tailieunhanh - Semantic Web Technologies phần 8

€" việc tạo ra một khái niệm chia sẻ mà không có bất kỳ hướng dẫn hầu như không thể, hoặc ít nhất là tốn thời gian. Chúng tôi kết luận rằng một phương pháp tiếp cận kiểm soát hơn là cần thiết đối với quá trình và điều độ. | THE SWSF APPROACH 217 Figure The layered structure of swsl-rules SWSF 2005 . seen as both specification and implementation language. SWSL-Rules language provides support for service-related tasks like discovery contacting policy specification and so on. It is a layered-based languages as shown in Figure . The core of the SWSL-Rules language is represented by pure Horn sub-set of SWSL-Rules. This subset is extended by adding different features like 1 disjunction in the body and conjunction and implication in the head - this extension is called monotonic Loyd-Topor Mon LT Lloyd 1987 2 negation in the rule body interpreted as nation as failure - this extension is called NAF. Furthermore the Mon LT can be extended by adding quantifiers and implication in the rule body resulting in what is called nonmonotonic Loyd-Topor Nonmon LT extension. Other envisioned extensions are towards 1 Courteous rules Courteous whit two new features restricted classical negation and prioritized rules 2 HiLog - enables meta-programming 3 Frames - add object oriented features like frame syntax types and inheritance 4 Reification - allows rules to be referred and grouped. Finally Equality can be possible extension as well. SWSL-FOL is a First-Order logic which includes features from HiLog and F-Logic. It has as well a layered structure which is depicted in Figure Some of the extensions provided for SWSL-Rules apply for SWSL-FOL as well. The only restriction is that the initial languages should have monotonic semantics. The resulting extensions depicted in Figure are SWSL-FOL Equality SWSL-FOL HiLog and SWSL-FOL Frame. 218 SEMANTIC WEB SERVICES - APPROACHES AND PERSPECTIVES Figure The layers of SWSL-FOL and their relationship to SWSL-Rules sWsF 2005 . . THE IRS-III APPROACH IRS-III13 Domingue et al. 2004 is a framework and implemented platform which acts as a broker mediating between the goals of a user or client and available deployed Web services. The IRS uses WSMO