1. Cooperative Meeting Scheduling among Agents based on Multiple Negotiations Toramatsu SHINTANI and Takayuki ITO Department of Intelligence and Computer Science, Nagoya Institute of Technology tora@ics.nitech.ac.jp JAPAN Motivation Distributed Meeting Scheduler Distributed scheduling Implementation Reaching a Consensus Multiple Negotiations (Persuasion Process) Preference Revision Using Private Preferences Conclusions Motivation Distributed Meeting Scheduler Distributed scheduling Implementation Reaching a Consensus Multiple Negotiations (Persuasion Process) Preference Revision Using Private Preferences Conclusions

2. Motivation

3. Background

4. Distributed Scheduling System

5. The Calendar

9. The Distributed Meeting Scheduling Request for a meeting Deciding attributes of the meeting and designing alternatives Negotiation among agents Getting a Result Quantifying the user's preference based on MAUT Negotiation among agents The Multiple Negotiations

10. The Outline of the Persuasion Process Persuasion between agent A and agent B. 1. A sends a proposal to B. 2. B tries to revise her preference. 3. If B could revise her preference, they reach an agreement. We call A "Persuader" and B "Compromiser." 1. Proposal 2. Preference revision3. Agreement A B proposal Can I accept? Agreement  1 A  2 A  3 A  2 A  1 A  3 A persuade Agent A Agent B

12. Quantifying User's Preference Using Multiple Attribute Utility Theory SizeConvenience 9:00-10:00 9:00-11:00 Scheduling a meeting Length 13:00-14:00 We can select several options with respect to f according to the application area. In our system, we select the AHP method for calculating user's utility. preference

13. Quantifying User's Preference Using AHP SizeConvenience 9:00-10:00 9:00-11:00 Scheduling a meeting Length The pairwisecomparison matrix with respect to the criterion "Convenience" 2 1/21/9 9 1/3 3 1 1 1 0.705 0.205 0.089 Weights 9:00-10:009:00-11:0013:00-14:00 9:00-10:00 9:00-11:00 13:00-14:00 AHP

14. The Preference Revision

16. The Feature of the Preference Revision The MC principle An agent should change an user's preference as minimal as possible The OC principle An agent should change an user's preference based on the preference order of alternatives In our system, a compromiser tries to adjust attribute values based on " generate and test " style. The problem is that the solution space is too huge to revise agent's preference.

17. Implementation

18. The Main Features of MiLog

20. An Example of MiLog

21. Experimental Result

22. Conclusions A new multi-agent negotiation The multiple negotiations can reflect user's individual preferences. The preference revision effectively find a solution for a compromiser in the persuasion process. The Distributed Meeting Scheduler realizing a cooperative meeting scheduling among agent improving a trade-off between "reaching a consensus" and "reflecting users' preference" in a social decision. The result shows that the multi-agent negotiation based on private preference is an effective method for a distributed meeting scheduler. The process can facilitate reaching a consensus among agents.