Semantic Web Services for Multi-Agent Systems Interoperability

Agent-based technologies are often used including existing web services. The outputs of some services are also frequently used as inputs for other services, including other MAS. However, while agent-based technologies can be used to provide services, these are not described using the same semantic web technologies web services use, which makes it difficult to discover, invoke and compose them with web services seamlessly. In this paper, we analyse different agent-based technologies and how these can be described using extensions to OWL-S. Additionally, we propose an architecture that facilitates these services’ usage, where services of any kind can be registered and executed (semi-)automatically.The present work has been developed under the PIANISM Project (ANI|P2020 40125) and has received funding from FEDER Funds through NORTE2020 program and from National Funds through Fundação para a Ciência e a Tecnologia (FCT) under the project UID/EEA/00760/2019. Gabriel Santos is supported by national funds through FCT PhD studentship with reference SFRH/BD/118487/2016.info:eu-repo/semantics/publishedVersio

A unifying perspective on protocol mediation: interoperability in the Future Internet

Given the highly dynamic and extremely heterogeneous software systems composing the Future Internet, automatically achieving interoperability between software components —without modifying them— is more than simply desirable, it is quickly becoming a necessity. Although much work has been carried out on interoperability, existing solutions have not fully succeeded in keeping pace with the increasing complexity and heterogeneity of modern software, and meeting the demands of runtime support. On the one hand, solutions at the application layer target higher automation and loose coupling through the synthesis of intermediary entities, mediators, to compensate for the differences between the interfaces of components and coordinate their behaviours, while assuming the use of the same middleware solution. On the other hand, solutions to interoperability across heterogeneous middleware technologies do not reconcile the differences between components at the application layer. In this paper we propose a unified approach for achieving interoperability between heterogeneous software components with compatible functionalities across the application and middleware layers. First, we provide a solution to automatically generate cross-layer parsers and composers that abstract network messages into a uniform representation independent of the middleware used. Second, these generated parsers and composers are integrated within a mediation framework to support the deployment of the mediators synthesised at the application layer. More specifically, the generated parser analyses the network messages received from one component and transforms them into a representation that can be understood by the application-level mediator. Then, the application-level mediator performs the necessary data conversion and behavioural coordination. Finally, the composer transforms the representation produced by the application-level mediator into network messages that can be sent to the other component. The resulting unified mediation framework reconciles the differences between software components from the application down to the middleware layers. We validate our approach through a case study in the area of conference management

SSWAP: A Simple Semantic Web Architecture and Protocol for semantic web services

<p>Abstract</p> <p>Background</p> <p>SSWAP (<b>S</b>imple <b>S</b>emantic <b>W</b>eb <b>A</b>rchitecture and <b>P</b>rotocol; pronounced "swap") is an architecture, protocol, and platform for using reasoning to semantically integrate heterogeneous disparate data and services on the web. SSWAP was developed as a hybrid semantic web services technology to overcome limitations found in both pure web service technologies and pure semantic web technologies.</p> <p>Results</p> <p>There are currently over 2400 resources published in SSWAP. Approximately two dozen are custom-written services for QTL (Quantitative Trait Loci) and mapping data for legumes and grasses (grains). The remaining are wrappers to Nucleic Acids Research Database and Web Server entries. As an architecture, SSWAP establishes how clients (users of data, services, and ontologies), providers (suppliers of data, services, and ontologies), and discovery servers (semantic search engines) interact to allow for the description, querying, discovery, invocation, and response of semantic web services. As a protocol, SSWAP provides the vocabulary and semantics to allow clients, providers, and discovery servers to engage in semantic web services. The protocol is based on the W3C-sanctioned first-order description logic language OWL DL. As an open source platform, a discovery server running at <url>http://sswap.info</url> (as in to "swap info") uses the description logic reasoner Pellet to integrate semantic resources. The platform hosts an interactive guide to the protocol at <url>http://sswap.info/protocol.jsp</url>, developer tools at <url>http://sswap.info/developer.jsp</url>, and a portal to third-party ontologies at <url>http://sswapmeet.sswap.info</url> (a "swap meet").</p> <p>Conclusion</p> <p>SSWAP addresses the three basic requirements of a semantic web services architecture (<it>i.e</it>., a common syntax, shared semantic, and semantic discovery) while addressing three technology limitations common in distributed service systems: <it>i.e</it>., <it>i</it>) the fatal mutability of traditional interfaces, <it>ii</it>) the rigidity and fragility of static subsumption hierarchies, and <it>iii</it>) the confounding of content, structure, and presentation. SSWAP is novel by establishing the concept of a canonical yet mutable OWL DL graph that allows data and service providers to describe their resources, to allow discovery servers to offer semantically rich search engines, to allow clients to discover and invoke those resources, and to allow providers to respond with semantically tagged data. SSWAP allows for a mix-and-match of terms from both new and legacy third-party ontologies in these graphs.</p

Query Answering for OWL-DL with Rules.

Both OWL-DL and function-free Horn rules1 are decidable logics with interesting, yet orthogonal expressive power: from the rules perspective, OWL-DL is restricted to tree-like rules, but provides both existentially and universally quantified variables and full, monotonie negation. From the description logic perspective, rules are restricted to universal quantification, but allow for the interaction of variables in arbitrary ways. Clearly, a combination of OWL-DL and rules is desirable for building Semantic Web ontologies, and several such combinations have already been discussed. However, such a combination might easily lead to the undecidability of interesting reasoning problems. Here, we present a decidable such combination which is, to the best of our knowledge, more general than similar decidable combinations proposed so far. Decidability is obtained by restricting rules to so-called DL-safe ones, requiring each variable in a rule to occur in a non-DL-atom in the rule body. We show that query answering in such a combined logic is decidable, and we discuss its expressive power by means of a non-trivial example. Finally, we present an algorithm for query answering in SHIQ(D) extended with DL-safe rules based on the reduction to disjunctive datalog. © Springer-Verlag 2004

An Intelligent Web Service System

The Semantic Web extends today&apos;s Web technology by enabling machinehuman as well as machine-machine interactions with well-defined semantics of Web resources and services. Automated interoperation among machines demands a tool which can manipulate semantic information, enhances understanding and reasoning, and leads to machine-machine collaboration. This Intelligent Web Service (IWS) System presents a declarative approach to the construction of Semantic Web applications by means of a unified modeling language XML Declarative Description (XDD) and an XML-based declarative programming language XML Equivalent Transformation (XET). With XDD&apos;s expressiveness and inference capabilities as well as XET&apos;s computational, document- and query-processing mechanisms, IWS introduces a uniform representation of ontology axioms, ontology definitions and instances as well as application constraints and rules in machine-processible form. It is also employed to create a prototype of B2B travel bus inesses as a demonstration of the framework&apos;s practicality and potential usage on the Semantic Web