DAML-S: Web Service Description for the Semantic Web

684

383

Abstract. Though research on the Semantic Web has progressed at a steady pace, its promise has yet to be realized. One major difficulty is that, by its very nature, the Semantic Web is a large, uncensored system to which anyone may contribute. This raises the question of how much credence to give each source. We cannot expect each user to know the trustworthiness of each source, nor would we want to assign top-down or global credibility values due to the subjective nature of trust. We tackle this problem by employing a web of trust, in which each user maintains trusts in a small number of other users. We then compose these trusts into trust values for all other users. The result of our computation is not an agglomerate "trustworthiness" of each user. Instead, each user receives a personalized set of trusts, which may vary widely from person to person. We define properties for combination functions which merge such trusts, and define a class of functions for which merging may be done locally while maintaining these properties. We give examples of specific functions and apply them to data from Epinions and our BibServ bibliography server. Experiments confirm that the methods are robust to noise, and do not put unreasonable expectations on users. We hope that these methods will help move the Semantic Web closer to fulfilling its promise.

Section: Introductionmentioning

confidence: 99%

Trust Management for the Semantic Web

Richardson

Agrawal

Domingos

2003

684

383

“…An example of this is the DMA2FOAF translation service 9 that translates markup for <dma:Speaker> concepts and converts these into <foaf:Person> concepts (see Fig 4). The DMA2FOAF translation service describes its capabilities using the DAML-S [1,2] service description. This includes information about the Process Model, i.e.…”

Section: Discovery Services and Translation Agentsmentioning

confidence: 99%

“…This structure-representation may facilitate some level of automation for tasks such as human-oriented database search and the formation of messages understood by a service's interface. However, automatic composition of metaservices and interoperation between these services can only be achieved through the use of semantic-based frameworks such as DAML-S [1,2]. DAML-S is a DAML+OIL [4] ontology for describing the properties and capabilities of web services.…”

Section: Introductionmentioning

confidence: 99%

Processing Schedules Using Distributed Ontologies on the Semantic Web

Payne

Singh

Sycara

2002

Self Cite

Abstract. The Semantic Web uses formal distributed ontologies for representing relationships among concepts in the real world. A structured framework such as this allows agents to peruse and reason about published knowledge without the need for scrapers, information agents, and centralized ontologies. However, in order to process any information, an agent must be familiar with the underlying ontology used to markup that information. However, no single agent can be expected to be familiar with all possible ontologies that may be available on the Semantic Web. Therefore, translation services that transform concepts defined within previously unknown ontologies into known concepts allow agents to understand the available information and hence achieve their goal. This transformation may be achieved by invoking specific markup translation services or by logical reasoning through other shared ontologies. The RETSINA Calendar Agent (RCal) is a Distributed Meeting Scheduling Agent that processes schedules marked up on the Semantic Web, and imports them into the user's Personal Information Manager. Translation services, which are used to translate unknown concepts into known concepts, which are located using a DAML-S based service discovery mechanisms. In this paper, we present RCal, and demonstrate how it extracts and uses meaningful knowledge from the semantic markup. In addition, we describe how web-service discovery mechanisms are used when new concepts are encountered.

“…Currently, there are standards or languages that help building composed web services such as: WSFL [7], DAML-S [8], and BPEL [9]. These languages make the web services composition process easier by providing concepts to represent partners and orchestrate their interactions.…”

Section: Introductionmentioning

confidence: 99%

Towards the Testing of Composed Web Services in 3rd Generation Networks

Benharref

Dssouli

Glitho

et al. 2006

Abstract. With the proliferation of web services in business and as the number of web services is increasing, it is anticipated that a single web service will become insufficient to handle multitude, heterogeneous, and complex functions. Hence, web service composition will be used to create new value added services with a wide range of functionalities. Management of a composed web service is a complex issue compared to the management of a non-composed (basic) web service. In this paper, we propose a multi-observer architecture for detecting and locating faults in composed web services. It makes use of a network of observers that cooperate together to observe a composed web service. An observation strategy based on a set of heuristics is presented to reduce the number of web services to be observed. Observers are developed as mobile agent observers to help reducing the load introduced by the observation. Algorithms for fault detection, notification, and collaboration between observers are described. Finally, the architecture is illustrated through a case study for observing a composed teleconferencing web services in a 3G network. Different components of the architecture are developed. The network load introduced by the observation is measured and the fault detection capabilities of the architecture are discussed.