Context for Ubiquitous Data Management

In response to the advance of ubiquitous computing technologies, we believe that for computer systems to be ubiquitous, they must be context-aware. In this paper, we address the impact of context-awareness on ubiquitous data management. To do this, we overview different characteristics of context in order to develop a clear understanding of context, as well as its implications and requirements for context-aware data management. References to recent research activities and applicable techniques are also provided

Towards model-driven requirements analysis for context-aware well-being systems

Research interest in the domain of pervasive systems has seen a rapid increase, evident from the amount of research papers being published each year. These systems are to blend in with everyday life, being completely unobtrusive. Through the use of sensors, pervasive systems can become context-aware. As such, they are able to use this context information in order to improve the services provided to the user. Interesting fields of application are those of health-care and well-being. The COMMIT SWELL project aims to improve both physical and mental well-being by developing a sensor-based context-aware system. This system is to (i) aid the user into improving his own lifestyle by giving him insight in his personal activity, and (ii) support the user in his work. In the domain of context-aware systems, we find that requirements have to align perfectly with the features to be offered by the system. If not, the system will become a hindrance to the user, who will then neglect it. Requirements engineering and architectural development for this type of system is largely unexplored territory. A bottom-up approach is often used: little attention is paid to requirements engineering up front, and architectures are created without having reuse in mind. Our objective is to improve the reuse of system requirements and architecture, resulting in an improvement of alignment between these artifacts. In order to facilitate this alignment, we aim to create a model-driven method that allows for bi-directional transformation between requirements and architecture at design time. Current results in the project include a literature study, a list of domain requirements for context-aware well-being systems and a reference architecture and descriptions for two demonstrators within the COMMIT SWELL project. From literature, we found that current methods for requirements engineering in this domain are either too high, or too low level, preventing proper reuse of artifacts in the next phase of the design process, as well as the need for high levels of both domain and system modeling expertise. Furthermore, we found that tool support model-driven development of context-aware well-being applications is currently lacking. Future research will initially focus on the specific requirements found in the context-aware application domain. After this, we will be looking at the link between specific requirements and architectural components, and whether this link exists uni-directionally or bi-directionally. Finally, we will be investigating if automatic alignment between requirements and architecture can be achieved

Requirements Engineering of Context-Aware Applications

Context-aware computing envisions a new generation of smart applications that have the ability to perpetually sense the user’s context and use these data to make adaptation decision in response to changes in the user’s context so as to provide timely and personalized services anytime and anywhere. Unlike the traditional distribution systems where the network topology is fixed and wired, context-aware computing systems are mostly based on wireless communication due to the mobility of the network nodes; hence the network topology is not fixed but changes dynamically in an unpredictable manner as nodes join and the leave network, in addition to the fact that wireless communication is unstable. These factors make the design and development of context-aware computing systems much more challenging, as the system requirements change depending on the context of use. The Unified Modelling Language (UML) is a graphical language commonly used to specify, visualize, construct, and document the artefacts of software-intensive systems. However, UML is an all-purpose modelling language and does not have notations to distinguish context-awareness requirements from other system requirements. This is critical for the specification, visualization, construction and documentation of context-aware computing systems because context-awareness requirements are highly important in these systems. This thesis proposes an extension of UML diagrams to cater for the specification, visualization, construction and documentation of context-aware computing systems where new notations are introduced to model context-awareness requirements distinctively from other system requirements. The contributions of this work can be summarized as follows: (i) A context-aware use case diagram is a new notion which merges into a single diagram the traditional use case diagram (that describes the functions of an application) and the use context diagram, which specifies the context information upon which the behaviours of these functions depend. (ii) A Novel notion known as a context-aware activity diagram is presented, which extends the traditional UML activity diagrams to enable the representation of context objects, context constraints and adaptation activities. Context constraints express conditions upon context object attributes that trigger adaptation activities; adaptation activities are activities that must be performed in response to specific changes in the system’s context. (iii) A novel notion known as the context-aware class diagram is presented, which extends the traditional UML class diagrams to enable the representation of context information that affect the behaviours of a class. A new relationship, called utilisation, between a UML class and a context class is used to model context objects; meaning that the behaviours of the UML class depend upon the context information represented by the context class. Hence a context-aware class diagram is a rich and expressive language that distinctively depicts both the structure of classes and that of the contexts upon which they depend. The pragmatics of the proposed approach are demonstrated using two real-world case studies

Quality traceability for user-centric context-aware systems in intelligent environments

Context-awareness is an important component of modern software systems. For example, in Ambient Assisted Living (AAL), the concept of context-awareness empowers users by reducing their dependence on others. Due to this role in healthcare, such systems need to be reliable and usable by their intended users. Our research addresses the development, testing and validation of context-aware systems in an emerging field which currently lacks sufficient systems engineering processes and disciplines. One specific issue being that developers often focus on delivering a system that works at some level, rather than engineering a system that meets a specified set of system requirements and their corresponding qualities. Our research aims to contribute towards improving the delivery of system quality by tracing, developing and linking systems development data for requirements, contexts including sensors, test cases and their results, and user validation tests and their results. We refer to this approach as the “quality traceability of context-aware systems”. In order to support the developer, the quality traceability of context-aware systems introduces a systems development approach tailored to context-aware systems in intelligent environments, an automated system testing tool and system validation process. We have implemented a case study to inform the research. The case study is in healthcare and based on an AAL system used to remotely monitor and manage, in real time, an individual prone to depressive symptoms

Fine-tuning a context-aware system application by using user-centred design methods

Context-Aware Systems in the home environment can provide an effective solution for supporting wellbeing and autonomy for the elderly. The definition and implementation of the system architecture for a particular assisted living healthcare application entail both technological and usability challenges. If issues regarding users’ concerns and desires are taken into account in the early stages of the system development users can benefit substantially more from this technology. In this paper, we describe our initial experiences with different user-centred design methods, as they are applied in the process of fine-tuning a context-aware system architecture to improve quality of life for elderly THR patients (Total Hip Replacement). The insights resulting from this approach result in a clearer functional specification towards a better fit with the user needs regarding information need of the patient as well as the physiotherapist. Important system requirements as timing and content of the feedback are much more fruitful in an earlier phase of the development process. User-centred design methods help to better understand the needed functional features of a context-aware system, thereby saving time and helping developers to improve adoption of the system by the users

Modeling context aware features for pervasive computing

For more than two decades, research in the development of context-aware applications has gained significant attention, in which the context aware should be taken into account to adapt them to the requirements of the environment and users. However, advances in application models to support the development of these systems have not kept up. Researchers have been building and deploying context-aware applications with their behaviors often tailored to specific problem domains, by designing the anticipated context and the desired application behavior. Motivated by the raised facts, this paper presents a context aware model with ability to interact and to adapt smartly and dynamically to environment and needs of users. We are revisiting the context life cycle, especially the representation and the modeling of context features, regarding the relations within these features and the systems functionalities. Different kinds of components adaptation are described and scenarios are presented to illustrate these adaptations. As a proof of concept, we have simulated the context model in health care systems and show the results

The Design and Analysis of Context-Aware, Secure Workflow Systems

Workflows are set of activities that implement and realise business goals. Modern business goals add extra requirements on workflow systems and their management. Workflows may cross many organisations and utilise services on a variety of devices and/or supported by different platforms. Current workflows are therefore inherently context-aware. Each context is governed and constrained by its own policies and rules to prevent unauthorised participants from executing sensitive tasks and also to prevent tasks from accessing unauthorised services and/or data. We present a sound and multi-layered design language for the design and analysis of secure and context aware workflows systems

Architectural and Implementation Issues for a Context-Aware Hypermedia Platform

In this paper we present the rationale and the main components of a modular and extensible architecture for building and deploying mobile hypermedia software. Using some simple archetypical examples we show how to provide context-aware assistance to the mobile user, as he explores the physical world. We also show that this kind of software systems poses strong requirements on supporting software (such as Web browsers) and we explain how to provide a modular software substrate to support these requirements. This paper shows how to use some simple concepts to develop complex context-aware systems, which are evolvable and easy to extend.Facultad de InformáticaLaboratorio de Investigación y Formación en Informática Avanzada (LIFIA