Knowledge Update in Collaborative Knowledge Sharing Systems

2. System Model

The system architecture under consideration is shown in Figure 1. Our cooperative KBS consists of a set of sources with local knowledge base system {KBS_i, for 1 ≤ i ≤ m}, where each KBS_i is a pre-existing autonomous knowledge management system contains knowledge data source. Each system provides a set of services to share and access its knowledge locally and remotely. For example each system provides acquaintance services for creating acquaintances with other systems, query service for retrieving information over the network, and update service for updating local and remote knowledge. Once a system joins the network, it can establish acquaintances with other systems exchanging their schemas and use services exists in local system and its acquaintances. An acquaintance is a connection between two systems and is established by generating mapping tables (Kementsietsidis et al., 2003) on both systems. The acquaintances are transient since each system is fully autonomous and joins or leaves the network at its own will. Formally, we can define our collaborative KBS as follows.

Figure 1.

System model

• Definition 1:A collaborative KBS is a pair (N,M). Here, N = {(K,L}) is an undirected graph, where K = {KB₁, …,KB_n} is a set of knowledge base system or simply called sources, L = {(KB_i, KB_j) |KB_i, KB_j ∈ K} is a set of acquaintances. Each source KB_i is associated with a knowledge database with schema KDB_i[W_i], and each acquaintance (i,j) is associated with a set M_ij ∈ M of mapping tables.