There is an increasing trend in moving desktop applications to web browsers, even when the web server is running on the same desktop machine. In this paper, we go further in this direction and show how to combine a web server, a web application framework (enhanced to support desktop-like Model–View–Controller interaction) and a context-aware architecture to develop web-based mobile context-aware applications. By using this approach we take advantage of the well-established web paradigm to design the graphical user interfaces (GUIs) and the inherent ability of the web to mash up applications with external components (such as Google Maps). On top of that, since the web server runs on the device itself, the application can access local resources (such as disk space or sensing devices, which are indispensable for context-aware systems) avoiding the sandbox model of the web browsers. To illustrate our approach we show how a mobile hypermedia system has been built on top of our platform.

Limitations of sensors and the situation of a specific measurement can affect the quality of context information that is implicitly collected in pervasive environments. The lack of information about Quality of Context (QoC) can result in degraded performance of context-aware systems in pervasive environments, without knowing the actual problem. Context-aware systems can take advantage of QoC if context producers also provide QoC metrics along with context information. In this paper, we analyze QoC and present our model for processing QoC metrics. We evaluate QoC metrics considering the capabilities of sensors, circumstances of specific measurement, requirements of context consumer, and the situation of the use of context information. We also illustrate how QoC metrics can facilitate in enhancing the effectiveness and efficiency of different tasks performed by a system to provide context information in pervasive environments.

In order to be able to specify and design ubiquitous applications, it is necessary to rely on a precise and formal representation of context. Aiming at reducing the gap between the formal specification and the design of a concrete ubiquitous application, we have proposed an approach to specify a context-aware system at three levels of abstraction. This specification uses the Algebra of Contextualized Ontologies, which is based on Category Theory and takes contextualization as a basic notion, proposing a small set of simple and powerful operations to compose and decompose contextualized ontologies. In this paper, we present a revised version of the algebra and algorithms to compute the algebraic operations. We exemplify our approach along with a concrete ubiquitous computing scenario. Moreover, by taking advantage of Category Theory foundations, we show that it is possible to derive the algorithms for each algebraic operation from simple modifications of a single basic algorithm.

The Web search has special characteristics against the desktop search when realized from mobile devices. To establish an improvement within this paradigm, an option is to take into account the context from which the search is developed. To conceptualize the mobile context, we propose the use of ontologies, which will include the device characteristics, environmental conditions and user preferences, among other term conceptualizations. This context definition would be used to determinate the behavior of a word recommendation when searching from mobile devices. As an essential process of creating this context ontology, we have made a real user's evaluation of the ontology terms by means of a survey. This paper shows a brief introduction to the project and focuses mainly on the results obtained in this concept's evaluation.

As Web Services and the Semantic Web become more important, enabling technologies such as Web service ontologies will grow larger. At the same time, use of mobile devices to access Web services has doubled in the last year. The ability of these resource-constrained devices to download and reason across ontologies to support service discovery are severely limited. Since concrete agents typically only needs a subset of what is described in a Web service ontology to complete their task, a reduced ontology can be created. Measuring the quality of a reduced ontology, in both knowledge content and performance, is a nontrivial task. Expert analysis of the ontologies is time-consuming and unreliable. We propose two measures of knowledge content and performance. Mean average recall (MAR) with respect to the original ontology compares the data returned from a series of queries related to a particular concept of interest. Mean average performance (MAP) compares the download and reasoning speedup of the reduced ontology with respect to the original ontology. Neither of these values can be computed easily, therefore we propose a set of ontology metrics to predict these values. In this paper, we develop two prediction models for MAR and MAP based on these metrics. These models are based on analysis of 23 ontologies from five domains. To compute MAR, a specific set of queries for each domain was applied to each candidate reduced ontology along with the original ontology. To compute MAP, a simulated mobile device will download and process of each ontology along with the original ontology. We believe this model allows a speedy selection of a reduced ontology that contains the knowledge content and performance speedup needed by a mobile device for service discovery.

Traditional Route Search aims at finding the path that goes through geographical entities that are relevant to the provided search terms from the start point to the end point. Without constraints, traditional Route Search visiting multiple locations is unreliable because locations may close after a specified time. In this paper, time constraint (operating hours of each location) is drawn into Route Search query in order to make the query more realistic. Two methods are proposed in this paper, namely Route Search for fixed locations (RFix) and Route Search for flexible locations (RFlex). These two queries are different from the existing Route Search query because (1) the end point is not pre-defined and (2) time constraint is involved. Our two proposal queries consider whether the locations are specifically pre-defined by the user or only the location types are specified. In each method, two propositions are presented for pruning expansion branches, which highly improves the performance. Our experiments verified the applicability of RFix and RFlex to solve Route Search queries with time constraint queries.

Information services facilitate users to exploit applications over the network and access them from the remote system at the client side. In this paper, we describe the design and development of information services for novelty mining, which allows users to access the novel yet relevant information of a given topic. Several methodologies regarding novelty mining such as novelty scoring, novelty threshold, novelty feedback, and document-to-sentence technique are described. In addition to Web services, mobile information services are also described. Modelling and implementing information services for novelty mining are especially useful for users to reduce their information overload. We describe the challenging issue of decomposing the complex novelty mining application into several smaller and simpler modules, which are later implemented as services on the Web as well as mobile devices. After deploying our information services for novelty mining, test cases are provided to demonstrate the system. Our information services for novelty mining are confirmed to be helpful in increasing the efficiency of enterprise users in gathering novel information from incoming text. By studying the design and development of information services for novelty mining, we can benefit other developers in investigating effective techniques for developing enterprise services for other real-world applications.

Lack of sufficient semantic description in the content of Web services makes it difficult to find and compose suitable Web services during analysis, search, and matching processes. Semantic Web Services are Web services that have been enhanced with formal semantic description, which provides well-defined meaning. Due to insertion of semantics, meeting user demands will be made possible through logical deductions achieving resolutions automatically. We have developed an inference-based semantic business process composition agent (SCA) that employs inference techniques. The semantic composition agent system is responsible for the synthesis of new services from existing ones in a semi-automatic fashion. SCA System composes available Web Ontology Language for Web services atomic processes utilizing Revised Armstrong's Axioms (RAAs) in inferring functional dependencies. RAAs are embedded in the knowledge base ontologies of SCA System. Experiments show that the proposed SCA System produces process sequences as a composition plan that satisfies user's requirement for a complex task. The novelty of the SCA System is that for the first time Armstrong's Axioms are revised and used for semantic-based planning and inferencing of Web services.

This paper discusses a goal-based approach for the engineering of capacity-driven Web services. In this approach, goals are established to first, define the roles that these Web services will play in implementing business applications, second, frame the requirements that will be put on these Web services, and third, identify the processes in terms of business logics that these Web services will carry out. Because of the nature of capacity-driven Web services compared with regular (i.e. mono-capacity) Web services, their engineering in terms of design, development, and deployment takes place in a different way. A Web service that is empowered with several capacities, which are basically separate groups of operations to execute, has to choose one capacity for triggering at run-time. To this end, the Web service takes into account different types of requirements like data and privacy that are put on each capacity that empowers this Web service.