Information Technology Reference
In-Depth Information
530 Advanced Artificial Intelligence
information. If the node can not finish the task because of the resource or ability
limitation, it can divide the task to some sub tasks and allocate the sub tasks to
other nodes. In this condition, the node is a manager role and provides the bids.
Every node can be a manager, bid applicant or contract member.
The traditional contract net protocol is extended to inference the negotiation
process. One of these extensions is publicizing the bid file. All the nodes can join
the bid process. This requires the communication and abundant resources.
Manager must evaluate many lot of bid files and use lot of resources. The big
load of manager is caused by the publicizing the bid files. Firstly, manger needs
the ability to inform part of the nodes. You can image that if the manager knows
the knowledge of every node, it can estimate the candidate nodes for dealing with
the sub problems. Secondly, the common bid request can be cancelled. If the
unsolved problems can use the previous methods, the manager can contact the
previous solution nodes. Once the resource can be used, the manager and the
node write down the contract. Besides, the node can self bid. In this condition,
many open bids only investigate the new tasks. The bid request is only needed
when can not find the proper bids.
The second side of contract net system extension is influencing the real
contract assignment. In the traditional protocol, manager needs to wait the node's
information after the assignment. Before the coming of the information, manager
do not know whether the node accept the contract. The node can not form
contract and build the constraint of contract after bid. Some suggestion for the
extension is build the contract constraint in an early time. For example, when a
node bid, it can provide the possible clause of accepting promise. The acceptance
is not the easy acceptant or refuse. It can hold some reference and conditions.
The biggest time limit for contract confirmation is extending farther. If there is
no confirmation for the contract in the limited time, the manager will stop the
contract. The contract process can send the information and avoid manager for
waiting long time. The managers can assignment the contract again before the
longest time interval.
14.5.3
Partial global planning
The most important trait of Partial Global PlanningPGP) approach is the
ability of each agent is determined in multi-agent system(Durfee,1991). That is
collecting the current states to reach the goals. The agents can optimize their
