Combining Information from Multiple Internet Sources

Listing 3.2.3 presents the pseudo code for the main process of the Auction method.
Input: Map containing URL rankings.
Output: 10 URLs.
BEGIN
1. repeat until there are 10 URLs in answer list
2. repeat until one agent remains
3. find highest ranked URLs for all agents and pair them like
( i) ( i)
( A , U )
4. calculate costs for each agent:
cost
( i )
( A )
i=∑ =
1, i=
j
Listing 3.2.3 Auction method main algorithm
Following activity diagram presents the Auction method workflow. Like in the previous case
all objects in the process are shown on this diagram so that it can be easily seen who is responsible
for certain parts of the process.
=
i
m
rank
( i) ( i)
( i) ( j )
( A , U ) − rank A , U
10
( )
where U ( i)
( i) ( i)
is URL from pair ( A , U ) (highest ranked URL for
agent A ( i ) and U ( j ) is a highest ranked URL for agent A
( j )
5. find agent with highest cost – he is a loser
• it may happen that all agents have the same costs – if it
occurs twice the agent which is assigned the URL initially
ranked as the lowest is considered a loser and thus removed
from further negotiation, if it so go to 7.
6. if the agent is a loser twice in a row remove him from further
auction
7. update URL rankings for all agents with following values:
( i) ( i)
( i) ( i)
( i)
rank( A , U ) = rank( A , U ) − cost( A )
( i) ( i)
where ( A , U ) is the pair found at the beginning; at this
point the winning URL can be changed
8. add URL to answer list
9. remove the URL from further evaluation
10. go to 2
END
31