the next vertex to transit, the pheromone would be neglected if its amount is less than the pre-specified threshold. Thirdly, once the Ants have constructed their solutions, each Ant's solution might be improved by applying sweep algorithm which makes improvement to the solutions by exchanging the vertices between subtours. Finally, a new multiple Ant Colonies technique is proposed, in which multiple Ant Colonies are executed separately and simultaneously, and after all Colonies are in the state of stagnation, communication among them is carried out in order to do favor to leave the local peaks. Experiment shows that the SbMACA is able to find solutions for CVRP within 0.28% of known optimal solutions and is one of the best ACA heuristics developed so far. Additionally, the performance of SbMACA is compared with that of other ACA heuristics and another meta-heuristics tabu search respectively

  • ICEBE - Sweep based multiple Ant Colonies algorithm for capacitated vehicle routing problem
    IEEE International Conference on e-Business Engineering (ICEBE'05), 2005
    Co-Authors: Liu Zhishuo, Chai Yueting
    Abstract:

    A new meta-heuristic method of Ant colony algorithm called SbMACA is developed for solving the capacitated vehicle routing problem (CVRP). The SbMACA is different from other ACAs developed before in four aspects. First, at the beginning of constructing each new subtour during the route construction, Ant does not depart from the depot, but randomly from the vertices that have not been visited so far. Secondly, Ants in nature could not sense the pheromone until its amount is greater than certain threshold. Therefore, similarly in the SbMACA, when the Ants select the next vertex to transit, the pheromone would be neglected if its amount is less than the pre-specified threshold. Thirdly, once the Ants have constructed their solutions, each Ant's solution might be improved by applying sweep algorithm which makes improvement to the solutions by exchanging the vertices between subtours. Finally, a new multiple Ant Colonies technique is proposed, in which multiple Ant Colonies are executed separately and simultaneously, and after all Colonies are in the state of stagnation, communication among them is carried out in order to do favor to leave the local peaks. Experiment shows that the SbMACA is able to find solutions for CVRP within 0.28% of known optimal solutions and is one of the best ACA heuristics developed so far. Additionally, the performance of SbMACA is compared with that of other ACA heuristics and another meta-heuristics tabu search respectively

Anna Dornhaus - One of the best experts on this subject based on the ideXlab platform.

  • Temnothorax rugatulus Ant Colonies consistently vary in nest structure across time and context.
    PloS one, 2017
    Co-Authors: Nicholas Dirienzo, Anna Dornhaus
    Abstract:

    A host of animals build architectural constructions. Such constructions frequently vary with environmental and individual/colony conditions, and their architecture directly influences behavior and fitness. The nests of Ant Colonies drive and enable many of their collective behaviors, and as such are part of their 'extended phenotype'. Since Ant Colonies have been recently shown to differ in behavior and life history strategy, we ask whether Colonies differ in another trait: the architecture of the constructions they create. We allowed Temnothorax rugatulus rock Ants, who create nests by building walls within narrow rock gaps, to repeatedly build nest walls in a fixed crevice but under two environmental conditions. We find that Colonies consistently differ in their architecture across environments and over nest building events. Colony identity explained 12-40% of the variation in nest architecture, while colony properties and environmental conditions explained 5-20%, as indicated by the condition and marginal R2 values. When their nest boxes were covered, which produced higher humidity and lower airflow, Colonies built thicker, longer, and heavier walls. Colonies also built more robust walls when they had more brood, suggesting a protective function of wall thickness. This is, to our knowledge, the first study to explicitly investigate the repeatability of nestbuilding behavior in a controlled environment. Our results suggest that Colonies may face tradeoffs, perhaps between factors such as active vs. passive nest defense, and that selection may act on individual construction rules as a mechanisms to mediate colony-level behavior.

  • Brief Announcement: Distributed Task Allocation in Ant Colonies
    2015
    Co-Authors: Anna Dornhaus, Tsvetomira Radeva, Nancy Lynch, Hsin Hao Su
    Abstract:

    A common problem in both distributed computing and insect biology is designing a model that accurately captures the behavior of a given distributed system or an Ant colony, respectively. While the challenges involved in modeling computer systems and Ant Colonies are quite different from each other, a common approach is to explore multiple variations of different models and compare the results in terms of the simplicity of the model and the quality of the results. We consider the task allocation problem as a case study and explore multiple models inspired from both distributed computing and biological experiments. We compare the models with respect to their significance in understanding real Ant behavior and also their technical relevance to distributed computing.

  • task allocation in Ant Colonies
    International Symposium on Distributed Computing, 2014
    Co-Authors: Alejandro Cornejo, Anna Dornhaus, Nancy Lynch, Radhika Nagpal
    Abstract:

    In this paper we propose a mathematical model for studying the phenomenon of division of labor in Ant Colonies. Inside this model we investigate how simple task allocation mechanisms can be used to achieve an optimal division of labor.

  • DISC - Task Allocation in Ant Colonies
    Lecture Notes in Computer Science, 2014
    Co-Authors: Alejandro Cornejo, Anna Dornhaus, Nancy Lynch, Radhika Nagpal
    Abstract:

    In this paper we propose a mathematical model for studying the phenomenon of division of labor in Ant Colonies. Inside this model we investigate how simple task allocation mechanisms can be used to achieve an optimal division of labor.

  • decision making by small and large house hunting Ant Colonies one size fits all
    Animal Behaviour, 2006
    Co-Authors: Nigel R. Franks, Anna Dornhaus, Charlotte S Best, Elizabeth L Jones
    Abstract:

    We conducted two experiments with Temnothorax albipennis Ant Colonies. In the first, we assessed their ability to select the best nest, in terms of entrance size, among an array of mediocre ones. Small and large Ant Colonies were equally adept at solving this best-of-N choice problem. However, large Colonies were faster than small ones at finding the best nest probably because they could deploy more scouts. As a result, large Colonies in nature probably find more of the available nests more quickly than small Colonies. Thus larger Colonies may have a greater tendency to split than small Colonies. Large Colonies, however, used larger quorum thresholds to make collective decisions than smaller Colonies. Higher quorum thresholds should help to reduce splitting by large Colonies. Large Colonies also used more reverse tandem runs, a process for recruitment of more active participAnts into emigrations. More reverse tandem runs may help large Colonies to reunite if they do split. In a second experiment, large and small Colonies had almost identical preferences for nests with a floor area that would ideally accommodate a fully grown colony. Thus, small Colonies behaved in a way that seemed to Anticipate their future needs, when they would have grown to fill a larger space.

Radhika Nagpal - One of the best experts on this subject based on the ideXlab platform.

Ricard V. Solé - One of the best experts on this subject based on the ideXlab platform.

  • Spatial patterns in Ant Colonies
    Proceedings of the National Academy of Sciences of the United States of America, 2002
    Co-Authors: Guy Theraulaz, Ricard V. Solé, Eric Bonabeau, Stamatios C. Nicolis, Vincent Fourcassié, Stéphane Blanco, Richard Fournier, Jean-louis Joly, Pau Fernández, Anne Grimal
    Abstract:

    The origins of large-scale spatial patterns in biology have been an importAnt source of theoretical speculation since the pioneering work by Turing (1952) on the chemical basis of morphogenesis. Knowing how these patterns emerge and their functional role is importAnt to our understanding of the evolution of biocomplexity and the role played by self organization. However, so far, conclusive evidence for local activation–long-range inhibition mechanisms in real biological systems has been elusive. Here a well-defined experimental and theoretical analysis of the pattern formation dynamics exhibited by clustering behavior in Ant Colonies is presented. These experiments and a simple mathematical model show that these Colonies do indeed use this type of mechanism. All microscopic variables have been measured and provide the first evidence, to our knowledge, for this type of self-organized behavior in complex biological systems, supporting early conjectures about its role in the organization of insect societies.

  • Self-synchronization and task fulfilment in Ant Colonies.
    Journal of theoretical biology, 2000
    Co-Authors: Jordi Delgado, Ricard V. Solé
    Abstract:

    Abstract Some authors have hypothesized that the observed self-synchronized activity in Ant Colonies provides some adaptive advAntages, and, in particular, it has been suggested that task realization may benefit from this ordered temporal pattern of behaviour (Robinson, 1992, Ann. Rev. Entomol, 37, 637–702; Hatcher et al., 1992, Naturwissenschaften, 79, 32–34). In this paper, we use a model of self-synchronized activity (the fluid neural network) to suggest that with self-synchronized patterns of activity a task may be fulfiled more effectively than with non-synchronized activity, at the same average level of activity per individual.

  • ECAL - Task Fulfilment and Temporal Patterns of Activity in Artificial Ant Colonies
    Advances in Artificial Life, 1999
    Co-Authors: Jordi Delgado, Ricard V. Solé
    Abstract:

    Since the discovery of self-synchronization of activity in Ant Colonies some authors have argued that this phenomenon lacks any adaptive significance, while others have suggested that there may be some functional behaviors related to these rhythmical patterns of activity. In this paper, we introduce a mobile automata model of task fulfilment in Ant Colonies with self-synchronized activity, and test if these synchronized patterns provide any advAntage when compared with nonsynchronized activity patterns.

J.-d. Lan Sun Luk - One of the best experts on this subject based on the ideXlab platform.

  • Cyclic scheduling following the social behavior of Ant Colonies
    IEEE International Conference on Systems Man and Cybernetics, 1
    Co-Authors: O. Fournier, P. Lopez, J.-d. Lan Sun Luk
    Abstract:

    This work presents an approach based on the behavior of Ant systems to optimize the cyclic scheduling of repetitive tasks. These tasks can represent assembling or disassembling operations which impart to the associated operating sequence an organization graphically non-linear. The scheduling optimization is obtained by coupling a simulator and heuristics based on the behavior of Ant Colonies.