Vicente Hernández

Self-adaptive systems: A survey of current approaches, research challenges and applications

Abstract Self-adaptive software is capable of evaluating and changing its own behavior, whenever the evaluation shows that the software is not accomplishing what it was intended to do, or when better functionality or performance may be possible. The topic of system adaptivity has been widely studied since the mid-60s and, over the past decade, several application areas and technologies relating to self-adaptivity have assumed greater importance. In all these initiatives, software has become the common element that introduces self-adaptability. Thus, the investigation of systematic software engineering approaches is necessary, in order to develop self-adaptive systems that may ideally be applied across multiple domains. The main goal of this study is to review recent progress on self-adaptivity from the standpoint of computer sciences and cybernetics, based on the analysis of state-of-the-art approaches reported in the literature. This review provides an over-arching, integrated view of computer science and software engineering foundations. Moreover, various methods and techniques currently applied in the design of self-adaptive systems are analyzed, as well as some European research initiatives and projects. Finally, the main bottlenecks for the effective application of self-adaptive technology, as well as a set of key research issues on this topic, are precisely identified, in order to overcome current constraints on the effective application of self-adaptivity in its emerging areas of application.

QoS in wireless sensor networks: survey and approach

A wireless sensor network (WSN) is a computer wireless network composed of spatially distributed and autonomous tiny nodes -- smart dust sensors, motes -, which cooperatively monitor physical or environmental conditions. Nowadays these kinds of networks support a wide range of applications, such as target tracking, security, environmental control, habitat monitoring, source detection, source localization, vehicular and traffic monitoring, health monitoring, building and industrial monitoring, etc. Many of these applications have strong requirements for end-to-end delay and losses during data transmissions. In this work we have classified the main mechanisms that have been proposed to provide Quality of Service (QoS) in WSN at Medium Access Control (MAC) and network layers. Finally, taking into account some particularities of the studied MAC- and network-layer protocols, we have selected a real application scenario in order to show how to choose an appropriate approach for guaranteeing performance in a WSN deployed application.

XML Schema Based Faultset Definition to Improve Faults Injection Tools Interoperability

This paper describes an XML schema formalization approach for the definition of basic fault sets which specify memory and/or register value corruption in microprocessor-based systems. SWIFI (software implemented fault injection) tools use fault injectors to carry out the fault injection campaign defined in a GUI-based application. However, the communication between the fault injector and the application is defined in an ad-hoc manner. Through this proposed XML schema definition different injectors could be used to carry out the same fault set injection. To validate this approach floating point register and memory corruptions with temporal triggers and routine interception mechanisms to carry out argument and return value, corruption has been considered. Moreover, an experimental tool called Exhaustifreg, consisting of a GUI Java application for defining the fault sets and injection policies and two injectors for SPARC and i386 architectures under RTEMS, has been developed. The XML-based approach improves the interoperability between SWIFI tools by uncoupling the injectors from the experiment manager in charge of the fault campaign.

Connectivity control in WSN based on fuzzy logic control

The connectivity of a wireless sensor network (WSN), specified as the percentage of nodes that are able to reach the base station (BS) that relays nodes data to other networks, has to be kept as high as possible, without either increasing significantly the energy consumption or worsening the WSN overall performance. Modelling accurately a WSN and designing a control system for accomplishing the desired network connectivity is an effortful task. In this paper, an approach based on fuzzy logic control is proposed, as it provides a better trade-off between accuracy, effort and time. The control system running in each node will manage both the communication range to guarantee a minimum number of neighbors called node degree, and the node degree itself, depending on the nodes battery level at each moment. The fuzzy controller running in a node will monitor the own nodes parameters, without flooding WSN with monitoring messages.

The DiY Smart Experiences Project

In this chapter we discuss the wide range of challenges in user-generated Internet of Things applications, as being worked on among the large consortium of the DiY Smart Experiences (DiYSE) project (DiYSE, ITEA2 08005). The chapter starts with a discussion on the context of ‘DiY’ as a phenomenon to be leveraged, and eco-awareness as an example application area. The main body of the chapter is devoted to the technical outline of the DiYSE architecture, starting at the lower Internet of Things layers of sensors, actuators and middleware, over the role of semantics in device and service interoperability, up to requirements for the service framework and the application creation process. Furthermore, the chapter adds considerations concerning tangible interaction in the smart space, assumed in Di- YSE both for the context of experiencing as well as shaping the user experience. With the chapter, we thus take a holistic view, sampling the range from lowerlayer technical implications of enabling DiY creation in the Internet of Things, up to the human-level aspects of creative communities as well as tangible interaction.

Wireless sensor networks in knowledge management

Abstract Research in Wireless Sensor Networks (WSN) necessarily touches on many research topics of Computer Science, Electronic Engineering and Telecommunication, basing on the existing work in related fields. However, the peculiarity of the WSN field is the interplay and integration of these foundation subjects, yielding a distinct topic worthy of further study in its own right. One of the main open issues in WSN research is to abstract the applications of complex low-level mechanisms, and one of the most powerful and flexible ways to achieve this is creating a Middleware layer that cover all this functionality, provide services to applications, allows the intercommunication among components, adapts dynamically to different operation modes and clearly differentiated from low-level components. Knowledge management and ontologies are also helpful when WSN are used to monitoring and taking decisions. We deploy a WSN in a testing scenario in order to control environmental parameters according to user profile stored in the system.

XML schema based fault set definition to improve fault injection tools interoperability

Software implemented fault injection tools (SWIFI) use fault injectors to carry out the fault injection campaign defined in a GUI-based application. However, the communication between the fault injector and the application is defined in an ad-hoc manner. This paper describes an XML schema formalisation approach for the definition of fault sets which specify low level memory and/or register value corruptions in embedded microprocessor-based systems and resource usage faults in host based systems. Through this proposed XML schema definition, different injectors could be used to carry out the same fault set injection. To validate this approach an experimental tool called Exhaustif®, consisting of a GUI Java application for defining the fault sets and injection policies, one injector for Windows hosts systems and two injectors for Sparc and i386 architectures under RTEMS have been developed.

Modelling QoS for wireless sensor networks

A wireless sensor network (WSN) is a wireless network composed of spatially distributed and tiny autonomous nodes — smart dust sensors, motes —, which cooperatively monitor physical or environmental conditions. Nowadays these kinds of networks support a wide range of applications, such as target tracking, security, environmental control, habitat monitoring, source detection, source localization, vehicular and traffic monitoring, health monitoring, building and industrial monitoring, etc. Generally, these applications have strong and strict requirements for end-to-end delaying and loosing during data transmissions. In this paper, we propose a realistic scenario for application of the WSN field in order to illustrate selection of an appropriate approach for guaranteeing performance in a WSN-deployed application. The methodology we have used includes four major phases: 1) Requirements analysis of the application scenario; 2) QoS modeling in different layers of the communications protocol stack and selection of more suitable QoS protocols and mechanisms; 3) Definition of a simulation model based on an application scenario, to which we applied the protocols and mechanisms selected in the phase 2; and 4) Validation of decisions by means of simulation and analysis of results. This work has been partially financed by the “Universidad Politecnica de Madrid” and the “ Comunidad de Madrid” in the framework of the project CRISAL - M0700204174.

SECUAREA: Security in physical and logical areas

Security is one of the major world wide concerns because of the terrorist attacks suffered in the last years. In fact, The European Commission has dedicated a Security specific programme within the 7th Framework Programme. New technologies bring about new capabilities and their use in conjunction with other technologies will provide us with brand new approaches to solve our actual security needs. Wireless sensor networks (WSN) are part of a new technology which is currently being researched and the first commercial solutions have started to appear. The capabilities of WSN can be easily foreseen as well as the wide range of possibilities of integrating sensor devices and actuators. On the other hand, RFID technology is becoming more and more extended in different applications. This paper shows the integration of WSN and RFID technologies to provide an integrated physical and logical security solution. The best of both technologies are put together into a unique solution directly applicable in those organizations which require high level of security.