Carlos Rodríguez-Domínguez

Enabling correct design and formal analysis of Ambient Assisted Living systems

Ambient Assisted Living (AAL) systems intend to provide services that enable people with specific needs to live an independent and safe life. Emergency treatment services are critical, time-constrained, and require compliance to numerous non-functional (or quality) requirements. In conventional approaches, often, non-functional requirements are kept outside the modeling scope and as such, their verification is also overlooked. For this reason, the specification and verification of Non-functional requirements (NFR) in this kind of services is a key issue. This paper presents a verification approach based on timed traces semantics and a methodology based on UML-RT models (MEDISTAM-RT) to check the fulfillment of non-functional requirements, such as timeliness and safety (deadlock freeness), and to assure the correct functioning of the AAL systems. We validate this approach by its application to an Emergency Assistance System for monitoring people suffering from cardiac alteration with syncope.

A Communication Model to Integrate the Request-Response and the Publish-Subscribe Paradigms into Ubiquitous Systems

The Request-Response (RR) paradigm is widely used in ubiquitous systems to exchange information in a secure, reliable and timely manner. Nonetheless, there is also an emerging need for adopting the Publish-Subscribe (PubSub) paradigm in this kind of systems, due to the advantages that this paradigm offers in supporting mobility by means of asynchronous, non-blocking and one-to-many message distribution semantics for event notification. This paper analyzes the strengths and weaknesses of both the RR and PubSub paradigms to support communications in ubiquitous systems and proposes an abstract communication model in order to enable their seamless integration. Thus, developers will be focused on communication semantics and the required quality properties, rather than be concerned about specific communication mechanisms. The aim is to provide developers with abstractions intended to decrease the complexity of integrating different communication paradigms commonly needed in ubiquitous systems. The proposal has been applied to implement a middleware and a real home automation system to show its applicability and benefits.

A Context-Aware Architecture Supporting Service Availability in Mobile Cloud Computing

Mobile systems are gaining more and more importance, and new promising paradigms like Mobile Cloud Computing are emerging. Mobile Cloud Computing provides an infrastructure where data storage and processing could happen outside the mobile node. Specifically, there is a major interest in the use of the services obtained by taking advantage of the distributed resource pooling provided by nearby mobile nodes in a transparent way. This kind of systems is useful in application domains such as emergencies, education and tourism. However, these systems are commonly based on dynamic network topologies, in which disconnections and network partitions can occur frequently, and thus the availability of the services is usually compromised. Techniques and methods from Autonomic Computing can be applied to Mobile Cloud Computing to build dependable service models taking into account changes in the context. In this work, a context-aware software architecture is proposed to support the availability of the services deployed in mobile and dynamic network environments. The proposal is based on a service replication scheme together with a self-configuration approach for the activation/hibernation of the replicas of the service depending on relevant context information from the mobile system. To that end, an election algorithm has been designed and implemented.

Towards a Reusable Design of a Positioning System for AAL Environments

There exists a large diversity of decisions to be dealt with in the design and construction of positioning systems, each of them implying different advantages and disadvantages. We present a design proposal which aims to provide reusable and adaptable support to Location-based Systems, through a reconfigurable positioning service composed of interoperable components. The interest of the proposal concerns the combination between different methods, algorithms and technologies to be selected in run-time so as to take advantage of the benefits of each one of them. The positioning system aims to use that technology which is more beneficial taking into account the quality properties that need to be fulfilled at a given time. For instance, the proposal enables AAL solutions to address indoor and outdoor positioning by means of the same service switching dynamically and automatically between methods and technologies, and combine two different methods simultaneously to improve accuracy. This research work also describe results obtained from a competition with other proposals.

A Model-Driven Approach to Requirements Engineering in Ubiquitous Systems

Non-Functional Requirements (NFRs) are of paramount importance for the success of Ubiquitous Systems. However, existing methods and techniques to engineer these systems lack support in their specific and systematic treatment. In this paper, a specification technique and several models are introduced to deal with NFRs paying special attention to those particulary related to the features of Ambient Intelligence (AmI) and Ubiquitous Computing (UC). A Model-Driven approach is followed in order to enable the derivation of software designs for such systems. To this end, formal models and methods are defined, as well as an evaluation procedure to be applied, which aims to help designers to select the most appropriate solutions towards the satisfaction of quality attributes.

Serious games for the cognitive stimulation of elderly people

Elderly people can suffer some degree of decline in their cognitive capacities, usually including different symptoms (decreased problem solving capacity, decreased ability to reason and to maintain focus, forgetfulness, etc.). Cognitive stimulation has been shown to decrease the rate of intellectual decay and potentially reverse age-related cognitive decline. Serious games provide new training opportunities to improve the decrease in selected social, sensory-motor, cognitive and emotional functions of elderly people. This paper details the objectives of the VIRTRA-EL web platform, which has been designed to evaluate and train cognitive skills to elderly users by means of serious games using the personal computer or tablet devices. Additionally, we present a serious game based on interactive 3D environments, which has been designed with the aim of helping to train memory, attention, planning and reasoning.

Dynamic Replication and Deployment of Services in Mobile Environments

Currently, mobile environments are gaining importance, and new promising paradigms, like Mobile Cloud, are arising. However, these environments pose new challenges and are mainly characterized, among others, by frequent changes in their execution context. This particularly is challenging for software architects in the design and implement this kind of systems. For instance, the Service Oriented Architecture (SOA) paradigm has not been devised to operate in dynamic network environments, where centralized services or static deployments must be avoided, in order to provide a higher availability of services. Therefore, in order to provide a reliable SOA implementation in mobile environments, it must be complemented with techniques and methods of Autonomic Computing. In this work, a self-adaptive SOA approach is proposed. This architecture will provide support to the dynamic replication and deployment of services in mobile environments. The approach is based on the context information modelling and management as key aspect to achieve the required architecture adaptation.

Context-Aware Self-adaptations: From Requirements Specification to Code Generation

Embedding context-aware self-adaptation mechanisms in pervasive systems is key to improve their acceptance by the users. These mechanisms involve a precise definition of the software structures that enable adding, removing or replacing components of the system to perform the adaptations. Typically the definition of these mechanisms is a complex and time consuming task. This paper presents a model-driven engineering approach to generate these context-aware self-adaptation mechanisms. The use of models transformations to define these mechanisms helps to reduce the complexity and effort required to define them. In order to illustrate the usefulness of the proposed approach, this paper reports its application to the development of a context-aware notification service.

Designing a Service Platform for Sharing Internet Resources in MANETs

Nowadays, there is great interest to develop future Internet applications supporting resource sharing in mobile networks. This usually entails maintaining the consistency of those shared resources, that is, between different replicas of the resources. Moreover, mobile networks are characterized by varying capacity, in part, caused by their mobility, which also derives in frequent networking disconnections and network partitions. Therefore, to ensure the consistency of replicated resources being shared in a mobile network is more complicated that in networks with infrastructure support, as it requires to process events associated with the use of the resources themselves as well as those related with the state of the network. In response, in this paper an event-driven platform consisting of two services (monitoring and synchronization) and an underlying middleware has been designed in order to address the consistency of shared Internet resources in mobile networks in a simple way. The synchronization service only needs to be specialized to adapt the resource, depending on its type, to the required use in a particular system. The proposal is illustrated through the example of a collaborative document editor.

Designing a Communication Platform for Ubiquitous Systems: The Case Study of a Mobile Forensic Workspace

The ubiquitous computing is a human-computer interaction model in which information systems (i.e., ubiquitous, pervasive or ambient intelligence systems) are seamlessly integrated into the lifestyle of the user. In particular, these systems offer information about the user context and cooperate with other systems to facilitate some everyday tasks. As a consequence, interoperability is a key requirement for them, since it is usually necessary to exchange information between heterogeneous platforms (operating systems, middleware solutions, hardware architectures, etc.). Interoperability requirements are usually fulfilled by establishing shared communication protocols (SOAP, JSON, IIOP, and so on) and connection mechanisms (for instance, Wi-Fi or BlueTooth). Therefore, the software trends to be highly bond to specific communication-related technologies, making it increasingly complex to incorporate future communication technologies that could enhance its quality. In this paper we present several platform independent models to overcome this problem by decreasing the level of cohesion between communication technologies and software for ubiquitous computing. As a case study, and to show their applicability, the models have been implemented through specific technologies to support the development of a mobile forensic workspace.