Evidence combination for a large number of sources
  The theory of belief functions is an effective tool to deal with the multiple
uncertain information. In recent years, many evidence combination rules have
been proposed in this framework, such as the conjunctive rule, the cautious
rule, the PCR (Proportional Conflict Redistribution) rules and so on. These
rules can be adopted for different types of sources. However, most of these
rules are not applicable when the number of sources is large. This is due to
either the complexity or the existence of an absorbing element (such as the
total conflict mass function for the conjunctive-based rules when applied on
unreliable evidence). In this paper, based on the assumption that the majority
of sources are reliable, a combination rule for a large number of sources,
named LNS (stands for Large Number of Sources), is proposed on the basis of a
simple idea: the more common ideas one source shares with others, the
morereliable the source is. This rule is adaptable for aggregating a large
number of sources among which some are unreliable. It will keep the spirit of
the conjunctive rule to reinforce the belief on the focal elements with which
the sources are in agreement. The mass on the empty set will be kept as an
indicator of the conflict. Moreover, it can be used to elicit the major opinion
among the experts. The experimental results on synthetic mass functionsverify
that the rule can be effectively used to combine a large number of mass
functions and to elicit the major opinion.
