Supporting Semantically Enhanced Web Service Discovery for Enterprise Application Integration

The availability of sophisticated Web service discovery mechanisms is an essential prerequisite for increasing the levels of efficiency and automation in EAI. In this chapter, we present an approach for developing service registries building on the UDDI standard and offering semantically-enhanced publication and discovery capabilities in order to overcome some of the known limitations of conventional service registries. The approach aspires to promote efficiency in EAI in a number of ways, but primarily by automating the task of evaluating service integrability on the basis of the input and output messages that are defined in the Web service’s interface. The presented solution combines the use of three technology standards to meet its objectives: OWL-DL, for modelling service characteristics and performing fine-grained service matchmaking via DL reasoning, SAWSDL, for creating semantically annotated descriptions of service interfaces, and UDDI, for storing and retrieving syntactic and semantic information about services and service providers

The Anatomy and Facets of Dynamic Policies

Information flow policies are often dynamic; the security concerns of a program will typically change during execution to reflect security-relevant events. A key challenge is how to best specify, and give proper meaning to, such dynamic policies. A large number of approaches exist that tackle that challenge, each yielding some important, but unconnected, insight. In this work we synthesise existing knowledge on dynamic policies, with an aim to establish a common terminology, best practices, and frameworks for reasoning about them. We introduce the concept of facets to illuminate subtleties in the semantics of policies, and closely examine the anatomy of policies and the expressiveness of policy specification mechanisms. We further explore the relation between dynamic policies and the concept of declassification.Comment: Technical Report of publication under the same name in Computer Security Foundations (CSF) 201

Representing and integrating bibliographic information into the Semantic Web : A comparison of four conceptual models

Integration of library data into the Semantic Web environment is a key issue for libraries and is approached on the basis of interoper- ability between conceptual models. Several data models exist for the representation and publication of library data in the Semantic Web and therefore inter-domain and intra-domain interoperability issues emerge as a growing number of web data are generated. Achieving interoperability for different representations of the same or related entities between the library and other cultural heritage institutions shall enhance rich bibliographic data reusability and support the development of new data-driven information services. This paper aims to investigate common ground and convergences between four conceptual models, namely Functional Requirements for Bibliographic Records (FRBR), FRBR Object-Oriented (FRBRoo), Bibliographic Framework (BIBFRAME) and Europeana Data Model (EDM), enabling semantically-richer interoperability by studying the representation of monographs, as well as of content relationships (derivative and equivalent bibliographic relationships) and of whole-part relationships between them

An intelligent framework for dynamic web services composition in the semantic web

As Web services are being increasingly adopted as the distributed computing technology of choice to securely publish application services beyond the firewall, the importance of composing them to create new, value-added service, is increasing. Thus far, the most successful practical approach to Web services composition, largely endorsed by the industry falls under the static composition category where the service selection and flow management are done a priori and manually. The second approach to web-services composition aspires to achieve more dynamic composition by semantically describing the process model of Web services and thus making it comprehensible to reasoning engines or software agents. The practical implementation of the dynamic composition approach is still in its infancy and many complex problems need to be resolved before it can be adopted outside the research communities. The investigation of automatic discovery and composition of Web services in this thesis resulted in the development of the eXtended Semantic Case Based Reasoner (XSCBR), which utilizes semantic web and AI methodology of Case Based Reasoning (CBR). Our framework uses OWL semantic descriptions extensively for implementing both the matchmaking profiles of the Web services and the components of the CBR engine. In this research, we have introduced the concept of runtime behaviour of services and consideration of that in Web services selection. The runtime behaviour of a service is a result of service execution and how the service will behave under different circumstances, which is difficult to presume prior to service execution. Moreover, we demonstrate that the accuracy of automatic matchmaking of Web services can be further improved by taking into account the adequacy of past matchmaking experiences for the requested task. Our XSCBR framework allows annotating such runtime experiences in terms of storing execution values of non-functional Web services parameters such as availability and response time into a case library. The XSCBR algorithm for matchmaking and discovery considers such stored Web services execution experiences to determine the adequacy of services for a particular task. We further extended our fundamental discovery and matchmaking algorithm to cater for web services composition. An intensive knowledge-based substitution approach was proposed to adapt the candidate service experiences to the requested solution before suggesting more complex and computationally taxing AI-based planning-based transformations. The inconsistency problem that occurs while adapting existing service composition solutions is addressed with a novel methodology based on Constraint Satisfaction Problem (CSP). From the outset, we adopted a pragmatic approach that focused on delivering an automated Web services discovery and composition solution with the minimum possible involvement of all composition participants: the service provider, the requestor and the service composer. The qualitative evaluation of the framework and the composition tools, together with the performance study of the XSCBR framework has verified that we were successful in achieving our goal

Open world reasoning in semantics-aware access control: A preliminary study

We address the relationships between theoretical foundations of Description Logics and practical applications of security-oriented Semantic Web techniques. We first describe the advantages of semantics-aware Access Control and review the state of the art; we also introduce the basics of Description Logics and the novel semantics they share. Then we translate the principle underlying the Little House Problem of DL into a real-world use case: by applying Open World Reasoning to the Knowledge Base modelling a Virtual Organization, we derive information not achievable with traditional Access Control methodologies. With this example, we also show that a general problem such as ontology mapping can take advantage of the enhanced semantics underlying OWL Lite and OWL DL to handle under-specified concepts

Modelling naturalistic argumentation in research literatures: representation and interaction design issues

This paper characterises key weaknesses in the ability of current digital libraries to support scholarly inquiry, and as a way to address these, proposes computational services grounded in semiformal models of the naturalistic argumentation commonly found in research lteratures. It is argued that a design priority is to balance formal expressiveness with usability, making it critical to co-evolve the modelling scheme with appropriate user interfaces for argument construction and analysis. We specify the requirements for an argument modelling scheme for use by untrained researchers, describe the resulting ontology, contrasting it with other domain modelling and semantic web approaches, before discussing passive and intelligent user interfaces designed to support analysts in the construction, navigation and analysis of scholarly argument structures in a Web-based environment

Argumentation-based design rationale - the sharpest tools in the box

In this paper the three main argumentation-based design rationale methodologies - IBIS, QOC and DRL – will be discussed with illustrations of particular points drawn from a working example. The areas of scope, expressiveness in terms of design space and argumentation representation and the resulting usability by human and computer will be examined. Particular attention is paid to how the development of the artifact is being controlled by the evaluation of intentions and objectives that allow consistent goals throughout the design to be formulated, evaluated and modified. Furthermore, decision making within an argumentative context is highlighted

Optimal transport for Latent variable models

Generative models are probabilistic models which aim at approximating the process by which a given dataset is generated. They are well suited to the unsupervised learning setup and constitute intuitive and powerful models providing an interpretable representation of the data. However, learning even simple generative models can be challenging in the traditional Maximum Likelihood framework, due to the inflexibility of the training objective used. Motivated by its topological properties, we will show in this thesis how methods based on Optimal Transport can overcome these difficulties and offer competitive alternatives. Firstly, we show that training generative models that combine both discrete and continuous latent variables can be significantly more effective when using Optimal Transport methods. Such intuitive models are highly motivated by the structure of many real-world datasets but remain hard to train with the most common likelihood-based method, often resulting in the collapse of the discrete latent variables. Secondly, we propose a novel approach based on Optimal Transport to training models with fully Markovian deep-latent hierarchies. Probabilistic models with deep latent-variable structures have powerful modelling capacity, but common approaches often fail to leverage deep-latent hierarchies without complex inference and optimisation schemes. Our method successfully leverages the whole hierarchy of the models and shows competitive generative performance while learning smooth latent manifolds through every layers of the latent hierarchy. Finally, we introduce a new training objective to improve the learning of interpretable and disentangled representation of the data. Our method achieves competitive disentanglement relative to state-of-the-art techniques whilst improving the reconstruction and generation performances of the models

Services and Policies for Care at Home

It is argued that various factors including the increasingly ageing population will require more care services to be delivered to users in their own homes. Desirable characteristics of such services are outlined. The Open Services Gateway initiative has been adopted as a widely accepted framework that is particularly suitable for developing home care services. Service discovery in this context is enhanced through ontologies that achieve greater flexibility and precision in service description. A service ontology stack allows common concepts to be extended for new services. The architecture of a policy system for home care is explained. This is used for flexible creation and control of new services. The core policy language and its extension for home care are introduced, and illustrated through typical examples. Future extensions of the approach are discussed