Issue No.04 - October-December (2011 vol.4)
Yan Wang , Macquarie University, Sydney
Lei Li , Macquarie University, Sydney
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TSC.2010.39
In most existing trust evaluation studies, a single value is computed based on the ratings given to a service provider to indicate the current trust level. This is useful but may not represent the trust features well under certain circumstances. Alternatively, a complete set of trust ratings can be transferred to a service client for local trust calculation. But this obviously creates a big overhead in communication as the data set usually has a large size covering a long service history. In this paper, we present a novel two-dimensional aggregation approach consisting of both vertical and horizontal aggregations of trust ratings. The vertical aggregation calculates the aggregated rating representing the trust level for the services delivered in a small time period. The horizontal aggregation applies our proposed optimal algorithm to determine the minimal number of time intervals, within each of which a trust vector with three values can be calculated to represent all the ratings in that time interval and retain the trust features well. Hence, a small set of trust vectors can represent a large set of trust ratings. This is significant for large-scale trust rating transmission and trust evaluation. Experiments have been conducted to illustrate the properties of our proposed approach.
Service trust, reputation-based trust, trust evaluation, trust rating aggregation, trust vector.
Yan Wang, Lei Li, "Two-Dimensional Trust Rating Aggregations in Service-Oriented Applications", IEEE Transactions on Services Computing, vol.4, no. 4, pp. 257-271, October-December 2011, doi:10.1109/TSC.2010.39