What can context do for web services?

PurposeIn the last decade, web services have become a major technology to implement loosely coupled business processes and perform application integration. Through the use of context, a new generation of web services, namely context‐aware web services (CASs), is currently emerging as an important technology for building innovative context‐aware applications. Unfortunately, CASs are still difficult to build. Issues like lack of context provisioning management approach and lack of generic approach for formalizing the development process need to be solved in the first place for easy and effective development of CASs. The purpose of this paper is to investigate the techniques on developing CASs.Design/methodology/approachThe paper focuses on introducing a model‐driven platform, called ContextServ, and showcasing how to use this platform to rapidly develop a context‐aware web application, Smart Adelaide Guide. ContextServ adopts a model‐driven development (MDD) approach where a Unified Modeling Language (UML)‐based modeling language – ContextUML – is used to model web services and its context‐awareness features.FindingsThe paper presents novel techniques for efficient and effective development of CASs using a MDD approach. The ContextServ platform is the only one that provides a comprehensive software toolset that supports graphical modeling and automatic model transformation of CASs.Practical implicationsThe proposed approach has been validated in practice by developing various CASs. The experimental study demonstrates the efficiency and effectiveness of the approach.Originality/valueThe paper presents a novel platform called ContextServ, which offers a set of visual editing and automation tools for easy and fast generating and deploying CASs.

Context-aware web services have been attracting significant attention as an important approach for improving the usability of web services. In this paper, we explore a novel approach to model dynamic behaviors of interacting context-aware web services, aiming to effectively process and take advantage of contexts and realize behavior adaptation of web services and further to facilitate the development of context-aware application of web services. We present an interaction model of context-aware web services based on context-aware process network (CAPN), which is a data-flow and channel-based model of cooperative computation. The CAPN is extended to context-aware web service network by introducing a kind of sensor processes, which is used to catch contextual data from external environment. Through modeling the register link's behaviors, we present how a web service can respond to its context changes dynamically. The formal behavior semantics of our model is described by calculus of communicating systems process algebra. The behavior adaptation and context awareness in our model are discussed. An eXtensible Markup Language-formatted service behavior description language named BML4WS is designed to describe behaviors and behavior adaptation of interacting context-aware web services. Finally, an application case is demonstrated to illustrate the proposed model how to adapt context changes and describe service behaviors and their changes.

Context-aware Web services are identified as an important technology to support new applications on the future Internet. Context information has several qualities that make the development of these services challenging, compared to conventional, Web services. Therefore, sound software engineering practices are needed during their development and execution. This article discusses a novel software engineering-based approach, which leverages the benefits of model-driven architecture, aspect-oriented modeling, and formal model checking, for modeling and verifying context-aware services. The approach is explored using a real-world case study in intelligent transport. An evaluation framework is established to validate the main methods and tools employed.

Context-aware Web services are emerging as a promising technology for the electronic businesses in mobile and pervasive environments. Unfortunately, complex context-aware services are still hard to build. In this paper, we present a modeling language for the model-driven development of context-aware Web services based on the Unified Modeling Language (UML). Specifically, we show how UML can be used to specify information related to the design of context-aware services. We present the abstract syntax and notation of the language and illustrate its usage using an example service. Our language offers significant design flexibility that considerably simplifies the development of context-aware Web services.

Context-awareness is gaining wide importance, especially when targeting pervasive environments, whereas Web Services are often exploited as building blocks of context-aware applications because of their interoperability properties. In this framework, Web Services can be used as business services requiring context data for their functionality, but also as context sources offering access to context information. Combining the development of context-aware Web Services with Model-Driven Engineering techniques requires the identification and matching of appropriate context models with Web Service models. In this paper, a new ongoing research direction is presented, which refers to model transformation for allowing the identification of appropriate context sources and ensuring their compatibility with Web Services. Matchmaking principles between Web Service and context models are examined in order to extract a reasoning mechanism on context adaptation compatibility. In specific, the principles of graph transformation are mainly exploited.

Standardized web services technology has been used in the construction industry to support activities such as sensing data integration, supply chain collaboration, and performance monitoring. Currently these web services are used for exchanging messages with simple structure and small size. However, building information models often contain rich information and are huge in size. Therefore, retrieving and exchanging building information models using standardized web services technology is challenging. This paper discusses the usage of ontologies and context awareness in standardized web services technology to facilitate efficient and lightweight information retrieval and exchange. Ontologies for building information such as Industry Foundation Classes (IFC) and aecXML have been developed for over a decade and become mature. These ontologies can be leveraged to structure the input and output messages of web services. On the other hand, context awareness not only provides data security according to user’s location, time, and profile, but also enables retrieval and exchange of partial information models. This paper presents and demonstrates an ontology-based context aware web service framework that is designed for retrieval and updating of building information models.

There are major barriers of entry that prevent individuals or small businesses from taking advantage of Web services to enhance their businesses. Creating a Web service is a task that would normally require someone with technical skills in programming. The overall cost of maintenance of the servers is also usually prohibitively high. The LOMS (local mobile services) project addresses the above issues and tries to bring a context sensitive Web service creation to the masses. In this project, by combining the concept of an open integrated SOA platform and a style-sheet transformation, nontechnical users as well as small businesses are able to create and manage context-aware Web services easily and quickly. This paper focuses on the service creation aspect.

In web service based dynamic E-commerce applications, inclusion of context-aware features in the delivered services is an important approach to improve the efficiency of the dialogues between users and systems. In this paper, we explore a novel context-aware web service composition model for dynamic E-commerce applications, aims to effectively process and take advantage of contexts and facilitate the development of context-aware E-commerce applications. We present a context-aware composition model of web services for E-commerce applications based on a formal model, Context-aware Process Network (CAPN), which is a dataflow and channel based model of cooperative computation. We extend the Context-aware Process Network to a context-aware web service composition model named ECModel by adding a kind of sensor processes which is used to catch contextual data from external environment. Through modeling the register link's behaviors, we present how a web service can respond to its context changes dynamically. We describe formal behavior semantics of ECModel and realize context-awareness in this model. We also present a composition framework of dynamic E-commerce based on ECModel.

Due to the high availability and also the distributed nature of published web services on the Web, efficient discovery and retrieval of relevant services that meet user requirements can be a challenging task. In this paper, we present a semantics based web service retrieval framework that uses natural language processing techniques to extract a service’s functional information. The extracted information is used to compute the similarity between any given service pair, for generating additional metadata for each service and for classifying the services based on their functional similarity. The framework also adds natural language querying capabilities for supporting exact and approximate matching of relevant services to a given user query. We present experimental results that show that the semantic analysis & automatic tagging effectively captured the inherent functional details of a service and also the similarity between different services. Also, a significant improvement in precision and recall was observed during Web service retrieval when compared to simple keyword matching search, using the natural language querying interface provided by the proposed framework.

Context-Aware Services are emerging as a promising technology for the pervasive computing environments. Unfortunately, development of successful CASs (Context-Aware Services) still remains as a hard task. In this paper, we propose SIMP4P (Simulation-based Personalization Web Services Composer for Pervasive Computing), a simulation-based development framework for context-aware services. SIMP4P framework (semi-) automates the development process of CAS, including context management, CAS composition, and validation. In this framework, all or parts of the comprising web services are simulated to efficiently test out the resulting CAS before actual deployment.