A Semantic Search Algorithm for Peer-to-Peer Open Hypermedia Systems

We consider a collaborative application scenario in Open Hypermedia Systems. We describe a semantic search algorithm to discover semantically equivalent or related resources across distributed link databases, otherwise known as linkbases. Our approach differs from traditional crawler based search mechanisms because it relies on clustering of semantically related entities. It creates clusters of related semantic entities to expedite the search for resources in a random network. It uses a distance-vector based heuristic to guide the search. Our results confirm that the algorithm yields high search efficiency in collaborative environments where the change in content published by each participant is rapid and random

A Distance-based Semantic Search Algorithm for Peer-to-Peer Open Hypermedia Systems

We consider the problem of content management in dynamically created collaborative environments. We describe the problem domain with the aid of a collaborative application in Open Hypermedia Systems, which allows individual users to share their link databases, otherwise known as linkbases. The RDF specification is utilised to express and categorise resources stored in a linkbase. This paper describes a semantic search mechanism to discover semantically related resources across such distributed linkbases. Our approach differs from the traditional crawler based search mechanism since it relies on the clustering of semantically related entities to expedite the search for resources in a randomly created network and uses distance-vector based heuristics to guide the search. Our experimental results indicate that the algorithm yields high search effectiveness in collaborative environments where changes in content published by each participant are rapid and random

A Distance Based Semantic Search Algorithm for Peer-to-Peer Open Hypermedia Systems

We consider the problem of content management in dynamically created collaborative environments. We describe the problem domain with the aid of a collaborative application in Open Hypermedia Systems, which allows individual users to share their link databases, otherwise known as linkbases. The RDF specification is utilised to express and categorise resources stored in a linkbase. This paper describes a semantic search mechanism to discover semantically related resources across such distributed linkbases. Our approach differs from the traditional crawler based search mechanism since it relies on the clustering of semantically related entities to expedite the search for resources in a randomly created network and uses distance-vector based heuristics to guide the search. Our experimental results indicate that the algorithm yields high search effectiveness in collaborative environments where changes in content published by each participant are rapid and random

Transparent fault tolerance for web services based architectures

Abstract. Service-based architectures enable the development of new classes of Grid and distributed applications. One of the main capabilities provided by such systems is the dynamic and flexible integration of services, according to which services are allowed to be a part of more than one distributed system and simultaneously serve different applications. This increased flexibility in system composition makes it difficult to address classical distributed system issues such as fault-tolerance. While it is relatively easy to make an individual service fault-tolerant, improving fault-tolerance of services collaborating in multiple application scenarios is a challenging task. In this paper, we look at the issue of developing fault-tolerant service-based distributed systems, and propose an infrastructure to implement fault tolerance capabilities transparent to services.

Personalised Grid service discovery

We take a broad view that ultimately Grid- or Web-services must be located via personalised, semantic-rich discovery processes. We argue that such processes must rely on the storage of arbitrary metadata about services that originates from both service providers and service users. Examples of such metadata are reliability metrics, quality of service data, or semantic service description markup. This paper presents UDDI-Mt, an extension to the standard UDDI service directory approach that supports the storage of such metadata via a tunnelling technique that ties the metadata store to the original UDDI directory. We also discuss the use of a rich, graph-based RDF query language for syntactic queries on this data. Finally, we analyse the performance of each of these contributions in our implementation

A security pattern classification based on Data integration

Revised paper from the third International Conference, ICISSP 2017, Porto, Portugal, February 19-21, 2017International audienceSecurity patterns are design patterns specialised to provide reusable and general solutions to recurring security problems. These patterns , which capture the strengths of different security approaches, are intended to make the design of maintainable and secure applications easier. The pattern community is continuously providing new security patterns (180 patterns are available at the moment). For a given problem, this growing pattern set along with their abstract presentations make the security pattern choice tedious, even for experts in software design. We contribute in this issue by presenting a method of security pattern classification based upon data extraction and integration. The pattern classification is semi-automatically inferred by means of a data-store integrating disparate publicly available security data. This classification exposes relationships among software attacks, weaknesses, security principles and security patterns. It expresses the pattern combinations that can counter a given attack. Besides the pattern classification, we show that the data-store can be used to generate Attack Defense Trees. In our context, these illustrate, for a given attack, its sub-attacks and the related defenses given under the form of security pattern combinations. Such trees make the pattern classification more readable even for beginners in security patterns. Finally, we evaluate on 25 human subjects the benefits of using Attack Defense Trees and a classification established for Web applications, which covers 215 attacks, 136 software weaknesses, 66 security principles and 26 security patterns

On the Use of Agents in a BioInformatics Grid

MyGrid is an e-Science Grid project that aims to help biologists and bioinformaticians to perform workflow-based in silico experiments, and help to automate the management of such workflows through personalisation, notification of change and publication of experiments. In this paper, we describe the architecture of myGrid and how it will be used by the scientist. We then show how myGrid can benefit from agents technologies. We have identified three key uses of agent technologies in myGrid: user agents, able to customize and personalise data, agent communication languages offering a generic and portable communication medium, and negotiation allowing multiple distributed entities to reach service level agreements