Using new fusion operations to improve trust expressiveness of subjective logic

Subjective logic provides a means to describe the trust relationship of the real world. However, existing fusion operations it offers treat fused opinions equally, which makes it impossible to deal with the weighted opinions effectively. A. Jøsang presents a solution, which combines the discounting operator and the fusion operator to produce the consensus to the problem. In this paper, we prove that this approach is unsuitable to deal with the weighted opinions because it increases the uncertainty of the consensus. To address the problem, we propose two novel fusion operators that are capable of fusing opinions according to the weight of opinion in a fair way, and one of the strengths of them is improving the trust expressiveness of subjective logic. Furthermore, we present the justification on their definitions with the mapping between the evidence space and the opinion space. Comparisons between existing operators and the ones we proposed show the effectiveness of our new fusion operations.