SA-REST and (S)mashups : Adding Semantics to RESTful Services

The evolution of the Web 2.0 phenomenon has led to the increased adoption of the RESTful services paradigm. RESTful services often take the form of RSS/Atom feeds and AJAX based light weight services. The XML based messaging paradigm of RESTful services has made it possible to compose various services together. Such compositions of RESTful services is widely referred to as Mashups. In this paper, we outline the limitations in current approaches to creating mashups. We address these limitations by proposing a framework called as SA-REST. SA-REST adds semantics to RESTful services. Our proposed framework builds upon the original ideas in WSDL-S, our W3C submission, which was subsequently adapted for Semantic Annotation of WSDL (SAWSDL), now a W3C proposed recommendation. We demonstrate use of microformats for semantic annotation of RESTful services and then the use of such semantically enabled services with better support for interoperability for creating dynamic mashups called SMashups

A Semantic Template Based Designer for Semantic Web Processes

The growing popularity of service oriented computing based on Web services standards is creating a need for paradigms to represent and design business processes. Significant work has been done in the representation aspects with regards to WSBPEL. However, design and modeling of business processes is still an open issue. In this paper, we present a novel designer for business processes, which allows for intuitive modeling of Web processes, as well as using a template based approach for semi-automatically integrating partners either at design time or at deployment time. This work has been done as part of the METEOR-S project, which concentrates on adding semantics to the entire Web process lifecycle

Spatio-Temporal-Thematic Analysis of Citizen Sensor Data: Challenges and Experiences

We present work in the spatio-temporal-thematic analysis of citizen-sensor observations pertaining to real-world events. Using Twitter as a platform for obtaining crowd-sourced observations, we explore the interplay between these 3 dimensions in extracting insightful summaries of social perceptions behind events. We present our experiences in building a web mashup application, Twitris that extracts and facilitates the spatio-temporal-thematic exploration of event descriptor summaries

Semantics Enriched Service Environments

During the past seven years services centric computing has emerged as the preferred approach to architect complex software. Software is increasingly developed by integrating remotely existing components, popularly called services. This architectural paradigm, also called Service Oriented Architecture (SOA), brings with it the benefits of interoperability, agility and flexibility to software design and development. One can easily add or change new features to existing systems, either by the addition of new services or by replacing existing ones. Two popular approaches have emerged for realizing SOA. The first approach is based on the SOAP protocol for communication and the Web Service Description Language (WSDL) for service interface description. SOAP and WSDL are built over XML, thus guaranteeing minimal structural and syntactic interoperability. In addition to SOAP and WSDL, the WS-* (WS-Star) stack or SOAP stack comprises other standards and specification that enable features such as security and services integration. More recently, the RESTful approach has emerged as an alternative to the SOAP stack. This approach advocates the use of the HTTP operations of GET/PUT/POST/DELETE as standard service operations and the REpresentational State Transfer (REST) paradigm for maintaining service states. The RESTful approach leverages on the HTTP protocol and has gained a lot of traction, especially in the context of consumer Web applications such as Maps. Despite their growing adoption, the stated objectives of interoperability, agility, and flexibility have been hard to achieve using either of the two approaches. This is largely because of the various heterogeneities that exist between different service providers. These heterogeneities are present both at the data and the interaction levels. Fundamental to addressing these heterogeneities are the problems of service Description, Discovery, Data mediation and Dynamic configuration. Currently, service descriptions capture the various operations, the structure of the data, and the invocation protocol. They however, do not capture the semantics of either the data or the interactions. This minimal description impedes the ability to find the right set of services for a given task, thus affecting the important task of service discovery. Data mediation is by far the most arduous task in service integration. This has been a well studied problem in the areas of workflow management, multi-database systems and services computing. Data models that describe real world data, such as enterprise data, often involve hundreds of attributes. Approaches for automatic mediation have not been very successful, while the complexity of the models require considerable human effort. The above mentioned problems in description, discovery and data mediation pose considerable challenge to creating software that can be dynamically configured. This dissertation is one of the first attempts to address the problems of description, discovery, data mediation and dynamic configuration in the context of both SOAP and RESTful services. This work builds on past research in the areas of Semantic Web, Semantic Web services and Service Oriented Architectures. In addition to addressing these problems, this dissertation also extends the principles of services computing to the emerging area of social and human computation. The core contributions of this work include a mechanism to add semantic metadata to RESTful services and resources on the Web, an algorithm for service discovery and ranking, techniques for aiding data mediation and dynamic configuration. This work also addresses the problem of identifying events during service execution, and data integration in the context of socially powered services

SA-REST: Using Semantics to Empower RESTful Services and Smashups with Better Interoperability and Mediation

Presented at the Semantic Technology Conference, San Jose, CA, May 22, 2008

SA-REST: Semantically Interoperable and Easier-to-Use Services and Mashups

Services based on the representational state transfer (REST) paradigm, a lightweight implementation of a service-oriented architecture, have found even greater success than their heavyweight siblings, which are based on the Web Services Description Language (WSDL.) and SOAP. By using XML-based messaging, RESTful services can bring together discrete data from different services to create meaningful data sets; mashups such as these are extremely popular today