1. FRE 2672 TFG Self-Organization - 01/07/2004 Engineering Self-Organization in MAS Complex adaptive systems using situated MAS Salima Hassas LIRIS-CNRS Lyon I University, France

2. TFG Self-Organization - 01/07/2004 2 Outline Introduction Self-organizing Computing systems as self- organizing Situated MAS  Coupling to the environment  Co-evolution of social and spatial organizations  A complex adaptive system perspective Some illustrations Conclusion

3. TFG Self-Organization - 01/07/2004 3 Introduction Evolution of computing systems: High complexity  Complex environments, sophisticated applications  Complex data and usages/practices;  Emergence of new needs, new practices, … Computing system: a system open on its environment Complexity of the environment: distributed, dynamic, evolving, uncertain, …

4. TFG Self-Organization - 01/07/2004 4 Examples Evolution of the Internet and the Web  A complex dynamic network, exhibiting a self-organizing character… Evolution of Software Engineering  Awareness of dynamic changes of the environment  Design at run-time User more and more present  User centered systems  Capture usages/practices through system use

5. TFG Self-Organization - 01/07/2004 5 Issue How to design computing systems exhibiting intelligence while embodied in their environment, considered at its widest meaning? Widest meaning: physical as well as conceptual environment

6. TFG Self-Organization - 01/07/2004 6 Issue Environment is thus put at the heart of the engineering of the computing system  Conceptual environment related to uses (practices) Place of materialization of uses (ex: Virtual communities)  Physical environment Place of materialization (embodiment) of the computing system =>a complex network of resources Place of inscription of traces of uses related to actions and interactions => Ex: web/Internet topology expresses usages

7. TFG Self-Organization - 01/07/2004 7 Approach The system is considered through its coupling with its environment A double articulation:  Physical articulation : Structural Coupling  Conceptual articulation : Behavioral Coupling Retroactive effects of one coupling on another  Organizational articulation

8. TFG Self-Organization - 01/07/2004 8 Implications on a MAS Using Situated MAS to implement this kind of computing systems (complex systems aware of their environment) The MAS is subject to the same coupling with its environment:  Structural Coupling : Physical articulation  Spatial organization of the MAS / physical environment  Behavioral Coupling : Conceptual articulation  Social organization of the MAS / conceptual environment  Retroactive effects of one coupling on another  Co-evolution of spatial and social organizations of the MAS

9. TFG Self-Organization - 01/07/2004 9 Implications on a MAS The design of the situated MAS must address  its spatial organization  its social organization  And the co-evolution of both organizations through the MAS dynamics Self-organization is mandatory  The eternal ants foraging exampleants foraging  Emergent Structures : shortest paths from nest to food source Physical materialization of the spatial organization  Emergent behavior : self-catalytic frequentation of paths Conceptual materialization of the social organization  Self-organization is the mechanism which allows co-evolution of social and spatial organization Need for a “glue” between both organizations : stigmergy mechanism

10. TFG Self-Organization - 01/07/2004 10 Our vision The computing system as a Complex Adaptive System  A set of interconnected components (agents), strongly interacting with one another at different levels :  Micro level: retroactive interactions between agents (local behaviors)  Macro level: emerging structure and organization of the system (global behaviors)  System Dynamics : maintaining the system organization  Non linear dynamic (retroactions and emergences)  Coupling to the environment: autopoïetic vision  Co-evolution “structures-their generating processes”: reflective loop  Co-evolution of “spatial organization-social organization” in MAS

11. TFG Self-Organization - 01/07/2004 11 Positioning Self-Organizing Computing systems Complex Adaptive Systems Non Linear Dynamic Systems Situated Multi-Agents General System Theory Cybernetics Chaos Theory, statistical mechanics,.. Artificial life Embodied intelligence Nature-inspired computing

12. TFG Self-Organization - 01/07/2004 12 Propositions

13. TFG Self-Organization - 01/07/2004 13 A Guiding framework A framework for developing self-organizing computing systems:  Physical materialization of the environment and its spatial representation A complex dynamic network of resources: importance of topology  Embodied Intelligence using situated agents Population of situated agents embodied in a physical (spatial) environment ==> incarnation of the computing system  Stigmergy Spatial structure for coding control and meta-control information case of the electronic pheromone  Individual behaviors Correlation Strategy: balancing exploitation (reinforcement) /exploration (diversity)

14. TFG Self-Organization - 01/07/2004 14 Topology Scale Free Networks and « small world » property  Scale free  Small number of highly connected nodes, distributed randomly  High number of nodes weakly connected Small world  Small average length between any couple of nodes Topology of networks produced by human activities / nature (exhibiting self-organization..)

15. TFG Self-Organization - 01/07/2004 15 Illustration A computing ecosystem on the web: WACO system  A multi-agents system : An ecosystem composed of Web Ants (mobile agents), mapped on the web Using a social insects paradigm (stigmergy) Combining foraging and collective sorting Specialization/population regulation following the web content  Dynamics of population: Energy mechanism (order/disorder of web content) (IEEE Swarm Intelligence 03 publication)

16. TFG Self-Organization - 01/07/2004 16 Illustration Experiment1 : Disorder decreasing  Disorder decreases while new documents are created  Disorder=number of scattered documents  Negative value of disorder : multiple clustering of a same document Scattered documents are those created (order emergence)

17. TFG Self-Organization - 01/07/2004 17 Illustration Experiment 2 : Clusters forming  Effectiveness of clustering  Size of clusters increases regularly  Sudden (small) decrease of mean clusters sizes near time 80000 Order emergence disturbed by new creations Scattered documents are those created

18. TFG Self-Organization - 01/07/2004 18 Illustration Experiment3: Energy evolution Energy evolution follows the disorder evolution  Decrease near time 80000  => order emergence  Decrease near time 100000  => new clustering operation: specialists creation order emergence Specialists creation

19. TFG Self-Organization - 01/07/2004 19 Illustration Energy of specialized agents  Specialists energy increase during clusters forming  Near order emergence (near time 80000) energy = 0  Sudden increasing near time 100000, new clusters apparition

20. TFG Self-Organization - 01/07/2004 20 Illustration ECoNET  Dynamic multi-criteria balancing on a network of processors  Problem: On a network of processors, processes must find dynamically a spatial repartition allowing the satisfaction of the 4 following criteria : Balancing the average of the perceived load Spatial clustering of processes belonging to the same application (sharing of same data, resources) Spatial clustering of processes belonging to highly communicating different applications (minimize communications delays) Spatial repulsion of concurrent processes accessing the same resources (resources access conflicts) Note Environment is subject to perturbations and criteria may evolve during time..

21. TFG Self-Organization - 01/07/2004 21 Conclusion Towards a methodolgy of self-organizing computing systems  Environment : A central point for the system  Situated MAS paradigm: incarnation of the computing system  The MAS is subject to the same coupling with respect to its environment Deployment of the MAS in its physical environment : spatial organization Maintaining the spatial organization through the social organization of the MAS Retro-active effects of one organization on the other

22. TFG Self-Organization - 01/07/2004 22 Conclusion Necessary to study :  Relation between spatial organization and the environment topology (and their retro-active effects)  Reflective coupling: structure-processes (autopoïesis)  Relation between spatial organization and social organization (and their retro-active effects)  Structure-environment coupling (self-organization)  Reflective effects between the two coupling  Co-evolution of both (emergent) organizations and the environment topology

23. TFG Self-Organization - 01/07/2004 23 Thank you :))