Introducing requirements traceability support in model-driven development of web applications

In this work, we present an approach that introduces requirements traceability capabilities in the context of model-driven development of Web applications. This aspect allows us to define model-to-model transformations that not only provide a software artifact of lower abstraction (as model-to-model transformations usually do) but also to provide feedback about how they are applied. This feedback helps us to validate whether transformations are correctly applied. In particular, we present a model-to-model transformation that allows us to obtain navigational models of the Web engineering method OOWS from a requirements model. This transformation is defined as a set of mappings between these two models that have been implemented by means of graph transformations. The use of graph transformations allows us to develop a tool-supported strategy for applying mappings automatically. In addition, mechanisms for tracing requirements are also included in the definition of graph transformations. These mechanisms allow us to link each conceptual element to the requirements from which it is derived. In particular, we focus on tracing requirements throughout the navigational model, which describe the navigational structure of a Web application. To take advantage of these traceability mechanisms, we have developed a tool that obtains traceability reports after applying transformations. These reports help us to study aspects such as whether requirements are all supported, the impact of changing a requirement, or how requirements are modelled.     

Matching radio frequency identification tag compact dipole antennas to an arbitrary chip impedance

A method for matching dipole antennas to capacitive or inductive arbitrary complex impedances is proposed for ultra high frequency radio frequency identification (RFID) tag antenna designs. It can be applied to straight, capacitive-loaded, meander or any small high-Q dipole topology. For this purpose, design stages are provided with the corresponding formulas. The reflection coefficient simulations and measurements of four implemented prototypes show the expected output when the RFID frequency band, bandwidth, chip impedance and maximum tag size are required as inputs for the method. The eventual S11 < 10 dB bandwidth depends on the chip impedance Q factor and the antenna size. How this bandwidth is manifested in terms of the read range is also discussed. A length ratio of up to 31.1% regarding the standard Λ/2 dipole at resonance is obtained.     

Automating unobtrusive personalized services in ambient media environments

In the age of ambient media, people are surrounded by lots of physical objects (media objects) for rendering the digital world in the natural environment. These media objects should interact with users in a way that is not disturbing for them. To address this issue, this work presents a design and automation strategy for augmenting the world around us with personalized ambient media services that behave in a considerate manner. That is, ambient services are capable of adjusting its obtrusiveness level (i.e., the extent to which each service intrudes the user’s mind) by using the appropriate media objects for each user’s situation.     

Towards the Model Driven Development of context-aware pervasive systems

In this work, we introduce a Model Driven Development method for developing context-aware pervasive systems. This method allows us to specify a context-aware pervasive system at a high level of abstraction by means of a set of models, which describes both the system functionality and the context information. From these models, an automated code generation strategy is applied. This strategy allows us to generate the system Java code that provides the system functionality and as well as an OWL specification that represents the context information and allows us to manage this information without additional burden. Furthermore, this specification is used by a reasoner at runtime to infer context knowledge that is not directly observable, and it is also used by machine learning algorithms to give support to the system adaptation according to the context information.     

Designing for user attention: A method for supporting unobtrusive routine tasks

The automation of user routine tasks is one of the most important challenges in the development of Ambient Intelligence systems. However, this automation may be annoying since some tasks may grab users attention in inappropriate situations. Since user attention is a valuable resource, task automation must behave in a considerate manner demanding user attention only when it is required. To address this issue, this work presents a systematic method for supporting the design and automation of unobtrusive routine tasks that can adjust their obtrusiveness level at runtime according to the user attentional resources and context. This method proposes to design the routine tasks that the system must carry out and how they must interact with users in terms of obtrusiveness. The method also provides a software infrastructure that makes the execution of the tasks at the appropriate obtrusiveness degree a reality. Finally, the system has been validated by means of usefulness and performance tests and a practical case study that demonstrates the correctness and applicability of our approach without compromising system performance.     

A mobile-based solution for supporting end-users in the composition of services

Currently, technologies and applications evolve to create eco-systems made up of a myriad of heterogeneous and distributed services that are accessible anytime and anywhere. Even though these services can be used individually, it is their coordinated and combined usage what provide an added value to end-users. In addition, user’s wide adoption of mobile devices for daily activities have fostered a shift in the role played by end-users towards Internet data and services. However, existing solutions to service composition are not targeted to ordinary end-users. More easy-to-use tools have to be offered to end-users to make sure that they are successfully accepted and used by them. To this end, the work presented in this paper supports end-users in the creation of service compositions by using mobile devices. We present a Domain Specific Visual Language (DSVL) for end-users that allows them to create service compositions. A tool specifically designed for mobile devices supports this DSVL.     

SET Emulation Under a Quantized Delay Model

Single event transient (SET) fault analysis is usually performed through digital simulation at the gate level. However, this method cannot be used for large fault injection campaigns, since gate level simulation is quite slow. In this paper, we propose an approach to build an FPGA based SET emulator, which implements a quantized delay model of the circuit under evaluation. Experimental results demonstrate that the quantized delay model produces accurate results and can be easily captured in an FPGA. The proposed approach can be automated to increase SET fault analysis performance by three orders of magnitude with respect to simulation.

Design of UWB folded-plate monopole antennas based on TLM

From the current distribution on planar monopoles, transmission line modeling is applied to study this kind of antennas. Some reported techniques for broadband monopoles are approached by using this model from a qualitatively point of view. Conclusions are derived that help to match the monopoles over an ultrawide bandwidth regardless of whether they are folded or not. Folded configurations are obtained in order to provide solutions to specific designs and improve radiation pattern maintaining the planar monopole broadband behavior. Three compact folded prototypes with greater than 1:38 bandwidth are implemented and tested. Pulse distortion is also discussed for this type of applications.